New concepts for biofuels in transportation (size 1.1 MB)

New concepts for biofuels in transportation (size 1.1 MB)
V T T
R E S E A R C H
N O T E S
Mikael Ohlström, Tuula Mäkinen, Juhani Laurikko &
Riitta Pipatti
New concepts for biofuels
in transportation
Biomass-based methanol production and
reduced emissions in advanced vehicles
PULP &
PAPER
Heat &
Power
BARK
BOILER
Stem
wood
WOOD
PRE
TREAT
MENT
Ba
rk
T I E D O T T E I T A
2074
Power
Steam
Wood
residues
FOREST
BIOMASS
METHANOL
SYNTHESIS
Gasoline
MeOH
from biomass
MeOH from
natural gas
V T T
PETROLEUM
Methanol
TECHNICAL RESEARCH CENTRE OF FINLAND
ESPOO 2001
VTT TIEDOTTEITA – MEDDELANDEN – RESEARCH NOTES 2074
New concepts for biofuels
in transportation
Biomass-based methanol production
and reduced emissions
in advanced vehicles
Mikael Ohlström, Tuula Mäkinen, Juhani Laurikko & Riitta Pipatti
VTT Energy
TECHNICAL RESEARCH CENTRE OF FINLAND
ESPOO 2001
ISBN 951–38–5780–8 (soft back ed.)
ISSN 1235–0605 (soft back ed.)
ISBN 951–38–5781–6 (URL: http://www.inf.vtt.fi/pdf/)
ISSN 1455–0865 (URL: http://www.inf.vtt.fi/pdf/)
Copyright © Valtion teknillinen tutkimuskeskus (VTT) 2001
JULKAISIJA – UTGIVARE – PUBLISHER
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Cover picture: Mikael Ohlström
Technical editing Leena Ukskoski
Otamedia Oy, Espoo 2001
Ohlström, Mikael, Mäkinen, Tuula, Laurikko, Juhani & Pipatti, Riitta. New concepts for biofuels
in transportation. Biomass-based methanol production and reduced emissions in advanced vehicles.
Espoo 2001. Technical Research Centre of Finland, VTT Tiedotteita – Meddelanden – Research Notes
2074. 94 p.
Keywords
biomass, biofuels, wood, liquefaction, gasification, methanol, costs, emissions, greenhouse gases, engine fuels
Abstract
In this study, new concepts for methanol and hydrogen production from wood-based
biomass were evaluated and the climate benefits that could be achieved from the use of
these fuels in advanced vehicles were estimated.
In the process concepts chosen for the techno-economic assessment, methanol or
hydrogen production is integrated to CHP production of an existing pulp mill. The
production of methanol from biomass requires a fairly advanced gasification and gas
cleaning process in order to meet the requirements of the synthesis process. The
hydrogen production process is somewhat simpler. However, the evaluation of the
hydrogen production processes was, due to priorities set in the project, based on a more
shallow evaluation.
Two methanol production concepts were selected for evaluation: methanol production
integrated to an existing pulp mill in Finland and in the Far East. Performance and costs
of corresponding hydrogen production were also estimated roughly for the Finnish case.
The fast growth of wood would allow higher capacities for fuel production in the Far
East than in Europe. The capacities were selected based on the availability of the raw
material at a moderate price. In the Finnish case (fuel input 100 MW) the raw material
was forest residues (pine) and in the Far East case (500 MW) short rotation coppices
(eucalyptus). The methanol production would be 83 400 t/a in the Finnish case and
439 400 t/a in the Far East case. The production costs in the Finnish case were estimated
at around 16 EUR/GJ methanol. In the Far East case the methanol production costs were
lower, approximately 10 EUR/GJ methanol. Recently, the world market price of
methanol has been about 4.7 EUR/GJ. The scale of the plant has a considerable effect
on the fuel production costs. Currently, the largest natural gas based methanol plants
have a capacity of > 800 000 t methanol/a.
By combining the fuel, power, and heat production a high total efficiency can be
achieved. In this study, it was estimated that by integrating the methanol production to
the power plant of the pulp mill, the total efficiency of the methanol plant could be
increased to 67–69% (LHV). Reductions of about 20% were identified in the methanol
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production costs by utilising the existing equipment of the pulp mill. Further
improvements in the total efficiency and consequent production cost reductions could
be achieved by process optimisation (optimised gasification temperature, minimised
oxygen consumption, high carbon conversion in gasification, small hydrocarbon content
in the gasification gas, optimised methanol synthesis). Possibilities of using low-grade
waste heat in district heating would increase the total efficiency.
The greenhouse gas emissions from the use of the biomass-based methanol or hydrogen
in specified vehicle types were estimated and compared to corresponding emissions
from the use of gasoline, diesel, methanol made from natural gas, hydrogen derived
from electrolysis of water and those of electric vehicles. The estimated greenhouse gas
emissions included emissions from the production, distribution and use of the fuels in
vehicles. All the energy demand of the biomethanol and biohydrogen production
processes is met with energy produced by biomass. No CO2 emissions are therefore
allocated to the production processes as the biomass is assumed to be of sustainable
origin.
The total greenhouse gas emissions from the fuel chain (emissions from fuel production
and distribution + emissions from the use in the vehicles) are significantly lower
(approximately 80–90%) for the biomass-based methanol and hydrogen fuels than for
the other alternatives. Only battery electric vehicles using electricity produced from
biomass have emissions that are as low. Extensive use of battery-electric vehicles using
biomass electricity would, however, require even larger biomass resources, as the
energy efficiency of electricity production is lower than that of methanol production.
The implementation of biomass-based methanol and hydrogen as transportation fuels
involves barriers. The biomass resources are limited and the amount of biomass needed
for the substitution of the conventional fuels with the biofuels would be large. Estimates
on the availability of raw material (forest residues or eucalyptus) for the concepts
studied showed that the entire fuel demand of light-duty vehicles would be difficult to
meet by the concepts considered, even if the fuels were used in advanced vehicles.
The reduction in greenhouse gas emissions achievable by methanol or hydrogen
produced from forest residues in Finland, considering the limited availability of the
resources, was estimated for the years 2010–2020. The forest residue resources were
estimated to suffice for methanol or hydrogen production that would give reductions of
the order of 10–20% when used in LDVs of family car type compared to use of only
gasoline. The use of the methanol in fuel cell or hybrid-ICE vehicles was estimated to
give almost equal reductions (~15%), whereas the use in ICE-SI vehicles gave smaller
reductions (~10%). The use of hydrogen in fuel cell vehicles gave a few percentage
units higher emission reductions than methanol. In a vehicle fleet with a large share of
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urban commuter type cars using biomethanol or biohydrogen the total emissions would
be much smaller.
Methanol from biomass could also be used for MTBE production. In Finland, the whole
LDV vehicle fleet could be supplied with MTBE using methanol made from forest
residues. The emission reduction achieved would, however, be much less, only one
tenth of what could be achieved by using methanol in fuel cell or hybrid vehicles.
The cost of wood-based methanol and hydrogen production is, depending on the
concept chosen (fuel input 100–500 MWth), of the order of 2 to 4 times higher than that
of gasoline or methanol made from crude oil and natural gas. Subsidies or tax incentives
would be needed to introduce the wood-based fuels to the market.
Fuel cell vehicles will likely be introduced to the market within a few years. The market
share of the vehicles will be minor for many years, partly because of the time lags in the
renewal of the vehicle fleet. The availability of sustainable hydrogen and hydrogen
carrier fuels is scarce, and could in the long run become the main obstacle for the
success of the fuel cell vehicles. Sustainable hydrogen production technology based on
chemical or biological processes or electrolysis utilising renewable energy, or
production of hydrogen from fossil fuels combined with CO2 recovery and disposal, are
not expected to be commercial technology until the mid of the century, if even then.
Biomass-based methanol, or hydrogen, could enhance the introduction of the fuel cell
vehicles to the market before other sustainable concepts for, e.g., hydrogen production
are developed. The foreseen growth in the transportation volume and decreasing oil
resources could also increase the attractiveness of biomass-based methanol, or
hydrogen, as transportation fuels in the future. Environmental benefits are seen
especially in urban transportation, where the use of these fuels in fuel cell vehicles
could also improve the local air quality substantially.
5
Preface
Transportation is a major and fast growing contributor to greenhouse gas emissions
globally. There are many future technological options to reduce these emissions. In this
project, “New concepts for biofuels in transportation: biomass-based methanol production and reduced emissions in advanced vehicles”, new technologies for biomass-based
methanol production were identified and assessed, and the potential for reducing greenhouse gas emissions by using the methanol produced in transportation was evaluated.
The production of hydrogen from biomass and its use in fuel cell vehicles was also
studied, but more coarsely.
The work was carried out at VTT Energy and funded by the National Technology
Agency of Finland (Tekes), the Finnish Ministry of Trade and Industry, Fortum Oil and
Gas, Toyota Motor Europe and VTT Energy.
The work of the project was guided by a steering group, which comprised members
from all funding organisations and companies. The chairman of the steering group was
Mr Jukka-Pekka Nieminen of Fortum Power and Heat. The other members were Mrs
Raija Pikku-Pyhältö (1998–1999) and Mrs Sirpa Salo-Asikainen (2000) of Tekes, Mrs
Teija Lahti-Nuuttila (1998–1999) and Mr Erkki Eskola (1999–2000) of the Finnish
Ministry of Trade and Industry, Mr Markku Laurila of Fortum Oil and Gas, Mr Arata
Fukada (1998), Dr Muriel Desaeger, (1999–2000) and Dr Mikako Le Lay (1999–2000)
of Toyota Motor Europe, and Prof. Kai Sipilä, Dr Riitta Pipatti and Ms Tuula Mäkinen
of VTT Energy.
The report was written by Mikael Ohlström (fuel chain greenhouse gas emissions and
scenarios for biomethanol and hydrogen use, Ch. 3 and Ch. 4)), Tuula Mäkinen (methanol/hydrogen production, Ch. 2), Dr Juhani Laurikko (vehicle emissions, Ch. 3.3) and
Dr Riitta Pipatti (introduction, Ch. 1, global biomass potentials, Ch. 4.1.2, conclusions,
Ch. 5) of VTT Energy. Dr Pekka Simell is acknowledged for his help in preparing the
state-of-the-art review of biomass gasification and methanol synthesis. Ms Taru Palosuo
is acknowledged for her help in the estimation on the global biomass potentials and
emissions from eucalyptus plantations. Linde AG is acknowledged for valuable discussions and information about methanol production technology.
Espoo, October 2000
Authors
6
Contents
Abstract ........................................................................................................................... 3
Preface ............................................................................................................................. 6
List of symbols................................................................................................................. 9
1. Introduction ................................................................................................................ 11
2. Methanol production from wood ............................................................................... 15
2.1 Methanol production processes ........................................................................ 15
2.2 Gasification of biomass .................................................................................... 16
2.2.1 Gasification reactors ............................................................................. 16
2.2.2 Gas cleaning.......................................................................................... 19
2.3 Methanol synthesis ........................................................................................... 20
2.3.1 Reactions............................................................................................... 20
2.3.2 Reactors................................................................................................. 21
2.4 Integration of gasification to methanol synthesis ............................................. 24
2.5 Performance and costs of wood-based methanol processes ............................. 25
2.6 Performance of wood-based methanol process integrated to CHP production 27
2.7 Costs of wood-based methanol process integrated to CHP production............ 32
3. Greenhouse gas emissions for selected fuel production and use chains .................... 36
3.1 Emissions from fuel production........................................................................ 37
3.1.1 Methanol production from natural gas.................................................. 37
3.1.2 Methanol production from wood-based biomass.................................. 39
3.1.2.1 The production chains............................................................. 39
3.1.2.2 Emissions from the fuel supply chains ................................... 41
3.1.2.3 Emissions from the methanol production integrated to
the pulp mill............................................................................ 44
3.1.3 Gasoline and diesel production from crude oil ..................................... 45
3.1.4 Hydrogen production from biomass ..................................................... 46
3.2 Local distribution.............................................................................................. 47
3.3 Use in vehicles.................................................................................................. 49
3.3.1 Vehicles................................................................................................. 49
3.3.2 Powertrains ........................................................................................... 50
3.3.3 Fuels...................................................................................................... 50
3.3.4 Energy consumption ............................................................................. 51
3.3.5 Emissions .............................................................................................. 52
3.4 Fuel chain GHG emissions for the selected cases ............................................ 53
3.4.1 Case 1: Reference cases (gasoline and diesel in LDVs) ....................... 54
3.4.2 Case 2: MTBE from wood-derived MeOH (gasoline in LDVs)........... 56
7
3.4.3 Case 3: MeOH (both from biomass and natural gas) in fuel cell
vehicles ................................................................................................. 57
3.4.3.1 Biomass................................................................................... 57
3.4.3.2 Natural gas .............................................................................. 58
3.4.4 Case 4: Methanol use in ICE-hybrid vehicles....................................... 59
3.4.4.1 Biomass................................................................................... 59
3.4.4.2 Natural gas .............................................................................. 61
3.4.5 Case 5: Methanol use in ICE vehicles (reference case)........................ 62
3.4.5.1 Biomass................................................................................... 62
3.4.5.2 Natural gas .............................................................................. 64
3.4.6 Case 6: Electrical vehicles (electricity produced from biomass vs.
average production) .............................................................................. 66
3.4.7 Case 7: Hydrogen use in fuel cell vehicles ........................................... 67
3.4.8 Urban buses........................................................................................... 69
3.4.9 Summary of fuel chain GHG emissions ............................................... 71
4. Scenarios for the use of biomethanol and hydrogen in vehicles ................................ 77
4.1 Biomethanol use vs. biomass potentials ........................................................... 77
4.1.1 Finland .................................................................................................. 77
4.1.2 Global.................................................................................................... 82
4.2 Production costs and implementation............................................................... 84
5. Conclusions and discussion........................................................................................ 87
References ...................................................................................................................... 91
.
8
List of symbols
CFC
CHP
CH4
Cl
CO
CO2
CO2(eq)
CTI
EU
EUR
EV
Family car
FC
FIM
GHG
GVW
GWP
HCN
HDV
HFC
HFO
HHV
H2
H2O
H2S
ICE
ICE-CI
ICE-CI/H
ICE-HYBRID
ICE-SI
ICE-SI/H
LDV
LHV
LNG
MeOH
chlorofluorocarbon
combined heat and power production
methane (see also GHG)
chlorine
carbon monoxide
carbon dioxide (see also GHG)
carbon dioxide equivalent, the sum of CO2 + CH4 + N2O weighed
by global warming potential factors over 100 years
Climate Technology Initiative
European Union
Euro (currency) (1 EUR = 5.94573 FIM)
electrical vehicle
reference car with 5 seats used in calculations (5 seats, 50 kW)
fuel cell
Finnish mark (currency) (1 FIM = 0.16819 EUR)
greenhouse gases (here mainly CO2 + CH4 + N2O)
gross vehicle weight
global warming potential
hydrogen cyanide
heavy-duty vehicle
hydrofluorocarbon
heavy fuel oil
higher heating value (calorific value)
hydrogen
water
hydrogen sulphide
internal combustion engine
internal combustion engine with compression ignition
hybrid vehicle, internal combustion engine with compression ignition combined to electrical batteries
hybrid vehicle, internal combustion engine combined to electrical
batteries
internal combustion engine with spark ignition
hybrid vehicle, internal combustion engine with spark ignition
combined to electrical batteries
light-duty vehicle
lower heating value (net calorific value)
liquefied natural gas
methanol, CH3OH
9
MEUR
MTBE
M85
M100
NG
NH3
N2O
PFC
POX
PSA
R
RFD
RFG
SF6
STM
ULEV
Urban bus
Urban commuter
95E
million Euro (see EUR)
methyl tertiary-butyl ether, an additive to gasoline
methanol fuel with 15% gasoline blended in it (85% MeOH + 15%
gasoline)
neat methanol fuel (100% MeOH)
natural gas
ammonia
nitrous oxide (see also GHG)
perfluorocarbon
partial oxidation (fuel cell type)
pressure swing adsorption
stoichiometric value in methanol synthesis, (H2 – CO2)/(CO + CO2)
reformulated diesel
reformulated gasoline (95E, 10% MTBE)
sulphur hexafluoride
steam reformer (fuel cell type)
ultra-low emission vehicle
reference bus for 50 passengers used in calculations (50 passengers,
250 kW)
reference city-car with 2 seats used in calculations (2 seats, 20 kW)
unleaded gasoline, see RFG
10
1. Introduction
The atmospheric concentrations of the so-called greenhouse gases have increased significantly since the pre-industrial time. This increase is almost entirely caused by human
activities. The increasing greenhouse gas concentrations in the atmosphere are changing
the radiative energy balance of the Earth, tending to warm and produce other changes to
the climate (IPCC 1996). The environmental impacts of the predicted global warming
are associated with great uncertainties. Sea level rise, changes in precipitation, increasing climate variability and extreme weather events are predicted. The realisation of the
predicted global warming could put the well being of both humans and the environment
at risk.
Significant anthropogenic greenhouse gases are carbon dioxide (CO2), methane (CH4)
and nitrous oxide (N2O) and some halogenated substances (e.g. chlorofluorocarbons
(CFCs), hydrofluorocarbons (HFCs) and sulphur hexafluoride (SF6)). The most important greenhouse gas is CO2, which is released to the atmosphere mainly from fossil fuel
combustion. In most industrialised countries, the CO2 emissions cause 80–90% of the
anthropogenic greenhouse gas emissions. Most of the anthropogenic CH4 and N2O
emissions come from sources that are not related to energy production or use (animal
husbandry, cultivation of agricultural soils, waste management, etc.). Small-scale combustion of biomass can emit significant amounts of CH4 due to incomplete combustion.
In larger combustion units these emissions are, however, small. The emissions of the
halogenated greenhouse gases are related to industrial processes or use of various commodities of industrial origin (e.g., refrigeration, isolation materials).
Climate change is a global environmental threat that no country can control alone. The
UN Framework Convention on Climate Change (FCCC) was signed by 165 countries in
Rio in 1992. The ultimate objective of the convention is the stabilisation of greenhouse
gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. Such a level should be achieved within a
time-frame sufficient to allow ecosystems to adapt naturally to climate change, to
ensure that food production is not threatened and to enable economic development to
proceed in a sustainable manner (UNFCCC 1992).
The concentration levels of the greenhouse gases that would lead to dangerous
interference with the climate system are not defined in the convention. The first
agreement on binding emission reduction commitments was signed in Kyoto in
December 1997. The emission reductions will at first concern only the industrialised
countries (so-called Annex I countries of the Convention) as the convention recognises
the poor nations’ right to economic development.
11
According to the Kyoto protocol the Annex I countries are required to reduce their anthropogenic carbon dioxide equivalent emissions of CO2, CH4, N2O, HFCs (hydrofluorocarbons), PFCs (perfluorocarbons) and SF6 (sulphur hexafluoride) by more than
5 per cent below the 1990 levels in the commitment period 2008 to 2012. The individual
Annex I countries are given specified emissions limitation or reduction commitments in
the protocol. The emission reduction commitment for the European Union is 8%, for
USA 7% and for Japan 6% of the base year (1990) emissions. Russia and Ukraine need
to stabilise their emissions to the 1990 level and some countries (e.g., Norway, Australia
and Iceland) are allowed to increase their emissions compared to the 1990 level
(UNFCCC 1997).
Meeting the emission reduction targets of the Kyoto Protocol will only have a small
effect on the increase of greenhouse gas concentrations in the atmosphere. The commitments of the Protocol are, however, demanding and put pressure on developing and
improving energy and other systems, and even on the economies of countries. New
tighter restraints on the emissions will also most likely be set after the commitment period of the Kyoto Protocol.
Transportation is a major contributor to greenhouse gas emissions globally. According
to the national greenhouse gas inventories of the industrialised countries, transportation
caused approximately 22% of their anthropogenic greenhouse gas emissions in 1996.
Transportation was also the fastest growing source of greenhouse gas emissions and the
second largest source of emissions after energy industries in these countries (UNFCCC
1999).
The options to reduce greenhouse gas emissions from transportation include alternative
fuels, more efficient energy utilisation in vehicles, and improved traffic arrangements
and logistics. There are many alternatives for future transportation fuels and vehicle
technologies. Fuel cell vehicles, which can convert chemical energy into electricity
without combustion technology, have a great long-term potential to reduce greenhouse
gas and also other harmful emissions from transportation. The ultimate fuel for fuel cell
vehicles is hydrogen. Hydrogen is a very light and flammable gas, and its large-scale
distribution and storage pose still many difficulties. Therefore, liquid “hydrogen
carriers”, like methanol or ethanol, are attractive, although seen by many as
intermediate fuels for fuel cell vehicles.
In order to achieve significant reductions in the greenhouse gas emissions, hydrogen or
the so-called “hydrogen carrier fuels” should be produced utilising renewable energy, or
employing production combined with carbon dioxide recovery and storage. In this study
methanol, and to some extent also hydrogen, production from wood-based raw material
is studied. Methanol can be produced via synthesis gas production and thermal gasification of biomass. The technology is known from coal gasification, and some biomass
12
gasifiers are in operation for fuel gas and power production. Ethanol can also be produced from biomass, and the processes are based on hydrolysis and fermentation of the
raw material. The production of ethanol was, however, not studied in this project.
The main objective of the project was to identify and assess new technologies for biomass-based methanol production and to evaluate the environmental benefits of the use
of the methanol produced in transportation. New economically viable project concepts
for biomass-based methanol production by integrating synthesis gas production technology with combined heat and power production were sought for. The present profitable methanol production technology using mainly natural gas as feedstock requires a
high production capacity. Currently, the methanol production capacities of the largest
plants are more than 800 000 t/a. Capacities this high would mean long and logistically
uneconomic transportation distances for most biomass harvesting chains. The aim was
to identify and assess process concepts with decreased methanol production capacity
below 100 000 t/a. The identified process alternatives were evaluated and compared by
a techno-economic assessment.
