Assessing the sustainability of bioethanol production in different development contexts

Assessing the sustainability of bioethanol production in different development contexts
TRITA-ECS 2013-01
KTH 2013
www.kth.se
Dilip Khatiwada Assessing the sustainability of bioethanol production in different development contexts: A systems approach
ISBN 978-91-7501-823-2
Assessing the sustainability
of bioethanol production
in different development
contexts
A systems approach
D i l i p K h at i wa d a
Doctoral Thesis in Energy Technology
Energy and Climate Studies
Stockholm, Sweden 2013
Assessing the sustainability of
bioethanol production
in different development contexts
A systems approach
Dilip Khatiwada
Doctoral Thesis 2013
KTH Royal Institute of Technology
School of Industrial Engineering and Management
Department of Energy Technology/Energy and Climate Studies Unit
SE-100 44 Stockholm, Sweden
Printed in Sweden
Universitetsservice US-AB
Stockholm, 2013
ISBN 978-91-7501-823-2
TRITA-ECS 2013-01
© Dilip Khatiwada, 2013
To my parents
Late Badri Prasad Khatiwada (Father)
Late Narbada Devi Khatiwada (Mother)
&
To my beloved uncle
Late Prof. Agni Prasad Rijal
Sustainability of bioethanol production in different development contexts: A systems approach
Abstract
The continuous depletion of fossil fuel reserves, the global agenda on
climate change and threats to energy security have led to increased global
interest in the exploration, production and utilisation of bioenergy and
biofuels. Access to modern bioenergy carriers derived from the efficient
conversion of locally available biomass resources is indispensable for
economic growth, rural development and sustainable development in
developing countries. Deployment of bioenergy/biofuels technologies
has significantly varied across the globe. The least developed countries
(LDCs) and developing countries are still highly dependent on traditional
biomass technologies with low conversion efficiency, which are typically
associated with significant environmental and health impacts. Meanwhile,
emerging economies and developed countries are progressively promoting biofuel industries and international trade. They are also engaged in
making biofuels a sustainable proposition by developing sustainability
criteria. The goal of this thesis is to address the sustainability of bioethanol production derived from one of the key feedstocks/energy crops:
sugarcane. This will be done by analysing different development contexts
and environmental constraints in terms of geopolitical situation, economic development and state-of-the-art technologies in agro-industrial
development. Life cycle assessment (LCA), system studies, and technoeconomic optimisation are the main methodological approaches applied
in the thesis. The thesis primarily addresses three key questions for analysing the sustainability of bioethanol production.
The first research question investigates the key parameters affecting the
sustainability of bioethanol production and use in a low-income country
using the case of Nepal. The net energy and greenhouse gas (GHG) balances are identified to be the main sustainability criteria of the sugarcanemolasses bioethanol (Paper I and II). Results of the lifecycle studies
show that the production of bioethanol is energy-efficient in terms of the
fossil fuel inputs required to produce the renewable fuel. Greenhouse gas
(GHG) emissions from the production and combustion of ethanol are
also lower than those from gasoline. The study also evaluates the socioeconomic and environmental benefits of ethanol production and use in
Nepal, concluding that the major sustainability indicators are in line with
the goals of sustainable development (Paper III). Assessment of the biofuel (molasses-bioethanol) sustainability in Nepal is the first of its kind in
i
Doc t oral Thes is / Dilip Khat iwa da
low-income countries, and serves also the purpose of motivating the assessment of ethanol production potential in other LDCs, particularly in
sub-Saharan Africa.
The second question critically evaluates methodologies for accounting
the lifecycle GHG emissions of Brazilian sugarcane ethanol in European
and American regulations, depicting commonalities and differences
among them (Paper IV). GHG emissions are becoming increasingly important as part of sustainability criteria in the context of the expansion of
biofuel production and international trade. However, different methodologies still lead to quite different results and interpretation. To make
this an operational criterion for international comparisons, it is necessary
to establish unified methodological procedures for accounting GHG
emissions. The thesis identifies the major issues as N2O emissions from
agricultural practices, bioelectricity credits in fuel production, and modelling approaches in estimating emissions related to direct and indirect land
use change (LUC & iLUC), that need to be addressed for establishing
methodological coherences.
The third research question investigates how the sugarcane bioethanol
industry can be developed in terms of energy security and the diversification of energy sources. The case of complementarity between bioelectricity and hydropower is evaluated in the cases of Nepal and Brazil and presented in Paper V. Bioelectricity could offer a significant share of electricity supply in both countries provided that favourable political and institutional conditions are applied. Finally, in order to find the choice of
technological options for the production of second generation (2G) bioethanol and/or of bioelectricity, a techno-economic optimisation study
on the bulk of sugarcane bio-refineries in Brazil is carried out in Paper
VI, taking into account the entire lifecycle costs, emissions, and international trade. The study shows that it is worthwhile to upgrade sugarcane
bio-refineries. Energy prices, type of power generation systems, biofuel
support and carbon tax, and conversion efficiencies are the major factors
influencing the technological choice and potential bioethanol trade.
In short, this dissertation provides insights on the sustainability of the
bioethanol production/industry and its potential role in the mitigation of
climate change, improved energy security and sustainable development in
different country contexts, as well as methodological contributions for
assessing the sustainability of biofuels production in connection with energy and climate policies.
Keywords: bioenergy and biofuel, bioethanol industry, development trend, sustainability assessment, climate change mitigation, energy security, life cycle assessment, systems optimisation
ii
Sustainability of bioethanol production in different development contexts: A systems approach
Sammanfattning
Intresset för ökad exploatering, produktion och användning av bioenergi
och biobränslen har föranletts av den kontinuerliga utmattningen av fossila bränslen, den globala agendan för att motverka klimatförändringar
samt hoten mot energisäkerheten. Tillgången till moderna bioenergibärare, effektivt framställda från lokal råvara, är grundläggande för ekonomisk tillväxt, landsbygdsutveckling samt för hållbar utveckling i utvecklingsländer. Användandet av bioenergi- och biobränsleteknologi har varierat markant världen över. De minst utvecklade länderna (LDCs) samt
övriga utvecklingsländer är fortfarande beroende av traditionella biomassabaserade tekniker till stor utsträckning. Dessa tekniker har låg effektivitet och är ofta sammankopplade med stora miljö- och hälsoskador. Samtidigt främjar tillväxtekonomier och utvecklingsländer biobränsleindustrin och internationell handel progressivt. Länderna arbetar även för att
biobränslen ska bli ett hållbart alternativ genom att utveckla hållbarhetskriterier. Den här avhandlingens mål är att adressera hållbarheten hos
bioetanolproduktion från sockerrör, en av bioetanolens nyckelråvaror.
Målet kommer att nås genom analyser av industrins nationella utvecklingsmiljö samt miljö- och klimatmässiga begränsningar som härstammar
från den geopolitiska situationen och den ekonomiska tillväxten i landet,
samt analyser av teknologier i den agro-industriella utvecklingen. De huvudsakliga metoder som använts är livscykelanalys (LCA), systemstudier
och tekno-ekonomisk optimering. Avhandlingen adresserar primärt tre
nyckelfrågor för att analysera hållbarheten hos bioetanolproduktion.
Den första forskningsfrågan belyser hur nyckelparametrar påverkar hållbarheten hos produktion och användning av bioetanol i låginkomstländer, med fallstudien Nepal som utgångspunkt. Nettoenergi- och växthusgasbalanser identifieras som de huvudsakliga hållbarhetskriterierna
för sockerrör-melass-baserad bioetanol (Artikel I och II). Livscykelstudiernas resultat visar att produktionen av bioetanol är energieffektiv sett
från den mängd fossila bränslen som produktionen av förnybart bränsle
krävt. Växthusgasutsläppen från produktion och förbränning av etanol är
dessutom lägre än utsläppen från bensin. Studien utvärderar de socioekonomiska och miljö- och klimatmässiga fördelarna med produktion
och användning av etanol i Nepal. Slutsatsen är att indikatorerna för
hållbarhet ligger i linje med målen för hållbar utveckling (Artikel III).
Bedömningen av biobränslens (melass-baserad etanol) hållbarhet i Nepal
iii
Doc t oral Thes is / Dilip Khat iwa da
är den första studien i sitt slag för låginkomstländer. Studien motiverar
dessutom en bedömning av potentialen för etanolproduktion i andra
LDCs, speciellt i de afrikanska länderna söder om Sahara.
Den andra forskningsfrågan kräver en kritisk utvärdering av metoderna
för hur livscykelutsläpp från brasiliansk sockerrörsetanol redovisas i
europeiska och amerikanska regleringar (Artikel IV). Artikeln, som påvisar likheter och skillnader mellan regionerna, visar att växthusgasutsläpp
blir en mer och mer viktig del i hur hållbarhetskriterier definieras när expansionen av biobränsleproduktion och internationell handel diskuteras.
Olika metoder för redovisningen av växthusgasutsläpp leder dock till
mycket olika resultat och tolkningar. Det är nödvändigt att etablera en
enhetlig metod för redovisning av växthusgasutsläpp för att skapa ett kriterium som möjliggör internationella jämförelser. Avhandlingen identifierar de mest beaktansvärda problemen för att etablera en enhetlig metod:
N2O-utsläpp från jordbruksprocesser, tillgodoräknande av bioelektricitet
inom bränsleproduktion, samt modelleringsmetoder för att uppskatta utsläpp relaterade till direkt och indirekt landanvändning (LUC och iLUC).
Den tredje forskningsfrågan utreder hur industrin för sockerrörsbioetanol kan utvecklas från ett energisäkerhetsperspektiv, med speciell hänsyn
till diversifieringen av energikällor. I Artikel V presenteras hur bioelektricitetsproduktion och vattenkraft kan komplettera varandra i fallen Nepal
och Brasilien. Bioelektricitet skulle kunna bidra markant till tillförseln av
elektricitet i båda länderna under förutsättning att de politiska och institutionella förutsättningarna är fördelaktiga. Slutligen utförs en teknoekonomisk studie för att identifiera den optimala teknologin för produktion av andra generationens (2G) bioetanol och/eller bioelektricitet. Studien görs för merparten av sockerrörsbioraffinaderierna i Brasilien och
utgör Artikel VI. Studien tar fullskaliga livscykelkostnader i beaktande
samt utsläpp och internationell handel. Studien visar att det är värt mödan att uppgradera befintliga sockerrörsbioraffinaderier. De dominerande påverkansfaktorerna för valet av teknologi och potentialen för
bioetanolhandel är energipriser, typ av kraftproduktionssystem,
biobränslestöd och koldioxidskatt, samt processernas effektivitet.
Kortfattat behandlar den här avhandlingen bioetanolproduktionens och
bioetanolindustrins hållbarhet. Avhandlingen ger insikt i dess potentiella
roll för att motverka klimatförändringar, förbättra energisäkerhet samt
främja hållbar utveckling i olika nationella sammanhang. Avhandlingen
bidrar dessutom med metodutveckling i hur hållbarheten av biobränsleproduktion bedöms inom ramen för energi- och klimatpolicy.
Nyckelord: bioenergi och biobränsle, bioetanolindustri, utvecklingstrender, hållbarhetsbedömning, motverka klimatförändringar, energisäkerhet, livscykelanalys, systemoptimering
iv
Sustainability of bioethanol production in different development contexts: A systems approach
Preface
This PhD dissertation has been developed at the Energy and Climate
Studies (ECS) Unit, Department of Energy Technology, School of Industrial Engineering and Management at KTH – Royal Institute of
Technology, within the framework of the Global Energy and Climate
Studies Program, supported by the Swedish Energy Agency. Research at
ECS has an interdisciplinary character with a strong systems-based approach dealing with cross-cutting issues of sustainable energy systems,
viz. energy, climate change and sustainable development.
Part of this PhD study is developed at the Bioethanol Science and Technology Laboratory (CTBE) in Brazil and International Institute for Applied Systems Analysis (IIASA) in Austria. The research period at CTBE
has been mainly funded by a scholarship from the Brazilian National
Council for Scientific and Technological Development (CNPq), while
the Swedish Research Council provided a travel grant to participate in
the IIASA’s Young Scientists Summer Program 2012.
It is important to analyse the sustainability aspects of the bioenergy systems when LDCs and many developing countries are living with energy
and food poverty, whilst endeavouring to sustain their livelihoods and
achieve sustainable development goals. In this thesis, the sustainability
paradigm of bioethanol production with regard to environmental stewardship, economic prosperity, and social integrity is dealt with in different development contexts. In this sense, the cases of Nepal and Brazil
are used to illustrate that, despite very different development contexts, a
common ground can be found on how to base the sustainable expansion
of modern biofuels, such as bioethanol.
v
Doc t oral Thes is / Dilip Khat iwa da
Publications
The current doctoral thesis is based on the following publications, which
are appended at the end of the thesis:
I.
Paper - I: Khatiwada, D., Silveira S., 2009. Net energy balance of
molasses based ethanol: The case of Nepal. Renewable and Sustainable Energy Reviews 13, pp. 2515-2524. [Available online at Elsevier's www.sciencedirect.com]
II. Paper - II: Khatiwada, D., Silveira S., 2011. Greenhouse gas balances of molasses based ethanol in Nepal. Journal of Cleaner Production 19, pp. 1471-1485. [Available online at Elsevier's
www.sciencedirect.com]
III. Paper - III: Silveira, S., Khatiwada, D., 2010. Ethanol production
and fuel substitution in Nepal—Opportunity to promote sustainable development and climate change mitigation. Renewable and
Sustainable Energy Reviews 14, pp. 1644-1652. [Available online at
Elsevier's www.sciencedirect.com]
IV. Paper - IV: Khatiwada, D., Seabra, J., Silveira, S., Walter, A., 2012.
Accounting greenhouse gas emissions in the lifecycle of Brazilian
sugarcane bioethanol: Methodological references in European and
American regulations. Energy Policy 47, pp. 384-397. [Available
online at Elsevier's www.sciencedirect.com]
V.
Paper - V: Khatiwada, D., Seabra, J., Silveira, S., Walter, A., 2012.
Power generation from sugarcane biomass – A complementary
option to hydroelectricity in Nepal and Brazil. Energy 48, pp. 241254. [Available online at Elsevier's www.sciencedirect.com]
VI. Paper - VI: Khatiwada, D., Leduc, S., McCallum, I., Silveira, S.,
2012. Optimizing ethanol and bioelectricity production in sugarcane
biorefineries in Brazil (under review). Draft manuscript of this paper is appended in the thesis.
Contribution of this thesis author on the papers is as follows:
Paper I-II: The thesis author was the main author; research framework,
field works, analysis, and interpretation were done by the thesis author. The second author acted as mentor and reviewer.
Paper III: The thesis author was second author; field works, data collection, estimation of technical figures and their interpretation were
carried out by the thesis author. The first author contributed to
formulation of the research framework, and acted as mentor and
vi
Sustainability of bioethanol production in different development contexts: A systems approach
reviewer for this author’s fieldwork, interpretation, and other calculations.
Paper IV: The thesis author was the main author; research framework,
analysis, and interpretation were done by the thesis author. The
second, third and fourth authors acted as mentors and reviewers.
Paper V: The thesis author was the main author; research framework,
analysis, and interpretation were done by the thesis author. The
second, third and fourth authors acted as mentors and reviewers.
Paper VI: The thesis author was the main author; research framework,
analysis, and interpretation were done by the thesis author. The
second author did the main part of the modelling work on the optimisation model. The thesis author also contributed to model development, as well as developed scenarios and performed most of
the model runs. The third and fourth authors acted as mentors and
reviewers.
Other publications related to the PhD thesis
I.
Khatiwada, D., Silveira, S., 2010. Assessing the sustainability of
bioethanol production: Key criteria and methodological
improvements (Poster). Energy Day, December 2010. KTH Royal Institute of Technology, Sweden.
II.
Pacini, H., Khatiwada, D., Lönnqvist, T., 2010. Trade
dimensions of small-scale biofuel production in developing
countries, International Centre of Trade and Sustainable
Development (ICTSD), Geneva, Switzerland.
III.
Khatiwada, D., Seabra, J., Silveira, S., Walter, A., 2011. Power
generation from sugarcane biomass – a complementary option
to hydroelectricity in Nepal and Brazil (Conference
presentation), the 6th Dubrovnik Conference on Sustainable
Development of Energy, Water and Environment System,
September 25 - 29, 2011, Dubrovnik, Croatia.
IV.
Silveira, S., Khatiwada, D., 2011. The role of ethanol from
sugarcane in mitigating climate change and promoting
sustainable development in LDCs – the case of Nepal.
Bioenergy for Sustainable Development and International
Competitiveness: the Role of Sugar Cane in Africa, Johnson,
F.X. and Seebaluck, V. (eds.), Earthscan, pp. 350-368.
V.
Silveira, S., Mainali, B., Khatiwada, D., 2011. Green energy for
development in Nepal, UNCTAD publication (Rio+20, 2nd
volume), pp. 79-83.
vii
Doc t oral Thes is / Dilip Khat iwa da
VI.
Khatiwada, D., Seabra, J., Silveira, S., Walter, A., 2011.
Methodologies for accounting greenhouse gas emissions of
bioethanol production in Brazil (Conference presentation),
International Symposium on Alcohol Fuels (ISAF XIX), 10-14
October 2011, Verona, Italy.
VII.
Khatiwada, D., Sylvain, L., McCallum, I., Silveira, S., 2012.
Optimizing second generation bioethanol production in
sugarcane biorefineries in Brazil (poster). 40th IIASA
conference, October, 2012. International Institute for Applied
Systems Analysis (IIASA), Austria.
VIII.
Khatiwada, D., Sylvain, L., McCallum, I., Silveira, S., 2012.
Optimizing energy production in sugarcane biorefineries in
Brazil (poster). Energy Dialogue, November 2012, KTH - Royal
Institute of Technology, Sweden.
IX.
Khatiwada, D., 2012. Optimizing ethanol and bioelectricity
production in sugarcane biorefineries. Interim Report/paper.
Ecosystems Services and Management Programme (ESM),
International Institute for Applied Systems Analysis (IIASA),
Austria.
viii
Sustainability of bioethanol production in different development contexts: A systems approach
Acknowledgements
First of all, I would like to express my profound gratitude and sincere
appreciation to my thesis supervisor Prof. Dr. Semida Silveira for inviting me to join her research team at the Energy and Climate Studies
(ECS) Unit as a PhD candidate and for her unparalleled guidance, support and creative suggestions throughout my research period. My PhD is
the outcome of her insightful embellishments and enduring supervision
to my work. In addition, I am very grateful to my second supervisors
Prof. Andrew Martin and Prof. Mark Howells at the Department of Energy Technology.
I would like to thank Prof. Arnaldo Walter for his unconditional support,
valuable ideas and guidance both in professional and personal level
throughout my one-year research period in Brazil. I am greatly thankful
to Prof. Joaquim Seabra for his guidance, valuable suggestions and encouragement. And, thanks to all my colleagues Regis, Pedro, Simone,
Cinthia, Camila, and Marcelo of CTBE, Brazil for their time and effort
spent in making my stay worthy and memorable.
I am grateful to Dr. Leduc Sylvain and Ian McCallum for supervising
my work at Ecosystems Services and Management Program
(ESM)/IIASA. I really appreciate Dr. Sylvain for providing valuable
guidance on the development of the techno-economic model ‘BeWhere’
described in this thesis. I would like to thank all YSSP-2012 colleagues
and the staff at the ESM program, who made it possible for me to
spend an unforgettable and enjoyable research period at IIASA.
I would like to thank my colleagues Brijesh, Francis, Johannes, Maria, Allesandro, Tomas, Henrique and Edgard at ECS for creating a very pleasant and creative environment to work in and for all the good memories
that I will cherish for the rest of my life. Thank you for always being
there!
Special thanks goes to Mr. Rishi Raj Koirala, Joint Secretary and other
colleagues at the Ministry of Industry, Government of Nepal for providing support and encouragement during this research period.
I am very thankful to my whole family: my brothers, my sisters, and my
in-laws for their unconditional love, support, and encouragement. I
would like to express my sincere gratitude to my wife Ruchita and beloved son Shreyash for their love, endurance, moral support and patience.
ix
Doc t oral Thes is / Dilip Khat iwa da
Besides thanking all the wonderful people around me, I would like to
take this opportunity to thank late prof. Agni Prasad Rijal, who has been
a true inspiration and influence in every step of my life. His philosophy
of living a life has always extended my way of thinking and brought a
new insight to look into this world. His immortal love and blessings have
always strengthened me to face the challenges. I dedicate my work to all
his immense effort, care, support, guidance and love provided throughout my life. Thanks for being a true mentor. You will always be missed!!
Last but not least, this thesis is also a beautiful way to thank my beloved
parents late Badri Prasad Khatiwada and Late Narbada Devi Khatiwada
for bringing me into this world!!
Thank you!
Dilip Khatiwada
September 2013, Stockholm
Sweden
x
Sustainability of bioethanol production in different development contexts: A systems approach
Abbreviations and Nomenclature
1G
2G
AC
ADP
BEFS
BIG-CC
BLUM
BSI
CA-CARB
CBI
CDM
CEN
CER
CEST
CH4
CHP
CO
CO2
CO2eq
COD
CTBE
CTC
E10
E20
EC
ECS
Ef
Ei
EISA
EPA
EtOH
ETP
First Generation
Second Generation
Annualised Cost
Anaerobic Digestion Process
Bioenergy and Food Security
Biomass Integrated Gasification Combined Cycle
Brazilian Land Use Model
Better Sugarcane Initiative
California Air Resources Board
Caribbean Basin Initiative
Cleaner Development Mechanism
European Committee for Standardisation
Certified Emission Reduction
Condensing-cum-Extraction Steam Turbine
Methane
Combined Heat and Power
Carbon Monoxide
Carbon Dioxide
Carbon Dioxide Equivalent
Chemical Oxygen Demand
Brazilian Bioethanol Science and Technology Laboratory
(Portuguese: Laboratório Nacional de Ciência e Tecnologia do Bioetanol)
Sugar Cane Technology Center (Portuguese acronym:
Centro de Tecnologia Canavieira)
10% ethanol and 90 % gasoline (v/v)
20% ethanol and 80% gasoline (v/v)
European Commission
Energy and Climate Studies
Lower Heating Value of Fuel ethanol
Primary Energy Inputs
Energy Independence and Security Act
Environment Protection Agency
Ethanol (>99.5% v/v), E100 or MOE
Effluent Treatment Plant
xi
Doc t oral Thes is / Dilip Khat iwa da
EU
EUBIA
FAO
FAPRICARD
GBEP
gCO2eq
GHG
GJ
GoN
GTAP
GWh
GWP
Ha
IAEA
ICONE
IEA
IIASA
iLUC
IPCC
IPP
IR
ISCC
ISO
K2O
Kcal
kg
kgCO2eq
KJ/kg
KL
kW
kWh
L
LCA
LCC
LCFS
LCSA
European Union
European Biomass Industry Association
United Nations Food and Agricultural Organisation
Food and Agricultural Policy Research Institute - Center
for Agricultural and Rural Development
Global Bioenergy Partnership
gram- Carbon Dioxide Equivalent
Greenhouse Gas
Giga Joule
Government of Nepal
Global Trade Analysis Project
Gigawatt-hour
Global Warming Potential
Hectare, also ha
International Atomic Energy Agency
Institute of International Trade Negotiations
International Energy Agency
International Institute for Applied Systems Analysis
Indirect Land Use Change
Intergovernmental Panel on Climate Change
Independent Power Producers
Interest Rate
International Sustainability and Carbon Certification
International Standards for Organisation
Potash
Kilocalorie
Kilogram
kg Carbon Dioxide Equivalent
Kilo Joule per Kilogram
Kilo-litre
Kilowatt
Kilowatt-hour
Litre
Life Cycle Assessment
Life Cycle Costing
Low Carbon Fuel Standard
Life Cycle Sustainability Assessment
xii
Sustainability of bioethanol production in different development contexts: A systems approach
LDCs
LUC
m3
m-3
MDGs
MILP
MJ
MJ/L
MJ-1
MME
MOE
Mt
MW
MWh
N
N2O
NEB
NEi
NEV
NGO
Nm3
NOC
NOx
NPV
NREL
NREV
OECD
P2O5
PJ
PM10
PM2.5
PPP
PS
RED
RFS
RSB
Least Developed Countries
Land Use Change
Cubic Meter
Per Cubic Meter
Millennium Development Goals
Mixed Integer Linear Program
Mega Joule
Mega-joule per Litre
Per Mega-joule
Ministry of Mines and Energy
Molasses Based Ethanol or EtOH
Million tonne
Megawatt
Megawatt-hour
Nitrogen
Nitrous Oxide
Net Energy Balance or NEV
Non-Renewable or Fossil Fuel Inputs
Net Energy Value or NEB
Non-Governmental Organisation
Normal Cubic Meter
Nepal Oil Corporation
Nitrogen Oxides
Net Present Value
National Renewable Energy Laboratory
Net Renewable Energy Value or Balance
Organisation for Economic Co-operation and Development
Phosphorous
Peta Joule
Particulate matter with a diameter of less than 10 µm
Particulate matter with a diameter of less than 2.5 µm
Public Private Partnership
Pond Stabilisation
Renewable Energy Directive
Renewable Fuel Standard
Roundtable on Sustainable Biofuels
xiii
Doc t oral Thes is / Dilip Khat iwa da
RSPO
RTFO
RTRS
SD
SLCA
SOx
SP
SRSM
t-cane
tCO2eq
TIC
t-km
Tonne/hr
TPES
TWh
UK
UN
UNCSD
UNCTAD
UNDESA
UNDP
UNEP
UNFCCC
UNICA
US
USD($)
v/v
w/w
WCED
WECS
y-1
Roundtable on Sustainable Palm Oil
Renewable Transport Fuels Obligation
Roundtable for Responsible Soy Production
Sustainable Development
Social Life Cycle Assessment
Sulphur Oxides
Sao Paulo
Sri Ram Sugar Mills Pvt. Ltd.
tonne-sugarcane
tonne-Carbon Dioxide Equivalent
Total Investment Costs
tonne-kilometre
Tonne (=1000 kg) per hour
Total Primary Energy Supply
Terawatt-hour
United Kingdom
United Nations
United Nations Conference on Sustainable Development
United Nations Conference on Trade and Development
United Nations Department of Economic and Social Affairs
United Nations Development Program
United Nations Environment Program
United Nations Framework Convention on Climate
Change
Brazilian Sugarcane Industry Association (Portuguese:
União da Indústria de Cana-de-Açúcar)
United States of America
US Dollar
Volume by Volume
Weight by Weight
World Commission on Environment and Development
Water and Energy Commission Secretariat
Per year
xiv
Sustainability of bioethanol production in different development contexts: A systems approach
Table of contents
Abstract ............................................................................................ i
Sammanfattning ............................................................................. iii
Preface ..............................................................................................v
Table of contents ............................................................................ xv
Index of Figures ...........................................................................xvii
Index of Tables............................................................................. xix
1 Introduction .................................................................................. 1
1.1
Background ................................................................... 1
1.2
Objective and research questions .............................. 5
1.3
Development of case studies in Nepal and Brazil .. 6
1.4
Scope of the thesis ....................................................... 9
1.5
Outline of the thesis ..................................................13
2 State-of-the-art systems in biofuel production ........................... 17
2.1
Bioenergy and biofuels: An overview .....................17
2.2
Biofuel production .....................................................20
2.3
Bioethanol as a transport fuel ..................................23
2.4
Biorefinery and sugarcane bioenergy systems .......24
3 Sustainability assessment: Concepts and frameworks ............... 29
3.1
Defining
sustainable
development
and
sustainability ................................................................ 29
3.2
Assessing the sustainability of bioenergy: An
integrated systems approach.....................................33
3.3
Biofuel sustainability initiatives: Certification and
standards ......................................................................40
3.4
Identifying the sustainability criteria and indicators
for bioethanol production ........................................47
4 Methodological approach ........................................................... 51
4.1
Defining life cycle assessment (LCA) .....................51
4.2
LCA as a tool for sustainability assessment ...........54
4.2.1 Defining net energy and greenhouse gas (GHG) balances 56
xv
Doc t oral Thes is / Dilip Khat iwa da
4.3
4.4
4.5
4.5.1
4.5.2
Realisation of a case study in Nepal: Sensitivity
analysis and development of scenarios ...................58
A review of regulatory schemes on accounting
lifecycle GHG emissions ..........................................64
Optimizing the ethanol industry: A systems
approach ......................................................................64
Complementarity of bioelectricity with hydroelectricity ...... 65
Techno-economic optimisation of sugarcane biorefineries ... 65
5 Assessing the sustainability of bioethanol production in Nepal 69
5.1
Lifecycle energy and GHG balances .......................69
5.2
Sensitivity analysis and scenario development ......72
5.2.1 Performance at the plant level ......................................... 73
5.2.2 Market impact on LCA allocation ratio for determining net
energy and GHG balance .............................................. 76
5.2.3 Agricultural practices and yield improvements ................. 77
5.3
International references on energy and GHG
balances of bioethanol production ..........................78
5.4
Immediate economic and environmental benefits,
and other sustainability aspects ................................ 81
6 Accounting GHG emissions in bioethanol production .............. 85
6.1
Estimates of lifecycle GHG emissions in regulatory
schemes ........................................................................85
6.2
Comparisons of the lifecycle emissions..................87
6.3
Major issues and concerns about GHG accounting
methodologies............................................................. 90
7 Developing the bioethanol industry in terms of energy security 93
7.1
Power generation from residual biomass: A
complementary option to hydroelectricity in Nepal
and Brazil .....................................................................93
7.2
Complementing hydroelectricity with bioelectricity
in terms of energy security........................................94
7.3
Realising the bioelectricity potential: A discussion97
7.4
Optimising sugarcane biorefineries for energy
production: A techno-economic analysis ...............99
7.4.1 Optimising energy production in the reference scenario .... 100
7.4.2 Determining the impact of key parameters: Scenario and
sensitivity analysis ........................................................ 101
8 Conclusions............................................................................... 105
8.1
Conclusions .............................................................. 105
8.2
Future work.............................................................. 108
9 References .................................................................................. 111
xvi
Sustainability of bioethanol production in different development contexts: A systems approach
Index of Figures
Figure 1: Global primary energy demand by fuel type in 2010 ...................2
Figure 2: Simplified layout of sugarcane bioenergy systems in Nepal and
Brazil ................................................................................................ 10
Figure 3: Layout of the thesis. ....................................................................... 14
Figure 4: Development of the thesis and appended papers. .................... 15
Figure 5: The trend in global bioethanol and biodiesel production, 2000 –
2011. ................................................................................................. 18
Figure 6: The production of biofuels from different biomass sources... 19
Figure 7: Production routes of bioethanol .................................................. 22
Figure 8: Evolution of global ethanol production by type of feedstocks.
............................................................................................................................ 23
Figure 9: Sugarcane biorefinery: different stages of production plant. ... 26
Figure 10: The three pillars of sustainability and their interaction in the
sustainable energy system ............................................................. 31
Figure 11: Life Cycle Assessment (LCA) Framework. .............................. 52
Figure 12: Integration of LCA and sustainability assessment. ................. 56
Figure 13: System boundary and material flows (per hectare) for
sugarcane-based systems in Nepal. ............................................. 61
Figure 14: (a-j) Realisation of the case study in Nepal: Sugarcane farming
and factory operations .................................................................. 63
Figure 15: A schematic diagram of the BeWhere model for sugarcane
biorefinery in Brazil....................................................................... 66
Figure 16: Size and location of existing sugarcane mills in the state of
Sao Paulo (SP). ............................................................................... 67
Figure 17: The contribution of fossil and renewable energy required to
produce 1 litre of EtOH (MOE) in Nepal, at each stage of the
ethanol production chain.............................................................. 70
Figure 18: Effect of different levels of energy consumption at the
ethanol plant on NEV values. ..................................................... 73
xvii
Doc t oral Thes is / Dilip Khat iwa da
Figure 19: Lifecycle GHG emissions: the case of treatment type (left)
and biogas leakage (right). ............................................................ 74
Figure 20: GHG emissions shares from different stages of the ethanol
production chain in Nepal (in the case of using surplus
electricity to substitute diesel). ..................................................... 76
Figure 21: Effect of changes in the price of molasses on NREV and the
energy yield ratio. ........................................................................... 77
Figure 22: Sensitivity analysis for lifecycle GHG emissions and avoided
emissions (%) as a function of different allocation ratios for
sugar and molasses. ....................................................................... 78
Figure 23: Sensitivity analysis for variations in material/energy inputs and
sugarcane yield in Nepal. .............................................................. 79
Figure 24: Well-to-wheel GHG emissions for sugarcane ethanol,
including credits from surplus electricity and mechanised
harvesting. ....................................................................................... 86
Figure 25: Lifecycle GHG emissions in different scenarios of the USEPA methodology (with and without residue collection and
CBI).................................................................................................. 88
Figure 26: Comparison of GHG emissions for sugarcane ethanol
according to four different regulations. ..................................... 89
Figure 27: Electricity generation in Brazil, by source 2000–2009............ 96
Figure 28: Trend of electricity consumption (residential & industrial)
with potential surplus bioelectricity during the sugarcane
crushing period (left) and imports of electricity and potential
surplus bioelectricity (right) in Nepal. ........................................ 97
Figure 29: Lifecycle costs (left) and emissions (right) along the biofuel
supply chain in the reference scenario...................................... 101
Figure 30: Impact on the type of substituted electricity; expressed in
emission factor (left) and investment cost (right) without
condition of export (i.e. at the low gasoline price in the EU).
........................................................................................................ 102
Figure 31: Impact of power plant efficiency ............................................. 103
Figure 32: Impact of biofuel support (left) and carbon tax (right). ....... 104
xviii
Sustainability of bioethanol production in different development contexts: A systems approach
I n d e x o f Ta b l e s
Table 1: Sustainability criteria/indicators for evaluating biofuel
production and use as a transport fuel .................................... 49
Table 2: Primary energy balance of sugar milling in Nepal (including
distillation, dehydration and ETP) ........................................... 71
Table 3: Lifecycle GHG (CO2eq) balance of molasses-based ethanol
(MOE, EtOH) fuel in Nepal..................................................... 72
Table 4: Surplus bioelectricity potential in Nepal and Brazil ................... 95
xix
Doc t oral Thes is / Dilip Khat iwa da
xx
Sustainability of bioethanol production in different development contexts: A systems approach
1 Introduction
This introductory chapter provides background information and motivation for
this dissertation on bioethanol production in different development contexts. The
objectives of the thesis, key research questions, a basis overview of the methodological approach, and the scope of the thesis work are given. Finally, the structure of the thesis is presented.
