PERSPECTIVE OF APPLICATION OF ZEOLITE CATALYSTS IN THE PROCESS OF ALKYLATION

摘要

The main aspects of development of isobutane alkylation with olefins on zeolite catalysts are presented in the article. The essence of the alkylation process is the introduction of alkyl group into the hydrocarbon molecule to produce highly branched paraffin hydrocarbons, having good antidetonation properties. Alkylat meets the technical, operational and environmental requirements of European standards for automotive fuel, therefore, for the development of Russian oil refining, increasing the production of alkylate is a promising direction, and the task of increasing the efficiency of the alkylation process is topical. Isobutane and butane-butylene fractions from the methyl tert-butyl ether (MTBE) production plants and catalytic cracking are used as raw materials.The stages of the carbocation mechanism of the alkylation of isobutane with olefins are considered in the article. A comparative analysis of the alkylation process on traditional (acidic) and zeolite catalysts is carried out. It has been found that the alkylation process using a zeolite catalyst eliminates toxic and aggressive volatile components, has a low level of production waste, has high activity, selectivity, stability. However, the cyclization, dehydrogenation, conjugated olefin oligomerization reactions have a significant effect on the deactivation of the solid acid catalyst. The main reason for the loss of activity of alkylation catalysts is the formation of alkylcyclopentadiene (ACPD) compounds. Methods for reducing the course of adverse reactions are described. An alkylation unit based on a zeolite catalyst has not already been introduced into Russian industry, but a lot of research has been done on this process by both foreign and domestic scientists. The development of alkylation technologies on solid-acid catalysts of leading foreign companies is presented. The costs for the realization of solid-acid alkylation are lower than for sulfuric and hydrofluoric plants. It is concluded that the use of solid superacid catalysts contributes to the improvement of alkylation technology.