Method for separating ethanol-water-cumene mixed solution by single-side extraction and azeotropic distillation

Abstract

The invention discloses a method for separation of an ethanol-water-isopropylbenzene mixed solution through unilateral extraction and azeotropic rectification. The method is characterized in that a unilateral extraction and azeotropic rectification tower is composed of an extraction rectification section and an azeotropic rectification section, wherein the extraction rectification section is connected with the azeotropic rectification section through a downcomer; the ethanol-water-isopropylbenzene mixed solution is fed through the middle lower part of the extraction rectification section; a modification extracting agent is fed through the middle upper part of the extraction rectification section and is a dioctyl diphthalate solution which contains 4wt%-10wt% of MgSO4; the ethanol of which the concentration is above 99.9% is obtained at the top of the tower; a mixed solution at the bottom flows to the azeotropic rectification section through the downcomer so as to be treated; mixed liquid and steam of isopropylbenzene and water is discharged from a lateral discharging hole of the azeotropic rectification section; the mixed liquid and steam is condensed and then divided into an isopropylbenzene layer and a water layer; the isopropylbenzene layer contains more than 99% of the isopropylbenzene; the water layer contains less than 0.2% of the isopropylbenzene and ethanol; and a liquid flowing out of the bottom of the azeotropic rectification tower is the modification extracting agent of which the concentration is above 99.7% and is circulated to the extraction distillation section for cycle use.

Description

Technical field [0001] The invention relates to an integrated process for the separation of multiple components, in particular to a method for separating ethanol-water-cumene mixed solution by single-side line extraction azeotropic distillation. Background technique [0002] Cumene is an important basic organic chemical raw material, mainly used to produce phenol and acetone, which are widely used. At present, the global output of cumene is nearly 10 million tons. More than 90% of the cumene is used to produce phenol and acetone. Other uses are as thinners for paints, varnishes and enamel enamels, as well as for certain petroleum solutions. Ingredients and components used as high-octane aviation fuel oil. In addition, cumene can also be used to make polymerization and oxidation catalysts, and from it to produce products such as acetophenone, α-methylstyrene and peroxide. It is estimated that in the next ten years, cumene will increase at an annual growth rate of 3.8%, of which ...

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Problems solved by technology

[0003] During the sulfonation reaction of cumene and sulfuric acid to generate cumene sulfonic acid, ethanol is added to the product to obtain cumene sulfonic acid through crystallization, and the remainder is an aqueous solution of ethanol and cumene. Due to ethanol, There are complex binary and ternary azeotropes between water and cumene, see figure 1 As shown, the azeotropic point between ethanol and water is 78.17°C, the azeotropic point between ethanol and cumene is 80.5°C, the azeotropic point between ethanol, water and cumene is 84.0°C, and the azeotropic point between water and cumene The azeotropic point between them is 96.0°C, so it is difficult to separate and extract ethanol and cumene in the remaining mixed liquid by conventional distillation

At present, the ethanol-water-cumene mixed solution mainly adopts the adsorption method to remove water, and then mixes ethanol and cumene as fuel. This method seriously wastes ethanol and cumene, resulting in high production cost of cumene sulfonic acid. and cause adverse effects on the environment

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