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 CH₄reforming 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, H₂and 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.