Anaerobic Fermentation of Glycerol to Ethanol

318 Pages·2016·8.45 MB·English

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Department of Chemical & Biomolecular
Senior Design Reports (CBE)
Engineering
4-14-2009
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Chloe LeGendre
University of Pennsylvania
Eric Logan
University of Pennsylvania
Jordan Mendel
University of Pennsylvania
Tamara Seedial
University of Pennsylvania
Follow this and additional works at: https://repository.upenn.edu/cbe_sdr
Part of the Chemical Engineering Commons
LeGendre, Chloe; Logan, Eric; Mendel, Jordan; and Seedial, Tamara, "Anaerobic Fermentation of Glycerol
to Ethanol" (2009). Senior Design Reports (CBE). 5.
https://repository.upenn.edu/cbe_sdr/5
This paper is posted at ScholarlyCommons. https://repository.upenn.edu/cbe_sdr/5
For more information, please contact [email protected].
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The purpose of this design project is to examine the plant-scale economic viability of the anaerobic
fermentation of crude glycerol to ethanol by a hypothetical wild strain of Escherichia coli. The
manufactured ethanol, before being denatured with gasoline, has a purity requirement of 99.5% by weight.
The capacity of the ethanol plant, as suggested by the problem statement, is 50 MM gallons per year. The
process uses crude glycerol (a waste byproduct from the biodiesel industry) as a primary feedstock, so
the manufactured ethanol can be considered a “green” or renewable fuel source. The process energy
requirements must meet the current energy benchmark of 35,000 BTU/gallon of ethanol, typical for a
modern corn-to-ethanol process of this scale according to the design problem statement. This goal is
more than met, with an energy usage of 8,000 BTU/gallon of ethanol.
The process design consists of three main sections: upstream preparation of the glycerol feed for the E.
coli, anaerobic fermentation of this glycerol feed to ethanol and succinic acid (a valuable specialty
chemical and a side-product of fermentation), and downstream separation to recover the ethanol and
succinic acid.
When performing the economic analysis, the plant was assumed to be a grass roots plant located in the
Gulf Coast region of the United States. The total capital investment is $108 million, including a working
capital of $23.6 million. In the base case scenario, with crude glycerol priced at $0.05/lb, ethanol priced at
$2.50/gallon, gasoline priced at $3.15/gallon, and succinic acid priced at $2.00/lb, the net present value
(NPV) of the project is $95 MM based on an interest rate of 15%, and the investor’s rate of return (IRR) is
32.24%. The process profitability improves with increasing crude oil prices and decreasing crude glycerol
prices, which we believe are highly likely scenarios based on our market research.
DDiisscciipplliinneess
Chemical Engineering
This article is available at ScholarlyCommons: https://repository.upenn.edu/cbe_sdr/5
LeGendre, Logan, Mendel, Seedial

Anaerobic Fermentation of
Glycerol to Ethanol
Senior Design Project

Chloe LeGendre
Eric Logan
Jordan Mendel
Tamara Seedial

Submitted to:
Professor Leonard Fabiano
Professor Warren Seider
April 6, 2009

Chemical and Biomolecular Engineering CBE 459
Chemical and Biomolecular Engineering Department
University of Pennsylvania
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LeGendre, Logan, Mendel, Seedial

Professor Leonard Fabiano
Professor Warren Seider
Chemical and Biomolecular Engineering Department
University of Pennsylvania
Philadelphia, PA 19104

April 6, 2009

Dear Professor Fabiano and Professor Seider,

Contained within this report is the design of a process to convert crude glycerol to
ethanol for fuel consumption via the anaerobic fermentation of the feedstock by a wild strain of
the microorganism Escherichia coli. As suggested by industrial consultant Mr. Bruce Vrana (DuPont),
we have designed a plant to produce 50 MM gallons of denatured fuel ethanol annually using a
combination of batch fermentation and continuous processing.

The plant design that we suggest is comprised of a continuous feed preparation section, a batch
fermentation section, and a subsequent continuous separation section for the recovery of ethanol and
succinic acid (a valuable fermentation side-product). In the feed preparation section, crude glycerol, a
byproduct from the biodiesel industry, is treated to remove salts and other impurities and then mixed
with a nutrient supplement, diluted, and sterilized. In the batch fermentation section, this sterile
glycerol feed is anaerobically metabolized by the E. coli, resulting in the formation of ethanol and
succinic acid. The broth and vapor from the fermentation section are then sent to the separation section
of the plant for product recovery.

