| In this study, DMC was sythesized by methanol carbonylation in liquid phase method, with the product composition of 70% methanol and 30% DMC. The methanol-DMC azeotropic system is difficult to separate. This study presented an extractive distillation of the azeotropic system with N-hexane as the agent, and the Vapor-liquid equilibrium was studied for the distillation of system.The vapor-liquid data were obtained on the device of double loop reactor and gas chromatography. The isopropyl alcohol-water system was used to test the reliability of the device, and the measured vapor-liquid equilibrium data were consistent with the literature values, showing that the device is reliable. Measured using the device the vapor-liquid equilibrium data of three different binary systems, dimethyl carbonate (1)-methanol (2), dimethyl carbonate (1)-hexane (2) and methanol (1)-hexane (2) were measured on this device at, different temperature and pressure of 1.01×105 pa. These data were tested through a method of integration, with the results corresponding with the thermodynamic consistency. The activity coefficient equation parameters of three binary systems at different temperatures were regressed on the Wilson, NRTL, UNIQUAC model. The results indicated that the parameters and temperature showed a best correlation and a minimal average deviation in UNIQUAC equation. The deviations of models were analyzed and the ternary gas composition was calculated based on the model parameters. The calculated and experimental results were in a good agreement. In which, the average relative deviation of gas composition projected from the UNIQUAC-model was minimum, indicating that UNIQUAC model was better for corresponding with the vapor-liquid equilibrium data than the Wilson model and the NRTL model. This study provided data, effective thermodynamic parameters and mathematical model references for the separation of methanol (1)-DMC (2)-hexane (3) system.
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