Polish Journal of Chemical Technology, 19, 3, 49—55,
Pol. J.10.1515/pjct-2017-0048
Chem. Tech., Vol. 19, No. 3, 2017
49
Biodiesel production from vegetable oil: Process design, evaluation and
optimization
Hamid Reza Kianimanesh1, Farzin Abbaspour-Aghdam1*, Mehrab Valizadeh Derakhshan2
1
Sahand University of Technology, Biotechnology Research Center, Faculty of Chemical Engineering, Tabriz, Iran
Amirkabir University of Technology (TehranPolytechnic), Departmentof Chemical Engineering, Tehran, Iran
*
Corresponding author: e-mail: f_abbaspour@sut.ac.ir
2
To investigate the effect of reactor performance/configuration of biodiesel production on process parameters (mass
& energy consumption, required facilities etc.), two diverse production processes (from vegetable oil) were implemented/designed using Aspen HYSYS V7.2. Two series reactors were taken into account where overall conversion
was set to be 97.7% and 70% in first and second processes respectively. Comparative analysis showed that an
increase in conversion yield caused to consumption reduction of oil, methanol, cold energy and hot energy up to
9.1%, 22%, 67.16% and 60.28% respectively; further, a number of facilities (e.g. boiler, heat exchanger, distillation
tower) were reduced. To reduce mass & energy consumption, mass/heat integration method was employed. Applying integration method showed that in the first design, methanol, cold and hot energy were decreased by 49.81%,
17.46% and 36.17% respectively; while in the second design, oil, methanol, cold and hot energy were decreased
by 9%, 60.57% 19.62% and 36.58% respectively.
Keywords: Process Design, Heat & Mass Integration, Biodiesel, Pinch Technology, Heat Exchanger Network.
INTRODUCTION
Fossil fuels as well as their derivatives have been the
greatest energy source over the recent two centuries.
Their imminent depletion as well as environmental
consequence of their overuse has motivated researchers
around the world to look for renewable, less pollutant,
cost-effective and reliable source of energy. Biological
fuel has received an attention among other renewable
energy sources e.g. energy from sun and wind energy,
taking into account both greenhouse issue and reliability.
According to International Energy Agency (IEA), in
2011, the global bioenergy use were 1.3 MBOE/D (million barrels of oil equivalent per day), which will reach
to 2.1 MBOE/D and 4.1 MBOE/D by 2020 and 2035
respectively; Furthermore in the year 2035, bioenergy
fuel will account for almost 8% of all transportation fuel
consumed in the world1; indicating global rise in implementing their bio-energy plans over the coming decades.
At least three critical goals can be attained through
governmental investment on bioenergy, including: (a)
lessening the mounting concerns towards greenhouse
gasses, (b) less relying on conventional depleting fossil
energy and (c)improving the agriculture sector in rural
areas to produce the feed for bio-energy industry. It is
to be noted that European countries (and Germany at
the top of the list)are the pioneers of bioenergy industry
today2. Significant deal of research is being carried out
throughout the world to apply different sources for bioenergy production as photocurrent generation, biodiesel
and bioethanol and bio-hydrogen production and etc3–4.
Comparison between biodiesel and conventional diesel
indicates that it has not only decreases the main greenhouse gas (CO2), by 78% over a life-cycle5, but also
can contribute to reduction of CO through combustion6.
It can be simply used directly in current diesel engines
directly and can be blended (in any proportion) with
diesel to improve fuel properties2.
The final cost of biodiesel is 1.5–3 times higher than that
of the conventional diesel7, Nevertheless, it constitutes
the main obstacle for its production in industrial scale.
Some of drawbacks are mainly high energy consumption,
low reactor efficiency, and material/energy loss at various
extraction/separation processes8.
With the aim of minimization of energy/material
consumption and reduction of facility usage, the effect
of reactor performance on processing parameters was
investigated in this paper. Therefore, in primary optimizations, the materials and streams which were used
to lose in the process, were collected and recycled back
to the process input/feed; further, to prevent energy
loss, pinch method – as one of efficient methods in
integration approach – were employed. In this method
the extra energy available in the process were partially
used to reduce the utility energy uptake. As such, using
identical material load and facilities (with different reactor efficiency), two different processes were sketched
where trans-esterification reaction under 60 and 1 atm.
carried out with overall yield of 97.7% and 70% at each.