Although the design uses a hypothetical strain of Escherichia coli as per the problem statement,
researchers Dharmadi, Murarka, and Gonzalez of Rice University present a case for the same
fermentation process in existing Escherichia coli. As such, the design presented here is physically
feasible. The design has a good economic outlook, assuming that crude oil prices continue to rise and
that political support for renewable fuels continues. The process is projected to have an approximate
investor’s rate of return (IRR) of 32.24% on a total capital investment of about $108 MM. The net
present value was estimated to be $95 MM based on an interest rate of 15%. Additionally, the energy
consumption of the process was determined to be 8,000 BTU/gallon of ethanol, well below the 35,000
BTU/gallon energy benchmark provided in the problem statement.

If you have any questions, comments, or concerns regarding the report, please do not hesitate
to contact us. We want to thank you very much for your support throughout the duration of the project
and your present consideration.

Sincerely,

Chloe LeGendre Eric Logan Jordan Mendel Tamara Seedial

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LeGendre, Logan, Mendel, Seedial

Table of Contents
Abstract ................................................................................................................................................... 7
A. Process Overview .......................................................................................................................... 10
B. Importance for the Study .............................................................................................................. 11
C. Initial Project Charter .................................................................................................................... 16
Market and Competitive Analysis........................................................................................................... 17
Process Flowsheets and Material Balances............................................................................................ 24
Process Description ............................................................................................................................... 42
Fermentation Feed Preparation Section ............................................................................................. 43
Laboratory Section ............................................................................................................................. 46
Plant Seed Fermentation Section ....................................................................................................... 48
Main Fermentation Section................................................................................................................ 50
Separation Section ............................................................................................................................. 53
Energy Balance and Benchmark ............................................................................................................. 56
Unit Descriptions ................................................................................................................................... 61
Feed Preparation Section ................................................................................................................... 62
Storage Tanks: ............................................................................................................................... 62
Heat Exchangers: ........................................................................................................................... 65
Pumps:........................................................................................................................................... 66
Miscellaneous: ............................................................................................................................... 69
Seed Fermentation Train (Plant and Lab) ........................................................................................... 70
Fermenters: ................................................................................................................................... 70
Pumps:........................................................................................................................................... 73
Main Fermentation Section................................................................................................................ 77
Fermenters: ................................................................................................................................... 77
Storage Tanks: ............................................................................................................................... 79
Heat Exchangers: ........................................................................................................................... 79
Pumps:........................................................................................................................................... 80
Blowers: ......................................................................................................................................... 83
Separation Section ............................................................................................................................. 84
Storage Tanks: ............................................................................................................................... 84
Heat Exchangers: ........................................................................................................................... 85
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LeGendre, Logan, Mendel, Seedial

Pumps:........................................................................................................................................... 87
Blowers: ......................................................................................................................................... 90
Columns: ........................................................................................................................................ 91
Miscellaneous: ............................................................................................................................... 93
Unit Specification Sheets ....................................................................................................................... 97
Feed Preparation Section: .................................................................................................................. 98
Storage Tanks: ............................................................................................................................... 98
Heat Exchangers: ......................................................................................................................... 104
Pumps:......................................................................................................................................... 106
Miscellaneous: ............................................................................................................................. 112
Seed Fermentation Section (Plant and Lab): ..................................................................................... 113
Fermenters: ................................................................................................................................. 113
Pumps:......................................................................................................................................... 119
Main Fermentation Section:............................................................................................................. 126
Fermenters: ................................................................................................................................. 126
Storage Tanks: ............................................................................................................................. 128
Heat Exchangers: ......................................................................................................................... 130
Pumps:......................................................................................................................................... 131
Blower: ........................................................................................................................................ 136
Separation Section: .......................................................................................................................... 137
Storage Tanks: ............................................................................................................................. 137
Heat Exchangers: ......................................................................................................................... 142
Pumps:......................................................................................................................................... 146
Blowers: ....................................................................................................................................... 153
Columns: ...................................................................................................................................... 154
Miscellaneous: ............................................................................................................................. 156
Alternate Units and Considerations ..................................................................................................... 164
Other ................................................................................................................................................... 167
Considerations ..................................................................................................................................... 167
Environmental Considerations ............................................................................................................. 171
Economic Analysis ............................................................................................................................... 174
Equipment Cost Estimates ............................................................................................................... 175
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LeGendre, Logan, Mendel, Seedial

