Preparation method and production device of thioacetic acid

Abstract

The invention discloses a preparation method and a production device of thioacetic acid. The thioacetic acid is obtained through carrying out low temperature reaction by adopting acetic acid and phosphorus pentasulfide under the action of a specific catalyst, carrying out solid-liquid separation, and carrying out distillation separation on a liquid phase. A solid-phase substance obtained through solid-liquid separation for the first time is further extracted and purified, so that a byproduct potassium phosphate is obtained. Low-price and easy-to-get raw materials and the catalyst are adopted and can be reacted to synthesize to obtain the thioacetic acid at lower temperature and pressure intensity and even at normal pressure and temperature, solid-liquid separation is carried out to obtainthe liquid phase, and the liquid phase is subjected to distillation separation so as to obtain the thioacetic acid with high purity and high yield. Through further extracting and purifying the solid-phase substance obtained through solid-liquid separation for the first time, the high-value-added byproduct potassium phosphate with high purity and high yield is obtained from the waste liquid, so that the preparation method is friendly to the environment and has higher economical efficiency.

Description

technical field [0001] The invention relates to the technical field of preparing chemical intermediates, in particular to a preparation method and production device of thioacetic acid. Background technique [0002] Thioacetic acid is a fine chemical intermediate with certain corrosiveness and wide application. The synthesis process of thioacetic acid is mainly divided into two routes, one is to use hydrogen sulfide and acetic anhydride to react to generate thioacetic acid. The second is to use phosphorus pentasulfide to react with acetic acid to generate thioacetic acid. [0003] The process of using hydrogen sulfide as raw material is relatively complicated and dangerous, and generally requires an independent hydrogen sulfide preparation device. Using the synthesis process of phosphorus pentasulfide and acetic acid as raw materials, it is obtained by co-heating distillation of acetic acid and phosphorus pentasulfide, heating to 91 ° C to start distilling thioacetic acid, ...

AI Technical Summary

Problems solved by technology

[0003] The process of using hydrogen sulfide as raw material is relatively complicated and dangerous, and generally requires an independent hydrogen sulfide preparation device

Using the synthesis process of phosphorus pentasulfide and acetic acid as raw materials, it is obtained by co-heating distillation of acetic acid and phosphorus pentasulfide, heating to 91 ° C to start distilling thioacetic acid, the co-heating process needs to monitor the temperature from time to time not to be higher than 100 ° C, and at the same time to prevent bumping, Therefore, the operation is complicated, and the reaction process is difficult to control. In order to increase the content of thioacetic acid, the distillate needs to be re-distilled

In addition, the solid phase remaining from distillation is difficult to handle, endangering the environment, and because the process is difficult to control, it cannot be mass-produced industrially

At the same time, the corresponding production equipment is more complicated, difficult to operate, and more dangerous

The yield and purity of the finally obtained thioacetic acid are also unsatisfactory

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