Technique for producing chloroactic acid through high temperature and high pressure method and its equipment

Abstract

The invention relates to a process and equipment for producing chloroacetic acid by a high-temperature and high-pressure method, and belongs to the technical field of chloroacetic acid preparation. It adds acetic acid and acetic anhydride equivalent to 10% to 15% of acetic acid in the reactor, keeps the temperature at 80-200°C, pressurizes at 0.8-4.0MPa, feeds chlorine gas for chlorination, and fractionates the chlorinated liquid in the reactor. Fractional distillation in the tower, cooling the kettle liquid to 70-80°C, enclosing it in a soft container and stirring it to crystallize naturally to obtain the chloroacetic acid product. The outer temperature control jacket of the reaction kettle is divided into upper and lower sections, the upper section is a cooling jacket, and the lower section is a heating jacket. A pressure relief and pressure regulating valve is installed between the hydrochloric acid absorption tower and the condenser. The invention is characterized by simple process, short cycle, low cost, no pollution, high product quality and high yield. The equipment has reasonable structure, easy temperature control, convenient and flexible operation. Suitable for industrial production of chloroacetic acid.

Description

technical field [0001] The invention belongs to the technical field of preparation of chloroacetic acid. Background technique [0002] Most manufacturers in China now use traditional methods to produce chloroacetic acid. The method is to use acetic acid and chlorine gas as raw materials, sulfur as a catalyst, and chlorine gas to be chlorinated at 80-100 ° C and normal pressure. And use the method of measuring specific gravity to determine the degree of chlorination. When the specific gravity of the feed liquid reaches 1.35 at 80°C, it is the end point of chlorination. At this time, the chlorination solution generally contains 89% monochloroacetic acid, 5-7% dichloroacetic acid, 3% acetyl chloride, and 2% acetic acid. Next, put the chlorinated solution into the stirring pot, then add the mother liquor (mainly composed of dichlorine) which accounts for about 1 / 3 of the feed liquid, and slowly cool down and crystallize under stirring for more than 24 hours. When the crystal...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is: if we want to obtain higher yield, we will generate less dichloride and less acetic acid at the same time. These two requirements are contradictory and difficult to grasp in production.

It is said that the equipment investment and operating costs are very large

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