Rational design of aqueous tertiary amine solvent for integrated CO2 capture and hydrogenation

Abstract

Several tertiary amine solutions with different structures were tested in the integrated CO2 capture and hydrogenation process in the presence of heterogeneous Pd/NAC catalysts. The tertiary amines of 3-dimethylamino-1,2-propanediol (3DMA-1,2-PD) and 3-diethylamino-1,2-propanedio (3DEA-1,2-PD) with high CO2 absorption capacity and high formate yield were selected as suitable candidates as CO2 capture and hydrogenation solvents. Under mild reaction conditions, a high formate yield of 68% was achieved when using 1 M 3DMA-1,2-PD solution with CO2 loading of 0.5 mol amine/mol CO2. In addition, the physico-chemical properties of the Pd/NAC catalysts were examined and the reaction mechanism of CO2 absorption and hydrogenation in the presence of Pd/NAC was proposed.