Deactivation of Ni catalyst in three-phase CO2 methanation

Abstract

In three-phase CO₂ methanation dibenzyl toluene is used as the liquid phase in a slurry bubble column reactor. At reactor temperatures (T_R) higher than 260 °C deactivation of the Ni/SiO₂ catalyst was observed. After deactivation for 120 h at T_R = 320 °C, stationary operation is possible with a loss of catalytic activity of ≈50%. Based on experimental results, it can be stated that deactivation is caused by decomposition of dibenzyl toluene at high reactor temperature, resulting in carbon deposition on the catalyst surface.