LAUSR

Abstract The enhancement of the solubility parameter of supercritical carbon dioxide plays pivotal role in the application of extraction operation. The solubility parameter of supercritical CO2 solvent (SC-CO2) and supercritical CO2 with cosolvent (SC-CO2-cosolvent) system have been studied using the molecular dynamics simulations (MD). The calculated results reveal that the solubility parameters of pure SC-CO2 solvent and SC-CO2-cosolvent both reduce with the raising of temperature, enhance with the raising of pressure, and boost linearly with the raising of their density. The adding of the cosolvent (methanol, ethanol, acetone and cyclohexane) into the SC-CO2 system can enhance the solubility parameter of SC-CO2 solvent significantly, and the solubility parameter boosts with the raising of the cosolvent concentration. The cosolvent effect on solubility parameter of SC-CO2 solvent decreases in the order: methanol, ethanol, acetone, cyclohexane. The hydrogen bonding ability of the cosolvent has significant effect on solubility parameter of SC-CO2 solvent via the strengthening of the interactions among the CO2 and cosolvent molecules.