Toluene Decomposition in the Presence of Hydrogen on Tungsten-Based Catalysts

Removal of NH3, tars, and H2S from biomass gasification gas represents a significant step in the commercial use of biomass gasification as a source of hydrogen, syngas, and electricity. This paper reports the results of an investigation into the use of W-based catalysts [tungsten carbide (WC), tungstated zirconia (WZ), and platinum supported on tungstated zirconia (PtWZ)] for catalytic tar removal. In this study, toluene was used as a model compound for tars. In the case of WZ, the effect of calcination temperature on the activity of toluene decomposition was also investigated. The toluene decomposition reaction was conducted at 1 atm, in the temperature range of 300−800 °C, and in the presence of 10% H2. CH4 and benzene were the only detectable products of toluene decomposition on all the catalysts. Incorporation of 5 wt % Pt with WZ was found to give the most effective catalyst considering initial rates of product formation. WC, WZ, and PtWZ each showed an initial partial deactivation for both CH4 and b...