Apparatus for preparing butyric anhydride through reactive distillation of acetic anhydride and butyric acid, and process thereof

Abstract

The invention discloses an apparatus for preparing butyric anhydride through reactive distillation of acetic anhydride and butyric acid, and a process thereof. The apparatus comprises a reactor, a reactive distillation tower, a butyric anhydride refining tower, a condenser, a condenser, a reboiler, a refluxing tank, a kettle tank, a pump and pipelines. The process using the combination of the reactive distillation tower, the rector and the butyric anhydride refining tower comprises the following steps: adding acetic anhydride and butyric acid to the reactor, reacting, and carrying out reaction and rectification on acetic anhydride and butyric acid flowing into the reactive distillation tower on each layer of trays of a reaction section; carrying out stripping section rectification on a material flowing down in the reaction section; carrying out rectifying section rectification on a material rising in the reactions section, and extracting from the tower top to obtain 80-100% acetic acid; pressurizing a material from the bottom of the reactive distillation tower to enter the butyric anhydride refining tower for rectification; and obtaining some of acetic acid, acetic anhydride, butyric acid, acetic butyric anhydride and butyric anhydride at the top of the butyric anhydride refining tower and butyric anhydride with the purity of 80-100% at the bottom of the refining tower. The apparatus and the process solve the problems of unstable quality, low yield and low production efficiency of products intermittently produced by using butyric anhydride.

Description

technical field [0001] The invention belongs to a device and a process for preparing butyric anhydride, in particular to a device and a process for preparing butyric anhydride by reactive distillation of acetic anhydride and butyric acid. technical background [0002] The traditional production methods of butyric anhydride are as follows: co-heating butyryl chloride and sodium butyrate, the by-product of this method, sodium chloride, is easy to crystallize and difficult to remove, the output is small, and the conversion rate is low; butyric acid is dehydrated with sulfur chloride as a catalyst to obtain butyric anhydride , the by-product butyryl chloride pollutes the environment, and there are many side reactions; there are more side reactions between butyric acid and ketene, and the purity of butyric anhydride is low; under the catalysis of cobalt dioxide, butyryl chloride and butyric acid can generate in dichloromethane solvent Butyric anhydride, the yield is low, and the ...

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Problems solved by technology

[0002] The traditional production methods of butyric anhydride are as follows: co-heating butyryl chloride and sodium butyrate, the by-product of this method, sodium chloride, is easy to crystallize and difficult to remove, the output is small, and the conversion rate is low; butyric acid is dehydrated with sulfur chloride as a catalyst to obtain butyric anhydride , the by-product butyryl chloride pollutes the environment, and there are many side reactions; there are more side reactions between butyric acid and ketene, and the purity of butyric anhydride is low; under the catalysis of cobalt dioxide, butyryl chloride and butyric acid can generate in dichloromethane solvent Butyric anhydride, the yield is low, and the energy consumption of separation is high; the exchange method of acetic anhydride and butyric acid is currently produced by batch method in China, and the acetic acid generated by the reaction is continuously distilled to obtain butyric anhydride with higher purity. Due to batch production, Unstable product quality, low yield and low production efficiency

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