CO2 absorption using benzylamine as absorbent and promoter in a hollow fiber membrane contactor: A numerical study

Abstract

Benzylamine (BZA) is a novel amine that indicates a promising potential for CO2 absorption. In this work, a mathematical model has been presented to investigate the CO2 absorption using aqueous BZA compared to aqueous monoethanolamine (MEA), diethanolamine (DEA), and 4-diethylamino-2-butanol (DEAB) in a hollow fiber membrane contactor (HFMC). Several factors such as CO2 partial pressure, amine concentration, gas velocity, liquid velocity, temperature, wettability, and mass transfer resistance of phases have been studied. According to the results, increment in the amine concentration, CO2 partial pressure, liquid velocity, gas velocity, and temperature have enhanced the CO2 absorption flux. Also, adding BZA to aqueous MDEA and K2CO3 significantly increases the CO2 absorption flux in both solutions. Moreover, the mass transfer resistance of individual phases reveals that the liquid phase mass transfer resistance is the controlling phase in non-wetted mode, while with membrane wetting, contribution of membrane side mass transfer resistance increases and become the controlling phase. In general, BZA could be a prominent potential choice as absorbent and promoter for CO2 absorption in HFMCs.