Alternative uses of biomass-based methanol as a transportation fuel and associated
greenhouse gas emissions were evaluated. The alternatives include the use of methanol
as MTBE in fuel blends and as the main fuel for ULEV (Ultra Low Emission Vehicles)
like fuel cell vehicles. The attainable reductions in greenhouse gas emissions, compared
to conventional fuels and electric vehicle cycles, were estimated for the whole chain
from biomass harvesting to methanol use in vehicles. A rough estimate on hydrogen
production from biomass and its greenhouse impact was also made.
Simplified carbon cycles for biomass-based (biomethanol) and fossil (gasoline) transportation fuels are shown in Figure 1. As can be seen from the figure, the use of biomass-based fuels also causes CO2 emissions, but these are taken up again by new
growth in the forests, and hence the carbon cycle forms a closed loop with no net flux
into the atmosphere. According to the international agreements the CO2 emissions from
biomass combustion are not included in the national total emissions, when the biomass
originates from a sustainable source (carbon uptake is larger than the carbon released as
CO2). If the biomass use is not sustainable but causes a decline in the total carbon embodied in standing biomass (e.g. forests) this net release of carbon needs to be accounted for (IPCC 1996 Revised Guidelines 1997).
The biomass resources are used in many competing applications (pulp and paper production, wood products, heat and power production etc.) and the availability of the raw
material may be limited for all uses. Some speculative scenarios for the studied biomass-based methanol and hydrogen production concepts and for the use of the fuels in
fuel cell vehicles in light-duty vehicles in Finland and globally are presented.
13
FOREST
BIOMASS
GASOLINE
Biomethanol
recycles
carbon
No carbon
recycling back
to the source
UTILISATION
BIOMETHANOL
UTILISATION
OIL FIELD
Figure 1. The carbon cycles for a biomass-based (biomethanol) and a fossil (gasoline)
transportation fuel.
14
2. Methanol production from wood
2.1 Methanol production processes
The production of methanol from biomass, or other solid feedstocks like coal, or natural
gas involves basically several similar process units. First, raw material containing
carbon and hydrogen is converted into synthesis gas, which is a gas mixture containing
CO and H2, and then methanol is produced catalytically from the synthesis gas. The
principal method for producing synthesis gas from natural gas is steam reforming, while
synthesis gas production from biomass or coal is based on thermal gasification of solid
feedstock.
The simplified flow sheets of natural gas-based and wood-based methanol production
processes are shown in Figure 2. The wood-based methanol production process includes
the following main steps: wood drying, gasification, gas cleaning and conditioning, gas
compression, methanol synthesis and distillation. Gasification of biomass is described
in more detail in Chapter 2.2 and methanol synthesis in Chapter 2.3. The state-of-the-art
of the methanol synthesis processes was reviewed to identify the restrictions placed by
methanol synthesis on biomass gasification, gas cleaning and conditioning. Integration
of biomass gasification to methanol synthesis is discussed in Chapter 2.4.
Natural Gas
Biomass
Desulphurization
Drying
Reforming
Gasification
Methanol synthesis
Gas cleaning
Methanol distillation
CO-shift
Char, ash
Tar, ash, NH3,
other contaminants
Methanol
Acid gas removal
CO2, H2S
PSA
CO2, H2O, CO
H2
Methanol synthesis
Compression
Methanol distillation
Hydrogen
Methanol
Figure 2. Simplified flow sheets of natural gas-based and wood-based methanol
processes.
15
A simplified flow sheet of wood-based hydrogen production process is also shown in
Figure 2. The production of wood-based hydrogen is based on a synthesis gas production chain similar to wood-based methanol production. In the CO shift units the conversion of CO into H2 is maximised. In a modern hydrogen process hydrogen is separated
from the converted gas by adsorption on molecular sieves in the PSA (pressure swing
adsorption) units.
In 1997, about 86% of methanol was produced from natural gas. About 8.5% of the
production was based on heavy oil fractions, 3% on coal, and 0.5% on naphtha. In 1997
the methanol production capacity was about 31 million tonnes/a, of which 86% was
utilised. About 33% of the produced methanol was used in the gasoline and fuel sector,
while the main share of the methanol was used in the chemical industry to produce other
chemical products. (Appl 1997).
2.2 Gasification of biomass
2.2.1 Gasification reactors
In a gasifier, biomass is converted into gases (H2, CO, CO2, H2O, CH4, light hydrocarbons) and condensable tars at 800–1 200 °C. The gas also contains impurities originating from the fuel, like sulphur, nitrogen and chlorine compounds, and alkali metals. The
final product distribution in a gasification gas largely depends on gas-feedstock contact
type and process conditions.
Gasification is considered to comprise stages of drying and pyrolysis, as well as gasification and combustion reactions of residual char. The gasification reactions producing
carbon monoxide and hydrogen are highly endothermic, and hence, the heat required by
the process must be developed by partial combustion of residual char or by introducing
heat to the process, employing external heating or a heat carrier. The most conventional
method is partial combustion by using either air or oxygen. Gasification can be either an
atmospheric or pressurised process.
The main gasifier types that can, in principle, be used in biomass gasification are shown
in Figure 3. However, in practice the usability of these processes in synthesis gas
applications is limited mainly to updraft and fluidised-bed gasifiers. Examples of gas
compositions with different gasification processes are given in Table 1.
16
UPDRAFT
DOWNDRAFT
Fuel
ENTRAINED BED
FLUIDIZED BED
Fuel
Gas
Fuel
Oxygen
and steam
Gas
Drying
DRYING
Pyrolysis
PYROLYSIS
Reduction
Air
Air
Fuel
Gas
Air
Oxidation
Gas
Ash
Air
Slag
Figure 3. Main gasifier types (Energia... 1999).
Table 1. Composition of gasification gas produced employing various gasification processes and fuels (Reimert 1985, Simell et al. 1996). R is a stoichiometric value (see
Chapter 2.3.1).
Process
Method
Fuel
CO
H2
CO2
H2O
CH4
Residue
R
Fluidised bed Fluidised bed
(U-GAS)
(Lurgi CFB)
Oxygen
Coal
22.8
42.9
29.8
3.7
0.8
0.25
Oxygen
Biomass
33.5
33.4
26.6
4.9
1.7
0.11
Fluidised bed
(Battelle)
Indirect
Biomass
29
31.6
23.1
13.6
2.7
0.16
Fluidised bed
(VTT PDU
tests)
Air
Biomass
12.6
9
10.8
19.3
3.4
44.7
<0
Reformed
fluidised-bed gas
(VTT PDU tests)
Air
Biomass
18.1
17.1
7.9
15.5
0.2
41.3
0.35
Two main types of fixed-bed gasifiers are updraft and downdraft gasifiers. In the updraft gasifier the fuel is fed into the top zone of the reactor, and gasifying air or oxygen
into the lower zone. The fuel flows slowly through drying, pyrolysis, gasification and
combustion zones in the reactor. Ash is removed from the bottom. As volatiles released
in pyrolysis and drying phases are carried along with the exit gas, a high hydrocarbon
and tar content and a low temperature of gas, 300–600 ºC are characteristic of this gas.
As the operation of the updraft gasifier is based on the flow of fuel downwards and on
the flow of gases through the fuel layer, only relatively homogeneous fuel of fairly large
particle size (some cm) is suitable as fuel.
In a downdraft gasifier the fuel and the gas flow in the same direction, whereat the
hydrocarbons and tars released in pyrolysis are carried through the hot combustion and
17
gasification zone and decompose to simpler compounds. For this reason, the tar content
of gas from a well-operating downdraft gasifier is lower than that from an updraft
gasifier.
Updraft gasification has been applied in several commercial applications. The most
long-term experience has been obtained from a Lurgi gasifier developed in Germany.
This gasifier has been used for producing synthetic liquid fuels from coal by gasification at the Sasol plants in South Africa. In the 1980s, a Bioneer process was developed
in Finland for gasifying biomass and peat. There are commercial applications of atmospheric air gasification based on this process. The Bioneer gasifiers are used for generating combustion gas from peat and biofuels.
Fluidised-bed gasifiers can be divided into bubbling fluidised-bed (BFB) and circulating
fluidised-bed (CFB) gasifiers. In the bubbling fluidised-bed gasifier, the particle size of
fuel is usually less than 10 mm. The bed formed by fuel particles is fluidised with gas
flowing from below, while the product gas exits from the top zone of the reactor. Due to
good mixing, good heat and material transfer between gases and fuel particles is characteristic of this method. The temperature distribution of the reactor is fairly stable and
the temperature of the exit gas is higher than, e.g., that of the product gas from an updraft gasifier. This enables thermal cracking of tars in the reactor, and as a consequence
the tar content of gas is lower than, e.g., in updraft gasification. An abundance of partly
reacted solids exits the reactor with the gas. Part of solids are separated and recycled
into the gasifier.
In the circulating fluidised-bed gasifier, a higher velocity of fluidising gas is employed
than in the bubbling fluidised-bed gasifier. The aim is to increase the output in relation
to the cross surface, considerably higher than in the bubbling bed. Consequently, the
amount of substances exiting with gases and recycled by the circulating cyclone increases. The flow rate of gases being high, the residence time of gases in the reactor is
short. For this reason, circulating bed gasification is suitable for readily gasifying biofuels and, on the other hand, for partial gasification of coal.
Although there is an abundance of commercial experience from fluidised-bed gasification, this gasification process is still a subject of intensive development. Development is
being done, i.a., by Institute of Gas Technology (U-Gas), Kellog/Rost/Westinghouse
(KRW), Rheinische Braunkohlenwerke (HTW) and Foster Wheeler. A pilot pressurised
circulating fluidised-bed gasification plant (18 MWth) has been in operation in Värnamo, Sweden, since 1991. The plant, fuelled with wood chips and wood waste, is a
joint R&D project by Sydkraft and Foster Wheeler Energia Oy (former A. Ahlström
Oy). An atmospheric CFB gasifier (40–70 MWth) supplied by Foster Wheeler Energia
Oy is in operation in Lahden Lämpövoima Oy Kymijärvi Power Plant in Lahti, Finland.
The gasifier is fuelled with wood waste, wood chips, and waste-originated fuels. The
18
gasifier is connected to a coal boiler and the gasifier product gas is burned in the coal
boiler to substitute fossil coal by renewable fuels. The gasifier has been in operation
since 1998. Prior to the Lahti plant, Foster Wheeler Energia Oy has supplied four commercial-scale atmospheric CFB gasifiers to the pulp and paper industry in Finland,
Sweden and Portugal with capacities from 17 to 35 MWth in the mid 1980s. These plants
utilise bark and waste wood as feedstock (Palonen 1998).
Processes based on indirect gasification are of interest with regard to methanol synthesis, as they offer a possibility to produce non-nitrogenous synthesis gas without any
investment in a relatively expensive oxygen plant. In the indirect process, the gasification reactor is heated by hot bed material. The bed material is heated in a separate combustion unit operated in fluidised-bed principle by burning the mixture of residual char
and bed material separated from the product gas. An example of this gasifier type is a
Battelle gasifier, which has now reached the demonstration stage (42 MWth) in Vermont, the USA (Farris et al. 1999).
The entrained flow gasifier has been developed mainly for coal as a feedstock. The entrained flow gasifier operates at high temperature (1 300 °C), which is not necessary for
biomass with high reactivity. The feedstock must also be crushed to fine-sized particles,
which is energy and cost intensive with biomass.
2.2.2 Gas cleaning
The gasification gas contains impurities, like particulates, tar, and alkali metals, as well
as nitrogen and sulphur compounds that can be harmful in end-use applications of the
gasification gas or hamper the gas processing for the end-use. The gas cleaning requirements are process-specific. Concentration ranges of the impurities in the gasification gas produced by air-driven fluidised-bed gasification of biomass are shown in Table 2. The concentration ranges are based on VTT's experience on biomass gasification.
Table 2. Concentration ranges of the impurities in the gasification gas produced by airdriven fluidised bed gasification of biomass. The data is based on VTT's experience.
Component
Tars (benzene, naphthalene, PAH)
Nitrogen compounds (NH3, HCN)
Sulphur compounds (H2S, COS)
Chlorine compounds (HCl)
Alkali metals (Na, K)
Heavy metals (Cd, Zn, Pb, Cu, Co, V)
Particulates, dust (C, Si, Fe, Na, K, Ca, Mg, Al)
19
Concentration range
500–5 000 ppmv
300 – 10 000 ppmv
50–500 ppmv
1–200 ppmv
0.1–10 ppmv
0.1–3 ppmv
1–10 g/m3(n)
The gas clean-up requirements can be achieved by various methods. The gas cleaning
methods can be divided roughly into two methods: cold and hot gas cleaning methods.
Cold cleaning usually involves cooling and wet scrubbing of gas, e.g., with water, solvents or adsorption solutions. Solids, condensing tars and compounds soluble in the
scrubbing solution are removed from the gas. Sulphur compounds are usually removed
with the aid of special scrubbing processes. The scrubbing methods are of commercial
technology applied in the chemical industry, e.g. Selexol and Rectisol processes, and
enable the production of gas that meets very stringent purity requirements.
Hot gas cleaning usually means the filtration of gas at 300–600 °C to remove solids and
alkali metals. Other hot cleaning processes are desulphurisation with sorbents and decomposition of tars and ammonia thermally or with a catalytic process. These methods
are either commercial (hot filtration) or under development (catalytic methods).
Reforming of gas with a nickel cell catalyst at about 900 °C is one of the most developed catalytic methods today. With this method (Simell et al. 1996), developed in collaboration by VTT and BASF AG, a nearly complete conversion of hydrocarbons into
gases (CO, H2) and about 80% ammonia conversion have been achieved in pilot-scale
test equipment. The main components of gasification gas also react under the conditions
applied and their contents at the outlet of the reactor have been close to the thermodynamic equilibrium contents of gas. The nickel cell also seems to endure the hydrogen
sulphide content of gas (50–100 ppm) without deactivation under the conditions applied, and the cell has been found to endure real gasification conditions in an experiment of 500 operation hours. However, considerable longer-term testing (thousands of
hours) is required to verify the usability of the technology.
2.3 Methanol synthesis
2.3.1 Reactions
Methanol formation in the synthesis gas can be formulated as the following reactions of
hydrogen with carbon oxides (Appl 1997):
CO + 2H2 ↔ CH3OH
∆H0298 = -90.8 kJ/mol
(1)
CO2 + 3H2 ↔ CH3OH
∆H0298 = -49.6 kJ/mol
(2)
These two reactions are linked by the reverse shift conversion reaction:
CO2 + H2 ↔ CO + H2O
∆H0298 = 41.2 kJ/mol
20
(3)
Both reactions 1 and 2 are exothermic and result in a decrease in volume. Methanol
formation is thus favoured by increasing pressure and decreasing temperature, the
maximum achievable conversion being limited by the chemical equilibrium.
According to the stoichiometry as given in equations 1–3, the ideal ratio for the synthesis gas should be (Appl 1997):
R = (H2 – CO2) / (CO + CO2) = 2
(4)
where H2, CO and CO2 represent the respective concentrations in the synthesis gas.
2.3.2 Reactors
A specific feature of methanol synthesis is that only a small proportion of synthesis gas
is converted into methanol per pass in the reactor. To achieve as high a total conversion
of basic materials as possible, synthesis gas is recycled into the reactor. The reaction
products, methanol and water, are separated from the outlet gas of the reactor, and fresh
gas is then added to it. The gas is then recompressed to the synthesis pressure and led
into the reactor. The temperature of the reactor is carefully controlled to maintain the
best conditions for the chemical equilibrium. In current processes (low-pressure methanol synthesis) the operating temperature is typically 200–300 °C and the pressure 45–
100 bar depending on the catalyst. The principle of the basic methanol synthesis process
is shown in Figure 4.
Figure 4. Methanol synthesis, principle of the basic process (Appl 1997).
21
There are several suppliers of the methanol synthesis reactors, for example, ICI, Lurgi,
Linde, and Mitsubishi Gas Chemical. Different methanol processes deviate from each
other primarily in the construction of the reactor. There are differences in the management of the removal of heat formed in exothermic reactions in the reactors. On this basis, the reactors can be divided into two main types: quench-cooled and indirectly
cooled reactors. In a quench-cooled reactor, the reactor is prevented from overheating
by leading cooled gas into the catalyst bed. The structure of indirect reactors is similar
to that of a tube heat exchanger, in which the catalyst can be placed either on the side of
the tube or the mantle. The reaction heat is recovered in the cooling water flowing either
on the side of the mantle or the tube. Examples of the both reactor types are shown in
Figures 5 and 6. (Appl 1997).
Figure 5. ICI's quench-cooled methanol synthesis converter (Appl 1997).
22
Lurgi's tubular reactor
Linde isothermal reactor
Figure 6. Indirectly cooled reactors (Appl 1997).
Several research groups have investigated concepts, in which methanol is continuously
removed from the reaction zone by a solid or liquid absorption medium (Appl 1997).
The aim with these concepts is to avoid the typical disadvantages of the current
methanol processes, e.g., the low conversion per pass and the consequent need for high
recycle ratios. Among these approaches, the liquid-phase process developed by Air
Products and Chemicals seems to be the most promising one. Currently the process is at
a demonstration stage (Heydron et al. 1998).
In the Air Products process (Appl 1997), fine particles of catalyst are suspended in an
inert mineral oil and the synthesis gas passes through the catalyst-oil slurry in fine
bubbles. A simplified flow diagram of the process is shown in Figure 7. The process has
been reported to have a higher methanol conversion per pass than the current
conventional methanol processes, although the actual conversions have not been
published. The process is also said to be particularly well suited to substoichiometric
synthesis gases, like the synthesis gases produced by gasification. In combination with
some gasification processes, it might even be possible to run the process as a oncethrough process. In these process concepts, the purge gas of the methanol synthesis
would be used for energy production, e.g. in a combined cycle.
23
Figure 7. Methanol process of Air Products and Chemicals Inc. (Appl 1997).
The commercial catalysts for methanol synthesis are manufactured, e.g., by ICI Katalco,
Süd-Chemie / United Catalysts, Topsøe, BASF, and Mitsubishi Gas Chemical. The
catalysts currently used in methanol synthesis reactors are composed of copper oxide
and zinc oxide stabilised with alumina, and only proportions of these components vary
by the manufacturer (Appl 1997). These copper-based catalysts are particularly sensitive to sulphur and chlorine impurities.
2.4 Integration of gasification to methanol synthesis
The gasification product gas cannot be used as such in methanol synthesis. The gasification gas always contains impurities, like dust, tar, as well as nitrogen and sulphur
compounds that must be removed from the gas prior to further treatment. The gas composition must be adjusted to meet the requirements of methanol synthesis chemistry.
Requirements concerning the purity and composition of gas are the same for all present
methanol processes employing copper-based catalysts. In general, the synthesis gas
should meet the requirements listed below (Supp 1990). In addition, the gas should
contain neither water nor residues of solvents possibly used for gas scrubbing.
−
The stoichiometric ratio R should be 2–2.1.
−
At the above stoichiometric rate, the CO content of gas should be as high as possible
and the CO2 content as small as possible, but not less than 2.5 wt%.
−
The content of inert gases should be as small as possible (to reduce production costs,
the inert gases do not hamper the process).
24
−
The content of sulphur compounds should be less than 0.1 ppm.
−
The content of other compounds, Cl, HCN, NH3 and unsaturated hydrocarbons
should not exceed 0.1–3 ppm.
Efficient gas cleaning and conditioning is needed to meet these requirements. Gasification should be either oxygen-driven or indirectly heated in order to avoid the costly
ballast of inert gases (nitrogen from air). After gasification, the gas can be reformed
with a catalyst to achieve the maximum conversion of hydrocarbons into gases (CO,
H2). After the reformation unit, water scrubbing is needed for removing the remaining
condensable tars, solids, and ammonia from the gas. In addition, the composition of gas
must be converted by CO conversion (shift) units to adjust the stoichiometric ratio of
gas in the range required by methanol synthesis. Sulphur compounds and carbon dioxide must be removed with the aid of special scrubbing processes. An example of a possible process concept for wood-based methanol production is shown in Figure 8.
Figure 8. Simplified scheme of a possible process concept for wood-based methanol
production (Beenackers & van Swaaij 1984).
2.5 Performance and costs of wood-based methanol processes
Many techno-economic assessments have been carried out and published on methanol
production concepts based on biomass gasification. Several development projects have
also been carried out in the field, but none of the projects have led up to a commercialscale production. In principle, all the process units of the wood-based methanol process
can be found based on commercial technology. A comparable process was demonstrated
in the 1980s in Oulu, Finland, when 80 000 tons/a of ammonia was produced based on
pressurised gasification of peat in the Kemira Oyj plants. Sawdust was also used in test
runs. The plant was shut down at the beginning of the 1990s due to the declined world
market price of ammonia.
The presented mass yields of methanol from wood usually range from about 45 to 55
wt% of dry wood. In a study funded by DOE (1990), the methanol yield of 43.5 wt%
25
based on dry wood was presented for the conventional process and 50.8 wt% for the
future process (employing the pressurised gasification, tar reformer and liquid-phase
methanol synthesis). Elam et al. (1994) have estimated that employing the best possible
technology in the wood-based methanol process the maximum methanol yield would be
55 wt% of dry wood and that the current processes would allow methanol yields around
45 wt% of dry wood. Williams et al. (1995) have presented methanol yields of 48–
58 wt% of dry wood depending on the gasification technology applied.
