Study On Ternary Liquid-Liquid Equilibria Containing 1,8-Cineole

Cineole (1,8-cineole,C10H18O), also known as eucalyptol, the main component of eucalyptus oils, is an environment friendly monoterpenoid (oxygenated), and has wide applications in cosmetic, pharmaceutical, food industries and industrial uses.Phase equilibria are the basis of mass transfer separation processes (unit operations) on distillation, absorption, extraction and so on. This work focuses on cineole and studies the liquid-liquid phase equilibrium property data on the mixtures containing cineole in the processes on separation, recycle, purification and extraction and so on. This work presents the liquid-liquid phase equilibria of 8 (water+light alcohol or dihydric alcohol or naphthenic alcohol) systems at T=(283.15,298.15,313.15) K with a tie-line method; investigates the effect of temperature on the liquid-liquid equilibria, and compares and discusses the distribution ratios of different alcohol in the systems.The experiment results show that the phase diagram of the (water+methanol or ethanol or 1-propanol+cineole) system is type 1, and the distribution ratios of 1-butanol shows higher values; where that of the (water+1-butanol or dihydric alcohol or naphthenic alcohol +cineole) system is type 2, and the distribution ratios of cyclohexanol show the highest values of them. The temperature influence on the (water+alcohol+1,8-cineole) liquid-liquid phase equilibrium systems is very small except the system containing 1,2-propandiol.The experimental ternary liquid-liquid phase equilibrium data were correlated using the NRTL, UNIQUAC and modified UNIQUAC models; the binary interaction parameters of the immiscible subsystems were determined from the mutual solubility data and thermodynamic conditions, while the binary interaction parameters of the miscible subsystems were obtained from the correlation of the experimental ternary liquid-liquid equilibrium data. The results show that the root mean square deviations between the calculated and experimental data are 0.61%,0.57% and 0.82% for the NRTL, UNIQUAC and modified UNIQUAC models, respectively; the both NRTL and UNIQUAC models could reproduce more accurately the experimental results.