A kind of regeneration method of waste thionyl chloride

Abstract

The invention discloses a regeneration method using waste thionyl chloride, which uses polyacrylamide and zeolite to prepare polyacrylamide / zeolite cross-linked composite adsorption materials in the presence of a coupling agent, and cross-links polyacrylamide / zeolite at normal temperature. Combined composite adsorption material and waste thionyl chloride were placed in a stirrer, mixed evenly, adsorbed for 60-120 minutes, and subjected to vacuum distillation at 78°C to obtain more than 99.5% of the first-grade thionyl chloride. The present invention solves the problems of high energy consumption, complex process, and environmental pollution in the recovery of waste thionyl chloride, and provides a waste thionyl chloride recovery method with low cost, simple production process, easy industrialization and no pollution, which can be used in Recovery of waste thionyl chloride from different acyl chloride 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.