Nickel catalyst in coupled plasma-catalytic system for tar removal

Tar formation is a significant issue during biomass gasification. Catalytic removal of tars with the use of nickel catalyst allows to obtain high conversion rate but coke formation on catalysts surface lead to its deactivation. Toluene decomposition as a tar imitator was studied in gliding discharge plasma-catalytic system with the use of 5%, 10% and 15% by weight Ni and NiO catalyst on Al₂O₃ (α-Al₂O₃) and Peshiney (γ-Al₂O₃) carrier in gas composition similar to the gas after biomass pyrolysis. The optimal concentration of nickel was identified to be 10% by weight on Al₂O₃. It was stable in all studied initial toluene concentrations, discharge power while C₇H₈ conversion rate remained high – up to 82%. During the process, nickel catalysts were deactivated by sooth formation on the surface. On catalysts surface, toluene decomposition products were identified including benzyl alcohol and 3-hexen-2-one.