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Source:Transform the World with Simplicity
The manufacturing method
of vinyl acetate
Vinyl acetate (VA) is an important organic chemical raw material, which is widely used in the production of polyvinyl alcohol, adhesives, coatings, fibers and other chemical products. The following is a method for producing vinyl acetate:
1. the acetylene method
the
acetylene method is a method in which acetylene and acetic acid are reacted as raw materials at 170-250 ° C. in the presence of a zinc acetate catalyst to produce vinyl acetate. The reaction solution was separated by distillation to obtain vinyl acetate product. The method has the advantages of easy availability of raw materials and low production cost, but the reaction process requires high temperature and high pressure conditions, and the equipment investment is large.
2. ethylene method
ethylene method is based on ethylene, acetic acid and oxygen as raw materials, through the oxidation reaction to produce vinyl acetate. The reaction is carried out in a fixed bed reactor using a palladium catalyst, the reaction temperature is controlled at 140-180 ° C., and the pressure is 0.2-0.4MPa. The reaction product is subjected to processes such as condensation, separation and rectification to obtain a vinyl acetate product. Ethylene method has the advantages of easy access to raw materials, mild reaction conditions and simple operation, which is the main production method at home and abroad.
3. ethanol method
ethanol method is based on ethanol and acetic acid as raw materials, in the presence of sulfuric acid catalyst, esterification reaction to generate ethyl acetate, and then ethyl acetate in the presence of zinc powder, at 200-300 ℃ thermal decomposition to generate vinyl acetate. The raw materials of this method are easy to obtain, but the reaction process requires high temperature conditions and high energy consumption.
4. acetaldehyde method
acetaldehyde method is acetaldehyde and acetic acid as raw materials, in the presence of zinc acetate catalyst, the addition reaction to generate vinyl acetate. The raw materials of this method are more expensive and the production cost is higher.
In short, ethylene method is the main production method at home and abroad, with the advantages of easy access to raw materials, mild reaction conditions, simple operation and so on. In the production process, it is necessary to strictly control the reaction conditions to ensure product quality and production safety. At the same time, strengthen equipment maintenance and overhaul, improve equipment operation rate and life, reduce production costs, and improve the economic and social benefits of enterprises.