Elam et al. (1994) have compared the investment and production costs of wood-based
methanol and ethanol. In the methanol process concept studied the excess heat of the
methanol production was used for district heat production in order to improve the overall efficiency of the wood-based methanol production process. The production of synthesis gas was based on pressurised oxygen-driven gasification. The total efficiency of
the methanol process was 82% (LHV basis), and the methanol production efficiency
was 55% (LHV basis). The production costs of 14 EUR/GJ were presented for the plant
capacity of 250 000 tons dry wood/year (141 MWth, moist wood, LHV basis).
Williams et al. (1995) have compared the production costs of wood-based methanol and
hydrogen with the production costs of natural gas and coal based methanol and hydrogen. The production costs of 11.2–14.1 USD/GJ and 8.7–11.2 USD/GJ were presented
for wood-based methanol and hydrogen production, respectively, depending on the gasification technology applied. The plant capacity was 1 650 tons dry wood/day. The
thermal efficiency of processes was 53.9–61.0% for wood-based methanol production
and 56.4–64.5% for hydrogen production. Purge gases were assumed to be used for
electricity production with efficiencies achievable in a gas turbine/steam turbine combined cycle.
In the study funded by DOE (DOE 1990), the methanol production costs of the conventional technology were compared with the costs of the future technology. The conventional process was based on the atmospheric gasification of the wood and the conventional methanol synthesis, and the future process on the pressurised gasifier followed by
the methane reformer and the liquid-phase methanol synthesis. The production costs
presented were 18.8 EUR/GJ for the conventional process and 13.5 EUR/GJ for the
future one. The capacity of the plant was 603 000 tons dry wood/year.
Faaij et al. (2000) have presented preliminary results of their study on the production of
methanol and hydrogen from biomass via advanced conversion concepts. The work
focuses on identifying conversion concepts that may lead to higher overall efficiencies
and lower costs. Improved performance is sought by applying technologies under
development, a combined fuel and power production and the economics of the scale.
Preliminary results indicate that overall energy efficiencies remain in 50–60% (based on
26
fuel input, HHV basis). The preliminary production costs of 8.5–12 USD/GJ for
methanol and 7.5–9 USD/GJ for hydrogen were presented for the plant with the feed
capacity of 400 MWth (LHV basis).
2.6 Performance of wood-based methanol process integrated
to CHP production
Based on the state-of-the-art review of methanol synthesis and VTT's experience on
biomass gasification, the process concept shown in Figure 9 was built for the study.
Cost reductions were sought by integrating the methanol production to an existing combined heat and power (CHP) production plant in the forest industry. A similar type of a
process concept has been suggested for wood-based ethanol production in Sweden
(NUTEK 1995). In the Swedish study the possibilities to decrease the production costs
of wood-based ethanol by integrating the ethanol production with other existing industrial plants (a pulp mill, a combined heat and power plant, and a combinate of peat drying and a saw mill) were identified.
The selected methanol process is based on pressurised oxygen-driven gasification followed by the tar reformer and the conventional methanol synthesis. The options of the
gasification technology were the oxygen-driven and the indirectly heated gasifier. The
oxygen-driven gasification was selected based on the following arguments, similar
Boiler
Fuel gases
Bark, other wood fuels
Nitrogen
Purge
gas
Oxygen
Air
Make-up
water
Dryer
CO2, H2O, H2S
Gasifier
Steam
Steam
Wood
Tar
reformer
Oxygen
Steam
Waste water
Water
scrubber
Methanol
Steam
CO
Shift
Acid gas Methanol
removal synthesis
Distillation
Ash, char
Figure 9. Methanol production combined to CHP production at a pulp and paper mill.
Steam production and utilisation is combined to a steam cycle of the pulp mill.
27
arguments having also been presented by Elam et al. (1994). When applying the oxygen-driven gasification the costly investment for the oxygen-production is needed, but
on the other hand, with the indirectly-heated gasification higher investment costs are
needed for the gasification section, since it is formed of two reactors, namely the gasifier reactor and the combustor. The oxygen-driven gasification is easier to pressurise
than the indirectly heated one. The product gas of indirect-heated gasification contains
more light hydrocarbons and tar than the product gas of oxygen-driven gasification due
to a larger consumption of steam as gasification medium and a lower gasification temperature. The larger amount of tars in the product gas increases the gas cleaning costs. It
was also considered that the gas composition more suitable for the methanol synthesis
produced by indirectly heated gasification is compensated by the higher total efficiency
of the gasification and gas cleaning section typical of oxygen-driven gasification.
The gasification product gas is led to a reformer utilising the nickel cell catalyst to
reform the light hydrocarbons and tar to CO and H2. The reformer is directly heated by
oxygen. After the reformation unit the remaining condensable tars, solids, and ammonia
are removed from the gas by water scrubbing. Before the water scrubber the gas is
cooled down. After water scrubbing the gas is converted in the CO shift units, and acid
gases are removed from the gas by a commercial scrubbing process.
In the studied process the methanol production is maximised. The conventional methanol synthesis technology was selected for the process, since the liquid-phase methanol
synthesis technology under development was considered to be more suitable for the
process concepts based on the once-through methanol synthesis.
The steam cycle of the methanol plant is connected to the steam cycle of the CHP plant
of the pulp mill. In the methanol plant, steam is used in the gasification, CO shift conversion, and distillation. Steam is raised in the cooling of gasification gas before the
water scrubber and in the waste heat removal of methanol synthesis.
Two methanol production concepts were selected for evaluation: methanol production
integrated to an existing pulp mill in Finland and in the Far East. In the Far East case the
cost reductions were sought by the economics of the scale and lower price of the raw
material. The fast growth of wood would allow higher capacities for methanol production in the Far East than in Europe. No specific country for the Far East case was defined, but Indonesia is a typical example. The plant capacities were set at 100 MWth
(moist wood, LHV) as a fuel input to the gasifier in the Finnish case and 500 MWth in
the Far East case. The capacities were selected based on the availability of the raw material at a moderate price (2.1 EUR/GJ in Finland and 1.6 EUR/GJ in Far East). In the
Finnish case the raw material was forest residues (pine) and in the Far East case short
rotation coppices (eucalyptus).
28
The model of the methanol process was built for mass and energy balance calculations
employing Aspen Plus programme as a tool. The mass and energy balances of the
methanol processes are based on the experience of VTT Energy, the public literature
(especially DOE 1990, Katofsky 1993, Elam et al. 1994, Williams et al. 1995) and on
the discussions with equipment suppliers, especially Linde AG.
The estimated performances of the methanol plants are presented in Table 3. The
methanol production would be 83 400 t/a in the Finnish case and 439 400 t/a in the Far
East case. The mass yield of methanol was estimated at 50% of dry wood and the
energy yield at 57.7% of the raw material (lower heating values) for forest residues
(pine) as the feedstock and 49% and 60.8%, respectively, for eucalyptus. The total
efficiency of the methanol production process was estimated at 66.7% (LHV) for forest
residues and 68.7% for eucalyptus, taking into account all the energy needed and all the
products (methanol, steam, combustible side-products).
Table 3. Performances of the methanol plants.
Case
Wood consumption
t/a (moisture 50%)
MW (LHV)
Steam consumption, MW
Power consumption, MW
Methanol production
t/a
MW
Steam generation, MW
Other side-products, MW
Methanol yield, wt-% of dry wood
Methanol yield, % (LHV/LHV feedstock)
Total efficiency (LHV), %
Finland
Far East
333 800
100.0
25.5
11.0
1 794 000
500.0
135.5
60.0
83 440
57.7
33.3
9.9
50.0
57.7
66.7
439 400
303.9
177.7
51.5
49.0
60.8
68.7
Further improvements in the total efficiency could be achieved by process optimisation
(optimised gasification temperature, minimised oxygen consumption, high carbon conversion in gasification, small hydrocarbon content in the gasification gas, optimised
methanol synthesis).
Utilising lower-grade waste heat for the production of district heat in the Finnish case or
hot water for the forest industry process would increase the overall efficiency of the
methanol plant, e.g. Elam et al. (1994) presented the total efficiency of 82% for the
methanol plant integrated to district heat production. As in Finland the district heat load
close to the forest industry is often already covered, the possibility for district heat production was not considered. No detailed integration of methanol production to the water
29
system of the pulp mill was carried out. Typically, the pulp and paper industry has
overproduction of lower grade heat.
Both in the Finnish case and in the Far East case the methanol process was combined to
a non-integrated kraft pulp mill. The plants have a conventional recovery boiler and a
bark/wood boiler for the energy production. The simplified flowsheet of the power plant
at a pulp mill is shown in Figure 10. The feedstocks of the pulp production are pine in
the Finnish case and eucalyptus in the Far East case. The annual production of chemical
pulp is 600 000 adt/a (air-dry tons/year). Currently the largest capacity among the Finnish pulp mills is 620 000 adt/a (Stora-Enso, the Enocell mill).
480 °C, 84 bar
12 bar
4.5 bar
50 °C
Bark
Make -up wate r
110 °C
Black
liquor
Figure 10. Simplified flowsheet of the power plant at a pulp mill.
The performances of the energy production in the pulp mills were determined using an
Aspen PlusTM model based on data provided by Jaakko Pöyry Consulting Oy (Jaakko...
1993) and on the publication by Komulainen et al. (1994). The pulp production from
eucalyptus is also based on the publication by Gullichsen (1968). The main operating
data for the energy production of the pulp mills are presented in Table 4. The main operating data of the integrated methanol and pulp plants are presented in Table 5.
The performance of a comparable hydrogen plant was roughly estimated for the Finnish
case. The estimation is based mainly on the publication by Williams et al. (1995). The
estimated performance of the hydrogen plant and the integrated hydrogen plant and the
pulp mill are presented in Tables 6 and 7. The results should be considered as indicative. The hydrogen production was estimated to have a higher fuel yield than the methanol production, 70% and 58% (LHV basis), respectively. Due to the higher power consumption in the hydrogen production, the difference in the total efficiency was smaller,
70% and 67% (LHV basis), respectively.
30
Table 4. The main operating data of the kraft pulp mills. The production of chemical
pulp is 600 000 adt/a in both cases.
Case
Raw material
Wood consumption, t ds/a
Steam generation, MW
Black liquor
Bark
Steam consumption in pulp mill, MW
Generated power, MW
Power consumption, MW
Power for sale, MW
Finland
Pine
851 000
431.7
370.5
61.2
224.9
100.3
39.6
60.7
Far East
Eucalyptus
769 000
399.2
343.1
56.1
224.9
89.8
39.6
50.2
Table 5. The main operating data of the integrated methanol and pulp plants.
Case
Raw material in pulp production
Raw material in methanol production
Wood consumption in pulp mill, t ds/a
Wood consumption in methanol plant, t ds/a
Methanol production, t/a
Methanol production, MW
Pulp production, adt/a
Steam generation, MW
Black liquor
Bark + side-products of methanol
production
Steam generation in methanol production
Steam consumption in pulp mill, MW
Steam consumption in methanol plant, MW
Generated power, MW
Power consumption in pulp mill, MW
Power consumption in methanol plant, MW
Power for sale, MW
Finland
Pine
forest residues (pine)
851 000
167 000
83 400
57.7
600 000
473.4
370.5
69.6
33.3
224.9
25.5
109.7
39.6
11.0
59.1
Table 6. The indicative performance of the hydrogen plant.
Case
Wood consumption
t/a (moisture 50%)
MW (LHV)
Steam consumption, MW
Power consumption, MW
Hydrogen production
t/a
MW
Steam generation, MW
Other side-products, MW
Hydrogen yield, wt% of dry wood
Hydrogen yield, % (LHV/LHV feedstock)
Total efficiency (LHV), %
Finland
333 800
100
16
18
16 700
70
21
14
10
70
70
31
Far East
Eucalyptus
Eucalyptus
769 000
897 000
439 400
303.9
600 000
620.8
343.1
100.0
177.7
224.9
135.5
131.3
39.6
60.0
31.7
Table 7. The indicative main operating data of the integrated hydrogen and pulp plant.
Case
Raw material in pulp production
Raw material in hydrogen production
Wood consumption in pulp mill, t ds/a
Wood consumption in hydrogen plant, t ds/a
Hydrogen production, t/a
Hydrogen production, MW
Pulp production, adt/a
Steam generation, MW
Black liquor
Bark + side-products of hydrogen production
Steam generation in hydrogen production
Steam consumption in pulp mill, MW
Steam consumption in hydrogen plant, MW
Generated power, MW
Power consumption in pulp mill, MW
Power consumption in methanol plant, MW
Power for sale, MW
Finland
Pine
Forest residues (pine)
851 000
167 000
16 700
70
600 000
459
371
73
21
225
16
107
40
18
50
2.7 Costs of wood-based methanol process integrated
to CHP production
The methanol production costs were estimated for the wood-based methanol process
integrated to an existing power plant of a non-integrated pulp mill. No detailed optimisation of integrating the methanol plant to a specified existing pulp mill was carried out.
The following main assumptions in the integration and cost estimation were used:
− the following existing equipment of the pulp mill can be utilised in the methanol
production: raw material reception, power plant, waste water treatment, utility systems, and treatment of sulphurous gases
− the utilities are bought from the pulp mill
− the combustible side-products of methanol production are sold to the power plant
− the steam produced in the methanol plant is sold to the pulp mill, the price of steam
depending on the steam pressure.
In the Finnish case the studied capacity of methanol production fits well in a context of
a modern pulp mill, but in the Far East case the higher methanol production capacity
would probably yield some investments in increasing capacity. For example, in the
Finnish case the integration of methanol production to the pulp mill increases the
capacity of the bark boiler only from 61.2 MW to 69.6 MW, while in the Far East case
the capacity increases from 56.1 MW to 100 MW. Therefore, the estimated costs of the
Far East case should be considered as the minimum.
32
The production costs comprise fixed and variable production costs and capital charges.
Annual capital charges were estimated from the capital investments by the annuity
method. The estimated investment costs are based on public information, mainly on the
publications by Elam et al. (1994) and Williams et al. (1995). The investment costs of
different origin were unified and adjusted to the price level of spring 1999 using Chemical Engineer Index. By-product credits were taken into account by subtracting the income received by selling the by-products from the annual production costs. The price of
the feedstock was used as the value of combustible by-products. The main parameters of
the cost estimation are presented in Table 8. The cost estimation is based on the plant
capacities and performances presented in Chapter 2.6.
Table 8. Main parameters in the cost estimation.
Time of the investment
Place of the investment
Annual operating time
Plant life
Interest rate
Feedstock price, forest residues/Finland
Feedstock price, eucalyptus/Far East
Electricity price
Steam price
Spring 1999
A pulp mill, Finland/Far East
8 000 h/a
20 a
10%
7.6 EUR/MWh
5.9 EUR/MWh
25.2 EUR/MWh
11.8–16.8 EUR/MWh (depending on the
pressure level)
The estimated investment costs of the methanol production plants are presented in Table
9. The fixed capital investment was estimated at 87 MEUR for the methanol plant in
Finland and 238 MEUR for the plant in the Far East. The total capital requirement was
estimated to be 112 MEUR and 305 MEUR, respectively. The cost reductions achieved
by utilising the existing equipment of the pulp mill were estimated to be about 20%. It
should borne in mind that the accuracy of this kind of cost estimate is ±30%.
Table 9. Investment costs of the wood-based methanol plant.
Investment cost, million Euro
Fixed capital investment
Contingencies
Fixed capital investment
Start-up
Working capital
Interest during construction
Total capital requirement
Capital to be depreciated
Finland
79.4
7.9
87.3
8.7
4.4
11.3
111.7
107.4
33
Far East
216.6
21.7
238.2
23.8
11.9
31.0
305.0
293.0
The production costs in the Finnish case were estimated at around 16 EUR/GJ methanol, i.e. more than threefold compared to the current prices of methanol. In the Far East
case the methanol production costs were lower, approximately 10 EUR/GJ methanol,
which is about twice the current prices of methanol. Since the produced methanol was
considered to be used in Europe the costs of sea transportation (20 USD/m3, IEA/AFIS
1998) were added to the production costs in the Far East case. The combined production
and transportation costs are then about 11 EUR/GJ. The methanol production costs are
presented in Figure 11 and in further detail in Table 10.
The production costs of comparable hydrogen production for the Finnish case were estimated roughly. The fixed capital investment was estimated at 68 MEUR and the total
capital requirement at 87 MEUR, i.e. about 20% less than the comparable costs of
methanol production due to the simpler process. The production costs were estimated at
12.5 EUR/GJ, i.e. about 20% less than the comparable costs of methanol production.
Employing the district heat production for utilising the low-grade waste heat and optimising the integration of the methanol plant to the pulp mill would increase the total
efficiency. Further improvements in the total efficiency of the methanol plant and consequent reductions in the production costs could be achieved by process optimisation
(optimised gasification temperature, minimised oxygen consumption, high carbon conversion in gasification, small hydrocarbon content in the gasification gas, optimised
methanol synthesis).
WOOD-BASED METHANOL
Production costs
EUR/GJ
25
Investment year 1999
Capital costs with annuity method
Rate of interest 10%, service life 20 a
Operating time 8000 h/a
Feedstock prices
Finland 2.1 EUR/GJ
Far East 1.6 EUR/GJ
20
15
10
Methanol
market price
5
0
MeOH
Finland
Feed 100 MW
MeOH
Far East
Feed 500 MW
Utilisation in Europe
Hydrogen
Finland
Feed 100 MW
Indicative
Figure 11. Methanol production costs.
34
Table 10. Production costs of the wood-based methanol.
Costs, EUR/GJ
Fixed operating cost
Operating labour
Maintenance labour
Overheads
Maintenance materials
Taxes, insurance
Others
Total
Variable operating cost
Feedstock
Electricity
Chemicals
Steam
Water, waste water
Total
By-product credit
Capital charges
Production cost
Sea transportation
Production and transportation costs
Finland
Far East
0.5
0.5
0.3
1.6
1.1
0.5
4.5
0.2
0.3
0.1
0.8
0.6
0.3
2.3
3.6
1.3
0.3
1.6
0.0
6.9
2.8
7.9
16.4
2.7
1.4
0.3
1.6
0.0
6.0
2.8
4.1
9.6
1.2
10.8
16.4
35
3. Greenhouse gas emissions for selected fuel
production and use chains
Many alternative fuels and vehicle technologies are in use today, and in the future more
choices will be available as new technologies evolve. In this study the greenhouse gas
emissions of biomass-based methanol use as a transportation fuel were compared with
those of a selected set of other automotive fuels and engine technologies. For all cases
the greenhouse gas emissions for full fuel cycles are presented. The following cases of
use were considered:
1.
a) Reformulated gasoline (RFG) in light duty vehicles (95E, 2% oxygen,
10% MTBE (methanol from natural gas))
b) Diesel in light-duty vehicles
2.
Reformulated gasoline in light-duty vehicles, same as the reference case above, but
methanol for MTBE production is produced from biomass
3.
Methanol (both from biomass and natural gas) in fuel cell vehicles
4.
Gasoline and methanol (both from biomass and natural gas) in ICE-hybrid vehicles
5.
Electrical vehicles with
a) electricity produced from biomass
b) electricity from average production (Europe).
The greenhouse gas emissions for hydrogen production from biomass and its use in fuel
cell vehicles were also estimated, but the emission estimates are based on rougher and
more uncertain data.
The fuel chain greenhouse gas emissions for methanol production from wood-based
biomass are presented for the cases described in the previous chapter (Finland (pine)
and the Far East (eucalyptus)). In the Finnish case the production and end use is assumed to take place in Finland. In the Far East case the methanol production is assumed
to take place in the Far East and the use of the fuel take place in Europe (the methanol is
assumed to be shipped to Europe). The existing methanol production from natural gas
and the gasoline and diesel production from crude oil are considered as reference cases.
Greenhouse gas emissions from the production of the fuels (methanol from natural gas
and biomass, gasoline and diesel from crude oil, hydrogen from biomass) are presented
in Chapter 3.1. The emissions of local fuel distribution are presented in Chapter 3.2 and
emissions from fuel use in different kinds of vehicles in Chapter 3.3. Finally, in Chapter
3.4, the total fuel chain greenhouse gas emissions of the different cases are put together
and compared.
36
In the calculations the biomass is assumed to originate from a sustainable source and
therefore the associated CO2 emissions are not taken into account. The availability of
sustainably grown biomass is addressed in Chapter 4.
3.1 Emissions from fuel production
3.1.1 Methanol production from natural gas
Two alternative production chains of fossil methanol fuel (i.e., methanol derived from
natural gas) are presented below in a simplistic schematic diagram (Figure 12).
Natural gas (NG) production (oil well)
A
B
Steam reforming and
methanol synthesis
Shipping/transfer of NG
Steam reforming and
methanol synthesis
Shipping of methanol
Delivery
Utilisation as automotive fuel
(or as MTBE)
Figure 12. Two alternative production chains of fossil methanol fuel (derived from
natural gas).
Natural gas is often a by-product of crude oil drilling, and the emission factors for crude
oil production are used here also for natural gas production. IEA/AFIS (1996) reports
emission factors of 0.85 kg CO2/GJ and 0.79 g CH4/GJ for North Sea production. Calculated as CO2 equivalents (global warming potential (GWP) factors for CO2 is 1 and
for CH4 21 for the time period of 100 years) this gives 0.87 kg CO2(eq)/GJ.
Methanol is usually produced from natural gas by steam reforming. The synthesis processes can take place either in connection with natural gas production (at the production
field) or near the end-use destination (long-distance transport as natural gas). The shipping of LNG (liquefied natural gas) is more costly than that of methanol, and hence, the
production of methanol often takes place at the production field. Transferring the natural gas along pipelines also enables the methanol production near the end-use destination (alternative B, Figure 12).
37
During the steam reforming and methanol synthesis processes some leakage of methane
can occur, but there is no data on them available. These emissions are, however, expected to be small. Carbon dioxide emissions caused by the energy use of the conversion of natural gas to synthesis gas and methanol are of the order of 8 kg CO2/GJ
CH3OH (Ecotraffic 1992).
