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. (C) 2012 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.