1.1 Background
The continuous depletion of fossil fuel reserves, the global agenda on
climate change and threats to energy security have led to increased global
interest in the exploration, production and utilisation of biofuels and bioenergy. Modern bioenergy includes versatile energy carriers such as liquid/gaseous biofuels, bioelectricity, and process heat, which are obtained
after the efficient conversion of biomass such as agricultural residues/wastes and lignocellulosic biomass. Bioenergy systems have been
drawn to the attention of policy makers around the world as they reduce
dependence on fossil fuel, contribute to sustainable rural development,
and are carbon-neutral. Reasons to promote biofuels include energy security, environmental concerns, foreign exchange savings and the socioeconomic well-being of rural dwellers (Demirbas, 2008). Rising oil prices
and energy security issues are the source of serious concerns in developing and least developed countries (LDCs) while climate change has led to
the development of a global agenda that is also promoting renewable energy (UNIDO, 2006).
Energy is crucial for the economic development of any nation. However, it should be sustainable, clean, renewable, and affordable. Fossil
fuels are the main dominating sources of global energy production
(IEA, 2012), contributing to more than 80% of global primary energy
(see Figure 1). The use of fossil fuels in transport and power plants has
not only significant environmental impacts due to the release of GHG
emissions and other air pollutants but it also contributes for the depletion of limited resources. In this context, renewable energy carriers such
as biofuels in transport and renewable electricity e.g. bio-electricity, micro-hydro power, wind and solar power off-grid and decentralised power systems for providing energy services in rural and isolated areas have
become increasingly attractive options. Besides, for a low-carbon and sustainable energy future, synergy should be developed between the use of re1
Doc t oral Thes is / Dilip Khat iwa da
newables and the adaptation of energy efficiency measures, also known as the
‘twin pillars’ (REN21, 2012).
Figure 1: Global primary energy demand by fuel
type in 2010.
Source: IEA (2012)
The share of renewables in global primary energy demand was 13% in
2010 with the main contribution from bioenergy (also, see Figure 1),
which accounted for 10% of global primary energy supply (IEA, 2012).
Most biomass is consumed in low-income and developing countries for
cooking and heating purposes using inefficient conversion techniques
such as open fires or simple cook-stoves. This has considerable impact
on health (i.e. indoor air or smoke pollution) and environment (i.e. deforestation and desertification). The contribution of modern bioenergy
supply is still relatively small but it has been growing gradually over the
last decade (IEA, 2012). The share of bioenergy (including traditional
biomass) has remained static since 2000 whereas the proportion of other renewable sources, i.e. wind and solar, has increased. It should be
noted that the contribution of traditional biomass as a proportion of the
of the total renewable energy decreased from 50% in 2000 to 45% in
2010, while transport biofuels met a growing share of transportation
fuel needs (IEA, 2012). Bioelectricity production provided 1.5% of electricity in 2010, while the share of liquid biofuels (bioethanol and biodiesel) in global road transport fuels accounted for around 3%, primarily in Brazil, US, and EU (IEA, 2012).
Despite the large proportion of bioenergy in the primary energy mix,
the majority of biomass is used very inefficiently. Modern bioenergy
services provide high quality energy carriers such as commercial biofuels and bioelectricity, which are more versatile and efficient than traditional usage. Therefore, the shift from the use of traditional biomass to
modern bioenergy services is essential for providing more commercial
energy products. Modern bioenergy/renewables can substitute fossil
2
Sustainability of bioethanol production in different development contexts: A systems approach
fuels in the transport and power sectors, providing a wide range of benefits, including energy security, rural development, reduction of GHG
emissions, reduced import dependency, job creation, biodiversity conservation, and energy access (REN21, 2012).
Billions of poor people in developing countries either rely on
dirty/polluting cooking fuels such as traditional biomass, charcoal, and
animal wastes or consume very low amount of energy, leading to a condition of energy poverty. In 2010, roughly 1.3 billion people lacked access to electricity and 2.6 billion people relied on traditional biomass for
cooking and heating (IEA, 2012) with the majority being the populations
in sub-Saharan Africa and other low-income countries/LDCs. Traditional biomass contributes 78.3% of the total energy in LDCs, while the figures for developing and OECD countries are 26.3% and 4.6% respectively (UNDP, 2006).
Several studies have been recently performed in order to assess biofuel
and bioenergy development in low-income countries in Africa in terms
of increasing energy security/energy access and reducing energy poverty,
which is required for socio-economic and sustainable development in the
continent (Batidzirai et al., 2006; UNDESA, 2007; FAO, 2010; Amigun
et al., 2011; Okello et al., 2013; Arndt and Benfica, 2011; Agbemabiese et
al., 2012; Sokona et al., 2012). The majority of African countries are net
oil importers (Amigun et al., 2011). Reducing reliance on oil imports is
important not only because of the huge economic burdens that lowincome countries are facing, but also because the utilisation of abundant
domestic renewable resources could help to drive development. Biofuels
can offer economic, social and environmental benefits if they are produced in a sustainable manner (Amigun et al., 2011).
The production and use of renewables is rapidly growing in many developing and developed countries. At the same time, several efforts have
been made to produce biofuels, which consider various sustainability assessment criteria and standards (Scarlat and Dallemand, 2011). Targets
and/or mandates have been put in place for bioenergy as part of many
national energy and climate policies, which consider that they contribute
towards enhancing energy security and climate change mitigation at the
national and regional level (IEA, 2012). Biofuels are considered an attractive alternative in transport as they can potentially reduce greenhouse gas
emissions, promote energy supply security and diversify energy services,
among other things. However, various concerns related to the environmental impacts of biofuels production have recently been identified,
which threatens the expansion of biofuel production. Debates surrounding the production of bioenergy mainly concern the competition between food and fuel, deforestation, soil erosion/degradation, air quality,
3
Doc t oral Thes is / Dilip Khat iwa da
water scarcity, loss of biodiversity, social imbalances, and destruction of
natural ecosystems services (Khatiwada, 2010; Scarlat and Dallemand,
2011; Diaz-Chavez, 2011; Buytaert et al., 2011).
Nevertheless, in many developing countries, bioenergy could offer numerous benefits such as the utilisation of domestically available resources, employment generation, energy security/diversity, climate
change mitigation, and low-carbon green economic development when
traditional biomass is efficiently transformed into modern energy carriers, viz. heat, power, and biofuels, through technological advancement
and commercial investment (Owen et al., 2013). Biofuels could contribute significantly towards sustainable development if produced according
to sustainability criteria defined in the EU-Renewable Energy Directive
(RED). But, the RED policy may not be directly applied to low-income
countries. Lucia (2010) has examined how the EU policy ‘Renewable
Energy Directive (RED)’ and its sustainability certification system can effectively ensure the sustainable production of biofuels outside the EU,
by considering the case of a least developed country (LDC) with high
biofuel ambitions. Common mutual interests (e.g. food security and land
competition), development assistance, international policy legitimacy,
networking and the involvement of foreign actors would be crucial for
cooperation to develop sustainable biofuels. It should be noted, however, that climate and biodiversity issues in the EU policy are not well
matched with the interests of the LDCs (Lucia, 2010). Nevertheless, we
should not miss this window of opportunity as biofuels could expand to
meet domestic demand in the short-term and have prospects for further
expansion through international trade.
Bioenergy/biofuels conversion systems can be developed for providing
more modern commercial fuels, thus contributing towards energy supply
security. The concept of energy security is progressing differently across
the globe. Energy security is ‘the continuity of energy supplies relative to demand’,
Winzer (2012). The International Energy Agency (IEA) defines ‘energy
security’ as ‘the uninterrupted physical availability at a price which is affordable,
while respecting environment concerns’. It has two main aspects: managing the
supply and demand of energy needs (i.e. short-term energy security), and
securing long-term investment for the energy infrastructure required for
sustainable and environmentally responsible economic development.
Kruyt et al. (2009) distinguished energy security in four dimensions, viz.
availability, accessibility, affordability and acceptability of energy. Kruyt
et al. (2009) also classified simple and aggregated indicators for energy
security, including resource estimates, reserve to production ratios, diversity indices, import dependence, political stability, energy price, market
liquidity, and willingness to pay. The selection of specific indicators is
difficult and issues of energy security are highly context dependent
4
Sustainability of bioethanol production in different development contexts: A systems approach
(Kruyt et al., 2009). In developing countries, energy poverty is a great
threat to sustainable development and the improved livelihoods of people (UNEP, 2011a). Besides, the availability of clean, affordable, reliable
and sustainable energy is important in order to meet development objectives of developing countries. The introduction of modern bioenergy
services such as biogas, liquid biofuels, and bioelectricity could help to
eliminate energy poverty. Similarly, diversification of energy systems and
efficiency improvements could help to improve energy security.
Bioethanol already contributes a significant proportion of the total biofuel market in the world, and its production could be significantly increased, particularly in sugar producing countries, where it can be used to
replace fossil fuels (Balat et al., 2008; Balat and Balat, 2009; REN21,
2012). However, as previously mentioned, the production of biofuels has
become controversial on sustainability grounds. This thesis explores the
sustainability aspects of biofuel production in two specific countries,
Nepal and Brazil, in terms of economic development, natural environment, and geopolitical conditions. Is bioethanol production sustainable
in low-income countries? What are the energy and climate gains of bioethanol production and use? How can we develop the bioethanol industry to promote the security of energy supply?
1.2 Objective and research questions
The main objective of this thesis is to assess the sustainability of bioethanol production in different development contexts, particularly observing environmental constraints.
The thesis is focused on the following key research questions:

What affects the sustainability of bioethanol production?

How can the sustainability of bioethanol be calculated in
terms of lifecycle GHG emissions?

What are the benefits of developing the bioethanol industry
in terms of energy security?
The first question involves identifying the key parameters in affecting the
sustainability of bioethanol production and use in the transport sector in
the case of a low-income country. The second question is related to the
evaluation of methodologies for accounting lifecycle GHG emissions,
which is one of the key sustainability assessment criteria presently being
applied by most countries. The third is concerned with the immediate
benefits of developing the bioethanol industry in terms of energy security. Addressing these questions, the study performs a case study on the
5
Doc t oral Thes is / Dilip Khat iwa da
sustainability assessment of bioethanol production and use in Nepal. The
thesis also conducts a methodological study for estimating the GHG balance of Brazilian sugarcane ethanol in different biofuels regulations.
Analyses of the technological improvements of conventional sugarcane
mills or bio-refineries for the production of bioelectricity and/or second
generation ethanol are performed, considering the optimum utilisation of
resources.
The key research questions are addressed in the following steps:
1.
Examination of the net energy balance, lifecycle greenhouse
gas (GHG) emissions, and prospects for sustainable development and climate change mitigation in the production
and use of bioethanol in a low-income country
2.
Evaluation of methodologies developed for the sustainability assessment of bioethanol production
3.
Investigation of the synergetic effect and techno-economic
performance of the bioethanol industry
1.3 Development of case studies in Nepal
and Brazil
This dissertation focuses on the energy and climate aspects of the bioethanol industry in Nepal and Brazil. The production and use of modern
bioenergy services varies significantly in different regions. Furthermore,
the scope and extent of sustainability assessment varies within the context of individual countries (also, see Chapter 3). A number of tropical
developing countries such as Brazil, Malaysia, and Indonesia are interested in the large-scale production of biofuels, aimed at the international
biofuel trade. Therefore, compliance with international biofuel or renewable policy, such as Renewable Energy Directive (RED), Renewable Fuel
Standard (RFS), and Low Carbon Fuel Standard (LCFS) is of vital importance. On the other hand, in low-income and LDCs, such as Nepal
and countries in sub-Saharan regions, the biofuel industry is still in its infancy, and therefore does not have immediate opportunity for the largescale commercial production of biofuels and trade. Instead, small-scale
production of biofuels can be developed using locally available biomass
resources for providing security of energy supply. The issues therefore
differ between countries. With this in mind, it is necessary to analyse biofuel development by considering the various benefits from multiple perspectives, including food security/prices, climate change impacts, and
land use change, etc.
6
Sustainability of bioethanol production in different development contexts: A systems approach
Nepal is a least developed and landlocked country in South Asia with
more than 80% of the total population living in rural areas. Nepal’s total
primary energy supply (TPES) system is dominated by the use of traditional biomass (87%), followed by fossil fuels (10%), hydroelectricity
(2%), and renewable sources (less than 1%) (WECS, 2010). The country
does not have fossil fuel reserves. The transport sector is the largest consumer of imported petroleum products. Vehicular emissions are a major
source of air pollution in the capital city, Kathmandu valley, which alone
consumes 70% of the total imported gasoline. The accumulation of foreign debts for oil imports, rising costs, the frequent shortage of transport
fuels, public unrest due to rises in the subsidised price of petroleum
products, and alarming air pollution have contributed to discussions
concerning alternative sources of transport fuel in the Kathmandu Valley. Increasing foreign debts have also put pressure on the national
economy as they divert money away from the scarce developmental
budget of the country. In 2004, the Government of Nepal (GoN) decided to blend 10% ethanol with gasoline and, in 2008, a high level committee with the task of finding energy alternatives to reduce oil consumption
was formed. However, the potential of ethanol production has not yet
been realised due to conflicting economic, technical and political issues,
and a lack of trust amongst major stakeholders. Meanwhile, only 56% of
the population has access to electricity in the country (UNDP, 2011) and
regular power-outages (load-shedding) have also negatively impacted on
industrial and socio-economic development.
Brazil is one of the fastest-growing middle-income developing countries
in terms of economic growth and industrialisation. Brazil is highly urbanised with more than 80% of the population living in urban areas. In the
Brazilian primary energy matrix, renewable energy sources have a significant share - 46.9% compared with 6.1% on average for OECD countries
and 13.2% in the world as a whole. In 2010, sugarcane-related products
accounted for 18.8% of Brazil’s primary energy, hydropower for 13.9%,
and firewood 10.2% (MME, 2010). The share of traditional firewood (i.e.
10.2%) has decreased significantly in past decades as a result of modernisation in the Brazilian economy. The share of firewood in the Brazilian
energy matrix was 45% in 1970. Today, 90% of the Brazilian energy matrix comprises commercial energy. In contrast, Nepal only utilises 12%
of commercial energy with the remainder derived from traditional biomass. A similar situation is found in other LDCs. The large use of energy in the industrial sector, together with the commercial character of the
energy sector, provide evidence for the high level of industrialisation already reached in Brazil. It should be noted that Brazil has managed to
achieve significant success in terms of economic development, equity
and social justice, reductions in poverty and inequality, and in extending
7
Doc t oral Thes is / Dilip Khat iwa da
basic services. The country has abundant potential for biofuel production, use and trade.
LDCs have not yet harnessed their huge potential for producing ethanol
from sugarcane systems. However, in recent years, they have been showing interest in the development and deployment of sugarcane bioenergy
in an effort to reduce dependence on imported fuels and enhance domestic energy security, as is the case in Nepal. Both the private and public sectors are willing to promote this commercial biofuel. International
cooperation on the climate change agenda could help to initiate work in
sustainable sugarcane bioenergy systems in LDCs, such as is being tried
in the Bioenergy and Food Security (BEFS) program in Tanzania (FAO,
2010). Versteeg (2007) has evaluated the environmental sustainability of
sugarcane-bioethanol production in Fiji, a small island developing state
in the Pacific, estimating reductions in life cycle GHG emissions, net energy balances, and ecological footprints in the context of sustainable development. The feasibility study focused on how to select LDCs to produce bioethanol in an effective and sustainable way, indicating that surplus cane sugar, dependency on imported fuels, and economic production potential are the key selection criteria (DSD, 2005). However, detailed analyses of the production of bioethanol have not been carried out
for LDCs in general and Nepal in particular. This study partly aims to
make a contribution to help fill this void in knowledge, with an analysis
of the case of Nepal using a life cycle perspective.
There are a plethora of studies on the sustainability assessment of sugarcane bioenergy systems in Brazil, which encompasses the life cycle analyses, including socio-economic and environmental impacts (e.g. Smeets
et al., 2006/2008; Macedo et al., 2008; Goldemberg et al., 2008; Seabra et
al., 2011). Biofuels industries are growing steadily in developing and developed countries, and the concept of biorefinery (analogous to oilrefinery) has also been emerging for producing multiple energy and nonenergy products (e.g. bioelectricity, second generation ethanol and bioproducts) from various feedstocks such as agricultural and forest residual
biomass. Additionally, research and development are currently being
conducted into the expansion of second generation (2G) liquid fuel production from cellulosic bioenergy feedstock in the US, EU and Brazil.
These 2G biofuels are believed to be more sustainable as their production does not complete with food and feed production when agricultural
and forestry bio-products/wastes are used as the feedstock. However,
there are also challenges in the supply-chain and logistics management.
Product diversification at agro-industry based biorefinery, the supply of
renewables, viz. bioethanol and bioelectricity, the development of infrastructure, job creation in rural areas, and the conversion of low-value biomass into high-value products and carbon gains are main factors be8
Sustainability of bioethanol production in different development contexts: A systems approach
hind the promotion of biorefineries. The introduction of the bio-based
or green economy concept for sustainable development has also further
motivated the development of sustainable biofuels. Some systems optimisation studies have been recently conducted to analyse the technoeconomic and environmental performance of biofuels production, use
and international trade, considering different feedstock, spatial location,
and technological choices (e.g. Leduc, 2009; Wetterlund et al., 2012;
Leduc et al., 2012). This dissertation also conducts resource and systems
optimisation studies, considering the case of the Brazilian sugarcane ethanol industry.
This thesis uses the concept of sustainable development and sustainability to analyse one of the potential energy crops sugarcane derived ethanol
production in Nepal and Brazil. The case study on Nepal provides a
more macro view of a biofuel sustainability assessment. Systems approaches on assessing the sustainability and life cycle assessment (LCA)
of biofuels provide the methodological framework for the study. Assessment of the biofuels (molasses-bioethanol) sustainability in Nepal is
the first of its kind in low-income countries, but also serves the purpose
of motivating the assessment of ethanol production potential in other
LDCs, particularly in sub-Saharan Africa. Biofuels should meet both
GHG and other sustainability standards in order to be considered a
commodity for international trade. The study on Brazilian sugarcane ethanol in particular describes the methodological studies on accounting for
the most significant sustainability criteria i.e. GHG emissions, considering European and US regulatory schemes, whilst also reflecting the need
of further attention for other biofuel pathways. The cases of Nepal and
Brazil in the thesis attempts to find the synergetic benefits of developing
the bioethanol industry in terms of energy security.
The intended audiences of this thesis are policy makers, private investors, researchers, and other stakeholders (e.g. donor agencies and development partners) who are interested and motivated enough to consider
making concerted and unified efforts towards the production of sustainable biofuels in low-income, developing and developed countries. The
insights provided in the thesis could help national/regional governments
and international development organisations accelerate the development
agenda on the promotion of modern bioenergy services needed for the
transition to a low-carbon development path.
1.4 Scope of the thesis
The thesis investigates the sustainability of bioethanol production from
the sugarcane energy crops, in two distinct development contexts i.e.
Nepal and Brazil, in terms of geopolitical location, economic develop9
Doc t oral Thes is / Dilip Khat iwa da
ment and state-of-art technologies in agro-industrial development. Nepal is a low-income/least developed country in Asia whereas Brazil is a
rapidly growing developing country in South America. Both countries
are sugarcane producers. Brazil is the largest producer of sugarcane in
the world and the second largest producer of ethanol. Nepal is a sugar
producer and has the potential to produce ethanol using sugarcane molasses. Figure 2 provides a simplified schematic diagram of the sugarcane
energy systems in Nepal and Brazil.
Figure 2: Simplified layout of sugarcane bioenergy systems in Nepal and Brazil.
Note: Cane juice-ethanol, ferti-irrigation, excess bioelectricity to the grid system in Brazil (see
dotted line) while Molasses-ethanol and spent wash to biogas conversion in Nepal (see red
line)
Brazil is the largest exporter of bioethanol in the world. Developed
countries e.g. US and Europe have set sustainability criteria for biofuels
especially related to climate change impacts. It is necessary to meet the
defined criteria for the import of the ethanol in the regions. This study
investigates the methodologies for accounting GHG emissions from
Brazilian sugarcane ethanol and the implications in terms of results.
The study also explores the benefits of developing sugarcane mills as biorefinery for producing energy services and thereby utilizing the available biomass more efficiently. The entire production chain of sugarcane
systems including the use of co-products or by-products such as residual
biomass (i.e. bagasse and trash/waste) and molasses for energy production are considered in the study. Sugarcane molasses can be used for the
production of ethanol where there is a high demand for sugar, such as in
Nepal. While, sugarcane juice is used for the production of ethanol
10
Sustainability of bioethanol production in different development contexts: A systems approach
where there is surplus sugarcane feedstock for sugar production, such as
in Brazil. The sugarcane bioenergy systems in Nepal and Brazil are presented in Chapter 2 and Chapter 4.
The thesis considers systems approaches, viz. life cycle assessment
(LCA) and energy system modelling in analysing sugarcane bioenergy
systems for the production of bioethanol. Energy and greenhouse gas
(GHG) balances have been evaluated considering the whole lifecycle energy, emissions, and material flows in producing bioethanol from sugarcane molasses in Nepal (Paper I and II). This covers local agricultural
practices, the harvesting of sugarcane, cane milling, and the ethanol conversion phase, through the fermentation, distillation and dehydration
route, and waste management. The socio-economic and environmental
benefits of producing ethanol in Nepal are presented in Paper III. Critical examination of lifecycle GHG accounting methodologies in regulatory schemes designed in relation to the Brazilian sugarcane ethanol is performed (Paper IV). Accounting GHG emissions for measuring climate
change impact is increasingly becoming an important criterion when it
comes to the expansion of bioethanol production and international
trade. Surplus sugarcane biomass can be used to produce bioelectricity if
combusted in the efficient cogeneration plant. Complementarity of producing bioelectricity with hydropower using surplus sugarcane biomass
in efficient plants in both Nepal and Brazil is presented in Paper V. Finally, a techno-economic optimisation study on the up-grading of sugarcane mills for the production of second generation bioethanol and/or
production of bioelectricity is carried out in Paper VI, considering the
lifecycle costs and emissions for the two advanced technological options.
The thesis reflects a trend towards the modernisation of sugarcane mills
for producing more reliable energy services without compromising the
need for food or sugar production. An underlying purpose is to contribute to an increased knowledge base on how local biomass resource can
be transformed into modern commercial energy products (i.e. liquid fuel
and electricity) in an effective and efficient manner, considering energy
and climate change policies (i.e. climate change mitigation and energy
security) in the two development contexts having different stages of
technological and economic development. The effect of indirect land
use change (iLUC) and the optimisation analysis of individual sugarcane
mills at the plant level is not in the scope of this thesis.
The key research objectives and questions are sub-divided into specific
objectives and research questions, which are individually dealt with in
the six appended papers. These are briefly introduced below.
Sustainability of bioethanol production in Nepal
11
Doc t oral Thes is / Dilip Khat iwa da
Paper I and II evaluate the lifecycle energy and GHG balances of molasses based ethanol in Nepal, one of the low-income/LDCs in Asia.
The energy balances/energy yield ratio and net GHG emissions are calculated. In Paper III, the socio-economic and environmental performance of bioethanol production and its use are analysed. The potential
for the substitution of fossil fuels and the mitigation of greenhouse gas
emissions are investigated. Economic opportunities and direct environmental and health impacts are also explored. The main questions in the
investigation are:
i.
Is bioethanol production sustainable in terms of net energy and
GHG balances?
ii.
What are the direct benefits of bioethanol substitution in the
transport sector?
Accounting GHG emissions in bioethanol production
Paper IV analyses the methodological issues for accounting the lifecycle
GHG emissions of Brazilian sugarcane ethanol in different European
and American regulatory schemes. The study aims to identify a common
ground for the development of a unified methodology for sugarcane
ethanol. The main question in the investigation is:
iii.
What are the methodological issues in estimating GHG balances for
sugarcane bioethanol?
Developing the bioethanol industry in terms of energy security
Paper V investigates the complementarity between hydroelectricity and
bioelectricity from sugarcane biomass-based cogeneration plants in sugarcane mills in Nepal and Brazil when the surplus sugarcane biomass is
efficiently utilised. The study deals with the benefits of developing the
bioethanol industry in terms of security of electricity supply. This comparative study also offers a reflection on regulatory and institutional aspects for the development of bioelectricity in the two countries. Paper
VI investigates the alternative uses of sugarcane biomass for second
generation ethanol and/or bioelectricity production in Brazil, assuming
the technological improvement of existing mills. A mixed integer linear
program (MILP), the BeWhere, is used to optimise the choice of technology for producing energy products and services in sugarcane biorefineries. The entire supply chain of the electricity and biofuel production
is considered in the techno-economic optimisation analysis. The main
questions in the investigation are:
12
Sustainability of bioethanol production in different development contexts: A systems approach
iv.
How would power generation from sugarcane biomass complement
electricity demand?
v.
What could be suitable technological choices when upgrading sugarcane mills for producing second generation bioethanol and/or bioelectricity from residual biomass?
1.5 Outline of the thesis
This PhD thesis is divided into four blocks and includes eight chapters.
The layout and flow of the thesis is presented in Figure 3. Block one
comprises of Chapter 1 and 2. Chapter 1 begins with an introduction,
background and motivation of the research. This chapter also presents
the main research questions and scope of the thesis. In Chapter 2, an
overview of biofuels production, conversion technologies, bioethanol as
a transport fuel, and the concept of sugarcane biorefinery are presented.
Theoretical framework and methodologies are presented in the second
block, i.e. Chapter 3 and 4. Chapter 3 contains the conceptual frameworks on sustainability assessment while Chapter 4 presents the methodological approaches used in this research and particularly in the appended papers.
The third block is the main body of the thesis which contains major discussions and findings of the dissertation. Chapter 5 begins with a discussion on key parameters influencing the sustainability of bioethanol production in a low-income country, Nepal. Methodological issues for accounting GHG emissions of sugarcane bioethanol are discussed in
Chapter 6. The importance of the technological improvements at sugarcane mills for the production of more energy services which help to
promote the security of energy supply are explained in Chapter 7, which
justifies the benefits of developing the bioethanol industry. In the fourth
block, i.e. Chapter 8 presents the conclusions of the thesis and outlines
the need for future work.
13
Doc t oral Thes is / Dilip Khat iwa da
Figure 3: Layout of the thesis.
Figure 4 describes the development of the thesis work including appended research papers, which corresponds to the three main research questions and respective thesis objectives. It is indispensable to consider the
sustainability and synergy dimensions together in a systems approach
while developing the ethanol industry in consideration of climate change
mitigation, sustainable development, and energy security. This dissertation explores the question whether bioethanol production is sustainable
and whether synergic benefits can be accrued in different development
contexts.
14
Sustainability of bioethanol production in different development contexts: A systems approach
Figure 4: Development of the thesis and appended papers.
15
Doc t oral Thes is / Dilip Khat iwa da
16
Sustainability of bioethanol production in different development contexts: A systems approach
2 State-of-the-ar t systems
in biofuel production
In this chapter, the state of the art in biofuel production is presented starting
with an overview of biomass resources/feedstocks and the conversion technologies
used to produce liquid biofuels, followed by the use of bioethanol as a transport
fuel and the introduction of the concept of biorefinery for producing modern bioenergy services.
2.1 Bioenergy and biofuels: An overview
Bioenergy is obtained from biomass, in the form of different solid, liquid
or gaseous fuels. Biomass is not only a source of food, fibre, and fodder, but
also the world’s fourth largest source of energy, following the increasing scarcity
of non-renewable fossil derivatives: oil, coal and natural gas. The demand for
biomass as a renewable fuel is increasing rapidly. Of the total global biomass
consumption, it is estimated that 86%, mostly in the traditional form (i.e. directly burned in inefficient devices), is used for heating/cooling purposes, and for
industrial applications. Meanwhile, 10% biomass is used in CHP (combined
heat and power) and electricity power plants, and the remainder is used to produce liquid biofuels for road transport (REN21, 2012). Food crops (sugarcane, corn, soybean, wheat, and sugar beet), hydrocarbon-rich plants,
waste (crop, food, and municipal), weeds and wild growth, and lignocellulosic biomass are the potential sources of biomass for bioenergy generation (Abbasi and Abbasi, 2010). Ethanol and biodiesel are the main renewable transport fuels. The production of these renewable fuels has rapidly increased over the past five years, with an average annual increase of 17% for
ethanol and 27% for biodiesel (see Figure 5). Biodiesel is obtained through
the esterification of plant oils, whereas bioethanol is mainly derived from
agricultural feedstocks. The use of biofuels in the transport and industrial
sectors is increasing due to growing concerns about fossil-fuel reserves,
climate change and sustainable development. Liquid biofuels, namely biodiesel and bioethanol, are used in their pure or blended form (with
conventional gasoline or diesel) in automobiles.
17
Doc t oral Thes is / Dilip Khat iwa da
F i g u r e 5 : The trend in global bioethanol and biodiesel production,
2000 – 2011.
Source: REN21, (2012)
There are many different routes for the conversion of biomass into modern bioenergy and biofuels, generating multiple energy carriers/services such as liquid
or gaseous biofuels, bioelectricity, and process heat. Biofuels from biomass
are obtained primarily through two production processes: bio-chemical
and thermo-chemical; bio-chemical processes may be further broken
down into chemical and biological conversion technologies (Demirbas,
2007; Abbasi and Abbasi, 2010; Sheehan, 2009; Walter and Ensinas,
2010; Menon and Rao, 2012). With the thermo-chemical route, biomass is
heated in the absence (or regulated/controlled concentration) of oxygen,
which includes pyrolysis, gasification, and Fischer-Tropsch processes.
The Bio-chemical route consists of five alternatives - fermentation, esterification, anaerobic digestion, photosynthetic organisms, and dark fermentation (Abbasi and Abbasi, 2010). Fermentation and esterification
produce bioethanol and biodiesel respectively whilst anaerobic digestion
creates biogas. Photosynthetic organisms and dark fermentation are part
of the experimental phase.
Fermentation and anaerobic digestion are classified as biological processes, whereas trans-esterification and hydro-treating follow chemical
processes, in terms of bioenergy conversion technologies, as shown in
Figure 6. The advantage of the thermo-chemical process is that it converts almost all of the organic components of the biomass into bioenergy, whereas bio-chemical processes only utilise the polysaccharide content of the biomass. Operation and maintenance costs are relatively high
in the thermo-chemical conversion, and these processes usually consume
significant amounts of fossil fuel along the production chain (Abbasi and
Abbasi, 2010).
18
Sustainability of bioethanol production in different development contexts: A systems approach
Figure 6: The production of biofuels from different biomass sources.
(Includes first, second and third generation biofuels)
Adopted from Sheehan (2009); also presented in Khatiwada et al.
(2010)
Biofuels are broadly divided into several categories, depending upon
feedstock characteristics and production pathways. In addition, bioenergy technologies are characterised according to the source and type of biomass, the characteristic of feedstock, the conversion process and the final energy carrier (IPCC, 2011). Several studies provide reviews of the
biofuel technologies used globally (IEA, 2004; Faaij, 2006; Demirbas,
2007; Royal Society, 2008; Nigam and Singh, 2011; Yan and Lin, 2009;
Naik et al., 2010; Menon and Rao, 2012). First generation biofuel technologies are well established, and include the fermentation of sugars and
starches and the trans-esterification of plant oils. For example, cereals,
grains and sugar crops can be fermented to produce bioethanol, while
oilseed crops such as sunflower, rape-seed, soybean, palm and jatropha
can be converted to methyl esters (biodiesel). However, first generation
biofuels are being debated due to concerns over land use, food security/prices, water scarcity, and deforestation. Second generation biofuel
conversion technologies are complex, expensive and at an early stage of
research & development and commercialisation. They are obtained from,
among other things, lignocellulose (cellulose, hemicelluloses, and lignin –
e.g. woodchips, straw and, cane bagasse) feedstocks, through a conversion route that includes acid hydrolysis, followed by enzymatic fermentation.
19
Doc t oral Thes is / Dilip Khat iwa da
Second generation biofuels, produced from agricultural and forestry residues, municipal solid waste, and other forms of lignocellulosic biomass,
can improve energy security, and reduce urban air pollution (Wyman,
1994) despite increased concerns about changes in land use patterns
(Brennan and Ownede, 2010). Third generation biofuels, derived from
microalgae, could avoid land use changes since they can be grown in
aquatic media i.e. water-surfaces (Brennan and Ownede, 2010; Goh and
Lee, 2010). Alam et al. (2012) have also presented the current status of
biofuel derived from algae. New research has been initiated in the development of genetically modified crops/plants, and novel biofuels from
non-food oil crops.
At present, commercial biofuels are mainly derived from energy crops
(e.g. sugarcane, corn) and oil feedstocks (e.g. palm oil, oilseed rape). The
production of biofuels has increased significantly in the past decade
(REN21, 2012). The reduction of greenhouse gas (GHG) emissions, the
diversification of commercial energy systems, and rural development are
a few motivating factors in terms of encouraging biofuel production.
Furthermore, biofuels can help to promote energy security, reduce the
environmental impacts arising from the transport sector, and create a
conducive environment for economic growth in rural areas and the industrial sector at large. Nigam and Singh (2011) have highlighted energy
security, economic stability and environmental gains as the main advantages of using biofuels. The key drivers of biofuel development in
Asia are: (a) the security of the energy supply chain, (b) climate change,
(c) land use changes and food security, and (d) rural development and
poverty alleviation (Yan and Lin, 2009). Zhou and Thomson (2009) have
also mentioned energy security, trade balances, foreign exchange, reduction in government expenditure, new markets for the principal agricultural products, employment in the agricultural sector, and climate change
as being the driving forces, while deforestation, problems with water security, the danger of monoculture, biofuels and food prices are highlighted as some of the negative impacts of biofuels production in Asia. Escobar et al. (2009) have assessed issues relating to environment, technology
and the food security of biofuels. Debates surrounding the production of
biofuel using the same raw materials for both fuel and food production,
and changing land use patterns have encouraged the assessment of the
sustainability of biofuels. Chapter 3 describes the sustainability framework for biofuel production.
