A Unified Thermodynamics Model for Solid–Liquid Equilibrium, Liquid–Liquid Equilibrium, and Vapor–Liquid Equilibrium of Cyclohexane Oxidation Systems: NRTL Model

The solubility of adipic acid (AA), glutaric acid (GA), and succinic acid (SA) in acetic acid (HAc) + cyclohexanol solvent mixtures was measured by the laser dynamic method. The experimental temperature ranged from 300.75 to 347.05 K, and the mole fraction of HAc in the solvent mixtures ranged from 0.0000 to 1.0000. Together with the available solid–liquid equilibrium (SLE) and liquid–liquid equilibrium (LLE) data of the oxidation for cyclohexane in the published literatures, the interaction parameters of the NRTL (non-random two-liquid) model are determined by correlating a large number of experimental data. By using the new interaction parameters, the NRTL model predicted vapor–liquid equilibrium (VLE), SLE, and LLE data well in extrapolating temperature and solvent composition for the cyclohexane oxidation systems, which was in agreement with the experimentally determined results and was satisfactorily in agreement with previously published literatures. The results showed that the NRTL model would be a suitable one for the unified thermodynamics model which can be used for the correlation and prediction of the SLE, LLE, and VLE data for the cyclohexane oxidation process.