BIODIESEL
Biodiesel is a combination of fatty acid esters which
can be used as fuel in diesel engines. The ester acid
compounds of the biodiesel increase the oxygen content
in fuel, leading to higher combustion yield and reduction
of air pollution2. It can be produced from animal fats,
waste oil and plant oils extracted from Soya, Sunflower,
Palm and Canola9.
Among various candidates mentioned above, oil from
oleaginous crops was found to be reliable, source taking
into account the quantity, consistency and continuity of
the flow which should be fed into a biodiesel production
plant10.
Apart from the reliability of the source in question,
Fatty Acids (FA) from oleaginous crops, though, cannot
be used directly in engines due to its low volatility and
high viscosity since it may lead to piston knocking, sedimentation, cocking and other technical troubles11–12.
To tackle this, researchers have Unauthenticated
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solutions e.g. trans-esterification which increases the
volatility and decreases viscosity index maintaining the
heating value of FA13–14.
Trans-esterification (Eq. 1) is the reaction of Alcohol
with Tri-Glyceride (TG) producing Glycerin15. Together
with TG, Free Fatty Acid (FFA) can be found in animal
and plant oils. If the FFA content would be higher than
1%, it should be removed or converted to biodiesel
(Eq. 2)16–17.
Application of catalyst is of key importance in Eq. 1
and 2 due to the nature of the trans-esterification reactions and low solubility of alcohols in FA, and more
importantly, low reaction rate, using catalysis has been
proposed10 e.g. acid, alkali and enzyme catalysts. For
trans-esterification of FA obtained from oleaginous crops,
homogeneous alkali catalysts are being conventionally
used in batch and continuous processes18–19, Alkali catalysts are preferred for biodiesel production because it is
faster than acid catalyzed trans-esterification reaction20.
However, enzymatic catalysts have not been proved to
be appropriate choice due to insufficient reaction rate21.
(1)
(2)
The produced biodiesel should also possess a number
of standards which has been clearly elaborated in ASTM
6751-02 along with their testing methods10.
Production process
Production of biodiesel can be carried out through
both batch and continuous procedures. In batch process
(Fig. 1) the reactor stirrer operates for 20 min to more
than an hour as residence time starting from a vigorous
rate down to zero to provide an initial bi-phasic separation
of glycerin (higher density) to obtain the final conversion
of 85–94%. To further increase the conversion (up to
95%), a two-step series reactor was followed at which
glycerin was removed between two stages as can be seen
in Figure 1.To separate produced esters and glycerin,
a settler or centrifuge can be employed; furthermore, the
remaining alcohol in both streams can also be removed
by Flash evaporation. Finally, to remove the remaining
impurities e.g. salts, catalyst and alcohol, the obtained
biodiesel and glycerin were rinsed with water andacid14, 22.
One of the common modifications in batch production
is the application of a series of Completely Stirred Tank
Reactors (CSTR) to improve heat transfer and production yield. As can be seen in Figure 2, the CSTR series
can also be replaced by a Plug Flow Reactor (PFR) to
increase conversion fraction as well as total processing
time which drops to 6–10 minutes only23. The choice
of alternative, however, depends on potential technical
Figure 1. Batch process in biodiesel production
Figure 2. Continuous process in biodiesel production
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51
troubles, material handling’s manner as well as cost/
benefit balance.
obtained glycerin may also be used as feed in various
industries including food, cosmetics, lubricant etc32.
Separation of ester and glycerin
The separation of ester and glycerin carries out after
the production of biodiesel in the reactor (chain) based
on the density difference among ester (light phase) and
glycerin (heavy phase) in centrifuge, decanter or hydro-cyclone. The alcohol content of reactor products (mainly
methanol) is the key parameter in mutual miscibility of
the two phases24.
PROCESS DESIGN
Alcohol separation
Alcohol separation contributes the whole process to
be more cost-effective and environmentally-friendly
since it enters to the reactor in extra proportions and is
mainly volatile, flammable and harmful. Moreover, the
separation should be carried out prior to ester-glycerol
separation, since as has been noted earlier, alcohol
content prevents the binary phase separation of ester-glycerol due mainly to practical interaction with water25.
Biodiesel treatment
Separation and purification of the produced biodiesel
is of critical importance in overall economy of biodiesel
production since the cost associated with this steps mounts to 60–80% of the total processing cost; furthermore,
it may cause a number of serious subsequent technical
difficulties when using e.g. filter plugging, higher soot
agglomeration, oil adhesion, oil coagulation, engine
knocking and failure26.