2.2 Biofuel production
The production and use of biofuels is rapidly increasing, providing a
share of 3% of road transport fuel in 2010 (IEA, 2012). The focus of
biofuel production is largely limited in Brazil, US and EU. Bioethanol
20
Sustainability of bioethanol production in different development contexts: A systems approach
contributed more than 80% of the total liquid biofuel consumption in
the world in 2010 (REN21, 2012). Government rules and mandates such
as the Renewable Fuel Standard (RFS) in the US, the Renewable Energy
Directive (RED) in the EU, and other national governments initiatives
have opened the expanded demand of the biofuels across the globe. In
Europe, the EU-RED of 2009 set mandatory targets of a 10% share of
renewable transport fuel (mainly biofuels) by 2020 and 6% reduction in
GHG emissions. In the US, the Energy Independence and Security Act
(EISA) of 2007 also set renewable fuel targets of 36 billion gallons (15
billion gallons ethanol and 21 billion gallons of advance biofuel) by 2022.
Sorda et al. (2010) have presented an overview of biofuel polices across
the world, including blending targets, support schemes, and feedstock
use. In addition, many efforts have been made in formulating the regulatory and sustainability certification schemes of biofuels (see Chapter 3).
Figure 7 shows different routes for the bioethanol production process.
As can be seen in the figure, sugar/starch obtained from sugarcane/corn
or cellulose feedstocks follows the process of fermentation, distillation,
and dehydration in order to produce first and second generation ethanol
respectively. It should be noted that molasses (also a sugar-based product) is treated separately in the figure in order to distinguish it from other
conversion routes since this thesis considers molasses-based bioethanol
in the case of a low-income country, Nepal.
First generation bioethanol, obtained from sugarcane and corn feedstocks has so far dominated the bioethanol market globally and other
technologies are at an early stage of development. The United States
(US) was the world largest producer of bioethanol, accounting for about
56% (i.e. 49.2 billion litres) of the total bioethanol production (i.e. 87 billion litres) in 2010. Brazil was the largest bioethanol exporter and second
largest producer with a share of 30% (26.2 billion litres) whereas the EU
produced 4.6 billion litres (5.3%). The emerging developing country in
Asia – China contributed 2.4% while the rest of Asia only accounted for
2.3% of the total bioethanol production. The IEA ‘Biofuels for
Transport’ roadmap projected that biofuels could provide 27% of total
transport fuels by 2050 (IEA, 2011). The primary feedstocks for bioethanol production are corn (US), sugarcane and derived co-product molasses (Brazil, Thailand, India, Australia), and beet/grain (EU). The share of
cane and molasses was about 33% (cane: 29%, molasses: 4%) in an average of the last three years while coarse grains contributed 51%. The evolution of global ethanol production by feedstocks is shown in Figure 8,
which shows that coarse grains (e.g. corn) and sugarcane would remain
the main feedstocks for the bioethanol production until 2020 (OECDFAO, 2011). It should be noted that the share of ethanol from lignocellulosic biomass, waste material or non-food feedstocks would be still less
21
Doc t oral Thes is / Dilip Khat iwa da
than 7% in 2020. Different bioethanol production processes are discussed by various authors in the literature (IEA, 2004; Cardona and
Sanchez, 2007; Kumar et al., 2010, Abbasi and Abbasi, 2010; Najafi et
al., 2009; Nigam and Singh, 2011). Ethanol from sugarcane has proven
to be the most cost competitive over the last few decades, following a
steep learning curve in the production of ethanol (Goldemberg et al.,
2004; van den Wall Bake et al., 2009), and there is a strong global ethanol
market for international development (Hira, 2011). Additionally, the
production and trade of biofuels would become significantly important
if we consider the production of biomass feedstock in the high
productivity area and consumption in the regions with a high demand
for biofuels (IEA, 2011).
Figure 7: Production routes of bioethanol.
Adopted from Pennington (2009) with the inclusion of sugarcane by-products (molasses and bagasse), which is also cited by Abbasi and Abbasi (2010); also presented in Khatiwada et al. (2010).
Besides producing bioethanol from sugarcane juice, as in Brazil, other
developing countries such as Thailand and India are also producing bioethanol using a by-product of the sugar industry– molasses. Few studies
have been conducted into molasses-based bioethanol (Nguyen and
Gheewala, 2008a/b; Nguyen et al., 2008; Harijan et al., 2009; Prakash et
al., 1998; Kumar et al., 2010; Khatiwada and Silveira, 2009). Molasses
(with a fermentable sugar content of 40 – 45 % by weight, w/w) is the
by-product obtained during the crystallisation and centrifugation process
22
Sustainability of bioethanol production in different development contexts: A systems approach
in the production of sugar at a point when the extraction of sugar is no
longer possible. It is considered to be one of the potential sources of bioethanol production (Amigun et al., 2011; Harijan et al., 2009; Batidzirai
et al., 2006) in many sugar producing countries, including sub-Saharan
Africa and other low-income and developing countries. For example,
Mozambique could extract 68 million litres of bioethanol from sugarcane
by 2010 (Batidzirai et al., 2006). Nepal also has a sugar-molasses bioethanol production potential of 18 million litres per year (Silveira and
Khatiwada, 2010). India could produce an abundant amount of bioethanol from its available molasses (Kumar et al., 2010). However, policy
needs to be focused on the development and use of bioethanol in order
to realise such potential (Pohit et al., 2009).
In recent years, there have been a number of concerns with regard to the
environmental, social and economic sustainability of bioethanol production. This thesis deals with the sustainability aspects of sugarcane bioethanol taking the cases of sugar-producing countries. Chapter 3 provides
more details about the sustainability issues related to bioethanol production.
Figure 8: Evolution of global ethanol production by
type of feedstocks.
Source: OECD-FAO (2011)
2.3 Bioethanol as a transport fuel
Bioethanol is the most commonly used liquid biofuel in the transportation sector, especially in Brazil and the US, and its global use is growing
rapidly due to increased interest in both developed and developing coun23
Doc t oral Thes is / Dilip Khat iwa da
tries. Pharmaceutical, cosmetic and beverage items are also obtained
from the use of bioethanol. Thus bioethanol is not limited to the
transport sector (EUBIA, 2005). However, the largest share of bioethanol (more than 80%) has been used to fuel automobiles (IEA, 2004).
Vehicles can be fuelled either by pure or neat hydrous bioethanol (i.e.
95% ethanol v/v) or by a blend of gasoline and anhydrous (i.e. 99.5%
v/v) ethanol – the most common blend ranges from 5-25% (Costa and
Sodre, 2010). It has been found that bioethanol as a fuel additive improves engine performance and reduces exhaust emissions in addition to
increasing braking power and thermal and volumetric efficiency (AlHasan, 2003). Niven (2005) has examined five important environment
impacts of the ethanol enrichment of unleaded gasoline, viz. air pollution, subsurface contaminations, greenhouse emissions, energy efficiency, and sustainability. Automobiles with 5-10 % ethanol blended fuels do
not require any engine adjustments or modifications while minor modifications are needed for a 10-25 % ethanol blend (IEA, 2004).
Rising international oil prices, limited fossil-fuel reserves, environmental
and climate change concerns, energy security, and the diversity of energy
sources are the major driving forces behind the desire for developed
countries to produce biofuels. Biofuels may also help to save foreign currency, improve access to commercial energy, and generate local employment. However, the biofuel agenda has not yet had any major impacts in
the LDCs. One important reason is that development donors have not
prioritised bioethanol production. In addition, proper government policies are still lacking, even though there is great potential for bioethanol
production.
At the same time, there is increased apprehension about energy security
and climate change in both developing and developed countries. Biofuels
could contribute towards the mitigation of greenhouse gas emissions
while also promoting development. Energy security concerns and climate
threats for the least developed and land-locked countries are extremely
high as they are too weak economically to invest in new domestic technologies, require agricultural land for their growing populations in order
to produce food, and cannot afford imported fossil fuels.
2.4 Biorefinery and sugarcane bioenergy
systems
Biorefinery is an integrated process in which biomass feedstocks are
converted into a wide range of useful bioproducts/chemicals (e.g. food,
feed, materials) and modern forms of bioenergy (e.g. biofuels, bioelectricity and heat) in a sustainable manner (Ragauskas et al., 2006; NREL,
24
Sustainability of bioethanol production in different development contexts: A systems approach
2009; IEA Bioenergy, 2010). Ragauskas et al. (2006) argue that the biorefinery is the most optimal and sustainable option to produce biofuels and
biomaterials using biomass resources. NREL (2009) has proposed two
technological platforms, viz. sugar ‘biochemical’ platform and syngas
‘thermochemical’ platform for the conversion of biomass into
fuels/chemicals/materials. The research and development are still undergoing for the conversion of lignocellulosic biomass into several products in the biorefinery. Cherubini and Ulgiati (2010) have investigated the
biorefinery concept for the production of bioethanol, bioenergy and biochemicals from two types of agricultural residues, i.e. wheat straw and
corn stover, using the life cycle assessment (LCA) approach. The growing demand for energy, fuels and chemicals is a key driver for the increased interest in the development and implementation of biorefineries
(Cherubini, 2010b). Several efforts have been made for converting renewable biomass into a wide range of fuels, materials and chemicals
(Fernando et al., 2006; Patrick et al., 2010, and Taylor, 2008). Patrick et
al. (2010) have presented the recent advances in biorefinery processing,
considering the treatment of lignocellulosic materials for the production
of value-added products. Conversion pathways for biofuels, co-products,
and biochemicals derived from lignocellulosic biomass and conventional
crops are also presented by Black et al. (2011).
Sugarcane biorefinery involves the conversion of sugarcane feedstock
(including co-products and residue) into food (i.e. sugar) and energy
products/carriers (i.e. bioethanol, biogas, heat, and bioelectricity). Grisi
et al. (2011) have considered sugarcane industries as biorefineries and
developed a model for maximizing economic profit whilst producing
several energy products, including sugar. Figure 9 presents the main energy products, including the processes involved in the sugarcane biorefineries, viz. reception and preparation, sugarcane milling, hydrolysis,
sugar extraction, bioethanol conversion, bio-digestion, and cogeneration.
Gheewala et al. (2011) have also examined the environmental and socioeconomic implications of molasses based ethanol production at a biorefinery complex so as to maximise the utilisation of biomass resources.
Ghatak (2011) has critically reviewed the status of biorefineries, considering feedstocks, products, and processes in the context of substituting
fossil-based products. Renouf et al. (2013) have also investigated the environmental impacts of producing bioenergy, biofuels, and biomaterials
from Australian sugarcane in terms of product diversification in an agroindustry.
In the sugarcane milling, the fibrous material (known as bagasse) and
juice are separated from the sugarcane. Bagasse is used as fuel in the
boilers. Sugar is extracted from the cane juice by the processes of clarification, evaporation, repeated crystallisation and centrifuging, followed by
25
Doc t oral Thes is / Dilip Khat iwa da
cooling and drying. At the end of the repeated crystallisation and centrifugation process when no more sugar extraction is possible, sticky black
syrup is obtained, known as molasses. Hydrous bioethanol is obtained
when the sugar juice or sugar-rich molasses is fermented with yeast and
is repeatedly distilled to create a lean aqueous solution in the distillation
unit. The dehydration process generates anhydrous bioethanol. Furthermore, spent wash (waste water or vinasse) obtained during the ethanol
conversion is treated in the anaerobic treatment plant for the reduction
of chemical oxygen demand (COD) to recover biogas. Vinasse also
serves as a fertiliser in agricultural farming. The sugarcane industries are
self-sufficient in their internal energy requirements. With the use of efficient cogeneration systems and full utilisation of sugarcane biomass (i.e.
bagasse and trash/waste), sugarcane mills can generate a significant
amount of surplus bioelectricity to be sold to the local electricity grid.
Figure 9: Sugarcane biorefinery: different stages of
production plant.
Adopted from Grisi et al. (2011) with modifications
Bagasse - a lignocellulosic biomass, having a definite composition of cellulose, lignin and hemicellulose - can also be used to produce second
generation (2G) bioethanol from the route of hydrolysis. The process of
acid or enzymatic hydrolysis is applied to convert cellulose and hemicellulose into sugar, before being converted into 2G ethanol. In the cogeneration systems, sugarcane biomass (bagasse and trash/waste) and the
biogas recovered during the anaerobic digestion are used as fuels (see
Paper VI for the configuration). The efficient cogeneration systems not
only fulfil the internal heat and power demands but also generate plentiful surplus bioelectricity to be fed into the electricity grid. In fact, the
amount of surplus electricity depends on the state-of-art technologies of
26
Sustainability of bioethanol production in different development contexts: A systems approach
conversion technologies. Additionally, the choice of producing different
products (food or energy or biomaterials) depends on their cost of production, demand and prices, etc. For example, if the price of bioelectricity is high the bagasse is solely used to produce bioelectricity rather than
used for producing 2G bioethanol.
In this study, sugarcane and/or its co-products are considered as feedstock for producing modern bioenergy considering the two diverse cases
of a LDC and an emerging country (i.e. Nepal and Brazil) in terms of agricultural and industrial development. The study begins with traditional/conventional conversion technologies and goes on to investigate the
development of efficient cogeneration plant and biorefinery for the production of bioelectricity and/or second generation (2G) bioethanol using
sugarcane biomass.
27
Doc t oral Thes is / Dilip Khat iwa da
28
Sustainability of bioethanol production in different development contexts: A systems approach
3 Sustainability assessment:
Concepts and frameworks
In this chapter, the basic concepts and frameworks used for sustainability assessment are described, with specific focus on bioenergy systems. Biofuel sustainability initiatives are presented, along with the key criteria and indicators identified for the assessment of bioethanol production. Policy and market instruments,
such as biofuel certification and labelling, are also discussed.
3.1 Defining sustainable development and
sustainability
The concept of sustainable development (SD) is derived from the 1987
Brundtland report - Our Common Future - of the World Commission on
Environment and Development, which stated that "development that meets
the needs of the present generation without compromising the ability of future generations to meet their own needs” (WCED, 1987). Our common Future serves as
a vital milestone achievement in the development thinking process. The
earth summit held in Rio de Janeiro (Brazil) in 1992 was the leading international forum for the political endorsement of sustainability and institutionalisation of sustainable development into the global development movement. A new development model was envisaged through the
adoption of Agenda 21 – the global action for sustainable development
and the Rio Declaration. Agenda 21 endeavours to achieve the twin objectives of environmental conservation and sustainable economic development.
The United Nations (UN)’s Millennium Summit in 2000 led directly to
the formulation of the Millennium Development Goals, setting timebound targets to reduce extreme poverty and to meet the basic need of
the poor population. The World Summit on Sustainable Development
(Rio+10) held in Johannesburg in 2002 was a follow-up conference on
the implementation of previous international agreements, i.e. Agenda 21
and the Rio Declaration. The Rio+10 was not successful in setting stringent commitments and in formulating institutional arrangements required for sustainable development (Waas et al., 2011; Quental et al.,
2011).
29
Doc t oral Thes is / Dilip Khat iwa da
The UN organised the Rio+20 Conference on Sustainable development
(UNCSD) in 2012. Green economy in the context of sustainable development and poverty eradication, and the institutional framework for sustainable development were the main themes of the conference. Heads of
state endorsed the outcome document for Rio+20 - The future We Want
(UNCSD, 2012). The document contains agreements, actions, commitments, challenges, initiatives and announcements for addressing a range
of global issues related to clean energy, food security, and water and sustainable transportation. The Rio+20 was the landmark in setting a wide
range of actions, such as the green economy as a tool to achieve sustainable development, institutional framework/corporate sustainability for
sustainable development and a process to establish sustainable development goals; the need to engage civil society and incorporate science into
policy; the importance of voluntary commitments on sustainable development; a framework for tackling sustainable consumption and production (UNCSD, 2012).
Between 1987 and 2012, the concept of sustainable development has
evolved from the ‘triple wins’ three pillars concept of sustainability to
their inter-linkages between institutional aspects and most recently the
green based economy for sustainable development, which has shifted
emphasis towards a balanced use of resources, and having participative,
corporate and collaborative approaches for the benefit of the planet and
its people. In this context, the sustainability assessment of energy systems in general and bioenergy systems in particular is important for navigating sustainable development pathways towards a green economy.
In general, sustainability covers the realms of environment (planet), society (people), and economy (prosperity). By sustainable development,
we actually mean that the environment, comprising the earth and its
ecosystems, biodiversity, scarce resources and cultures, needs to be sustained, while people (survival, life expectancy, education, equity and
equality), economy (wealth distribution, consumption), and society (institutions, social capital, states, regions) need to be developed (Kates et
al., 2005)
The concept of sustainable development and its underlying three pillars
have become important in dealing with the prosperity of nations. In
identifying indicators for sustainable energy systems, the current state,
economic and social systems, driving forces, and the responses of the
institutional set up should be dealt with, and their interconnection considered, in order to determine the current situation regarding the sustainability of the energy system as shown in Figure 10. Economic prosperity, social development and environmental integrity are well connected and involve trade-offs between their varying objectives. Thus it
30
Sustainability of bioethanol production in different development contexts: A systems approach
is very difficult to deal with these factors in isolation. The three pillars
always reinforce each other (Hediger, 2000). For instance, environmental pollution always involves economic costs/activities. Poverty, equality and social justice are also intertwined. Moreover, institutional
strengthening i.e. networking, collaboration and cooperation between
stakeholders, and political stability are also vital in order to enable sustainable development in low-income and developing countries.
Figure 10: The three pillars of sustainability and their interaction in
the sustainable energy system
Adopted from IAEA, Fact Sheets
Sustainable development aims to maintain the balance of the overall
system. Economic sustainability includes investment, benefits and the
availability and mobility of scarce national resources. Environmental
sustainability is the ability of the natural environment (air, water, soil,
biodiversity, landscape and forests/greenery) to sustain human life. Social sustainability covers issues of equity and justice in wealth distribution, for example job creation, and human rights. The social aspects also include democratic participation, social acceptance, working conditions, land use rights, child labour, health and safety. Similarly, sustainable development of the bioenergy (biofuels) system is also very significant in terms of creating economic prosperity, and putting in place social and environmental safeguards. There are several approaches, methodologies, and conceptual frameworks for sustainable development designed for achieving the sustained health benefits and environment protection (Meyar-Naimi and Vaez-Zadeh, 2012; Waheed et al., 2009),
which can also be used for developing comprehensive energy systems.
31
Doc t oral Thes is / Dilip Khat iwa da
The concept of sustainable development and sustainability has evolved
over time, including policy and institutions within the traditional three
pillars (economic, social and environmental) along with finding linkages
and overlaps between them. There have also been attempts to define
the concept and its importance in addressing the sustainability associated with energy production and use (Cramer et al. 2006, Stamford and
Azapagic, 2011). Cramer et al. 2006 have provided a framework for assessing the sustainability criteria. Frameworks and approaches for assessing the sustainability of energy systems vary greatly due to their
scope and methodology (Stamford and Azapagic, 2011). Additionally,
the introduction of sustainability concepts viz. SIA (sustainability impact assessment), SEA (strategic environmental assessment), and RIA
(regulatory impact assessment) have become useful in identifying the
impacts of different plans/programs and policy options that considers
the economic, environment and social dimensions of sustainable development (Gnansounou, 2011).
In the context of analyzing the sustainability of biofuels, several countries have developed their own sustainability principles, criteria and certification schemes (Gnansounou, 2011). Diaz-Chavez (2011) has described
the interconnectivity and linkages between the social, economic, environment, and policy and institutions, depicting an approach for biofuels
sustainability assessment. Socio-economic and environmental indicators
of the bioenergy system should be considered as an integral part of sustainability, which also includes policy and institutions. In order to meet
sustainability objectives, underlying themes should be dealt with in an integrated manner rather than separately. Approaches for biofuel sustainability are divided into two categories. The first approach is focused on
climate change impacts, which is measured by Life Cycle Assessment
(LCA) tools, while the second approach, going beyond the assessment of
carbon, also considers certification schemes and sustainability principles
(Nicollier et al., 2011).
The definition of sustainability assessment is not static and requires an
understanding of the merits of different options and integrated systems
(Dale et al., 2013). It evolves depending on local conditions and the priorities of stakeholders in different institutional contexts, spatial and temporal scales, and socio-economic structures. We need to find synergies
and trade-offs amongst social, economic and environmental gains and
burdens while analysing any production systems. An integrated approach
is required to deal with the environmental, economic and social issues.
The socio-economic benefits of bioenergy systems should be closely
linked with environmental burdens and social challenges such as food
security, and conflict over natural resources e.g. water and land use. The
economic competitiveness of biofuels can be improved when market
32
Sustainability of bioethanol production in different development contexts: A systems approach
mechanism are applied based on environmental externalities/pollution
(Dale et al., 2013). The carbon market and the associated taxation system
could make biofuel production viable. Thus, government policies, market instruments, and incentive could help in analysing inter-linkages between socio-economic and environmental sustainability indicators. In the
following sections, environmental, socio-economic, and cross-cutting
dimensions for assessing the sustainability of bioenergy systems are further described and elaborated on. Considering our limited fossil reserves
on our carbon-constrained planet, the thesis considers the resource utilisation and climate change impacts, i.e. energy and climate gains, of bioenergy systems with a focus on sustainable development.
3.2 Assessing the sustainability of
bioenergy: An integrated systems
approach
Energy security, rural development, and the climate change agenda motivate the production and utilisation of biofuels derived from energy crops
and residual biomass. Sustainability criteria are needed to justify the appropriateness of these energy systems. Interaction between the three pillars of sustainable development is crucial, complex, and multidimensional in the biofuel production chain, which includes the types of feedstock,
land use, conversion technologies, material and energy flows, and pollution.
There is a vast amount of literature on the sustainability assessment of
energy systems in general and the bioenergy system in particular (Afgan
et al., 2000; Cramer et al., 2006; Elghali et al., 2007; Evans et al., 2009;
Buchholz et al., 2009). Four sustainability indicators, viz. resource (e.g.
fossil fuel and energy consumption), environment (e.g. emissions and
pollution), social (e.g. jobs), and economic (e.g. investment, cost) are
used for assessing the sustainability of energy systems (Afgan et al.,
2000). Zhou and Thomson (2009) have found that energy security, economics (trade balance, the price of petroleum, an improved economy),
social dimensions (increased jobs in the agricultural sector, improvement
in farmers’ income), and environmental impacts (climate change and air
quality) are the main driving forces behind the development of biodiesel
and bioethanol in Asia. Cramer et al. (2006) have proposed six criteria on
the theme of sustainability for biomass production, viz. greenhouse gas
emissions, competition with food and the local applications of biomass,
biodiversity, economic prosperity, social well-being, and the environment. Smeets et al. (2006) have assessed the sustainability criteria viz. the
ecological, economic and social impacts of sugarcane-based ethanol production in Brazil, in comparison with Dutch sustainability criteria. GHG
33
Doc t oral Thes is / Dilip Khat iwa da
balances, competition with food & energy supply, biodiversity, wealth,
welfare and the environment were used as determining criteria. These
criteria might also be useful to establish a product certification system
for the international market. Environmental or ecological impacts cover
water use, water pollution, land use, forest protection and biodiversity,
soil erosion, greenhouse gas emissions and energy balance. On the other
hand, socio-economic criteria might include competition with food production, number of jobs, income distribution and land tenure, wages,
worker rights, child labour, social responsibility and benefits (Smeets et
al., 2006). Elghali et al. (2007) has developed a sustainability framework
for the assessment of bioenergy systems in terms of economic viability,
environmental performance, and social acceptability. To ensure the sustainability of bioethanol production chain, Nicollier et al. (2011) have
proposed the following minimal criteria: acceptable working conditions,
consideration of levels of water and atmospheric pollution, and respect
for soil. It is found that environmental performances of biofuel production are highly reliant on system boundaries, the treatment of coproducts and allocation choice, and functional unit, etc. (Gnansounou et
al., 2009).
Goldemberg et al. (2008) have discussed the sustainability of ethanol
production from sugarcane, considering air quality improvement, rural
development, biodiversity, deforestation, soil degradation, water source
contamination, food vs. fuel production, and labour conditions in the
fields. They have also discussed sustainability aspects of ethanol production, namely environmental and social factors, along with the following
sustainability criteria, as suggested by the Cramer commission (Cramer et
al., 2006): (a) energy balance, (b) environmental aspects, such as gaseous
emissions from sugarcane and ethanol production, or due to sugarcane
burning), water (water availability, water pollution - organic pollutants,
inorganic pollutants), land use (the expansion of sugarcane, land competition - ethanol versus food crops), soil, biodiversity; (c) social aspects
and social impacts such as labour conditions, job creation, wages and income distribution, land ownership, working conditions. Zhou et al.
(2007) have selected four sustainability indicators for assessing biofuels economics, environment, energy, and renewability. The energy indicator
represents how much energy is required to produce biofuel and renewability is evaluated using the rate of exploitation of natural resources, such
as fuel-wood. Gnansounou (2011) has presented a logic-based model for
assessing the sustainability of biofuels. Silalertruksa and Gheewala (2009)
have assessed the environmental sustainability of ethanol plants in Thailand, resulting in a significant deviation in the sustainability measurement
among existing plants even if the same feedstock was used. Evans et al.
(2009) have performed the sustainability of renewable electricity generation systems considering the following indicators: the price of generated
34
Sustainability of bioethanol production in different development contexts: A systems approach
electricity, lifecycle GHG emissions, the availability of renewable
sources, energy conversion efficiency, land requirements, water consumption, and social impacts. The cost of electricity, GHG emissions,
and conversion efficiency for energy generation varied significantly depending on the choice of technologies. Goldemberg et al. (2008) also
found that biofuels production and trade could contribute to local development and GHG emissions reduction in a cost effective manner subject to the adequate economic and social safeguards.
Yan and Lin (2009) have mentioned energy security, climate change, rural development and poverty alleviation as the driving forces of sustainable biofuel production. The energy and food security debate is crucial
when discussing the sustainability of bioethanol because agricultural land
is used to produce feedstocks, and these same feedstocks can alternatively be used for food production, such as sugarcane and corn. Biofuel and
food prices have become an important factor in Asia when considering
biofuel production, due to their conflicting nature, in terms of price,
which could subsequently lead to political instability (Zhou and Thomson, 2009). Sheehan (2009) has elaborated that LCA is used for assessing
the sustainability of biofuels, not only when it comes to net energy balance or carbon footprint, but also expanding it to include global land and
water resources, global ecosystems, air quality, public health and social
justice. He has shown that research on the topic 'biofuels and sustainability' and 'ethanol and life cycle' has increased six-fold and three-fold respectively from 2006 to 2008 (Sheehan, 2009). Smeets et al. (2008) have
evaluated the environmental and socio-economic impacts of the production of ethanol from sugarcane in the state of Brazil for the purposes of
product certification. Energy and GHG balances of bioethanol production were investigated by Gnansounou et al. (2009). Phalan (2009) has
given an overview of the social and environmental costs and benefits of
biofuels in Asia, and the major factors identified were land use, feedstocks used, technology issues and scale. According to Schubert and
Blasch (2010), bioenergy can only play an important role in greenhouse
gas (GHG) reduction when it is produced in a sustainable way, thus the
biofuel-pathways with minimum environmental and socio-economic
problems should be promoted. Initial subsidies could also be instrumental in promoting environmentally benign biofuel promotion processes.
Government policies, such as mandatory blending targets, tax exemptions and subsidies are the driving forces for biofuel production in many
countries (Sorda et al., 2010). The development and selection of the sustainability criteria for bioenergy depends on feedstock characteristics and
different production pathways. Buchholz et al. (2009) have also screened
35 sustainability criteria from a survey of experts, which are grouped into
three the pillars of sustainability. Regarding the experts’ views, which
were based on the attributes of relevance, practicality, reliability, and im35
Doc t oral Thes is / Dilip Khat iwa da
portance, only two criteria, namely energy balance and greenhouse gas
balance, were found to be the most critical, and local social parameters
such as compliance with laws, food security, participation, human rights
and social cohesion were ranked lower down. Competition between food
and bioenergy production, and deforestation were two of the sustainability criteria used in the potential assessment of modern bioenergy sources
in one of the low-income or least developed countries (LDCs) in Africa Mozambique (Batidzirai et al., 2006).
Several studies have been performed to assess the sustainability of production systems, national policy, and products at the national and regional level, for example, US food systems (Heller and Keoleian, 2003),
agriculture systems (Hayati et al., 2010), bioenergy systems (Buytaert et
al., 2011; Rösch et al., 2009), nuclear energy (Stamford and Azapagic,
2011), and biofuel policy (Janssen and Rutz, 2011). Janssen and Rutz
(2011) have provided an overview of sustainability of biofuels in Latin
America, considering risks and opportunities for the integrated assessment of the biofuel sector.
Assessing the economic, social and environmental sustainability of biofuel production may not be sufficient at the stage when the emergence of
different methodological issues concerning the accounting of sustainability criteria is involved. Culture and institutional stability appear as additional two pillars of sustainability, but can be merged into the societal
dimensions and considered within a system approach (Parris and Kates,
2003). It should be noted that social and environmental sustainability indicators are closely linked and interconnected (Carrera and Mack, 2010).
For example, food security is strongly related to household income since
a fraction of marginal income will be spent on food (FAO, 2011a). The
UN – Food and Agricultural Organization (FAO) also proposes socioeconomic guidelines for the development of modern bioenergy systems
(FAO, 2011b) in order to minimise the risk of jeopardizing food security.
They have analyzed the social indicators for the assessment of societal
effects of different energy systems covering four main criteria, viz. the
security and reliability of energy provision, political stability and legitimacy, social and individual risks, and quality of life. Policy and legislation
including incentives and policy barriers are considered as the crosscutting dimension of sustainability. Institutional networking within national government, capacity development and well-being, and international consideration/collaboration across the globe would reinforce the
issues related climate change impacts, food and fuel prices, regional energy security and sustainable bioenergy production and trade, etc. Institutional and policy dimensions are apparently linked to socio-economic
sustainability. Cross-cutting policy and institutional sustainability dimension include legislation, incentives, barriers, networking, technological
36
Sustainability of bioethanol production in different development contexts: A systems approach
innovation, public private partnerships (PPPs), organisational development, international collaboration across the globe, lobbying and political
decisions (Diaz-Chavez, 2011). These criteria would reinforce the issues
related to climate change impacts, food and fuel prices, regional energy
security and sustainable bioenergy production and trade. Many institutional and policy (e.g. good governance) aspects are important and relevant for the sustainability of bioenergy production (GBEP, 2011). It
should be noted that social and environmental sustainability indicators
are closely linked to the social impact assessment (SIA) and environment
impact assessment (EIA), (Carrera and Mack, 2010). Stable and transparent governance is essential for providing energy security (Sovacool and
Mukherjee, 2011). Good energy governance is also required to manage
complex 'energy trilema': energy security, climate change mitigation, and
energy poverty (Gunningham, 2013).
Nicollier et al. (2011) have proposed a global framework to determine
the sustainability of bioethanol supply chains, which allows a comprehensive international comparison. The framework based on three criteria
viz. relevance, reliability and adaptability to the local context, has been
applied for a specific case, including the environmental, social and economic issues of locally produced bioethanol in Switzerland compared
with imports from Brazil. Brazilian bioethanol is found to be energy efficient and economically attractive compared to Swiss ethanol. Afionis and
Stringer (2012) have examined the commitment of the EU to the norm
of sustainable development, reflecting its efforts to promote sustainable
biofuel promotion. It is argued that the European Union (EU) has been
making efforts towards integrating environmental aspects into social, political and economic activities. Energy security concerns could also be
addressed through the development of stringent climate policies.
Stamford and Azapagic (2011) have proposed 43 indicators for addressing the techno-economic, environmental and social sustainability issues
related to energy systems. McBride et al. (2011) identified 19 environmental sustainability indicators for bioenergy systems and grouped them
in the six categories, viz. soil quality, water quality and quantity, greenhouse gas flux, biodiversity, air quality, productivity. The 'productivity'
category or net primary productivity (NPP) is a measure of the condition
of the land (e.g. soil fertility, weather conditions, topography) and ecological processes (e.g. photosynthesis and respiration), which would be
useful in determining the sustainable human use of the biosphere. The
indicator, above ground net primary productivity (ANPP), is used to assess the ecosystem productivity of bioenergy-associated land use. Indicators of environmental sustainability are also interconnected with economic and social sustainability as economies and societies rely on the
provision of ecosystem services (McBride et al., 2011). Several national
37
Doc t oral Thes is / Dilip Khat iwa da
and international initiatives such as the Roundtable on Sustainable Biofuels and the Global Bioenergy Partnership are dedicated to develop
comprehensive sets of sustainability indicators for bioenergy systems.
It should be noted that sustainability criteria mainly focus on environmental aspects. The EU sustainability schemes have not sufficiently covered social sustainability requirements therefore it is necessary to incorporate social sustainability concerns in the biofuels sustainability assessment. German and Schoneveld (2012) have presented a comparison of
the recently approved seven voluntary ‘EU sustainability schemes’ based
on the type of biofuel and feedstock. Social sustainability considerations
are primarily analyzed. Labour rights, land and resource rights, food security, livelihood impacts and contributions to rural develop and crosscutting issues are the five key social sustainability parameters included in
the conceptual framework. The social sustainability of bioenergy systems
includes livelihoods, food security, and safety of people. Stakeholders’
engagement and transparency, human rights, and working conditions are
also considered. While the economic aspects of bioenergy sustainability
encompass costs/benefits analysis, techno-economic performance, prices and costs of production processes and products. Afionis and Stringer
(2012) have investigated how the social, environmental, economic and
temporal dimensions of sustainable development are dealt with while
promoting the biofuel strategy in the EU. There is a lack of coherent,
comprehensive and policy-relevant syntheses of the environmental and
socio-economic impacts of biofuels (Gasparatos et al., 2013). Two
frameworks/approaches viz. sustainability science and ecosystem services are used for developing a unified framework for synthesizing biofuel impacts (Gasparatos et al., 2013). However, it is difficult to develop
unified studies when there is high scientific uncertainties and disagreement.
Koponen et al. (2013) have estimated the GHG emissions of various
biofuel chains in Finland as per the EU-RED sustainability criteria,
mainly focusing on uncertainties and the sensitivities of certain parameters. Efforts are being made for reducing the uncertainty of the climate
impacts of biofuel production, also for promoting the harmonised and
accurate sustainability criteria for biofuels. Reduction of GHG emissions
is one of the key goals for bioenergy policies.
