Gasification of bean curd refuse with carbon supported noble metal catalysts in supercritical water

Gasification of bean curd refuse was examined in the presence of carbon supported noble metal catalysts in sub- and supercritical water from 473 K to 673 K. The activity of catalyst was in the order of Ru/C >> Rh/C > Pt/C > Pd/C. The effect of reaction condition with Ru/C catalyst was examined in detail. In the presence of catalyst and water, bean curd refuse decomposed to intermediates and then intermediates were gasified. The main gas products were methane and carbon dioxide. The sum of the yield of gases significantly increased with increase in water density at 673 K. The highest total gas yield in a carbon basis was 76% at 673 K and 0.5 g/cm(3) of water density. The yield of gases increased with increasing temperature especially above 623 K at initial water density of 0.5 g/cm(3). The experiments changing temperature profile revealed that rapid heating was effective for the gasification because rapid heating probably prevented the formation of heavier components in low temperature region. (C) 2010 Published by Elsevier Ltd.