Combined capture and reduction of CO₂ to methanol using a dual-bed packed reactor

Abstract

Recently, carbon capture and reduction (CCR) technology has gained interest to directly convert CO₂ to value-added products without requiring purification of CO₂ and its subsequent transportation. CCR to methanol in one dual function material (DFM) poses mechanistic and kinetic challenges. To counteract this, a process combining Na/Al₂O₃ as a capture component and Cu/ZnO/Al₂O₃ (CZA) as methanol synthesis catalyst was developed to allow CCR to methanol. With a 5 vol% CO₂ flow for capture and subsequent H₂ stream combined with a temperature swing, a methanol selectivity of 26 % was achieved at 9 bar. Further investigation found that Na/Al₂O₃ significantly increased methanol yield, while a stacked configuration of Na/Al₂O₃ followed by CZA significantly outperformed a mixed configuration of the two catalysts. With further investigation of operation at higher pressure and surface mechanism, an effective CCR to methanol process using two affordable yet readily available catalysts can be realized.