Vapor-Liquid Equilibria and Process Simulation for Separation of Dimethyl Carbonate and Methanol Azeotropic System
加压–常压精馏分离甲醇–碳酸二甲酯的相平衡和流程模拟

Separation of dimethyl carbonate (DMC) and methanol (MeOH) is very difficult due to the azeotrope of DMC and MeOH, the pressure swing method is an effective method for separation of DMC and MeOH azeotrope. In this paper, a joint process of high-pressure distillation and atmospheric distillation was investigated. Binary interaction parameters of the UNQUAC model between MeOH and DMC were regressed against experimental data of vapor liquid equilibria of MeOH and DMC, the applicable range of the model is: pressure 0.1~1.5 MPa, temperature 337~440 K. Based on the thermodynamic model, the separation flowsheet, inclnding a high-pressure distillation column and an atmospheric distillation column in series, was simulated and analyzed. Sensitivity of operation factors was discussed and the optimum operation parameters were proposed. The optimal parameters of the high-pressure distillation column were as follows: stage number 40, feed stage 29, reflux ratio 7~10, operation pressure 1.0~1.5 MPa.