Method for preparing tert-butylamine from isobutene

Abstract

The invention relates to a method for preparing tert-butylamine from isobutene, which is characterized in that isobutene, liquid ammonia, amines and phenol are contacted with a molecular sieve catalyst for amination reaction to prepare tert-butylamine, the amines have the following structural general formula, and R1, R2 and R3 are respectively and independently selected from H and C1-C5 alkyl groups. The amine and phenol assistants are added into a reaction system for preparing tert-butylamine through amination of isobutene, on one hand, the amine can improve the surface acid environment of a molecular sieve catalyst, an amination reaction active site is formed, and diffusion resistance of isobutene to the surface of the catalyst is reduced, and on the other hand, phenol can increase intersolubility between isobutene and liquid ammonia molecules, so that the tert-butylamine is prepared. According to the present invention, by adding the catalyst, the dialkyl amine liquid film is rarely formed on the surface of the catalyst or the formed dialkyl amine liquid film is thinned so as to reduce the diffusion resistance of isobutene to the surface of the catalyst, increase the formation of positive carbon ions, improve the reaction speed, and improve the conversion rate of isobutene.

Description

technical field [0001] The invention relates to the technical field of olefin amination, in particular to a method for preparing tert-butylamine by amination of isobutene. Background technique [0002] Tertiar-Butylamine, English name Tertiar-Butylamine, molecular formula C 4 h 11 N, with a molecular weight of 76, is a colorless and transparent liquid with an ammonia odor. Tert-butylamine is an important organic intermediate, which has a wide range of uses in the production of medicine, synthetic rubber and pesticides. In medicine, tert-butylamine can be used as an intermediate raw material for the synthesis of various drugs. The main use of tert-butylamine is to produce sulfenamide-based rubber vulcanization accelerator NS. With the increasingly stringent environmental protection regulations and the popularization and application of domestic "green" rubber accelerator NS, the output of NS will increase, and the demand for tert-butylamine will also increase. As it rises,...

AI Technical Summary

Problems solved by technology

[0004] In the 1970s, foreign countries began to study the direct catalytic amination of isobutene to produce tert-butylamine, but it was not applied due to poor reaction selectivity and short catalyst life.

[0019] In summary, at present, in the reaction of preparing tert-butylamine from isobutene, some noble metal catalysts are used, and the cost is relatively high; conventional heteroatom molecular sieve catalysts modified by B, Ga, etc. have low activity, low conversion rate of isobutene per pass, and high reaction pressure. It leads to a great increase in equipment costs; borosilicate molecular sieve catalysts such as MCM, PSH, and SSZ with special structures have the characteristics of difficult synthesis, difficult preparation of templates used, and high prices, resulting in high costs and limiting industrial applications; Conventional silica-alumina molecular sieves or amorphous silica-alumina materials are used as catalysts. Because the acid center of the catalyst is too strong, it is easy to cause isobutylene to accumulate on the surface of the catalyst, resulting in carbon deposition and deactivation of the catalyst, which shortens the life of the catalyst and limits its continuous use.

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