甲醇-碳酸二甲酯二元共沸物的分离

The Separation of Methanol-DMC Azeotrope Mixture

分别用共沸精馏法和萃取精馏法对甲醇-碳酸二甲酯(DMC)二元共沸体系进行了分离,通过正交实验分别得到了最佳分离工艺条件。实验结果表明,共沸精馏法的最佳分离工艺条件:共沸剂正己烷用量为总质量(共沸剂+甲醇)的76%,回流比控制在3:1,馏出速率为6mL/min;萃取精馏法的分离最佳工艺条件:以糠醛为萃取剂,回流比控制在3:1,萃取剂滴加速率为3mL/min,萃取剂配比为4:1。并分别从装置和纯度方面对两种方法进行比较,结果表明萃取精馏法占优。

Methanol-DMC binary azeotropic system were separated by azeotropic rectification and extractive rectification, respectively. The optimal operating conditions were obtained by using orthogonal experiment method. Experimental results showed that, for azeotropic rectification , the optimal conditions were azeotropic agent mass weight using 3.16 times to that of methnol, reflux ratio of 3：1, distillate rate of 6 mL/min, respectively. For extractive rectification, the optimal separation conditions were using furfural as extraction agent, control reflux ratio of 3：1, the dropping rate of 3 mL/min, extraction ratio of 4：1. It was found that the extractive rectification was better than the azeotropic rectification through comparing the purity of DMC and operational technology.