Glycerin treatment
Glycerin is considered to be the most important by-product of the biodiesel production process with its
global consumption quantity mounting to 600 Ktonnes
per year being used mainly for cosmetics (almost 28%)
and medical purposes27. The final price, however, dropped
dramatically to 7.5 US$/ton from 110 US$/ton between
2004 and 2011 due to significant increase in global biodiesel production25.
Employing thermo-chemical and biological methods, it can
be converted to highly value-added products e.g. propylene
glycol, propanoic acid, acrylic acid, propanol, i-propanol and
allylalcohol28–29. Using Fisher-Trops method in presence of
catalyst, the glycerine may be converted to fuel and hydrogen
over relatively low temperatures i.e. 225–300oC29–30.
The separated glycerin includes mainly catalyst, sapon
and ester along with negligible quantities of phosphate,
sulfur, protein, aldehyde, ketone and dissoluble inorganic
compounds. Vacuum distillation as well as physic-chemical
techniques can be employed for glycerin separation31. The
HYSYS is a software for steady-state and dynamic
process simulation created by Hyprotech as an interactive and flexible process modeling software22, 31. The
simulation was carried out using Aspen HYSYS V7.2
employing Triolein (as TG), Oleic acid (as FFA), and
m-Oleate as biodiesel as has already been used in previous communications as model representatives22, 31, 33. To
avoid side-stream reactions as well as trans-esterification,
the FFA content was taken to be 0.05% – mass ratio34.
Feed stream was taken as product of NaOH-catalyzed
bi-reactor system operating at 60oC and 1atm35–37 with
the overall conversion of 97.7%, using two series reactors
has already been investigated in previous researches38–39.
Taking into account the low cost, accessibility and
handling considerations, methanol was employed in this
investigation as the model-type alcohol, since it may not
cause difference in chemical structure of final obtained
biodiesel39–40.
In Eq. 1, the TG:Alcohol ratio is 1:3, though it was
taken in extra 1:6 for appropriate reactor performance in
practice41–42. The design was mainly intended to produce
20 m3h–1 biodiesel with mass concentration of 99.65%.
As exchanger pressure loss is about 50 kpa, the increase
of pressure in pumps were taken in a level so that the
overall pressure would remain almost at 1 atm. all along
the process since higher pressure may cause dramatic
effects on reactions and costs. NRTL was taken as the
governing Equation of State (EOS) for the process, while
for decanters; SRK was used31, 43–44.
As has been showed in Figure 3, feed-streams reacts
in Reac. 1 and the downstream lines flows to Sep. 1
(Separator 1) to separate un-reacted oils as well as the
extra methanol. The separator operates at 25oC (1 atm)
and the separation carries out in a proportion at which
the outlet (Reac. 2 feed) possesses of methanol: oil ratio
of higher than (or equal to) 6:1.
Reac. 2 products including glycerin, methanol, biodiesel
and oil were flown to Sep. 2 (Separator 2) (25oC) to
separate ester (light) and glycerin (heavy). Light phase
(ester) was directed to a recycled distillation column
(Dist. 1) with R = 1.5 and 6 trays to obtain extra-pure
methanol (100%) from biodiesel. Biodiesel-containing
flow then entered to Sep. 3 (Separator 3) to improve
purity and remove remaining catalysts via HCl-NaOH
neutralization reaction. HCl and catalyst are fed with
identical molar flow and reacts with 95% conversion
fraction to give 99.65% ultra-pure biodiesel (Table 1).
Table 1. Inlet/Outlet material inbiodiesel production process
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Pol. J. Chem. Tech., Vol. 19, No. 3, 2017
in boiling points. The obtained methanol recycled back
to the beginning of process as a feed; while glycerin was
sent out to downstream as by-product.
Finally, the cold energy (sum of cooler and condenser
energies) and the hot energy (sum of heater and boiler
energies) required for the process were calculated to be
6194 kw and 6884 kw respectively.
HEAT INTEGRATION
Figure 3. PFD of biodiesel production from vegetable oil
Effluents from Sep. 1 and Sep. 2 having large quantities of methanol and glycerin were directed to second
distillation tower (Dist. 2) with 5-tray and R = 1.5 to
yield pure methanol and glycerin with 100% and 99.54%
purity respectively, considering their significant difference
Reducing the processing costs is one of the major
challenges for chemical engineers today; which mainly
deals with utility costs. Energy consumption can be
balanced partially using heat exchangers where energy
exchanges between the cold and hot streams. Optimization as well as integration methods based generally on
thermodynamic and mathematic approaches. Mathematic
methods solve modeling problems e.g. Mixed Integer
Non-Linear Programming (MINLP) and Mixed Integer
Linear Programming (MILP) equations through classical
or stochastic methods44.
