Kinetics study and performance evaluation of a hybrid choline-glycine/polyethylene glycol/water absorbent for CO2 separation
Yifeng Chen, Sida Liu, Kang Sun, Jianchun Jiang, Dong Wang, Zhuhong Yang, Xiaoyan Ji
Abstract
Thermodynamic and kinetic properties of absorbents are beneficial in evaluating their CO2 separation performance. In this study, the kinetic properties of CO2 in a hybrid choline-glycine/polyethylene glycol/water absorbent, including the liquid-side mass-transfer coefficient, enhancement factor, and reaction rate constant, were systematically determined through experimental measurements and data processing. Furthermore, an index referred to as “absorbility” was proposed to combine the kinetic properties determined in this study with the thermodynamic properties obtained in our previous study to evaluate the CO2 separation performance. Additionally, the regeneration performance of the hybrid absorbent was also conducted. The results show that the performance of the hybrid absorbent (30 wt% [Cho][Gly] + 10 wt% PEG200 + 60 wt% H2O) is comparable to that of aqueous monoethanolamine, and is thus promising for CO2 separation, considering its low regeneration temperature and low environmental impact.