萃取精馏分离碳酸二甲酯-乙醇二元共沸物

测定了101.3 kPa下乙醇-碳酸二甲酯（DMC）和DMC-糠醛二元体系的汽液平衡数据，以及乙醇-DMC-糠醛体系在溶剂比为1∶1时的三元汽液平衡数据。结果表明，糠醛的加入可以改变乙醇和DMC的相对挥发度，并且当糠醛的摩尔分数大于0.25时，乙醇-DMC二元物系的共沸点消失。因此，可以采用萃取精馏的方法以糠醛为溶剂分离乙醇和DMC的混合物。采用Aspen Plus软件对连续萃取精馏分离乙醇-DMC共沸物的过程进行了模拟。结果表明，单塔带侧线采出的操作方式比双塔操作方式更有优势。

Separation of binary azeotrope ethanol-dimethyl carbonate by extractive distillation

Vapor-liquid equilibrium data of the systems were measured at 101.3 kPa with ethanol-DMC，DMC-furfural and ethanol-DMC-furfural in a solvent ratio of 1∶1. It was shown that furfural can enlarge the relative volatility of ethanol and DMC，and the azeotropic point disappeared when mole fraction of furfural reached 0.25，indicating the feasibility of separating the ethanol-DMC mixture using extractive distillation with furfural as the solvent. Aspen Plus software was used to simulate the continuous extractive distillation processes of ethanol-DMC separation，and the single-column continuous extractive distillation process was preferred than the double-column process.