Pretreatment Fundamentals

Bruce E. Dale, Richard T. Elander, Mark T. Holtzapple, Rajeev Kumar, Michael R. Ladisch, Yoon Y. Lee, Nate Mosier, Jack Saddler, Mohammed Moniruzzaman, Charles E. Wyman

CAFI

BIO 2006Annual International Convention

Chicago, IllinoisApril 12, 2006

Biomass Refining CAFI

Biomass Refining Consortium for Applied Fundamentals and Innovation (CAFI):

Who we are….Pretreatment researchers working together in a

coordinated, disciplined way to understand the fundamentals underlying lignocellulosic biomass pretreatment and hydrolysis. Organized in 1999 -2000

CAFI recognizes that pretreatment is part of a system that includes hydrolysis and fermentation—pretreatment effects on downstream processes must be understood

Biomass Refining CAFI

USDA IFAFS Project: September 2000 to 2003

• USDA Initiative for Future Agriculture and Food Systems Program for comparative information on leading cellulosic biomass pretreatments with common source of corn stover and identical analytical methods– Aqueous ammonia recycle pretreatment - YY Lee, Auburn University– Water only and dilute acid hydrolysis by co-current and flowthrough

systems - Charles Wyman, Dartmouth College– Ammonia fiber explosion (AFEX) - Bruce Dale, Michigan State

University– Controlled pH pretreatment - Michael Ladisch, Purdue University– Lime pretreatment - Mark Holtzapple, Texas A&M University– Logistical support and economic analysis - Rick Elander/Tim Eggeman,

NREL through DOE Office of the Biomass Program funding• Emphasis on quality not quantity• Concluded September, 2003

Biomass Refining CAFI

DOE USDA Project: September 2004 to 2007

Biomass Refining CAFI

Enzymatic Digestion of Corn Stover and Poplar Wood after Pretreatment by Leading Technologies

Water, AFEX, acid pretreatmentsHydrolysis characteristicsMixed sugar fermentations using yeast

Researchers: Charles E. Wyman, Dartmouth College/University of California, Rajeev Kumar, Dartmouth College, Bruce E. Dale, Michigan State University, Richard T. Elander, National Renewable Energy Laboratory, Mark T. Holtzapple, Texas A&M University, Michael R. Ladisch, Nate Mosier, Nancy Ho, Purdue University, Y. Y. Lee, Auburn University, Mohammed Moniruzzaman, Genencor International, John N. Saddler, University of British Columbia

CAFI 1: Corn StoverGlucan 36.1 %

Xylan 21.4 %

Arabinan 3.5 %

Mannan 1.8 %

Galactan 2.5 %

Lignin 17.2 %

Protein 4.0 %

Acetyl 3.2 %

Ash 7.1 %

Uronic Acid 3.6 %Non-structural Sugars 1.2 %

Biomass Refining CAFI

Component Composition (wt %)Glucan 43.8Xylan 14.9

Arabinan 0.6Mannan 3.9Galactan 1.0

Lignin 29.1Protein ndAcetyl 3.6Ash 1.1

Uronic Acids ndExtractives 3.6

CAFI 2 Standard Poplar

Key Comparisons: Per 100 lbs

Poplar Corn StoverGlucan (cellulose) 43.8 36.1

Xylan (hemicellulose) 14.9 21.4

Lignin 29.1 17.2

Ash 1.1 7.1

Energy in Lignin (est) 116,000 86,000

Ethanol (at 90% Yield) 4.9 4.8

Ethanol Fermentation

Pretreatment is needed to get us there

Feedstock Preparation

Biomass Pretreatment

Enzyme hydrolysis

Crystalline Region

Amorphous Region

CelluloseLignin

Hemicellulose

Effect of Pretreatment

Pretreatment

Pretreatment Modeling

C

C*

Gn G Degradation

k1

k2

k3k4

K

k2, k3, >> k1

Pretreatment Converts Cellulose to Reactive Form

C

C*

Gn G Degradation

k1

k2

k3k4

K

Enzymes convert cellulose to glucose and xylan to xylose (no degradation products)

C

H,C*

Gn X,GDegradation Products

k1

k2

k3

k4

C = native celluloseH = hemicellulose (xylan)C* = hydrated celluloseGn = glucans (oligosaccharides)G = glucose (monomer)X = xylose (monomer)

k2 > k1

Yeast Metabolism: pentose fermentation

Glucose

Glucose-6-P

Fructose-6-P

3-Phosphoglycerate

Phosphoenolpyruvate

Pyruvate Acetaldehyde

Ethanol

TCA Cycle

Xylose

Xylitol

Xylulose

Xylulose-5-PGlyceraldehyde-3-P

NAD(P)H

NADH

NADH

NADH NAD+

NAD+

NAD(P)+

NAD+

PPP

Ho et al

Several Pentose Fermenting Microbes

Yeast (Ho et al)

E. coli (Lonnie Ingram et al)

Zymomonas (NREL)

1 Bale = 970 lbs = 2000 miles

Using Hay

Assuming 50 gal x 40 mpg