System and method for rectifying and purifying food grade ethyl lactate into electronic grade ethyl lactate

Abstract

The invention discloses a system and method for rectifying and purifying food grade ethyl lactate into electronic grade ethyl lactate. The method comprises the following steps of: performing heat exchange on a food grade ethyl lactate feed solution with a raw material preheater, and making the food grade ethyl lactate feed solution enter the middle part of a lightness-removing column; removing a small quantity of impurity light components and losing a small amount of ethyl lactate; making tower kettle material flow which contains pure ethyl lactate enter the middle part of a weight-removing column; and removing heavy components such as heavy metals and the like and losing a small amount of ethyl lactate to obtain an electronic grade ethyl lactate product on the top of the column, wherein the column top operation pressure of the htness-removing column is 15.0-20.0Kpa, the column bottom operation temperature is 101.0-107.9 DEG C, the reflux ratio is 80.0-120.0, and the theoretical grade is 80-120; the column top operation pressure of the weight-removing column is 6.7-8.0KPa, the column bottom operation temperature is 87.4-90.4 DEG C, the reflux ratio is 3.0-10.0, and the theoretical grade is 90-120 DEG C; the product purity of the electronic grade ethyl lactate is more than or equal to 99.5 percent, the total metal content is less than 100 ppb, the moisture is less than 0.05 percent, and the acidity is less than 0.05 percent; and the product recovering rate in the process is more than 98.0 percent.

Description

technical field [0001] The invention relates to a method for purifying ethyl lactate, in particular to a system and method for rectifying and purifying food-grade ethyl lactate into electronic-grade ethyl lactate, and belongs to the field of separation and purification of ethyl lactate. Background technique [0002] Ethyl lactate is also known as α-hydroxy ethyl propionate, English name: ethyl lactate, molecular formula is C 5 h 10 o 3 , completely miscible with water and partially decomposed, easily soluble in alcohols, ethers, ketones and esters. Ethyl lactate is a colorless and transparent liquid with a wine aroma, widely used as a flavor and flavor synergist in the food industry, and used as a plasticizer in other industries, and is a new type that meets environmental protection requirements. The green solvent, especially the purified electronic grade ethyl lactate is used as a lubricant for pressing pharmaceutical tablets in the pharmaceutical industry. At the same t...

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Problems solved by technology

For example: the ethyl lactate obtained by the rectification process of ethyl lactate reported in patents 93118797.4 and 94107040.9 can only reach food-grade standards; the purification method of ethyl lactate reported in patent 200910028648.9 has a relatively complicated process and can obtain a purity of about 99% at most. Food grade ethyl lactate

And most of the existing ethyl lactate purification methods are batch processes, which are not suitable for large-scale production

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