Proprietary and Confidential © Copyright 2007 Pavilion Technologies

Ethanol From Corn Process

Dry Mill Ethanol Process Lina M Rueda

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The Distillery Flow Diagram: From Corn to Ethanol Plus Co-products

1 bushel of corn (56 lbs)

Starch (32 lbs)

Milling

Fermentable sugar

(36 lbs)

Liquefaction

Saccharification

Ethanol

(17.6 lbs)

+DDGS(17 lbs)

+Heat

(7450 BTU)

+CO2

(18.4 lbs)Fermentation

Recovery

Dryhouse

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Fermentation Fundamentals

• Key Ingredients

- Starch (sugar source)

- Enzymes (breakdown of starches)

- Yeast (conversion of sugar to ethanol)

• Key Process Components

- Enzyme addition

- Yeast propagation

- Fermentation cycle

- Cooling system

EnergyCOOHHCOHC 2556126 22

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Process Description• Milling

• Cooking and mixing

- Milled corn and cook water

- a-Amylase to break down long polymer chains (starch), reduce solids

- Solubilization of sugars

- Release of bound sugars: starch is bound to protein and fiber which is released during cooking

- Gelatinization: absorb water so enzymes can react with molecules

• Liquefaction

- Using a-Amylase to break down starches to shorter chain molecules

• Saccharification and Fermentation

- Batch processs (~ 50-60 hours)

- Exothermic

- Glucoamylase is used to break down short chained molecules to glucose

- Yeast is added to convert glucose to ethanol

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Water Balance

8 8

Methanator

Slurry Tank

Process Water

Liquefaction

Backset

Beer Feed

Milling

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Fermentation

8

Slurry Tank

Liquefaction

Backset

Beer Feed

FermenterYeast Propagation

Enzymes

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• Distillation

- Separate Ethanol from non-fermentable components

• Dehydration

- Azeotropic Distillation

- Molecular Sieves

• Non-Fermentables

- Centrifugation

- Evaporation

- Drying

Process Description

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Distillation

Beer Feed

Evap. SteamSteam Flow

Sieve Back Pressure

Rectifier Reflux Sieve Feed

Vaporizer Temperature

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Dryer, Evaporator and TO

Steam Flow

Centrifuge Feed

Whole Stillage

Thin Stillage

Syrup Tank

Wet Cake Pad

Evaporators

Dryers

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Control Strategy

Ethanol Plant-Wide Optimizer

Dryer Evap TOAPC&

Distill/Sieve APC

Fermentation APCSlurry/WaterbalanceAPC

Mv setpointsPlant and constraintMeasurements (CV)

Energy, feedstock,

Product Values

$ costs