The Comparison of CO2 Absorption Performance between DEAPA (3-Diethylaminopropylamine) and Blends of MEA-MDEA

Abstract

Amineaffects the absorption performance and energy cost forCO2 capture with chemical solvents. To searchthe desirable amine solvents with higher absorption rate andlower energy penalty would be a challenge task. In the presented study, the CO2 absorption performance for3-(Diethylamino)propylamine (DEAPA), a diamine that contains one primary and one tertiary amine in the same molecule, is investigated and compared with the blended amine system of Monoethanolamine and Methyldiethanolamine (MEA-MDEA), a mixed amine solvent of equal mole of primary and tertiary amine. The absorption rate and CO2 equilibrium solubility are tested for DEAPA (2M) and MEA-MDEA (4M,mole ratio=1:1), and the MEA is served as the base case. The experimental results show that the intramolecular tertiary amino group of DEAPA can promote the CO2 absorption rate of the intramolecular primary amino group and enhance its CO2 absorption capacity. The results from13C NMR technique also indicate that the intermolecular tertiary amine in MEA-MDEA system ismore favored to promote the primary amine in the blend to form the bicarbonate at an earlier CO2 equivalent loading stage and produce less carbamate than that of the intramolecular tertiary amino group of DEAPA to its primary amino group.