Vapor-liquid equilibria of CO₂ + C1-C5 alcohols from the experiment and the COSMO-SAC Model

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.