Liquid-liquid equilibrium data for the system limonene plus carvone plus ethanol + water at 298.2 K

This paper presents experimental liquid-liquid equilibrium data at 298.2 K for systems composed of limonene, carvone and hydrous ethanol with five different levels of water in the solvent. The experimental data were correlated using the NRTL and UNIQUAC models, and both thermodynamic equations provided good descriptive quality. In the parameter correlation procedure, mean deviations between the calculated and experimental data of less than 0.0037 were obtained for systems with major contents of water in the solvent. With respect to systems that contained lower concentrations of water in the solvent, we predicted the phase compositions by considering the previously obtained set of parameters. The experimental results showed that as the water content in the solvent phase was increased, the values of the limonene and carvone distribution coefficients decreased. However, the oxygenated compound always exhibited a greater distribution coefficient value. The addition of water to the system also influenced the phase splitting region, and the increased water content in the solvent is responsible for making deterpenation of the essential oil using ethanol a feasible process. (C) 2013 Elsevier B.V. All rights reserved.