Liquid-liquid equilibrium of rosemary model essential oil (α-pinene + eucalyptol + camphor) and solvent (ethanol + water) at room conditions

Rosemary essential oil is composed of key components used in pharmaceutical and cosmetics products worldwide. Among several components found in rosemary essential oil, it can be simplified by a mixture of α-pinene, eucalyptol, and camphor. Aiming an enhanced product quality, the separation of eucalyptol and camphor from α-pinene was evaluated employing ethanol + water mixtures as solvents. For that, liquid-liquid equilibrium data of systems composed of α-pinene + eucalyptol + camphor + ethanol + water at T = (298.2 ± 0.1) K were thus assessed. Thermophysical properties of the phases from the equilibrium as density, viscosity, surface tension, and interfacial tension were also evaluated. Increased water amount in the solvent caused decreased distribution coefficients, but higher solvent selectivity and thermophysical properties. Increased oxygenated compounds in the terpene phase also led to enhanced density and viscosity values, but lower solvent selectivity and interfacial tension. Binary interaction parameters of the NRTL adjusted to the experimental data and empirical equations described satisfactorily the phases compositions and thermophysical properties, with relative deviations of 0.73% for NRTL, 0.006% for density, 0.22% for viscosity, 5.78% for surface tension, and 5.88% for interfacial tension. [Display omitted]