The identification of sustainability criteria and indicators help concerned
stakeholders judge the worthiness of bioenergy systems with regards to
the choice of feedstock, management practices, and conversion processes/industrial factory operations. Furthermore, many indicators are used
in certifying sustainable bioenergy systems. Sustainability criteria and indicators would also ease in developing voluntary certification, labelling
38
Sustainability of bioethanol production in different development contexts: A systems approach
and sustainability standards (van Dam et al., 2008). The need to assess
the environmental and socio-economic sustainability of biofuels along
the whole production chain becomes necessary when the market share
and trading of biomass feedstock and biofuels expands. The sustainability aspects include energy and GHG balances, land use change, competition with food security, rural development and employment generation,
etc. Van Dam and Junginger (2011) also mentioned that political barriers,
conflicts of interest, differences in views and norms (ethical standards),
implementation and verification issues are the main obstacles for the
harmonisation of biofuel certification schemes. In order to establish the
harmonisation of the biomass and bioenergy sustainability system, concerted efforts and actions should be introduced with the engagement of
concerned stakeholders. While implementing certification systems in biofuel production, the selection of the Chain of Custody is one of the important aspects, which is used to trace the product along the supply
chain (van Dam and Junginger, 2011).
It is important to scrutinise the production of biomass feedstocks used
for bioenergy and sustainability requirements for agricultural commodities. Dale et al. (2013) have organised 16 socio-economic indicators of
bioenergy systems under six categories: social well-being, energy security,
external trade, profitability, resource conservation, and social acceptability. They identified a set of 10 key indicators such as employment,
household income, fuel price volatility, net present value, public opinion,
which are likely to have major effects on social and economic suitability
of bioenergy systems. Additional indicators such as food security, energy
security premium, effective stakeholder participation would be further
refined for consistently applying the assessment of bioenergy systems.
While return on investment and terms of trade (price of exports/imports) would complement economic perspectives.
Sustainability criteria/indicators are developed for assessing the bioenergy/biofuels production systems. Table 1 presents a set of criteria that are
useful for decision makers/concerned stakeholders who want to analyze
the sustainability of bioenergy systems. Key biofuel sustainability criteria
identified and considered for analysis in this dissertation are selected
based on the current evolving trend for the biofuel production and use at
different stages of technological development and geopolitical conditions. This thesis attempts to identify the most pertinent sustainability
criteria/indicators across the supply chain, including feedstock production and logistics, biofuel processing and logistics, and biofuel end uses.
In this way, there is great concern over the sustainability of biofuel in
both developed and developing countries. For the low-income or LDCs,
whose main primary energy source is traditional biomass, issues of sus39
Doc t oral Thes is / Dilip Khat iwa da
tainability are high on the agenda, since rural populations live in conditions of utter poverty and do not have enough resources for economic
growth. Aiming at reducing GHG emissions and increasing the security
of energy supply in the transport sector, the European Union (EU),
United States (US), and other developed countries have set targets for
biofuel production. This has consequently led to an increased production
and trade of biofuel in developing and developed countries. Thus it is
necessary to scrutinise the sustainability issues and the associated parameters in the biofuel supply chain, production, use and trade at the global
level.
3.3 Biofuel sustainability initiatives:
Certification and standards
In order to guarantee the sustainability of biofuel production, various social, environmental, and economic criteria or indicators are developed.
These indicators should be measured in a transparent way. Certification
systems have been mainly developed in order to verify the stipulated sustainability criteria/indicators or to ensure the compliance with the specific requirements for the standards and quantitatively measure the sustainability. A wide range of initiatives have been undertaken for the development of sustainability standards and biomass certification systems (van
Dam et al., 2008 and 2010; Gnansounou, 2011; Scarlat and Dallemand,
2011). Van Dam et al. (2010) have presented an overview of the various
certification initiatives, which are developed to safeguard the sustainability of bioenergy, especially liquid biofuels, highlighting the differences
and similarities between these initiatives. Sustainability requirements in
the production and use of biomass and bioenergy in various countries
and at regional level are also presented by van Dam et al. (2010).
The IEA bioenergy Task 40 also published an overview of the current
biomass certification schemes (van Dam et al., 2008). The concerns of
biofuel sustainability are also addressed through biofuel certification
schemes (Scarlat and Dallemand, 2011). Various certification schemes
cover a wide range of product systems, including feedstock production,
biomass conversion and end-use of final energy products. Scarlat and
Dallemand (2011) also presented an overview on the latest development
of the main initiatives and approaches for the sustainability certification
for biofuels and/or bioenergy. Various certification schemes for the
production of biofuels from energy crops are analyzed at the global level.
Biofuel certification is the key to address the environmental and social
impacts of bioenergy systems. Harmonisation, integrated sustainability
assessment approach, and monitoring and control are required to ensure
the sustainable production of biofuels when it comes to develop the cer40
Sustainability of bioethanol production in different development contexts: A systems approach
tification schemes including the various environmental, economic and
social aspects, as well as indirect effects (Scarlat and Dallemand, 2011).
The effect of indirect land use change (iLUC) is still uncertain since it is
directly related to sustainable land use planning and spatial analysis, food
security, and expansion of land for biofuel production.
Many countries have developed biofuel sustainability criteria and certification schemes aiming at producing sustainable biofuels. In Europe, biofuels sustainability initiatives have also been carried out at country level,
which consists of sustainability criteria, principles and biomass certification schemes. The UK has implemented the “RTFO (Renewable
Transport Fuels Obligation)” for the carbon and sustainability certification of biofuels, including the methodology for the accounting of GHG
emissions. The RTFO developed sustainability reporting based on environmental and social principles and their related criteria: carbon/biodiversity/soil conservation, sustainable water use, air quality and
workers’ and land rights. Thornley et al. (2009) have presented sustainability constraints on UK bioenergy development. Greenhouse gas savings, land availability, air quality impacts and facility sitting are key sustainability constraints. In the Netherlands, the Cramer Commission for Sustainable Production of Biomass - was formed to develop a certification scheme and sustainability criteria for the production of biomass for
energy (Cramer et al., 2006). In Germany, the International Sustainability
and Carbon Certification (ISCC) project has developed an international
certification system for biomass and bioenergy, which considers feedstock derived from agriculture and forestry. The ISCC standard considers six different principles such as conservation of biodiversity, protection of soil/water/air quality, safe working conditions, human/labour/land rights, compliance with laws and international treaties
and good management practices. In the certification criteria, the sustainability requirements of biofuel/biomass production, requirements related
to the GHG emissions savings/calculation methodology and the traceability and mass balance.
In the European Union (EU), as part of the sustainability scheme and
monitoring/reporting requirements for biofuel, the Renewable Energy
Directive (EU-RED) has postulated a set of sustainability criteria (EC,
2009a) in order to assess their eligibility for a 10% share by 2020. Similarly, the Fuel Quality Directive (EC, 2009b) has also set sustainability
requirements for biofuels. Both the directives have a common approach
on how to reduce GHG emission and conserve biodiversity while producing biofuels. The Member States of the EU are now implementing
the sustainability criteria and the GHG calculation in the national legislation. In the EU, Biofuels should meet a minimum GHG savings of 35%
compared to fossil fuels that would increase to 50% in 2017 and 60% in
41
Doc t oral Thes is / Dilip Khat iwa da
2018 for new biofuel plants/installations (EC, 2009a). The EU-RED has
included a methodology for accounting lifecycle GHG emissions of different biofuels pathways. Feedstock cultivation on the marginalised or
degraded land is promoted providing a bonus of GHG savings. Whilst,
the RED restricts the production biofuel feedstocks on land with a high
biodiversity value, carbon-rich or forested land or wetlands. The European Commission is lately working towards identifying the impact of indirect land use change (iLUC).
Several initiatives have been established for biofuel sustainability certification schemes for crops used as feedstock for biofuels. The Roundtable
on Sustainable Palm Oil (RSPO) was created in 2004 and aims to promote the production and use of sustainable palm oil and developing
global standards for sustainable palm oil. The RSPO certification scheme
has been applied in palm oil producing countries, mainly Indonesia and
Malaysia. The certification criteria include key economic, social and environment aspects such as the conservation of natural resources and biodiversity, economic and financial viability, compliance with laws and regulations, transparency, the consideration of employees and communities.
The RSPO certification scheme also outlines requirements for certification and allows the tracking of certified palm oil. The Roundtable for
Responsible Soy Production (RTRS) developed a sustainability standard
for soy production to reduce social and environmental impacts and improve economic conditions. The RTRS standard includes five principles:
legal compliance and good practices, labour conditions, community relations, environmental responsibility and good agriculture practice. The
Bonsucro - Better Sugarcane Initiative (BSI) has postulated sustainability
criteria and standards for the assessment of sugarcane production, and it
has been recognised as one of the voluntary schemes in the EU. The BSI
also proposed a methodology for the calculation of GHG emission from
sugarcane cultivation, processing to sugar and/or ethanol, including the
emissions associated with direction land change.
Biofuel certification initiatives such as the Roundtable on Sustainable
Biofuels (RSB), US - Renewable Fuel Standard (RFS), the California’s
Low Carbon Fuel Standard (LCFS) are developed at the international
level. The Roundtable on Sustainable Biofuels (RSB) initiative formulated international sustainability standards for biofuels. The RSB standard
defines the criteria for sustainable biofuel production including best
practices in the production, processing and use of biofuels and GHG accounting methodology. In the US, the Council on Sustainable Biomass
Production (CSBP) developed voluntary sustainability standards and a
certification system for sustainable bioenergy production considering
biofuel production from agricultural biomass and non-food sources. The
key sustainability criteria include: climate change, biological diversity, wa42
Sustainability of bioethanol production in different development contexts: A systems approach
ter quality and quantity, soil quality, socio-economic well-being and integrated resource management planning. The Global Bioenergy Partnership (GBEP) also developed sustainability indicators covering (a) environmental (GHG emissions, land and ecosystems, air quality, water
availability, biodiversity, land use change, (b) social (food security, access
to land, water and other resources, rural and social development, access
to energy, labour conditions, human health and safety, and (c) economic
and energy security (economic development, economic viability and
competitiveness, access to technology and energy security) dimensions
(GBEP, 2011).
It was therefore found that several initiatives on biofuel sustainability
and certification schemes have been developed for biofuels feedstock
(BSI, RTRS, and RSPO), biofuels (EU-RED, RSB, ISCC, UK-RTFO,
US-RFS, and US-LCFS), and bioenergy production (GBEP). However, it
should be noted that biofuels certification initiatives are not harmonised
yet. Policy makers, non-governmental organisation (NGO), academic,
and research institutes should be involved in the formulation of biofuel
certification standards. It is necessary to establish common sustainability
assessment frameworks while defining sustainability indicators (e.g. land
use change) and developing approaches/methodologies (e.g. GHG emission calculations), aiming to harmonise the approaches and sustainability
assessment criteria. Unification or harmonisation of biofuel certification
systems can be made through international agreement and ISO standardisation process. Different initiatives on the development of sustainability
criteria and certification schemes should be harmonised for deriving definitions, approaches and methodologies (Scarat and Dallemand, 2011).
To promote sustainability, biofuel certification schemes should include
the entire production steps/processes and multiple end-uses such as fuel,
food, fodder, fibber and bio-materials. While implementing the certification schemes, reliable and transparent verification and enforcement
mechanism is required, including regular monitoring and control systems. It should be noted that biofuel sustainability initiatives are primarily focused on climate change impacts and the metric for assessment is
lifecycle GHG emissions. Hence, certification schemes are also closely
linked to climate change policies. Van Dam et al. (2010) pointed that a
strong international cooperation is needed to harmonise biofuel certification schemes particularly in terms of biodiversity and land use issues.
CEN (European Committee for standardisation) has also formed a
committee for 'Sustainably produced biomass for energy applications'.
The CEN addresses social (employment and welfare, labour conditions,
competition with food, and land use rights), environmental (soil, water
and air quality, land use change, loss of carbon stocks) and economic aspects of sustainability, also including EU-Renewable Energy Directive
43
Doc t oral Thes is / Dilip Khat iwa da
(EU-RED) as a base for the biofuel certification schemes. It should be
noted that the introduction of sustainability criteria in the European
CEN standard would help the use of unified principles and methodologies, also facilitating the compliance with the sustainability regulatory requirements.
As previously mentioned, the reduction of GHG emissions is one of the
key goals and overarching sustainability criteria of the European Commission’s Renewable Energy Directive (EU-RED). The sustainability criteria in the RED include: targeted GHG emissions savings from biofuel
production, restriction of raw material/biomass production from land
with high biodiversity value, high carbon stock and peat-lands. The national mandatory renewable energy targets and GHG emission savings,
and associated government support are accounted only when biofuels
comply with the sustainability criteria. Social and economic sustainability
criteria are not included in the EU-RED.
Additionally, in order to promote the sustainable production of biofuels
and guarantee GHG savings compared to fossil fuels, it is necessary to
monitor/check the sustainability requirements of biofuels through monitoring schemes. The European Commission (EU) has approved various
seven voluntary schemes in order to verify the compliance of sustainable
biofuel production in July 2011 covering different biofuels and geographical locations. The recognised schemes are: ISCC (German's International Sustainability and Carbon Certification, for all types of biofuels),
Bonsucro EU (Roundtable initiative for sugarcane based biofuels, with a
focus on Brazil), Round Table on Responsible Soy EU RED (RTRS,
with a focus on Argentina and Brazil), Roundtable of Sustainable Biofuels (RSB, for all types of biofuels), 2BSvs (French initiative: Biomass
Biofuels Sustainability Voluntary Scheme, for all types of biofuels),
RSBA (industry initiative for Abengoa RED Bioenergy Sustainability Assurance, covering their supply chain), Greenergy (industry initiative
Greenergy Brazilian Bioethanol verification programme). The schemes
adequately cover the sustainability requirements of the EU-RED. After
verifying where and how the biofuels are produced, the scheme can issue
a certificate of biofuel/product. Six additional voluntary schemes such as
Roundtable on Sustainable Palm Oil RED scheme and Ensus voluntary
scheme under RED for Ensus bioethanol production have been recognised after July 2011. Details about the biofuel certification schemes can
be found at EC (2012).
Various initiatives have been developed for the different EU proposed
methodologies for estimating GHG emissions in the biofuel production
chain. Methodological approaches are seemingly distinct, resulting in difficulties to development an internationally harmonised methodology.
44
Sustainability of bioethanol production in different development contexts: A systems approach
However, discussions are ongoing to develop a unified methodology for
accounting GHG emissions. Debates also include land use change (i.e.
type and conversion) and indirect land use change (iLUC) issues. The
United Nations Food and Agriculture Organisation (FAO) also commissioned the biomass and food security (BEFS) project with the objectives
to (a) develop principles, criteria and indicators on sustainable bioenergy
production that safeguards food security (b) disseminate works related to
food security and ongoing bioenergy sustainability initiatives such as
GBEP and RSB, and (c) to seek an international consensus and unification on the sustainability principles, criteria and indicators.
The development of sustainability frameworks for biofuel assessment are
evolving and integrated system approaches are required for establishing
methodological coherences among different biofuel sustainability and
certification schemes. For ensuring compliance with the EU sustainability criteria, a number of initiatives have developed biofuel standards in
order to promote or facilitate biofuel trade to the EU (Scarlat and Dallemand, 2011). Afionis and Stringer (2012) have also related the EC’s
RED directive with social, environmental, economic and time dimensions. There is a need for a certification system for biomass and bioenergy. Van Dam and Junginger (2011) investigated the ongoing development of sustainability criteria for solid and liquid bioenergy in the EU,
including the harmonisation of certification systems. The geographical
diversity, crops and processes for biomass and bioenergy are the main
limitations for the harmonisation of a European biomass certification
system. Certification schemes or product certification systems are developed for many agricultural and forest products, including biofuels/bioenergy derived from energy crops. The certification systems
mainly help to ensure whether the product systems meet the criteria or
standards stipulated in the rules or regulations. Certification systems also
allow the verification of the compliance with the specification. Van Dam
and Junginger (2011) have analysed the environmental and socioeconomic criteria for sustainable biomass and bioenergy certification. As
a result of stakeholder consultation, minimisation of GHG emissions
and optimisation of energy balance are found to be the most relevant
sustainability criteria.
The European Commission (EC) has recently published a proposal to
minimise the climate impact of biofuels by amending the current legislation particularly the RED on biofuels. The proposal includes indirect
land use change (iLUC) factors in reporting GHG emissions savings of
biofuels. In the EU’s 10% target for renewable energy in the transport
sector by 2020, biofuels from food crop-based energy crops is limited to
5%. This would avoid conflicts with food security to some extent and
stimulate the development of second generation biofuels. The proposal
45
Doc t oral Thes is / Dilip Khat iwa da
also hinted at providing market incentives for the 2nd and 3rd generation biofuels obtained from algae, straw, and various types of wastes
feedstock that do not require additional land.
Sustainability standards have been enacted in Europe and the United
States to promote sustainable biofuel production and use, mainly aimed
at reducing lifecycle GHG emissions (carbon intensity), i.e. the Low
Carbon Fuel Standard (LCFS) policy approach. In the US, two lowcarbon fuel standards are in place, viz. the federal Renewable Fuel Standard (RFS) and the California Air Resources Board’s Low Carbon Fuel
Standard (LCFS) (Yeh and Sperling, 2010; Scarlat and Dallemand, 2011).
The RFS introduced the volumetric target of renewable fuel in transport
and the threshold of the lifecycle GHG emissions of different biofuels
while the California’s LCFS has formulated the policy to increase the
share of low carbon fuels by setting a target of 10% reduction in the carbon intensity of transport fuels by 2020. In the EU, the European
Commission (EC)’s Renewable Energy Directive (EU-RED) and the
UK’s Renewable Transport Fuels Obligation (UK-RTFO) have formulated policies or adopted standards for the production and use of sustainable biofuels. The sustainability standards are mainly focused on accounting lifecycle GHG emissions. There are several biofuel certification
schemes which describe the rules and procedures for the certification of
biofuel production, considering all steps involved in the production processes viz. feedstock cultivation, collection and transport, and processing
and production of biofuel. The EC’s recognised voluntary schemes support member countries in achieving the sustainability requirement of biofuels. In addition, labelling systems for sustainable biofuels have also
been developed, which specifies how the minimum socio-economic and
environmental standards/criteria can be met.
This thesis attempts to find the evolution of sustainability aspects at various stages of technological and economic development. The case of the
low-income country of Nepal provides sustainability dimensions in relation with how the low-grade biomass co-product (i.e. Molasses) is converted into the commercial modern bioenergy systems in the form of bioethanol. While the case of Brazil presents how the sustainability and
methodological aspects around the most influencing criteria i.e. climate
change impacts can be related in bioethanol production. Finally, the thesis finds how the sugarcane bioethanol industry can be optimally developed to produce more energy services in terms of providing secure sustainable energy from available biomass.
46
Sustainability of bioethanol production in different development contexts: A systems approach
3.4 Identifying the sustainability criteria
and indicators for bioethanol
production
Following the theoretical framework, initiatives, and certification
schemes discussed above for the assessment of sustainable bioenergy/biofuel production, a set of sustainability criteria and indicators are
identified. Table 1 provides an overview of the sustainability dimensions,
viz. environmental, economic, and social, including cross-cutting policy
and institutional dimension. Identified biofuel sustainability criteria/indicators vary across the globe, depending on different stages of
technological and economic development. Thus there are many different
and important criteria to be considered in this context. In low-income or
LDCs such as Nepal, the scarcity of commercial transport fuels, the flow
of hard currency, with state-subsidies on the imports of petroleum, and
local air pollution in cities are the motivating factors for using a blend of
bioethanol in gasoline. Energy security and the diversification of
transport fuels, along with the issues of food security (i.e. sugar), environmental problems, such as water pollution, and GHG emissions, play
a vital role in the sustainability of bioethanol. Employment generation in
sugarcane cultivation and industrial operations, and the use of domestic
resources for economic growth at a local and regional level are to be assessed when evaluating the sustainability of bioethanol in developing
countries. Energy security and climate change mitigation are the main
goals of the bioenergy production and use in developing and developed
countries (Scarlat and Dallemand, 2011). It should be noted that sustainability criteria for bioenergy systems are interrelated. The technical viability of bioethanol production is also important. Empowering local communities, strengthening institutions among concerned stakeholders and
political stability are all necessary for the sustainable development of bioethanol in low-income countries. Technological innovation, biofuel market formation, and commodity (i.e. biofuel) trade, and government support on the advent of new technological solutions could help to promote
the optimisation of biomass resources for the production of more energy
services.
Firstly, in order to assess the sustainability of bioethanol production in
low-income countries with the case of Nepal, energy analysis, GHG balance and other prospects of sustainable development such as direct economic and environmental benefits are investigated (also see Khatiwada,
2010, and Paper I - III). Two important sustainability indicators: net energy and greenhouse gas (GHG) balances have been analysed in the life
cycle framework. Many of the other criteria have been discussed from a
sustainability point of view, but more as a means of analysing and defining the problem, thus lacking the necessary depth for arriving at major
47
Doc t oral Thes is / Dilip Khat iwa da
conclusions. Secondly, in order to contribute to establishing a unification
in terms of the GHG accounting procedures, methodological aspects on
the estimation of lifecycle GHG emissions are scrutinised, considering
regulatory schemes in the US and EU for the evaluation of the Brazilian
sugarcane ethanol (see Paper IV). This analyses the methodological similarities and divergences for estimating GHG emissions, including agricultural practices, direct and indirect land use change (LUC and iLUC), and
ethanol processing and co-product allocation/credits. Thirdly, the advent
of the sustainability dimensions in relation to resource optimisation for
the development of bioethanol industry for energy security is performed
(see Paper V and VI). The main sustainability indicators include: profitability, product or energy diversification, technological innovation and
choice, security of energy supply, among others. Market, technological
and policy sustainability aspects of producing modern energy services,
i.e. second generation ethanol and/or bioelectricity from residual sugarcane biomass are also performed.
The economic and social factors of biofuel production, which play a key
role in determining the sustainability of bioethanol production, are also
discussed so as to justify the research questions and objectives of the
thesis. However, this study is limited to evaluating the direct economic
and environmental benefits in a systems approach. The optimisation
studies on the use of sugarcane biomass (i.e. bagasse and residues) for
the production of second generation bioethanol and/or bioelectricity on
the systems costs, lifecycle emissions, and international trades are also
performed. Biofuel sustainability issues related to social aspects, social
lifecycle assessment, and indirect land use (iLUC) could possibly be the
scope of future analysis.
48
Sustainability of bioethanol production in different development contexts: A systems approach
Table 1: Sustainability criteria/indicators for evaluating biofuel production and use as a transport fuel
(Summarised from Khatiwada, 2010; Scarlat and Dallemand, 2011; DiazChavez, 2011; McBride et al., 2011; Buytaert et al., 2011)
1. Environmental dimension
•
Local air pollution: (emissions of pollutants: direct and indirect such as CO, SOx,
NOx, tropospheric ozone, and suspended particulate matters (PM10 and PM2.5) from
the combustion in feedstock production, processing as well as in final use/burning
liquid biofuels)
•
Lifecycle GHG emissions (CO2 equivalent: CO2 , CH4, and N2O)
•
Lifecycle energy balances: conversion efficiencies, fossil energy inputs required per
unit useful energy output (MJ)
•
Productivity (above ground and net primary productivity): determines the ecosystem
productivity of bioenergy and sustainable human use of the biosphere
•
Biodiversity and maintenance of ecosystems: monocultures, loss of species, changes
in abundance of species, degradation or loss of natural habitat, safeguarding agro and
forest-ecosystems
•
Soil quality/pollution: total organic carbon, total nitrogen/eutrophication/changes in
nutrient cycling/use of agrochemicals, bulk density (water holding capacity), erosion
•
Water quality/pollution and quantity: wastewater management, surface and groundwater impacts, eutrophication, toxicity, lack of dissolved oxygen, availability of water
for other uses
Change in land use pattern: land cover, biochemical fluxes, hydrological cycles and
ecological balances
•
•
Resource conservation/natural resource efficiency/renewability: depletion of nonrenewable energy resources, efficient utilisation of natural resources
•
Fossil fuel substitution
•
Protecting land and forests: land conservation (including use of degraded land),
avoiding deforestation and desertification
•
Adaptation capacity to environmental and climate change risks
49
Doc t oral Thes is / Dilip Khat iwa da
2. Economic dimension
•
Profitability/microeconomic sustainability: Costs and benefits analysis (cost efficiency), internal rate of return, net present value (NPV)
•
Economic stability: project lifetime, technological innovation and product diversification
Macroeconomic sustainability and improved trade balances, including foreign investments
•
•
Energy security, reliability, and diversification
•
Synergy for industrial and agriculture growth
•
Market formation and economies of scale
•
Local economy and availability of resources (capital)
•
Savings on oil imports
•
Economic instruments: subsidies/tax exemptions
•
Carbon trading (under CDM) and low-carbon/green economy
3. Social dimension
•
•
Social acceptability and transparency: public opinion and effective stakeholder participation
Food security vs. energy security: land available for food production, including food
prices
•
Employment generation, household income, and wages
•
Rural and local development
•
Trade union, workers' facilities & safety (working conditions)
•
Child labour and working hours
•
Poverty reduction
•
Equality, equity and trust, social cohesion, and cultural sovereignty
•
Compliance with laws
•
Human rights/property rights/ land use rights
•
Standard of living
•
Social security (health and education)
4. Cross-cutting policy and institutional dimension
•
Local, national, and regional legislation
•
Political incentives and barriers
•
Institutional strengthening, networking, and capacity development
•
International co-operation and collaboration
•
Technology transfer and knowledge development
•
Public-Private-Partnerships (PPPs)
•
Pressure groups and lobbying
50
Sustainability of bioethanol production in different development contexts: A systems approach
4 Methodological approach
In this chapter, life cycle assessment (LCA) is explained, with specific focus
placed on a case study developed for bioethanol production in Nepal. Critical review of regulatory schemes and complementarity of producing bioelectricity with
hydroelectricity are briefly described. Techno-economic analysis of upgraded biorefineries is presented, along with an overview of the optimisation model used in
this thesis.
4.1 Defining life cycle assessment (LCA)
Life cycle assessment (LCA) is a concept used to evaluate the environmental performance of a product or service during its entire lifespan.
LCA is a holistic systems approach and takes into account the inputs and
outputs of the entire production system, viz. raw materials, energy and
waste, at every stage, from resource extraction (raw materials acquisition)
to the final utilisation and disposal of the product. LCA has become important since it encompasses all the processes and environmental discharges during the production phases of the product, thus avoiding the
shift of environmental problems from one location to another along the
production chain (USEPA, 2006). The results of LCA have increasingly
been used as a decision-making policy tool for the selection of products,
and for environmentally friendly product-certification.
Rebitzer et al. (2004) and Pennington et al. (2004) have elaborated on
LCA application and practices. ISO 14040 - standards/series (ISO,
2006a and 2006b) also define the LCA concept and methodologies. A
LCA study comprises four phases: goal and scope definition, inventory
analysis, impact assessment, and interpretation (see Figure 11). Goal definition and scoping describe the objectives of the analysis, the production processes and system boundaries. The purpose of the study is
measured as a functional unit. The functional unit in LCA is a measure
of quantified performance of products or services, and it enables comparison between the products / services under consideration. In the inventory analysis, the material inputs/outputs are identified and quantified, for example, natural resources (energy, land, water etc.) and environmental releases (e.g. emissions or wastes). Human and ecological effects that occur due to resource usage/consumption or emissions/waste
released into the air, water or soil are taken into account in the impact
assessment. This phase reveals the contribution made by different impact
51
Doc t oral Thes is / Dilip Khat iwa da
categories, for example, resource depletion, climate change, land use,
eco-toxicity, human and ecological health, acidification, and eutrophication. Following the inventory analysis and the impact assessment, the interpretation of the LCA is ultimately carried out to select the product or
service based on the envisaged environmental performance and in order
to comply with the objectives of the study. Thus, LCA provides a comprehensive environmental overview of the product, from cradle to grave.
Figure 11: Life Cycle Assessment (LCA) Framework.
Source: ISO (2006b)
In the LCA of production systems, system boundaries, functional units,
allocation methods, conversion technologies, raw material or feedstock
characteristics, and associated parameters play an important role in the
final evaluation of environmental impact, e.g. GHG emissions of
biofuels/bioenergy production. Cherubini (2010a) has presented the
application of the LCA methodology to bioenergy systems in order to
evaluate GHG balances in comparison with fossil reference systems.
Bird et al. (2011) have also illustrated a LCA approach to estimate the
net GHG emissions of bioenergy. As a result of different approaches,
the results of available studies differ from each other significantly
(Gnansounou et al., 2009 and Cherubini et al., 2009). Allocation methods
are used to divide the resource consumption (e.g. fossil fuel inputs), and
environmental burdens (e.g. GHG emissions) when we get multiple
products or co-products. Allocation is the partitioning of material/energy/emissions flows and related environmental impacts between
52
Sustainability of bioethanol production in different development contexts: A systems approach
co-products. It has a key role in determining the result of the assessments. The International Standards Organisation (ISO) has provided
concepts and methods/guidelines for the allocation procedures in LCA
(see ISO, 2006a and 2006b). There are three types of allocation methods,
viz. economic allocation, mass or energy allocation, and system expansion (or substitution method). Allocation procedures in the biofuel production chain have been discussed by various authors (see Burgess and
Brennan, 2001; Ekvall and Finnveden, 2001; Larson, 2006; Heijungs and
Guinée, 2007; Nguyen and Hermansen, 2012). The choice of allocation
methods significantly affects the results of LCA. In addition, the issues
of co-product allocation are highly debated and controversial in the development of LCA methodology. Therefore, it requires a proper judgment and thorough understanding of the quantitative and qualitative values of co-products such as energy and mass balance, market prices, alternative uses and substituted product while selecting the right allocation
methods.
There are lots of applications of the LCA concept in evaluating renewable and sustainable energy systems. The LCA concept and methodologies have been widely applied in evaluating bioenergy and biorefinery
systems. Liquid biofuels are increasingly seen as potential substitutes for
gasoline and diesel in transportation. It is, therefore, important to assess
the environmental performance of biofuel production and consumption,
and also to compare them with conventional fossil fuels. Several LCA
studies and reviews have been conducted to investigate the impacts of
the lifecycle resource consumption and environmental burden of bioethanol production from different feedstocks, and they are primarily focused on the lifecycle net energy balance and GHG balances (see, for example, Shapouri et al., 2004; Farrell et al., 2006; Macedo et al., 2008; Dai
et al., 2006; Nguyen et al., 2007a/b/c, 2010; von Blottnitz and Curran,
2007; Gnansounou et al., 2009; Cherubini et al., 2009; Hoefnagels et al.,
2010; Xunmin et al., 2009; Börjesson and Tufvesson, 2011; García et al.,
2011; Liu et al., 2013).
In this thesis, life cycle assessment (LCA) methodology is used to investigate the lifecycle energy and greenhouse gas (GHG) balances for molasses-based ethanol (MOE) in Nepal (see Paper I and II). Energy use or
resource utilisation provides a measure of the total amount of primary
energy (non-renewable/fossil fuels and renewable energy resources) extracted from the earth systems, measured in MJ (Guinée, 2002). Whereas, climate change is a measure of GHG emissions (measured in
kg.CO2eq) which enhances greenhouse effect, resulting in the rise of
global average temperature (IPCC, 2006). Molasses is a low-value byproduct resulting from sugar production. Material and energy inputs and
their GHG emissions in sugarcane farming (fertiliser application and irri53
Doc t oral Thes is / Dilip Khat iwa da
gation), transportation, milling, fermentation, distillation and the dehydration processes are considered in the analysis. The system boundary
covers local agricultural practices, the harvesting of sugarcane, cane milling, the ethanol conversion phase (through the fermentation, distillation
and dehydration route), and waste management. The definition of system
boundaries, local sugarcane growing practices, harvesting, factory operations and waste management, and allocation methods in LCA are some
of the key features of the sustainability assessment of bioethanol carried
out in Nepal. In Brazil, where ethanol production is not only fully commercially mature but where it is internationally traded, methodological
investigation on the accounting of GHG emissions is indispensable.
Regulatory schemes in the EU and US have used the lifecycle approach
for evaluating the GHG emissions of Brazilian sugarcane ethanol (Paper
IV). While optimizing sugarcane biorefineries for the production of
more energy services, lifecycle systems costs and GHG emissions in the
entire supply chain of the bioelectricity and biofuel production are also
taken into account (Paper VI).
4.2 LCA as a tool for sustainability
assessment
LCA conventionally covers environmental sustainability, but efforts have
been made to extend the concept to cover the three pillars of sustainability, including economic prosperity and social integrity. The future of
LCA is likely to encompass all aspects of sustainable development, and
the life cycle costing will provide policy decision-makers with information on investment and return, while social aspects might include indicators of millennium development goals (MDGs) in a holistic approach (Hunkeler and Rebitzer, 2005). LCA analyses have been carried
out for the sustainability assessment of various products/services during
the last decade. For example, Heller and Keoleian (2003) have scrutinised the economic, social and environmental dimensions of the US
food system, taking into account the interaction between LCA and sustainability throughout the life cycle. Zhou et al. (2007) have analysed single- and multi-dimension sustainability assessment criteria for the sustainability assessment of fuels in the life cycle framework, including renewability indicators and sustainability indexes. Moreover, Zah et al.
(2009) have outlined an idea for the standardisation and simplification of
life cycle assessment, as a driver for more sustainable biofuels, using a
web-based sustainability check-list for benchmarking sustainability criteria. Von Blottnitz and Curran (2007) have performed life cycle assessment (LCA) of biofuel production considering environmental impacts
categories such acidification, human toxicity, and ecological toxicity.
54
Sustainability of bioethanol production in different development contexts: A systems approach
There are many lifecycle studies of biofuels, which are used to assess fuel
sustainability. Many of them have focused on the evaluation of the GHG
balances (Gnansounou et al., 2009). However, the result of lifecycle
GHG emissions varies significantly, depending on the LCA approach
used, type and characteristics of biomass feedstocks, system boundaries,
functional unit, reference energy systems, conversion technologies,
treatment of co-products, direct/indirect land-use change, among others
(Cherubini et al., 2009; Cherubini and Stromman, 2011, Khatiwada and
Silveira, 2011). Some of the main concerns being addressed at the moment refer to the material and energy flows and direct and indirect impacts of land use change caused by biofuel production.