In methanol shipping (alternative A, Figure 12) the transported methanol itself could be
used as transportation fuel. The option to use methanol in shipping is, however, not considered in this report.
Natural gas (alternative B, Figure 12) is transferred either in pipelines or shipped in liquefied form (LNG). Methane leakages during pipeline transfer are country- and casespecific, depending on the condition and maintenance of pipelines. In Finland, the GHG
emissions of pipeline transfer are estimated at approximately 0.1 kg CO2(eq)/GJ of
natural gas transferred (Energy-Ekono 1997). Natural gas burned as fuel in shipping of
LNG produces 2.75 kg CO2/kg CH4, about 58.5 kg CO2/GJ of natural gas (IEA/AFIS
1996).
The summary of the greenhouse gas (GHG) emissions for the different natural gas-tomethanol production chains, assuming a conversion efficiency of 82% for the synthesis
process, is presented in Table 11.
Table 11. Greenhouse gas emissions of the alternative production chains of fossil
methanol derived from natural gas. (Initial data: IEA/AFIS 1996).
Process alternative A
kg CO2(eq)/GJ MeOH
natural gas production
1.1
steam reforming and
8
methanol synthesis *
shipping of methanol
1.0
TOTAL
Process alternative B1
natural gas production
shipping of natural gas
as LNG *
steam reforming and
methanol synthesis *
10.1
Process alternative B2
1.1 natural gas production
1.1 pipeline transfer of
natural gas **
8
steam reforming and
methanol synthesis *
10.2
1.1
0.1
8
9.2
* kg CO2/GJ ** in Finland (Energy-Ekono, 1997)
Energy-Ekono (1997) has estimated the greenhouse gas emissions for methanol production in a case, where the fossil methanol would be produced in Finland using natural gas
from Russia. These estimates are roughly eight times higher than those given in Table
11 (alternative B2: natural gas production and pipeline transfer of natural gas). The difference can probably be explained by the fact, that the Russian natural gas net is not in
as good a condition as the Finnish net and the leakages are much larger. The corresponding fuel chain greenhouse gas emissions are presented in Table 12. In estimating
38
the total fuel chain greenhouse gas emissions in this study, the values of alternative B2
in Table 11 are used.
Table 12. Greenhouse gas emissions for the production fossil methanol assuming production in Finland from natural gas from Russia (Initial data: Energy-Ekono 1997;
IEA/AFIS 1996).
Process step
Natural gas production, refining and transportation in Russia
Steam reforming and methanol synthesis in Finland *
Methanol from NG production chain, total
kg CO2(eq)/GJfuel
8.1
8
16.1
* kg CO2/GJ
3.1.2 Methanol production from wood-based biomass
3.1.2.1 The production chains
Besides from natural gas, methanol can be produced from almost any other carboncontaining raw material, like biomass. High production costs have been the main limiting factor in introducing methanol production from biomass. According to international
agreements, the carbon dioxide emissions from biomass burning are considered as zero,
when the biomass is grown in a sustainable manner (i.e. annual use is less than annual
growth) (IPCC 1996 Revised Guidelines 1997). Hence, the CO2 emissions from combustion of methanol made from biomass need neither be taken into account. The emissions from fossil fuel use in the biomethanol production chain (harvesting, transportation of raw material etc.) must, however, be considered. The estimation of these emissions is described below for the Finnish and the Far East cases.
1) The Finnish case
The process concept (the Finnish case) considered here is as follows: the methanol production plant (including biomass gasification, gas cleaning and methanol synthesis processes) is combined to an energy production system at an existing kraft pulp mill, which
consists of recovery boiler, bark boiler, steam cycle, and steam turbine. The kraft pulp
mill provides an excess supply of energy. All the electricity and steam required in the
methanol process come from the energy production at the pulp mill. In addition, all
combustible by-products from methanol production are carried to the bark boiler, reducing the amount of supplementary fuel (forest residue) possibly needed for the increased demand of electricity and steam production caused by the methanol production.
The steam produced in the methanol production plant is also introduced to the steam
cycle of the pulp mill.
39
In the Finnish case, the raw material is assumed to be forest residues and no supplementary fossil fuels are needed for the methanol production. The combustible byproducts and steam from the methanol production process cover the additional demand
of energy (electricity + steam). The net power production of the integrated plant is,
however, 2–3 per cent less than that of the non-integrated power plant.
All the CO2 emissions of the integrated plant originate from biomass (sustainable origin,
need not to be considered) and the emissions of the other greenhouse gases, CH4 and
N2O, are estimated to be negligible. For the production process (gasification and methanol synthesis) no greenhouse gas emissions are therefore taken into account in the calculations.
A rough schematic production chain of methanol derived from forest residues (chips) is
shown in Figure 13.
The production chain of wood chips from forest
residues (collecting, terrain transport, roadside
chipping, long-distance transport)
flue gas
Pre-treatment (drying, sizing)
steam
steam
Gasification process (syngas)
electricity
Methanol synthesis
purge gas,
distillation residue
Delivery
Utilisation as automotive
fuel (or as MTBE)
Figure 13. The production chain of methanol fuel derived from wood-based biomass.
The arrows describe flows from and to the bark boiler.
2) The Far East case
In the Far East case the short rotation coppices (eucalyptus) are used for methanol production. The fast growth of wood would allow for higher capacities (and thus, lower
production costs) for methanol production in the Far East than in Europe. The wood
consumption of the methanol production process also exceeds that needed for the nonintegrated pulp mill, due to the large production capacity. In the Far East the methanol
40
production plant is five times bigger than in the Finnish case (see Tables 2–4). Otherwise the production concept (integrated to kraft pulp mill) is similar to the Finnish case,
and zero greenhouse gas emissions from the production are assumed. The total net energy (power + steam) produced is, as in the Finnish case, larger than that for the nonintegrated plant. The net electricity production decreases, however, much more, approximately by 30–40 per cent.
The methanol produced in the Far East is transported to and used in Europe. Long-range
sea transportation also produces GHG emissions, which must be added to the fuel chain
emissions.
3.1.2.2 Emissions from the fuel supply chains
1) The Finnish case
The production of wood chips from forest residues comprises a number of steps (Figure
14). After the trees have been cut and delimbed, the remaining logging residue must be
collected and chipped. In addition, some forest transport is needed in order to haul forest
residues to a roadside for chipping. The wood chips are then transported further to the
end-use location. The forest tractors and chippers that produce the wood chips are fuelled with petroleum fuels (diesel oil) and hence produce carbon dioxide and other
greenhouse gas emissions.
Figure 14. Harvesting chain of logging residue based on roadside chipping (Alakangas
et al. 1999).
41
Because stemwood is produced anyway, only greenhouse gas emissions from forest
residue collecting, forest transport and chipping are considered. Pingoud et al. (1999)
give an energy consumption value of 1.08 dm3 diesel/m3 chips produced. Use of this
value would give CO2 emissions of 3 160 t for the wood chip production in the Finnish
case [334 000 t (800 GWh/a, see chapter 2) wood chips for methanol production, average moisture of 50% and average density of 300 kg/m3 employed in the calculation].
Long-distance transportation of wood chips from a roadside chipping site to a methanol
production plant is assumed to be based on diesel fuel use. Using the value of
51 dm3 diesel/100 km (Pingoud et al. 1999), the CO2 emissions due to transport of
wood chips amount to 1 340 g CO2/km. The total transportation mileage assuming a
transportation distance of 40 km (one way) and an average value of 100 m3/truck would
be
2 x 40 km/truck x 11 139 trucks/a = 891 120 km/a.
The return trip of the empty truck is also considered. Thus, the CO2 emissions due to
transports of wood chips would amount to 1 194 t CO2/a. The maximum transportation
distance (less than 100 km) is determined by economical feasibility. In the case of oneway distance of 100 km, the corresponding CO2 emissions would be 2 985 t CO2/a.
The total CO2 emissions from the production and transports of wood chips (distance
40 km) would then be 4 353 t CO2/a (or max. 6 145 t CO2/a for distance 100 km). The
specific CO2 emissions calculated from these total emissions are presented in Table 13.
Table 13. The specific CO2 emissions from the production and transports of wood chips
in this study (calculated from the initial data by Pingoud et al. 1999).
Production
Transportation
Total
kg CO2/GJ fuel energy (wood chips)
1.1
0.4
1.5
The specific CO2 emissions from a Swedish study (Vattenfall 1996) are presented in
Table 14. This study took the whole supply chain of wood chips into account (i.e. also
cutting and delimbing, which are not accounted for in Table 13, as the stemwood would
be produced anyway for pulp production).
In addition to CO2, methane (CH4) and nitrous oxide (N2O) emissions are produced.
The emissions from the logging machinery are not considered. For transportation, the
CH4 and N2O emissions can be calculated using the emission factors (0.06 g CH4/km
and 0.03 g N2O/km) given by IPCC (1997). The GHG emissions expressed in CO2
42
equivalents would be 10.6 g CO2 (eq)/km. The significance of the CH4 and N2O emissions is small.
Table 14. The specific CO2 emissions of the whole supply chain of wood chip production from forest residues and transportation (Vattenfall 1996).
Production
Transportation
Total
kg CO2/GJ fuel energy (wood chips)
2.1
0.5
2.6
Wihersaari (2000) has estimated, in a recent subproject of the Finnish Wood Energy
Technology Programme of Tekes, the total fuel chain greenhouse gas emissions for the
harvesting chain of logging residue and its transportation to a site at the distance of
40 km. The total energy consumption was estimated as 2–2.5 dm3 diesel/MWh wood
fuel energy (1.6–2.0 kg CO2(eq)/GJ wood chips). In the calculation of the fuel chain
greenhouse gas emissions in this study (see chapter 3.4) the mean value of this range,
1.8 kg CO2(eq)/GJ wood chips, is used for wood chips production and transportation.
2) The Far East case
In the case of fast growing coppices (eucalyptus) the fuel supply chain is different from
the Finnish forest residue collecting and chipping chain. Eucalyptus is cultivated as a
dense field and harvested as whole. The growth is much faster than the forest growth in
Finland, e.g., in Brazil typically six to seven years, when eucalyptus is cultivated for use
in cellulose production (Hakkila et al. 1992). This means that fertilisers are used to enhance the growth, which leads to emissions of nitrous oxide (N2O). The greenhouse gas
emissions due to fertiliser production also need to be considered.
The emissions caused by the fertilisation of the eucalyptus cultivation are estimated as
follows: Approximately 600 kg NPK fertiliser (15% nitrogen) per ha is assumed to be
applied during a rotation period of 7 years1. Mean growth is estimated as 35 m3ha–1a–1
and the density of eucalyptus to be 500 kgm–3. The N2O emissions are calculated using
IPCC default emission factor: 1.25% of the nitrogen content of the fertiliser emitted as
N2O. Greenhouse gas emission from fertiliser production, transportation and spreading
are estimated to be 550 kg CO2(eq)/t fertiliser. The total emissions from fertiliser use
would then be approximately 0.007 kg CO2(eq)/kg wood (0.9 kg CO2(eq)/GJ).
1
Seppo Vuokko, Stora Enso, personal communication, 19 May 2000.
43
The emissions from eucalyptus harvesting and transport to the production site are calculated as in the Finnish case, but the emissions caused by fertilisation are also added
when summarising the fuel chain GHG emissions. The greenhouse gas emissions estimates for eucalyptus cultivation and harvesting are rather rough because of minor data
available.
3.1.2.3 Emissions from the methanol production integrated to the pulp mill
As mentioned before, the bark boiler does not require any supplementary fuel in this
specific case, because the combustible by-products and steam from the methanol production process cover the additional demand of electricity and steam. This means that
no additional GHG emissions are produced in the bark boiler. In addition, because the
methanol production chain runs with synthesis gas from biomass (wood chips) gasification, no net CO2 emissions are produced from the production process either (sustainable
silviculture assumed).
The small amount of CH4 formed in gasification is reformed in the tar reformer, and
hence the negligible CH4 emissions to the atmosphere are not considered in the calculations.
The amount of surplus power from kraft pulp plant is reduced, when the methanol production plant is integrated to the existing bark boiler, slightly in the Finnish case and
30–40% in the Far East case (see Tables 4 and 5). This affects the total system costs but,
however, not directly the net GHG emission balances.
Because the methanol produced in the Far East is assumed to be used in Europe, the
GHG emissions from long-range sea transportation are also considered. The specific
GHG emissions from sea transportation are presented in Table 15.
Table 15. The specific GHG emissions (kg CO2(eq)/GJ heavy fuel oil (hfo)) from sea
transportation (IPCC 1997).
Ocean-going ships (diesel engines, heavy fuel oil)
CH4
Emission component
CO2
Global warming potential
1
21
Emission factor (kg/GJ)
77.6
0.007
N2O
310
0.002
NOx
1%
2.1
CO2(eq)
GWP100
85
Ecotraffic (1992) reports an energy consumption of 0.012 GJ hfo/GJ MeOH for longrange sea transportation of methanol. Hence, the total GHG emissions of shipping are
1.0 kg CO2(eq)/GJ MeOH shipped. This value is used for sea transportation when summarising the total fuel chain GHG emissions in the Far East case (see chapter 3.4).
44
3.1.3 Gasoline and diesel production from crude oil
Gasoline and diesel production is also considered here in order to compare the fuel
chain emissions between biomass-based methanol and gasoline. The greenhouse gas
emissions for gasoline production from crude oil (North Sea production) are presented
in Table 16.
Table 16. GHG emissions for gasoline refined from crude oil (IEA/AFIS 1996).
Fuel chain step
Crude oil production *
Transportation **
Refining
Total fuel chain (prod., transp. and ref.)
Specific emission [kg CO2(eq)/GJ]
0.87
0.15–2.45
2–3.7
3.0–7.0
* North Sea production
** min: North Sea – Rotterdam – North Sea; max: Persian Gulf – Rotterdam – Persian Gulf
Allocation of the aggregate emissions from crude oil production and refining to individual products cannot be made accurately as several of the processes are common to several products, the yields of which vary from case to case. However, in Table 17, ranges
for CO2 emissions allocated to gasoline and diesel for different steps in the production
chain are given based on the reference (IEA/AFIS 1999).
Life cycle CO2 emissions from reformulated gasoline refined from crude oil and used in
passenger cars in Finland, given by Fortum Oil & Gas (former Neste), are presented in
Table 18. It can be seen that the end-use produces almost ten times more CO2 emissions
per litre gasoline than the whole fuel production chain. The corresponding life cycle
CO2 emissions from city-diesel are presented in Table 19.
The IEA/AFIS (1996) values in Table 16 were used in the calculation of the total fuel
chain greenhouse gas emissions in this study (see chapter 3.4).
Table 17. CO2 emissions of gasoline and diesel refined from crude oil (IEA/AFIS 1999).
A. Feedstock
production
Gasoline
Diesel
CO2, min
kg/GJ
1.8
1.7
CO2, max
kg/GJ
3.4
3.4
B. Feedstock transportation
Gasoline
Diesel
CO2, min
kg/GJ
0.6
0.6
CO2, max
kg/GJ
0.6
0.6
C. Fuel production
Gasoline
Diesel
CO2, min
kg/GJ
6.1
3.0
CO2, max
kg/GJ
12
7.0
D. Total Fuel production chain
Gasoline
Diesel
CO2, min
kg/GJ
8.5
5.3
CO2, max
kg/GJ
16
11
45
Table 18. CO2 emissions of reformulated gasoline refined from crude oil (Fortum Oil &
Gas 1999).
Life cycle emissions of gasoline (Neste)
Heat value 32,1 MJ/l
Density
745 kg/m3
Emission per
gasoline
volume
g CO2/l
Crude oil production, transportation, refining and delivery
Use in passenger car
TOTAL
Emission per
gasoline
mass
g CO2/kg
Heat value Emission per
of gasoline energy content
MJ/kg
of gasoline
kg CO2/GJ
260
349
43.1
8.1
2 350
2 610
3 154
3 503
43.1
73.2
81.3
Table 19. CO2 emissions of city-diesel refined from crude oil (Fortum Oil & Gas 1999).
Life cycle emissions of diesel fuel (Neste)
Heat value 35.9 MJ/l
Density 835 kg/m3
Emission per
diesel
volume
g CO2/l
Crude oil production, transportation, refining and delivery
Use in passenger car/van/HDV
TOTAL
Emission per
diesel
mass
g CO2/kg
Heat value Emission per
of diesel energy content
MJ/kg
of diesel
kg CO2/GJ
190
228
43.0
5.3
2 650
2 840
3 174
3 401
43.0
73.8
79.1
3.1.4 Hydrogen production from biomass
The greenhouse gas emissions for hydrogen production from biomass and its use in fuel
cell vehicles are also estimated, but the emission estimates are based on rougher data.
The hydrogen production is integrated to the kraft pulp mill in the same way as the
methanol production described earlier. Only the Finnish case is studied, i.e. the gasification facility of 100 MW wood chips (334 000 t/a). The hydrogen yield is somewhat
greater than in the case of methanol. Again, no net CO2 emissions are produced and the
emissions of CH4 and N2O are negligible. Also hydrogen production from electrolysis
of water is considered roughly for reference.
The energy efficiencies used are estimated based on IEA/AFIS (1999) for electrolysis
and process calculations in Ch. 2.5 for steam reforming/gasification of biomass. For
electrolysis, average emissions for biomass-based electricity (4 g CO2(eq)/MJ) and
46
average power mix of Finland (250 g CO2/kWh) are used in the calculations. For steam
reforming, the emissions of raw material production (biomass and natural gas)
calculated in the other cases are used.
For sea transportation of hydrogen, IEA/AFIS (1996) gives an energy consumption
value of (0.06 GJ/GJ) that is used in calculation (see Ch. 3.4).
3.2 Local distribution
Liquid methanol can be distributed for consumption like gasoline. If the tank trucks use
petroleum fuels (i.e. diesel), the greenhouse gas emissions can be calculated by using
emission factors given in literature. If the biomass-based methanol fuel were also used
in tank trucks, the methanol fuel distribution would not cause any additional net carbon
dioxide emissions. This alternative is, however, not considered here.
Hydrogen distribution requires special transportation equipment. A new infrastructure
for the hydrogen distribution network would be expensive. For greenhouse gas emission
calculations of hydrogen sea transportation and local distribution the energy consumption values (0.06 GJ hfo/GJ hydrogen shipped and 0.11 GJ diesel/GJ hydrogen distributed, respectively) from the reference IEA/AFIS (1996) are used.
The greenhouse gas emissions from gasoline, methanol and hydrogen transportation in
trucks must be calculated so that the differences in distribution mileage are also taken
into account. The distribution mileage is greater for methanol than for gasoline due to
its lower density and heat value (i.e. the same energy content of methanol needs more
transportation volume than gasoline). The energy consumption values of fuel distribution used here include these differences.
The specific energy consumption figures of local fuel distribution for different fuels are
presented in Table 19. Fugitive energy losses are also included in most cases. When
overseas transportation is needed (e.g. for hydrogen distribution), the specific energy
consumption of sea tankers must be added (e.g. 0.06 GJ hfo/GJ for hydrogen and 0.012
GJ hfo/GJ for methanol, Ecotraffic 1992) to the figures in Table 19.
In the calculation of the total fuel chain greenhouse gas emissions (see chapter 3.4) the
values of Ecotraffic (1992) in Table 20 were used for fuel distribution.
47
Table 20. Specific energy consumption of local fuel distribution for different automotive
fuels.
Fuel distribution
Reference:
Gasoline
Diesel
Natural gas
Methanol
Hydrogen
GJ/GJ
ETSU
UK, 1995
0.002
0.03
0.010
Energy consumption
GJ/GJ
GJ/GJ
Ecotraffic
DeLuchi
Sweden, 1992 USA, 1991
0.010
0.0083
0.010
0.0091
0.09
0.086
0.010
0.11
The minimum and maximum specific carbon dioxide emissions (IEA/AFIS 1999) of
local fuel distribution are presented in Table 21.
Table 21. The minimum and maximum specific CO2 emissions of local fuel distribution
for different automotive fuels (IEA/AFIS 1999).
Fuel distribution
Reference:
Gasoline
Diesel
Natural gas
Methanol
Hydrogen
CO2, min
CO2, max
kg/GJfuel
kg/GJfuel
IEA, AFIS, 1999
0.2
0.7
0.2
0.7
1.4
11.2
0.4
2.7
1.5
5.4
The local distribution is in most cases done by diesel fuelled road tankers. The GHG
emissions of diesel fuelled HDV are calculated in Table 22.
Table 22. The GHG emissions of diesel fuelled HDV (Wihersaari 2000).
CO2
1
2 660
CH4
21
0.3
GHG emission (HDV)
Density, diesel fuel
LHV, diesel fuel
LHV, diesel fuel
GHG emission
N2O
310
0.1
2.8
0.835
43
35.9
78.6
NOx
1%
40
CO2 (eq)
GWP100
2 821
g/l diesel
kg CO2 (eq)/l diesel
kg/l
MJ/kg
MJ/l diesel
kg CO2(eq)/GJ diesel
For comparison, corresponding emissions calculated with IPCC default values (IPCC
1997) would amount to 75.1 kg CO2(eq)/GJ.
48
3.3 Use in vehicles
Emissions originating from the vehicle stage were determined using vehicle parameters
and assumed total powertrain efficiencies to determine the gross energy use and actual
fuel usage. This stage incorporated emissions only from the direct use of fuel, i.e. not
from refuelling at the filling stations.
