乙酸乙酯-水-异丙醇萃取精馏研究

The Research on the Extractive Distillation of Ethyl Acetate-Water-Isopropanol Azeotropic Mixture

针对精细化工行业废水中异丙醇及乙酸乙酯的回收利用问题,研究了以乙二醇为萃取剂的萃取精馏分离丁酮-水-异丙醇共沸混合物的方法。采用预分离塔,将工业废水进行初步分离,塔顶得到浓缩后的含异丙醇、乙酸乙酯及水的浓缩废液,塔底得到可排放的废水。塔顶得到的粗液则再进行萃取回收系统,降低整个过程中的能耗、萃取剂流量、同时降低萃取剂回收过程中的能耗。并对该非均相萃取精馏进行了工艺模拟计算进行参数优化得到结果,各最终得到产品乙酸乙酯纯度98.8%,异丙醇99.1%,废水中杂质含量均少于50ppm,满足正常生产分离设计要求。对实际生产具有指导意义。

In order to recycle the isopropanol and ethyl acetate in the waste water of fine chemical industry,the method for separating the butanone-water-isopropanol azeotropic mixture by extractive distillation with the ethylene glycol as the extractant is studied.A pre-separation tower is used to preliminarily separate the industrial wastewater.The concentrated waste liquid containing isopropanol,ethyl acetate and water is obtained at the top of the tower,and the dischargeable waste water is obtained at the bottom of the tower.Then the crude liquid obtained at the top of the tower is subjected to an extraction and recovery system to reduce the energy consumption and flow rate of the extractant in the entire process,and to reduce the energy consumption in the recovery process of the extractant.The process simulation calculation of the heterogeneous extractive distillation is car-ried out to optimize the parameters.The purity of ethyl acetate,isopropanol in the final product is 98.8% and 99.1% respectively,and the impurity content in the wastewater is less than 50ppm,which can meet the requirements of normal production separation design.It has a guiding significance for the practical production.