The quasi-activity coefficients of non-electrolytes in aqueous solution with organic ions and its application on the phase splitting behaviors prediction for CO2 absorption

CO2 capture with a low energy consumption is of important application significance for reducing CO2 emission. The phase-change absorbent developed in recent years shows its potential for low-energy CO2 capture. The unclear phase-splitting rule hinders the efficient development of CO2 phase-change absorbents. To predict phase-splitting behaviors of mono/poly-amine-organic solvent-water system with various concentrations, a quasi-activity coefficient was developed based on Debye & McAulay equation and some Density function theory descriptors. Six models based on Debye & McAulay equation were developed with different ion radius, descriptors or poly-amine-CO2 products. The phase-splitting boundary was drawn on the model with the best predictability. This quasi-activity coefficient would provide guidance for the phase-splitting systems development, especially for polyamines. (C) 2022 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.