A Study on Concentration of Ethanol Solution by Supercritical $CO_2$

High pressure vapor-liquid equilibria for and systems were measured using a circulation type of apparatus in which both vapor and liquid phase were continuously recirculated. The conditions to obtain the high ethanol concentration were also investigated. It was possible to concentrate ethanol above the atmospheric ethanol-water azeotropic composition（89.4 mol%） when the system pressure was below the critical pressureof system at which vapor-liquid two phases were coexisted at the ethanol high concentration regime. In the relationships between separation factor(ethanol to water) and ethanol solubility in the supercritical fluid phase, it was found that the calculated values by Patel-Teja equation of state had some errors quantitively with the experimental data, but qualitively represented the similar tendencies.