DMF与CHCl_3混合液精馏分离工艺的研究

Study on Distillation Separation of DMF and CHCl_3 Mixture

采用模拟的二甲基甲酰胺(DMF)与三氯甲烷(CHCl3)混合液(DMF质量分数为47%),通过精馏塔进行分离。当进料量为2L·h-1时,得出最佳的操作条件如下:进料状态为泡点进料,加料位置为第七块塔板进料,回流比为4。最终结果为:理论塔板数为4.5块,塔板效率为37.5%,塔顶产品DMF质量分数低于0.01%,塔底产品DMF质量分数达到96.03%。该新方法与传统的直接精馏法相比既能减少精馏能耗,又能回收利用DMF,还可使萃取剂CHCl3重复使用,对环境友好不造成污染。

The simulative mixed solution of N, N-dimethylformamide （ DMF ） and trichloromethane （ CHCl3 ）, the mass fraction of DMF in which was 47 %, was separated by distillation. When the rate of feed flow was 2L·h^-1, the optimum operating parameters were as follows： the feed condition was feeding on bubble point, the feed entrance point was the seventh block tray feed from the top and the reflux ratio was 4. The result indicated ： （1） the number of theoretical plates was 4.5, （2） the tray efficiency was 37.5 %, （3） the DMF mass fraction in the product from the top of the packed column was lower than 0.01%, （4） the DMF mass fraction in the product from the bottom was up to 96.03 %. The energy consumption could be reduced, the DMF and the chloroform could be reused by the technology, which was friendly with environment.