1. Process Evaluation and Design II – Spring 2016
Process Evaluation and Design II – Spring 2016
CHEG 407 – A
CASE 2: PROCESS DESIGN FOR ETHANOL
PRODUCTION FROM SUGARCANE
Instructor: Dr. Jacob R. Borden
Submitted by:
An Minh Tran
College of Engineering and Technology
McNeese State University
Date Submitted: May 6, 2016

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Table of Contents
Executive Summary........................................................................................................................ 3
Introduction..................................................................................................................................... 3
Overall Process Description............................................................................................................ 3
Mass and Energy Balance…………………...........................…………………………………….4
A. Milling…………………..………………..…………………………………………….4
B. Juice Clarification………………………..…………………………………………….5
C. Fermentation…………………………………………………………………………...7
D. Ethanol Distillation………………………………………………………………….....8
Major Equipment List and Purchased Cost…………………………………………………….....9
Project Economics……………………………………………………………………………….11
A. Annual Depreciation………………………………………………………………….11
B. Variables Cost of Production…………………………………………………………11
C. Annual Labor, Maintenance, and Fixed Charges……………………………………..12
D. Variables cost per gallon ethanol production…………………………………………13
E. Cash Flow and NPV Analysis………………………………………………………...13
Safety Concerns………………………………………………………………………………….14
A. Over Process………………………………………………………………………….14
B. Hazard and Operability Study (HAZOP)……………………………..………………15
Environment…………………………………………..………………………………………….17
Conclusion and Recommendation ................................................................................................ 17

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EXECUTIVE SUMMARY
Production ethanol from sugarcane included of four process: milling, juice clarification,
fermentation, and ethanol distillation. In this report, a process design for the production of
ethanol from sugarcane at St. Mary Sugar Coop plant in Jeanerette, Louisiana is introduced.
With the basic is 20,000 US ton/day of raw sugarcane that is running in 150 days/year to produce
1569 US ton/day or 71.5 MM gal/year of ethanol, the mass and energy balance, cost of major
equipment, cash flow and NPV analysis up to twenty years, and safety concern for whole of the
process are presented in this report. With the price of ethanol is $2.03/gal, the total equipment
cost is $21 MM, the revenue each year is $145 MM, tax is 34% net income, using 7% internal
rate of return, the net present value at the end of year 20th is $60MM.
INTRORUCTION
Ethanol is one of the most important substances that is used in different area such as a solvent in
producing perfumes, or making medicines and drugs. Moreover, ethanol is used as a fuel and
gasoline additive. Louisiana is one of the main states in the US that produce many important
substances from ethanol; and St. Mary Sugar Coop plant in Jeanerette, Louisiana is one of the
biggest plant of producing ethanol from sugarcane.
OVERALL PROCESS DESCRIPTION
The basic of the process is 20,000 US ton/day of sugarcane that is operated in 150 days/years to
produce ethanol. There are four main sections to produce ethanol from sugarcane. The first
section is cane milling where sugar is leached out from the bagasse through milling sugarcane.
The second section is juice clarification that is clarified juice is made from clean juice through
multi evaporators. The third section is fermentation which ethanol solution is produced with 15%
wt of ethanol, and the last section is ethanol distillation that produces 50% wt of ethanol in final

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product of ethanol solution. The figure below is present whole process of producing ethanol from
sugarcane at St. Mary Sugar Coop plant in Jeanerette, Louisiana.
Figure 1: Overall Process Flow Diagram of System
MASS AND ENERGY BALANCE
A. Milling
Figure 2: Milling Process Flow Diagram
In the milling process, 20,000 US ton/day of raw sugarcane is broken using knife mill and
hammer mill, then the crushed cane are grinded using three set of roller mill. 9000 US ton/day of
water is applied at the third roller mill and is transported to 2nd and the 1st mill for more extration

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of juice. The 6400 US ton/day with 40% solid and 60% moisture of bagasse comes from the third
mill is combusted by boiler to generate steam and electricity. After the milling process, 22,600
US ton/day raw juice with 14.7% wt% sugar and 84% wt% water is produced and is transported
to setting tank of juice clarification process.
The figure 3 and figure 4 are present for mass balance and energy of the boiler of milling section.
Figure 3: Mass Balance of Milling Process
Table 1: Energy of Boiler
For 6400 US ton/day with 40% solid and 60% moisture of bagasse, at P = 1 bar, the heat duty of
boiler that need to combusted that amout of bagasses is Q = 121,287.32 kW.
B. Juice Clarification
P 1 bar
m water 3483590.4 kg/day
T in 20 C
T sat 99.61 C
delta H 2675 kJ/kg
Cp 4.185 kJ/kg-K
Q 121,287.32 kW

