Regenerating method of waste thionyl chloride

Abstract

The invention discloses a regenerating method of waste thionyl chloride. A polyacrylamide / zeolite crosslinking compound adsorption material is prepared from polyacrylamide and zeolite in the absence of a coupling agent, the polyacrylamide / zeolite crosslinking compound adsorption material and waste thionyl chloride are placed in a mixer at normal temperature to be evenly mixed, adsorption is conducted for 60-120 min, depressurized distilling is conducted at 78 DEG C, and the first-grade thionyl chloride with the concentrationof 99.5% is obtained. The problems that waste thionyl chloride is highin recovery energy consumptiom, the process is complex and the environment is polluted are solved; the waste thionyl chloride recovery method which is low in cost, simple in production process, beneficial for industrialization and free of pollution is provided and can be used for recovering the waste thionyl chloride generated in different acylating chlorination production processes.

Description

Technical field: [0001] The invention relates to a regeneration method of waste thionyl chloride, in particular to a purification technology of thionyl chloride which is selectively adsorbed by a polyacrylamide / zeolite cross-linked composite adsorption material and then distilled, and belongs to the technical field of environmental protection. Background technique: [0002] Thionyl chloride is an important fine chemical raw material, widely used in medicine, pesticide, dye industry and organic synthesis industry. The production of acid chloride products is generally to reflux the acid with excess thionyl chloride, and then evaporate the excess thionyl chloride to obtain acid chloride. In the production process, the excess thionyl chloride will be recovered, but the recycled Because sulfoxide contains impurities, its quality is seriously reduced, and it cannot be used in the production of acid chlorides. It can only be disposed of as waste liquid, causing a lot of pollution, ...

AI Technical Summary

Problems solved by technology

[0003] The impurity contained in the newly produced thionyl chloride is mainly sulfur monochloride, and the impurity content is very low. The purpose of product purification is achieved by rectification. The rectification process has high energy consumption and high design cost. Due to the Strong corrosiveness, high investment in rectification equipment

Thionyl chloride recovered after acid chlorination has complex components, including impurities in reactants, unreacted organic acids, by-products, catalysts, catalyst decomposition products, etc. If rectification is used, so many impurities are very difficult to separate

[0004] At present, the waste thionyl chloride is generally treated with sodium hydroxide solution to obtain sodium sulfite and sodium chloride. The absorption rate is only 40%, and the rest that cannot be absorbed is discharged in the form of waste gas. This method is no matter in terms of resources or energy. are very wasteful and cause great environmental pollution.