Organic solvents induced enhancement of phase-splitting behaviors and CO2 absorption performance in biphasic absorbent
Yang Yang, Shaona Wang, Ke Yang, Wenqing Xu, Xueqian Wang, Zanbu Geng, Guoping Liao, Ping Ning, Tingyu Zhu
Abstract
Reducing the rich phase ratio is a key issue for developing the biphasic absorbents. In this study, it is found that the hydrophobic solvents (sulfolane and N, N-dimethylformamide) are beneficial for reducing rich phase volume, while hydrophilic solvents (n-propanol, Polyethylene glycol) inhibit the phase splitting. Sulfolane is the optimal solvent, wherein, the rich phase ratio is greatly reduced from 79 % to 37 %. The CO 2 absorption capacity in the rich phase increases from 2.50 M to 4.25 M. The kinetic studies show that the total mass transfer coefficient is increased by 1.96 times with sulfolane addition. The regeneration energy consumption of the developed absorbent is only 1.85 GJ/t-CO 2 , which is 53.6 % less than MEA. The results can provide a theoretical reference for developing high-performing biphasic absorbents.