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.