CO2 absorption: solubility of CO2 in 2-amino-2-methyl-1-propanol solvent promoted by piperazine and monoethanolamine blends

Abstract

This research work investigates the solubility data of carbon dioxide (CO2) in a novel ternary blend of aqueous 2-amino-2-methyl-l-propanol (AMP) promoted by piperazine (PZ) and monoethanolamine (MEA) blends have been experimentally analysed at 20℃, 40℃, and 60℃ at CO2 partial pressures between 2 kPa and 100 kPa. At 40 ℃ and 93.93 kPa CO2 partial pressure, the concentrations of PZ and MEA promoters were varied between 0.5 M - 1 M and 2 M - 4 M, respectively, while the AMP concentration was kept at 2 M. The various concentrations of the ternary blend possessed superiority in both the equilibrium CO2 loading (6.9 % to 19 %) and absorption working capacity (13.8 % to 48.3 %) compared to the conventional 5 M MEA. The effects of MEA and PZ concentrations, and H2O- Amine molar ratio in terms of H2O/PZ was also studied, and the solvent combination of 2 M AMP - 0.5 M PZ - 3 M MEA was selected for further equilibrium CO2 loading analysis considering its very minimal potential of forming solid precipitates. The results were reported as a function of CO2 partial pressures at the investigated temperatures. In addition, the energy penalty during regeneration was predicted using a validated ProMax® 3.2 CO2 capture plant simulation. The simulation results indicated that the ternary blend solutions higher than 5 M had energy reductions between 5.3 % - 26.3 % compared to 5 M MEA (at the same condition).