Advanced Bioproduct Systems: Ethanol Production
Summary of Lecture Six
Dry Grind Corn Process
Ground corn
Mixing
25% solids
Adjustment from
6.0 to 4.0 pH
Liquefaction
(90°C, 90 min)
Water
Dextrins
Lecture Seven
Starch
Enzyme and yeast addition
Ethanol Process Modeling Using SuperPro
DDGS
Ethanol
Drying
Beer boiling
(85°C, 2 hr)
Saccharification and
fermentation
(30°C)
Ethanol
Yeast
Sugars
Advanced Bioproduct Systems: Ethanol Production
Objectives of Process Modeling
Summary of Lecture Six
Biomass
Cleaning
Cellulosic Ethanol Production Process
Size reduction
Pretreatment
Process models are developed to
Liquid stream (Rich
in hemicellulose)
Ethanol
Conditioning
Distillation
Solids (Cellulose
and lignin)
SSF
Drying
Visualize process
Model process flows
Perform mass and energy balances
Evaluate process economics
Evaluate emissions and
Investigate scale up scenarios
Investigate effect of process modifications
Some of the commercially available process modeling software are:
1.
2.
3.
Pentose
Fermentation
Centrifugation
1.
2.
3.
4.
5.
6.
7.
Aspen Plus
SuperPro designer
Biopro designer
Lignin rich coproduct (for
heating and power
generation
Advanced Bioproduct Systems: Ethanol Production
Biological and Ecological Engineering Department
1
Process Modeling
Following sequence of steps are followed to develop a process flow simulation
model.
•
Specify overall mode of operation
•
Register pure components and mixtures
•
Build flow sheet
•
Initialize operations in procedures
•
Initialize input streams
•
Initialize scheduling
•
Define process sections (optional)
•
Adjust convergence parameters (optional)
•
Solve mass and energy balances
•
View simulation results
Ref: SuperPro Designer User Manual
Biological and Ecological Engineering Department
Economic and Emission Analysis
To develop economic evaluation, throughput analysis, and environmental
impact assessment
1.
2.
3.
4.
5.
6.
7.
8.
9.
Classify streams and supply stream-related cost data
Adjust the equipment level capital & operating cost factors (optional)
Adjust the operation level operating cost factors (optional)
Adjust the section level capital investment factors (optional), and adjust the
section level operating cost factors (optional)
Adjust the process level economic evaluation parameters
Perform economic calculations and generate reports (optional)
View cost analysis and economic evaluation reports
Adjust annual production by scaling up or scaling down the process
throughput
View throughput analysis results, environmental impact assessment and
emissions reports
Ref: SuperPro Designer User Manual
Biological and Ecological Engineering Department
Process Modeling Example
A corn dry grind ethanol plant of 15 million gal/year capacity has following inputs.
Develop a process simulation model using SuperPro.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Ethanol production : 15 million gal.
Liquefaction efficiency: 90%
Saccharification efficiency: 90%
Fermentation efficiency: 98%
Corn composition : 13% moisture, 66% starch, 9% protein, 8.5% oil and 3.5%
ash)
Enzyme usage: Alpha amylase and glucoamylase: 0.35% w/w starch;
Yeast: 0.35% starch
Sulfuric acid: 0.1% corn weight
Relative volatility of ethanol: water 3:1
Heating source: steam.
Coproduct: wet DDGS and thin stillage
A hammer mill with a rated grind rate of 10,000kg/hr costs $500,000 in 2004.
Use a power law coefficient of 0.6 for sizing.
Biological and Ecological Engineering Department
Thank you
Advanced Bioproduct Systems: Ethanol Production
2