23-03-2012, 02:40 PM
Bioethanol: A Renewable Transportation Fuel from Biomass
renewable_fuel.pdf (Size: 696 KB / Downloads: 110)
What is bioethanol?
•Fuel ethanol made from non food biomass sources•Requires “new” technology:–To break down (hydrolyze) cellulose and hemicellulose to sugar –To ferment “unusual” sugars in biomass
Potential Midterm U.S. Biomass Supply
•42 million acres (10% of total cropland) switches to bioenergy crops, includes 13 million acres of CRP land
•181 million dry tons of switchgrass per year at $50 per ton or less
Life Cycle Assessment—a framework for making choices that support a sustainable
society
•“Cradle to grave”
•Accounts for all flows to and from the environment
–Air, water and solid waste emissions
–Energy resources
–Other primary resources extracted from the environment
•Basis for technology and policy decisions by business and government
Biomass Pretreatment
Chemical partial hydrolysis prior to enzyme hydrolysis
•Reactor design is complex!–Continuous processing–High solids, erosive, corrosive–High temperature, pressure–Heterogeneous catalysis of complex substrate–Many simultaneous reactions•Tools for improving pretreatment –Multiple reactor sizes and configurations–Impeccable analytical process chemistry–Kinetic and molecular modeling–Computational fluid dynamics