The carbon dioxide emissions from fuel cell vehicles fuelled with biomass-derived neat
methanol (M100) are not taken into account. Biomass-derived M85 fuel (fuel blend
containing 85% methanol and 15% gasoline) used in hybrid vehicles (combination of
internal combustion engine (ICE) and electric motor/generator) produces fossil carbon
dioxide emissions in proportion to the mass of gasoline in the fuel. The CO2 emissions
from biomass-derived methanol are not added to the estimated GHG emissions.
3.3.1 Vehicles
Emissions of GHGs from the vehicle use were determined for three different cases:
family cars, urban commuters and urban buses. The primary case was a family car, with
five seats and approximated net weight (excluding powertrain and fuel) of 800 kg. The
target output of the powertrain was set at 50 kW, delivering the maximum speed of approximately 150 km/h. The target range was established at 600 km (200 km for pure
battery EV) yielding in different sizes for fuel tank depending on the fuel’s energy density. The total gross vehicle weight was in the range of 1 260–1 315 kg depending on
the powertrain type and on the amount of fuel on-board that was sufficient to reach the
targeted range. The other car under consideration was a small urban commuter with two
seats and only 200 km range (100 km for pure battery EV) and power output of 20 kW.
Table 23 lists the basic vehicle parameters.
The third case, urban bus, was considered to have a capacity for 50 persons, net weight
of 7 000 kg and target range 400 km. The powertrain output was assumed to be 250 kW.
With a sufficient amount of fuel onboard, the gross vehicle mass was around 13 500 kg.
Table 23. Basic vehicle parameters.
Case
Family car
Urban commuter
Urban bus
*
Net weight
(kg)
800
400
7 000
Gross weight Power output
(kg)
(kW)
*
~ 1 300
50
~ 725*
20
~ 13 600*
250
average, actual value depending on configuration
49
Max. speed
(km/h)
150
100
80
Target range
(km) [EV]
600 [200]
200 [100]
n/a
3.3.2 Powertrains
Four types of powertrains were considered for both vehicles. The basic one was a sparkignition internal combustion engine (ICE), either spark-ignited (otto, SI) or compression-ignited (diesel, CI). A more advanced case was a hybrid-drive with an ICE and
some type of electric storage buffer for regenerated energy (ICE-SI/H or ICE-CI/H).
The third option was a fuel cell drive (FC) either with direct hydrogen on-board or with
a fuel processor (reformer) for hydrogen production. Two types of reformers were compared, steam reformer (STM) and partial oxidation type (POX). STM was considered
suitable for using methanol as feedstock, and POX reformer was considered for gasoline
(RFG). The fourth powertrain option was a battery powered pure electrical vehicle
(EV). Table 24 lists assumed efficiencies for the different powertrain options. These
assumptions are quite general, and were made using recently published data in Docter &
Lamm (1999), Karlhammer et al. (1998), Ogden et al. (1999), Stodolsky et al. (1999),
and Thomas (1999).
Table 24. Assumed efficiencies for the different powertrain options.
Powertrain type
Part load / full load ratio, %
Fuel reformer efficiency, %
95
n/a
ICE
-SI
34
351
70
n/a
Mechanical drivetrain eff., %
Hybrid drivetrain gains, %
80
125
80
100
80
100
80
120
80
120
Powertrain total efficiency, %
90
19
26
25
261
31
Net engine efficiency, %
1
2
Pure
EV
95
ICE
-CI
40
80
n/a
ICE- ICESI/H CI/H
34
40
351
80
80
n/a
n/a
FC+
FCreformer Direct H2
60
60
95
51 STM
57 POX
80
120
31 STM
28 POX
95
n/a
80
120
1002
54
452
methanol allows higher compression ratio => increased net efficiency
direct FC-EV drive, no regenerative braking
3.3.3 Fuels
Theoretically, neat methanol can be used as fuel for ICE, but for safety reasons it is usually blended with gasoline. It ensures cold start and gives the necessary luminosity for
the flame. A typical composition for vehicle distribution is M85, i.e. 15% gasoline in
methanol. Gasoline in current reformulated quality that includes 10% of MTBE, was
considered as the base case. For fuel cell vehicles, the fuel choices were neat methanol
(M100) or RFG, although in reality a single-component hydrocarbon fuel rather than a
blend would be the ideal feedstock for the reformer.
50
3.3.4 Energy consumption
The energy consumption for all vehicles was computed using the ICE vehicle with RFG
(or diesel for the urban bus case) as the reference case. The family car with a regular
ICE powertrain yielded a gross vehicle weight (GVW) of 1 281 kg, and for a mixed
type of driving, fuel consumption (RFG) was approximated to be 7 dm3/100 km. With
the estimated powertrain total efficiency of 19%, the net energy required to move this
type of vehicle was 0.414 MJ/km (or 0.00032 MJ/km*kg). For the urban commuter the
base case was a similar ICE powertrain, but because of a lower GVW (712 kg) and
slow-speed driving, fuel (RFG) consumption was set at 3.5 dm3/100 km. This gave
0.222 MJ/km (or 0.00031 MJ/km*kg) for basic energy use.
The urban bus case was calibrated for 55 dm3/100 km consumption, giving 5.22 MJ/km
or 0.00039 MJ/km*kg, for the energy requirement, as the respective GVW was
13 335 kg.
The net energy requirement for the other cases was then computed using these figures as
the basis considering different GVWs. From these values the final gross energy use was
then determined using the estimated total efficiency figures for each of the powertrain
cases. The calculated fuel use and gross energy values for the different vehicle and
powertrain types are presented in Tables 25 and 26.
Table 25. Actual fuel use (dm3/100 km) for different vehicle and powertrain types.
ICE-SI / ICE-CI
Fuel consumption
[dm3/100
km]
Gasoline
(RFG)
M85
Citydiesel
(RFD in
LDVs)
M100 in
diesel LDVs
M100 in fuel
cell
Hydrogen
(medium size
class)
RFG/M85 or
RFD/M100
Fam. Urban
car
comm.
ICE-hybrid
Fuel cell vehicle (regeneration)
Steam
reformer
M100
POX
Hydrogen
RFG/M85 or
RFG
H2
RFD/M100
Fam. Urban Fam. Urban Fam. Urban Fam. Urban
car comm. car comm. car comm. car comm.
7.0
3.5
5.4
2.7
12.4
4.4
6.3
2.4
9.2
3.8
4.8
2.1
10.6
5.8
9.0
5.1
5.0
9.4
3.4
5.1
7.6
Note: the fuel use [dm3/100 km] refers to the case fuel; i.e. RFG, RFD, M100, H2
51
4.2
Table 26. Gross energy values (MJ/km) for different vehicle and powertrain types.
ICE-SI / ICE-CI
Gross
energy use
MJ/km
Gasoline
(RFG)
M85
Citydiesel
(RFD in
LDVs)
M100 in diesel LDVs
M100 in fuel
cell
Hydrogen
Electrical
vehicle (EV)
ICE-hybrid
Fuel cell vehicle (regeneration)
(medium size
class)
RFG/M85 or
RFD/M100
Fam. Urban
car
comm.
Steam
reformer
M100
POX
RFG/M85 or
RFG
H2
RFD/M100
Fam. Urban Fam. Urban Fam. Urban Fam. Urban
car comm. car comm. car comm. car comm.
2.18
1.09
1.68
0.85
2.22
1.60
1.12
0.89
1.65
1.37
0.85
0.77
1.63
0.90
1.39
0.78
1.60
1.44
Hydrogen
1.09
0.78
0.81
0.51 (for family car)
0.44
0.41 (for urban commuter)
3.3.5 Emissions
The GHG emissions derived from vehicle use considered here were CO2, CH4 and N2O.
Direct CO2 from fuel combustion was calculated from the carbon content of the fuel.
Specific emissions for CH4 and N2O were determined first for the reference case (ICESI, RFG), and then a relative figure was established for the various optional powertrain
and fuel combinations.
Apart from these GHGs, an estimate for specific NOx emission was also established.
Table 27 outlines the assumed specific emission rates for the base case (ICE-SI, RFG).
Table 27. Assumed specific emission rates for the base case (ICE-SI, RFG).
Fuel use [dm3/100 km]
Gross energy use [MJ/km]
direct CO2 [g/km]
N2O [g/km]
CH4 [g/km]
NOx [g/km]
7.0
2.18
163
3.13 kg/kgfuel
GWP values
310
21
n/a
0.03
0.02
0.08
52
Estimated
Calculated
Calculated
Est., CORINAIR (2005)
10% of EU4 HC (2005)
EU4 standard (2005)
Table 28 summarises the relative emissions estimated for different powertrain options.
Table 28. The relative emissions estimated for different powertrain options.
powertrain
fuel
N2O [g/MJgross]
CH4 [g/MJgross]
ICE-SI
ICE-SI ICE-SI/H ICE-SI/H
RFG
M85
RFG
M85
100 %
100 %
100 %
100 %
N2O is only catalyst dependent
100 %
50 %
50 %
50 %
less
less
MeOH
transients
transients
less
volatile on hybrid on hybrid
FC
n/a
n/a
drive, better drive, better
control of
control of
emissions
emissions
NOx [g/km]
100 %
100 %
50 %
50 %
n/a
less
less
transients
transients
on hybrid
on hybrid
drive, better drive, better
control of
control of
emissions
emissions
3.4 Fuel chain GHG emissions for the selected cases
The total fuel chain emissions from fuel production to end use in vehicles are summarised for the different fuels in the following sub-chapters. In addition to CO2, the CH4
and N2O emissions are considered. The emissions from manufacturing the vehicles,
power plants, etc. are not considered. In the sub-chapters the fuel chain emissions are
presented separately for fuel production (including distribution) and end use in vehicles.
The GHG emissions for the different fuel production chains (including transportation
and distribution of the fuel) are summarised in Table 29. The GHG emissions
(kg CO2(eq)/GJ) of the fuel production chains have been converted to g/km emissions
with gross energy use values (MJ/km) of specific vehicle types and summarised with
end use GHG emissions.
Table 29. The summarised GHG emissions (kg CO2(eq)/GJ fuel) from fuel production
chains (including delivery, see chapters 3.1–3.2 for details).
RFG from crude
MeOH from
natural gas
Conv. Biomass- M100 M85
MeOH in
MTBE
6.8
6.7
10
11.2
M100 from
Electricity production Hydrogen (no sea
biomass
transport.)
FinFar Finland, EU,
From ElecSteam
land East average average bio- trolysis, ref.,
(esti- mass average biomass
mate)
power
3.8
5.8
83
111
7
120.6
11.6
53
3.4.1 CASE 1: Reference cases (gasoline and diesel in LDVs)
Reformulated gasoline (RFG) in light-duty vehicles (95E, 10% MTBE (methanol from
natural gas))
The total fuel chain GHG emissions of reformulated gasoline (RFG) production, delivery and end use in ICE-SI family car (medium size class) and in the urban commuter
(city-car) are presented in Table 30.
The GHG emission of gasoline fuel production chain is about 15 g CO2(eq)/km when
used in the present-type ICE-SI car. The fuel use in vehicles produces
173 g CO2(eq)/km with a gasoline consumption of 7 l/100 km or 33.6 mpg, and the total
GHG emissions are then 188 g CO2(eq)/km. The use of gasoline in vehicles produces
over 90% of the total well-to-wheel GHG emissions.
Table 30. The summary of fuel chain GHG emissions (g/km) of LDVs using reformulated gasoline (RFG) produced from crude oil.
ICE-SI, RFG
GHG TOTAL (g CO2(eq)/km))
A. RFG fuel production chain
A1. Family car (5 seats, 50 kW)
A2. Urban commuter (2 seats, 20 kW)
B. End use in vehicles (net CO2(eq))
B1. Family car (5 seats, 50 kW)
B2. Urban commuter(2 seats, 20 kW)
g CO2(eq)/km
15
7
g CO2(eq)/km
173
86
FUEL CHAIN GHG, TOTAL
1. Family car (5 seats, 50 kW)
2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
188
94
If RFG is used in ICE-SI urban commuters (2 seats, 20 kW, see Ch. 3.3), the total GHG
emissions are reduced to 94 g CO2(eq)/km. The emissions from the use of RFG in ICEhybrid or fuel cell vehicles were also calculated for reference for the following cases
(see Table 50).
Diesel use in light-duty vehicles
The total fuel chain GHG emissions for reformulated diesel (RFD, citydiesel) production, delivery and use in the ICE-CI family car (medium size class) and in the urban
commuter (city-car) are presented in Table 31a. A hybrid car using diesel fuel is also
considered (Table 31b).
54
The GHG emissions of diesel fuel production chain are about 10 g CO2(eq)/km when
used in the present-day type ICE-CI car. The end use produces 119 g CO2(eq)/km with a
diesel consumption of 5.0 l/100 km, and the total GHG emissions are then
130 g CO2(eq)/km. When RFD is used in the ICE-CI urban commuter (2 seats, 20 kW,
see Ch. 3.3), the total GHG emissions are reduced to 72 g CO2(eq)/km.
When diesel is used in ICE-CI/H hybrid cars, the GHG emissions are slightly reduced:
111 and 63 g CO2(eq)/km for the family car and the urban commuter, respectively. This
is due to the reduced gross energy use – and hence, diesel consumption – because of the
electric storage buffer for regenerated energy (i.e. from braking).
Table 31a. The summary of fuel chain GHG emissions (g/km) of ICE-CI LDVs using
reformulated diesel (RFD) produced from crude oil.
a. ICE-CI, citydiesel RFD
GHG TOTAL (g CO2(eq)/km))
A. RFD fuel production chain
A1. Family car (5 seats, 50 kW)
A2. Urban commuter(2 seats, 20 kW)
B. End use in vehicles (net CO2(eq))
B1. Family car (5 seats, 50 kW)
B2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
10
6
g CO2(eq)/km
119
66
FUEL CHAIN GHG, TOTAL
1. Family car (5 seats, 50 kW)
2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
130
72
Table 31b. The summary of fuel chain GHG emissions (g/km) of hybrid LDVs using
reformulated diesel (RFD) produced from crude oil.
b. hybrid, citydiesel (RFD)
GHG TOTAL (g CO2(eq)/km))
A. RFD fuel production chain
A1. Family car (5 seats, 50 kW)
A2. Urban commuter (2 seats, 20 kW)
B. End use in vehicles (net CO2(eq))
B1. Family car (5 seats, 50 kW)
B2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
9
5
g CO2(eq)/km
102
58
FUEL CHAIN GHG, TOTAL
1. Family car (5 seats, 50 kW)
2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
111
63
55
3.4.2 CASE 2: MTBE from wood-derived MeOH (gasoline in LDVs)
If the MTBE additive for reformulated gasoline is produced from wood-based methanol
rather than from natural gas based methanol, the net carbon dioxide emissions are reduced. This reduction is rather small because there is only 10% MTBE in RFG and
moreover, only 20% of the carbon content in MTBE comes from methanol. Because of
limited biomass resources (see Ch. 4), the MTBE production from biomass-based
methanol could still be justified.
The full fuel chain GHG emissions of RFG containing biomass-based MTBE production, delivery and end use in the ICE-SI family car (medium size class) and in the urban
commuter (city-car) are presented in Table 33. The emissions from RFG (MTBE from
biomethanol) use in ICE-hybrid and fuel cell vehicles were also calculated for reference
(see Table 50).
It can be seen from Tables 30 and 32 that the fuel chain GHG emissions of RFG with
MTBE from biomass-based methanol are reduced by less than 2% (185 vs.
188 g CO2(eq)/km) compared to conventional RFG with MTBE from natural gas based
methanol. In urban commuters this reduction is even smaller (about 1%, 94 vs.
93 g CO2(eq)/km) due to lower fuel consumption.
Table 32. The summary of fuel chain GHG emissions (g/km) of ICE-SI Family cars using
reformulated gasoline (RFG), which include MTBE from biomass-based methanol.
ICE-SI, RFG (medium size class)
GHG TOTAL (g CO2(eq)/km))
A. RFG fuel production chain
A1. Family car (5 seats, 50 kW)
A2. Urban commuter (2 seats, 20 kW)
B. End use in vehicles (net CO2(eq))
B1. Family car (5 seats, 50 kW)
B2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
14
7
g CO2(eq)/km
171
85
FUEL CHAIN GHG, TOTAL
1. Family car (5 seats, 50 kW)
2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
185
93
56
3.4.3 CASE 3: MeOH (both from biomass and natural gas) in fuel cell
vehicles
3.4.3.1 Biomass
1) The Finnish case
The total fuel chain greenhouse gas emissions of light-duty fuel cell vehicles using neat
methanol (M100) produced from biomass (pine chips) are listed in Table 33. Carbon
dioxide emissions from fuel cells are not considered, when the methanol fuel is made
from biomass. The total GHG emissions are then composed only of emissions from the
methanol production and distribution.
When biomass-based M100 is used in a fuel cell vehicle of family car size class, the
total GHG emissions are 6 g CO2(eq)/km (with M100 consumption of 4.5 l/100 km or
51.8 mpg), whereas the use in an urban commuter fuel cell vehicle (2 seats, 20 kW, see
Ch. 3.3) produces total GHG emissions of 3 g CO2(eq)/km. These fuel chain GHG
emissions are only 3 and 2%, respectively, of the fuel chain emissions of reference case
(RFG in ICE-SI Family car, Ch. 3.4.1).
Table 33. Fuel chain GHG emissions of fuel cell vehicles using neat methanol (M100)
produced from biomass (Finland).
Fuel cell, M100 (Steam reformer)
GHG TOTAL (g CO2(eq)/km))
A. Methanol fuel production chain
A1. Family car (5 seats, 50 kW)
A2. Urban commuter (2 seats, 20 kW)
B.
End use in vehicles (net CO2(eq))
B1. Family car (5 seats, 50 kW)
B2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
6
3
g CO2(eq)/km
0
0
FUEL CHAIN GHG, TOTAL
1.
Family car (5 seats, 50 kW)
2.
Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
6
3
2) The Far East case
For eucalyptus harvesting and transportation, the same energy losses and emissions as
in the Finnish case (pine) are assumed. In addition, the emissions of sea transport of
methanol from the Far East to Europe are considered. Fertiliser use in the plantations
also causes GHG emissions (mostly N2O, see Ch. 3.2.1).
57
In Table 34, the total GHG emissions of M100 produced in the Far East and shipped to
Europe, and used in fuel cell vehicles of family car and urban commuter size classes are
presented.
Tables 32 and 34 show that the total fuel chain GHG emissions are increased by 1–
2 g/km due to eucalyptus fertilising and sea transportation of methanol. Even so, the
fuel chain GHG emissions are still only 4 and 2% for the family car and the urban
commuter, respectively, of the fuel chain emissions of the reference case (RFG in ICESI family car, Ch. 3.4.1). This indicates that it would be totally reasonable to produce
biomass-based methanol in areas of fast growing biomass and use it elsewhere. However, the cost of long-range sea transportation would be a problem, at least until the
production costs of biomass-based methanol can be reduced to the cost level of RFG
production.
Table 34. Fuel chain GHG emissions of fuel cell vehicles using neat methanol (M100)
produced from eucalyptus in the Far East and transported to Europe for end use.
Fuel cell, M100 (Steam reformer)
GHG TOTAL (g CO2(eq)/km))
A. Methanol fuel production chain
A1. Family car (5 seats, 50 kW)
A2. Urban commuter (2 seats, 20 kW)
B.
End use in vehicles (net CO2(eq))
B1. Family car (5 seats, 50 kW)
B2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
8
4
g CO2(eq)/km
0
0
FUEL CHAIN GHG, TOTAL
1.
Family car (5 seats, 50 kW)
2.
Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
8
4
3.4.3.2 Natural gas
The total fuel chain greenhouse gas emissions of light-duty fuel cell vehicles using neat
methanol (M100) produced from natural gas are listed in Table 35. As the methanol is
now produced from a fossil raw material, also the CO2 emissions from use in fuel cells
are considered and the total emissions are therefore much larger than in the case of
biomethanol.
The GHG emissions from natural gas based M100 fuel production and distribution are
about 14 g CO2(eq)/km when using the fuel in fuel cell vehicles of family car size class.
The end use produces 102 g CO2(eq)/km (with M100 consumption of 4.5 l/100 km or
51.8 mpg), and the total GHG emissions are then 117 g CO2(eq)/km. If the natural gas
based M100 is used in fuel cell vehicles of urban commuter size class (2 seats, 20 kW,
see Ch. 3.3), the total GHG emissions are reduced to 63 g CO2(eq)/km.
58
Table 35. Fuel chain GHG emissions of fuel cell vehicles using neat methanol (M100)
produced from natural gas.
Fuel cell, M100 (Steam reformer)
GHG TOTAL (g CO2(eq)/km))
A. Methanol fuel production chain
A1. Family car (5 seats, 50 kW)
A2. Urban commuter (2 seats, 20 kW)
B. End use in vehicles (net CO2(eq))
B1. Family car (5 seats, 50 kW)
B2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
14
8
g CO2(eq)/km
102
55
FUEL CHAIN GHG, TOTAL
1. Family car (5 seats, 50 kW)
2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
117
63
These total fuel chain GHG emissions are 62 and 34%, respectively, of the fuel chain
emissions of the reference case (RFG in ICE-SI family car, Ch. 3.4.1). In these cases,
the end use produces 87% of the total fuel chain GHG emissions compared to over 90%
in the reference case.
3.4.4 CASE 4: Methanol use in ICE-hybrid vehicles
3.4.4.1 Biomass
1) The Finnish case
The total fuel chain greenhouse gas emissions of ICE-hybrid vehicles using M85, i.e.
methanol (85%) blended with gasoline (15%), produced from forest residues in Finland
are listed in Table 36.
