Wednesday, May 1, 2013: 8:50 AM
Grand Ballroom II, Ballroom Level
Infrastructure compatible hydrocarbon biofuel that is proposed to qualify as renewable transportation fuel under the US Energy Independence and Security Act (EISA) and Renewable Fuel Standard (RFS2) is evaluated. The process uses hybrid poplar for feedstock, which undergoes dilute acid pretreatment and enzymatic hydrolysis. Sugars are fermented to acetic acid, which undergoes conversion to ethyl acetate, ethanol, ethylene, and finally a saturated hydrocarbon end product suitable for blending with jet fuel. A lignin rich stream that is not fermented may either be burned for steam and electricity production, or gasified. During the biofuel production process, hydrogen gas is required in two unit operations and may be obtained by various methods including lignin gasification. In order to meet a required 60% reduction in greenhouse gasses compared to conventional fuels, life cycle analysis work on the combined biofuel and hydrogen production methods is performed. Next, both technical and economic aspects of the biorefinery are analyzed, with a range of hydrogen sources considered. These include steam reforming of natural gas, gasification of lignin, and electrolysis of water using seasonal excess hydroelectric capacity in the Pacific Northwest. Rigorous chemical engineering processing software is used to model the conversion of biofuel. Results of this model are used in a spreadsheet developed to model economic tendencies of the biorefinery including both capital and operating expenditures. Overall results of the techno-economic analysis are incorporated into life cycle assessment work to estimate life cycle greenhouse gas emissions from the various hydrogen production scenarios.