Study of CO₂ Absorption into Phase Change Solvents MAPA and DEEA

This work provides new data for carbon dioxide (CO 2 ) absorption into phase change solvent systems consisting of an aqueous solution of 2-(diethylamino)ethanol (DEEA) and 3-(methylamino)propylamine (MAPA). The variables related to CO 2 absorption are studied and a Lewis cell type apparatus is taken into use. The latter was first validated with experiments of CO 2 absorption into aqueous methyl diethanolamine (MDEA) solutions. Experiments are carried out for the determination of apparent kinetic absorption constant and absorption rate of CO 2 for aqueous DEEA/MAPA mixtures. The determined kinetic constants (0.008–0.007 mol·(m 3 ·s) −1 for MAPA/DEEA between 308 and 318 K and 0.0184–0.0022 m 3 ·(mol·s) −1 for MDEA between 296 and 318 K) are compared to the literature where available. The phenomena related to phase change solvent absorption are carefully studied. A relation between total CO 2 loading and absorption rate is observed, and reasons behind the dependency and the phenomena are analyzed.