Ethanol From Biomass ++++

Hawaii Ethanol Workshop: November 14, 2002

Ethanol From Cellulosic Materials Rick Elander Pretreatment R&D Team Leader Biotechnology Division for Fuels and Chemicals National Renewable Energy Laboratory Golden, CO U.S. DOE Fuel Ethanol Workshop Honolulu, HI November 14, 2002 Operated for the U.S. Department of Energy by Midwest Research Institute • Battelle • Bechtel

Lignocellulosic Biomass

Corn Stover

Bagasse Cellulose

Hardwood Other

Softwood

(Extractives, protein, ash, etc.)

(Glucose sugar)

5-20%

38-50%

15-25% 23-32% Lignin (Precursor of coal)

Hemicellulose (Other biomass sugars, esp. the pentose D-xylose)

Ethanol from Cellulosic Materials

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Hawaii Ethanol Workshop: November 14, 2002

Corn Stover—the “hot” feedstock •Up to 60 MM dry tons per year available from the 10 leading corn production states can be collected in a sustainable manner -erosion control -soil carbon levels •Enough to produce over 4 billion gallons of ethanol per year

Stover and Bagasse—Many Similarities

prote in chlorophyll

100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0%

s oil a ce tyl e xtra ctive s ma nna n ga la cta n a ra bina n Uronic a cids ash xyla n

poplar sawdust

Ethanol from Cellulosic Materials

corn stover (fresh)

bagasse (fresh)

lignin gluca n

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Hawaii Ethanol Workshop: November 14, 2002

Ethanol Production (billion gallons per year)

Ethanol from Starch and Lignocellulose

35 30 25

EXISTING

EMERGING

ADVANCED

Advanced Corn Mills

Sugar Platform -New Enzymes -Pretreatment -Fermentation

Fundamental Advances in Lignocellulose Processing and fermentation

20

9 Existing and emerging technology supports targets of a renewable fuel standard

Cellulose

15

Renewable Fuel Standard 5 bgy in 2012

10

9 Government role in high risk R&D

5

Grain

0 2000

2005

9 Advanced technology provides the leap to substantial oil displacement

2010

2015

2020

9 Industry role is to commercialize

2025

Year

Lignocellulose Conversion Processes •Concentrated acid hydrolysis (sulfuric or hydrochloric acid) •Thermochemical hydrolysis of cellulose and hemicellulose •Relatively low temperature, requires acid recovery and recycle

•Dilute acid hydrolysis (sulfuric or hydrochloric acid) •Thermochemical hydrolysis of cellulose and hemicellulose •Relatively high temperature, no acid recovery •Difficult to achieve high glucose yields without complex reactor configurations

•Pretreatment/enzymatic hydrolysis •Partial to complete thermochemical hydrolysis of hemicellulose •Various pretreatment approaches available •Enzymatic hydrolysis of cellulose and any remaining hemicellulose •Enzymes are currently too costly

Ethanol from Cellulosic Materials

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Hawaii Ethanol Workshop: November 14, 2002

Challenges for Lignocellulosic Ethanol Cellulose is much more recalcitrant than starch CH 2 OH

HO HO

Cellulose

OH

OH

Glucose

Hemicellulose largely consists of pentose sugars—more difficult to ferment

α-D-Xylose

O

Lignin—a highly aromatic, refractory heteropolymer

Arabinoxylan Lignin in agricultural residues

Generic Bioethanol Process Flow Feedstock

Steam & Catalyst

Feed Handling

Enzyme

Pretreatment

Fermentation Hydrolyzate

Recycle Water

Waste Water

S/L Sep

Broth Recycle & Condensate

Solids

Liquor

Waste Water Treatment

Waste Water

Conditioning

Distillation and Stillage Treatment

Steam

Waste Water Biogas & Sludge

Syrup Cake

S/L Sep

Ethanol

Steam

Utilities

Burner/Boiler Turbogenerator

Storage Electricity

Ethanol from Cellulosic Materials

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Hawaii Ethanol Workshop: November 14, 2002

The Key Steps Lignocellulose Feedstock Collection and Delivery

Many options exist for each of these steps…. ….and there are many interactions to consider

Pre-processing Pretreatment hemicellulose and/or lignin extraction and/or cellulose decrystallization

