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

CO2capture with a low energy consumption is of important application significance for reducing CO2emission. The phase-change absorbent developed in recent years shows its potential for low-energy CO2capture. The unclear phase-splitting rule hinders the efficient development of CO2phase-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 & Mc Aulay equation and some Density function theory descriptors. Six models based on Debye & Mc Aulay equation were developed with different ion radius, descriptors or poly-amine-CO2products. 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.