Production costs of liquid fuels from biomass

This project was undertaken to provide a consistent and thorough review of the full range of processes for producing liquid fuels from biomass to compare both alternative technologies and processes within those technologies in order to identify the most promising opportunities that deserve closer attention. Thermochemical conversion includes both indirect liquefaction through gasification, and direct liquefaction through pyrolysis and liquefaction in pressurized solvents. Biochemical conversion is based on a different set of feedstocks. Both acid and enzyme hydrolysis are included followed by fermentation. The liquid products considered include gasoline and diesel hydrocarbons and conventional alcohol fuels of methanol and ethanol. Results are given both as absolute fuel costs and as a comparison of estimated cost to market price. In terms of absolute fuel costs, thermochemical conversion offers the lowest cost products, with the least complex processes generally having an advantage. Biochemical routes are the least attractive. The most attractive processes from comparing production costs to product values are generally the alcohol fuels which enjoy a higher market value. (author)