Improvement of the activity of CO2 methanation in a hybrid plasma-catalytic process in varying catalyst particle size or under pressure

Abstract Ceria zirconia Ni-based catalysts with different particle sizes varying from 30 to 500 μm were prepared, characterized by SEM, XRD, BET, TPR and TPD, and then tested in CO2 methanation in a thermal-catalysis system and a plasma-catalytic system. Different experimental parameters such as chemical and physical ones were also studied. The influence of catalyst size was first studied. It was found that catalyst presenting bigger particle size (grain size) led to higher CO2 conversion in both processes due to a smaller metallic Ni particle size, the less gas maldistribution and better plasma homogeneity. Moreover, a pressure-drop was created in the reactor to investigate the influence of pressure on the plasma process. It should be noted that by increasing the pressure drop of the reactor in the plasma-catalytic process, a slight increase of CO2 conversion was observed while the plasma power decreased by 30%.