A method for extracting and rectifying separation of toluene and n-butanol mixture

Abstract

The invention relates to a method for separating methylbenzene and n-butyl alcohol mixture through extractive distillation. The method comprises the steps that dimethyl sulfoxide is used as an extracting agent to be introduced from the upper portion of an extractive distillation tower to make sufficient contact with the methylbenzene and n-butyl alcohol mixture introduced from the middle of the extractive distillation tower, after extractive distillation, methylbenzene is extracted from the top of the extractive distillation tower, and the extracting agent and n-butyl alcohol mixture enters an extracting agent recycling tower from the bottom of the extractive distillation tower. Through effective separation, n-butyl alcohol is extracted from the top of the extracting agent recycling tower, and the extracting agent is extracted from the bottom of the extracting agent recycling tower to be recycled. The process has the advantages of being low in energy consumption, simple in process, high in separation purity and the like.

Description

【Technical field】 [0001] The invention belongs to the field of separation and purification in the chemical industry, in particular to a method for extracting and rectifying the separation of a mixture of toluene and n-butanol. 【Background technique】 [0002] Toluene is widely used as a solvent and high-octane gasoline additive, and is also an important raw material for organic chemical industry. A series of intermediates derived from toluene are widely used in the production of fine chemicals such as dyes, medicines, pesticides, gunpowder, additives, and spices, as well as in the synthetic material industry. Benzyl chloride, benzyl dichloride and benzyl trichloride obtained by side-chain chlorination of toluene, including their derivatives benzyl alcohol. The cyclic chlorination products of toluene are intermediates of pesticides, medicines and dyes. Toluene is oxidized to obtain benzoic acid, which is an important food preservative and also used as an intermediate in orga...

AI Technical Summary

Problems solved by technology

[0007] The defects and deficiencies existing in the above-mentioned existing separation technology are: in the operation process of separating the azeotrope in the high and low pressure column of pressure swing rectification, the pressure requirement is relatively strict, so higher requirements are put forward for the performance of the column equipment; In the case of distillative separation of acetonitrile-toluene, due to the selection of the extractant, the reflux is relatively large, and the energy consumption in the rectification process is too high; the operation process is relatively complicated; the purity of the recovered products is less than 99.9%, and the purity is relatively low

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