Method for separating methyl acetate-methanol mixture by ionic liquid intermittent extractive rectification

Abstract

The invention discloses a method for separating a methyl acetate-methanol mixture by ionic liquid intermittent extractive rectification, which is realized in a way that: a rectifier of an extractive rectification tower is adopted, an ionic liquid 1-ethyl-3-methyl imidazolyl acetate is used as an extractant, and the operation is carried out intermittently, so the top of the extractive rectification tower sequentially produces a methyl acetate product of which the mass content is up to 98-99.9%, a methyl acetate-methanol transitional fraction and methanol of which the mass content is 97-99%; and finally, the extractant of which the mass percent is 99% is left in the heating kettle. The invention has the following advantages: the extractant is adopted to enhance the relative volatility of the methyl acetate-methanol system, the purity of the separated methyl acetate product is high, and the ionic liquid used as the extractant is easy to recover and does not pollute the environment; and only one single tower needs to be operated, so that operation is flexible and the equipment investment is low.

Description

technical field [0001] The invention relates to an ionic liquid intermittent extraction and rectification separation method of a methyl acetate-methanol mixture, which belongs to the separation technology of the methyl acetate-methanol mixture. Background technique [0002] Extractive distillation is a special rectification method that continuously adds a high-boiling point extractant to the top of the rectification tower to change the relative volatility of the separated components in the feed liquid, so that the liquid mixture that is difficult to separate by ordinary rectification becomes easy to separate. . The methyl acetate-methanol system forms an azeotrope when the mass content of methyl acetate is 81%, and it is difficult to obtain relatively pure methyl acetate by conventional distillation methods, so special distillation methods are required, such as separation and purification by extractive distillation methyl acetate. As an extractant, ionic liquid has the adv...

AI Technical Summary

Problems solved by technology

The methyl acetate-methanol system forms an azeotrope when the mass content of methyl acetate is 81%, and it is difficult to obtain relatively pure methyl acetate by conventional distillation methods, so special distillation methods are required, such as separation and purification by extractive distillation Methyl acetate

As an extractant, ionic liquid has the advantages of easy recovery and no pollution to the environment. So far, there have been no reports on the extraction, rectification and separation technology of this material system.

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