The GHG emissions of the biomass-based M85 fuel production chain are about
7 g CO2(eq)/km if used in a hybrid vehicle of family car size class. The end use produces 41 g CO2(eq)/km (with M85 consumption of 5.2 l/100 km or 44.9 mpg), and the
total GHG emissions are 49 g CO2(eq)/km. If the biomass-based M85 is used in a hybrid vehicle of urban commuter size class (2 seats, 20 kW, see Ch. 3.3), the total GHG
emissions are reduced to 25 g CO2(eq)/km. These fuel chain GHG emissions are 26 and
13%, respectively, of the fuel chain emissions of reference case (RFG in ICE-SI Family
car, Ch. 3.4.1).
For diesel ICE-hybrid vehicles using neat methanol (M100) produced from forest residues in Finland, the total fuel chain greenhouse gas emissions are 8 and 5 g/km for
59
family cars and urban commuters, respectively. These fuel chain GHG emissions are
only 4 and 2%, respectively, of the fuel chain emissions of the reference case (RFG in
ICE-SI family car, Ch. 3.4.1) and about 7–8% of the fuel chain emissions of ICE-hybrid
vehicles using conventional city-diesel fuel.
Table 36. Fuel chain GHG emissions of ICE-hybrid vehicles using methanol (M85)
produced from biomass (Finland).
Hybrid, M85
GHG TOTAL (g CO2(eq)/km))
A. Methanol fuel production chain
A1. Family car (5 seats, 50 kW)
A2. Urban commuter (2 seats, 20 kW)
B.
End use in vehicles (net CO2(eq))
B1. Family car (5 seats, 50 kW)
B2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
7
4
g CO2(eq)/km
41
21
FUEL CHAIN GHG, TOTAL
1.
Family car (5 seats, 50 kW)
2.
Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
49
25
2) The Far East case
In Table 37, the total GHG emissions of M85 (methanol produced in and shipped from
the Far East to Europe) used in hybrid vehicles of family car and urban commuter size
classes are presented.
Tables 36 and 37show that the total fuel chain GHG emissions for ICE-hybrid vehicles
using M85 are increased by 1–2 g/km due to the eucalyptus fertilising and sea transportation of methanol compared to the Finnish case. The fuel chain GHG emissions are 27
and 14%, for the family car and the urban commuter, respectively, of the fuel chain
emissions of reference case (RFG in ICE-SI family car, Ch. 3.4.1).
For diesel ICE-hybrid vehicles using neat methanol (M100) produced from biomass
(eucalyptus) in the Far East, the total fuel chain greenhouse gas emissions are 11 and
6 g/km for the family car and the urban commuter, respectively. These fuel chain GHG
emissions are only 6 and 3%, respectively, of the fuel chain emissions of the reference
case (RFG in ICE-SI Family car, Ch. 3.4.1) and about 10% of the fuel chain emissions
of ICE-hybrid vehicles using conventional city-diesel fuel.
60
Table 37. Fuel chain GHG emissions of ICE-hybrid vehicles using methanol (M85)
produced from biomass (the Far East).
Hybrid, M85
GHG TOTAL (g CO2(eq)/km))
A. methanol fuel production chain
A1. Family car (5 seats, 50 kW)
A2. Urban commuter (2 seats, 20 kW)
B.
End use in vehicles (net CO2(eq))
B1. Family car (5 seats, 50 kW)
B2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
10
5
g CO2(eq)/km
41
21
FUEL CHAIN GHG, TOTAL
1.
Family car (5 seats, 50 kW)
2.
Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
51
26
3.4.4.2 Natural gas
The total fuel chain greenhouse gas emissions of ICE-hybrid vehicles using methanol
(M85) produced from natural gas are listed in Table 38.
Table 38. Fuel chain GHG emissions of ICE-hybrid vehicles using methanol (M85)
produced from natural gas.
Hybrid, M85
GHG TOTAL (g CO2(eq)/km))
A. Methanol fuel production chain
A1. Family car (5 seats, 50 kW)
A2. Urban commuter (2 seats, 20 kW)
B. End use in vehicles (net CO2(eq))
B1. Family car (5 seats, 50 kW)
B2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
18
9
g CO2(eq)/km
126
65
FUEL CHAIN GHG, TOTAL
1. Family car (5 seats, 50 kW)
2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
145
75
The GHG emission of the natural gas based M85 fuel production chain is about
18 g CO2(eq)/km when used in a hybrid vehicle of family car size class. The end use
produces 126 g CO2(eq)/km (with M85 consumption of 5.2 l/100 km or 44.9 mpg), and
the total GHG emissions are 145 g CO2(eq)/km. If natural gas based M85 is used in the
hybrid vehicle of urban commuter size class (2 seats, 20 kW, see Ch. 3.3), the total
GHG emissions are reduced to 75 g CO2(eq)/km. These fuel chain GHG emissions are
77 and 40%, respectively, of the fuel chain emissions of the reference case (RFG in
ICE-SI Family car, Ch. 3.4.1).
61
For diesel ICE-hybrid vehicles using neat methanol (M100) produced from natural gas,
the total fuel chain greenhouse gas emissions are 115 and 65 g/km for the family car and
the urban commuter, respectively. These fuel chain GHG emissions are 61 and 34%,
respectively, of the fuel chain emissions of the reference case (RFG in ICE-SI Family
car, Ch. 3.4.1) and about 103–104% of the fuel chain emissions of ICE-hybrid vehicles
using conventional city-diesel fuel.
3.4.5 CASE 5: Methanol use in ICE vehicles (reference case)
3.4.5.1 Biomass
1) The Finnish case
The total fuel chain greenhouse gas emissions of ICE-SI vehicles using methanol (M85)
produced from forest residues in Finland are listed in Table 39.
Table 39. Fuel chain GHG emissions of ICE-SI vehicles using methanol (M85) produced from biomass (Finland).
ICE-SI, M85 (medium size class)
GHG TOTAL (g CO2(eq)/km))
A. Methanol fuel production chain
A1. Family car (5 seats, 50 kW)
A2. Urban commuter (2 seats, 20 kW)
B.
End use in vehicles (net CO2(eq))
B1. Family car (5 seats, 50 kW)
B2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
10
5
g CO2(eq)/km
55
28
FUEL CHAIN GHG, TOTAL
1.
Family car (5 seats, 50 kW)
2.
Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
65
33
The GHG emissions of the biomass-based M85 fuel production are about
10 g CO2(eq)/km when used in ICE-SI vehicle of family car size class. The end use
produces 55 g CO2(eq)/km (with M85 consumption of 7.1 l/100 km or 33.3 mpg), and
the total GHG emissions are 65 g CO2(eq)/km. If biomass-based M85 is used in the
ICE-SI vehicle of urban commuter size class (2 seats, 20 kW, see Ch. 3.3), the total
GHG emissions are reduced to 33 g CO2(eq)/km. These fuel chain GHG emissions are
35 and 18 per cent, respectively, of the fuel chain emissions of reference case (RFG in
ICE-SI Family car, Ch. 3.4.1).
For ICE-CI (diesel) vehicles using neat methanol (M100) produced from biomass the
total fuel chain greenhouse gas emissions are listed in Table 40.
62
Table 40. Fuel chain GHG emissions of ICE-CI (diesel) vehicles using neat methanol
(M100) produced from biomass (Finland).
ICE-CI, M100 in diesel vehicles
GHG TOTAL (g CO2(eq)/km))
A. Methanol fuel production chain
A1. Family car (5 seats, 50 kW)
A2. Urban commuter (2 seats, 20 kW)
B. End use in vehicles (net CO2(eq))
B1. Family car (5 seats, 50 kW)
B2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
6
3
g CO2(eq)/km
4
2
FUEL CHAIN GHG, TOTAL
1. Family car (5 seats, 50 kW)
2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
10
5
The GHG emissions of biomass-based M100 fuel production are about 6 g CO2(eq)/km
when used in the ICE-CI (diesel) vehicle of family car size class. The end use produces
4 g CO2(eq)/km (with M100 consumption of 5.1 l/100 km), and the total GHG emissions are 10 g CO2(eq)/km. If the biomass-based M100 is used in the ICE-CI vehicle of
urban commuter size class (2 seats, 20 kW, see Ch. 3.3), the total GHG emissions are
reduced to 5 g CO2(eq)/km. These fuel chain GHG emissions are only 5 and 3%, respectively, of the fuel chain emissions of reference case (RFG in ICE-SI Family car, Ch.
3.4.1) and about 7% of the fuel chain emissions of ICE-CI vehicles using conventional
city-diesel fuel.
2) The Far East case
The full fuel chain greenhouse gas emissions of ICE-SI vehicles using methanol (M85)
produced from biomass (eucalyptus) in the Far East are listed in Table 41.
It can be seen from Tables 39 and 41 that the total fuel chain GHG emissions for ICE-SI
vehicles using M85 are increased by 2–4 g/km due to the eucalyptus fertilising and sea
transportation of methanol compared to the Finnish case. The fuel chain GHG emissions
are 37 and 18%, for the family car and the urban commuter, respectively, of the fuel
chain emissions of the reference case (RFG in ICE-SI family car, Ch. 3.4.1).
For the ICE-CI (diesel) vehicles using neat methanol (M100) produced from biomass
(eucalyptus) in the Far East the total fuel chain greenhouse gas emissions are given in
Table 42.
63
Table 41. Fuel chain GHG emissions of ICE-SI vehicles using methanol (M85) produced from biomass (the Far East).
ICE-SI, M85 (medium size class)
GHG TOTAL (g CO2(eq)/km))
A. Methanol fuel production chain
A1. Family car (5 seats, 50 kW)
A2. Urban commuter (2 seats, 20 kW)
B.
End use in vehicles (net CO2(eq))
B1. Family car (5 seats, 50 kW)
B2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
13
7
g CO2(eq)/km
55
28
FUEL CHAIN GHG, TOTAL
1.
Family car (5 seats, 50 kW)
2.
Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
69
35
Table 42. Fuel chain GHG emissions of ICE-CI (diesel) vehicles using neat methanol
(M100) produced from biomass (the Far East).
ICE-CI, M100 in diesel vehicles
GHG TOTAL (g CO2(eq)/km))
A. Methanol fuel production chain
A1. Family car (5 seats, 50 kW)
A2. Urban commuter (2 seats, 20 kW)
B. End use in vehicles (net CO2(eq))
B1. Family car (5 seats, 50 kW)
B2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
9
5
g CO2(eq)/km
4
2
FUEL CHAIN GHG, TOTAL
1. Family car (5 seats, 50 kW)
2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
13
7
It can be seen from Tables 40 and 42, that the total fuel chain GHG emissions for diesel
vehicles using M100 are increased by 2–3 g/km due to eucalyptus fertilising and sea
transportation of methanol compared to the Finnish case. The fuel chain GHG emissions
are 7 and 4% for the family car and the urban commuter, respectively, of the fuel chain
emissions of the reference case (RFG in ICE-SI Family car, Ch. 3.4.1), and about 10%
of the fuel chain emissions of the ICE-CI Family car using conventional city-diesel fuel.
3.4.5.2 Natural gas
The total fuel chain greenhouse gas emissions of ICE vehicles using methanol (M85)
produced from natural gas are listed in Table 43.
64
Table 43. Fuel chain GHG emissions of ICE vehicles using methanol (M85) produced
from natural gas.
ICE-SI, M85 (medium size class)
GHG TOTAL (g CO2(eq)/km))
A. Methanol fuel production chain
A1. Family car (5 seats, 50 kW)
A2. Urban commuter (2 seats, 20 kW)
B. End use in vehicles (net CO2(eq))
B1. Family car (5 seats, 50 kW)
B2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
25
13
g CO2(eq)/km
170
86
FUEL CHAIN GHG, TOTAL
1. Family car (5 seats, 50 kW)
2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
195
98
The GHG emissions of natural gas based M85 fuel production amount to about
25 g CO2(eq)/km when used in an ICE-SI vehicle of family car size class. The end use
produces 170 g CO2(eq)/km (with M85 consumption of 7.1 l/100 km or 33.3 mpg), and
the total GHG emissions are 195 g CO2(eq)/km. If natural gas based M85 is used in the
ICE-SI vehicle of urban commuter size class (2 seats, 20 kW, see Ch. 3.3), the total
GHG emissions are reduced to 98 g CO2(eq)/km. These fuel chain GHG emissions are
104 and 52%, respectively, of the fuel chain emissions of reference case (RFG in ICESI Family car, Ch. 3.4.1), i.e., the total fuel chain emissions are increased by 4% compared to the RFG use.
For ICE-CI (diesel) vehicles using neat methanol (M100) produced from natural gas in
the Far East the total estimated fuel chain greenhouse gas emissions are in Table 44.
Table 44. Fuel chain GHG emissions of ICE-CI (diesel) vehicles using neat methanol
(M100) produced from natural gas.
ICE-CI, M100 in diesel vehicles
GHG TOTAL (g CO2(eq)/km))
A. Methanol fuel production chain
A1. Family car (5 seats, 50 kW)
A2. Urban commuter (2 seats, 20 kW)
B. End use in vehicles (net CO2(eq))
B1. Family car (5 seats, 50 kW)
B2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
16
9
g CO2(eq)/km
119
66
FUEL CHAIN GHG, TOTAL
1. Family car (5 seats, 50 kW)
2. Urban commuter (2 seats, 20 kW)
g CO2(eq)/km
135
75
65
The GHG emissions of natural gas based M100 fuel production are about
16 g CO2(eq)/km when used in the ICE-CI (diesel) vehicle of family car size class. The
end use produces 119 g CO2(eq)/km (with M100 consumption of 5.1 l/100 km), and the
total GHG emissions are 135 g CO2(eq)/km. If natural gas based M100 is used in the
ICE-CI vehicle of urban commuter size class (2 seats, 20 kW, see Ch. 3.3), the total
GHG emissions are reduced to 75 g CO2(eq)/km. These fuel chain GHG emissions are
72 and 40%, respectively, of the fuel chain emissions of the reference case (RFG in
ICE-SI Family car, Ch. 3.4.1) and about 104% of the fuel chain emissions of ICE-CI
vehicles using conventional city-diesel fuel. The total fuel chain emissions are increased
by 4% compared to the city-diesel use.
3.4.6 CASE 6: Electrical vehicles (electricity produced from biomass vs.
average production)
The fuel chain carbon dioxide emissions of electrical vehicles (EV) using average electricity produced in Finland (case A) and average electricity produced in Europe (EU,
rough estimate, case B) are presented in Table 45. In addition to CO2, methane and
Table 45. Fuel chain CO2 emissions of electrical vehicles (EV) using average electricity
produced in Finland (case A) and average electricity produced in Europe (EU, rough
estimate) (case B).
NiMH battery EV (e.comm)
CO2 TOTAL (g CO2km))
A.
Electric power production
A1. Finland's average power mix
A1a. Family car (5 seats, 50 kW)
A1b. Urban commuter (2 seats, 20 kW)
A2. Europe's average power mix
A2a. Family car (5 seats, 50 kW)
A2b. Urban commuter (2 seats, 20 kW)
B.
End use in vehicles
B1. Family car (5 seats, 50 kW)
B2. Urban commuter (2 seats, 20 kW)
FUEL CHAIN CO2, TOTAL (g CO2/km)
A.
FINLAND
1.
Family car (5 seats, 50 kW)
2.
Urban commuter (2 seats, 20 kW)
B.
EUROPE
1.
Family car (5 seats, 50 kW)
2.
Urban commuter (2 seats, 20 kW)
66
58
38
g CO2(eq)/km
g CO2(eq)/km
77
51
g CO2/km
g CO2/km
0
0
g CO2(eq)/km
g CO2(eq)/km
58
38
g CO2(eq)/km
g CO2(eq)/km
77
51
g CO2/km
g CO2/km
nitrous oxide emissions from electricity production should be calculated to the total
GHG emissions. For Europe, emission data for the other gases for average electricity
production were not available. As CO2 causes most the emissions from energy production, this does not affect the estimates much. For production and transportation of primary fuels for average electricity production in Finland and in Europe, a rough average
estimate of 4 kg CO2(eq)/GJ fuel and an efficiency of 30% (3.3 GJ fuel/GJ electricity)
were used. The emissions from electricity production in power plants in Finland are
about 250 g CO2(eq)/kWh (69 kg CO2(eq)/GJ), which includes emissions of N2O and
CH4.
When electricity is produced from biomass, no net carbon dioxide emissions are emitted. Only the greenhouse gas emissions from biomass fuel production, and other greenhouse gases (CH4 and N2O) from electricity production need to be considered. In this
case, the other greenhouse gases than CO2 from electricity production were not evaluated. However, the amount of non-CO2 GHGs is rather small. In Table 46, the fuel
chain GHG emissions of electrical vehicles using electricity produced from biomass in
Finland are presented.
Table 46. Fuel chain CO2 emissions of electrical vehicles (EV) using electricity produced from biomass in Finland.
NiMH battery EV (e.comm)
CO2 TOTAL (g CO2/km)
A.
Electric power production
A1a. Family car (5 seats, 50 kW)
A1b. Urban commuter (2 seats, 20 kW)
B.
End use in vehicles
B1. Family car (5 seats, 50 kW)
B2. Urban commuter (2 seats, 20 kW)
FUEL CHAIN CO2, TOTAL (g CO2/km)
1.
Family car (5 seats, 50 kW)
2.
Urban commuter (2 seats, 20 kW)
5
3
g CO2/km
g CO2/km
0
0
g CO2(eq)/km
g CO2(eq)/km
5
3
g CO2/km
g CO2/km
The CO2 emissions of average electricity production in Finland are about 58g CO2/km
for an electrical vehicle of family car size class (see Table 45). The end use does not
produce any GHG emissions, so the total CO2 emissions are 58 g CO2/km. For average
electricity production in EU the emissions would be somewhat greater (77 g CO2/km,
see Table 45). If an electrical vehicle of urban commuter size class (2 seats, 20 kW, see
Ch. 3.3) is considered, the total CO2 emissions are reduced to 38 and 51 g CO2/km for
Finland and EU, respectively. These CO2 emissions are 20–31 and 27–41% for Finland
and EU, respectively, of the fuel chain emissions of the reference case (RFG in ICE-SI
Family car, Ch. 3.4.1).
67
If the electricity were produced using only biomass, the fuel chain GHG emissions
would be reduced to 3–5 g/km (see Table 46). This is only 2–3% of the fuel chain emissions of the reference case (RFG in ICE-SI Family car, Ch. 3.4.1).
3.4.7 CASE 7: Hydrogen use in fuel cell vehicles
The use of hydrogen produced from biomass was also studied, but the results are not as
thorough as for the other cases due to uncertain/lacking data (e.g., local delivery of hydrogen), and priorities set in the project.
In Table 47, the estimated CO2 emissions of different hydrogen production chains are
listed. The end use in fuel cell vehicle does not produce any GHG emissions.
Table 47. Fuel chain CO2 emissions of fuel cell vehicles using hydrogen.
Fuel cell, H2
A. Hydrogen production & distribution
A1. Hydrogen production with average power mix
Family car (5 seats, 50 kW)
Urban commuter (2 seats, 20 kW)
A2. hydrogen production with biomass-based electricity
Family car (5 seats, 50 kW)
Urban commuter (2 seats, 20 kW)
A3. H2 prod. from natural gas
Family car (5 seats, 50 kW)
Urban commuter (2 seats, 20 kW)
A4. H2 prod. from biomass
Family car (5 seats, 50 kW)
Urban commuter (2 seats, 20 kW)
B. End use in vehicles
B1. Family car (5 seats, 50 kW)
B2. Urban commuter (2 seats, 20 kW)
FUEL CHAIN, TOTAL (g CO2/km)
A1. Hydrogen production with average power mix
Family car (5 seats, 50 kW)
Urban commuter (2 seats, 20 kW)
A2. Hydrogen production with biomass-based electricity
Family car (5 seats, 50 kW)
Urban commuter (2 seats, 20 kW)
A3. H2 prod. from natural gas
Family car (5 seats, 50 kW)
Urban commuter (2 seats, 20 kW)
A4. H2 prod. from biomass
Family car (5 seats, 50 kW)
Urban commuter (2 seats, 20 kW)
68
g CO2/km
97
53
16
9
g CO2/km
21
12
g CO2/km
9
5
g CO2(eq)/km
0
0
g CO2/km
97
53
16
9
g CO2/km
21
12
g CO2/km
9
5
When the hydrogen is produced from biomass by steam reformation (see Ch. 2.5), the
fuel chain GHG emissions are 9 and 5 g/km for the family car and the urban commuter,
respectively. These emissions are 3–5% of the fuel chain emissions of the reference case
(RFG in ICE-SI Family car, Ch. 3.4.1).
If the hydrogen were produced by electrolysis with average electricity in Finland, the
fuel chain CO2 emissions would be 97 and 53 g/km for the family car and the urban
commuter, respectively. These emissions are 28–52% of the fuel chain emissions of
reference case (RFG in ICE-SI Family car, Ch. 3.4.1).
3.4.8 Urban buses
Also city-buses were considered in this study. The summary of GHG emissions is presented in Tables 48 and 49 and graphically in Figure 15.
GHG emissions estimates for the city-buses were not carried out for as many powertrain
and fuel options as for the light-duty vehicles. The biomass-based methanol and hydrogen are the best fuels for urban buses from the GHG emissions point of view. These
fuels produce only 4–8% of the GHG emissions of the reference case (urban diesel bus
with reformulated diesel fuel).
Table 48. Summary table of fuel chain GHG emissions for different bus cases studied
(g CO2(eq)/km).
CO2 (eq)
emissions
(g/km)
Gasoline (RFG)
RFG; MTBE from biomass
Diesel (RFD)
Natural gas -based M100
Biomass-M100, Finland
Hydrogen, electrolysis,
average power prod.
Hydrogen, steam ref.,
biomass
ICE-CI, ICE-hybrid, Fuel cell, Fuel cell, Fuel cell,
urban bus, urban bus, steam rePOX,
hydrogen,
RFD/
RFD/
former, urban bus, urban bus,
M100
M100
urban bus,
RFG
H2
M100
1 559
1 537
1 593
1 350
1 622
1 363
1 420
90
75
67
1 224
113
69
Table 49. Summary table of fuel chain GHG emissions for different bus cases studied
(indexes, diesel in ”conventional” ICE-CI urban bus = 100).
