Modeling Biomass Conversion to Transportation Fuels Jacob Miller Advisor: Dr. Eric Larson

Outline What is biomass? Why is it useful? What is bioconversion? What is biomass made of? Manufacturing process Model creation: Mass, energy, and carbon balances Economic modeling, carbon and energy credits Final cost estimates

What is biomass? Yes No Switchgrass Corn Stover Corn Soybeans Inedible plant matter

Bioconversion Rubin,

Components of Biomass What we care about: Cellulose, lignin, hemicellulose Alonso et al Enzymatic hydrolysis, bioconversion to fuels Pretreatment, bioconversion to fuels Burned for electricity

3 Core Processes Pretreatment: Separate hemicellulose and lignin from cellulose, depolymerize hemicellulose (in some cases) Common methods: dilute acid, steam, ammonia Hydrolysis: break cellulose up into individual glucose monomers Method: enzymes (biological catalysts) Bioconversion: converts sugars to fuel molecules Common example: fermentation of glucose to ethanol

Model Basis: NREL Model Davis et al Process units altered slightly in various scenarios

Model Creation: Mass, Energy, and Carbon Balances Mass flows, kg/hr =Process CO 2 outlets

Final Cost Estimates Sample MFSP: Minimum fuel selling price Takeaway: cellulosic biofuels won’t be economical without high CO 2 taxes Plant Configurations

Acknowledgements Princeton Environmental Institute Dr. Eric Larson, Dr. Thomas Kreutz, Dr. Robert Williams, Dr. Hans Meerman, Maurizio Spinelli

Questions?

Economic Modeling, Carbon and Energy Credits Discounted Cash Flow Analysis External power source/replacement: Natural gas combined cycle plant CO 2 tax: $0-$100/ton

Components of Biomass Plant % Dry Mass Cellulose % Dry Mass Hemicellulose % Dry Mass Lignin % Dry Mass Other Sugarcane bagasse Switchgrass Corn stover Rezende et al Godin et al Kumar et al. 2009

Carbon Capture Integration Rectisol Less expensive ($1s million capital costs) Can only capture CO 2 from pressurized sources Amine Solvent More expensive ($100s million capital costs) Can capture CO 2 from any emissions source (ex: biomass generator)