The conceptual framework and basic guidelines for sustainability assessment includes relevance analysis, impact analysis and assessment optimisation (DETEC, 2004). This can also be applied to bioethanol production. The main aim of the sustainability assessment in this thesis is to
evaluate and optimise bioethanol production and consumption in relation to sustainable development objectives. Sustainability assessment is
also a systematic and comprehensive approach, and the relevance analysis determines the sustainability criteria in detail. Impact analysis evaluates whether sustainable development has been achieved or not. Finally,
the system is optimised for further improvement. These steps are illustrated in Figure 12b. Linkage or integration seems important when the
system can also be optimised with the help of objective functions to secure the best, most environmentally benign options (Azapagic and Clift,
1999). In this way, there is a close link between life cycle assessment and
the sustainability assessment of biofuel production (see Figure 12). Additionally, Curran (2008) has investigated how LCA approach can be used,
and integrated for assessing the sustainability of bio-based products, e.g.
biofuels. It is found that the linkage between LCA studies and the paradigm of sustainability is important for decision-making process. In order
to evaluate the life cycle sustainability assessment (LCSA) of products,
Klöpffer (2008) has proposed a conceptual formula, which includes all
three components of sustainability, viz. environment, economy, and social aspects. For this, the combination of LCA or environmental life cycle assessment, life cycle costing (LCC) assessment, and societal or social
life cycle assessment (SLCA) is required. Similarly, Heijungs et al. (2010)
have also presented a framework for LCSA by revisiting the ISO-LCA
framework, and describing different models. The framework considers
the interaction between environmental and other sustainability dimensions in the lifecycle approach. UNEP (2011b) illustrates how it is possible to combine all three sustainability pillars from the ‘cradle to grave’.
Thus, the LCA approach can be used for an overarching LCSA of products.
55
Doc t oral Thes is / Dilip Khat iwa da
4.2.1
Defining net energy and greenhouse gas
(GHG) balances
Two important sustainability criteria – energy efficiency (net energy balances) and greenhouse gas (GHG) balances have been defined along the
entire product-chain, depending on their corresponding impact categories, viz. resource consumption/depletion (energy use) and climate
change (see Chapter 3). The actual net energy and GHG balances of bioethanol production in Nepal can then be estimated (Paper I and II).
Fig.12(a) Life cycle assessment (LCA)
framework. Adopted from
ISO (2006a)
Fig.12 (b) Sustainability assessment procedure.
Adopted from DETEC (2004)
Figure 12: Integration of LCA and sustainability assessment.
 Net energy balances
Energy balances primarily deal with the lifecycle energy efficiency of bioethanol and the savings in non-renewable fossil fuels compared with bioethanol in the entire product-chain. There are defined terminologies for
dealing with energy balances. The net energy value or balance (NEV or NEB)
of bioethanol (EtOH) is the difference between the energy content of
the bioethanol produced and the total primary energy inputs (fossil plus
renewable) in the entire fuel production cycle.
𝑁𝐸𝑉 = 𝐸𝑓 − 𝐸𝑖
(1)
where, Ef is the energy content (lower heating value) of ethanol, Ei is the
total amount of primary energy inputs
56
Sustainability of bioethanol production in different development contexts: A systems approach
Net renewable energy value/balance (NREV) is calculated as follows:
𝑁𝑅𝐸𝑉 = 𝐸𝑓 − 𝑁𝐸𝑖
(2)
where, NEi is the non-renewable energy or fossil fuel inputs.
The energy yield ratio is defined as the ratio between the energy content of
bioethanol and the total fossil energy required to produce it.
𝑒𝑛𝑒𝑟𝑔𝑦 𝑦𝑖𝑒𝑙𝑑 𝑟𝑎𝑡𝑖𝑜 =
𝑒𝑛𝑒𝑟𝑔𝑦 𝑐𝑜𝑛𝑡𝑒𝑛𝑡 𝑖𝑛 𝑒𝑡ℎ𝑎𝑛𝑜𝑙
𝑓𝑜𝑠𝑠𝑖𝑙 𝑒𝑛𝑒𝑟𝑔𝑦 𝑖𝑛𝑝𝑢𝑡
(3)
NREV and the energy yield ratio provide essential information necessary
to assess the contribution of biofuels to energy security, while NEV
gives the analysis of the total input/out of energy, including renewables.
Note that the threshold limit is NREV > 1. In this study, energy recovered from by-products within the system, i.e. excess bagasse and biogas
are also incorporated into estimates of NEV, NREV, and energy yield ratio.
 Greenhouse gas balances
Total net emissions of greenhouse gases (GHG) are estimated from
greenhouse gas balances, including both release and absorption through
the life cycle. The main GHGs considered in the analysis are: carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). The effect of
these gases is measured using Global Warming Potential (GWP), expressed in CO2 – equivalent (CO2eq.). The net CO2 emissions are considered to be neutral along the product chain of bioenergy systems since solar energy is absorbed by plants/energy crops through the photosynthesis process during their growth, involving carbon fixation from the atmosphere. The estimation of GHG emissions is carried out by taking account of the direct consumption of fossil fuels inputs, the production of
fertilisers/chemicals, activities taking place on agricultural farm land, operations in industrial premises (including emissions during wastewater
treatment), and the final combustion of fuels. The appropriate emission
factors, measured in kgCO2eq per unit material or energy inputs, have
been adopted based on reliable data sources (see Paper II).
GHG emissions in terms of the kgCO2eq m-3 (also, in kgCO2eq MJ-1)
functional unit are evaluated without considering the mechanical efficiency of the end user of bioethanol as the transport fuel. Material and
energy flows in the sugarcane bioenergy systems are normalised to this
functional unit.
57
Doc t oral Thes is / Dilip Khat iwa da
Avoided emissions in the production and combustion/use of bioethanol
(as the gasoline substitute) are estimated using the following equation (4),
considering energy equivalencies of gasoline and bioethanol i.e. 1 GJ of
bioethanol replaces 1 GJ of gasoline.
Avoided life cycle GHG emissions (%)
=
GHG emissions in gasoline − GHG emissions in bioethanol
x 100
GHG emissions in gasoline
(4)
4.3 Realisation of a case study in Nepal:
Sensitivity analysis and development
of scenarios
Sugarcane is one of Nepal’s cash crops, and 2.6 million tonnes of sugarcane was produced from 64 thousand hectares of land, giving an average
yield of 40.6 tonnes per hectare in 2006/07. The trend has been towards
an increase in production, cultivation area, and productivity since
1999/00. Nine sugar mills are operational with a total installed capacity
of 17,050 cane-tonnes per day, and are located in different districts of
the fertile plain land of the South. The sugar industry produces low-value
molasses (4 - 5% of the cane-stalk, w/w) as a by-product, which can be
used for bioethanol production. In order to evaluate the sustainability
aspects of bioethanol production in Nepal, a field case study was carried
out at one of the established sugar industries in Nepal, i.e. Sri Ram Sugar
Mills Pvt. Ltd. (SRSM). SRSM is the only plant that has an installed molasses based ethanol conversion unit. The unit has a production capacity
30 m3 per day and associated ancillaries such as wastewater treatment
with biogas recovery (see Paper I – III). Therefore, factory operations
for molasses-based ethanol conversion in SRSM are considered to be the
best for an ethanol plant in Nepal.
The scope of this case study is limited to a life cycle assessment of resource utilisation (non-renewable or fossil fuel and renewable inputs) and
global warming impacts. The system boundary covers sugarcane farming/harvesting, transportation, cane milling, ethanol conversion phase
through fermentation, distillation and dehydration route, and waste management. Data sources on material, energy, and waste flows (inputs and
outputs) in both agricultural practices and industrial operations were obtained from the field study performed by the thesis author. Figure 13
presents the details of energy and material flows, including emissions and
waste at each stage along the ethanol production chain in the sugar industry in Nepal. While estimating the net energy and GHG balances, en58
Sustainability of bioethanol production in different development contexts: A systems approach
ergy values and GHG emissions associated with machineries/equipment,
industrial installations, and oil/lubricants/chemicals (for factory operations) are neglected in the study. However, energy input and GHG emissions from human labour activities are taken into account, considering
the primary energy requirement based on the 'Life-Style Support Energy'
as mentioned in Paper I. Since open burning before harvesting is a
common practice, the energy content of sugarcane trash/waste is not
considered in the analysis. It should also be noted that the evaluation of
GHG emissions from direct and indirect land use change (LUC and
iLUC) is not in the scope of the analysis.
Land preparation, planting, fertilisers/chemicals application, irrigation,
and harvesting are the major farming activities in the sugarcane field.
Application of fertilisers/chemicals, and use of diesel to run diesel water
pumps required for irrigation correspond to material and energy inputs
in agriculture (see Paper I and II for details). For the purpose of estimating GHG emissions, sugarcane residue (i.e. cane-trash) is also considered.
There are actually two main by-products in the sugar milling process:
molasses and bagasse. Bagasse, a fibrous residual biomass left after the
extraction of cane juice, is used as the fuel input (a source of renewable
energy input into the system) to the boilers. The steam from bagassefired boilers is used in power turbines to generate electricity, and the exhaust steam is utilised as the heat required for the process of sugarcane
milling, distillation and dehydration. Heat and power required in the factory operations are obtained from a bagasse fired cogeneration plant.
Sugar mills are not only self-sufficient in their energy requirements but
they also produce surplus bagasse. However, the excess bagasse is simply
wasted by combusting it in the boilers as there is no provision for selling
surplus electricity to the national grid. Molasses, the sticky black syrup
obtained at the end of the repeated crystallisation and centrifugation
process when no more sugar extraction is possible, are converted into
anhydrous ethanol fuel (EtOH) via the route of hydrous ethanol (95%
(v/v) ethanol, called rectified spirit). The fermentation of molasses and
the subsequent process of repeated distillation generate rectified spirit.
To produce anhydrous ethanol (99.5% v/v), rectified spirit (95% v/v) is
passed through a typical molecular sieve dehydration column/plant before the anhydrous vapour of EtOH is condensed and cooled down to
produce the final bioethanol. It should be noted that bioethanol can currently be only produced from low-value molasses in Nepal. Sugar juice is
primarily used in the production of sugar. Distillery waste water effluent
(spent wash) is treated prior to the disposal because treatment is essential
from an environmental point of view. An anaerobic effluent treatment
plant generates biogas, which is later used to fuel the boilers.
59
Doc t oral Thes is / Dilip Khat iwa da
In the LCA of bioethanol production in Nepal, economic allocation is
used to divide the resource consumption (primary energy), and environmental burden (GHG emissions) in upstream operations when we get
co-products (sugar and molasses). Guinée et al. (2004) describe the economic allocation in the LCA methodology. It is difficult to expand the
system for molasses to substitute a similar functional product since we
cannot be sure which product is being replaced by the use of molasses.
Moreover, sugar and molasses do not offer equal physical relationships
in terms of energy or mass content as it appears unlikely that they serve
the same purpose i.e. food or energy. Economic allocation is preferred in
order to find the most economically favourable outcome in terms coproducts and to inform policy makers about the economic implications
of formulated policy, and at what point the product would no longer be
considered low-value or a waste product (Nguyen and Gheewala, 2008b;
Gopal and Kammen, 2009). Various studies have explored allocation
methods for conducting the life cycle assessment of energy and environmental performance of biofuels, particularly the allocation by market
value method in bioethanol (Nguyen et al., 2007b; Nguyen and Gheewala., 2008a; Nguyen and Gheewala, 2008b; Gopal and Kammen, 2009).
Research by Nguyen and Gheewala (2008b) adopts the economic method to find the environmental and cost performance of cane molasses in
Thailand. In this thesis, the market prices of sugar and molasses are used
to determine the partition of energy consumption, and greenhouse gas
(GHG) emissions between these two products. The average allocation
ratio was found to be 22.2:1, considering the yield of co-products and
market prices (see Paper I and II).
Figure 14 (a-j) shows actual field conditions in agricultural practices, the
transportation of feedstock, and factory operations, including the generation of co-products. Further details about agricultural practices, transportation, cane processing, and effluent treatment can be found in Paper I
and II. The case study primarily covers farming practices on sugarcane
farmland as presently adopted by cane farmers in Nepal, as well as prevailing industrial operations in the sugar industry. In order to accommodate the effect of variations in input parameters, such as fertilisers, diesel
consumption for irrigation, allocation ratio (i.e. the prices of coproducts), and agricultural yields, sensitivity analyses have been performed to estimate both net energy and GHG balances (see Paper I and
II). Scenarios have also been developed at the plant level to evaluate the
consequences of adopting different wastewater treatment processes, with
or without biogas recovery, and the selling of surplus bagasse electricity
to the grid (see Paper II).
60
Sustainability of bioethanol production in different development contexts: A systems approach
Figure 13: System boundary and material flows (per
hectare) for sugarcane-based systems in
Nepal.
61
Doc t oral Thes is / Dilip Khat iwa da
a. Sugarcane plantation, growth, and harvesting
are done by human labour; main material inputs are fertilisers, pesticides, insecticides,
and diesel (to operate water pumps for irrigation). The total duration required for sugarcane growth is 11-12 months, and harvesting time lasts up to five months. The average
productivity is 40.61 tonnes per hectare.
b. Transportation: Different modes of transport for carrying sugarcane feedstock
to the factory gate; they include animal-powered cart (50%), tractor (30%), and
truck (20%).
c. Feeding of feedstock into d. Open burning of sugarcane wastes (tops and
the milling process
leaves)
e.
f.
62
Industrial complex – Sri Ram Sugar Mills. Pvt.
Ltd. (SRSM) runs for about 5 months during
the harvesting season of sugarcane. Industrial
operations include sugarcane milling, which
produces sugar as the main product, and molasses and bagasse as co-products. Bagasse is separated during the crushing of sugarcane while
molasses is obtained at the crystallisation/centrifugal process.
Cogeneration plant: Bagasse-fired industrial boilers (left), and steam turbines
(right) to generate heat and electricity required for the plant
Sustainability of bioethanol production in different development contexts: A systems approach
g. Generation of sugar: The yield is
7 – 9 % of the sugarcane mass
crushed.
h. Generation of bagasse: a co-product
of the milling process and the yield is
35 – 37% of the sugarcane mass
crushed.
i. Distillation plant (left) – molasses-based bioethanol (95% v/v ethanol), and Dehydration plant (right) – molasses-based bioethanol (99.5% v/v ethanol). Approx. 120 tonnes of molasses (42% w/w - fermentable sugar) is required to
generate 30 m3 of ethanol in the distillation plant.
j. Effluent (wastewater or spent-wash) treatment plant where reduction in environmental load occurs along with the generation of
biogas, which is later used as fuel input for
the boilers. 0.53 Nm3 of biogas (68% methane) is produced per kg of COD reduction. In the present state-of-the-art case in
SRSM, 100% biogas is recovered from the
Anaerobic Digestion Process (ADP) and directly fed into boilers.
F i g u r e 1 4 : ( a -j ) R e a l i s a t i o n o f t h e c a s e s t u d y i n N e p a l : S u g a r c a n e f a r m ing and factory operations.
Photographs: Author’s field visit at Sri Ram Sugar Mills Pvt. Ltd. (SRSM),
Nepal
63
Doc t oral Thes is / Dilip Khat iwa da
4.4 A review of regulatory schemes on
accounting lifecycle GHG emissions
Many governments have set biofuel targets in terms of volumetric mandates and/or greenhouse gas (GHG) emission intensity as part of their
energy and climate policies (Timilsina and Shrestha, 2011; Scarlat and
Dallemand, 2011). Climate change impact (i.e. GHG emissions) is one of
the major sustainability criteria for biofuel assessments (see Chapter 3).
Paper IV of this thesis scrutinises the European and American regulatory
schemes for accounting the lifecycle GHG emissions of a biofuel pathway: Brazilian sugarcane ethanol. In the EU, two regulations, viz. the
European Commission's Renewable Energy Directive (EU-RED) and
the UK's Renewable Transport Fuels Obligation (UK-RTFO) are examined whilst other two major low-carbon fuel policies in the US, namely,
the federal Renewable Fuel Standard (RFS) and the California Air Resources Board's Low Carbon Fuel Standard (LCFS) are analysed. A
comparative study is carried out in order to find the methodological
convergences and divergences for estimating the lifecycle GHG emissions. The study also scrutinises major issues and concerns related to agricultural practices, factory operations, and direct and indirect land use
change (LUC and iLUC) so as to harmonise or unify the accounting procedures/methods across the globe.
4.5 Optimizing the ethanol industry: A
systems approach
Efficient utilisation of local biomass resources not only reduces the fossil
fuel consumption but also promote energy security, rural development in
synergy with industrial and agricultural development, thereby reducing
climate change impacts (GHG emissions). There are abundant quantities
of surplus residual sugarcane biomass (bagasse and trash/waste) in sugarcane mills or biorefineries. A large amount of bioelectricity can be produced by using sugarcane biomass after meeting the energy requirements
of sugarcane mills. The thesis conducts how sugarcane biomass can be
efficiently utilised for the production of energy services: bioelectricity
and/or second generation bioethanol. Paper V analyses the potential for
bioelectricity production in Nepal and Brazil using efficient cogeneration
systems, and its complementarity with hydropower. Whereas, Paper VI
uses a techno-economic optimisation study for upgrading sugarcane biorefineries for the production of more energy services in the form of bioelectricity and second generation (2G) ethanol in the state of Sao Paulo
(SP) in Brazil.
64
Sustainability of bioethanol production in different development contexts: A systems approach
4.5.1
Complementarity of bioelectricity with
hydroelectricity
Brazil and Nepal have the highest per capita hydro resource potential for
electricity generation in the World. However, the supply of hydroelectricity is not sufficient to meet the domestic demand in both countries due
to several reasons (see Paper V). One of the common reasons is the seasonal variation of water flows in rivers. Interestingly, sugarcane harvesting and milling operations occur in the dry season when rivers have a
lower flow of water for hydropower. Surplus bioelectricity obtained from
the efficient cogeneration system in sugarcane mills or biorefineries can
provide significant amounts of renewable electricity.
Paper V of the thesis introduces the diverse energy systems of the two
countries, including available energy resources and consumption trends.
Sugarcane bioenergy systems, cogeneration technologies and different
configuration for producing bioelectricity are described. The bioelectricity potential is assessed based on sugarcane biomass resources. The complementarity of bioelectricity with hydroelectricity is examined, before
providing opportunities and barriers (esp. policy and institutions) for the
generation of bioelectricity from sugarcane biomass (Paper V).
4.5.2
Techno-economic optimisation of sugarcane
biorefineries
In Paper VI, a techno-economic optimisation study is conducted using
three technological options: one present technology and two upgraded
technologies, viz. efficient cogeneration systems for electricity generation
(electricity option) and the production of second generation ethanol
through the biochemical conversion of sugarcane biomass (2G ethanol
option). A Mixed Integer Linear Program (MILP) is used to optimise
the selection of technology for producing energy products and services
in sugarcane biorefineries (McCarl et al., 2011). A detailed description
of the model can be found in the previous literature (Leduc, 2009; Wetterlund, 2010). The model has been used in several optimisation studies
for the production of bioenergy, particularly from forest and wood residues in the EU (Schmidt et al., 2011; Natarajan et al., 2012; Leduc et
al., 2012). Figure 15 provides a schematic sketch of the model as applied in this study on energy production from agricultural feedstock in
Brazil. The model is spatially explicit and minimises the costs of the entire biofuel supply chain of sugarcane bioenergy systems, including
sugarcane production (agricultural practices), feedstock transportation,
biomass processing, and biofuel transportation. The costs for emitting
GHG emissions, i.e. carbon tax, are also considered.
65
Doc t oral Thes is / Dilip Khat iwa da
F i g u r e 1 5 : A schematic diagram of the BeWhere model for sugarcane biorefinery in Brazil.
Biomass and energy flows are shown by arrow symbols. Red arrow
shows the additional fossil fuel needed to meet the demand.
The model considers the processing of sugarcane and waste/residues
for energy services in the state of Sao Paulo (SP). The study region is
divided into grid cells with a 0.1 degree spatial resolution (approx. 10
x 10 km). All sugarcane mills that are situated in a single grid cell are
considered as single entity, resulting in a total of 158 sugarcane biorefineries in the entire state. The model does not consider the dynamics
of the sugarcane expansion and new sugarcane biorefineries, but incorporates existing sugarcane mills that would be upgraded for the
increased production of energy services, utilising excess bagasse and
waste/residue. The size and location of the existing sugarcane mills
were obtained from two different sources, UNICA (UNICA, 2012)
and Sugarcane Technology Center (CTC, 2012), respectively. Figure
16 shows the size and location of the sugarcane mills. Distances between the grid points of the existing sugarcane mills were computed
using GIS (Geographical Information) software. The distance is used
for estimating costs and emissions associated with the transportation
of sugarcane feedstock between sugarcane fields and plants.
The objective function is to minimise the total cost (Ctotal) in the supply
chain, which is expressed as:
𝐶𝑡𝑜𝑡𝑎𝑙 = 𝐶𝑠𝑢𝑝𝑝𝑙𝑦.𝑐ℎ𝑎𝑖𝑛 + 𝐸𝑠𝑢𝑝𝑝𝑙𝑦.𝑐ℎ𝑎𝑖𝑛 . 𝐶𝐶𝑂2𝑒𝑞
(5)
Where Csupply.chain is the supply chain cost, Esupply.chain is the supply chain
emissions, and CCO2eq is the cost for emitting GHG emissions.
66
Sustainability of bioethanol production in different development contexts: A systems approach
F i g u r e 1 6 : Size and location of existing sugarcane mills in
the state of Sao Paulo (SP).
Data source: UNICA (2012) and CTC (2012)
The supply chain cost (Csupplychain) consists of: feedstock (sugarcane and
waste/trash) costs and transportation costs (to the production plant), investment and production costs, biofuel transport costs to the specified
supply points, fossil fuel (i.e. gasoline) costs for transport, and income
from the sale of bioelectricity. Note that biofuel is transported to gas stations within the state of Sao Paulo (SP) and/or to a port (Rotterdam/
the Netherlands) in the EU via the port (i.e. Santos) located in the state
of SP. The cost of gasoline in Brazil and in the EU is different.
The supply chain emissions (Esupply.chain) include: Emissions from sugarcane production/agriculture practices, emissions from sugarcane/trash
transport, emissions from plant operations, emissions from biofuel
transport, and avoided emissions from substituted fossil based transport
fuel (in Brazil and the EU) and fossil based electricity.
The total cost is minimised subject to a number of constraints related to
feedstock supply, operation balance in production plants, biofuel trade,
and energy demand. See Leduc, 2009 and Wetterlund, 2010 for the
mathematical expression on how to formulate the objective function and
constraints. The model inputs are: feedstock availability, size and location of the existing plants, transportation distance, annualised costs,
emission factors, carbon tax, plant efficiencies, and the market prices of
fuel and power. The model solves the problem by selecting the least
costly technological option, considering the whole supply chain cost,
emissions, and prices. Thus it does not optimise the profit of a single biorefinery, but rather considers the entire system for the welfare of the
67
Doc t oral Thes is / Dilip Khat iwa da
region. The resulting model output includes: the choice of technological
option, supply chain costs and emissions, the share of 2G ethanol and
bioelectricity, and quantities of biofuel export. It should be noted that
the study ignores the export of ethanol outside the EU and the production of sugarcane bioenergy outside the Sao Paulo region in Brazil.
The supply chain costs for producing energy products in the sugarcane
biorefinery are divided into two categories: (a) mass or volume based
fixed costs (i.e. feedstock cost, investment and operation costs), which
depend upon the amount of feedstock processed and the type of conversion technologies, and (b) distance-dependent feedstock and biofuel
transport costs which are determined by the mode of transport and distance travelled.
The capacity of each base plant is 2 million tonnes (Mt) of sugarcane processed per year. The size of existing sugarcane mills in the state of Sao
Paulo varies between 0.1 and 8 Mt cane per year (UNICA, 2012). The
costs of biomass conversion technologies have scaling effects (Dornburg
and Faaij, 2001). Thus, in order to incorporate or adjust the investment
costs of equipment depending upon the size of sugarcane biorefinery, a
scaling factor (R) is used, which is expressed as:
𝐶𝑜𝑠𝑡𝑎
𝑆𝑖𝑧𝑒𝑎 𝑅
=�
�
𝐶𝑜𝑠𝑡𝑏𝑎𝑠𝑒
𝑆𝑖𝑧𝑒𝑏𝑎𝑠𝑒
(6)
Where Costa and Sizea represent the costs and capacity (Mt cane/year) of
the new plant respectively while Costbase is the known investment costs
for a plant capacity of Sizebase. Considering the value of R as 0.7, the investment costs for different biorefinery sizes can be determined (Remer
and Chai, 1990; van den Wall Bake et al., 2009).
Furthermore, investment costs of plants are annualised considering a 25
year economic lifetime for the plant and an interest rate of 10% using
equation (7).
𝐴𝐶 =
𝐼𝑅
. 𝑇𝐼𝐶
1 − 1/(1 + 𝐼𝑅)𝑡
(7)
Where AC is the annualised cost, IR is the interest rate, TIC is the total
investment costs, and t is the economic lifetime.
In order to investigate the most influencing model parameters, different
scenarios for the upgraded technological options are developed. It
should be noted that the reference scenario represents the existing market and technological conditions. Sensitivity analyses are also performed,
taking a range of input parameters into account.
68
Sustainability of bioethanol production in different development contexts: A systems approach
5 Assessing the
sustainability of
bioethanol production in
Nepal
This chapter presents the sustainability evaluation of bioethanol production in
Nepal. The results of lifecycle energy and GHG balances, and sensitivity/scenario analyses are presented, and compared with other biofuel sustainability studies conducted globally. The need of unified methodologies for the GHG
accounting is identified. Direct economic and environmental benefits and crosscutting issues such as food security, policy and institutions are also discussed.
5.1 Lifecycle energy and GHG balances
The lifecycle energy and GHG balances are used to measure bioethanol
energy efficiency and climate change impacts. While evaluating the energy flows and GHG emissions from the production of molasses based
anhydrous ethanol, the entire product chain has been analysed from the
sugarcane farming, cane milling and molasses to ethanol conversion
phases until the treatment of distillery spent wash. Partitions of the resource consumption (i.e. energy inputs) and climate change impacts (i.e.
emissions) have been done as per the principle of market value/economic allocation in LCA (also, see Chapter 4).
In Nepal, the primary energy consumption and GHG emissions (per
hectare) during the sugarcane farming is 45,372 MJ ha-1 (fossil fuel:
67.5% and renewable energy: 32.5%) and 3,625.3 kgCO2eq ha-1, respectively. Of the fossil fuel inputs, diesel used for irrigation contributes
43.2% and fertilisers/chemicals account for 45.7%. Since transportation
is mainly carried out using animal-driven carts, it has only a relatively
small share - 5.9% of total fossil fuel inputs. Bagasse and biogas supply
energy for the plant’s processes. In terms of GHG emissions, the share
of production and the total application of fertilisers/chemicals is 55%,
while diesel used to power diesel water pumps and trucks/tractors accounts for 29.9%. Human labour, cane trash burning, and returned residues have small shares of the total emissions, with figures of 3.9%, 6.3%
and 4.9% respectively.
69
Doc t oral Thes is / Dilip Khat iwa da
Table 2 shows the primary energy balance in all the processes. The sugar
milling process consumes a large amount of primary energy (73%). It
should be noted that surplus bagasse amounts for 17%, and is also taken
into account in the calculation. To produce one litre of anhydrous bioethanol (99.5% EtOH or MOE), the lifecycle energy input analysis
shows that the renewable energy contribution amounts to 91.7% (31.42
MJ/L) since most of the operations are run using bagasse, biogas and
non-motorised transportation. The only exceptions are the application of
fertilisers/chemicals and irrigation. Fermentation/distillation consumes
12.63 MJ/L, which is the most energy intensive part of the process, followed by sugar milling which consumes 10.46 MJ/L (see Figure 17).
Taking the energy content of anhydrous bioethanol (EtOH) to be
21.2 MJ/L, the net renewable energy value (NREV) is positive
(18.36 MJ/L) but the net energy value (NEV) is negative (−13.05 MJ/L).
The higher positive value of NREV shows that the amount of fossils fuels
used in the production cycle of bioethanol is relatively low. In fact, the ratio between the energy content of bioethanol fuel to fossil fuel inputs (energy yield
ratio) is 7.47. However, the negative value of NEV shows that more energy is required to make EtOH than there is in its final energy content.
In any case, low quality biomass feedstock, i.e. molasses (in terms of
market and energy values), is converted into a high quality commercial
energy carrier - bioethanol.
Figure 17: The contribution of fossil and renewable
energy required to produce 1 litre of
EtOH (MOE) in Nepal, at each stage of
the ethanol production chain.
70
Sustainability of bioethanol production in different development contexts: A systems approach
Table 2: Primary energy balance of sugar milling in Nepal (including
distillation, dehydration and ETP)
Processes
Primary energy required
Sugarcane milling
Fermentation/Distillation
Dehydration
Effluent treatment plant (ETP)
Lighting in the distillation, dehydration, ETP plus electricity in their facilities
Total primary energy required
Primary energy supply
Bagasse primary energy input
ETP biogas input
Total primary energy input
Excess bagasse
% excess bagasse
Sectors
Power (including electricity to facilities)
Heat
Power
Heat
Power
Heat
Power
Power
GJ/day
990.3
4,600.0
73.8
240.2
78.1
54
32.8
54.5
6,123.7
7,036.5
319.3
7,355.8
1,232.1
16.75 %
The lifecycle greenhouse gas (GHG) emissions from the production of 1
m3 of molasses-based anhydrous bioethanol (EtOH) are 432.5 kgCO2eq.
Table 3 depicts the results of the estimation of GHG balances. The net
avoided emissions equate to 1,418.4 kgCO2eq m-3 ethanol, compared with
conventional gasoline (of an equivalent energy amount) which is a 76.6%
reduction in the lifecycle GHG emissions. Moreover, the lifecycle emissions of EtOH measured as a functional unit, per MJ, is 20.42 gCO2eq
MJ-1. Fossil fuels used in the production of fertilisers/chemicals, diesel
combustion (in water pumps and trucks/tractors), and human labour
contributes 51.9% (224.4 kgCO2eq) of the total emissions. Soil emissions
from fertiliser-application and returned residues is the second largest
source with a share of 26.8% (116.1 kgCO2eq). Emissions from boilers as
a result of bagasse/biogas combustion, trash burning, and the combustion of ethanol in vehicles all correspond to small shares (see Paper II for
details).
71
Doc t oral Thes is / Dilip Khat iwa da
Table 3: Lifecycle GHG (CO2eq) balance of molasses-based
ethanol (MOE, EtOH) fuel in Nepal
Activities and constituents
Fertiliser production
Phosphorous (P2O5)
Potash (K2O)
Nitrogen (N)
Chemical production
Insecticides/pesticides
Herbicides
Diesel (irrigation): production & combustion
Diesel (transport): production & combustion
Fertiliser application
N2O from fertiliser N-application
CO2 from fertiliser N-application
Human labour (fossil fuel inputs)
Cane trash burning
N2O (spent wash/stillage)
Returned
N2O (filter cake/mud)
residues
N2O (unburned trash)
Bagasse combustion in boilers (for heat & power)
Biogas combustion in boilers
Sub-total (emissions along the ethanol production
chain)
Emissions from combustion of 1 m3 ethanol (EtOH)
in vehicles
Total lifecycle emissions (production & combustion of
EtOH)
Emissions
(kgCO2eq m-3)
5.95
3.89
48.92
38.66
4.16
95.57
12.96
76.11
22.37
14.25
22.90
1.06
9.13
7.48
35.57
8.56
407.53
25.00
432.53
5.2 Sensitivity analysis and scenario
development
The effect of various technological/market factors and practices such as
the improvement of milling operations, the choice of effluent treatment
plants, the sale of surplus electricity, the economic allocation ratio, and
the agricultural practices (material inputs)/sugarcane yield are investigated in order to find the lifecycle energy and GHG balances. Sensitivity
analyses are performed, which calculate the impact of the most influencing factors on the net energy values and energy yield ratio, while scenarios are developed at the plant level for analysing the GHG balances in
different conditions (see Paper I and II). Results of the energy analysis
and GHG emissions are briefly discussed in the following sub-headings.
72
Sustainability of bioethanol production in different development contexts: A systems approach
5.2.1

Performance at the plant level
Energy efficiency improvements
In the factory operations, there is significant potential to improve the energy balance of the production of bioethanol in Nepal. One important
way to achieve this is to save energy (power and heat). Figure 18 shows
the variation in NEV resulting from a reduction in the plant’s energy
consumption. It has been found that a 10% reduction in energy consumption in the plant helps to increase NEV by 33.5%. The breakeven
point, when NEV reaches zero, occurs at a 30% reduction in energy
consumption. Although this is possible from a technological point of
view, it is difficult to achieve given the current technological configuration of the plant.
Figure 18: Effect of different levels of energy
consumption at the ethanol plant on
NEV values.

Wastewater treatment types and their performances
GHG emissions from wastewater (effluent or spent wash) treatment
plants at the factories/distillery plants are relatively significant, and are
related to the types of treatment process used. The Anaerobic Digestion
Process (ADP, a biological digester) and Pond Stabilisation (PS, also
called the lagoon system) are two common treatment practices for the
treatment of wastewater from sugar and distillery industries. The present
scenario (at the plant level) in SRSM comprises the best available case in
Nepal with wastewater treatment facilities treating 100% of the
wastewater, using ADP to recover biogas, whereby no leakage of biogas
73
Doc t oral Thes is / Dilip Khat iwa da
is allowed into the atmosphere. Recovered biogas is fed directly into
boilers as fuel. Given a scenario of 100% biogas leakage into the open
atmosphere from ADP, the total amount of emissions would be 2,602.1
kgCO2eq (per hectare). The PS process releases 1,551.4 kgCO2eq ha-1 into
the atmosphere. A close examination of the GHG emissions associated
with each of these waste treatment options shows that the ADP treatment process, without any biogas leakage, is preferred.
The results of emissions from ADP and PS treatment plants have been
scrutinised. When 100% of the spent wash is sent through the pond stabilisation process, the lifecycle emissions may increase to 118% with a
value of 4,032 kgCO2eq m-3 ethanol. When 50% of the spent wash is
treated using PS and the remaining 50% fed into the ADP (with biogas
recovery), there is a 21% increase in emissions, compared with emissions
from gasoline. However, if 25% of the spent wash is treated using PS
and the remaining 75% with the ADP, the emissions are reduced by 28%
to a level of 1,332 kgCO2eq m-3 ethanol, as shown in Figure 19 (left).
Thus, the installation and operation of the ADP in sugar and distillery
factories not only recovers energy but also reduces the lifecycle GHG
emissions.
Figure 19: Lifecycle GHG emissions: the case of
treatment type (left) and biogas leakage
(right).
