Biomass gasification product gas consists mainly of CO, H₂, CO₂, H₂O, N₂, and hydrocarbons. Minor components of the syngas include tars, sulfur and nitrogen oxides, alkali metals, and particulates. These minor components of the syngas potentially threaten the successful application of downstream fuel conversion steps. Comprehensive cleanup and conditioning of the raw biomass gasification product gas is required to produce a “clean” syngas that be can converted into biofuels. A number of high temperature, high pressure processes, commonly referred to as Fischer-Tropsch synthesis have been developed to produce gasoline, diesel, or mixed alcohol fuel.

This presentation highlights thermochemical ethanol production via biomass gasification/mixed alcohol fuel synthesis. Research activities at NREL include gasification fundamentals and process modeling, catalyst development, integrated gas cleanup and conditioning, and mixed alcohol synthesis. Conceptual designs and techno-economic models have been developed for a biomass gasification process with thermochemical ethanol production via mixed alcohols synthesis to determine how overcoming associated technical barriers contribute to reductions in finished ethanol costs.