Thermodynamic methods e.g. Pinch Technology based
on thermo-kinetic principals and exergy loss reduction45.
Pinch technology was first introduced by Linhoffet al.
in 1978 to the optimization of heat exchanger networks
and lodged pinch point as the critical point of energy
consumption46.
The method was used here to design exchanger network to reduce energy consumption and loss. Energy
consumption reduction, number of used exchangers, required effective area etc., can be assigned as the scope of
pinch approach as the first step in pinch design. Energy
consumption was taken as the basis of optimization in
this study; thereafter, source and demand streams (which
can be defined as emission and receiving of energy respectively) were determined. Table 2 demonstrates the
thermal characteristics of all streams including source and
demand, regardless of the outlet streams like glycerol
line. HR-1, HR-2, HD-1 and HD-2 represent cooling
water leaving reactors and condensers respectively which
flew subsequently to utility to drop water temperature
to 25. Cp is also indicating heat capacity of each line
which can be calculated using Eq. 3:
Cp = (Cpin + Cpout) ∙ m∙/2
(3)
Where m∙ is the flux and Cpin/Cpout are the heat capacity
of inlet/outlet streams. Minimum approach temperature
(ΔTmin) was also taken as 10 in the following calculations.
Table 2. Source and demand streams and their heat characteristics
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To calculate interval temperature as the next step, the
inlet and outlet temperatures of hot flow must be diffracted from the half of minimum approach temperature of
exchangers; and the inlet and outlet cold temperatures
should be summed with the half of minimum of approach
temperature of exchangers (Eq. 4 and Eq. 5). Interval
enthalpy can also be calculated using Eq. 6.
Hot Interval Temperature = Hot Tem. – ∆Tmin
(4)
Cold Interval Temperature = Cold Tem. +∆Tmin (5)
∆Hinterrval = ∆Tinterval[CPCold – CPHot]
(6)
According to Table 3, the required hot and cold energy
for the network were found to be zero and 5988.4 kw
respectively; where the number “zero” indicates that the
source stream is able of providing all energy required by
demand stream, whereas 5988.4 kw shows that a make-up energy with this magnitude should be transferred
from utility to process in furtherance of the energy given by source stream to the demand. Moreover, as can
be seen, there is no pinch temperature among interval
temperatures confirming of no limitation for energy
transfer between streams, according to pinch principals.
Care should be taken that the exchanger approach tem-
53
perature should not be less than the minimum selected
approach temperature.
According to Table 2, since the considered source streams were able of providing required network energy, the
energy from the rebuilders heat source were not taken
into account; additionally, utilization of energy from
source stream possessing “300oC and 1 MPa” merely
to warm other streams to the maximum of 60oC is not
cost-effective and it should be saved for essential cases
e.g. boilers. Taking all Pinch principals and processing
issues into consideration, the plant demonstrated in
Figure 4 was plotted and re-characterized.
Applying the new system (Fig. 4) in the process, cold
and hot energy reduced to 5991.4 kw and 5273.6 kw
respectively at which the hot energy is consumed merely for heating the distillation reboilers. From Table 4
and Figure 4, HEX-8 can be used as energy source for
the second distillation tower’s reboilers which result in
14.68% reduction of cold energy and 16.67% reduction
in hot energy consumption. Table 5 provides a comparative report on the effect caused by applying the
integration method.
To investigate the effect of conversion on process,
similar 20 m3 h–1 production unit was designed using
Table 3. Cold and Hot utility calculation of exchanger network
Figure 4. Heat exchanger network in the biodiesel productionprocess
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Pol. J. Chem. Tech., Vol. 19, No. 3, 2017
Table 4. Heat characteristics of distillation tower reboilers
Table 5. Obtained results from first and second results
same facilities and materials. In the new design, however,
two series reactors (X = 70%) were employed. In these
conditions, the output biodiesel concentration (mass
fraction) in Sep. 3 is 90.8% which was sent to another
distillation tower with 5 trays and recycle flow ratio 1.5
directly to further increase biodiesel concentration.
