Enzyme Applications for the Fuel Ethanol Industry

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Enzyme Applications for the Fuel Ethanol Industry

• AIDA
• International Technical Symposium
• New Delhi
• 20 March 2008

Mary Chan Customer Solutions
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Topics

• Ethanol Industry Overview
• Various Feedstocks
• What are Enzymes
• Enzymes for ethanol production from starch
• Ethanol Process Overview
• Cooking and Liquefaction
• SSF (Simultaneous Saccharification
  Fermentation)
• Theoretical ethanol yields

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Ethanol as a Fuel Source

• Ethanol the first fuel used by the pioneers of
  the automobile industry.
• Ethanol more than a source of power
• High octane, replaces carcinogenic aromatics and
  tetraethyl lead
• High oxygen content, without the problems of
  ethers such as MTBE
• Reduces carbon dioxide emissions, because the CO2
  produced is reabsorbed by the starch crops.
• Reduces dependence on Middle Eastern crude oil
• Helps support the local agricultural economy
• Proven in billions of kilometers of use in all
  climates in high performance, economy, and truck
  engines.
• Used in millions of cars.
• Most cars in Brazil are flex-fuel vehicles,
  allowing 95 ethanol or lower blends. Regular
  gasoline contains 25 ethanol in Brazil
• In the U.S., almost 40 of the gasoline sold
  contains 10 ethanol.
• There are over five million flexible fuel
  vehicles on the road in the U.S. These vehicles
  can use E-85 (85 ethanol), E-10 (10 ethanol),
  or straight gasoline equally well.

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Ethanol Cost of Production

• Ethanol production cost depends on several key
  factors
• The cost of the raw materials (Corn, cassava,
  wheat, molasses)
• The cost of energy (Natural gas, coal, bagasse)
• The value of the coproducts (Distillers dry
  grains, electricity)

Plant investment costs are about 1.50 per U.S.
gallon (USD 0.40 per litre) of annual capacity
for a grain-based plant. This value can be higher
for small plants or unusual feedstocks. It can be
lower for large corn plants.
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Ethanol Cost of Production
Total Cost USD 0.40/Litre EtOH
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State of the Industry

• Brazil produces more than 18 billion liters of
  ethanol per year for automotive use.
• U.S. produces over 20 billion liters, mostly
  blended with gasoline as a 10 mixture.
• Currently there are over 100 ethanol plants in
  the U.S. with many more under construction.
• U.S. legislation requires 30 billion liters of
  renewable fuels in use by 2008.
• Europe has just begun their development, with
  almost one billion liters of production.

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Global fuel ethanol production has doubled in the
past 5 years, and will continue to grow at 20
plus annually through 2010
World Fuel Ethanol Production(2002-2010F)
77.5
Total
Others
China
67.1
Europe
54.8
Millions of MT
USA
44.5
35.5
23.4
22.5
21.4
17.4
Brazil
Source F.O. Licht, Novozymes Analysis
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Advantages of Various Grains as Feedstocks

• Maize (corn) Easily transported and stored,
  well-developed agricultural machinery, valuable
  coproduct (distillers grains for cattle)
• Wheat and barley the same as maize, but better
  suited to shorter and colder climates.
• Cassava high starch content, and can be
  produced in tropical climates where grains cannot
  grow.
• Lignocellulosic biomass a universally available
  source of carbohydrate, but commercially viable
  collection and pretreatment is yet to be
  developed.

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Various Starch Properties
Raw material Gelatinisation temp., C Starch content wt as is EtOH yield, ltr/100 kg Protein content,
Barley 53 - 63 54 - 65 34 - 41 9 - 14
Corn 68 - 74 60 - 63 38 - 40 9 - 10
Corn Starch 62 - 74 71 - 74 45 - 47 8 - 12
Tapioca Roots 51 - 65 20 - 30 13 - 20 1 - 4
Tapioca Meal 51 - 65 65 - 80 40 - 50 0.5 - 2
Rice 65 - 75 65 - 70 40 - 44 7 - 9
Rye 55 - 70 55 - 62 35 - 37 8 - 16
Sorghum (Milo) 70 - 78 55 - 65 36 - 42 8 - 10
Wheat 58 - 65 58 - 62 36 - 39 10 - 14
Wheat Starch 52 - 75 67 - 69 42 - 44 0.4 - 0.5
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What are enzymes?
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What are enzymes?

• Enzymes are natures catalysts
• Enzymes are not living organisms, but found in
  all living organisms
• Enzymes are efficient and specific...if you treat
  them right !
• Industrial enzymes are made by micro-organisms
• Functional proteins made up of chains of amino
  acids linked together by peptide bonds.
• Highly specific - named for the substrate they
  work on, i.e. proteases for proteins,
  amylases for amylose and amylopectin, etc.
• Safe, however, good chemical hygiene is always
  recommended.
• Work under mild conditions
• Replace harsh chemicals such as strong acids
• Biologically degradable
• A clean technology

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Enzymes are specific catalysts
Substrate Starch
http//www.labbench.com
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Enzymes are used to produce many of the products
we use everyday

• Enzymes normally
• Reduce energy water consumption
• Reduce the need for harsh chemicals
• Reduce the amount of by-products
• Improve yields

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Enzymes are natural and produced by fermentation
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From Grain to Ethanol(and how enzymes make this
possible)
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• What roles do enzymes play in the operation of an
  ethanol plant?

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What does it take to turn starch into ethanol?

