A whole lignocellulosic biomass-to-ethanol biorefinery was designed and modeled. The overall process efficiency and economic performance of the biorefinery to manufacture liquid fuels from lignocelluloses was studied. The effects of biomass species and chemical composition on the overall process efficiency and economic performance to manufacture ethanol from lignocellulose was studied. The amount of holocellulose of the feedstock was in the same order as the ethanol production, and the ethanol production was largely linear with holocellulose composition of various species. However, the relationship between excess electricity generated and non-holocellulose combustible component was nonlinear. Aspen wood had the lowest amount of waste effluent, switchgrass the highest, hybrid poplar and corn stover were in between. All biomass species could be used to produce ethanol at reasonable cost, with aspen showing the lowest cost and the lowest waste effluents than the other biomass species. This is an abstract of a paper presented at the 2006 AIChE Annual Meeting (San Francisco, CA 11/12-17/2006).