CO2 (eq)
emissions
(indexes)
Gasoline (RFG)
RFG; MTBE from biomass
Diesel (RFD)
Natural gas -based M100
Biomass-M100, Finland
Hydrogen, electrolysis,
average power prod.
Hydrogen, steam ref.,
biomass
ICE-CI, ICE-hybrid, Fuel cell, Fuel cell, Fuel cell,
urban bus, urban bus, steam rePOX,
hydrogen,
RFD/
RFD/
former, urban bus, urban bus,
M100
M100
urban bus,
RFG
H2
M100
98
97
100
85
102
86
89
6
5
4
77
7
Fuel cycle GHG emissions of URBAN BUSES
Gasoline (RFG)
RFG; MTBE from biomass
Diesel (RFD)
120
nat. gas -M100
biomass-M100, Finland
Hydrogen, electrolys. av.power
Hydrogen, steam ref., biomass
INDEX (ICE-SI diesel urban bus = 100)
100
80
60
40
20
0
ICE-CI, URBAN
BUS, RFD/M100
ICE-hybrid,
URBAN BUS,
RFD/M100
Fuel cell, steam
reformer,
URBAN BUS,
M100
Fuel cell,
Fuel cell, POX,
hydrogen,
URBAN BUS,
URBAN BUS, H2
RFG
Figure 15. Fuel chain GHG emissions of urban buses (indices, urban diesel bus = 100).
70
3.4.9 Summary of fuel chain GHG emissions
The summary of the estimated fuel chain greenhouse gas (GHG) emissions for LDVs in
the different cases studied is presented in Table 50.
In Table 51, the GHG emissions are presented as indexes in proportion to reformulated
gasoline (RFG) use in conventional spark-ignited internal combustion engines (ICE-SI)
of family car (medium) size class (= 100). From these results it can be seen that the use
of methanol produced from natural gas in ICE-SI Family cars would increase the total
fuel chain GHG emissions by approximately 4% compared to present reformulated
gasoline use. In the ICE-hybrid vehicles, the use of natural gas based methanol would
reduce the GHG emissions by about 23% and 60% for the family cars and urban commuters, respectively. In the fuel cell vehicles the reduction would be 38% and 66% for
the family cars and urban commuters, respectively.
However, a much greater GHG reduction potential could be achieved, when the methanol is made from biomass. In the Finnish case, the use of the biomethanol fuel would
reduce the total fuel chain GHG emissions by 65% and 82% for the conventional ICESI family cars and urban commuters, respectively. Even greater emission reductions
could be achieved by using the biomass-based methanol in the ICE-hybrid vehicles (74–
87%) and especially, in the fuel cell vehicles, which produce only a couple per cents of
the GHG emissions from gasoline use in ICE-SI Family cars.
In the case of methanol production from eucalyptus in the Far East, the emission reduction potentials are slightly (0.5–2%) decreased compared to the Finnish case. This is due
to the GHG emissions of fertilisation (short rotation coppices) and long-range sea transportation of methanol from the Far East to Europe.
Electrical vehicles using the electricity from average production mix in Finland have
also a significant CO2 emission reduction potential (of the same order as biomass-based
methanol in ICE-hybrid vehicles). The achievable reduction in GHG emissions for the
electrical vehicles is very dependent on the way the electricity is produced, e.g., in
Europe (EU) the average emissions from electricity production are approximately 50%
higher than in Finland. If the electricity needed to power EVs could be produced completely from biomass, the total GHG emissions would drop near to zero (only non-CO2
emissions from combustion and the emissions from the biomass fuel production chain,
i.e., diesel use in HDVs, would then need to be considered).
Hydrogen use in the fuel cell vehicles would have nearly as a high GHG reduction potential as biomass-based methanol in fuel cell vehicles, if the hydrogen could be produced from biomass. A new infrastructure would be needed for the distribution of gase-
71
ous hydrogen (expensive). Distribution of liquid methanol is more easy, and smaller
changes would be required in the present gasoline distribution infrastructure (e.g. new
tanks or old ones coated to resist increased corrosion).
In diesel light-duty vehicles, the use of biomass-based methanol (M100) could have as a
high reduction potential as in fuel cell vehicles, over 95% when compared to reformulated gasoline using ICE-CI vehicles. When compared to the present diesel cars, the
GHG emission reduction potential of biomass-based M100 is fairly high (over 90%).
The emissions from urban commuters are considerably lower, in many cases 40–50%,
than those from family cars. This is due to the lower fuel consumption of the urban
commuters compared to the family cars. Increased use of such dedicated vehicles in
urban conditions could therefore lead to significant reductions in greenhouse gas emissions from transportation, for all fuels considered.
The results of Table 51 for Family cars are presented graphically in Figure 16 and for
urban commuters in Figure 17. In Figure 18, the total fuel chain GHG emissions from
Table 50 are presented separately for fuel production (including distribution) and end
use in vehicles. For the fossil fuels, 80–90% of the fuel chain GHG emissions come
from the end use.
72
Table 50. Summary table of fuel chain GHG emissions for the different cases studied (g CO2(eq)/km).
CO2 (eq)
emissions
(g/km)
Gasoline (RFG, 10% MTBE)
RFG; MTBE from biomass
Citydiesel (RFD)
MeOH from natural gas
MeOH from biomass, Finland
MeOH from biomass, Far East
Electricity, Finland aver. *
Electricity, Europe (EU) *
Electricity, biomass
Hydrogen, electrolys. av.power *
Hydrogen, steam ref., biomass
* non-CO2 GHGs not included
ICE-SI
RFG/M85
ICE-CI (diesel)
RFD/M100
FAM.
CAR
188
185
URBAN
COMM.
94
93
195
65
69
98
33
35
FAM.
CAR
URBAN
COMM.
130
135
10
13
72
75
5
7
ICE-SI/H (hybrid) ICE-CI/H (hybrid)
RFG/M85
RFD/M100
FAM.
CAR
145
143
URBAN
COMM.
74
73
145
49
51
75
25
26
FAM.
CAR
URBAN
COMM.
111
115
8
11
63
65
5
6
Fuel cell vehicle (with regeneration)
Elect. vehicle (EV)
Steam reformer
POX
Hydrogen
M100
RFG
H2
electricity from grid
FAM. URBAN FAM.
URBAN
FAM. URBAN FAMILY URBAN
CAR COMM. CAR
COMM.
CAR COMM. CAR
COMM.
129
88
127
87
117
6
8
63
3
4
58
77
5
97
9
38
51
3
53
5
73
Table 51. Summary table of fuel chain GHG emissions for the different cases studied (indexes, RFG in ICE-SI Family car = 100).
CO2 (eq)
emissions
(indexes)
Gasoline (RFG, 10% MTBE)
RFG; MTBE from biomass
Citydiesel (RFD in LDVs)
MeOH from natural gas
MeOH from biomass, Finland
MeOH from biomass, Far East
Electricity, Finland aver. *
Electricity, Europe (EU) *
Electricity, biomass
Hydrogen, electrolys. av.power *
Hydrogen, steam ref., biomass
* non-CO2 GHGs not included
ICE-SI
RFG/M85
ICE-CI (diesel)
RFD/M100
FAM.
CAR
100
99
URBAN
COMM.
50
49
104
35
37
52
18
18
FAM.
CAR
URBAN
COMM.
69
72
5
7
38
40
3
4
ICE-SI/H (hybrid) ICE-CI/H (hybrid)
RFG/M85
RFD/M100
FAM.
CAR
77
76
URBAN
COMM.
39
39
77
26
27
40
13
14
FAM.
CAR
URBAN
COMM.
59
61
4
6
33
34
2
3
Fuel cell vehicle (with regeneration)
Elect. vehicle (EV)
Steam reformer
POX
Hydrogen
M100
RFG
H2
electricity from grid
FAM. URBAN FAM.
URBAN
FAM. URBAN FAMILY URBAN
CAR COMM. CAR
COMM.
CAR COMM. CAR
COMM.
69
47
68
46
62
3
4
34
2
2
31
41
3
52
5
73
28
3
20
27
2
total fuel chain GHG emissions of FAM ILY CARS
(indexes, conventional ICE-SI using RFG = 100)
Gasoline (RFG, 10% MTBE)
RFG; MTBE from biomass
Citydiesel (RFD in LDVs)
MeOH from natural gas
MeOH from biomass, Finland
MeOH from biomass, Far East
Electricity, Finland aver.
Electricity, Europe (EU)
Electricity, biomass
Hydrogen, electrolys. av.power
Hydrogen, steam ref., biomass
120
100
74
INDEX
80
60
40
20
0
ICE-SI or ICE-CI, ICE-SI/H or ICECI/H, RFG/M85
RFG/M85 or
or M100
M100
Fuel cell, steam
reformer, M100
Fuel cell, POX,
RFG
Fuel cell,
hydrogen, H2
Electrical vehicle
(EV), electricity
from grid
Figure 16. Full fuel chain GHG emissions of different vehicles and fuels for the family car size class (indexes, RFG in ICESI Family car = 100). In cases of average electricity (in Europe) and hydrogen use, only CO2 emissions are considered.
74
total fuel chain GHG emissions of URBAN COMMUTERS
(indexes, conventional ICE-SI using RFG = 100)
60
Gasoline (RFG, 10% MTBE)
RFG; MTBE from biomass
Citydiesel (RFD in LDVs)
50
MeOH from natural gas
MeOH from biomass, Finland
MeOH from biomass, Far East
Electricity, Finland aver.
40
Electricity, Europe (EU)
INDEX
Electricity, biomass
Hydrogen, electrolys. av.power
Hydrogen, steam ref., biomass
30
75
20
10
0
ICE-SI or ICE-CI, ICE-SI/H or ICERFG/M85 or
CI/H, RFG/M85 or
M100
M100
Fuel cell, steam
reformer, M100
Fuel cell, POX,
RFG
Fuel cell,
hydrogen, H2
Electrical vehicle
(EV), electricity
from grid
Figure 17. Full fuel chain GHG emissions of different vehicles and fuels for the urban commuter size class (indexes, RFG in
CE-SI family car = 100). In cases of average electricity (in Europe) and hydrogen use, only CO2 emissions are considered.
75
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IC
g CO2(eq)/km
200
180
160
140
120
100
80
60
40
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end use
production & distribution
170
25
0
119
55
10
133
4
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41
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58
Figure 18. Full fuel chain GHG emissions of different vehicles and fuels for the family car size class divided to production &
distribution and end use in the vehicle. In cases of hydrogen use, only CO2 emissions are considered.
4. Scenarios for the use of biomethanol and
hydrogen in vehicles
In the following sub-chapters estimates of the potential to produce biomass-based
methanol and hydrogen using the concepts studied are given for Finland and globally.
Only the use of the fuels in light-duty vehicles is considered.
For Finland, the potential was calculated from estimates of the availability of forest
residue resources. Estimates of how much raw material (wood chips) would be needed
to supply the whole fleet with biomass-based methanol or hydrogen are also given. The
greenhouse gas emission reduction potentials are given for two cases: 1) The LDV vehicle fleet that would comprise totally family cars (the 2010 case) and 2) the LDV vehicle fleet that would comprise 75% of family cars and 25% would be urban commuters
(the 2020 case). The reduction in potential greenhouse gas emissions is given for the
two cases for some selected powertrains (fuel cell, hybrid and ICE-SI vehicles). The
emission reduction achievable by replacing the fossil MTBE with biomass-based MTBE
is also presented.
The global estimates are more uncertain. An estimate of how much biomass resources
would be required if all the estimated energy used by LDVs in 2010 would be met by
either biomass-based methanol or hydrogen is given. Estimates of how large land areas
would be needed if all the biomass needed for the methanol or hydrogen production
would come from new eucalyptus plantations are presented. Rough estimates of the
achievable reductions in greenhouse gas emissions are also given.
The estimates are theoretical calculations on what could be achieved by the alternative
options, if the fuels and powertrain and vehicle types would be used. Large changes in
fuels and vehicle types are not expected by 2010, because of the time lag in vehicle fleet
renewal. In chapter 4.2 estimates of the production costs of the biomass-based fuels are
given and the impact of the costs discussed.
4.1 Biomethanol use vs. biomass potentials
4.1.1 Finland
M100/M85
In 1998 the total motor gasoline consumption in Finland was 80 PJ/a and the number of
light-duty vehicles was almost 2 million. About 90% of the vehicles were gasoline
(ICE-SI) vehicles, so there were about 1.8 million ICE-SI vehicles. The consumption
77
with 15 000 km/vehicle per year would yield 2.95 MJ/km. It is estimated that there will
be about 2.5 million light-duty vehicles in Finland in 2010. 90% are assumed to be
gasoline vehicles and 10% diesel vehicles, if no alternative fuels are introduced before
that. The total motor gasoline consumption would increase only to 82 PJ/a due to estimated increased fuel efficiency (2.18 MJ/km, ICE-SI Family car with RFG (see Ch.
3.3)).
If all 2.5 million vehicles would be fuel cell vehicles of family car size class (theoretical
calculation), the total fuel consumption would be 54 PJ/a (1.44 MJ/km, see Ch. 3.3).
With biomass-based methanol this would mean 94 PJ/a of wood chips energy (methanol
yield 57.7% (LHV), see Table 3). The methanol production would require 11 Mt wood
chips, which is about 29 Mm3 (solid meters) wood chips per year. The technically available forest residue potential is, however, estimated to be only 8.6 Mm3/a (to date, Hakkila et al. 1998). The total amount of forest residues in Finland is estimated to be about
30 Mm3/a (solid meters, Hakkila et al. 1998). All forest residues cannot, however, be
collected because it would harm the nutrient balance in forests, and even more simply,
because of the economics (a maximum of 150 km transportation distance is economically feasible).
Energy use of wood chips made from forest residues in Finland was 0.5 Mm3/a in 1998
(less than 0.1 Mtoe). In the Finnish “Action plan for renewable energy sources”, the
target is to increase this use to 5 Mm3/a (0.9 Mtoe/a) in 2010 (Ministry of Trade and
Industry 1999). The technically available forest residue potential in 2010 and beyond is
estimated to be 10 Mm3/a. This means, that approximately 5 Mm3/a (16 PJ/a) forest
residues could be available for methanol production and vehicle use. This is only one
sixth of the theoretical amount that a 100% fuel cell vehicle fleet would need. The conclusion is that in 2010 maximally 17% of the total vehicle fleet (0.425 million out of
2.5 million) could be fuel cell vehicles using biomass-based methanol that is produced
in Finland. To produce this methanol (9 PJ/a), six (5.5) methanol plants (100 MW each)
would be needed. In Finland, there are about 20 kraft pulp mills, and so it would be possible to add a methanol production plant to six of them at appropriate distances from
each other (optimising fuel supply potential and costs).
The total primary energy consumption by transport in Finland was 175 PJ in 1998,
which means that about 5% (9 PJ/a) of energy needed in transportation could be produced from biomass-based methanol by using it in fuel cell vehicles of family car size
class.
In Table 52, the GHG emission reductions from the use of this amount of biomassbased methanol (9 PJ/a, 5.5 MeOH plants, 100 MW each) in different cases and vehicle
type fleets are presented. If all the methanol would be used for fuel cell vehicles of
78
family car size class, the total GHG emission reduction would be 1.2 Mt CO2(eq)/a. If
all these fuel cell vehicles would be urban commuters (city-cars with 2 seats, see Ch.
3.3), the total GHG emission reduction is 2.2 Mt CO2(eq)/a (theoretical maximum).
Table 52. Theoretical fuel chain GHG emission reductions for different vehicle fleets
(whole fleet is the same vehicle type) using biomass-based methanol (M100 or M85).
2.5
2.5
Mill. LDVs (ALL FAMILY CARS)
Mill. LDVs (not increasing over 2.5 million)
75%
25%
Family cars
Urban commuters
Theoretical
100%
Urban commuters
by 2010:
1 MeOH plant:
MeOH (M85/M100)
MeOH (M85/M100)
(9 PJ/a, 5.5 plants)
CO2(eq) reduction potential,
biomass-MeOH
Reduction potential,
MeOH from biomass
fuel cell hybrid ICE-SI
by 2010
by 2020
from which
by 2020:
1 MeOH plant:
MeOH (M85/M100)
MeOH (M85/M100)
(9 PJ/a, 5.5 plants)
CO2(eq) reduction potential,
biomass-MeOH
Reduction potential,
MeOH from biomass
Theoretical
(all urban commuters):
1 MeOH plant:
9 PJ MeOH/a, 5.5 plants
CO2(eq) reduction potential,
biomass-MeOH
Reduction potential,
MeOH from biomass
3.1
17.0
3.7
20.5
2.8
15.2
% of total number of vehicles
% of total number of vehicles
16.5
15.2
9.9
1.2
1.1
0.7
% of GHGs from ICE-SI using RFG
in 2010
Mt CO2(eq)/a
fuel cell hybrid ICE-SI
3.6
19.8
4.4
24.3
3.3
18.2
% of total number of vehicles
% of total number of vehicles
19.3
18.6
12.5
1.4
1.3
0.9
% of GHGs from ICE-SI using RFG
in 2010
Mt CO2(eq)/a
fuel cell hybrid ICE-SI
5.7
31.3
30.8
7.2
39.7
34.4
5.5
30.1
24.8
2.2
2.4
1.7
% of total number of vehicles
% of total number of vehicles
% of GHGs from ICE-SI using RFG
in 2010
Mt CO2(eq)/a
The theoretical maximum GHG emission reduction potential would be somewhat higher
(2.4 Mt CO2(eq)/a compared to 2.2 Mt CO2(eq)/a for Urban fuel cell commuters) if the
methanol (9 PJ/a) were used for M85 in hybrid vehicles of urban commuter size class
(see Table 52). This is due to the limited forest residue potential. The methanol-gasoline
79
blends would suffice for a higher number of vehicles than M100 (in fuel cells). However, the situation in 2010 (all hybrid vehicles of family car size class) would lead to a
slightly smaller reduction potential of 1.1 Mt CO2(eq)/a (compared to 1.2 Mt CO2(eq)/a
for fuel cell vehicles).
If the forest residue potential was unlimited, biomethanol use in fuel cell vehicles could
reduce Finnish GHG emissions by 6.8 Mt CO2(eq)/a out of a total of 7.0 Mt CO2(eq)/a
(RFG in ICE-SI) in 2010 (97% for family cars, see Table 51). This would increase the
number of methanol plants needed to 33.
MTBE
Another option would be to use the forest residues available to make all the methanol
needed for MTBE (10% MTBE in RFG) production from biomass and use it in conventional ICE-SI Family car. Only one methanol plant would then be needed (see Table
53), and the GHG emission reduction potential would be only 0.1 Mt CO2(eq)/a compared to conventional RFG (natural gas based methanol in MTBE) use in 2010. This
reduction is only approximately one tenth of what could be achieved by methanol use in
fuel cell or hybrid RFG vehicles (family cars).
Table 53. The methanol production of one plant for MTBE use. The MTBE suffices for
the gasoline consumption of 1.2–3 times the whole fleet (2.5 million).
MTBE production, 1 MeOH plant
if all vehicles would be of this type
(theoretical maximum)
fuel cell
hybrid
ICE-SI
RFG
RFG
RFG
MeOH production
83 440
83 440
83 440
MTBE production
231 778
231 778
231 778
RFG production.
2 317 778 2 317 778 2 317 778
Energy available
99 896
99 896
99 896
Family car
1.60
1.68
2.18
Urban commuter
1.09
0.85
1.09
Family car
62 378
59 566
45 926
Urban commuter
91 377
117 062
91 851
Average driving
15 000
15 000
15 000
distance/vehicle
Family car
4 158 564 3 971 040 3 061 705
Urban commuter
6 091 771 7 804 153 6 123 409
Family car
166
159
122
Urban commuter
244
312
245
80
t MeOH/a
t MTBE
t RFG/a
TJ/a
MJ/km
MJ/km
Mkm/a
Mkm/a
km/vehicle, a
vehicles
vehicles
% of total number of vehicles
% of total number of vehicles
Hydrogen
If the 2.5 million cars in Finland (in 2010) would be fuel cell vehicles of family car size
class (again, theoretical calculation), the total fuel consumption would be 54 PJ/a
(1.44 MJ/km, see Ch. 3.3) as mentioned before. With biomass-based hydrogen this
would mean 78 PJ/a of wood chip energy (hydrogen yield 70% (LHV), see Table 6) and
further, 9 Mt wood chips, which is about 24 Mm3 (solid meters) wood chips per year.
Again, the technically available forest residue amount is less and would suffice only for
maximally one fifth of the amount that the theoretical 100% fuel cell vehicle fleet would
need. The conclusion is that in 2010 maximally 20% of the total vehicle fleet (0.5 million out of 2.5 million) could be fuel cell vehicles using biomass-based hydrogen that is
produced in Finland. To produce this hydrogen (10.8 PJ/a), six (5.4) hydrogen plants
(100 MW each) would be needed. In Finland, as discussed earlier, there are about 20
kraft pulp mills and so it would be possible to add hydrogen production plants to six of
them with appropriate distances from each other (optimising fuel supply potential and
costs).
The total primary energy consumption by transport in Finland was 175 PJ in 1998, i.e.
about 6% (10.8 PJ/a) of energy needed in transportation could be produced from biomass-based hydrogen by using it in fuel cell vehicles of family car size class.
