Trash into Gas: Powering Sustainable Transportation by Plants

Transcription

1 Trash into Gas: Powering Sustainable Transportation by Plants Jaclyn D. DeMartini Dr. Charles E. Wyman University of California Chemical and Environmental Engineering Department Center for Environmental Research and Technology October 20, 2011

2 Sustainable Alternatives for Transportation Sustainable Resources Primary Intermediates Secondary Intermediates Human Needs Sunlight Wind Ocean/ hydro Biomass Organic Fuels Transportation Geothermal Electricity Hydrogen Nuclear By Lee Lynd, Dartmouth Batteries 2

3 Focus: Cellulosic Biomass - Abundant, Renewable, Inexpensive Existing resources Agricultural wastes - Sugar cane bagasse - Corn stover and fiber Forestry wastes - Sawdust Municipal wastes - Waste paper - Yard waste Industrial waste - Pulp/paper sludge Future resources Dedicated crops - Herbaceous - Woody Not sugar or starch crops such as used for making ethanol in Brazil and the U.S. respectively 3

4 DOE and USDA recently estimated 1.3 billion tons of cellulosic biomass could be available Includes 368 million dry tons from forests and 998 million dry tons from agriculture Equivalent to about 130 billion gallons of ethanol replace about 2/3 or more of 130 billion gallons of gasoline used annually 4

5 Cellulosic Biomass Composition Cellulose 43% Hemicellulose 27% Lignin 17% Other 13% Agricultural Residues Sugars! Cellulose 45% Hemicellulose 25% Lignin 22% Extractives 5% Ash 3% Woody Crops Cellulose 45% Other 9% Municipal Solid Waste Ash 15% Lignin 10% Hemicellulose 9% Other carbohydrates 9% Protein 3% Cellulose 45% Hemicellulose 30% Lignin 15% Other 10% Herbaceous Energy Crops 5

6 How are sugars stored in plants? Sugars are stored as high molecular weight polymers in plant cell wall Complex, crosslinked matrix Polysaccharides (cellulose, hemicellulose, pectin) Lignin Protein Zhang and Lynd, 2004 Image from genomics.energy.gov

7 Challenge: How Do You Put Low Cost Sugar from Biomass in Your Car? 7

8 1. Biological Processing of Biomass Biological processing of cellulosic biomass offers the potential of high yields vital to economic success stoichiometry and energetics High selectivity also reduces problematic byproducts Biological processing can take advantage of the power of biotechnology to dramatically reduce costs Ethanol is a natural product for biological conversion processes 8

9 1. Biological Processing of Biomass Biological processing of cellulosic biomass offers the potential of high yields vital to economic success stoichiometry and energetics High selectivity also reduces problematic byproducts Biological processing can take advantage of the power of biotechnology to dramatically reduce costs Ethanol is a natural product for biological conversion processes 9

10 1. Biological Processing of Biomass Enzyme production Biomass production Harvesting, storage, size reduction Pretreatment Enzymatic hydrolysis Sugar fermentation Hydrolyzate conditioning Hydrolyzate fermentation Ethanol recovery Residue utilization Waste treatment 10

11 How do we get sugars out of plant cell walls? 1. Pretreatment is the first step to reduce biomass recalcitrance Heat Lignin Cellulose Disruption Hemicellulose

12 How do we get sugars out of plant cell walls? 2. Enzymes are added to convert sugar polymers into monomers Lignin Cellulose Hydrolysis Xylose Xylose Xylose Xylose Hemicellulose Xylose

13 How do we get convert sugars to fuel? Xylose Xylose Xylose Xylose Fermentation C 2 H 6 O Ethanol Xylose

14 2.Thermochemical Conversion of Biomass: Making Sugar Degradation Products for Jet Fuel Biomass 15-20% Lignin 40-50% Cellulose 25-35% Hemi cellulose Xylose Furfural 5-HMF Ethanol Levulinic acid Formic acid Chemical reaction Increasing temperature/ time

15 2.Thermochemical Conversion of Biomass: Making Sugar Degradation Products for Jet Fuel Jet Fuel xylose xylitol C9-C10 Hemicellulose (xylan 18%) Cellulose (42%) Lignin (25%) 87.5% yield Levulinic acid Formic acid 75% yield Hydrogenation, dehydration. dehydration/ hydrogenation dehydration, purification, oligomerization, hydrogenation C8-C24 Our work starts with biomass to building blocks other than pure chemicals. Lignin humins 75% yield Catalytic fast pyrolysis Arene

16 Example Experimental Systems 4 Pretreatment tubes Pretreatment reactor Fermentors Pretreatment steam gun Continuous fermentation train 16

17 Example Experimental Systems: High Throughput Analysis System 17

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19 Closing Thoughts We have limited options for powering transportation via sustainable resources Biofuels are only sustainable route to liquid transportation fuels for air travel, heavy vehicles, and long distance driving Cellulosic fuels offers significant environmental, economic, and strategic benefits Tremendous progress has been made in improving the biological processing of cellulosics so it is ready to be commercialized Most important challenge is to reduce the cost of releasing sugars from cellulosic biomass in combined operations of pretreatment and enzymatic hydrolysis 19

20 Acknowledgments Ford Motor Company The BioEnergy Science Center, a U.S. Department of Energy Bioenergy Research Center supported by the of Biological and Environmental Research Office in the DOE Office of Science DARPA Mascoma Corporation Mendel Biotechnology National Institute of Standards and Technology USDA National Research Initiative Competitive Grants Program US Department of Energy Office of the Biomass Program The University of Massachusetts, Amherst The University of California at Riverside UCR College of Engineering Center for Environmental Research and Technology 20

21 Questions??? 21