Technology for separating ethylene glycol monomethyl ether and water by use of continuous azeotropic distillation method

Abstract

The invention discloses a technology for separating ethylene glycol monomethyl ether and water by use of a continuous azeotropic distillation method. The technology comprises the following steps of: 1) an entrainer is added into a tower kettle of an azeotropic distillation tower, the raw material enters the azeotropic distillation tower from the 28th tower plate, the operation reflux ratio is 1-3, and the reflux flows back from the tower top of the azeotropic distillation tower; and after phase splitting, the ester-rich phase enters the azeotropic distillation tower, the water-rich phase enters an entrainer recycling tower, and the product of the tower kettle of the azeotropic distillation tower is ethylene glycol monomethyl ether; and 2) after the water-rich phase enters the entrainer recycling tower, common distillation is carried out, wherein the operation reflux ratio is 1-2.5, and the reflux flows back from the tower top of the entrainer recycling tower; and after phase splitting of the produced liquid, the water-rich phase enters the entrainer recycling tower, and water is contained in the tower kettle of the entrainer recycling tower. By taking isopropyl acetate as an entrainer, the technology disclosed by the invention has the characteristics of low toxicity, low pollution, low cost, high yield, high product purity and the like, has wide application prospect, and is particularly suitable for the fields of pharmacy and the like.

Description

technical field [0001] The invention relates to a process for recovering ethylene glycol monomethyl ether in a mixed solution of ethylene glycol monomethyl ether and water in the fields of pharmacy and the like. Specifically, the entrainer isopropyl acetate is added, and all the water in the mixed solution of ethylene glycol monomethyl ether and water is taken out by continuous azeotropic distillation, thereby recovering the ethylene glycol monomethyl ether in the mixed solution. Simultaneously realize the technological method of recycling and reusing the entrainer. Background technique [0002] Ethylene glycol monomethyl ether, also known as ethylene glycol methyl ether, is a colorless transparent liquid with a boiling point of 124.6°C (101.3KPa), and is miscible with water, alcohol, ether, acetone and DMF. It is widely used as a solvent for various oils, cellulose acetate, nitrocellulose, alcohol-soluble dyes and synthetic resins. Quick-drying solvent for enamel and varn...

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Problems solved by technology

[0007] The purpose of this invention is to provide a kind of processing method of azeotropic rectification separation ethylene glycol monomethyl ether and water, it uses isopropyl acetate as entrainer, can reclaim from ethylene glycol monomethyl ether-water waste liquid The high-purity ethyle

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