Catalytic hydrothermal gasification of biomass

A recent development in biomass gasification is the use of a pressurized water-processing environment to avoid drying of the biomass. This paper reviews the research undertaken developing this new option for biomass gasification. This review does not cover wet oxidation or near-atmospheric-pressure steam-gasification of biomass. Laboratory research on hydrothermal gasification of biomass focusing on the use of catalysts is reviewed here, and a companion review focuses on non-catalytic processing. Research includes liquid-phase, subcritical processing as well as supercritical water processing. The use of heterogeneous catalysts in such a system allows effective operation at lower temperatures, and the issues around the use of catalysts are presented. This review attempts to show the potential of this new processing concept by comparing the various options under development and the results of the research. (C) 2008 Society of Chemical Industry and John Wiley & Sons, Ltd