Determination and Correlation for the Solubility of Glutaric Acid in Cyclohexane + Cyclohexanol + Cyclohexanone Solvent Mixtures

The solubilities of glutaric acid in binary cyclohexane + cyclohexanol solvent mixtures at 298.05–343.65 K, in binary cyclohexane + cyclohexanone solvent mixtures at 299.10–340.65 K, in binary cyclohexanone + cyclohexanol solvent mixtures at 299.75–343.65 K, and in ternary cyclohexanol + cyclohexanone + cyclohexane solvent mixtures at 298.15–330.95 K were studied by the dynamic method. The results show that the solubility of glutaric acid increases as temperature increases at constant solvent composition in three determined binary solvent systems. For binary cyclohexane + cyclohexanol and cyclohexane + cyclohexanone solvent mixtures, solubilities of glutaric acid decrease monotonically with the increasing mass fraction of cyclohexane in solvent mixtures at constant temperature. However, for binary cyclohexanone + cyclohexanol solvent mixtures, cyclohexanone with a mass fraction at 0.6 in solvent mixtures has the best dissolving capacity for glutaric acid at constant temperature. The experimental solubility data of three determined binary solvent systems were correlated by the Apelblat equation and nonrandom two-liquid (NRTL) activity coefficient model, and the correlated solubilities data were in good accord with the experimental data. The obtained binary interaction parameters for the NRTL model were used to calculate the solubilities of glutaric acid in the ternary cyclohexanol + cyclohexanone + cyclohexane solvent mixtures, which were compared with the experimental solubilities data.