Adsorption and Methanation of Flue Gas CO2 with Dual Functional Catalytic Materials: A Parametric Study

Conventional carbon capture and sequestration (CCS) in aqueous alkanolamine solutions is an energy-intensive process for power plant flue gas CO, treatment. We report a laboratory parametric study on the utilization of CO, from simulated natural gas postcombustion effluent by cyclic adsorption and methanation using a single dual functional material (DFM). The DFM is composed of nanodispersed CaO and Ru metal supported on an gamma-Al2O3 carrier (5% Ru, 10% CaO/Al2O3), respectively functioning as the CO2 adsorbent and methanation catalyst. The stored H-2 used for methanation is assumed to be produced by water electrolysis using excess alternative wind or solar energy. The effects of DFM preparation methods, Al2O3 carrier materials (with different shapes and properties), and adsorption and methanation conditions (feed compositions, flow rates, and reaction temperatures) were examined. The DFM samples, prepared using chloride precursor salts, showed stable performance under cyclic operating conditions. Reaction conditions were explored for the optimized CO2 utilization efficiency.