International Journal of Energy Research, Vol.45, No.3, 4098-4111, 2021
CO2 absorption into aqueous solutions of N-methyl-1,3-propane-diamine and its blends with N,N-diethylethanolamine-New kinetic data
The rates of CO2 absorption into aqueous solutions of N-methyl-1,3-propane-diamine (MAPA) and its mixture with N,N-diethylethanolamine (DEEA) have been studied in a stirred cell reactor under the fast reaction regime. The experiments were carried out for 0.2 M MAPA and DEEA + MAPA blends with a total amine concentration of 2 M over the temperature range of 303 to 333 K. It was found that relatively low concentrations of MAPA ranging from 0.05 to 0.2 M in DEEA solutions significantly accelerated the rate of CO2 absorption. Kinetic data for the reactions of CO2 with MAPA were not available in the literature within the present experimental range. Based on the experiments in DEEA+MAPA blends, the pseudo-first-order rate constants were calculated and analyzed together in one global analysis. Using the termolecular mechanism, the specific kinetic rate constants for the reactions between CO2 and MAPA were determined and correlated by the Arrhenius equation. Finally, a comparison of the efficiency of the studied MAPA with other fast amines including N-ethylethanolamine, 1,6-hexamethyldiamine, N-[2-aminoethyl] ethanolamine), and piperazine confirmed its potential as an excellent rate promoter for CO2 absorption.