Utility Requirements ........................................................................................................................ 178
Operating Costs ............................................................................................................................... 181
Sensitivity Analysis ............................................................................................................................... 190
Crude Oil.......................................................................................................................................... 191
Glycerol ........................................................................................................................................... 196
Succinic Acid .................................................................................................................................... 197
Conclusion ........................................................................................................................................... 198
Bibliography ........................................................................................................................................ 200
Acknowledgements ............................................................................................................................. 204
Appendices .......................................................................................................................................... 206
Sensitivity Analysis ........................................................................................................................... 207
Correlation Example ........................................................................................................................ 207
Equipment Costing and Sizing Calculations ....................................................................................... 210
Agitators: ..................................................................................................................................... 211
Blowers: ....................................................................................................................................... 213
Crystallizer (C-1) ........................................................................................................................... 214
Distillation Towers: ...................................................................................................................... 215
Dryer: .......................................................................................................................................... 217
Electro-dialysis: ............................................................................................................................ 218
External Heat Losses from FERM1-12 ........................................................................................... 219
Fermenter Tanks: ......................................................................................................................... 220
Fermenter Tank Costs .................................................................................................................. 223
Furnace: ....................................................................................................................................... 224
Glycerol Purification System:........................................................................................................ 225
Heat Exchangers .......................................................................................................................... 226
Heat of Reaction Calculation for determining Temperature Change in Reactors ........................... 231
Molecular Sieves: ......................................................................................................................... 232
Pumps .......................................................................................................................................... 233
Reflux Accumulator: ..................................................................................................................... 238
Rotary Drum Vacuum Filter: ......................................................................................................... 239
Screw Conveyor: .......................................................................................................................... 240
Spray Nozzles for Clean-In-Place System ...................................................................................... 241
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LeGendre, Logan, Mendel, Seedial

Storage, Mixing, and Holding Tanks .............................................................................................. 242
R-101 Glycerol Purification System Patent Application ..................................................................... 244
Glycerol Purification System Supplier Information ........................................................................... 262
Specifications ............................................................................................................................... 263
Key Features ................................................................................................................................ 264
Space, Utility, and Tank Requirements ......................................................................................... 264
Maintenance ................................................................................................................................ 264
Carbon Dioxide Cap and Trade Legislation........................................................................................ 265
Problem Statement .......................................................................................................................... 269
Relevant MSDS ................................................................................................................................ 274

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LeGendre, Logan, Mendel, Seedial

Abstract
Section I

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LeGendre, Logan, Mendel, Seedial

Abstract
The purpose of this design project is to examine the plant-scale economic viability of the
anaerobic fermentation of crude glycerol to ethanol by a hypothetical wild strain of Escherichia coli. The
manufactured ethanol, before being denatured with gasoline, has a purity requirement of 99.5% by
weight. The capacity of the ethanol plant, as suggested by the problem statement, is 50 MM gallons per
year. The process uses crude glycerol (a waste byproduct from the biodiesel industry) as a primary
feedstock, so the manufactured ethanol can be considered a “green” or renewable fuel source. The
process energy requirements must meet the current energy benchmark of 35,000 BTU/gallon of
ethanol, typical for a modern corn-to-ethanol process of this scale according to the design problem
statement. This goal is more than met, with an energy usage of 8,000 BTU/gallon of ethanol.
The process design consists of three main sections: upstream preparation of the glycerol feed
for the E. coli, anaerobic fermentation of this glycerol feed to ethanol and succinic acid (a valuable
specialty chemical and a side-product of fermentation), and downstream separation to recover the
ethanol and succinic acid.
When performing the economic analysis, the plant was assumed to be a grass roots plant
located in the Gulf Coast region of the United States. The total capital investment is $108 million,
including a working capital of $23.6 million. In the base case scenario, with crude glycerol priced at
$0.05/lb, ethanol priced at $2.50/gallon, gasoline priced at $3.15/gallon, and succinic acid priced at
$2.00/lb, the net present value (NPV) of the project is $95 MM based on an interest rate of 15%, and the
investor’s rate of return (IRR) is 32.24%. The process profitability improves with increasing crude oil
prices and decreasing crude glycerol prices, which we believe are highly likely scenarios based on our
market research.

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