Setup and Validation of a PρT Measuring Device. Volumetric Behavior of the Mixture 1,8-Cineole + Ethanol

Abstract

A measuring device, based on the vibrating tube principle, for measuring PρT data is described. The device was checked against the recommended literature values of the 1-hexanol + n-hexane binary system within the temperature and pressure ranges (278.15 to 313.15) K and (0.1 to 20) MPa. The relative deviations between experimental and bibliographic densities are lower than 0.2 %. After the validation, the original mixture 1,8-cineole + ethanol was studied in the ranges (283.15 to 313.15) K and (0.1 to 20) MPa. The isothermal compressibility, the isobaric thermal expansion, and the excess molar volume were derived from the experimental density data, revealing that a volume contraction occurs for this binary system. Four different equations of state, Peng–Robinson, Sako−Wu−Prausnitz, Statistical Associating Fluid Theory (SAFT), and Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT), were applied to predict the volumetric behavior of the ethanolic mixture. The best predictions were achieved with the PC-SAFT equation of state.