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Time:12months ago
Source:Transform the World with Simplicity
Isophthalic acid (IPA) is an important organic chemical raw material, which is widely used in plastics, fibers, pharmaceuticals, pesticides and other fields. The following are several common isophthalic acid manufacturing methods:
1. Phthalic anhydride method
phthalic anhydride method is one of the main methods for the production of isophthalic acid, its raw materials for phthalic anhydride and urea. First, phthalic anhydride and urea are mixed in a molar ratio of 1:1.1-1.2, added to a reactor, and reacted at 180-220°C to generate m-phthalic urea. The isophthalic acid is then obtained by pyrolysis of isophthalic acid at 280-320°C. The advantages of this method are that raw materials are easily available and easy to operate, but a large amount of waste gas and waste water will be generated during the production process, and the environmental protection cost is high.
2. Nitrobenzene
Nitrobenzene method is a more traditional method for the production of isophthalic acid, and its raw materials are nitrobenzene and acetic acid. First, nitrobenzene and acetic acid are mixed in a molar ratio of 1:2-3, added to a reactor, and reacted at 180-220°C to generate m-nitrobenzoic acid. The m-nitrobenzoic acid is then reduced to isophthalic acid. The disadvantage of this method is that a large amount of acetic acid is used in the production process, the cost is high, and a large amount of waste water is produced.
3. m-xylene method
m-xylene method is a relatively new method for the production of isophthalic acid, and its raw material is m-xylene. Meta-xylene is first oxidized to isophthalic anhydride, which is then hydrolyzed to isophthalic acid. The advantages of this method are that the raw materials are easily available, and the waste water and waste gas generated in the production process are less, and the environmental protection cost is lower. However, the reaction conditions of this method are relatively severe, high temperature and high pressure conditions are required, and the equipment investment is large.
No matter which method is used, it is necessary to strictly control the reaction conditions and the proportion of raw materials to ensure the purity and yield of the product. At the same time, it is necessary to pay attention to environmental protection and safety during the production process, and comply with relevant laws, regulations and standards.
In short, isophthalic acid is an important organic chemical raw material, and there are many manufacturing methods, and the advantages and disadvantages of different methods and the scope of application are different. When choosing a production method, you need to consider comprehensively according to the actual situation and choose a method that suits you.