Development of Cellulosic Biofuels Chris Somerville Energy Biosciences Institute UC Berkeley, LBL, University of Illinois
Potential of carbon-free energy sources TW 1000000 100000 10000 1000 100 10 1 0.1 Hydro Tides & currents Wind Geothermal Solar Current use? Nuclear From: Basic Research Needs for Solar Energy Utilization, DOE 2005
Mixed Alcohols Summary of Syngas-Liquids Processes Alkali-doped i-c 4 NH 3 Isosynthesis ThO 2 or ZrO 2 N 2 over Fe/FeO H 2 O WGS Purify (K 2 O, Al 2 O 3, CaO) Waxes Diesel Fischer-Tropsch Fe, Co, Ru Syngas Cu/ZnO Methanol CO + H 2 ZnO/Cr 2 O 3 Cu/ZnO; Cu/ZnO/Al 2 O 3 CuO/CoO/Al 2 O 3 MoS 2 Oxosynthesis HCo(CO) 4 HCo(CO) 3 P(Bu 3 ) Rh(CO)(PPh 3 ) 3 H 2 Olefins Gasoline Formaldehyde Ag Co, Rh Aldehydes Alcohols Ethanol MTBE Al 2 O 3 DME Acetic Acid carbonylation CH OH + CO 3 Co, Rh, Ni isobutylene acidic ion exchange zeolites MTO MTG M100 M85 DMFC Olefins Gasoline Direct Use homologation Co bioconversion Richard Bain, NREL
Conversion of sugar to alkanes Huber et al., (2005) Science 308,1446
Perspective Economists are helpful for evaluating the feasibility and consequences of alternative scenarios Social scientists are helpful for flagging social issues that can block adoption of technology
World Land Use Nonarable 34.4% Other crops 6.9% Forest & Savannah 30.5% Cereal 4.6% Pasture & Range 23.7% AMBIO 23,198 (Total Land surface 13,000 M Ha)
Thinking beyond tofu Emissions from meat production equivalent to all transportation fuels Cattle are major threats to many ecologically sensitive regions Ruminants are a very inefficient source of nutrition Can we create acceptable alternatives?
Combustion of biomass can provide carbon neutral energy Sunlight CO 2 Photosynthesis Combustion Polysaccharides (Storage) Work
Combustion of biomass can provide carbon neutral energy Sunlight CO 2 Tilling Land conversion Fertilizer Transportation Processing CO 2 Photosynthesis Combustion Biomass Work But it depends on how the biomass is produced and processed
Problems with corn, soy, rapeseed for biofuels Annual crop production leads to soil erosion, fertilizer runoff, loss of soil carbon, nitrous oxide emissions, pesticide effects Weakly positive for GHG emissions Increased feed and food price May stimulate production of food on ecologically sensitive acres (indirect effects)
>>A billion acres of agricultural land have been abandoned Campbell et al., Env. Sci. Technol. (2008) ASAP Article, 10.1021/es800052w
Limited potential of biodiesel O CH 3 O Biodiesel 160 140 Billion gallons 120 100 80 60 40 20 0 Current biodiesel Capacity US Diesel US Fuel 65 biodiesel companies in operation, 50 in construction 2006
Oil potato, oil cane, oilfalfa Accumulate terpenes or alkanes in vegetative tissues Increased solar efficiency Cold press tissue in field Environmental benefits Transportation and storage costs decrease Costs of conversion to fuels minimal Engineering costs greatly decrease
Knowledge of developmental mechanisms will create entirely new opportunities for producing biomaterials Ogas et al., Science 277,91
Renewable Fuel Standard (Energy Independence and Security Act of 2007) 40 35 30 25 Biodiesel General Advanced Cellulosic Advanced Conventional Previous RFS Advanced 20 15 10 5 0 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 Year Biofuel Volume (billion gallons)
US Biomass inventory = 1.3 billion tons 26 B gals ~ Corn stover 19.9% Wheat straw 6.1% Soy 6.2% Crop residues 7.6% Grains 5.2% Perennial crops 35.2% Forest 12.8% Manure 4.1% Urban waste 2.9% From: Billion ton Vision, DOE & USDA 2005
Potential bioenergy crops tested in the US From Lewandowski et al., Biomass & Bioenergy 25,335
>1% yield is feasible Yield of 26.5 tons/acre observed by Young & colleagues in Illinois, without irrigation Courtesy of Steve Long et al
Harvesting Miscanthus http://bioenergy.ornl.gov/gallery/index.html
Perennials have little or no erosion Corn Soybeans Perennial herbaceous Short rotation wood 0 10 20 30 40 50 Tonnes/HA/y of soil loss From Oliveira et al in: Jones and Walsh (eds) Miscanthus for Energy and Fibre, 2001
Response of Miscanthus to nitrogen fertilizer 20 15 N0 N60 N120 Yield (t/ha) 10 5 0 93 94 95 96 97 98 99 0 1 2 3 4 5 6 Year Christian, Riche & Yates Ind. Crops Prod. (2008)
Some research topics in crop production Self-incompatibility Breeding challenging Biotic and abiotic stress A lot of dry or saline land available Identification of useful species Non-invasive, high productivity, low input Identification of useful variation Nutrient recycling and efficiency Nitrogen fixation
The Future http://genomicsgtl.energy.gov/biofuels/index.shtml