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Figure 4: Juice Clarification Process Flow Diagram
The 22,600 US ton/day of raw juice coming to setting tank is transported to filter to eliminate
mud; then that clean juice with 15% wt% sugar and 85% wt% water is going to multi evaporator
with 12,439 US ton/day of steam to heat water and concentrated juice. In the concentrated juice,
the percent weight of sugar is 30% and percent weight of water is 70%. It means this process is
eliminated 11,289.6 US ton/day of water to make the juice to be more purity. It helps the
reactions in the next section that produce ethanol solution is reacted easier.
Figure 5 and figure 6 are shown in mass and energy balance of juice clarification process.
Figure 5: Mass Balance of Juice Clarification Process

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Figure 6: Energy Balance of Juice Clarification Process
For three evaporator are used in this process, total heat duty equals to 265,413 kW, and the heat
transfer coefficient is assumed 4000 W/m2-K (from chemical book), the area for eat evaporator
equals 250 m2. This number will be used to calculate the equipment cost for evaporator.
C. Fermentation
Figure 7: Fermentation Process Flow Diagram
Fermentation process is process to produce ethanol composition based on these following
equations:
Inversion of sucrose by hydrolysis:
𝐶12 𝐻22 𝑂11 + 𝐻2 𝑂 → 2𝐶6 𝐻12 𝑂6

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and conversion of invert sugars by yeast:
2𝐶6 𝐻12 𝑂6 → 4𝐶2 𝐻5 𝑂𝐻 + 4𝐶𝑂2
Following by these above equations, after 11,072 US ton/day of concentrated juice with 30%
wt% sugar coming out of reactor, the yeast of 11,072 US ton/day of yeast that 14% wt%
ethanol is produced. Then, it is transported to centrifugal; and the ethanol solution with 15%
wt% ethanol, 71% wt% water and 14% wt% CO2 is produced to lead to stripping column.
Figure 8 is show in mass balance of fermentation process.
Figure 8: Mass Balance of Fermentation Process
D. Ethanol Distillation
Figure 9: Ethanol Distillation Process Flow Diagram
Ethanol distillation process is the last process of ethanol production from sugarcane process.
Ethanol solution from previous process coming to stripping column to eliminate carbon dioxide;

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then next will lead to distillation column. After eliminate carbon dioxide in the solution, 9000
US tons/day of ethanol solution will have 17% wt% ethanol and the rest is water. And distillation
process will increase the purity of ethanol to be 50% wt%, which means 1569 US ton or 71.5
MM gallons of ethanol is produced per day.
Figure 10: Mass Balance of Ethanol Distillation Process
Figure 11: Energy Balance of Ethanol Distillation Process
Ethanol solution is cooled by cooling water of the condenser. The total heat duty of the
condenser equals 157,986 kW, and with the heat transfer coefficient equals 3000 W/m2-K. The
area of the condenser is 2178.3 m2.
MAJOR EQUIPMENT LIST AND PURCHASED COST

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Most of the unit to calculate major equipment of the process is calculated by mass and energy
balance equations that are shown above. And some of other units equipment that are used to
calculate the cost of setting tank, filter, centrifuge, stripping column, and distillation column are
shown in the figure 12 below.
Figure 12: Cost Equipment Calculation Units
Based on those units value above, and other units value that are calculate in mass and energy
balance part, the total cost of major equipment is estimated following by table 1 below.

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Table 2: Total Equipment Cost for whole Process
The total equipment cost for whole process equals $20.7MM
PROCESS ECONOMICS
A. Annual Depreciation
Annual depreciation is calculated by straight-line depreciation with the salvage value of all
equipment is estimated to be 15% of the equipment cost with the expected life of the
equipment is 20 years.
Total Equipment Cost $ 20,659,256.34
Salvage Value (15% Tot. Equip. Cost) $ 3,098,888.45
Depreciable Asset Cost $ 17,560,367.89
Depreciation Rate/Year (20 years) 5%
Annual Depreciation $ 878,018.39
Table 3: Annual Depreciation
Annual depreciation of the process equals $0.88MM
B. Variables Cost of Production
To calculate variables cost of production, the number of water comes from cooling water of
condenser and steam for the boiler, and natural gas is used for the boiler to heat water the run the
system. 101,335 US ton/day equals 24.3 MM gal/day of water is used.

