A method for rectifying and separating carboxylic acid based on ethylene oxide hydration reaction

Abstract

The invention discloses a method for separating carboxylic acid by means of distillation based on a hydration reaction of ethylene oxide. The method is characterized in that the ethylene oxide and a carboxylic acid crude product aqueous solution are taken as raw materials; the water in the carboxylic acid crude product aqueous solution is consumed by utilizing the fact that the ethylene oxide andthe water can be subjected to the hydration reaction so as to generate ethylene glycol, so that the energy consumption is reduced in a distillation separation process; a product at the bottom of a reactive distillation tower is then sent to a refining tower for purifying by means of rectification, so that a pure carboxylic acid product can be obtained on the top of the tower. Compared with the traditional process of directly purifying the carboxylic acid by means of rectification, the method provided by the invention combines reactive distillation with general distillation, and the hydration reaction and the product separation are realized by means of a double-tower process, so that energy consumption and equipment investment can be effectively reduced; furthermore, the method has the characteristics of not needing an additional catalyst, being rapid in reaction rate and simple in product separation, and the like.

Description

technical field [0001] The invention belongs to the technical field of carboxylic acid purification, and in particular relates to a method for rectifying and separating carboxylic acid based on ethylene oxide hydration reaction. Background technique [0002] Carboxylic acid is an important chemical raw material with a wide range of applications. It plays an important role in the fields of chemical industry, medicine, textile, organic synthesis, rare earth element refining, dye intermediates and leather industry. Derivatives of carboxylic acids, such as acyl halides, anhydrides, esters and amides, also have important applications in the chemical industry. [0003] The crude products of carboxylic acids (such as acetic acid) produced by fermentation are mostly low-concentration aqueous solutions, so dehydration and purification are required to obtain refined carboxylic acid products. At the same time, some low-concentration carboxylic acids are often contained in the industri...

AI Technical Summary

Problems solved by technology

The amount of solvent used in the extraction method is large, and the solvent used is serious to the pollution of the environment; due to the high water content of the crude carboxylic acid product in the direct distillation method, the specific heat of water is relatively large, and most carboxylic acids can associate with water, adding Increased the difficulty of rectification and separation, resulting in the consumption of huge energy in the rectification process

Images