The upstream line on top of this tower includes
biodiesel with appropriate purity, whereas downstream
contains a great deal of triolein because more than 30%
of the feed remains un-reacted. Therefore purification
reactors for triolein treatment were used as has been
used in the earlier design. The downstream line for
increasing in purity and recycle to the feed stream sent
to separator at 25oC; this operation resulted in triolein
with 99.51% mass concentration. Hence, in this new
process, a distillation tower, a heat exchanger, a pump
and another separator were added after Sep. 3.
In this design, to reduce energy consumption, exchanger networks have been designed applying pinch method
with the minimum approach temperature of 10oC; the
results were shown in Table 5.
CONCLUSION
Application of recycle stream and mass integration
has reduced methanol consumption up to 49.81% and
60.57% in first and second design respectively. In the
second design, since there is still a significant quantity
of un-reacted oil, it can be recycled back into feed
and reduce the oil consumption up to 9%. Cold and
Hot energies were also reduced 17.46% and 36.17%
respectively in first and 19.6% and 36.6% in second
design respectively. The number/capacity of used facilities increased in some cases as a result of application
of integration method; this item can be also optimized
depending on relative price of feed, used facilities or
other technical considerations.
From the results, it can be deduced that the increase
of reactor conversion from 70% to 97.7%, caused a significant reduction in consumed oil (9.1%), methanol
(22%), cold energy (67%) and hot energy (60.3%); in
addition to reduction of a number of used facilities e.g.
distillation tower and exchangers, were reduced.
LITERATURE CITED
1. Gadonneix, P., de Castro, F.B., de Medeiros, N.F., Drouin,
R., Jain, C., Kim, Y.D., Ferioli, J., Nadeau, M.J., Sambo, A.
& Teyssen, J. (2010). Biofuels: Policies, Standards and Technologies.
2. Gutiérrez, L.F., Sánchez, Ó.J. & Cardona, C.A. (2009).
Process integration possibilities for biodiesel production from
palm oil using ethanol obtained from lignocellulosic residues
of oil palm industry. Biores. Technol. 100(3), 1227–1237. DOI:
10.1016/j.biortech.2008.09.001.
3. Mohammadpour, R., Janfaza, S. & Abbaspour-Aghdam,
F. (2014). Light harvesting and photocurrent generation by
nanostructured photoelectrodes sensitized with a photosynthetic
pigment: A new application for microalgae. Biores. Technol.
163, 1–5. DOI: 10.1016/j.biortech.2014.04.003.
4. Valizadeh Derakhshan, M., Nasernejad, B., Abbaspour-Aghdam, F. & Hamidi, M. (2015). Oil extraction from algae:
A comparative approach. Biotechnol. Appl. Bioc. 62(3),
375–382. DOI: 10.1002/bab.1270.
5. Tyson, K.S. (2009). Biodiesel Handling and Use Guidelines (3rd ed.). Borough, USA: DIANE Publishing Company.
6. Schumacher, L.G. 1995. Biodiesel Emissions Data From
Series 60 DDC Engines. in: Bus Operations and Technology
Conference. Reno, Nevada.
7. Demirbas, A. (2009). Progress and recent trends in biodiesel fuels. Energy Conv. Manage. 50(1), 14–34. DOI: 10.1016/j.
enconman.2008.09.001.
8. Agarwal, M., Singh, K. & Chaurasia, S. (2012). Simulation
and sensitivity analysis for biodiesel production in a reactive
distillation column. Pol. J. Chem. Technol. 14(3), 59–65. DOI:
10.2478/v10026-012-0085-2.
9. Hoekman, S.K., Broch, A., Robbins, C., Ceniceros, E.
& Natarajan, M. (2012). Review of biodiesel composition,
properties, and specifications. Ren Sust. Energy Rev. 16(1),
143–169. DOI: 10.1016/j.rser.2011.07.143.
10. Rutz, D. & Janssen, R. 2007. Biofuel technology handbook, Munich, Germany, WIP Renewable Energies.
11. Perkins, L.A., Peterson, C.L. & Auld, D.L. 1991. Durability
Testing of Transesterified Winter Rape Oil (Brassica Napus L.)
as Fuel in Small Bore, Multi-cylinder, DI, CI Engines. Society
of Automotive Engineers.
12. Pestes, M. & Stanislao, J. (1984). Piston Ring Deposits
When Using Vegetable Oil as a Fuel. J. Test Eval. 12(2), 24–32.
