Energy Applications, New Products, New Risks
Sabrina Spatari, Ph.D., P.Eng Associate Professor, Drexel University Civil, Architectural, and Environmental Engineering
November 5, 2015 Philadelphia, PA
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Diversifying Transportation Energy Supply • Energy independence or energy diversity? – U.S. policy context for low carbon fuels – Motivation for developing “drop-in fuels”
• The role of biomass • Life cycle approaches • Major Challenges
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The Tar Sands Disaster Homer-Dixon, NYT Op-ed, March 31, 2013
Oil sands: 1J to process = 6 J SCO Conventional oil: 1J to process = 15 J crude oil
.. stopping Keystone XL would be a major step toward stopping large-scale environmental destruction, the distortion of Canada’s economy and the erosion of its democracy.
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Avenues for Decarbonizing Transportation • Biomass-to-biofuels, an avenue for decarbonizing transportation energy at large scale – the transportation “wedge” Pacala and Socolow, Science, 2004. 305: 968-972
• “All biomass is local” – Bruce Dale • Renewable, domestic, low carbon, BUT − Feedstocks today: grain/corn (ethanol); lignocellulose emerging – Mingles energy with food markets – Direct and indirect CO2 from land use change (LUC) – Other sustainability risks: water, biodiversity, food security – Will transform rural communities (socio-economic effects)
• Need for sustainable feedstock development: 4
Policy Context: • Since 2004, low carbon and renewable fuel policies in development around the world • LCFS (California, North-east states, Canada), RFS (US), Europe (EC) • Reduce GHGs relative to baseline gasoline ~93 gCO2e/MJ • Life cycle assessment (LCA)-based policy
• Biofuels and policy context for decarbonizing transportation energy supply • Energy Independence and Security Act (EISA) • Incentives to develop “drop-in fuels” • Incentives to develop lignocellulosic energy products that avoid major sustainability risks: Better biofuels 5
LCFS/RFS: Fuel Cycle Model Vehicle use
Fuel cycle
Feedstock Production
Ethanol Conversion
- Fertilizer - Herbicides - Harvesting operations -CO2/N2O flux
Feedstocks: - corn
+ Indirect consequences
Vehicle Operation
- Chemicals, Enzymes, - Blending with gasoline -Nutrients - Vehicle operation -Co-products: CO2, protein meal, hulls (energy recovery) -Denaturant (2% gasoline) Technologies: -Dry grind process -Sugar generation -Fermentation -co-product crediting
Land Use Change (LUC)
Vehicle: -Ethanol-fueled vehicle (E92) -Compare with baseline -gasoline vehicle (93 g CO2e/MJ)
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The Whole Transportation Story
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Chester and Horvath Environmental Research Letters 2009, 4, (2), 024008.
Policy Context: • Since 2004, low carbon and renewable fuel policies in development around the world • LCFS (California, North-east states, Canada), RFS (US), Europe (EC) • Reduce GHGs relative to baseline gasoline ~93 gCO2e/MJ • Life cycle assessment (LCA)-based policy
• Incentives to develop lignocellulosic energy products that avoid major sustainability risks: Better biofuels • Biofuels and policy context for decarbonizing transportation energy supply • Energy Independence and Security Act (EISA) • Incentives to develop “drop-in fuels” 8
Diverse Biofuel Platforms: LCA & TEA Life cycle environmental and techno-economic model development: • Aspen Plus (TEA), Simapro/Gabi (LCA) and GIS (Spatial) modeling: – Feedstock production, collection, transport – Material/energy balance basis (feedstock conversion);
• Integration with experimental research: – Thermochemical bio-oil blendstock development • In-situ and ex-situ catalytic bio-oil upgrading • catalytic pyrolysis products
– Biochemical conversion – Waste from fats, oils, greases, wastewater scum 9
Drop-in Blendstock Conversion Model Enzyme Production Feedstock: Cellulose Hemicellulose Lignin
Cellulose* Xylose Arabinose Mannose Galactose
Lignin
Hydrolysis & Aerobic Fermentation
Steam & Electricity Energy Recovery
FFAs Water
FAAs DeOx
Lignin Separation & Wastewater Treatment
Lignin & biogas Syrup & solids
Centrifuge, Vacuum drying
Enzymes
Pretreatment
Blendstock 0% O Electricity Finished Products 10
* Pre-treated cellulose
Corn Stover and Switchgrass - Bioethanol Life Cycle GHG emission profiles GHG emissions g CO2e MJ-1
200 150
Switchgrass
Corn Stover
100 Gasoline 93 g CO2e/MJ
50 0 -50 -100
w/o LUC CO2
w/ LUC CO2
-150 -200 DA
AFEX
DA
AFEX
DA
AFEX
DA = dilute acid pretreatment followed by simultaneous saccharification and cofermentation (SSCF) AFEX = ammonia fiber explosion pretreatment followed by SSCF 11
Spatari and MacLean (2010), Environ. Sci. Technol. 44: 8773-8780
The Nonsense of Biofuels! Michel, H., 2012* Low overall conversion of sunlight to terrestrial biomass <1%
Higher land use efficiency with PV technology**
* Angew. Chem. Int. Ed. 51, 2516 – 2518 **Geyer, R. et al., Environ. Sci. Technol. 2013, 47, (2), 1170-1176.
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Better, Biomass, Biofuels, valueadded co-products AND integrated systems • Value-added products (lubricants, chemicals) need to be co-produced to improve the economics of biofuels • Integrate renewable energy technology (wind and solar) with liquid/solid energy storage
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