Refining method for esterification synthesis of ethylene glycol methyl ether acetate

Abstract

The invention discloses a refining method for esterification synthesis of ethylene glycol methyl ether acetate. The preparation method comprises the following steps: S1, esterification reaction: taking ethylene glycol monomethyl ether and acetic acid as raw materials, preheating, then carrying out metal ion removal pretreatment, and carrying out esterification reaction, S2, dehydration treatment with a liquid phase dehydration membrane: carrying out dehydration treatment on the liquid phase material through the liquid phase dehydration membrane, and heating the treated liquid phase material toenter a reactive distillation tower for rectification, S3, dehydration treatment with a pervaporation membrane: dehydrating the gas-phase material obtained in the step S2 through the pervaporation membrane, enabling the obtained ethylene glycol monomethyl ether to flow back to a reactive distillation tower for reaction, and adding excessive ethylene glycol monomethyl ether to obtain a liquid-phase material at the bottom of the reactive distillation tower, namely a mixture of ethylene glycol monomethyl ether acetate, and S4, heavy component removal treatment: feeding the ethylene glycol methylether acetate mixture into a heavy component removal tower for heavy component removal treatment, so that an industrial-grade finished product is obtained at the tower top. The method has the characteristics of high material conversion rate, small equipment corrosion and low operation cost.

Description

technical field [0001] The invention relates to the technical field of ethylene glycol methyl ether acetate, in particular to an industrial production process of n-butyl acrylate in low-salt waste water. Background technique [0002] Ethylene glycol methyl ether acetate is used as a solvent for metal and furniture spray paint, as a solvent for brush paint, and can also be used as a solvent for protective paint, dyes, resins, leather, inks, and can also be used on hard surfaces such as metal and glass In the formula of cleaning agent, it can also be used as a chemical reagent and has a wide range of uses. [0003] The current industrial route is that the reactant is catalyzed by resin, and toluene or cyclohexane is added as a water-carrying agent. However, due to the miscibility of ethylene glycol methyl ether and water, the amount of sewage treatment is large and the cost is high. [0004] In view of this, it is proposed in China that the gas phase at the top of the tower ...

AI Technical Summary

Problems solved by technology

However, because the reactants contain water, acetic acid, and ethylene glycol methyl ether, and there is a gas-phase association interaction between water and acetic acid, the acidity of the top composition exceeds 0.04%, and there are defects when pervaporation is used alone

Generally, the reaction of acetic acid can be completed by making ethylene glycol methyl ether excessive, but limited by the equilibrium reaction constant, to complete the reaction of acetic acid, the alkyd ratio is too large and the energy consumption is relatively high

[0005] Moreover, liquid-phase dehydration membranes have been proposed at home and abroad, and the temperature of acetic acid resistance can reach 150°C, but they are not resistant to strong acids, such as sulfuric acid and methanesulfonic acid.

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