Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

ABSTRACT

In this study, interactions between terpenes and alcohols or hydrocarbons have been considered and investigated. With this aim, the (solid + liquid) equilibrium (SLE) phase diagrams for binary systems of {(- )-menthol, or thymol + 1-decanol, or benzyl alcohol, or 2-cyclohexanethanol, or n-decane} were determined at ambient pressure. A dynamic method was used over a broad range of terpene mole fraction and temperature. The simple eutectic mixtures with a complete miscibility in the liquid phase were detected for all systems. The basic thermal properties of the pure terpenes and some solvents, i.e. melting temperatures as well as the enthalpy of fusion, have been measured with differential scanning calorimetry. Thermodynamic modelling of the phase diagrams in terms of the well-known group contribution method modified UNIFAC (Dortmund) as well as molecular-based PC-SAFT equation of state, was carried out in order to assess overall performance of these approaches when used to describe SLE in such complex cross-associating mixtures like these under study. In particular, different predictive strategies for assessing the binary interaction parameters of PC-SAFT model were proposed and tested.