The wet gasification of biomass has now been demonstrated in a continuous-feed, fixed-bed catalytic reactor system at bench-scale with a solids separation system to protect the catalyst bed from poisoning and fouling. The short-term runs suggest a pathway to longer term operation. The inorganic components in the feedstocks were effectively removed by the solids separation system and prevented from poisoning and fouling or plugging the catalyst bed. Sulfur trapping was not as effective in these tests, but alternate trap materials are available. Aqueous effluents with low residual COD (as low as 100 ppm) and a product gas containing methane and carbon dioxide have been produced from fermentation stillage from corn ethanol production and wheat millfeed following starch extraction. These results suggest that continuous-flow processing of actual biomass feedstocks, which have mineral and sulfide containing components, can be accomplished without fouling or poisoning the catalyst bed. The product gas from this process is a clean methane-containing stream that should be useful for hydrogen production and other uses.
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