Reactive distillation method for producing methyl methacrylate

Abstract

The invention relates to a reactive distillation method for producing methyl methacrylate. The method comprises steps of synthesizing the methyl methacrylate in a rectifying column; separating a target product from raw materials through azeotropic distillation while reacting, thereby obtaining an organic phase which does not contain methacrylic acid and is rich in methyl methacrylate from a column top and obtaining a solution which contains a great quantity of methacrylic acid from a column bottom; connecting a film evaporator with the column bottom in series; and further concentrating the heavy components of the column bottom so as to reduce the consumption of the methacrylic acid. An azeotropic distillation technology is utilized to separate the methyl methacrylate from acid; a whole rectifying system is integrated and coupled; one reacting and rectifying column is used to realize reacting and rectifying; tasks such as esterification, raw material and product separation and heavy component decomposition which need to be completed by a plurality of columns are completed at the same time; the organic phase which does not contain methacrylic acid and is rich in methyl methacrylate is obtained from the column top; and an original complicated technology is simplified.

Description

technical field [0001] The invention belongs to the technical field of chemical synthesis and relates to a reactive distillation method for producing methyl methacrylate. technical background [0002] Methyl methacrylate (MMA) is a colorless and volatile liquid at room temperature with a strong spicy taste. The melting point is -48.2°C, the boiling point is 100.3°C, the relative density is 1.009 (20 / 4°C), the refractive index is 1.412, and the flash point is 11°C. Slightly soluble in water, easily soluble in ethanol, etc. [0003] Methyl methacrylate is an important organic chemical raw material and the most important industrial product among methacrylates. It is mainly used to manufacture various polymers and copolymers. MMA is also used to manufacture resins, plastics, and coatings. , Adhesives, lubricants, sizing agents for wood and cork, impregnation agents for motor coils, paper polishes, printing and dyeing auxiliaries and insulating potting materials, etc. [000...

AI Technical Summary

Problems solved by technology

[0016] The methods disclosed above all adopt the process of reaction plus rectification, and use a single reactor for esterification reaction, and then obtain the final product through rectification purification. Usually, this reaction method needs to adopt a longer residence time in order to obtain a high conversion rate. time, resulting in the required larger reactor volume, the reason is that in order to vaporize the reaction product, the reactor temperature is higher, and methanol, water, and methyl methacrylate also form an azeotrope, which reduces the concentration of methanol in the reaction zone and makes the ester decrease in reaction rate

In addition, there is no catalyst in the separation tower, methanol can no longer react, and a large amount of unreacted alcohol is recovered in the rear system and returned to the reactor, resulting in increased energy consumption

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