Mathematical modeling of CO 2 absorption into reactive DEAB solution in packed columns using surface-renewal penetration theory

Abstract

Abstract In this work, a comprehensive model has been developed for CO2 absorption into 4-diethylamino-2-butanol (DEAB) as a reactive amino alcohol solution. The mathematical model is developed based on penetration theory by simultaneous considering of mass transfer phenomenon and chemical reactions. The penetration theory provides appropriate absorption rate and enhancement factor for the chemical absorption. A numerical analysis was performed to solve the applied partial differential equations for the liquid and gas phases simultaneously. The model results were validated using the available experimental data in literature. In this study, the absorption of carbon dioxide by monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), methyldiethanolamine (MDEA) and DEAB solutions was compared theoretically in a packed column absorber. The impact of parameters such as DEAB concentration, temperature, liquid flow rate, CO2 loading and CO2 partial pressure on the performance of a split-flow absorber have been examined. The modeling results indicated that the overall mass transfer coefficient (KGav) for CO2 absorption into DEAB solution was lower than MEA and DEA solutions, however much higher than MDEA and TEA solutions in all range of CO2 loading and partial pressure. Increasing the operating temperature, DEAB concentration and liquid flow rate enhanced the overall mass transfer coefficient.