Theoretical investigation on CO2 absorption into DEAB solution using hollow fiber membrane contactors

Abstract

4-Diethylamino-2-butanol (DEAB) is a novel amino alcohol, which has been synthesized to incorporate the advantages of amine blends such as low regeneration energy as well as high CO2 pick up. In this study, the absorption of carbon dioxide by monoethanolamine (MEA), diethanolamine (DEA), methyldiethanolamine (MDEA) and DEAB solutions was compared theoretically in a hollow fiber membrane contactor. A numerical analysis was performed to solve the applied partial differential equations for the liquid, gas and membrane phases simultaneously. The model results were validated using the available experimental data in the literature for MEA, DEA and MDEA. The effects of different operating conditions including DEAB concentration, system temperature, liquid and gas velocities and CO2 partial pressure on the removal behavior of CO2 were investigated. The simulation results indicated that the CO2 absorption flux into DEAB solution was lower than MEA solution, however much higher than MDEA solution in all range of CO2 partial pressures. DEAB had almost the same absorption flux compared to DEA solution at low partial pressures of CO2, and a better performance at higher CO2 partial pressures. Increasing the system temperature, DEAB concentration, gas and liquid flow rates enhanced the absorption flux.