Prediction of solubilities of solid solutes in carbon dioxide-expanded organic solvents using the predictive Soave–Redlich–Kwong (PSRK) equation of state

In this study, the solubilities of solid solutes in carbon dioxide (CO2)-expanded organic solvents are predicted using the predictive Soave–Redlich–Kwong (PSRK) equation of state (EOS). The liquid-phase compositions and volume expansion ratios of CO2-expanded organic solvents are predicted prior to the solubility predictions. With predicted liquid-phase compositions and volumetric properties, the solubilities of cholesterol in CO2-expanded acetone, naphthalene in CO2-expanded toluene, stearic acid in CO2 expanded ethyl acetate and tetradecanoic acid in CO2-expanded ethyl acetate are predicted according to their reference solubilities in pure organic solvents. In addition to satisfactory predictions of liquid-phase composition and volume expansion ratios, the PSRK EOS also provides qualitative prediction ability for solubilities of solid solutes in CO2-expanded organic solvent. This study demonstrated that the PSRK EOS was a simple model with predictive ability for solubility evaluation in preliminary process design and development for supercritical fluid technology using CO2-expanded organic solvents.

► The solubilities of solid solute in CO2-expanded organic solvent are predicted qualitative using the PSRK EOS. ► Four solid solids including naphthalene, cholesterol, tetradecanoic acid and stearic acid are considered in this calculation. ► The PSRK EOS provides a simple model with sufficient accuracy and predictive ability for solubility evaluations.