Organic decomposition in supercritical water by an aid of ruthenium(IV) oxide as a catalyst - Exploitation of biomass resources for hydrogen production

The present paper deals with the production of hydrogen from biomass in supercritical water in the presence of ruthenium(IV) dioxide, RuO2, as a catalyst. Experiments were carried out to gasify cellulose and lignin, the mixtures of cellulose and lignin for the simulation of biomass, and finally actual biomass such as pulp, waste paper and paper sludge. Each sample was loaded in a reaction vessel under argon atmosphere at 450 degrees C and around 44 MPa for 120 min. The gas produced was quantitatively analyzed by an on-line gas chromatography. It was found that RuO2 enhanced the decomposition ratios for cellulose and pulp, but not for lignin and lignin containing compounds. Obviously, lignin deactivated the catalytic effect of RuO2. The hydrogen production ratios in gasses produced were 15.0% from cellulose, 14.1% from pulp, 21.0% from the mixture of cellulose and lignin, 16% from waste paper and 27% from and paper sludge, respectively. We have concluded that the present method would be feasible for the production of hydrogen. (C) 2005 Published by Elsevier Ltd.