DOI: 10.1520/JTE10699J.
13. Canakci, M. & Van Gerpen, J. (1999). Biodiesel production via acid catalysis. T ASAE 42(5), 1203–1210. DOI:
10.13031/2013.13285.
14. Gerpen, J.V. (2005). Biodiesel processing and production. Fuel Process Technol. 86(10), 1097–1107. DOI: 10.1016/j.
fuproc.2004.11.005.
15. Kusy, P.F. (1982). Transesterification of vegetable oils for
fuels. Am. Soc. Agric. Enginee. (4–82), 127–137.
16. Balat, M. & Balat, H. (2010). Progress in biodiesel
processing. Appl. Energ. 87(6), 1815–1835. DOI:10.1016/j.
Unauthenticated
apenergy.2010.01.012.
Download Date | 3/22/18 1:40 PM
Pol. J. Chem. Tech., Vol. 19, No. 3, 2017
17. Cho, H.J., Kim, S.H., Hong, S.W. & Yeo, Y.K. (2012).
A single step non-catalytic esterification of palm fatty acid
distillate (PFAD) for biodiesel production. Fuel 93(0), 373–380.
DOI: 10.1016/j.fuel.2011.08.063.
18. Kiss, A.A. & Bildea, C.S. (2012). A review of biodiesel
production by integrated reactive separation technologies. J.
Chem. Technol. Biot. 87(7), 861–879. DOI: 10.1002/jctb.3785.
19. Helwani, Z., Othman, M.R., Aziz, N., Kim, J. & Fernando,
W.J.N. (2009). Solid heterogeneous catalysts for transesterification of triglycerides with methanol: A review. Appl. Catal
A-Gen. 363(1–2), 1–10. DOI: 10.1016/j.apcata.2009.05.021.
20. Dawodu, F.A., Ayodele, O.O., Xin, J. & Zhang, S. (2014).
Application of solid acid catalyst derived from low value biomass for a cheaper biodiesel production. J. Chem. Technol.
Biot. 89(12), 1898–1909. DOI: 10.1002/jctb.4274.
21. Ma, F. & Hanna, M.A. (1999). Biodiesel production:
a review. Biores. Technol. 70(1), 1–15. DOI: 10.1016/S09608524(99)00025-5.
22. Gomez-Castro, F.I., Rico-Ramirez, V., Segovia-Hernandez, J.G., Hernandez-Castro, S. & El-Halwagi, M.M. (2013).
Simulation study on biodiesel production by reactive distillation
with methanol at high pressure and temperature: Impact on
costs and pollutant emissions. Comput. Chem. Eng. 52(0),
204–215. DOI: 10.1016/j.compchemeng.2013.01.007.
23. Portha, J.F., Allain, F., Coupard, V., Dandeu, A., Girot,
E., Schaer, E. & Falk, L. (2012). Simulation and kinetic study
of transesterification of triolein to biodiesel using modular
reactors. Chem. Eng. J. 207–208(0), 285–298. DOI: 10.1016/j.
cej.2012.06.106.
24. Bondioli, P. (2005). Overview from oil seeds to industrial
products: Present and future oleochemistry. J. Synth. Lubric.
21(4), 331–343. DOI: 10.1002/jsl.3000210406.
25. Yazdani, S.S. & Gonzalez, R. (2007). Anaerobic fermentation of glycerol: a path to economic viability for the biofuels
industry. Curr. Opin Biotech. 18(3), 213–219. DOI: 10.1016/j.
copbio.2007.05.002.
26. Johnson, D.T. & Taconi, K.A. (2007). The glycerin glut:
Options for the value-added conversion of crude glycerol resulting from biodiesel production. Environ Prog. 26(4), 338–348.
DOI: 10.1002/ep.10225.
27. Veillette, M., Chamoumi, M., Nikiema, J., Faucheux, N. &
Heitz, M. (2012). Production of Biodiesel from Microalgae. In:
Z. Nawaz, S. Naveed (Eds.), Adv. Chem. Enginee. (245–265).
Karachi, Pakistan: InTech.
28. Soares, R.R., Simonetti, D.A. & Dumesic, J.A. (2006).
Glycerol as a Source for Fuels and Chemicals by Low-Temperature Catalytic Processing. Angew Chem. Int Edit. 45(24),
3982–3985. DOI: 10.1002/anie.200600212.
