The document summarizes a student project comparing biodiesel production using ethanol versus methanol. The project goals were to model and simulate a biodiesel production process in SuperPro and evaluate it from biological, structural, mechanical, and sustainability perspectives. The design options selected were transesterification of soybean oil using potassium hydroxide as the catalyst and either methanol or ethanol as the alcohol. Mass and energy balances were performed. The methanol design included two reactors while the ethanol design required three reactors and additional unit operations. Both designs were evaluated economically and environmentally.

1. Evaluation of
Biodiesel
Production:
Model Comparison
between Ethanol and
Methanol
By: Natalie Dell, Shelby Green, &
Carrington Moore
April 23rd, 2019
BE 4380

2. Recognition & Definition of Problem
& Need:
● Global warming and environmental degradation
● Fossil fuel consumption is causing global issues
○ Fossil fuel contribute to 80% of the world’s energy needs
● Daily mean value of CO2 in atmosphere
○ May 9th, 2015 → recorded at 400 ppm
○ April 14th, 2019 → recorded at 414.56 ppm.
● Scientific models warn CO2 concentration cannot exceed 450 ppm
○ Alter precipitation patterns, melt glaciers, increase sea-levels, and cause
extreme weather events
● Renewable, nontoxic, form of energy is needed to decrease the daily mean value
of CO2 in the atmosphere
● Biodiesel potential alternative to petroleum based fuels

3. Goals of Project
● Biological
○ Base catalysts transesterification of a vegetable oil differences
evaluated using methanol and ethanol
● Structural
○ The structure of this biodiesel plant will be simulated in SuperPro
including an additional sustainability aspect as well as an additional
product to decrease input costs in the production process.
● Mechanical
○ Effective use of unit operations to design a low polluting plant that
utilizes fresh or waste vegetable oils as feedstocks for the
production of biodiesel

4. Constraints and Considerations
● Safety
○ Methanol is extremely toxic and should be
handled with care
● Ethical
○ Controversy of food versus fuel
● Ecological
○ Converting land for crop use
○ Excess KCl can be sold for use in fertilizer
○ Recycling of excess alcohol
○ Glycerol coproduct
● Ultimate Use
○ Reduce carbon emissions
○ Alternative fuel source
● Skills
○ Understanding of SuperPro
○ How to model the production of biodiesel using a
soybean feedstock
○ Kinetics behind the biodiesel process
● Budgetary and Space
○ No materials needed, but production process
designed must be economically feasible
○ No use of lab for a reactor setup
● Logistics
○ Machine operators to monitor reactor
○ Unit operations cannot run in parallel
● Time
○ Allotted time was about 7 weeks

5. Questions
● User - Consumer
○ How much does the biodiesel cost compared to petroleum diesel?
○ Why does the alcohol used for production of fuel matter?
○ What effect does biodiesel have on my engine?
● Client - Producer
○ What makes your group creditable to plan this design?
○ What does a biodiesel plant cost and what is the payback time investment?
○ Which process - ethanol or methanol - will be the best investment?
● Designer - Bioprocess Engineer
○ What reactants and unit operations will provide the necessary yield?
○ What is the projected budget and timeframe for this design?
○ Who are the intended users of the system?

6. Governing Equations Based on Literature
Figure 1. Three step general reaction governing
equation of transesterification forming Fatty
Acid Alcohol Ethers (FAAE) [Musa, 2014]
Figure 2. Equation for centrifuge (Harrison et. al. 2015)

7. Design Options Based on Literature
● For production
● For sustainability measure
● For unit operations
● To increase yields
● To increase revenue
● To decrease input costs
transesterification, thermal cracking,
microemulsion
less toxic chemicals, recycling alcohol, recovery
byproducts
amount and type
feedstock, alcohol, catalyst types, temperature,
molar ratios of excess alcohol to oil
Recovering Glycerol and KCl, and their
purification processes
recycling alcohol, recovering glycerol and soap
for revenue

8. Selection of Design Options Based On
Literature
● Transesterification
● Recycling alcohol
● Soybean oil
● Catalyst
most common biodiesel production process
easy cost effective way to to decrease input costs
and increase sustainability measures
soy-based biodiesel reduces CO2 by 78%, one of
most common feedstocks made in the US, easier
to model in SuperPro than waste cooking oil,
waste cooking oil also typically has a high
percentage of soy-based oil
KOH can be used with both methanol and
ethanol, produces KCl (a good byproduct to sell) [Martin, 2016]

9. Selection of Design Options Based On
Literature
● Alcohol
● Crude
● Molar ratios
● Unit operations
Methanol has high yields while ethanol is
less toxic
Glycerol and KCl are more cost effective to
sell crude rather than including a
purification processes for both
Methanol was evaluated at a 3:1 and
ethanol was evaluated at 9:1, based on
literature
Ethanol requires additional reactor in
series to have >95% oil to biodiesel
conversion, 2 distillation columns and 2
centrifuges required for proper separation
percentages
[Hassan, 2013]

