Transportation fuel from cellulosic biomass: a comparative assessment of ethanol and methanol options

Future sources of renewable fuel energy will be needed to supplement or displace petroleum. Biomass can be converted to ethanol or methanol, both having good properties as a motor fuel, but requiring distinctly different production technologies. Those technologies are compared in terms of production cost, potential for petroleum displacement and effectiveness for management of greenhouse gas emissions. Supply curves that relate the crop price to the national biomass production potential are crucial to the comparison. The higher delivered cost of biomass that would be acceptable as feedstock for methanol production, plus the increased conversion efficiency and lower production cost that can be obtained by use of natural gas as a co-feedstock, are major factors favouring methanol. The overall net carbon dioxide emission reduction and petroleum-displacement potential of methanol produced in a single process from biomass and natural gas in the United States are nine times those of two separate processes that would produce ethanol. from the same amount of biomass and methanol from the same amount of natural gas.