Vapor–Liquid Equilibria of CO2 + C1–C5 Alcohols from the Experiment and the COSMO-SAC Model

Abstract

The phase behavior of CO2 + alcohols is crucial for the design and optimization of extraction processes that use these alcohols as cosolvents to increase the solubility of polar solutes in supercritical CO2. In this study, the vapor–liquid equilibria (VLE) of CO2 + 2,2-dimethyl-1-propanol are measured at 333.2 K and 353.2 K with a high pressure view cell technique based on the synthetic method. This completes the literature database for binary VLE of CO2 with low mass alcohols up to pentanols. We further systematically investigate the prediction of all binary CO2 + C1–C5 alcohols mixtures with the COSMO-SAC model. Qualitative predictions are obtained when the COSMO-SAC model is combined with the Peng–Robinson–Stryjek–Vera equation of state through the modified Huron–Vidal first-order or the Wong–Sandler mixing rule.