Conditioning

Enzymatic cellulose saccharification

Biomass sugar fermentation

Pretreatment

Lignocellulose Feedstock Collection and Delivery Pre-processing Pretreatment hemicellulose and/or lignin extraction and/or cellulose decrystallization

Conditioning

Ethanol from Cellulosic Materials

Pretreatm ent Pretreatm ents C ategory U ndergoing Second Screen AFEX /FIBEX B aseAm m onia* C atalyzed N onC atalyzed

A cidC atalyzed

Lim e Hot W ater (batch)

Hot W ater (percolation) Hot W ater-pH Neutral Nitric Acid Sulfur Dioxide Sulfuric Acid

SolventB ased C hem icalB ased

Sulfuric Acid (hot w ash process) Organosolv (Clean Fractionation) Peroxide W et Oxidation

Enzymatic cellulose saccharification

Beer Slurry to Ethanol and Solids Recovery

T echnology D evelopers and Providers Bruce D ale/M ichigan State, M BI Y.Y.Lee/Auburn M ark Holtzapple/Texas A& M Charlie W ym an/Dartm outh, M ike Antal/Haw aii Natural Energy Institute M ike Antal, Charlie W ym an M ichael Ladisch/Purdue Lee M acLean/HFTA Jack Saddler/UBC, Esteban Chornet/ U niversity of Sherbrooke BC International, Iogen, NREL, TVA, Charlie W ym an NREL NREL

Ed Lehrburger/Pure V ision

Biomass sugar fermentation

Beer Slurry to Ethanol and Solids Recovery

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Hawaii Ethanol Workshop: November 14, 2002

Pretreatment Lignocellulose Feedstock Collection and Delivery Pre-processing Pretreatment hemicellulose and/or lignin extraction and/or cellulose decrystallization

Conditioning

• The Biomass Refining Consortium for Applied Fundamentals and Innovation (CAFI) •Auburn University •Dartmouth College •Michigan State University •NREL •Purdue University •Texas A&M University •Development of comparative pretreatment data using common feedstock, analytical methods, data reporting methodology, and process economic evaluation

Enzymatic cellulose saccharification

Biomass sugar fermentation

Beer Slurry to Ethanol and Solids Recovery

Saccharification and Fermentation Lignocellulose Feedstock Collection and Delivery

• Subcontracts with the two largest enzyme producers to reduce the costs of cellulase enzymes ten-fold •Novozymes •Genencor International

Pre-processing Pretreatment hemicellulose and/or lignin extraction and/or cellulose decrystallization

Conditioning

Ethanol from Cellulosic Materials

Enzymatic cellulose saccharification

Biomass sugar fermentation

Beer Slurry to Ethanol and Solids Recovery

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Hawaii Ethanol Workshop: November 14, 2002

Saccharification and Fermentation • Robust, co-fermenting organisms need further

Lignocellulose Feedstock Collection and Delivery

development •Yeast (recombinant) •Bacteria (recombinant)

Pre-processing Pretreatment hemicellulose and/or lignin extraction and/or cellulose decrystallization

Enzymatic cellulose saccharification

Conditioning

Beer Slurry to Ethanol and Solids Recovery

Biomass sugar fermentation

Sugar and Lignin Platform Biorefinery Renewable Biomass Feedstock

Recovered Lignin

Catalyst Steam, Acid, Enzyme, etc.)

Water Steam

Purification & Drying of Lignin Product(s)

Lignin Product(s)

Unrecovered Lignin Feedstock Handling

Sugar-rich Hydrolyzate

Biomass Fractionation Recycle Water

Water Steam

Waste Water

Waste Water Treatment

Hydrolyzate & Residual Solids Make-up Water

Concentration & Purification of Sugar Product(s)

Sugar Product(s)

Unrecovered Sugars Ethanol Production & Recovery

Fuel Ethanol

Waste Water Biogas & Sludge Unrecovered Lignin Steam Generation

Ethanol from Cellulosic Materials

Residual Solids & Syrup

Steam

Steam

Power Production (Turbogenerator)

Electricity

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Hawaii Ethanol Workshop: November 14, 2002

The Biotechnology Division for Fuels and Chemicals at NREL http://www.nrel.gov/biotechnology/ http://www.ott.doe.gov/biofuels/

Acknowledgements •U.S.

Department of Energy, Office of Biomass Programs

•State

of Hawaii; Department of Business, Economic Development & Tourism; Energy, Resources, and Technology Division •BBI

International

Ethanol from Cellulosic Materials

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