When considering the leakage of biogas from a bio-digester (i.e. from
ADP), 10% leakage would avoid 44% of the lifecycle emissions compared with gasoline. In this case, the value of lifecycle GHG emissions
becomes 1,038 kgCO2eq m-3 ethanol. Figure 19 (right) also shows the total emissions, taking into account biogas leakages in the range of 5 –
25%. If the total leakage of biogas exceeds 23.4% then the lifecycle
GHG emissions of bioethanol will surpass the emission level of its coun74
Sustainability of bioethanol production in different development contexts: A systems approach
terpart, conventional gasoline. Therefore, it is essential to avoid gas leakage if full advantage of the emission reduction is to be achieved from bioethanol production and fuel substitution.

Technological improvements: Grid connection for electricity from
excess bagasse
As found in the estimation of the net energy balances, there is 17% excess bagasse arising from the sugar production chain at SRSM. Sugar
mills/factories in Nepal are located near to industrial corridors where
many industrial complexes operate. The industries suffer from power
shortages, especially in the dry season (December-May), which is the period when hydroelectricity generation is limited and the harvesting of
sugarcane occurs. Industries, therefore, run stand-by diesel power plants
when no electricity is available from the grid. Excess bagasse can be used
to generate and supply electricity to the grid along these industrial corridors. Part of the electricity produced by the diesel power plants can be
replaced by this form of renewable bioelectricity, with a consequent reduction in GHG emissions. It should be noted that boilers and turbines
with their current installed capacities could operate in such a way as to
generate excess electricity though improved efficiency, which would add
both economic and environmental value.
GHG emissions are avoided when surplus electricity produced in the
sugar mill is fed into the national electricity grid to substitute diesel-based
electricity (see Paper II). The total avoided emissions of 646 kgCO2eq resulting from the production of one m3 ethanol are allocated at the ratio
of 618 kgCO2eq for sugar (95.6%) and 28 kgCO2eq (4.3%) for molasses. It
is estimated that the lifecycle emissions of ethanol could be 405 kgCO2eq
m-3 ethanol. Emissions from different activities along the entire sugarcane/ethanol production chain are shown in Figure 20. The total percentage reduction of GHG emissions is 78% based on the production of
1 m3 of molasses-based ethanol (EtOH) in comparison with gasoline.
Technological improvements in the bagasse-fuelled combined heat and
power plant (CHP), such as a high pressure and temperature turbine, can
generate 1 kWh electricity from 1.6 kg of bagasse (Purohit and Michaelowa, 2007) which is more than five times more resource efficient than
the turbines used in Nepal. On a global level, even more efficient turbines can be found. Thus, there is a huge potential to trade-off the entire
GHG balances in the sugarcane systems of Nepal by generating and selling bagasse-fuelled bioelectricity to replace diesel power plants. The utilisation of cane trash/waste for electricity generation, and the improvement and optimisation in industrial processes could further reduce GHG
emissions (also, see Paper V and VI).
75
Doc t oral Thes is / Dilip Khat iwa da
Figure 20: GHG emissions shares from different stages of the
ethanol production chain in Nepal (in the case of
using surplus electricity to substitute diesel).
5.2.2
Market impact on LCA allocation ratio for
determining net energy and GHG balance
Prices of sugar and molasses play a key role in determining the energy
and GHG balances using the market price allocation method (see Paper
I and II). In Nepal, the price of molasses was quite low in comparison
with the international price. As the demand for molasses-based ethanol
increases, it can be expected that the price of molasses will rise. The
price of molasses has been increased by 50%, 100%, 150% and 200% to
see the effect on the energy values and energy yield ratio, whilst the price
of sugar is assumed to be constant. It has been found that the net energy
value (NEV), net renewable energy value (NREV), and energy yield ratio
also decrease with an increase in the price of molasses (see Figure 21).
For example, a 100% increase in the price of molasses leads to a reduction of 14.7% in the NREV with a corresponding energy value of 15.66
MJ/L. The energy yield ratio is also reduced to 3.88 (a 48.8% reduction).
A higher value for the energy yield ratio equates to a higher merit for the
fuel.
Figure 22 shows how the result of the lifecycle GHG emissions increases
when the market prices change towards higher prices, covering the
whole range of sensitivity from the allocation ratio of 24 to 4. When the
market price of molasses increases two-fold, the new allocation ratio i.e.
10.88 (keeping the market price of sugar and yields of the co-products
constant per tonne-cane) would give 844.7 kgCO2.eq m-3 ethanol which is
a 54.4% reduction in the lifecycle GHG emissions compared with gaso76
Sustainability of bioethanol production in different development contexts: A systems approach
line. The full trade-off situation, i.e. when the lifecycle emissions of ethanol are the same as those of conventional gasoline, occurs at an allocation ratio of 4.43 (break-even point). Below this point, it is not worth
producing molasses-based ethanol in Nepal. This sensitivity analysis is
relevant for long-term decision making among investors and government
policy makers as it helps to identify the most cost-effective options for
the low-value product. Furthermore, it shows at what point molasses
should no longer be considered a waste product in the assessment of the
lifecycle GHG emissions.
F i g u r e 2 1 : E ffe c t of c ha n ge s i n t he p r ic e o f
mo la s se s on N R E V a nd th e e ne r gy y ie ld r a ti o .
5.2.3 Agricultural practices and yield improvements
GHG emissions in response to individual variations in the three most
important input parameters, viz. consumption of pesticides, nitrogenfertiliser, and diesel (for irrigation), have been analysed. The parameters
have been varied from a 75% reduction to a 75% increase from the present case. Figure 23 shows the results of the analysis. It can be observed
that the production and application of nitrogen-fertiliser has a greater
impact on GHG emissions than the use of diesel and pesticides. For example, a 50% increase in the use of nitrogen-fertiliser will lead to an increase in GHG emissions to a level of 506 kgCO2eq m-3 ethanol, while
diesel consumption and the application of pesticides would only increase
the emissions to 480 and 452 kgCO2eq m-3 ethanol respectively. An indepth analysis of the full implications of changes in agricultural inputs is
beyond the scope of this thesis. However, this sensitivity analysis gives
an idea about the importance of potential improvements on the agricultural side.
77
Doc t oral Thes is / Dilip Khat iwa da
Figure 22: Sensitivity analysis for lifecycle GHG emissions and avoided emissions (%) as
a function of different allocation ratios for sugar and molasses.
Note: Dots on the primary and secondary y-axis represent the total
emissions and % avoided emissions respectively at the base case allocation ratio, i.e. 22.2:1 (molasses: sugar)
On the other hand, when sugarcane yields are improved, there is a significant reduction in the lifecycle GHG emissions (also, see Figure 23). A
75% increase in the cane yield (i.e. 71 tonnes per hectare) from the present value of 40.61 tonnes/ha could reduce GHG emissions to 306
kgCO2eq m-3 ethanol (14.4 gCO2eq MJ-1) and the avoided emissions would
be 83.5% compared to gasoline. Cane yields are currently relatively low
in Nepal. Therefore, there is plenty of scope for immediate improvements.
5.3 International references on energy
and GHG balances of bioethanol
production
Several studies have estimated the lifecycle energy and GHG balances of
bioethanol derived from various feedstocks, such as sugarcane, cassava,
corn and cane-molasses. Macedo et al. (2008) found that the energy yield
ratio in the production phase of sugarcane was 9.3 in Brazil during
2005/06, taking into account the direct consumption of external fuels
and electricity, the energy required for the production of chemicals and
materials, and the additional energy necessary for the manufacture, construction and maintenance of equipment and buildings. The total GHG
78
Sustainability of bioethanol production in different development contexts: A systems approach
emissions for anhydrous ethanol production were 436 kg CO2eq m-3 ethanol in the same period and could decrease to 345 kgCO2eq m-3 for a
conservative scenario in 2020 (Macedo et al., 2008). Cane productivity
and ethanol yield were the most important parameters affecting the estimation of GHG balances. However, the study has not dealt with the
wastewater treatment of spent wash. Their calculation of total emissions
did not consider the credits from co-products and surplus electricity either which might have had a significant impact on the net GHG balances. Considering molasses as a feedstock for ethanol production in the
average Brazilian mill, Gopal and Kammen (2009) found that the ratio of
sugar and molasses price play a key role in determining the emissions and
the lifecycle GHG emissions were calculated to be 15.1 gCO2eq MJ-1. In
comparison, emissions of 20.4 gCO2eq MJ-1 of GHGs were found in the
case of Nepal, for sugarcane-molasses-based ethanol.
Figure 23: Sensitivity analysis for variations
in material/energy inputs and
sugarcane yield in Nepal.
Nguyen et al. (2007a) have calculated the NEV and NREV for cassavabased bioethanol in Thailand with respective positive values of 8.8 MJ/L
and 9.15 MJ/L. Shapouri et al. (2004) reported that the net energy balance (energy yield ratio) for producing corn ethanol in the USA was 1.67.
The results of NEV and NREV for cassava fuel ethanol, as reported by
Dai et al. (2006), were 7.47 MJ/L and 7.88 MJ/L respectively, in the case
of China. Nguyen et al. (2008)’s lifecycle analysis of sugarcane-molassesbased ethanol calculated the values of NEV (-5.67 MJ/L), NREV (5.95
MJ/L), and energy yield ratio (6.12 per MJ petroleum inputs) in Thailand. The study was quite similar to that of molasses bioethanol in Nepal. However, the results contrast with the values of NEV (-13.05 MJ/L)
79
Doc t oral Thes is / Dilip Khat iwa da
and NREV (18.36 MJ/L) found in the Nepalese case. In the Thai case,
the plant’s energy requirements are not met by bagasse alone; rice husks
and wood wastes are also used as supplementary fuels in the sugar milling process. Coal is a major fuel in the ethanol conversion process, and
biogas is not utilised for process energy. At the same time, excess electricity is sold to the grid as an energy output. In the case of Nepal, the
difference in NEV is due to higher total energy inputs (fossil fuel plus
renewable) while favourable conditions for NREV occur, since energy
requirements are mostly met by renewable sources.
Nguyen et al. (2007b) have analysed the lifecycle GHG emissions for
molasses-based ethanol in Thailand, demonstrating that there is a 31.3%
increase in GHG emissions with an allocation ratio (between sugar and
molasses) of 8.6:1. Emissions from anaerobic PS contributed the largest
share, of 54.1%. However, the study also showed that biogas recovery
from 100% spent wash could reduce GHG emissions by 60.6% compared to conventional gasoline, and further improvements are possible,
up to an 88.8% reduction. In comparison, a 76.6% reduction in total
emissions per litre of ethanol is observed in the Nepalese case, assuming
the best case currently available in one of the established sugar factories.
Greenhouse gas savings (tonnes of CO2eq per hectare) in sugarcane bioenergy systems have also been identified by Nguyen et al. (2010) in the
sugar industry in Thailand. Electricity generation from cane
trash/residues and excess bagasse, and energy extraction from stillage
(wastewater) would reduce GHG emissions. The lifecycle emissions in
the production and use of 1 m3 of cassava-based ethanol were 964
kgCO2eq, which corresponds to 62.9% of the total emission reduction
compared to gasoline (Nguyen et al., 2007c).
Moreover, von Blottnitz and Curran (2007) conducted a review of
assessments of bioethanol as a transportation fuel from the net energy,
greenhouse gas and environmental lifecycle perspective, comparing
energy yield ratios and GHG balances, though with differing
assumptions and system boundaries. The values of GHG emissions and
energy yield ratios differ significantly depending on the feedstock used
and the production practices applied. These studies are important
references but deep comparisons of lifecycle GHG balances is difficult
given the lack of unified methodological procedures in bioethanol
production. Recent studies point out that it is essential to define precise
system boundaries, reference bioenergy systems, geographical location
and the characteristics of feedstock, allocation methods, functional unit,
and energy conversion technologies for a thorough comparison of biofuel chains, among other things, when contrasting LCA and sustainability
issues for different biofuels (Cherubini et al., 2009; Gnansounou et al.,
2009; Cherubini, 2010a; Hoefnagels et al., 2010). Studies need to be
80
Sustainability of bioethanol production in different development contexts: A systems approach
transparent in their methodological choices in order to fully highlight the
environmental effects along the ethanol production chain. Thus, unified
methodological procedures in the production of bioethanol are required
globally for a thorough comparative analysis (also, see Paper IV).
Although it is difficult to compare studies on energy and GHG balances
made in different countries due to different system boundaries and varying methodologies, the case of Nepal is fairly representative for LDCs.
The low fossil fuel input throughout the production chain is mainly a result of traditional practices in agriculture and significant manual labour
inputs. While the modernisation of production has traditionally led to the
increased use of fossil fuels around the world, the analysis in Nepal
shows that significant improvements can be achieved in the total energy
balance of bioethanol production if modern technology processes are
properly applied. This does not necessarily need to lead to higher fossil
fuel consumption along the production chain if both technical and socioeconomic issues are carefully considered. Certainly, an important aspect
in the context of developing countries is the possibility to capitalise on
technologies that are readily available to save on investment costs and
reduce risks. In this context, the bioethanol potential offers a concrete
opportunity for many low-income countries/LDCs.
5.4 Immediate economic and
environmental benefits, and other
sustainability aspects
Nepal has great potential to produce molasses-based ethanol and for it to
be used as part of a blend in gasoline-run vehicles. The increased use of
biofuels not only reduces dependency on fossil fuels but also reduces the
greenhouse gas (GHG) emissions and local air pollution caused by vehicular emissions. In addition, the production of biofuel can serve as a
driver for improvements in agriculture. The direct and immediate benefits of producing ethanol are discussed in detail in Paper III. This section
highlights the key issues related to the potential for ethanol to contribute
towards sustainable development in Nepal.
Nepal could today produce enough bioethanol to introduce an E20
blend for gasoline replacement in the Kathmandu Valley where 70% of
the national gasoline imports is consumed. If motorists were to opt for
an E20 blend, gasoline imports could reduce by 14% or 10,078 m3,
which corresponds to an ethanol requirement of 15,315 m3 per year.
This annual requirement is still lower than the total potential capacity of
the sugar mills, given the availability of molasses for ethanol production.
In the context of the Nepal Oil Corporation (a state owned enterprise,
NOC)’s accumulated huge annual losses due to subsidies on oil/gasoline
81
Doc t oral Thes is / Dilip Khat iwa da
imports, direct annual import savings of US$10.1 million (with E20)
could be achieved through the introduction of an E20 blend. Additionally, the introduction of E20 could avoid 23,397 tonnes of CO2 emissions,
which is 14% of the total gasoline emitted in a year in 2006/07 (Paper
III). In Nepal, vehicles running on ethanol blends also release less air
pollutants compared to pure gasoline.
First generation bioethanol, derived from food crops such as corn/maize
and sugarcane is often debated when it comes to food security and land
use. Nepal can produce 18 million litres of bioethanol annually without
compromising sugar and other indigenous sugar-based food products
(such as Chaku and Shakhar), converting the low-value by-product of the
sugar milling process: molasses. Therefore, there is no trade-off between
food and fuel in terms of bioethanol production in Nepal at its present
scale. The study also finds that there is still significant potential to increase cane yields, which would guarantee a significant increase in ethanol production without the need to bring more land into cultivation.
Given the present conditions, sugar industries are self-sufficient in their
energy requirements. Bagasse generates the heat and electricity required
to run the whole plant. Excess bagasse could be used to provide surplus
electricity to replace diesel-powered electricity in the industrial corridor.
Bioethanol derived from molasses could replace gasoline in the transport
sector. Having made more efficient utilisation of bagasse and canetrash/waste, surplus bioelectricity could be generated to provide power
for nearby industries or to provide lighting for the rural poor, with the
help of rural electrification in the countryside, where 44% of the population still lack electricity. Therefore, the development of sugarcane bioenergy systems would enhance energy security (also, see Paper V).
It is observed that the area occupied by sugarcane is significantly smaller
than the area dedicated to other cash or food crops. At present, sugarcane yields amount to an average of 40.6 tonnes/ha, and could be improved with the help of regional experience and practice in sugarcane
cultivation. Mechanisation of agricultural practices should also be considered in the medium-term. This would enhance food production as
well as that of energy products without the need for more cultivated
land.
Considerable bioethanol potential exists in many LDCs in Africa just as
in the case of Nepal. Mozambique could extract 68 million litres of bioethanol from sugarcane by 2010 (Batidzirai et al., 2006). Current ethanol
production in Malawi is 30 million litres ethanol derived from sugar molasses, which is used to complement the imported fuel (Amigun et al.,
2011). Zimbabwe produced 22.7 million litres ethanol back in 2004.
82
Sustainability of bioethanol production in different development contexts: A systems approach
Amigun et al. (2011) have reviewed biofuels and sustainability in African
countries, showing that many LDCs can produce ethanol from sugarcane
molasses. The development of this potential in African countries can
similarly help to retain foreign currency, reduce pollutants and address
health problems.
The institutional collaboration between concerned private and public
stakeholders, including donor agencies/development partners, plays an
important role in the sustainability of any development project. Both the
political and institutional concerns have become the most urgent issues
to address at this stage when mature conversion technologies are already
available and accessible. Favourable governmental policies such as mandatory bioethanol blends and incentives/subsidies for sugarcane farmers
and private investors can play an important role in the realisation of the
bioethanol potential in Nepal and other LDCs. The institutional set-up
and public-private-partnerships seem weak in the case of Nepal. For example, the introduction of the E10 blend was enacted in 2004 but has
not yet been implemented due to institutional bottle-necks. A comprehensive renewable energy policy is required to boost the production and
use of bioethanol, providing on the one hand incentives for sugarcane
farmers and industries who want to make the investment in bioethanol
production and, on the other hand, the proper institutional conditions to
promote the switch to a new fuel.
Additionally, one of the MDGs (Millennium Development Goals) is to
develop a global partnership for development to address the pressing
needs of LDCs. The role of donors is key in the context of LDCs. Nepal
and other LDCs are largely dependent on development aid so there is
great need to inform donors about the real potential that these countries
have. By improving sugarcane yields and the total energy and GHG balances of ethanol production in Nepal, and by using ethanol blended gasoline in the transport sector, Nepal could earn certified emission reductions (CERs). This could also improve the economic performance of bioethanol plants and help to promote more efficient technologies
(Gnansounou et al., 2005). The CDM scheme could then serve to attract
part of the investments necessary to expand ethanol production capacity
in the country and implement the fuel substitution policies. This would
provide an important contribution to the development of bioenergy in
Nepal and improved access to modern sustainable energy services using
indigenous energy sources.
83
Doc t oral Thes is / Dilip Khat iwa da
84
Sustainability of bioethanol production in different development contexts: A systems approach
6 Accounting GHG
emissions in bioethanol
production
In this chapter, four regulatory schemes used in the EU and US for accounting
the lifecycle GHG emissions of bioethanol production are scrutinised, along with
underlying perspectives towards methodological unification. Major issues and
concerns in the GHG accounting procedures are also presented.
6.1 Estimates of lifecycle GHG emissions
in regulatory schemes
The lifecycle GHG emissions identified as per the four regulations are
discussed. At present, the lifecycle GHG accounting methodologies and
the corresponding results of the two European regulations, viz. EU’s
Renewable Energy Directive (EU-RED) and UK’s Renewable Transport
Fuels Obligation (UK-RTFO) are similar because of the EU biofuels
mandates/targets across Europe. Whereas the rules and results of the
American regulations, viz. the federal Renewable Fuel Standard (USEPA) and the Low Carbon Fuel Standard of the California Air Resources Board (CA-CARB) vary significantly among themselves and in
relation to the European regulatory schemes. While analysing the results
on the main methodologies, systems boundaries, allocation/co-products,
and land-use change (LUC & iLUC) are considered in their lifecycle
analyses. Additionally, results of individual research studies are also presented so as to give a broader scope for comparison of methodological
divergences.
In the EU and UK, the total default emissions values for the Brazilian
sugarcane bioethanol is set at 24 gCO2eq/MJ, giving a 71% GHG emission savings compared to gasoline. Emissions in the production of the
sugarcane bioethanol in the EU-RED and UK-RTFO have been identified in five steps: crop production/cultivation, feedstock transport, conversion to ethanol, transport to ethanol and the filling station. The contribution from crop production/cultivation was about 60%, followed by
the transport of bioethanol (32%). Methodologies for the entire lifecycle
of biofuel from cultivation, processing, transport, to the impact of land
85
Doc t oral Thes is / Dilip Khat iwa da
use-change (LUC) and final use are defined. The production of excess
bagasse bioelectricity i.e. co-product allocation is not considered the regulations. The UK-RTFO has been aligned with the EU-RED rules in
many aspects. In order to harmonise the estimation of biofuel GHG
emissions across the EU, the BioGrace project has also been commissioned in the EU, which has become instrumental in helping unify the
GHG accounting methodologies (see Paper IV).
In the CARB, the production of sugarcane ethanol is dealt with in three
pathways: one baseline average production process and two scenarios involving mechanised harvesting and electricity co-product. Figure 24 depicts the disaggregated values of direct GHG emissions in the entire
production chain, including savings from surplus electricity (i.e. 7
gCO2eq/MJ) and mechanised harvesting (i.e. 8.2 gCO2eq/MJ). The direct
lifecycle emissions are 27.4 gCO2eq/MJ in the average production processes without excess electricity and mechanised harvesting. While, the
emissions from land use change (LUC and iLUC) are estimated by using
the GTAP model and its contribution is found to be 46 gCO2eq/MJ, incorporating the elasticity of crop yields, trade elasticity, and production
volume, etc.
Figure 24: Well-to-wheel GHG emissions for sugarcane
ethanol, including credits from surplus electricity and mechanised harvesting.
Source: CARB (2009)
In the US-EPA regulation, the Brazilian sugarcane bioethanol is treated
as advanced biofuel because of its GHG emissions performance. The
FAPRI-CARD model is used to analyse the international impact of in86
Sustainability of bioethanol production in different development contexts: A systems approach
creased production of imported Brazilian sugarcane ethanol. Alternative
scenarios and biofuel pathways, for example, direct production of anhydrous ethanol in Brazil versus the production of anhydrous ethanol in
the Caribbean, collection of trash for electricity generation versus no
trash collection, are scrutinised while estimating the total GHG emissions. Figure 25 shows the lifecycle emissions in the different scenarios.
The international agricultural emission has the highest share in the total
lifecycle GHG emissions of the Brazilian sugarcane ethanol. If we consider the scenario that excludes credit from fuel production phase, with
no trash collection and no Caribbean pathway, emissions from the international agriculture-sector are calculated to be 36 gCO2eq/MJ (mainly
from farm inputs and fertiliser in Brazil), which is 77% of the total
lifecycle emissions. The scenario with trash collection provides a greater
GHG reduction due to excess electricity production from the combustion of collected sugarcane biomass. Furthermore, N2O emissions (from
crop residues and mineral fertiliser) for Brazilian sugarcane ethanol are
estimated to be 27.8 gCO2eq/MJ. The US-EPA has used proxy N2O
emissions for Brazilian sugarcane ethanol, taking perennial grass as a surrogate. The quantity of emissions from the average land-use change is 5
gCO2eq/MJ (i.e. 11% of the total), out of which domestic land use share
(in the US) is 20% while that of international is 80% (in Brazil). It should
be noted that the GHG emissions savings vary from 59% to 91% compared to the 2005 baseline gasoline.
6.2 Comparisons of the lifecycle
emissions
A comparison of GHG emissions results for Brazilian sugarcane ethanol
in the four regulatory schemes is shown in Figure 26. The result of the
CA-CARB, with average production process and bagasse bioelectricity
credit, has the highest GHG impact (66.4 gCO2eq/MJ). In contrast, the
US-EPA, with the direct Brazilian pathway (No CBI, i.e., ethanol pathway from the Caribbean Basin Initiative) and no trash collection for energy production results in 36.1 gCO2eq/MJ. It should be noted that scenarios for both cases in the US are considered to be similar, i.e. surplus
bioelectricity and direct or no CBI pathway. The GHG estimates for the
regulations in the EU, i.e., the EU-RED and UK-RFTO, which emit an
almost equal amount of the total GHG emissions in each stage of the
biofuel production chain, have the least GHG emissions. However,
emissions from land use change (LUC and iLUC) and tailpipe have not
been considered in the European regulations so far. Surplus bioelectricity credit is also not accounted for.
87
Doc t oral Thes is / Dilip Khat iwa da
Figure 25: Lifecycle GHG emissions in different scenarios of the US-EPA methodology (with and
without residue collection and CBI)
Source: EPA (2010b)
The largest differences between the US-EPA and CA-CARB estimates
are related to emissions from land use change (LUC and iLUC) and agriculture. The emissions from the LUC and iLUC in the CA-CARB carry a
huge contribution of 46 gCO2eq/MJ (about nine-fold compared to 5
gCO2eq/MJ in the US-EPA), but in the US-EPA agricultural emissions is
responsible for the largest share (i.e. 36 gCO2eq/MJ) in its fuel chain (see
Figure 26). The divergences of GHG results, particularly in LUC/iLUC
and agricultural emissions, are mainly due to the elasticity of input parameters (i.e. land conversion), scenarios/volume of the increased production of bioethanol, modelling approaches and system boundaries
(Paper IV). Agriculture emissions in the US-EPA’s results are based on
the FAPRI-CARD model, which is highly sensitive to crop yield elasticity, elasticity of land transformation across cropland, pasture and forest
land, and elasticity of crop yields with respect to area of expansion.
While land use change emissions in CA-CARB results are derived from
GTAP model, which is static and it is difficult to compare the result of
emissions from the land use change due to the different scenarios for
production volume of bioethanol (EPA, 2010a). The uncertainty factor
in the GTAP sensitivity analysis on the conversion of land-use is also
very high. The percentage change in yield with relation to the increase in
land area (area expansion elasticity) is lower in the case of the FAPRI
model.
88
Sustainability of bioethanol production in different development contexts: A systems approach
It is important to note that the amount of GHG emissions from crop
residues is very high (i.e. 26 gCO2eq/MJ) in the US-EPA. However, emissions from crop residues are not taken into account in the CARB. Emissions from agricultural inputs or nitrogen fertiliser (8.7 gCO2eq/MJ), sugarcane farming (1.7 gCO2eq/MJ), and straw burning (8.2 gCO2eq/MJ) are
the only emissions considered. While looking at the emissions from fuel
and feedstock transport, the European regulations, EU-RED and UKRTFO, have a higher amount of emissions compared to the CA-CARB
and US-EPA, mainly due to energy intensity (MJ/t-km) and different
modes of transport. Consideration of round-trip travel distance in the
CA-CARB shows a slightly higher value of GHG emissions than the USEPA, i.e., 6.1 gCO2eq/MJ versus 4.4 gCO2eq/MJ. Refer to Paper IV for
details about the regulations and corresponding emissions in their lifecycle, including data-sources, model descriptions, and comparison of GHG
results with other Brazilian studies. Several studies show that it is difficult to directly compare the results of GHG emissions, mainly due to diverse data-sources, agricultural practices and land use change (LUC and
iLUC).
Figure 26: Comparison of GHG emissions for
s u g a r c a n e e t h a n o l ac c o r d i n g t o f o u r
different regulations.
89
Doc t oral Thes is / Dilip Khat iwa da
6.3 Major issues and concerns about GHG
accounting methodologies
Biogenic GHG emissions from plant soil systems largely rely on agricultural practices such as tillage operations, harvesting techniques, residues
management, and farm inputs/fertiliser application. Tillage operation/field reformation may release a large amount of soil carbon. Emissions from soils and farm inputs (i.e. emission factors) are also sitespecific. Green harvesting system reduces emissions, but residue/trash
left in the field to maintain soil quality might lead to an increased demand for organic inputs, resulting in increased N2O emissions. There is a
huge discrepancy in accounting N2O emissions, especially considering
the climatic condition of soil (i.e. moisture and temperature) and measurement techniques. Spent wash or vinasse could also stimulate N2O
emissions. Soil emissions should be addressed in a more quantitative
way, also incorporating the actual agricultural practices. Adoption of
proxies for the estimation of GHG emissions in agricultural systems is
common. But, the result varies significantly when the IPCC tier 1 approach and the assumption based on perennial grasses as a surrogate of
sugarcane are used. When sugarcane parameters are considered, the final
results on the GHG emissions reduction vary significantly. For example,
the analysis shows that sugarcane ethanol would be able to mitigate from
78% to 111% of gasoline emissions, instead of 59% to 91% as originally
reported in the US-EPA. In order to calculate actual and consistent N2O
emissions, it is also important to make field measurements (including
root:shoot ratios) for sugarcane crop.
Sugarcane mills are now being developed as biorefineries, producing
high-value co-products (i.e. modern energy carriers: biofuels and bioelectricity and bio-products) for the substitution of fossil-based products.
The main concern is how these co-products are to be properly accounted for in the GHG accounting methodologies. When the system expansion method (as per the LCA approach) is used to deal with these coproducts (mainly surplus bioelectricity), the GHG emission credits can
obviously off-set all the emissions resulting from ethanol production.
During the sugarcane milling period when there is lower water flows, this
bioelectricity can play a significant role in complementing hydroelectricity generation and in reducing fossil-fuel based marginal electricity, whilst
also contributing to GHG emissions mitigation (also see Paper V).
Therefore, the lifecycle GHG emissions of Brazilian sugarcane ethanol
are likely to reduce significantly. In the CA-CARB, credit for the excess
bagasse bioelectricity is estimated at the default value of 7 gCO2eq/MJ
(i.e. 23 kWh/tonne-cane). While the US-EPA used much higher values
of electricity credit in their scenarios, incorporating the state-of-the-art
90
Sustainability of bioethanol production in different development contexts: A systems approach
high heat and pressure technologies along with the use of cane trash and
process improvements. However, the electricity surplus from cane mills
is not yet included in the European (EU-RED and UK-RTFO) default
values. The surplus bioelectricity from sugarcane biomass could reach up
to 150 kWh/t-cane in high-pressure cogeneration plants, when considering a 50% cane trash collection for energy production (see Paper V). In
this way, the real benefits of ethanol-electricity co-production should be
established in the lifecycle GHG accounting procedures.
It is important to have the full analysis of C-stock (carbon stock in the
soils) of the land use type and associated GHG emission factors of present and projected sugarcane fields. The C-stock also varies depending
on agricultural practices (e.g. green harvesting and tillage operations).
Furthermore, the decomposition of cane residues left during the harvesting also emits. Hence, the land type and its land C-stock, and agricultural
practices should be defined, monitored and estimated carefully for determining the actual direct LUC emissions. The IPCC tier 1 approach
has been used in a large number of analyses for the evaluation of LUC
emissions (IPCC, 2006). However, the selection of appropriate parameters for sugarcane is not simple because of the agricultural practices
adopted in Brazil, including successively ratooning every 4-5 years; that is
to say, sugarcane is not replanted every year. The tillage level is not as intense as for annual crops, therefore, C-stocks are more similar with default values for perennial crops.
Besides, there are ongoing debates on the iLUC impacts of expanded
biofuels production, not only due to the conflict with food security but
also their higher GHG emissions, leading to a ‘biofuel carbon debt’. A
number of economic models, for example the GTAP computable general equilibrium model is used in the CARB and FAPRI-CARD partial
equilibrium model, which is applied in the US-EPA, have been developed for simulating the magnitude of the iLUC emissions, aiming to find
whether biofuels meet the mandatory targets or not. However, there are
still many uncertainties on the estimation of GHG emissions associated
with iLUC emissions. The use of regional models, containing the full geospatial information on land use allocation and establishment of causeeffect relations between key variables/parameters, could reduce the
iLUC emissions uncertainties. It should be noted that the Brazilian Land
Use Model (BLUM) considers the dynamics of land use change in Brazil
considering different scenarios for the estimation of land allocation and
land use changes, whilst also capturing cause-effect relationships. The
cause and effect approach adopted by the Institute of International
Trade Negotiations (ICONE) for estimating iLUC emissions with allocation methodology, which considers the dynamics of a general agricultural
and cattle raising/production on ethanol production, and the casual rela91
Doc t oral Thes is / Dilip Khat iwa da
tionship of the expansion of sugarcane field with regard to deforestation
and pastures. Additionally, the incorporation of legal restrictions such as
avoided deforestation and conservation plans and the availability of land
for sugarcane production should be properly captured in the model. In
this way, the use of a casual-descriptive approach for estimating iLUC
emissions, coupled with the national geospatial information for land allocation and land use changes could be the future direction for the calculation of indirect land use change (iLUC) GHG emissions for Brazilian
sugarcane ethanol. At the same time, the progressive improvement of
pasture yields in Brazil cannot be ignored, which releases substantial
amounts of land for the expansion of crops without effects on native
vegetation, indicating that iLUC emissions derived from the expansion
of bioenergy in Brazil is likely to be very small in the future.
In this way, this study clearly reveals uncertainties, deviations and inconsistencies involved in the accounting of Brazilian sugarcane ethanol, also
showing the methodological divergences in the regulatory schemes.
Emissions from agricultural practices, co-product bioelectricity credit,
and indirect land use change (iLUC) emissions are the main issues to be
resolved in order to obtain an improved estimate of the lifecycle GHG
emissions of the sugarcane ethanol. The adoption of actual practices in
agricultural management systems, the incorporation of technological innovation at sugarcane biorefineries for the production of high-value energy and/or non-energy co-products, and the reduction of indirect land
use (iLUC) impacts need to be further scrutinised for all biofuel pathways to achieve methodological unification throughout the globe.
92
Sustainability of bioethanol production in different development contexts: A systems approach
7 Developing the
bioethanol industr y in
ter ms of energ y security
This chapter presents how the bioethanol industry can improve the security of
energy supply in Nepal and Brazil, by exploring the complementarity of bioelectricity obtained from the optimum utilisation of residual biomass and hydropower. This chapter also discusses the alternative uses of sugarcane biomass
for second generation (2G) ethanol and/or bioelectricity production, incorporating techno-economic optimisation analysis at the bulk of autonomous ethanol distilleries in Brazil.
7.1 Power generation from residual
biomass: A complementary option to
hydroelectricity in Nepal and Brazil
Bioelectricity derived from sugarcane biomass based cogeneration systems can provide multi-benefits not least as a complement to conventional electricity generation from hydropower in Nepal and Brazil. There
is plenty of opportunity to harness untapped bioelectricity from sugarcane biomass in both cases. This would help diversify the electricity systems and enhance security of supply, whilst also reducing system vulnerability and the risks imposed by droughts. In Nepal, the grid connected
bioelectricity from sugarcane biomass can provide power to guarantee
well-functioning industries, and help local development through rural
electrification. Also in Brazil, bioelectricity can balance seasonal hydropower availability. Bioelectricity has a great potential to develop in line
with the continuous development of the ethanol industry, not only
through a more efficient use of huge amounts of bagasse, but also
through the enhancement of the biomass potential with the better utilisation of trash/waste from sugarcane fields.