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Utilities Consumption/day Cost $/unit Cost $/day Cost $/year
Water (gal) 24,285,377.26 0.005 121,426.89 18,214,032.94
Electricity (kWh) 624,987.00 0.06 37,499.22 5,624,883.00
Natural - gas (MM BTU) 10,107.28 2.178 22,013.65 3,302,047.35
Raw Material Consumption/day Cost $/unit Cost $/day Cost $/year
Sugarcane (US ton) 20,000 30 600,000 90,000,000.00
Total variable cost $/year $ 117,140,963.29
Table 4: Variable Cost of Production
The total variable cost per year of the process is $118 MM.
C. Annual Labor, Maintenance, and Fixed Charges
The calculation for annual labor, maintenance, and fixed charged are shown in table below with
the maintenance charged are 5% of the initial total equipment cost, and fixed charges excluding
depreciation are 10% of the initial total equipment cost.
Number of operators/shift 18
Operator salary $/h 20
Number of engineers 3
Engineer Salary/season 25000
Plant Manager 1
Manager salary/season 40000
Over head 100% labor cost
Total labor cost $/year $ 3,512,000.00
Maintenance (5% Total equipment cost/year) $ 1,032,962.82
Fixed Charge ( 10% Total equipment cost/year) $ 2,065,925.63
Table 5: Annual Labor, Maintenance, and Fixed Charges
D. Variables cost per gallon ethanol production
From all the costs that are calculated above, with 1569 US tons/day or 71.5 MM gal/day of
ethanol, the variables cost per gallon from ethanol production is shown in table below
Table 6: Variable Cost per Gallon Ethanol Production
$/year $/gal of Ethanol
Utilities $ 27,140,963.29 $ 0.38
Raw Material $ 90,000,000.00 $ 1.26
Depreciation $ 878,018.39 $ 0.01
Labor $ 3,512,000.00 $ 0.05
Maintenance $ 1,032,962.82 $ 0.01

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E. Cash Flow and
NPV Analysis
The sell price of ethanol is $2.03/gal with 71.5 MM gal/year of ethanol is produced, the revenue
of this project is $145 MM/year. Net Present Value (NPV) method is applied to assess the
economic value of the project. A common Internal Rate of Return (IRR) of 7% is used for
calculation. Tax is incorporated and equals 34% of the net income. The NPV of this plant is
calculated in 20 years.
Cost Revenue Tax Cash Flow NPV Total NPV to year
0 $ 20,659,256.34 $ (20,659,256.34) $ (20,659,256.34) $ (20,659,256.34)
1 $ 124,629,870.14 $ 145,116,194.90 $ 6,965,350.42 $ 13,520,974.34 $ 12,574,506.14 $ (8,084,750.20)
2 $ 124,629,870.14 $ 145,116,194.90 $ 6,965,350.42 $ 13,520,974.34 $ 10,688,330.22 $ 2,603,580.01
3 $ 124,629,870.14 $ 145,116,194.90 $ 6,965,350.42 $ 13,520,974.34 $ 9,085,080.69 $ 11,688,660.70
4 $ 124,629,870.14 $ 145,116,194.90 $ 6,965,350.42 $ 13,520,974.34 $ 7,722,318.58 $ 19,410,979.28
5 $ 124,629,870.14 $ 145,116,194.90 $ 6,965,350.42 $ 13,520,974.34 $ 6,563,970.80 $ 25,974,950.08
6 $ 124,629,870.14 $ 145,116,194.90 $ 6,965,350.42 $ 13,520,974.34 $ 5,579,375.18 $ 31,554,325.26
7 $ 124,629,870.14 $ 145,116,194.90 $ 6,965,350.42 $ 13,520,974.34 $ 4,742,468.90 $ 36,296,794.16
8 $ 124,629,870.14 $ 145,116,194.90 $ 6,965,350.42 $ 13,520,974.34 $ 4,031,098.56 $ 40,327,892.72
9 $ 124,629,870.14 $ 145,116,194.90 $ 6,965,350.42 $ 13,520,974.34 $ 3,426,433.78 $ 43,754,326.50
10 $ 124,629,870.14 $ 145,116,194.90 $ 6,965,350.42 $ 13,520,974.34 $ 2,912,468.71 $ 46,666,795.21
11 $ 124,629,870.14 $ 145,116,194.90 $ 6,965,350.42 $ 13,520,974.34 $ 2,475,598.41 $ 49,142,393.62
12 $ 124,629,870.14 $ 145,116,194.90 $ 6,965,350.42 $ 13,520,974.34 $ 2,104,258.65 $ 51,246,652.27
13 $ 124,629,870.14 $ 145,116,194.90 $ 6,965,350.42 $ 13,520,974.34 $ 1,788,619.85 $ 53,035,272.11
14 $ 124,629,870.14 $ 145,116,194.90 $ 6,965,350.42 $ 13,520,974.34 $ 1,520,326.87 $ 54,555,598.99
15 $ 124,629,870.14 $ 145,116,194.90 $ 6,965,350.42 $ 13,520,974.34 $ 1,292,277.84 $ 55,847,876.83
16 $ 124,629,870.14 $ 145,116,194.90 $ 6,965,350.42 $ 13,520,974.34 $ 1,098,436.16 $ 56,946,312.99
17 $ 124,629,870.14 $ 145,116,194.90 $ 6,965,350.42 $ 13,520,974.34 $ 933,670.74 $ 57,879,983.73
18 $ 124,629,870.14 $ 145,116,194.90 $ 6,965,350.42 $ 13,520,974.34 $ 793,620.13 $ 58,673,603.86
19 $ 124,629,870.14 $ 145,116,194.90 $ 6,965,350.42 $ 13,520,974.34 $ 674,577.11 $ 59,348,180.97
20 $ 124,629,870.14 $ 145,116,194.90 $ 6,965,350.42 $ 13,520,974.34 $ 573,390.54 $ 59,921,571.51
Table 7: Cash Flow and NPV Analysis
Fixed Charge $ 2,065,925.63 $ 0.03
Total $ 124,629,870.14 $ 1.74

