Effect of the Ni-to-CaO Ratio on Integrated CO2 Capture and Direct Methanation

Direct methanation in an integrated CO2 capture and utilization system has recently gained considerable attention as a promising approach owing to its simplified process and lower requirement of total thermal energy as compared to conventional CO2 capture and utilization techniques. This study formulated macroporous structured Ni/CaO catal-sorbents by controlling the Ni-to-CaO ratio. The influence of this ratio on the CO2 capture (capacity and kinetics) and direct methanation performances (productivity and kinetics) was evaluated at 500 °C. CO2 capture combined with direct methanation experiments revealed that 10Ni/CaO exhibited the best CO2 capture capacity, kinetics, and CH4 productivity with the thermal stability of Ni and CaO species.