10. Synthesized Design Using Methanol

11. Synthesized Design Using Ethanol

12. Mass Balance Equations
Mass balance equations were calculated based on the stoichiometry and efficiency of reactor:
● Methanol Reactors
○ Reactor 1: 3 MeOH + 1 Soybean Oil → 3 BioDiesel + 1 Glycerol
○ Reactor 2: 36 HCl + 56.11 KOH → 74 KCl + 18.02 H2O
● Ethanol Reactors
○ Reactor 1&2: 9 EtOH + 1 Soybean Oil → 4 BioDiesel + 1 Glycerol
○ Reactor 3: 36 HCL + 56.11 KOH → 74 KCl + 18.02 H2O
Centrifuges
● The tubular bowl centrifuge equation was used with the efficiency of the decanter in SuperPro to
calculate the theoretical volumetric flow rate
Distiller Columns
● Beyond the scope of this class

13. Life Cycle Assessment: Cradle to Grave
[Sheehan, 1998]

14. Life Cycle Analysis Comparisons
[Nakani, 2012]

15. Economical Evaluation - Budget
Executive Summary - Methanol Executive Summary - Ethanol
● The payback was expected to be within 5~6 years for both processes
● Ethanol process was more expensive, but the payback was not that much longer
● Prices for soybean oil, ethanol, and methanol were pre-sets in superpro
● The cost of labor was not included, but could have caused an increase in operating cost
● Selling of byproducts (KCl and Glycerol) added additional revenue

16. Ecological Evaluation - Sustainable
Measures
● Decrease in emissions (CO2, SO2, CO, and HC)
○ Soy-based biodiesel reduces CO2 by 78%
○ CO and HC emissions are also reduced because the
oxygen in the ester compounds in biodiesel promotes
clean burning
○ Decrease of SO2 in atmosphere decreases acid rain
occurrences
● Decrease in waste due to recycling and recovery of
reactants and byproducts
○ Excess alcohol recycled by centrifuge followed by a
distillation column after the transesterification process
○ Glycerol and KCl recovered by a centrifuge followed
by a distillation column after the Refinery process
[Koltermann, 2001]

17. Conclusion
● User - Consumer
○ The price our biodiesel is 6.66 $/gal which is about twice the current average price of
diesel which is 3.15 $/gal
○ Methanol is more toxic than ethanol and typically is produced from fossil fuels
○ Biodiesel is cleaner for engine than regular diesel; it will clean out residue and burn
cleaner
■ Only concerns are rubber hoses and fuel filter (clean twice)
● Client - Producer
○ All team members have built SuperPro models, produced lab scale biodiesel, toured
bioprocessing plant, & taken Bioprocessing (BE 4380)
○ Methanol plant is $16 million, Ethanol plant $24 million while payback is a between 5 & 6
for both alcohols
○ Ethanol because not a large difference in payback and increased future sustainability
● Designer - Bioprocess Engineer
○ Bio reactors, centrifuges, and distillation columns will be used in the production of
biodiesel via transesterification of soybean oil with potassium hydroxide and ethanol
○ $12 million for Ethanol, $8 million for Methanol; takes approximately 3-4 years to build a
biorefinery
○ Large scale system, experienced companies/engineers who know how to operate a
biodiesel facility

18. Timeline of Project
Date Proposal
Research and
Review
Report
Preparations
Presentation
Preparations
Super Pro and
Design Work
3/4 - 3/10 X X
3/11 - 3/17 X X
3/18 - 3/24 Spring ----------- --------------------- --------------------- -------------Break
3/25 - 3/31
4/1 - 4/7
4/8 -4/14 X X
4/15 -4/21 X X X

19. References
Hassan, M. H., & Kalam, M. A. (2013). An Overview of
Biofuel as a Renewable Energy Source: Development
and Challenges. Procedia Engineering, 56, 39-53.
doi:10.1016/j.proeng.2013.03.087
Koltermann, A. (2011). Cellulosic Ethanol: Future’s Fuel
Sustainable Biofuel Production Becomes Reality.
Group Vice President Corporate Research &
Development. Retrieved April 22, 2019. Image from
article used.
Martin, J. (2016, June 23). Everything You Ever Wanted to
Know About Biodiesel (Charts and Graphs Included!).
Retrieved from https://blog.ucsusa.org/jeremy-
martin/all-about-biodiesel. Image from website used.
Biodiesel Production from Waste Cooking Oil. (2012).
Egyptian Journal of Chemistry, 55(5), 437-452.
doi:10.21608/ejchem.2012.1167
Nanaki, E. A., & Koroneos, C. J. (2012). Comparative LCA
of the use of biodiesel, diesel and gasoline for
transportation. Journal of Cleaner Production,
20(1), 14-19. doi:10.1016/j.jclepro.2011.07.026
Sheehan, J., Camobreco, V., Duffield, J., Graboski, M.,
Graboski, M., & Shapouri, H. (1998). Life Cycle
Inventory of Biodiesel and Petroleum Diesel for Use
in an Urban Bus. U.S. Department of Agriculture
and U.S. Department of Energy.
doi:10.2172/1218369
Varanda, M. G., Pinto, G., & Martins, F. (2011). Life cycle
analysis of biodiesel production. Fuel Processing
Technology, 92(5), 1087-1094.
doi:10.1016/j.fuproc.2011.01.003