Method for preparing isoamylene by taking tertiary amyl methyl ether as raw material

Abstract

The invention relates to a method for preparing isoamylene by taking tertiary amyl methyl ether as raw material, comprising the following steps: making methyl tert-amyl ether to be subjected to decomposition reaction at 130-300 DEG C with the gas phase through a catalyst bed layer; removing methanol in the products of decomposition reaction to obtain rough isoamylene; and adding water to the rough isoamylene to enable the rough isoamylene to be subjected to the isomerization reaction through a fixed bed catalyst bed layer which is formed by sulfonic cation exchange resin and enable 2-methyl-1-butene in the rough isoamylene to be converted into 2-methyl-2- butane, wherein the addition amount of the water is 0.03-0.10 percent by weight of the rough isoamylene, and the mass exchange capacity of the sulfonic cation exchange resin is 3-5.5 mmol / g, the mass space velocity is 1-35hr-1, the reaction temperature is 18-45 DEG C and the reaction pressure is 0.3-1.0 MPa. The invention effectively controls the occurence of the dimerization reaction in the isomerization reaction process.

Description

technical field [0001] The present invention relates to a method for preparing isopentene by using methyl tert-amyl ether as a raw material, in particular to isomerization reaction of crude isopentene obtained by etherolysis through a fixed-bed catalyst composed of sulfonic acid-based cation exchange resin , to improve the method for preparing isopentene of which 2-methyl-2-butene content. Background technique [0002] Isoamylene is an important chemical raw material used in the production of resins and pesticide intermediates. Isoamyl is usually a mixture of 2-methyl-2-butene and 2-methyl-1-butene. Since only 2-methyl-2-butene is the active ingredient for most reactions, isoamyl The higher the 2-methyl-2-butene content, the higher the application value. [0003] Isoamylene mainly exists in the C5 fraction of catalytic cracked gasoline or the C5 fraction of the by-product of naphtha cracking to ethylene. Since these C5 materials contain many compounds with very close boili...

AI Technical Summary

Problems solved by technology

[0004] However, while the isomerization reaction is carried out, 2-methyl-2-butene and 2-methyl-1-butene are all prone to dimerization reactions individually or with each other. Dimer content will reach about 4wt%

Although the dimer can be removed through the refining process, this will lead to a decrease in product yield and an increase in energy consumption

On the other hand, the reaction heat of the dimerization reaction will also cause abnormal fluctuations in the temperature of the catalyst bed, making it difficult to control the isomerization reaction smoothly.

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