Nepal and Brazil conventionally use backpressure turbines and bagassefired boilers to raise steam at 300-350oC and 20-22 bars, which provide
the heat and power needed for internal use (i.e. sugarcane milling) only.
Efficient and the-state-of-the-art cogeneration systems, which are readily
available, can drastically increase electricity generation capacity in sugar93
Doc t oral Thes is / Dilip Khat iwa da
cane mills, providing surplus electricity to the grid. The amount of surplus electricity depends on the cogeneration configuration (i.e. pressure/temperature, heat and steam consumption) and the availability of
sugarcane biomass. Paper V presents the different cogeneration configurations for surplus power and the production potential in both countries.
The study finds that the total electricity generation would be 313 GWh
with the installed capacity of 87 MW (or 36 MWaverage) in Nepal, and 93.4
TWh with the installed capacity of 19,456 MW (or 10,661 MWaverage) in
Brazil, see Table 4. It is worth noting that sugar mills in Nepal have capacities ranging from 800 – 3000 metric tons (tonnes) per day. Therefore, the size of cogeneration plants for surplus electricity varies from 5
– 19 MW, which are suitable of the off-grid or isolated power systems in
industrial corridors and rural areas.
It is necessary to opt for efficient cogeneration plants since the price of
bioelectricity production from sugarcane biomass is very cost competitive, also profitable in terms of total energy and carbon reduction costs.
But, the cost may vary depending on regional location, pricing policy, the
size of the plant, and the processing technologies. Since it has a short
gestation period with proven and well established technologies, capital
costs can be paid back within 5 years by selling surplus electricity to the
national grid.
7.2 Complementing hydroelectricity with
bioelectricity in terms of energy
security
Brazil and Nepal have significant hydropower as well as bioenergy potential. The contribution of electricity production from hydroelectricity
was the highest in both countries with the respective figure of 99% (in
Nepal) and 85% (in Brazil) in 2009. In fact, they have the highest per
capita hydro resource for hydroelectric production in the world. It
should be noted that, in the primary energy mix, the use of inefficient
traditional biomass was 87% in Nepal while Brazil has made a transition
toward modern bioenergy with only a 10% share from firewood and
over 19% from modern sugarcane bioenergy systems.
Over reliance in only one source of energy for electricity generation (i.e.
hydropower) with seasonal variations and high dependency on hydrological cycles (e.g. rain falls, drought) increases uncertainty and vulnerability
of the security of electricity supply, especially when water levels are low
in dams and reservoirs. In the dry season, the production of hydroelectricity reduces in Nepal and Brazil, which generates less amount of electricity. Therefore, diversification of the energy sources is indispensable,
94
Sustainability of bioethanol production in different development contexts: A systems approach
not only to secure energy supply but also to guarantee availability and the
optimisation of natural resources.
Table 4: Surplus bioelectricity potential in Nepal and Brazil
Parameters
Nepal
Brazil
GWh
313
93,390
MWavarage
36
10,661
Mwcrushing
87
19,456
Notes: The total installed capacity (MWcrushing or simply MW) is estimated
based on an average sugarcane crushing period in Nepal (i.e. 150 days)
and Brazil (i.e. 200 days), while the average capacity (MWaverage) is the
yearly average MW, estimated at 365 days, dividing total energy generation (i.e. MWh) by the numbers of hours (=24*365=8760) in a year.
Bioelectricity can play a significant role in complementing hydroelectricity generation and reducing the use of fossil based power generation in
Brazil at the margin and increasing the security of electricity supply in
Nepal. Installation of high pressure boilers and turbines in sugarcane
mills, replacing existing low pressure backpressure turbines could provide a window of opportunity to supply significant amounts of electricity
to the grid. Again, the dry season and the period of operation of the sugar mills coincide, the complementarity of the two sources is straight forward, facilitating the exploration of this huge untapped bioelectricity potential from bagasse and trash/waste, which is readily available in both
Nepal and Brazil.
Figure 27 depicts the trend of electricity generation by fuel types, including the potential of bioelectricity in Brazil. Sugarcane mills produced 14.1
TWh (i.e. 3% of the total electricity production) of bioelectricity from
cane-bagasse in 2009, which are mostly used to meet internal power requirements at mills. With the use of efficient high-pressure condensingcum-extraction steam turbine (CEST) cogeneration systems, surplus bioelectricity could increase up to a level of 93.4 TWh, which is 20% of the
total generation (i.e. 466.2 TWh). Meanwhile, sugarcane production has
been continuously growing at an average rate of 10.5% rate per year
since 2000, implying a parallel increase in the potential for bioelectricity
generation in the future.
In Nepal, most hydropower plants are of the run-of-the-river type. This
means that they are subject to high seasonal river flows, and cannot provide electricity in their full capacity in the dry season. Total installed capacity of electricity generation plants is also very small, thus only 56% of
95
Doc t oral Thes is / Dilip Khat iwa da
the population have access to electricity, primarily in urban areas. Nepal
can hardly afford to run thermal plants with imported fossil fuels. A lack
of infrastructure for better use of the country’s hydroelectric and biomass potential, coupled with limited financial resources is causing massive load-shedding (power outage or black-out) situations up to 16 hours
per day in the dry season. In this context, the development of the CEST
cogeneration systems in sugar mills could deliver plenty of electricity to
the grid, also coinciding with the dry season, when the nation is in major
black-out situations. For example, 313 GWh of surplus electricity could
have been sold to the national grid in 2006/07. Taking yearly average
values during the crushing period (in 150 days), electricity consumption
in the residential and industrial sectors (which represent about 83% of
the total consumption in 2006/07) were 367 GWh and 390 GWh, respectively. Thus, bioelectricity could cover about 41% of this electricity
consumption during the crushing period, see Figure 28 (left). It should
be noted that the total generation of electricity was 2051.8 GWh (in
2006/07) including 10.8% (i.e. 329 GWh) electricity imports from India.
Figure 28 (right) shows that bioelectricity could even replace the need for
costly imported electricity.
Figure 27: Electricity generation in Brazil, by source 2000–
2009.
(secondary axis shows the total hydropower generation)
Source: Ministry of Mines and Energy (MME), the Federal Government of Brazil, MME (2011). Surplus bioelectricity projection by author.
96
Sustainability of bioethanol production in different development contexts: A systems approach
The demand is drastically increasing but there is a limited source of electricity generation, which can only be changed through new investments
in generation capacity. It is important to note that total electricity consumption in the two major sectors (i.e. residential and industrial) has abnormally decreased from the year 2007-2009 due to non-availability of
electricity in the grid – both from internal production and imports. Energy shortages have led to a negative impact on socio-economic and industrial development in the country.
Figure 28: Trend of electricity consumption (residential &
industrial) with potential surplus bioelectricity
during the sugarcane crushing period (left) and
imports of electricity and potential surplus bioelectricity (right) in Nepal.
7.3 Realising the bioelectricity potential:
A discussion
In Brazil, cogeneration systems based on sugarcane biomass run at the
lowest range of unit variable cost compared to fossil based thermal systems as bagasse fuel is low-priced. Considering the optimised merit order
dispatch of electricity in the Brazilian grid in terms of the overall costs
and environmental performance, bioelectricity from cogeneration systems could represent a portion of the base-load at least during the dry
season. It is important to mention that the differentiation of electricity
production during the wet and dry seasons could add additional advantages for bioelectricity derived from sugarcane biomass in Brazil. The
size of cogeneration plants varies from 5 to 19 MW, making them suitable for distributed energy systems aimed at local electricity demand for
the increased reliability and stability of electricity systems in Nepal. Bagasse cogeneration plants for bioelectricity production takes place near
the load centres (in Brazil) and industrial corridors or densely inhabited
97
Doc t oral Thes is / Dilip Khat iwa da
rural areas in the plain land (in Nepal), implying a reduction of transmission and distribution losses. Availability of resources and efficient proven technologies provide the basis for exploring sugarcane-based bioelectricity in both cases. Short project development and implementation
time, and the opportunity to explore various plant scales, add to the attractiveness of bioelectricity as a renewable option to be explored. Bioelectricity could provide about 32% of the total available hydroelectricity
capacity (i.e. 272 MW) at the peak during the dry season in Nepal. Additionally, electricity consumption remarkably varies during the day. Bioelectricity could serve peak hours of the day, provided that there are sufficient storage facilities to store excess bagasse. If surplus bioelectricity
from domestic renewable sugarcane biomass is connected to the grid,
Nepal can save US$ 47.1 million by substituting a similar amount of imported electricity, diverting this monetary savings for national building.
The expansion of power production in the Brazilian electric system has
been stimulated through auctions promoted annually, while Nepal intends to purchase hydroelectricity from Independent Power Producers
(IPP). Even in a country such as Brazil, where the sugar-ethanol industry
has experienced continuous development from agriculture to fuel production, and is considered as an alternative transport fuel, potential synergies for bioelectricity production are only slowly being explored. This
implies lost opportunities for further increasing resource and economic
efficiency in the sugar-ethanol industry, and in the Brazilian energy system as a whole. In Nepal, improved resource efficiency in the sugarcane
based industry can significantly improve the security of electricity supply,
reduce public financial costs with fossil fuel imports, and also foster efficiency improvements in agriculture and rural development.
Some of the drawbacks of the cogeneration plants in sugarcane mills are:
the inability to deliver firm or regular power throughout the year, difficulty in collection and transportation of the sugarcane trash/residue, and
issues related to the costs for the connection and transmission and electricity prices of the grid connected surplus bioelectricity. Sugarcane production is seasonal and mills only operate 5-7 months annually, but both
storage and complementary biomass sources and synergies with other
industries ought to be considered to extend the electricity generation season. Biomass-based generation involves multiple actors which in turn
lead to more complex project finance. This could be one of the obstacles
reducing the attractiveness of bioelectricity projects. On the other hand,
the market formations for bioelectricity is also not clear in Nepal due to
insufficient regulatory conditions for receiving surplus bioelectricity from
cogeneration systems in the grid. Though the government’s plan includes
connecting excess captive power from industries to the grid, this has not
yet materialised. One of the major hurdles for realising the potential of
98
Sustainability of bioethanol production in different development contexts: A systems approach
surplus bioelectricity in Nepal is the lack of government policies, political
stability, and institutional set-up/performance. In addition, the initial investment on efficient cogeneration systems for generating surplus electricity is also high for sugar industries if no incentives are provided.
To address these obstacles, the specific characteristics of the bioelectricity segment, the multiple actors involved and their various possible constellations at different scales need to be dealt with, and reflected in policy
mechanisms. If the policy framework and incentives are there to help,
markets can be better used to promote innovative energy systems in Brazil. This approach is also valid for poor countries such as Nepal, where
market forces could be triggered in efforts towards decentralised rural
electrification. Last but not least, as international cooperation in the energy and climate agenda continues to evolve and increasingly contemplate energy security and climate gains, new opportunities arise for Brazil
and Nepal to further explore electricity from biomass and hydropower.
7.4 Optimising sugarcane biorefineries
for energy production: A technoeconomic analysis
In sugarcane biorefineries, electricity and bioethanol (i.e. first generation
‘1G’ and second generation ‘2G’) can be produced using sugarcane feedstock in different technological set-ups. The three technological options
identified and simulated in the study are: the present technology (with no
surplus electricity) and two upgraded technologies, viz. efficient cogeneration systems for electricity generation (electricity option) and second
generation ethanol through biochemical conversion of sugarcane biomass (2G ethanol option), see Paper VI and Chapter 2 for the configuration of technological options in sugarcane mills/biorefineries. The study
finds that it is worthwhile to upgrade sugarcane biorefineries for the
production of more energy services in the form of second generation
(2G) ethanol and/or bioelectricity.
Different scenarios are developed to find the conditions for optimal utilisation of residual sugarcane biomass. However, owning to the same
feedstock (i.e. bagasse and trash/waste) for bioelectricity and 2G ethanol
production, these two energy carriers may compete with each other with
respect to total system costs and lifecycle GHG emissions. This study
presents a techno-economic analysis for the bulk of sugarcane production area and upgraded sugarcane biorefineries located in the Brazilian
state of Sao Paulo (SP) using the BeWhere mixed integer and spatially
explicit model for evaluating the choice of technological options. The
entire supply chain of the electricity and biofuel production are consid99
Doc t oral Thes is / Dilip Khat iwa da
ered in the optimisation process. The trade of second generation ethanol
to the European Union (EU) is also considered. The study finds that energy prices, type of electricity substituted, biofuel support and carbon
tax, investment costs, and conversion efficiencies are the major factors
influencing the technological choice (see Paper VI for details). Some of
the key results on the reference case and influential scenarios are discussed below, also showing the main policy implications of the optimisation study.
7.4.1
Optimising energy production in the
reference scenario
In the reference scenario, in which the existing market and technological
conditions apply (including current costs and prices) it is optimal to
produce second generation (2G) ethanol in Brazil and export to the EU.
Total 1G and 2G ethanol production is 668 PJ y-1 and 301 PJ y-1 respectively while the total lifecycle GHG emissions are estimated to be 16.8
Mt.CO2eq y-1. The result indicates that 2G ethanol could amount to
2.5% of the EU transport fuel consumption in 2010, which is a significant share of contribution to the EU transport fuel mix. Figure 29
shows the share of emissions and costs along the biofuel chain. Emissions from feedstock production correspond to the largest share of
emissions along the fuel chain i.e. 66%, followed by plant emissions
(16%), and feedstock transport (11%). When it comes to costs, feedstock cost contributes only 37%. The use of ethanol in transport will
substitute gasoline and subsequently remove 56 Mt.CO2eq in Brazil and
25 Mt.CO2eq in the EU, thus resulting in 79% total emissions savings
compared to conventional fossil fuel. The study also finds that the total
cost of producing ethanol (1G and 2G) together is 0.53 US$/litre. Some
of the research highlights are as below:
Optimal to produce 2nd generation ethanol in all plants
2nd generation ethanol export contributes to 2.5% of the transport fuel share in the EU
Avoided emissions: 81 MtCO2eq y-1 (i.e. 79% savings)
Total costs: US$24.9/GJ (i.e. 0.53 US$/litre)
100
Sustainability of bioethanol production in different development contexts: A systems approach
Figure 29: Lifecycle costs (left) and emissions (right)
along the biofuel supply chain in the reference scenario.
7.4.2
Determining the impact of key
parameters: Scenario and sensitivity
analysis
Different scenarios for the two upgraded technological options, viz., bioelectricity and 2G ethanol are simulated (see Paper VI for the description of scenarios). The influencing model parameters are identified and
further scrutinised. Investment and operation costs of the 2G ethanol
option are high compared to the electricity option. The investment cost
and enzyme cost are, therefore, worth closer examination. The study examines the effect of the costs of emitting GHG emissions (i.e. carbon
tax), biofuel policy support (such as tax reduction and green certificates),
plant efficiencies, and the price or cost of energy services. Biofuel support and energy prices are applied separately in Brazil and in the EU. Bioelectricity produced in the biorefinery displaces natural gas power,
which is the main contributor of the marginal electricity generation in
Brazil. Higher gasoline price in the EU noticeably favours the export of
the 2G ethanol from Brazil. However, lower price of gasoline in the EU
allows the use of the 2G ethanol and/or bioelectricity in Brazil. The
study finds that the main parameters influencing the choice of technological options are: electricity price, set-up and operation costs, type of
marginal electricity substituted, power plant efficiency, gasoline price,
and policy instruments (i.e. biofuel support and carbon tax). It should be
noted that a few scenarios are also developed to study the choice of bioelectricity and/or 2G ethanol options within Brazil, limiting the export
of 2G ethanol in the EU. Results of different scenarios are broadly divided into two categories: (a) Market and technological impacts, viz. plant efficiency, investment and operation costs, type of substituted power, and
market price of fuel/energy, and (b) Policy impacts, i.e. biofuel support and
carbon tax. This thesis describes the effect of some of key parameters
under the following sub-headings.
101
Doc t oral Thes is / Dilip Khat iwa da
a. Market and technological impacts
In the reference scenario, marginal electricity in Brazil is natural gas
power (electricity emission factor: 0.16 kgCO2eq/MJ). Even if the marginal electricity was derived from carbon-intensive coal power (electricity emission factor: 0.28 kgCO2eq/MJ), it is optimal to produce 2G ethanol for export to the EU. In contrast, with the case of no export of 2G
ethanol to the EU (due to low transport fossil fuel price in the EU),
electricity emissions factor i.e. type of marginal or substituted electricity
would determine the choice of ethanol and/or electricity configuration,
see Figure 30 (left). For example, high electricity emission factor 0.28
kgCO2eq/MJ favours the optimal production of electricity.
Figure 30: Impact on the type of substituted electricity; expressed in emission factor (left)
and investment cost (right) without
condition of export (i.e. at the low gasoline price in the EU).
The production of 2G ethanol is still in the research and development
phase. Therefore, it is likely that the investment and operation costs
would increase in the future. The effect of an increase in the 2G ethanol set-up costs and enzyme costs are performed, keeping the investment costs of bioelectricity technology constant. Operational costs (i.e.
mainly enzyme costs) do not have a high impact until its 3-fold increase
at the reference condition. However, investment costs have a significant
role in determining the technological options with or without ethanol
exports to the EU. For example, a 25% increase in the investment cost
would prompt the selection of the electricity option if we consider the
condition of not exporting, see Figure 30 (right). Of all facilities, 108
biorefineries would select the electricity option if the investment cost of
the 2G option increases 20%.
In the reference scenario, power plant efficiency is set at 150 kWh/t
cane (i.e. 1.93 PJ/Mt cane). The technology considered is condensing102
Sustainability of bioethanol production in different development contexts: A systems approach
cum-extraction steam turbine (CEST). With the use of biomass integrated gasification combined cycle (BIG-CC) technology, electrical efficiency can be increased to more than 250 kWh/t cane (Paper V). The
study finds that if conversion efficiency is increased by 35% (i.e. 202.5
kWh/t cane), all plants are selected to optimally produce electricity, see
Figure 31.
It should be noted that biomass conversion technologies considered in
this study, viz. condensing-cum-extraction steam turbine (CEST) based
cogeneration plant for the electricity option and biochemical conversion
for the 2G ethanol option are at a different level of technological and
commercial development. CEST is commercially available whereas the
2G option is still under development. Therefore, it is important to simulate model results, considering technological improvements in terms of
systems costs and conversion efficiency. Based on the above results and
discussion on the market and technological impacts, the following research highlights can be made (also, see Paper VI):
Export is set by gasoline price in the EU: price below 50 US$/GJ, no export!
Type of biorefinery highly sensitive to electricity source (i.e. natural gas or coal) in Brazil
High 2nd generation ethanol investment cost favours the bioelectricity option
With a 35% power plant efficiency increase, all plants are selected for bioelectricity
Figure 31: Impact of power plant efficiency.
b. Policy impacts
The impacts of biofuel support and carbon tax policy instruments in
both EU and Brazil are scrutinised in various scenarios (see Paper VI).
For instance, when the investment costs of the 2G option increases by
two-fold, 5 US$/GJ biofuel support will only motivate the conversion
of 23% of the biorefineries into the 2G option, resulting in 96 PJ of
ethanol exports to the EU, see Figure 32 (left). When looking at the
impact of biofuel support in Brazil (without ethanol export) at an ele103
Doc t oral Thes is / Dilip Khat iwa da
vated electricity price of 65 US$/GJ, 3-5 US$/GJ support in terms of
incentive/subsidies or green certification, more than 90% of biorefineries would be converted according to the 2G ethanol option. However,
16.5 US$/GJ biofuel support can only convert 51% of the biorefineries
for the production of 2G ethanol when a 50% more efficient power
plant is considered. On the other hand, carbon tax does not have a significant impact until 300 US$/tCO2eq when natural gas power is considered as marginal electricity in Brazil. But, if carbon intensive fossil
based electricity (e.g. coal power) is considered as marginal electricity, a
carbon tax could play a key role in shifting 2G ethanol towards the electricity option as seen in Figure 32 (right). The study finds, in this case,
that all plants would be converted according to the electricity option at
a carbon tax of 150 US$/tCO2eq.
Figure 32: Impact of biofuel support (left) and
carbon tax (right).
In summary, the following key messages are delivered while performing
a techno-economic optimisation study on the choice of technological
improvements.
Biofuel support and higher fossil fuel price in the EU help promote the production and
export of 2nd generation ethanol from Brazil
Increased price of electricity from fossil sources will promote bioelectricity production
Technological innovation/improvement in conversion efficiency will determine the 2nd
generation ethanol and/or bioelectricity option
The study can also be further developed for identifying the optimum
size and location of the future sugarcane biorefineries for the minimisation of the total system costs and carbon costs. Different configurations
such as stand-alone and integrated/clustered, and conversion technologies, viz. thermochemical routes can also be simulated to identify suitable technological options. Production of sugarcane is seasonal. There is
also scope for utilizing other agricultural residues, e.g. rice husk and
wheat straw, in synergy with sugarcane biorefinery for the optimal production of energy services.
104
Sustainability of bioethanol production in different development contexts: A systems approach
8 Conclusions
This chapter summarises the results of the sustainability assessment of bioethanol, turning to the main three key questions that were asked at the beginning, as
a way of putting the analysis into perspective and drawing conclusions and an
outlook for future work.
8.1 Conclusions
This dissertation shows that sugarcane-molasses bioethanol production
is sustainable in Nepal in terms of energy and climate gains. The use of
bioethanol as a transport fuel leads to direct socio-economic and environmental benefits such as the replacement of gasoline fuel, saving of
hard foreign currency, enhancement of energy security, diversification of
energy products, and improvement of local air quality in urban cities. In
spite of the international debate on biofuels, the study finds that bioethanol production in Nepal does not pose any immediate threats to food
security.
The fossil fuel required to produce 1 litre of molasses-based bioethanol
(MOE) is 2.84 MJ, giving a good energy yield ratio (7.47). Thus, bioethanol production is energy efficient in terms of the amount of fossil fuel
used to produce it. Moreover, low quality biomass feedstock i.e. molasses is converted into a high quality modern renewable transport fuel.
While, the total lifecycle emissions saving is 77% compared to conventional gasoline. Nepal can produce 18 million litres of bioethanol annually, and savings of US$ 10 million could be possible through the implementation of the E20 blend in the Kathmandu Valley to replace conventional gasoline. Besides, political and institutional concerns such as mandatory bioethanol blends and incentives/subsidies, coordination amongst
concerned stakeholders should be addressed for the production and
commercialisation of bioethanol. The insight provided using the example
of Nepal could also motivate the assessment and production of bioethanol in other low-income countries.
This thesis has also identified a number of opportunities for improvements to the energy and climate gains along the bioethanol production
chain in Nepal. Improvements can be achieved through: (a) the improvement in cane yields, with the help of the modernisation of agricultural practices, (b) cane bagasse and trash/waste being used efficiently to
105
Doc t oral Thes is / Dilip Khat iwa da
generate bioelectricity, and (c) the technological upgrading and optimisation of industrial operations. However, it is difficult to compare and
benchmark these improvements with similar studies carried out for accounting GHG balances elsewhere due to a lack of methodological coherence in evaluating bioethanol production globally.
This dissertation finds that there are methodological divergences in accounting the lifecycle GHG emissions of the mature Brazilian sugarcane
ethanol in the European and American regulations. The federal Renewable Fuel Standard (US-EPA) and the Low Carbon Fuel Standard of the
California Air Resources Board (CA-CARB) in the US vary significantly
among themselves and in relation to the European regulatory schemes.
Key methodological issues are agricultural practices (mainly soil N2O
emissions), factory operations (co-product surplus bioelectricity credit.),
and direct and indirect land use change (LUC & iLUC) impacts. When
developing comprehensive methodologies for GHG accounting and determining the long-term GHG reduction targets from Brazilian sugarcane ethanol, it is important to incorporate the trend of agricultural practices and the future direction of technological development in farms and
sugarcane mills. Mechanised harvesting (with trash recovery), and the
deployment of improved modes of transport system can contribute to
reduced lifecycle GHG emissions. Additionally, sugarcane mills are now
being converted into biorefineries, producing high-value bio-products
for substitution of fossil-based products, thereby mitigating GHG emissions.
In the context of unifying the GHG accounting methodologies, the
study suggests adopting actual practices in agricultural cultivation, fuel
production, and distribution and transportation of the sugarcane ethanol
chain in Brazil, taking account of the existing harvesting methods i.e.
percentage shares of mechanised systems, green harvesting, and percentage recovery of trash from the field, soil types, etc. Most importantly, the
amount of surplus bioelectricity co-produced in the sugarcane mills from
the current state-of-the-art cogeneration technologies should be properly
accounted for in all regulations. It is also worthwhile to seek a broader
participation of individual biofuel producers/suppliers in transparent and
accurate GHG reporting systems, while promoting and motivating them
to produce low-carbon fuel. It should be noted that there are still huge
discrepancies for accounting GHG balances for commercial and mature
Brazilian sugarcane ethanol. Other potential biofuel pathways obviously
also need further attention when it comes to GHG accounting methodologies to evaluate their full contributions to climate mitigation.
With harmonising agricultural practices (agricultural inputs and crop
management) for N2O emissions, fuel production (including the amount
106
Sustainability of bioethanol production in different development contexts: A systems approach
of surplus bioelectricity), and data on conversion of carbon stocks, we
can move forward to realising a common ground for estimating GHG
emissions. With regards to emissions related to indirect land use change
(iLUC), the modelling approach should represent local domestic scenarios and land use change pattern for the production of sugarcane ethanol,
combined with the cause-effect relationship originated from its supply
and demand.
In relation to developing the bioethanol industry in terms of energy security and the diversification of energy products, this dissertation shows
that there are plenty of biomass resources to produce more energy services when sugarcane mills are upgraded to biorefineries. The complementarity between hydroelectricity and bioelectricity from sugarcane biomass-based cogeneration plants can be achieved in Nepal and Brazil
when the surplus sugarcane biomass is efficiently utilised. The study
finds that the total electricity generation would be 313 GWh with the installed capacity of 87 MW in Nepal, 93.4 TWh with the installed capacity
of 19,456 MW in Brazil, contributing significant shares in their respective
national electricity mixes. This would help create diversification in energy
systems and enhance security of supply, also minimising possible risks
from droughts and lower water flows or increased price of fossil fuels or
cut in importation of fossil fuels for thermal power plants.
Benefits derived from the exploration of surplus bioelectricity potential
are directly linked to the prosperity of nations in terms of income, reliability, socio-economic development and standard of living, and GHG
emission reduction. In addition, bioelectricity could become a natural
hedge for sugar industries when they face financial challenges, for example, with the low price of sugar or ethanol. Improved resource efficiency
in the sugarcane based industry can significantly promote the security of
electricity supply, reduce public financial costs with fossil fuel imports,
and also foster efficiency improvements in agriculture and rural development. In Nepal, the grid connected bioelectricity from sugarcane biomass can provide power for operating industries, and also promote local
development through rural electrification. In Brazil, the biomass potential can be further enhanced through a better utilisation of the residues in
the sugar-ethanol production to balance hydropower availability. Some
of the drawbacks of efficient cogeneration plants such as a lack of delivering firm or reliable power, difficulty in collection and transportation of
trash/residues, and issues related to the costs/prices of the grid connected bioelectricity can be addressed with the provisions of appropriate policy and regulatory framework e.g. government support/incentives and
proper institutional arrangement with the involvement of multiple actors,
also creating synergies with other industries.
107
Doc t oral Thes is / Dilip Khat iwa da
While analysing the alternative uses of sugarcane biomass for second
generation (2G) ethanol and/or bioelectricity production in existing
sugarcane mills located in the state of Sao Paulo in Brazil, the study
finds that in the context of the existing market and technological conditions, it is optimal to produce second generation (2G) ethanol in the upgraded sugarcane biorefineries in Brazil and export to the EU. 2G ethanol would contribute 2.5% of the EU transport fuel in 2010. Market and
technological factors such as energy prices, plant efficiency and costs,
type of substituted electricity, and policy instruments such as carbon tax
and biofuel support are found to be the factors that most influence the
choice of technology, hence 2G ethanol and/or bioelectricity. The study
finds that the generation of bioelectricity would be optimal when a
combination of carbon-intensive electricity and a high emission tax is
applied in Brazil.
8.2 Future work
The development of lifecycle case studies for sustainability assessment,
and the optimisation of crops and agricultural residues-based commercial
bioenergy carriers (i.e. bioelectricity and bioethanol) are important for
many developing countries. This thesis primarily focused on energy and
GHG balances. The lifecycle economic and social assessment and the
optimisation of relevant sustainability indicators would be interesting to
investigate further. In this regard, case studies on the lifecycle assessment
and the sustainability of biofuel production in African LDCs and other
developing countries should be carried out, considering climate, energy,
land use, water use, and environmental performance.
The optimisation study, as performed in Paper VI of this thesis, is primarily focused on the technological upgrading of existing sugarcane
mills, but it would be imperative to look into the new sugarcane mills as
ethanol production expands. The model can be further developed for
identifying the optimum size and location of the future sugarcane biorefineries to minimise the total system and carbon costs. Alternative configurations such as stand-alone and integrated/clustered, and conversion
technologies, viz. thermochemical routes can also be investigated/simulated to find suitable technological options. Production of sugarcane is seasonal. There is also scope for utilising other agricultural residues, e.g. rice husk and wheat straw, in synergy with sugarcane biorefinery for optimal production of energy services.
In order to allow a comparative analysis of the sustainability assessment
of biofuels production from different feedstocks across the globe, methodological coherence and unification should be established and benchmarked in the context of the evaluation of sustainable bioenergy systems
108
Sustainability of bioethanol production in different development contexts: A systems approach
for product certification, and international trade from a lifecycle perspective. This thesis has identified issues for unifying sustainability assessment criteria and this can be explored further for alternative biofuel
pathways, including their system boundaries, allocation methods, coproducts, and direct and indirect land use change (LUC and iLUC).
Last but not least, until now bioenergy and climate policies primarily focus on mitigation measures. Adaptation strategy in bioenergy production
is not straight-forward since it interlinks ecosystem services and livelihoods. Bioenergy systems should be scrutinised based on the full lifecycle GHG emissions estimation, resource utilisation, land use performances/practices, and mitigation and adaptation costs/benefits, aimed at
creating simultaneous adaptation and mitigation benefits for livelihoods
and maintaining natural ecosystem. The adaptation-mitigation linkages
may open opportunities for synergies. Bioenergy production can have
positive or negative effects on water and land resource management.
Degraded land for bioenergy production can improve soil and water
conservation. The use of second generation feedstock (i.e. agricultural
and forestry residues) for expanded bioenergy production can contribute
to climate change mitigation without compromising food production.
While harvesting energy crops, agricultural residual left on farmland is
used to maintain soil quality, thus enhancing the adaptive capacity of
soils. Adaptation actions such as the selection of robust feedstock/crop
varieties, improved water use efficiency, and the use of organic fertiliser
can contribute to mitigation. Conversion of low-value biomass into
modern energy services not only reduce GHG emissions but also have a
positive effect on adaptation. Bioelectricity could be a good complementary option for hydroelectricity, when precipitation is low in the dry season as investigated in this thesis. In the least developed countries, conversion of traditional biomass into modern energy services can offer
multiple-benefits such as improved energy security, rural development,
and human health. Trading of CDM carbon-credits can provide funds
for adaptation actions. Therefore, there is an urgency of research to investigate the inter-linkages between climate change mitigation and adaptation in relation to bioenergy production and use, and international
trade.
109
Doc t oral Thes is / Dilip Khat iwa da
110
Sustainability of bioethanol production in different development contexts: A systems approach
9 References
Abbasi, T., Abbasi, S.A., 2010. Biomass energy and the environmental
impacts associated with its production and utilization. Renewable and
Sustainable Energy Reviews 10, pp. 919-937.
Afgan, H.A., Carvalho, M.G., Hovanov, N.V., 2000. Energy system assessment with sustainability indicators. Energy Policy 28, pp. 603-612.
Afionis, S., Stringer, L.C., 2012. European Union leadership in biofuels
regulation: Europe as a normative power? Journal of Cleaner Production 32, pp. 114-123.
Agbemabiese, L., Nkomo, J., Sokona, Y., 2012. Enabling innovations in
energy access: An African perspective. Energy Policy 47, pp. 38-47.
Alam. F., Date, A., Roesfiansjah, R. Mobin, S., Moria, H., Baqui, A.,
2012. Biofuel from algae- Is it a viable alternative? Procedia Engineering 49, pp. 221-227.
Al-Hasan, M., 2003. Effect of ethanol–unleaded gasoline blends on engine performance and exhaust emission. Energy Conversion and Management 44, pp. 1547-1561.
Amigun, B., Musango, J. K., Stafford, W., 2011. Biofuels and sustainability in Africa. Renewable and Sustainable Energy Reviews 15, pp. 13601372.
Arndt, C., Benfica, R., 2011. Gender Implications of Biofuels Expansion
in Africa: The Case of Mozambique. World Development 39, pp. 16491662.
Azapagic, A., Clift, R., 1999. Life cycle assessment and multiobjective
optimisation. Journal of Cleaner Production 7, pp. 135-143.
Balat, M., Balat, H., 2009. Recent trends in global production and utilization of bio-ethanol fuel. Applied Energy 86, pp. 2273-2282.
Balat, M., Balat, H., Oz, C., 2008. Progress in bioethanol processing.
Progress in Energy and Combustion Science 34, pp. 551-573.
Batidzirai, B., Faaij, A.P.C., Smeets, E., 2006. Biomass and bioenergy
supply from Mozambique. Energy for Sustainable Development 10,
pp. 54-81.
Bird, N., Cowie, A., Cherubini, F., Jungmeier, G., 2011. Using a Life Cycle Assessment Approach to Estimate the Net Greenhouse Gas Emissions of Bioenergy. IEA Bioenergy:ExCo:2011:03.
111
Doc t oral Thes is / Dilip Khat iwa da
Black, M.J., Whittaker, C., Hosseini, S.A., Diaz-Chavez, R., Woods, J.,
Murphy, R.J., 2011. Life Cycle Assessment and sustainability methodologies for assessing industrial crops, processes and end products. Industrial Crops and Products 34, pp. 1332-1339.
