Potential Application of Alkaline Metal Nitrate-Promoted Magnesium-Based Materials in the Integrated CO2 Capture and Methanation Process

An integrated CO 2 capture and methanation process with regenerable H 2 is a promising approach to mitigate anthropogenic CO 2 emissions. In this integrated process, the development of efficient adsorbents and catalysts is very critical. Here, NaNO 3 -promoted MgO adsorbents are prepared and shaped into ∼1.5 mm particles for CO 2 capture, and the potential application of NaNO 3 -MgO adsorbents in the integrated CO 2 capture and methanation process is evaluated through experiments. Experimental demonstration is performed in the combined adsorbent/catalyst packed column, where CO 2 adsorbents are prepared with 10 mol % NaNO 3 -promoted MgO and catalysts are prepared with 20 wt % Ni loaded on γ-Al 2 O 3 . The effects of the flowrate of 50% CO 2 /N 2 feed gas and the flowrate of regenerable H 2 on the CO 2 capture and methanation performance are investigated through experiments done in the packed column with 40 g of NaNO 3 -MgO granules and 30 g of Ni-Al 2 O 3 catalysts. The CO 2 recovery rate, CO 2 adsorption amount, CO 2 conversion rate, and CH 4 yield and selectivity will be evaluated based on the experimental results, and the efficiency and feasibility of the integrated CO 2 capture and methanation in the combined NaNO 3 -MgO adsorbent/Ni-Al 2 O 3 catalyst packed column will be assessed.