Effect of Sulfur on Catalytic Gasification of Biomass in Supercritical Water

Abstract

Poisoning of ruthenium catalyst by sulfur during gasification of lignin in supercritical water was examined. In the absence of sulfur, lignin was gasified to methane, carbon dioxide and hydrogen completely. In the presence of sulfur, lignin could be gasified, however, the rate of lignin gasification decreased. The gaseous product yield increased with increasing water density over the carbon supported ruthenium catalyst. The formation of low-molecular-weight fragments was enhanced with increasing water density and then these fragments were decomposed to gases over the ruthenium surface. In addition, the possibility which the high-density water inhibited the adsorption of sulfur atoms to active sites was indicated.