Pretreatment Fundamentals

Transcription

1 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 2006 Annual International Convention Chicago, Illinois April 12, 2006 Biomass Refining CAFI

2 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 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

3 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

4 DOE USDA Project: September 2004 to 2007 Enzymatic Digestion of Corn Stover and Poplar Wood after Pretreatment by Leading Technologies Water, AFEX, acid pretreatments Hydrolysis characteristics Mixed 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 Biomass Refining CAFI

5 CAFI 1: Corn Stover Glucan Xylan Arabinan Mannan Galactan Lignin Protein Acetyl Ash Uronic Acid Non-structural Sugars 36.1 % 21.4 % 3.5 % 1.8 % 2.5 % 17.2 % 4.0 % 3.2 % 7.1 % 3.6 % 1.2 %

6 CAFI 2 Standard Poplar Component Composition (wt %) Glucan 43.8 Xylan 14.9 Arabinan 0.6 Mannan 3.9 Galactan 1.0 Lignin 29.1 Protein nd Acetyl 3.6 Ash 1.1 Uronic Acids nd Extractives 3.6 Biomass Refining CAFI

7 Key Comparisons: Per 100 lbs Poplar Corn Stover Glucan (cellulose) Xylan (hemicellulose) Lignin Ash Energy in Lignin (est) 116,000 86,000 Ethanol (at 90% Yield)

8 Pretreatment is needed to get us there Feedstock Preparation Biomass Pretreatment Enzyme hydrolysis Ethanol Fermentation

9 Effect of Pretreatment Lignin Cellulose Amorphous Region Pretreatment Crystalline Region Hemicellulose

10 Pretreatment Modeling K C C* k 1 k 2 k G 3 k 4 n G Degradation k 2, k 3, >> k 1

11 Pretreatment Converts Cellulose to Reactive Form K C C* k 1 k 2 k G 3 k 4 n G Degradation

12 Enzymes convert cellulose to glucose and xylan to xylose (no degradation products) C k 2 > k 1 k 1 G n k k 4 3 X,G Degradation Products H,C* k 2 C = native cellulose H = hemicellulose (xylan) C* = hydrated cellulose G n = glucans (oligosaccharides) G = glucose (monomer) X = xylose (monomer)

13 Yeast Metabolism: pentose fermentation NAD(P)H Xylose Glucose NAD(P)+ NAD+ Xylitol Glucose-6-P NADH Xylulose Fructose-6-P Xylulose-5-P Glyceraldehyde-3-P NAD+ Ho et al PPP NADH 3-Phosphoglycerate Phosphoenolpyruvate NADH NAD+ Ethanol TCA Cycle Pyruvate Acetaldehyde

14 Several Pentose Fermenting Microbes Yeast (Ho et al) E. coli (Lonnie Ingram et al) Zymomonas (NREL)

15 Using Hay 1 Bale = 970 lbs = 2000 miles Assuming 50 gal x 40 mpg