In Table 54, the GHG emission reductions from the use of this amount of biomassbased hydrogen (10.8 PJ/a) in different cases and vehicle type fleets are presented. If all
10.8 PJ MeOH/a would be used for fuel cell vehicles of Family car size class the total
GHG emission reduction would be 1.4 Mt CO2(eq)/a. If all fuel cell vehicles would be
Urban commuters (city-car of 2 seats, see Ch. 3.3), the total GHG emission reduction is
2.6 Mt CO2(eq)/a (theoretical maximum).
Unlimited forest residue potential would give a GHG emission reduction of
6.6 Mt CO2(eq)/a out of a total of 7.0 Mt CO2(eq)/a (RFG in ICE-SI) in 2010 (94% for
Family cars, see Table 51). This would increase the number of hydrogen plants needed
to 27.
The examinations above show that the potential for methanol or hydrogen production
from forest residues is limited in the near future in Finland. The sustainable stem wood
production in Finland is used mainly by the pulp and paper industry including energy
production. The expected growth of the pulp and paper industry, and new harvesting
techniques for forest residues, may increase the technical and economic availability of
the forest residues. There are, however, also other competing uses for this raw material.
Energy production (electricity and heat) from this biomass resource is currently seen as
more promising and economic than methanol or hydrogen production.
81
Table 54. Theoretical fuel chain GHG emission reductions for fuel cell vehicle fleet
(whole fleet is the same vehicle type) using hydrogen.
By 2010
By 2020
from which
75%
25%
2.5
2.5
Mill. LDVs (FAMILY CARS)
Mill. LDVs
2
0.5
Mill. family cars
Mill. urban commuters
Theoretical
2.5
By 2010:
1 hydrogen plant
11 PJ hydrogen/a, 5.5 plants
CO2(eq) reduction potential, biomass-H2
Fuel cell
3.7 % of total number of vehicles
20.4 % of total number of vehicles
19.3 % of GHGs from ICE-SI using RFG in
2010
1.4 Mt CO2(eq)/a
Reduction potential, H2 from biomass
By 2020:
1 hydrogen plant
11 PJ hydrogen/a, 5.5 plants
CO2(eq) reduction potential, biomass-H2
Reduction potential, H2 from biomass
Theoretical (all urban commuters):
1 hydrogen plant
11 PJ hydrogen/a, 5.5 plants
CO2(eq) reduction potential, biomass-H2
Reduction potential, H2 from biomass
Mill. urban commuters
Fuel cell
4.3 % of total number of vehicles
23.8 % of total number of vehicles
23.2 % of GHGs from ICE-SI using RFG in
2010
1.6 Mt CO2(eq)/a
Fuel cell
6.8 % of total number of vehicles
37.6 % of total number of vehicles
36.5 % of GHGs from ICE-SI using RFG in
2010
2.6 Mt CO2(eq)/a
Therefore, due to the limited forest residue potential, the best option to reduce GHG
emissions by biomass-based transportation fuels seems to be hydrogen or methanol use
in urban fuel cell commuters (2 seats, 20 kW). This would also lead up to better air
quality in urban areas.
4.1.2 Global
Globally the transportation sector (international bunkers excluded) consumed slightly
over 69 EJ, or more than 20% of the primary energy in 1997. The growth in the energy
consumption in the transportation sector has been fast, and this growth is expected to
continue. Road transportation is a major energy consumer in transportation sector, it is
estimated to account for more than 70% of transport energy use, light-duty vehicles
alone comprise about 50%. Assuming a growth of about 15% in energy consumption of
82
road transportation by 2010, the total energy use would be around 58 EJ for road transportation and around 40 EJ for light-duty vehicles.
The global potential of biomass availability for methanol or hydrogen production is
more difficult to estimate. The Finnish forest resources, annual growth of forest and
fellings, and forest residue availability, are well-known, whereas global similar estimates are much more uncertain.
International statistics on forest resources are collected and published by the Food and
Agricultural Organisation of the United Nations FAO (Finnish Statistical Yearbook on
Forestry 1999). The last global assessment of forest resources was published in 1995
(1990 resources). Some preliminary information is available on 1998 resources in industrialised countries (only boreal and temperate forests). In 1990, about one fourth of
the global land area was estimated to be forest land. The volume of growing stock was
estimated to be about 380 000 Mm3 (incl. bark). The largest forest resources are in Latin
America and the Caribbean (appr. 110 000 Mm3) and Russia (appr. 80 000 Mm3). The
forest resources in North America, Asia and Africa are also significant (more than
50 000 Mm3/area), while in Europe forest resources are less than 20 000 Mm3 and in
Oceania only about half of this.
The global figures on annual growth of the forests and fellings are not known. IPCC
(2000a) has estimated that the net terrestrial uptake of carbon has been approximately
700 mill. t CO2(eq) during the 1980s and more than 2 500 mill. t CO2(eq) in the 1990s.
The estimates are, however, very uncertain.
The above estimates on global forest resources and the annual growth of terrestrial uptake indicate that the biomass resources available could cover a large part of the global
energy demand. IPCC (2000b) gives an estimate of 2 700 EJ for annual bioenergy potential, of which however only 270 EJ could currently be available on a sustainable basis. This figure is almost the same (266.9 EJ) as given by Johansson et al. (1993) as the
estimated potential supply of biomass energy by biomass plantations. The value was
calculated using an average annual yield of 15 dry t/ha, a value typical of high-yield
plantations.
To support the future growth in bioenergy use, additional land for biomass plantations
would be needed. However, the need for new agricultural land limits the extent, to
which this option can be utilised. Leach and Johnson (1999) have made estimates on
bioenergy potentials based on FAO estimates of potentially cultivable land. Land requirement for food crop production is subtracted, assuming that the need in 2025 will be
1.5 times the 1990 figure. One-tenth of remaining land was then assumed to be dedicated to energy crops with an average annual yield of 10 dry t/ha. The estimated potential for Africa is 79 mill. ha and for Latin America 89 mill. ha.
83
A rough estimate on the land-area needed to supply the total global light-duty vehicle
fleet with methanol or hydrogen used in fuel cell vehicles in 2010 is given (theoretical
calculation). Taking into account the better efficiencies of the fuel cell vehicles the fuel
demand would be approximately 25 EJ methanol (FC STM) and 17 EJ hydrogen (direct
FC-EV drive, no regenerative braking). Assuming the Far East concept would mean that
approximately 2 500 Mill. t ds/a eucalyptus would be needed for the methanol production. About 2 800 plants would need to be built which would mean a production capacity of chemical pulp that is almost 10 times the current production. The corresponding
demand for land area for the plantations would be about 250 mill. ha assuming an annual yield of 10 dry t/ha. This area would be equal to about 7 times Finland’s or Japan’s
land area.
The amount of biomass needed would be less if hydrogen was produced, approximately
1 700 mill. t ds/a, corresponding to a land area of about 170 mill. ha (approximately five
times the area of Finland or Japan).
The associated greenhouse gas emission reduction would be in the same order for both
methanol and hydrogen, approximately 3 000 Mill. t CO2(eq)/a (current total anthropogenic emission is about 23 000 mill. t CO2(eq)/a).
The above calculations are theoretical, but they show that the entire fuel demand of
light-duty vehicles would be difficult to meet by producing methanol or hydrogen from
biomass, even if they were used in advanced vehicles. Large land areas would be
needed for the production of the raw material, and there are many competing uses for it.
The possibilities to integrate methanol and hydrogen production to pulp production are
also limited.
In more restricted use, e.g. in urban transportation, the fuels could have potential, especially as their use in clean vehicles like the fuel cell vehicles, would have also other
environmental benefits (improved air quality).
4.2 Production costs and implementation
The costs of methanol production from biomass and natural gas are compared in Table
55. Tax-free consumer prices for gasoline and diesel and an estimated value of average
electricity production cost are also presented to see the order of magnitude. However,
direct cost comparison cannot be made between present vehicle fuels and methanol,
because the tax-free consumer prices include, e.g., distribution costs and profits for interested parties and thus are not pure production costs.
84
Table 55. Summary of estimated fuel production costs (present).
Gasoline (RFG, 10% MTBE) *
Citydiesel (RFD) *
MeOH from natural gas**
MeOH from biomass, Finland
MeOH from biomass, Far East
Electricity, Finland average ***
Hydrogen, steam ref., biomass
EUR/GJ
9.8
5.7
4.7
16.4
9.6
7.0
12.3
FIM/MWh
210
123
ca. 100
351
205
150
263
*
tax-free consumer price, calculated from 6.75 FIM/l for gasoline and 4.90 FIM/l for diesel (actual
production costs are much lower, as these include also distribution costs and profits).
** current world market price of methanol
*** rough estimate, actual production cost is unknown (tax-free consumer prices are 0.3 – 0.4 FIM/kWh.
From Table 55, it is seen that methanol production in the Far East is clearly cheaper
than in Finland due to the larger size class of production facility (5-fold, see Ch. 2). The
production cost is still about two times more expensive than that of the present methanol
from natural gas production. In the Finnish case, the difference is about 3.5-fold. The
production costs of hydrogen from wood chips in Finland are in between the methanol
production costs in the Far East and Finland. This means, that it is cheaper to produce
hydrogen than methanol.
The production costs of the different vehicle types, and the fuel distribution and refuelling costs were not considered in the study.
With the production costs presented in Table 55, the rough GHG emission reduction
costs were calculated (only for production costs, fuel distribution and vehicle costs were
not considered, see Table 56). In the case of gasoline (RFG) it was assumed that the
production cost would be 80% of the tax-free consumer price (47 FIM/GJ). The costs of
reduction were obtained by comparing production costs of other fuels to this value and
dividing the difference with the potential of emission reduction (from Table 51).
For biomass-based M100 produced in Finland the emission reduction is 82 kg
CO2(eq)/GJ when used in a fuel cell vehicle of family car size class. The production of
this M100 fuel is about 51 FIM/GJ more expensive than RFG production (98–
47 FIM/GJ). Hence, the emission reduction cost (fuel production costs only taken into
account) is about 620 FIM/t CO2(eq) (104 EUR/t CO2(eq)), which is quite expensive.
Additional costs from changes in fuel distribution equipment and vehicle production
would make the option even less attractive economically.
For the Far East case, the reduction cost is reduced to about 130 FIM/t CO2(eq)
(22 EUR/t CO2(eq)). This reduction cost is comparable with some other options considered feasible in Finland. However, the cost of methanol sea transportation and costs
85
from changes in local distribution (plus additional production costs of fuel cell vehicles
compared to conventional vehicles) would eventually enhance the reduction cost.
For biomass-based hydrogen production in Finland, the reduction cost is about
360 FIM/t CO2(eq) (60 EUR/t CO2(eq)). If hydrogen would be produced in the Far East
(this case was not considered in this study), the greater biomass potential would allow a
higher production capacity and lead to reduced costs [about 90 FIM/t CO2(eq) or
15 EUR/t CO2(eq)] assuming the same difference between Finland and the Far East as
in the case of methanol production.
Table 56. Summary of estimated GHG reduction costs (based only on fuel production
costs (present), i.e. the additional costs of fuel distribution and fuel cell vehicle production are not considered).
FC, biomass-M100, Finland
MeOH, Finland
98
RFG
47
Cost difference
51
Reduction
82
Cost of reduction
616
FIM/GJ
FIM/GJ
FIM/GJ
kg/GJ
FIM/t CO2(eq)
FC, biomass-M100, the Far East
MeOH, the Far East
57 FIM/GJ
RFG
47 FIM/GJ
Cost difference
10 FIM/GJ
Reduction
82 kg/GJ
Cost of reduction
126 FIM/t CO2(eq)
FC, biomass-H2, Finland
H2, Finland
73
RFG
47
Cost difference
26
Reduction
73
Cost of reduction
361
FIM/GJ
FIM/GJ
FIM/GJ
kg/GJ
FIM/t CO2(eq)
The implementation of the methanol or hydrogen production concepts considered in this
study are technically feasible, but the high production costs are seen as an implementation barrier. To overcome this barrier in near future, either subsidies for methanol/hydrogen production or substantial environmental taxes for oil-derived fuels (or
considering Finland reductions in current fuel taxes) would have to be used. For longer
term, it could also be possible to reduce the production costs by improving efficiencies
and raw material (forest residues) logistics.
86
5. Conclusions and discussion
In this study new concepts for methanol and hydrogen production from wood-based
biomass are presented in order to assess the climate benefits that could be achieved from
the use of these fuels in advanced vehicles, with focus on fuel cell vehicles. The process
concepts chosen for a closer study integrate methanol or hydrogen production to CHP
production in an existing pulp mill. The greenhouse gas emissions for the use of the
biofuels in specified vehicle types were estimated and compared to corresponding emissions from the use of gasoline, diesel, methanol made from natural gas, hydrogen derived from electrolysis of water and those of electric vehicles. Estimates for the potential use of the biofuels are given based on estimated availability of biomass resources.
Possibilities to integrate the production of the fuels to CHP production of a pulp mill
were also assessed. Implications of the estimated production cost for the biofuels were
also discussed.
The production of methanol from biomass requires a fairly advanced gasification and
gas cleaning process to meet the requirements of the synthesis process. The hydrogen
production process is somewhat simpler. However, the evaluation of the hydrogen production processes was based on a more shallow evaluation due to priorities set in the
project. The hydrogen production process should, therefore, be studied in more detail to
assess, if some additional improvements in the process could be made.
Two methanol production concepts were selected for evaluation: methanol production
integrated to an existing pulp mill in Finland and in the Far East. Performance and costs
of corresponding hydrogen production were estimated roughly for the Finnish case. The
fast growth of wood would allow higher capacities of fuel production in the Far East
than in Europe. The capacities were selected based on the availability of the raw material at a moderate price. In the Finnish case (fuel input 100 MWth) the raw material was
forest residues (pine) and in the Far East case (500 MWth) short rotation coppices
(eucalyptus). The methanol production would be 83 400 t/a in the Finnish case and
439 400 t/a in the Far East case. The production costs in the Finnish case were estimated
at around 16 EUR/GJ methanol. In the Far East case the methanol production costs were
lower, approximately 10 EUR/GJ methanol. Recently, the world market price of methanol has been about 4.7 EUR/GJ. The scale of the plant has a considerable effect on the
fuel production costs. Currently, the largest natural gas based methanol plants have a
capacity of > 800 000 t methanol/a.
By combining the fuel, power, and heat production a high total efficiency can be
achieved. In this study, it was estimated that by integrating the methanol production to
the power plant of the pulp mill, the total efficiency of the methanol plant would be increased to 67–69% (LHV). Employing the district heat production for utilising the low-
87
grade waste heat would increase the total efficiency. Reductions of about 20% were
estimated in the methanol production costs by using the existing equipment of the pulp
mill. Further improvements in the total efficiency and consequent production cost reductions could be achieved by process optimisation (optimised gasification temperature,
minimised oxygen consumption, high carbon conversion in gasification, small hydrocarbon content in gasification gas, optimised methanol synthesis).
All the energy demand of the processes is met by energy produced by biomass. No CO2
emissions are therefore allocated to the production processes as the biomass is assumed
to be of sustainable origin. The integrated production processes do, however, consume
biomass resources and have a somewhat lower power output [although increased total
energy (power and heat) production] than a non-integrated pulp production process
would have. If these biomass resources and power were used to replace fossil energy,
the climate benefits of the process would be lowered. This is, however, not considered
in the study.
The greenhouse gas emissions from the use of biomass-based methanol and hydrogen
were estimated for some selected powertrain and vehicle types, and compared to the use
of other fuels (gasoline, methanol from natural gas, and hydrogen from electrolysis using fossil or biomass-based electricity). The total fuel chain greenhouse gas emissions
(emissions from fuel production and distribution + emissions from the use in the vehicles) are significantly lower (approximately 80–90%) for the biomass-based methanol
and hydrogen fuels than for the other alternatives. Only battery electric vehicles using
electricity produced from biomass have emissions that are as low (see Ch. 3.4.9 for
more detailed summary of different fuel chain greenhouse gas emissions). Extensive use
of battery-electric vehicles using biomass electricity would, however, require even
larger biomass resources, as the energy efficiency of electricity production is lower than
that of methanol production.
The implementation of biomass-based methanol and hydrogen as transportation fuels
has technical and economic barriers. The biomass resources are limited and the amounts
of biomass needed for substituting conventional fuels with biofuels would be large. Estimates on the availability of raw material (forest residues or eucalyptus) for the concepts studied showed that the entire fuel demand of light-duty vehicles would be difficult to meet by the concepts considered, even if the fuels were used in advanced vehicles. Large land areas would be needed for the production of the raw material, and there
are many competing uses for it. The possibilities to integrate methanol and hydrogen
production to existing pulp mills are also limited.
The greenhouse gas emission reductions that could be achieved in Finland by methanol
or hydrogen produced from forest residues, taking the limited availability of the
88
resources into account, were estimated for the years 2010–2020. The use of these fuels
was estimated to give maximally reductions of the order 10–20% compared to gasoline
use in LDVs of family car type (description in Ch 3.3). The use in methanol in fuel cell
or hybrid-ICE vehicles was estimated to give almost equal reductions (~15%), whereas
the use in ICE-SI vehicles gave smaller reductions (~10%). The use of hydrogen in fuel
cell vehicles gave a few percentage units higher emission reductions than methanol. In a
vehicle fleet with a large share of urban commuter type cars (description in Ch. 3.3)
using biomethanol or biohydrogen the emissions would be much smaller. Methanol
from biomass could also be used for MTBE production. In Finland the whole LDV
vehicle fleet could be supplied with MTBE using methanol made from forest residues.
The emission reduction achieved would, however, be much less, only one tenth of what
could be achieved by methanol use in fuel cell or hybrid vehicles.
The costs of producing wood-based methanol and hydrogen were, depending on the
concept chosen (fuel input 100–500 MWth), of the order of 2 to 4 times higher than
those of gasoline or methanol made from crude oil and natural gas. Subsidies or tax
incentives would be needed to introduce the wood-based fuels to the market.
The use of the biomass-based fuels in advanced and, especially, fuel cell vehicles, is
promising. The fuel cell vehicles will likely be introduced to the market within a few
years. The market share of these vehicles will be minor still long, partly because of the
time lag in the renewal of the vehicle fleet. The availability of sustainable hydrogen and
hydrogen carrier fuels is scare and could in the long run become the main obstacle for
the success of the fuel cell vehicles. Sustainable hydrogen production technology based
on chemical or biological processes or electrolysis utilising renewable energy, or production of hydrogen from fossil fuels combined with CO2 recovery and disposal, are not
expected to be of commercial technology until in the mid of the century, if even then.
Biomass-based methanol, or hydrogen, could therefore play a role in enhancing the introduction of the fuel cell vehicles to the market before other sustainable concepts for,
e.g., hydrogen production are developed. The foreseen growth in the transportation volume and decreasing oil resources could also increase the attractiveness of biomassbased methanol, or hydrogen, as transportation fuels in the future. Environmental benefits are seen especially in urban transportation, where the use of the fuels in fuel cell
vehicles could also improve the local air quality substantially.
This study addresses only the greenhouse gas emissions for the chosen biomass-based
methanol and hydrogen production processes and the use of the fuels in mainly light
duty vehicles. The implications of system changes (distribution, storage) needed to
introduce the fuels to the markets would also need to be analysed. The estimates of
achievable greenhouse gas emission reductions, taking the biomass resources into
account, would also need to be extended to heavy-duty vehicles. Other environmental
89
impacts and safety aspects should also be assessed. To be able to fully assess the
greenhouse impact of the introduction of the fuels and new vehicle technologies to the
market, system studies on the impact on energy and industrial (vehicles) manufacturing,
and also agricultural and forestry sectors, would be needed.
90
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94
Series title, number and
report code of publication
Published by
Vuorimiehentie 5, P.O.Box 2000, FIN-02044 VTT, Finland
Phone internat. +358 9 4561
Fax +358 9 456 4374
VTT Research Notes 2074
VTT–TIED–2074
Author(s)
Mikael Ohlström, Tuula Mäkinen, Juhani Laurikko & Riitta Pipatti
Title
New concepts for biofuels in transportation
Biomass-based methanol production and reduced emissions in advanced vehicles
Abstract
New production concepts for biomass-based methanol and hydrogen for use as transportation fuels
were evaluated. The fuel chain greenhouse gas emissions for these biofuels were estimated and
compared with corresponding emissions for gasoline and some other fuels.
Concepts with methanol or hydrogen production integrated with pulp and paper production were
studied more closely. These concepts were found to increase the total efficiency and lower the
production costs compared to stand-alone plants. However, the costs were estimated still to be 2 to
4 times higher than those of fossil transportation fuels on average.
The estimation of the fuel chain emissions included emissions from production and distribution
of the fuels to end use in selected vehicle types. The estimated total fuel chain greenhouse gas
emissions were significantly lower (approximately 80–90%) for the biomass-based methanol
and hydrogen fuels than for most of the other considered alternatives. The availability of
biomass resources for the production of biomethanol or biohydrogen and the high production
costs were estimated to limit the implementation of the process concepts and use of the fuels in
transportation. Most promising prospects for biomass-derived methanol or hydrogen were seen
as fuels for fuel cell vehicles in urban transportation.
Keywords
biomass, biofuels, wood, liquefaction, gasification, methanol, costs, emissions, greenhouse gases, engine fuels
Activity unit
VTT Energy, Energy Systems, Tekniikantie 4 C, P.O.Box 1606, FIN–02044 VTT, Finland
ISBN
Project number
951–38–5780–8 (soft back ed.)
951–38–5781–6 (URL: http://www.inf.vtt.fi/pdf/)
Date
January 2001
Language
English
Name of project
New concepts for biofuels in transportation. Biomassbased methanol production and reduced emissions in
advanced vehicles
Series title and ISSN
VTT Tiedotteita – Meddelanden – Research Notes
1235–0605 (soft back ed.)
1455–0865 (URL: http://www.inf.vtt.fi/pdf/)
N8SU00236
Pages
94 p.
Price
B
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