乙二醇萃取精馏制备无水乙醇的实验研究

Experimental Study on Anhydrous Ethanol Prepared by Extractive Distillation of Ethylene Glycol

无水乙醇应用广泛,工业上生产方法有多种,其中萃取精馏制取无水乙醇因具有低能耗、无污染、设备简单、操作方便等优点而被受关注。以乙二醇为萃取剂,利用萃取精馏实验装置探讨优化制备无水乙醇过程条件。实验先考察原料乙醇浓度、回流比、溶剂比等因素对萃取精馏得到的产品纯度的影响规律,再通过正交实验优化萃取精馏条件,得到最佳的条件为:原料乙醇浓度为90%(质量分数)、溶剂比为2.6、回流比为3,对应最佳条件塔顶可得到质量分数达99.62%的无水乙醇。

Anhydrous ethanol is widely used and has many production methods,among which extractive distillation has been paid more and more attention because of its advantages of low energy consumption,no pollution,simple equipment and convenient operation.In this paper,ethylene glycol is used as the extractant,and the process conditions for the preparation of anhydrous ethanol are optimized by using the extractive distillation device.The effects of ethanol concentration,reflux ratio,solvent ratio and other factors on the purity of the product obtained by extractive distillation were explored experimentally,and then the conditions of extractive distillation were optimized by orthogonal experiment,and the best conditions were as follows:the ethanol concentration of the raw material was 90%,the solvent ratio was 2.6,and the reflux ratio was 3.Corresponding to this condition,absolute ethanol with a mass concentration of 99.62%was obtained at the top of the tower.