Enzymatic Conversion of Biomass to Ethanol

Transcription

1 Enzymatic Conversion of Biomass to Ethanol Alfalfa/Corn Rotations for Sustainable Cellulosic Biofuels Production June 29-30, 2010 Pioneer Hi-Bred Carver Center Johnston, IA

2 2 Genencor, a Danisco Division 1982 Genentech and Corning Produce over 300 protein products (enzymes) Markets: Biofuels, Biorefineries, Textiles, Cleaning, Food and Beverage, Biodefense Research and Development in Palo Alto, CA Applied Innovation Center in Cedar Rapids, IA 9 Plants worldwide, 2 in US

3 3 Biomass Conversion Processes Biochemical Uses enzymes and microorganisms to convert biomass to fermentable sugars and then alcohols. (Mascoma, DDCE) Reference: Corn CAPEX= $2.00/gal Yield=100 gal/ton 2010 CAPEX= $6.16/gal Yield= 60 gal/ton 2020 CAPEX= $3.30/gal Yield= 88 gal/ton Thermochemical Uses gasification to produce syngas that is converted to alcohol by catalysts. (Range Fuels) 2010 CAPEX= $6.00/gal Yield= 75 gal/ton 2020 CAPEX= $4.00/gal Yield= 105 gal/ton Biothermal Uses gasification to produce syngas that is fermented to alcohols with microorganisms. (Coskata) 2010 CAPEX= $5.00/gal Yield= 90 gal/ton 2020 CAPEX= $3.00/gal Yield= 105 gal/ton

4 4 Biochemical Cellulosic Ethanol Convert the cellulose (C6) and hemicellulose (C5) to sugars and ferment the sugars to ethanol. Use the lignin for a fuel source. Production of fermentable sugars is difficult and expensive Pentose, xylose (C5) sugars are hard to ferment to ethanol Requires very large volumes of enzymes to produce the sugars Yields: Corn: gal/ac Alfalfa: 350 gal/ac??? Corn w/ biomass: 600+ gal/ac Switchgrass: 1,000 gal/ac Sugar corn : 1,200 gal/ac Miscanthus: 1,500+ gal/ac

5 5 Structure of Biomass Structure of Biomass Recalcitrance of Biomass Plants were designed by Mother Nature to stand upright and resist harsh environmental conditions Deconstruction of cell wall is difficult and expensive Sugar Eat it now for energy Starch Store it and eat it later Cellulose Build your house out of it

6 Structure of Biomass Cellulosic biomass is highly recalcitrant. Cellulose (6-carbon sugars) fibers are highly structured and hard for enzymes to reach Hemicellulose (mostly 5-carbon sugars) bind in and around the cellulose backbone Lignin (complex aromatic polymer) acts as a glue covering and binding everything Lignin Pretreatment Goal: Make cellulose more accessible to enzymatic breakdown (hydrolysis) and solubilize hemicellulose sugars Cellulose Pretreatment Simplified model of plant primary cell wall Figure adapted from Somerville, C. et al Science 306(5705), Hemicellulose Figure adapted from N. Mosier et al Bioresource Technology 96(6),

7 7 Cellulosic Enzyme Coctails Cellulase Breaks down cellulose into highly fermentable C6 sugars or glucose. Fermentable by yeasts and other microbial organisms. Hemi-cellulase Breaks down hemicellulose into hard to ferment C5 sugars called xylose or pentose. Not fermentable by yeast. Subject to substantial amount of ethanologen bug research. Beta Glucanase Breaks down complex oligosaccharides called beta glucans. Conversion to glucose makes them fermentable. Beta Glucosidase Converts cellobiose, a product of cellulose degradation into glucose. Accellerase DUET contains 40+ different enzyme activities

8 8 Dual Cellulosic Ethanol Strategy Accellerase family of Products Result of 25 years of cellulase research and development Accellerase DUET launched February, 2010 Accessory or booster products: XC, XY, BG Works with all common feedstocks and pretreatment processes

9 9 Dual Cellulosic Ethanol Strategy DuPont Danisco Cellulosic Ethanol, DDCE Joint venture between DuPont and Danisco (Genencor) Develop and deliver an integrated process technology for cellulosic ethanol production Demonstration plant in Vonore, TN started up December, 2009 Operated by Genera Energy, LLC (University of Tennessee) Corn cobs 2010 >>>>> Switchgrass 2011

10 10 Cellulosic Ethanol Process Combinations FEEDSTOCK PRE-TREATMENT ENZYME HYDROLYSIS FERMENTATION Alfalfa Energy Crops Corn stover Corn cobs Wood pulp Sugarcane bagasse Municipal solid waste Recycled paper Dilute Acid Ammonia Fiber Expansion (AFEX) Steam Explosion Hot water Others?? The choice of feedstock and pretreatment has a big impact on composition and dose of enzymes required. Feedstocks will vary by geography

11 11 Barriers to Cellulosic Ethanol Production Technical Pretreatment Hydrolysis Fermentation Enzyme production and activity Process efficiency Economic Policy Capital cost per unit of fuel produced ($/gal) Feedstock costs ($/ton) Delivered enzyme costs (<$0.50/gal) Blend Wall to 15%...need room to run! Loan guarantees for construction Tax credits and tariffs

12 12 Thank You Bob Randle Commercial Development, Fuel Ethanol Genencor, a Danisco Division office cell bob.randle@danisco.com