Modeling CO2 solubility in imidazolium-based ionic liquids with extended PC-SAFT equation of state

This study models the interchange energy in Guggenheim's lattice fluid theory for application in PC-SAFT, namely cQC-PC-SAFT, to predict the CO2 solubility in imidazolium-based ionic liquids. cQC-PC-SAFT-MSA incorporates the charge interactions within the ionic liquid and the charging-discharging effect, adding the Mean Spherical Approximation (MSA) term and the Born term to the basis of cQC-PC-SAFT. Furthermore, three optimization schemes for binary parameters were tested for cQC-PC-SAFT-MSA. By calculating the CO2 solubility in ten imidazolium-based ionic liquids, the results show the predicted CO2 solubility in ionic liquids by both cQC-PC-SAFT and cQC-PC-SAFT-MSA shows significant improvement compared to PC-SAFT with k(iJ) = 0. Moreover, with the optimization of binary parameters, cQC-PC-SAFT-MSA provides an accurate prediction for the CO2 solubility in ionic liquids at pressures below 6000 kPa.