29. Vaidya, P.D. & Rodrigues, A.E. (2009). Glycerol Reforming for Hydrogen Production: A Review. Chem. Eng. Technol.
32(10), 1463–1469. DOI: 10.1002/ceat.200900120.
30. Levy, M. (2013). Simulation of Biodiesel Production
Using Reactive Distillation (RD). Bachelor of Science degree
Dissertation, Department of Chemical Engineering, University
of Florida. Gainesville, Florida, United States.
31. García, M., Gonzalo, A., Sánchez, J.L., Arauzo, J. &
Peña, J.Á. (2010). Prediction of normalized biodiesel properties
by simulation of multiple feedstock blends. Biores. Technol.
101(12), 4431–4439. DOI: 10.1016/j.biortech.2010.01.111.
32. Galadima, A. & Muraza, O. (2014). Biodiesel production
from algae by using heterogeneous catalysts: A critical review.
Energy 78(0), 72–83. DOI: 10.1016/j.energy.2014.06.018.
33. Freedman, B., Pryde, E.H. & Mounts, T.L. (1984). Variables affecting the yields of fatty esters from transesterified
vegetable oils. J. Am. Oil Chem. Soc. 61(10), 1638–1643. DOI:
10.1007/bf02541649.
34. West, A.H., Posarac, D. & Ellis, N. (2008). Assessment
of four biodiesel production processes using HYSYS.Plant.
Biores.Technol. 99(14), 6587–6601. DOI: 10.1016/j.biortech.2007.11.046.
55
35. Pokoo-Aikins, G., Nadim, A., El-Halwagi, M. & Mahalec,
V. (2010). Design and analysis of biodiesel production from
algae grown through carbon sequestration. Clean Technol.
Envir. 12(3), 239–254. DOI: 10.1007/s10098-009-0215-6.
36. Samuel, O., Waheed, M., Bolaji, B. & Dairo, O. (2014).
Synthesis of Biodiesel from Nigerian Waste Restaurant Cooking
Oil: Effect of KOH Concentration on Yield. Global J. Sci.
Enginee. Technol. (15), 1–8 .
37. Wong, Y. & Devi, S. (2014). Biodiesel Production from
used Cooking Oil. Orient. J. Chem. 30(2), 521–528. DOI:
10.13005/ojc/300216.
38. Slinn, M. & Kendall, K. (2009). Developing the reaction kinetics for a biodiesel reactor. Biores. Technol. 100(7),
2324–2327. DOI: 10.1016/j.biortech.2008.08.044.
39. Ye, J., Tu, S. & Sha, Y. (2010). Investigation to biodiesel production by the two-step homogeneous base-catalyzed
transesterification. Biores. Technol. 101(19), 7368–7374. DOI:
10.1016/j.biortech.2010.03.148.
40. Chisti, Y. (2007). Biodiesel from microalgae. Biotech.
Adv. 25(3), 294–306. DOI :10.1016/j.biotechadv.2007.02.001.
41. Berrios, M. & Skelton, R.L. (2008). Comparison of purification methods for biodiesel. Chem. Eng. J. 144(3), 459–465.
DOI: 10.1016/j.cej.2008.07.019.
42. Romero, R., Natividad, R. & Martínez, S.L. (2011).
Biodiesel production by using heterogeneous catalysts. In: M.
Manzanera (Eds.), Alternative Fuel, 3–20. Rijeka, Croatia:
InTech.
43. Renner, G. & Ekárt, A. (2003). Genetic algorithms in
computer aided design. Comp. Aid. Design. 35(8), 709–726.
DOI: 10.1016/S0010-4485(03)00003-4.
44. Sánchez, E., Ojeda, K., El-Halwagi, M. & Kafarov, V.
(2011). Biodiesel from microalgae oil production in two sequential esterification/transesterification reactors: Pinch analysis
of heat integration. Chem. Eng. J. 176–177(0), 211–216. DOI:
10.1016/j.cej.2011.07.001.
45. Zhelev, T.K. & Ridolfi, R. (2006). Energy recovery and
environmental concerns addressed through emergy–pinch
analysis. Energy 31(13), 2486–2498. DOI: 10.1016/j.energy.2005.10.021.
46. Kemp, I.C. (2011). Pinch Analysis and Process Integration:
A User Guide on Process Integration for the Efficient Use
of Energy (2nd ed.). Oxford, UK: Butterworth-Heinemann.
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