复合溶剂间歇萃取精馏分离乙酸乙酯-乙醇物系

Separation of Ethyl Acetate-Ethanol by Batch Extractive Distillation with Mixed Solvent

使用单一溶剂N,N-二甲基甲酰胺(DMF),二甲基亚砜(DMSO)和复合溶剂DMF-DMSO对乙酸乙酯-乙醇物系进行了间歇萃取精馏的实验。考察了溶剂种类、溶剂比、回流比等因素对分离效果的影响,比较了使用单一溶剂和复合溶剂时的间歇萃取精馏实验所需的操作时间。实验结果表明,复合溶剂DMF-DMSO的分离效果最好,采用复合溶剂DMF-DMSO时,适宜操作条件:n(DMF):n(DMSO)=2:3,溶剂加入速率25mL/min,溶剂与产品质量比5.0,回流比3.3,此时塔顶产品中乙酸乙酯的质量分数为99.52%;且使用复合溶剂DMF-DMSO时间歇萃取精馏的操作时间比使用单一溶剂所需的操作时间短,单位质量产品能耗较使用单一溶剂DMF时降低了42.6%,较使用单一溶剂DMSO时降低了37.4%。

The separation of ethyl acetate-ethanol azeotropic system was carried out through a batch extractive distillation processes with N, N-dimethylformamide （ DMF）, dimethyl sulfoxide （DMSO） and DMF-DMSO mixture as solvents separately. The effects of the solvent type, solvent ratio （mass fraction of solvent to the product ethyl acetate at the column top） and reflux ratio on the separation were studied. It was found that the mixed solvent DMF-DMSO showed the best separation effect and the concentration of the product ethyl acetate could reach 99.52% under the optimum conditions： mole ratio of DMF to DMSO 2 ： 3, solvent flow rate 25 mL/min, solvent ratio 5.0 and reflux ratio 3.3. Through using the mixed solvent, the operation time could be shortened and the energy consumption of unit product mass could lowered by 42. 6% and 37. 4% compared with using DMF and DMSO respectively.