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The NPV of this plant after 20 years is $60 MM. The payback period is 1 years; the profit being
earned on the second year. With the NPV equal $60 MM, which is 3 of the capital investment,
this project is worth implementing.
SAFETY CONCERN
A. Overall Process
The plant produces ethanol from sugarcane. Ethanol is a highly flammable; therefore, the
prevention for this plant, especially at fermentation and ethanol distillation process are no open
flames, no sparks, no smoking or contact with strong oxidants at that area. The acute hazards of
ethanol that effects to human body such as cough, headache, fatigue, drowsiness, dry skin,
redness, pain, or burning eyes; therefore, when people working with areas that have high
concentration of ethanol, they need to wear breathing protect, also protective gloves, and safety
goggles, specially, prevention eating, drinking, or smoking during work.

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B. Hazard and Operability Study (HAZOP)
Table 8: Hazard and Operability Study (HAZOP)

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Figure 13: Boston Square for Clean Juice of Evaporator
Figure 14: Boston Square for Reactor and Stripping Column
1, 2
3
4
5
6
7, 8
0
1
2
3
4
5
6
7
8
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0 2 4 6 8 10
Severity
Likelihood
Boston Square for Clean Juice of Evaporator
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9, 13
10, 14, 15
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0
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6
7
8
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0 2 4 6 8 10
Severity
Likelihood
Boston Square for Reactor and Stripping Column
Concentrated Juice of Reactor" Ethanol Solution of Stripping Column

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Figure 15: Boston Square for Cooling Water of Condenser
ENVIROMENT
This process produces ethanol, and also carbon dioxide, one of the harmful gas that give negative
effects to environment. The high concentration of carbon dioxide in the atmosphere will increase
the temperature of atmosphere. And this is the cause for GREEN HOUSE EFFECT. The higher
temperature of atmosphere also affect to the climate and affect the life being. The temperature is
increasing average 1oC each year. It cause the melting polar ice caps and glaciers; so increase
ocean water level; hence affects to wild life.
CONCLUSION and RECOMMENDATION
This report presents the process of producing 71.5 MM gallons of ethanol per year from the basic
is 20,000 US tons of sugarcane per day. The total capital cost of the project is $21MM, and
annual $125 MM cost for production. The sell price of ethanol is $2.03/gal with 71.5 MM
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2122
0
1
2
3
4
5
6
7
8
9
10
0 1 2 3 4 5 6 7 8 9 10
Severity
Likelihood
Boston Square for Cooling Water of Condenser

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gal/year of ethanol is produced, the revenue of this project is $145 MM/year. The payback period
of this project is one year and the project starts to earn profit from 2nd year. At the end of 20th
year, NPV is $60 MM. The recommendation for this project is adding a treatment system for
carbon dioxide to reduce amount of carbon dioxide to environment, also can use it to produce
soft drink such as coke or diet coke.