Mass transfer characteristics of CO₂ absorption into a phase-change solvent in a wetted-wall column

CO₂ from coal-fired flue gas is one of the main components of greenhouse gases. Using phase change absorbents as a solvent can effectively decrease the consumption of regeneration energy for CO₂ capture process. This study employed a mixed solution of diethylenetriamine (DETA) and diethylaminoethanol (DEEA) as the new phase change absorbent for CO₂ absorption. The impact of the phase change behavior on the mass transfer characteristics of CO₂ absorption was investigated in a wetted-wall column. Effects of the temperatures, CO₂ loadings, and gas flow rate on the mass transfer coefficient were also conducted. The results indicated that temperature and CO₂ loading had relatively remarkable effects on the total mass transfer coefficient; whereas the gas flow rate had a smaller effect. Kinetic analysis revealed that the mass transfer resistance of CO₂ absorption into the DETA/DEEA phase change absorbent mainly concentrated at the liquid film side. The findings provide a theoretical reference for the development of new CO₂ phase change absorption technology.