Börjesson, P., Tufvesson, L.M., 2011. Agricultural crop-based biofuels –
resource efficiency and environmental performance including direct
land use changes. Journal of Cleaner Production 19, pp. 108-120.
Brennan, L., Ownede, P., 2010. Biofuels from microalgae—A review of
technologies for production, processing, and extractions of biofuels
and co-products. Renewable and Sustainable Energy Reviews 14, pp.
557-577.
Buchholz, T., Luzadis, A.V., Volk, T.A., 2009. Sustainability criteria for
bioenergy systems: results from an expert survey. Journal of cleaner
production 17, S86-S98.
Burgess, A.A., Brennan, D.J., 2001. Application of life cycle assessment
to chemical processes. Chemical Engineering Science 56, pp. 25892604.
Buytaert, V., Muys, B., Devriendt, N., Pelkmans, L., Kretzschmar, J.G.,
Samson, R., 2011. Towards integrated sustainability assessment for energetic use of biomass: A state of the art evaluation of assessment
tools. Renewable and Sustainable Energy Reviews 15, pp. 3918-3933.
CARB, 2009. Staff Report: Detailed California-Modified GREET Pathway for Brazilian Sugar Cane Ethanol, Version 2.2. Stationary Source
Division. Release Date: July 20, 2009. Available at
http://www.arb.ca.gov/fuels/lcfs/072009lcfs_sugarcane_etoh.pdf [accessed on 10 February 2013].
Cardona, C.A., Sanchez, O.J., 2007. Fuel ethanol production: Process design trends and integration opportunities. Bioresource Technology 99,
pp. 2415-2457.
Carrera, D.G., Mack A., 2010. Sustainability assessment of energy technologies via social indicators: Results of a survey among European energy experts. Energy Policy 38, pp. 1030-1039.
Cherubini, F., 2010a. GHG balances of bioenergy systems – overview of
key steps in the production chain and methodological concerns. Renewable Energy 35, pp. 1565-1573.
Cherubini, F., 2010b. The biorefinery concept: Using biomass instead of
oil for producing energy and chemicals. Energy Conversion and Management 51, pp. 1412-1421.
Cherubini, F., Bird, N. D., Cowie, A., Jungmeier, G., Schlamadinger, B.,
Gallasch, S.W., 2009. Energy- and greenhouse gas-based LCA of biofuel and bioenergy systems: Key issues, ranges and recommendations.
Resources, Conservation and Recycling 53, pp. 434-447.
112
Sustainability of bioethanol production in different development contexts: A systems approach
Cherubini, F., Strømman, A.H., 2011. Life cycle assessment of bioenergy
systems: State of the art and future challenges. Bioresource Technology
102, pp. 437-451.
Cherubini, F., Ulgiati, S., 2010. Crop residues as raw materials for biorefinery systems – A LCA case study. Applied Energy 87, pp. 47-57.
Costa, R.C., Sodre, J.R., 2010. Hydrous ethanol vs. gasoline-ethanol
blend: Engine performance and emissions. Fuel 89, pp. 287-293.
Cramer, J. et al., 2006, Testing Framework for Sustainable Biomass, Final
Report from the Project Group, Sustainable production of biomass,
Creative Energy, Energy Transition, Netherlands. Available at
http://www.lowcvp.org.uk/assets/reports/070427-CramerFinalReport_EN.pdf [accessed on 10 April 2013].
CTC, 2012. Sugar Cane Technology Center (CTC: Portuguese acronym
for Centro de Tecnologia Canavieira). Personal communication with
Mr. Luiz Antonio Dias Paes (27 June 2012), Manager at CTC, Piracicaba, Brazil.
Curran, M.A., 2008. Development of life cycle assessment methodology:
A focus on co-product allocation. PhD Thesis, Erasmus University,
Rotterdam, the Netherlands.
Dai, D., Hu, Z., Pu, G., Li, H., Wang, C., 2006. Energy efficiency and
potentials of cassava fuel ethanol in Guangxi region of China. Energy
Conversion and Management 47, pp. 1686-1699.
Dale, V.H., Efroymson, R.A., Kline, K.L., Langholtz, M.H., Leiby, P.N.,
Oladosu, G.A., Davis, M.R., Downing, M.E., Hilliard, M.R., 2013. Indicators for assessing socioeconomic sustainability of bioenergy systems: A short list of practical measures. Ecological Indicators 26, pp.
87-102.
Demirbas, A., 2007. Progress and recent trends in biofuels. Progress in
Energy and Combustion Science 33, pp. 1-18.
Demirbas, A., 2008. Biofuels sources, biofuel policy, biofuel economy
and global biofuel projections. Energy Conversion and Management
49, pp. 2106-2116.
DETEC, 2004. Sustainability assessment Conceptual framework and
basic methodology. Department of Environment, Transport, Energy
and Communications (DETEC), Federal Office for Spatial Development ARE (2004), Zurich, Switzerland.
Diaz-Chavez, R.A., 2011.Assessing biofuels: Aiming for sustainable development or complying with the market? Energy Policy 39, pp. 57635769.
Dornburg, V., Faaij, A., 2001. Efficiency and economy of wood-fired biomass energy systems in relation to scale regarding heat and power
113
Doc t oral Thes is / Dilip Khat iwa da
generation using combustion and gasification technologies. Biomass
and Bioenergy 21, pp. 91-108.
DSD, 2005. Dutch Sustainable Development Group (DSD). Feasibility
study on an effective and sustainable bio-ethanol production program
by least developed countries as alternative to cane sugar export. Ministry of Agriculture, Nature and Food Quality (LNV), The Hague, the
Netherlands.
EC, 2009a. Directive 2009/28/EC of the European Parliament and of
the Council of 23 April 2009 on the promotion of the use of energy
from renewable sources and amending and subsequently repealing Directives 2001/77/EC and 2003/ 30/EC.
EC, 2009b. Directive 2009/30/EC of the European Parliament and of
the Council of 23 April 2009 amending Directive 98/70/EC as regards
the specification of petrol, diesel and gas–oil and introducing a mechanism to monitor and reduce greenhouse gas emissions and amending
Council Directive 1999/32/EC as regards the specification of fuel used
by inland waterway vessels and repealing Directive 93/12/EEC.
EC, 2012. European Commission (EC). Renewable Energy: Biofuels Sustainability schemes. Available at
http://ec.europa.eu/energy/renewables/biofuels/sustainability_schem
es_en.htm [accessed on 25 February 2013].
Ekvall, T., Finnveden, G., 2001. Allocation in ISO 14041—a critical review. Journal of Cleaner Production 9, pp. 197-208.
Elghali. L., Cliff, L.R., Sinclair, P., Panoutsou, C., Bauen, A., 2007. Developing a sustainability framework for the assessment of bioenergy
systems. Energy Policy 35, pp. 6075-6083.
EPA, 2010a. United States Environmental Protection Agency
(EPA).Renewable Fuel Standard Program (RFS2), Regulatory Impact
Analysis. Assessment and Standards Division, Office of Transport and
Air Quality U.S. Environmental Protection Agency. EPA-420-R-10006, February 2010.
EPA, 2010b. Environmental Protection Agency (EPA), US. Updated
Renewable Fuels Standard (RFS2), Final Rule Making (FRM) - Life Cycle Assessment, public docket (RFS2-FRM-LCA-Docket-Materials).
Escobar, J.C., Lora, E.S., Venturini, O.J., Yanez, E.E., Castillo E.F.,
Almazan, O., 2009. Biofuels: Environment, technology and food security. Renewable and Sustainable Energy Reviews 13, pp. 1275-1287.
EUBIA, 2005. Creating markets for renewable energy Technologies EU
RES Technology Marketing Campaign - Bioethanol production and
use. European Biomass Industry Association (EUBIA).
Evans, A., Strezov, V., Evan, T.J., 2009. Assessment of sustainability indicators for renewable energy technologies. Renewable and Sustainable
Energy Reviews 13. pp. 1082-1088.
114
Sustainability of bioethanol production in different development contexts: A systems approach
Faaij, A.P.C., 2006. Bio-energy in Europe: changing technology choices.
Energy Policy 34, pp. 322-342.
FAO, 2010. Bioenergy and Food Security. The BEFS (Bioenergy and
Food Security) analysis for Tanzania. The Bioenergy and Food Security
Project, Food and Agriculture Organization of the United Nations
(FAO).
FAO, 2011a. Food and Agricultural Organization (FAO), 2011. Core Indicators on Bioenergy and Food Security. Available at
http://www.fao.org/bioenergy/foodsecurity/befsci/69197/en/ [accessed on 12 February 2013].
FAO, 2011b. Food and Agricultural Organization (FAO), 2011. BEFSCI
brief: Good Socio-Economic Practices in Modern Bioenergy Production – Minimizing Risks and Increasing Opportunities for Food Security. Available at http://www.fao.org/bioenergy/314780860de0873f5ca89c49c2d43fbd9cb1f7.pdf [accessed on January 10,
2013].
Farrell, A.E., Plevin, R.J., Turner, B.T., Jones, A.D., O’Hare, M., Kammen, D.M., 2006. Ethanol Can Contribute to Energy and Environmental Goals. Science 311, pp. 506-508.
Fernando, S., Adhikari, S., Chandrapal C., Murali, N., 2006. Biorefineries:
current status, challenges and future direction, Energy and Fuel 20, pp.
1727-1737.
García, C.A., Fuentes, A., Hennecke, A., Riegelhaupt. E., Manzini, F.,
Masera, O., 2011.Life-cycle greenhouse gas emissions and energy balances of sugarcane ethanol production in Mexico. Applied Energy 88,
pp. 2088-2097.
Gasparatos, A., Lehtonen, M., Stromberg, P., 2013. Do we need a unified appraisal framework to synthesize biofuel impacts? Biomass and
Bioenergy 50, pp. 75-80.
GBEP, 2011. The Global Bioenergy Partnership Sustainability Indicators
for Bioenergy, first edition (December 2011). GBEP Secretariat, FAO,
Environment, Climate Change and Bioenergy Division, Rome, Italy.
German, L., Schoneveld, G., 2012. A review of social sustainability considerations among EU-approved voluntary schemes for biofuels, with
implications for rural livelihoods. Energy Policy 51, pp. 765-778.
Ghatak, H.R., 2011. Biorefineries from the perspective of sustainability:
Feedstocks, products, and processes. Renewable and Sustainable Energy Reviews 15, pp. 4042-4052.
Gheewala, S.H., Bonnet, S., Prueksakorn, K., Nilsalab, P., 2011. Sustainability Assessment of a Biorefinery Complex in Thailand. Sustainability
3, pp. 518-530.
115
Doc t oral Thes is / Dilip Khat iwa da
Gnansounou, E., 2011. Assessing the sustainability of biofuels: A logicbased model. Energy 36, pp. 2089-2096.
Gnansounou, E., Bedniaguine, D., Dauriat, A., 2005. Promoting bioethanol production through clean development mechanism: findings and
lessons learnt from ASIATIC project. In: Proceedings of 7th IAEE
European energy conference, Bergen, Norway; August 2005.
Gnansounou, E., Dauriat, A., Villegas, J., Panichelli, L., 2009. Life cycle
assessment of biofuels: Energy and greenhouse gas balances. Bioresource Technology 100, pp. 4919-4930.
Goh, C.S.., Lee, K.T., 2010. A visionary and conceptual macroalgaebased third-generation bioethanol (TGB) biorefinery in Sabah, Malaysia
as an underlay for renewable and sustainable development. Renewable
and sustainable energy Reviews 14, pp. 842-848.
Goldemberg, J., Coelho, S.T., Guardabassi, P., 2008. The sustainability
of ethanol production from sugarcane. Energy Policy 36, pp. 20862097.
Goldemberg, J., Coelho, S.T., Nastari, P.N., Lucon, O., 2004. Ethanol
learning curve - the Brazilian experience. Biomass and Bioenergy 26,
pp. 301-304.
Gopal, A.R., Kammen, D.M., 2009. Molasses for ethanol: the economic
and environmental impacts of a new pathway for the lifecycle greenhouse gas analysis of sugarcane ethanol. Environmental Research Letters 4, pp. 1-5.
Grisi, E.F., Yusta, J.M., Khodr, H.M., 2011. A short-term scheduling for
the optimal operation of biorefineries. Energy Conversion and Management 52, pp. 447-456.
Guinée, J.B., 2002. Handbook on life cycle assessment—an operational
guide to the ISO standards. Dordrecht: Kluwer Academic Publishers.
Guinée, J.B., Heijungs, R., Huppes, G., 2004. Economic allocation: examples and derived decision tree. International Journal of Life Cycle
Assessment 9, pp. 23-33.
Gunningham, N., 2013. Managing the energy trilemma: The case of Indonesia. Energy policy 54, pp. 184-193.
Harijan, K., Memon, M., Uqaili, M.A., Mirza, U.K., 2009. Potential contribution of ethanol fuel to the transport sector of Pakistan. Renewable
and Sustainable Energy Reviews 13, pp. 291-295.
Hayati, D., Ranjbar, Z., Karami, E., 2010. Measuring Agricultural Sustainability. Biodiversity, Biofuels, Agroforestry and Conservation Agriculture, Sustainable Agriculture Reviews 5, pp. 73-100.
Hediger, W., 2000. Sustainable development and social welfare. Ecological Economics 32, pp. 481-492.
116
Sustainability of bioethanol production in different development contexts: A systems approach
Heijungs, R., Guinée, J.B., 2007. Allocation and ‘what-if’ scenarios in life
cycle assessment of waste management systems. Waste Management
27, pp. 997-1005.
Heijungs, R., Huppes, G., Guinée, J.B., 2010. Life cycle assessment and
sustainability analysis of products, materials and technologies. Toward
a scientific framework for sustainability life cycle analysis. Polymer
Degradation and Stability 95, pp. 422-428.
Heller, M.C., Keoleian, G.A., 2003. Assessing the sustainability of the US
food system: a life cycle perspective. Agricultural systems 76, pp. 10071041.
Hira, A., 2011. Sugar rush: Prospects for a global ethanol market. Energy
Policy 39, pp. 6925-6935.
Hoefnagels, R., Smeets, E., Faaij, A., 2010. Greenhouse gas footprints of
different biofuel production systems. Renewable and Sustainable Energy Reviews 14, pp. 1661-1694.
Hunkeler, D., Rebitzer, G., 2005. The future of lice cycle assessment. International Journal of Life Cycle Assessment 10, pp. 305-308.
IAEA, facts sheet. IAEA-Fact Sheets. Indicators for sustainable energy
development. International Atomic Energy Agency (IAEA).
http://www.iaea.org/Publications/Factsheets/English/indicators.pdf
IEA Bioenergy, 2010. IEA Bioenergy Task 42 Biorefinery. Available at
http://www.biorefinery.nl/fileadmin/biorefinery/docs/Brochure_Tot
aal_definitief_HR_opt.pdf [accessed on 10 April 2013].
IEA, 2004. Biofuels for transport: an international perspective. International Energy Agency (IEA), Paris.
IEA, 2011. Technology Roadmap: Biofuels for Transport. International
Energy Agency (IEA), Paris.
IEA, 2012. World Energy Outlook 2012. International Energy Agency
(OECD/IEA), Paris.
IPCC, 2006, Intergovernmental Panel on Climate Change (IPCC) Guidelines for National Greenhouse Gas Inventories, prepared by the National Greenhouse Gas Inventories Programme, Eggleston S., Buendia
L., Miwa K., Ngara T. and Tanabe K. (eds), IGES, Japan.
IPCC, 2011. Renewable Energy Sources and Climate Change Mitigation.
Special Report of the Intergovernmental Panel on Climate Change
(IPCC). Cambridge University Press, Cambridge, UK.
ISO, 2006a. International Standard ISO 14040: Environmental management - Life cycle assessment – Principles and framework. International
Organization for Standardization (ISO), Geneva, Switzerland.
ISO, 2006b. International Standard ISO 14044: Environmental management - Life cycle assessment - Requirements and guidelines. International Organization for Standardization (ISO), Geneva, Switzerland.
117
Doc t oral Thes is / Dilip Khat iwa da
Janssen, R., Rutz, D.D., 2011. Sustainability of biofuels in Latin America:
Risks and opportunities. Energy Policy 39, pp. 5717-5725.
Kates, W.K., Parris, T.M., Leiserowitz, A.A., 2005. What is sustainable
development? Goals, indicators, values and practice. Environment: Science and Policy for Sustainable Development 47, pp. 8-21.
Khatiwada, D., 2010. Assessing the sustainability of bioethanol production in Nepal. Licentiate Thesis, Department of Energy Technology,
KTH - Royal Institute of Technology, Stockholm, Sweden.
Khatiwada, D., and Silveira, S., 2009. Net energy balance of molasses
based ethanol: the case of Nepal. Renewable and Sustainable Energy
Reviews 13, pp. 2515-2524.
Khatiwada, D., Silveira S., 2011. Greenhouse gas balances of molasses
based ethanol in Nepal. Journal of Cleaner Production 19, pp. 14711485.
Klöpffer W., 2008. Life cycle sustainability assessment of products. International Journal of Life Cycle Assessment 13, pp. 89-94.
Koponen, K., Soimakallio, S., Tsupari, E., Thun, R., Antikainen, R.,
2013. GHG emission performance of various liquid transportation biofuels in Finland in accordance with the EU sustainability criteria. Applied Energy 102, pp. 440-448.
Kruyt, B., van Vuuren D.P., de Vries H.J.M, Groenenberg H., 2009. Indicators for energy security. Energy Policy 37, pp. 2166-2181.
Kumar, S., Singh, N., Prasad, R., 2010. Anhydrous ethanol: A renewable
source of energy. Renewable and Sustainable Energy Reviews 14, pp.
1830-1844.
Larson, E.D., 2006. A review of life-cycle analysis studies on liquid biofuel systems for the transport sector. Energy for Sustainable Development 10, pp. 109-126.
Leduc, S., 2009. Development of an Optimization Model for the Location of Biofuel Production Plants. Doctoral Thesis, Luleå University of
Technology, Luleå. Sweden.
Leduc, S., Wetterlund, E., Dotzauer, E., Kindermann, G., 2012. CHP or
biofuel production in Europe? Energy Procedia 20, pp. 40-49.
Liu, B., Wang, F., Zhang, B., Bi, J., 2013. Energy balance and GHG
emissions of cassava-based fuel ethanol using different planting modes
in China. Energy Policy 56, pp. 210-220.
Lucia, L. D., 2010. External governance and the EU policy for sustainable biofuels, the case of Mozambique. Energy Policy 38, pp. 73957403.
Macedo, I.C., Seabra, J.E.A., Silva, J.E.A.R., 2008. Greenhouse gases
emissions in the production and use of ethanol from sugarcane in Bra-
118
Sustainability of bioethanol production in different development contexts: A systems approach
zil: the 2005/2006 averages and a prediction for 2020. Biomass Bioenergy 32, pp. 582-595.
McBride, A.C. et al., 2011. Indicators to support environmental sustainability of bioenergy systems. Ecological Indicators 11, pp. 1277-1289.
McCarl, B.A., Meeraus, A., Eijk, P.V.D., Bussieck, M., Dirkse, S., Steacy,
P., Nelissen, F., 2011. Mccarl Expanded Gams. User Guide Version
23.6. GAMS Development Corporation.
Menon, V., Rao, M., 2012. Trends in bioconversion of lignocellulose:
Biofuels, platform chemicals & biorefinery concept. Progress in Energy
and Combustion Science 38, pp. 522-550.
Meyar-Naimi, H., Vaez-Zadeh, S., 2012. Sustainable development based
energy policy making frameworks, a critical review. Energy Policy 43,
pp. 351-361.
MME, 2010. Ministry of Mines and Energy (MME). Brazilian energy balance - year 2009. Federal Government of Brazil.
Naik, S.N., Goud, V.V., Rout, R.K., Dalai, A.K., 2010. Production of
first and second generation biofuels: A comprehensive review, Renewable and Sustainable Energy Reviews 14, pp. 578-597.
Najafi, G., Ghobadian, B., Tavakoli, T., Yusaf, T., 2009. Potential of
bioethanol production from agricultural wastes in Iran. Renewable and
Sustainable Energy Reviews 13, pp. 1418-1427.
Natarajan, K., Leduc, S., Pelkonen, P., Tomppo, E., Dotzauer, E., 2012.
Optimal Locations for Methanol and CHP Production in Eastern Finland. Bioenergy resources 5, pp. 412-423.
Nguyen, T. L.T., Gheewala, S.H., 2008a. Life cycle assessment of fuel
ethanol from cane molasses in Thailand. International Journal of Life
Cycle Assessment 13, pp. 301-311.
Nguyen, T.L.T., Gheewala, S.H., 2008b. Fuel ethanol from cane molasses in Thailand: Environmental and cost performance. Energy Policy
36, pp. 1589-1599.
Nguyen, T.L.T., Gheewala, S.H., Garivait, S., 2007a. Full chain energy
analysis of fuel ethanol from cassava in Thailand. Environmental Science & Technology 41, pp. 4135-4142.
Nguyen, T.L.T., Gheewala, S.H., Garivait, S., 2007b. Fossil energy savings and GHG mitigation potentials of ethanol as a gasoline substitute
in Thailand. Energy Policy 35, pp. 5195-5205.
Nguyen, T.L.T., Gheewala, S.H., Garivait, S., 2007c. Energy balance and
GHG-abatement cost of cassava utilization for fuel ethanol in Thailand. Energy Policy 35, pp. 4585-4596.
Nguyen, T.L.T., Gheewala, S.H., Garivait, S., 2008. Full chain energy
analysis of fuel ethanol from cane molasses in Thailand. Applied Energy 85, pp. 722-734.
119
Doc t oral Thes is / Dilip Khat iwa da
Nguyen, T.L.T., Gheewala, S.H., Sagisaka, M., 2010. Greenhouse gas
savings potential of sugar cane bio-energy systems. Journal of Cleaner
Production 18, pp. 412-418.
Nguyen, T.L.T., Hermansen, J.E., 2012. System expansion for handling
co-products in LCA of sugar cane bio-energy systems: GHG consequences of using molasses for ethanol production. Applied Energy 89,
pp. 254-261.
Nicollier, T.C., Blanc, I., Erkman, S., 2011. Towards a global criteria
based framework for the sustainability assessment of bioethanol supply
chains Application to the Swiss dilemma: Is local produced bioethanol
more sustainable than bioethanol imported from Brazil? Ecological Indicators 11, pp. 1447-1458.
Nigam, P.S., Singh A., 2011. Production of liquid biofuels from renewable resources. Progress in Energy and Combustion Science 37, pp. 5268.
Niven, R.K., 2005. Ethanol in gasoline: environmental impacts and sustainability review article. Renewable and Sustainable Energy Reviews 9,
pp. 535-555.
NREL, 2009. National Renewable Energy Laboratory (NREL) Biomass
Research National laboratory of the US Department of Energy, Office
of Energy Efficiency and Renewable Energy. Available at
http://www.nrel.gov/biomass/biorefinery.html?print [accessed on 10
April 2013].
OECD-FAO, 2011. OECD-FAO Agricultural Outlook 2011-2020: Biofuels. The Organisation for Economic Co-operation and Development
(OECD) - Food and Agriculture Organization of the United Nation
(FAO).
Okello, C., Pindozzi, S., Faugna, S., Boccia, L., 2013. Development of
bioenergy technologies in Uganda: A review of progress. Renewable
and Sustainable Energy Reviews 18, pp. 55-63.
Owen, M., van der Plas, R., Sepp, S., 2013. Can there be energy policy in
Sub-Saharan Africa without biomass? Energy for Sustainable Development 17, pp. 146-152.
Parris, T.M., Kates, R.W., 2003. Characterizing and measuring sustainable development. Annu. Rev. Environ. Resour. 28, pp. 559-586.
Patrick, M.F., Champagne, P., Cunnigham, M.F., Whitney, R.A., 2010. A
biorefinery processing perspective: Treatment of lignocellulosic materials for the production of value-added products. Bioresource Technology 101, pp. 8915-8922.
Pennington, D., 2009. Bioenergy: Today & Tomorrow - Bringing
Knowledge To Life! Michigan State University. Available at
http://www.maes.msu.edu/upes/agtomm_2009/bioenergy.pdf
120
Sustainability of bioethanol production in different development contexts: A systems approach
Pennington, D.W. et al., 2004. Life cycle assessment Part 2: Current impact assessment practice. Environment International 30, pp. 721-739.
Phalan, B., 2009. The social and environmental impacts of biofuels in
Asia: An overview. Applied Energy 86, S21-S29.
Pohit, S., Biswas, P.K., Kumar, R., Jha, J., 2009. International experiences of ethanol as transport fuel: Policy implications for India. Energy
policy 37, pp. 5540-4548.
Prakash, R., Henham, A., Bhat, I.K., 1998, Net energy and gross pollution from bio-ethanol production. Fuel 77, pp. 1629-1633.
Purohit, P., Michaelowa, A., 2007. CDM potential of bagasse cogeneration in India. Energy Policy 35. pp. 4779-4798.
Quental, N., Lourenço, J.M., da Silva, F.N., 2011. Sustainable development policy: goals, targets and political cycles. Sustainable Development 19, pp. 15-29.
Ragauskas, A.J. et al., 2006. The Path Forward for Biofuels and Biomaterials. Science 311, pp. 484-489.
Rebitzer, G. et al., 2004. Life cycle assessment Part 1: Framework, goal
and scope definition, inventory analysis, and applications. Environment
International 30, pp. 701-720.
Remer, D., Chai, L. H., 1990. Design cost factors for scaling-up engineering equipment. Chemical Engineering Progress 86, pp. 77-82.
REN21, 2012. Renewables 2012 Global Status Report. REN21: Renewable Energy Policy Network for the 21th Century. Available at
http://ren21.net/
Renouf, M.A., Pagan, R.J., Wegener, M. J., 2013. Bio-production from
Australian sugarcane: an environmental investigation of product diversification in an agro-industry. Journal of Cleaner Production 39, pp. 8796.
Rösch, C., Skarka, J., Raab, K., Stelzer, V., 2009. Energy production
from grassland – Assessing the sustainability of different process
chains under German conditions. Biomass and Bioenergy 33, pp. 689700.
Royal Society, 2008. Sustainable biofuels: prospects and challenges.
Available at http://royalsociety.org/Sustainable-biofuels-prospectsand-challenges/[accessed on 10 January 2013].
Scarlat, N., Dallemand, J.F., 2011. Recent developments of biofuels/bioenergy sustainability certification: A global review, Energy Policy 39(3), pp. 1630-1646.
Schmidt, J., Leduc, S., Dotzauer, E., Schmid, E., 2011. Cost-effective
policy instruments for greenhouse gas emission reduction and fossil
fuel substitution through bioenergy production in Austria. Energy Policy 39, pp. 3261-3280.
121
Doc t oral Thes is / Dilip Khat iwa da
Schubert, R., Blasch, J., 2010. Sustainability standards for bioenergy—A
means to reduce climate change risks? Energy policy 38, pp. 27972805.
Seabra, J.E.A., Macedo, I.C., Chum, H.L., Faroni, C.E., Sarto, C.A.,
2011. Life cycle assessment of Brazilian sugarcane products: GHG
emissions and energy use. Biofuels, Bioproducts and Biorefining 5, pp.
519-532.
Shapouri, H., Duffield, J., McAloon, A., Wang, M., 2004. The 2001 net
energy balance of corn ethanol. US Department of Agriculture. US.
Sheehan, J.J., 2009. Biofuels and the conundrum of sustainability, 20. pp.
318-324.
Silalertruksa, T., Gheewala, H., 2009. Environmental sustainability assessment of bio-ethanol production in Thailand Energy 34, pp. 19331946.
Silveira, S., Khatiwada, D., 2010. Ethanol production and fuel substitution in Nepal—Opportunity to promote sustainable development and
climate change mitigation. Renewable and Sustainable Energy Reviews
14, pp. 1644-1652
Smeets, E., Junginger, M., Faaij, A., Walter, A., Dolzan P., 2006. Sustainability of Brazilian bio-ethanol. Copernicus Institute – Department of
Science, Technology and Society, Utrecht University, the Netherlands.
Report NWS-E-2006-110, ISBN 90-8672-012-9.
Smeets, E., Junginger, M., Faaij, A., Walter, A., Dolzan, P.,Turkenburg
W., 2008. The sustainability of Brazilian ethanol—An assessment of
the possibilities of certified production. Biomass and Bioenergy 32, pp.
781-813.
Sokona, Y., Mulugetta, Y., Gujba, H., 2012. Widening energy access in
Africa: Towards energy transition. Energy Policy 47, pp. 3-10.
Sorda, G., Banse, M., Kemfert, C., 2010. An overview of biofuel policies
across the world. Energy policy 38, pp. 6977-6988.
Sovacool, B.K., Mukherjee, I., 2011. Conceptualizing and measuring energy security: a synthesized approach. Energy 36, pp. 5343-5355.
Stamford, L., Azapagic, A., 2011. Sustainability indicators for the assessment of nuclear power. Energy 36, pp. 6037-6057.
Taylor, G., 2008. Biofuels and the biorefinery concept. Energy Policy 36,
pp. 4406-4409.
Thornley, P., Upham, P., Tomei, J., 2009. Sustainability constraints on
UK bioenergy development. Energy Policy 37, pp. 5623-5635.
Timilsina, G.R., Shrestha, A., 2011. How much hope should we have for
biofuels? Energy 36, pp. 2055-2069.
UNCSD, 2012. The Future We Want: the Rio+20 United Nations Conference on Sustainable Development (UNCSD).
122
Sustainability of bioethanol production in different development contexts: A systems approach
UNDESA, 2007. Small-scale production and use of liquid biofuels in
Sub-Saharan Africa: Perspectives for sustainable development. United
Nations Department of Economic and Social Affairs (UNDESA)
commission on sustainable development: fifteen-session 30 April-11
May 2007, New York. Background paper no. 2. DESA/DSD/2007/2.
UNDP, 2006. Human Development Report - 2006. United Nations Development Program (UNDP).
UNDP, 2011. Scaling Up Decentralized Energy Services in Nepal. United Nations Development Programme (UNDP).
UNEP, 2011a. Why a Green Economy Matters for the Least Developed
Countries. United Nations Environment Programme (UNEP).
UNEP, 2011b. Towards a Life Cycle Sustainability Assessment: Making
informed choices on products. Life Cycle Initiative, United Nations
Environment Programme (UNEP).
UNICA, 2012.Brazilian Sugarcane Industry Association (Portuguese:
União da Indústria de Cana-de-Açúcar) <www.unica.com.br>[accessed
on August 2012].
UNIDO, 2006. Energy Security in Least Developed countries. United
Nations Industrial Development Organization (UNIDO).
USEPA, 2006. Life cycle assessment: principles and practice. National
Risk Management Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency (USEPA). Available at http://www.epa.gov/nrmrl/std/lca/lca.html
Van Dam, J., Junginger, M., 2011. Striving to further harmonization of
sustainability criteria for bioenergy in Europe: Recommendations from
a stakeholder questionnaire. Energy Policy 39, pp. 4051-4066.
Van Dam, J., Junginger, M., Faaij, A., 2010. From the global efforts on
certification of bioenergy towards an integrated approach based on sustainable land use planning Renewable and Sustainable Energy Reviews,
14, pp. 2445-2472.
Van Dam, J., Junginger, M., Faaij, A., Jurgens, I., Best, G., Fritsche, U.,
2008. Overview of recent developments in sustainable biomass certification Biomass and Bioenergy 32, pp. 749-780.
Van den Wall Bake, J.D., Junginger, M., Faaij, A., Poot, T., Walter, A.,
2009. Explaining the experience curve: Cost reductions of Brazilian
ethanol from sugarcane. Biomass and Bioenergy 33, pp. 644-658.
Versteeg, S., 2007. Bioethanol production in Fiji: An environmentally
sustainable project? Evidence Based Environmental Policy and Management 1, pp. 82-106.
Von Blottnitz, H., Curran, M.A., 2007. A review of assessments conducted on bio-ethanol as a transportation fuel from a net energy,
123
Doc t oral Thes is / Dilip Khat iwa da
greenhouse gas, and environmental life cycle perspective. Journal of
Cleaner Production 15, pp. 607-619.
Waas, T., Huge, J., Verbruggen, A., Wright, T., 2011. Sustainable Development: A Bird’s Eye View. Sustainability 3, pp. 1637-1661.
Waheed, B., Khan, F., Veitch, B., 2009. Linkage-Based Frameworks for
Sustainability Assessment: Making a Case for Driving Force-PressureState-Exposure- Effect-Action (DPSEEA) Frameworks. Sustainability
1, pp. 441-463.
Walter, A., Ensinas A., 2010. Combined production of secondgeneration biofuels and electricity from sugarcane residues. Energy 35,
pp. 874-879.
WCED, 1987. Our Common Future: the World Commission on Environment and Development. Oxford University Press, Oxford.
WECS, 2010. Water and Energy Commission Secretariat (WECS). Energy Sector Synopsis Report. Government of Nepal. July 2010. Kathmandu, Nepal.
Wetterlund, E., 2010. Optimal localisation of biofuel production on a
European scale, International Institute for Applied System Analysis,
Laxenburg, Austria.
Wetterlund, E., Leduc, S., Dotzauer, E., Kindermann, G., 2012. Optimal
localisation of biofuel production on a European scale. Energy 41, pp.
462-472.
Winzer, C., 2012. Conceptualizing energy security. Energy Policy 46, pp.
36-48.
Wyman, C.E., 1994. Ethanol from lignocellulosic biomass: Technology,
economics, and opportunities. Bioresource Technology 50, pp. 3-16.
Xunmin, Q., Xiliang, Z., Shiyan, C., Qingfang, G., 2009. Energy consumption and GHG emissions of six biofuel pathways by LCA in (the)
People’s Republic of China. Applied Energy 86, S197-208.
Yan, J., Lin, T., 2009. Biofuels in Asia. Applied Energy 86 (editorial supplement), S1-S10.
Yeh, S. and Sperling, D., 2010. Low carbon fuel standards: Implementation scenarios and challenges, Energy Policy 38, pp. 6955-6965.
Zah, R., Faist, M., Reinhard, J., Birchmeier, D., 2009. Standardized and
simplified life-cycle assessment (LCA) as a driver for more sustainable
biofuels. Journal of cleaner production 17, S102-S105.
Zhou, A., Thomson, E., 2009. The development of biofuels in Asia. Applied Energy 86 (editorial supplement), S11-S20.
Zhou, Z., Jiang, H., Qin, L., 2007. Life cycle sustainability assessment of
fuels. Fuel 86, pp. 256-263.
124
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement