Deactivation characteristics of Ni and Ru catalysts in tar steam reforming

Tar formation resulting during lignocellulosic biomass gasification is a major impediment to utilizing biomass energy sources, in that it blocks and fouls the processing equipment; as such, any tar present in the produced syngas much be effectively removed. This study analyzes the ability of commercially available Ni and Ru based CH4 reforming catalysts to effect tar removal and compares deactivation characteristics. Toluene was used as the model biomass tar at concentrations of 30 and 100 g/Nm3. Several additional parameters were also tested, including reaction temperatures (400-800 °C), space velocities (5000-30,000 h−1), and the steam/toluene ratios (2-20). The variation of toluene conversion and product gas composition with reaction conditions was analyzed. Overall, H2 and CO production were favored by the Ru catalyst and generally increased with temperature. Conversion also increased with temperature, with conversions higher than 90% obtained at 800 °C.