CO2 Reduction in Structured Ni/Mayenite Catalytic System: A Methanation Test by Means of a Pre-Industrial Scaled Chemical Pilot Plant

The performance of a Mayenite-supported nickel-based catalyst were investigated by using an in-house-designed, assembled and set-up chemical pilot plant, which was developed to provide experimental insights relevant to industrial scale up. In particular, the proposed heterogeneous catalytic system was structured in mm-sized spheres and tested in a large-scale experiment, in a fixed-bed reactor for the CO2 methanation process, and the results were compared with the output achieved with a Ni/alumina catalyst produced by an analogous route as the benchmark. The obtained findings highlighted the effective potential of the Mayenite structure supporting metallic active sites in promoting CO2 reduction under the selected operating conditions (450 °C, 4 bar), along with long-term stability and high CH4 selectivity. Moreover, the available experimental equipment was optimized to achieve accurate estimations of amounts of reaction by-product , as confirmed by the optimal agreement with the mass balance retrieved from the measured gaseous outlet composition. Such an achievement, notable for a large-scale chemical plant, plays a capital role in terms of industrial applications due to the critical impact of residual carbon and water in establishing the viability of innovative catalyst systems for the CO2 recycling process.