• Yeast cannot take up large starch molecules
  (Dextrins)
• Starch must be converted into simple sugars, such
  as glucose

Conversion
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The Fuel Ethanol Process
Break down starch to dissolved sugars (Enzymes
convert starch to simple sugar)
Fermentation of sugar to produce ethanol (Yeast
converts glucose into ethanol)
Purify ethanol to a concentrated
form (Distillation)
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Typical Ethanol Production Process from Starch
Sources
31 C
85 C
85 C
105 C
33 C
85 C
33 C
80 C
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Why Where Enzymes are Added
Jet Cooker
a-amylase Ammonia
Lique- faction
Slurry
a-amylase
Fermentation
Yeast nutrients
Glucoamylase (Protease)
Starter Yeast Yeast nutrients
Yeast propagator
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Enzymes for the production of Fuel Ethanol from
Starch

• Liquefaction
• Liquozyme SC
• Liquozyme SC DS
• Saccharification
• Spirizyme Fuel
• OPTIONAL ENZYMES depending on raw materials
• Viscosity Reduction
• Viscozyme range of enzymes
• Viscozyme Wheat, Viscozyme Barley, Viscozyme Rye.
• Protein hydrolysis to produce FAN for yeast
  nutrition
• Alcalase 2.5L DX

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Enzymes and Operating Conditions
Enzyme Dosage pH Temp., C
  w/w raw material as is    
Liquozyme SC DS 0.01 - 0.02 5.0 - 6.0 85 - 110
       
Spirizyme Fuel (SSF) 0.046 - 0.066 3.5 - 4.5 30 - 35
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Liquefaction The cook process
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Slurry Tank

• Heat via steam injection or other is added to
  allow the enzyme to start the liquefaction
  process
• (aka primary liquefaction)
• Starch begins to gelatinize, swelling with
  water and causing viscosity increase
• Agitation is very important!
• Alpha amylase is added to reduce the viscosity
  and make mash pumpable
• Targets (very important)
• Temperature 182-185oF (82 85 C)
• DE target 4-6
• pH 5.6-5.8

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Hydroheater - Jet Cooker
Steam
?p 30 - 50 psi
Mash
Time
Temperature
Shear
Helps make dextrins accessible for enzyme action!
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Cook/Liquefaction

• Primary Liquefaction
• Gelatinize the starch
• Rapidly reduce the viscosity of the gelatinized
  mash
• Keep a low DE before the jet (4-6)
• Secondary Liquefaction
• Converts large starch molecules to dextrins
• Dextrin formation measured by DE
• - Final DE Target is 10-12
• Further decrease the mash viscosity which
  increases heat exchanger efficiency

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Viscosity Reduction Demo

• Mix cassava flour boiling water
• Note it becomes thick - viscosity increase from
  starch gelatinization
• Add 1 drop LiquozymeSC DS
• Ensure good agitation
• Note rapid viscosity break

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SSF Simultaneous Saccharifaction Fermentation
Yeast Nutrition and Production of Alcohol
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SSF

• Simultaneous Saccharification and Fermentation
• Spirizyme Fuel glucoamylase generates
  fermentable sugar (glucose) in the fermenter at
  the same time as the yeast is converting the
  sugar to ethanol.

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SSF Process Flow
Mash from Liquefaction
CO2 to Scrubber
Mash Coolers

• Batch Fermentation
• Spirizyme Fuel
• is added to the
• fermenters via
• the mash fill
• header.

Water
Yeast Propagator
Ferm. 1
Ferm. 2
Ferm. 3
Ferm. 4
Spirizyme Fuel, Yeast
To Beerwell and Distillation
90 - 93oF (32 34 C) pH 3.8 - 5.0
88 - 90oF (31 - 32C) pH 3.6 - 4.0
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What does Glucoamylase do?

• Glucoamylase generates simple sugars that the
  yeast can use in the fermenter
• At the same time, the yeast are converting the
  sugar to ethanol!

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Glucoamylase action

• Gluco-amylase breaks down long glucose chains
  (dextrins) into individual glucose molecules

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What Happens in Fermentation?

• Glucose Ethanol CO2
• Heat
• Remember Fermentation is a race between the
  yeast and undesirable bacteria!
• Practice good plant sanitation!

Yeast
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ETHANOL YIELD FROM STARCH

• hydrolysis fermentation
• Starch ------------gt Glucose -----------gt Ethanol
• C6H10O5n-----gtnC6H12O6-----gt2nCO2 C2H5OH
• 162 180 44 46

1000 kg starch ? 2 x 46 x 1000 568 kg
ethanol 720 litres ethanol 162
Density of alcohol 0.789 g/l
Typically in the industry, the yield efficiency
is 93 of the theoretical. So realistically, one
ton of, say, corn, with 70 starch content, will
give about 468 litres of ethanol.
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A Bushel of Corn is 25kg (56lbs)
Wet Corn 25 kg
Starch 15.3 kg
Sugars 17 kg
Ethanol 8.1 kg(93 efficiency)
CO2 7.7 kg(93 efficiency)
Heat 1,542 kcal
DDG 7.6 kg
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In Conclusion..

• The ethanol industry is expanding at a very rapid
  rate, providing environmentally acceptable fuels
  while improving local economics.
• Today, the reliability of the technology, the
  yeast, and the enzymes are such that the process
  is robust and reliable.

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CONCEPT SUPERGRAPHICS ANIMATION WITH
LOOP EXPERIENCE NICE LIGHT EFFECT. THE
ANIMATION LOOPS AND CAN BE USED AS A PAUSE SCREEN
OR AGENDA DIVIDER. ANIMATION TIME UNLIMITED NOT
ICE NEEDS TWO MOUSE CLICKS TO ADVANCE TO NEXT
SLIDE IN PRESENTATION

• Thank Youfor your attention Please visit our
  websitewww.novozymes.com