Preparation method and application of normal hydrocarbon hydroisomerization catalyst

Abstract

The invention relates to a preparation method and application of a normal hydrocarbon hydroisomerization catalyst. The preparation method comprises the following steps: mixing deionized water and a phosphorus source, adding an aluminum source, a silicon source and a microporous template agent, mixing evenly, then adding a mesoporous template agent, stirring to obtain sol, aging, adding a matrix, and conducting dynamic hydrothermal crystallization; washing, separating, drying and roasting the products to obtain a cascade hole SAPO-11 / gamma-Al2O3 composite; and impregnating a metal active component to the cascade hole SAPO11 / gamma Al2O3 composite material by an isopyknic impregnation method, and then airing at room temperature, drying and roasting to obtain the normal hydrocarbon hydroisomerization catalyst. The invention also provides the application of the catalyst prepared by the above method to a normal hydrocarbon isomerization reaction. The catalyst prepared by the preparation method provided by the invention has high normal hydrocarbon hydroisomerization conversion as well as excellent selectivity on double branch and multiple branch isomers.

Description

technical field [0001] The invention relates to a preparation method and application of a novel normal hydrocarbon hydroisomerization catalyst, belonging to the field of catalysts for petroleum refining. Background technique [0002] The hydroisomerization of normal hydrocarbons to branched alkanes is widely used in increasing the octane number of gasoline. The silicoaluminophosphate molecular sieve SAPO-n has a suitable one-dimensional pore structure, suitable acidity, good thermal stability and hydrothermal stability, and exhibits excellent catalytic performance in the hydroisomerization reaction of normal hydrocarbons , has been widely used. [0003] Chinese patent application CN1475304A discloses a catalyst for the hydroisomerization of long-chain normal hydrocarbons and its application method. The weight percentage of the catalyst is composed of 0.1-1.0% of precious metals and 20-79% of silicon and aluminum oxide gels. %, silicoaluminophosphate molecular sieve 20-79%....

AI Technical Summary

Problems solved by technology

[0009] The common disadvantage of the above technical solutions is that molecular sieves are directly used or molecular sieve-refractory oxides are kneaded and extruded under the action of a binder as a catalyst carrier for hydroisomerization, which greatly reduces the utilization of molecular sieves. rate, increasing the production cost of the catalyst

Among them, although the technical solution disclosed in Chinese patent application CN1488722A uses nano-Hbeta zeolite to shorten the residence time of the carbenium ion intermediate and reduces the carbon deposition amount of the catalyst, it cannot fundamentally solve the diffusion of the carbenium ion with a larger kinetic diameter problem, and there is also the problem that the synthesized nano-Hbeta molecular sieve is difficult to separate, which limits large-scale application; the technical solution disclosed in the Chinese patent application CN171074A uses acid solution to prepare the catalyst carrier, that is, the mesopore is produced by dealumination with acid, and the dredging The pores of the catalyst are improved, but the process of acid dealumination will cause the destruction of the pore structure of the catalyst support and reduce the acid content of the catalyst, which will also make the preparation process of the catalyst complex and increase the cost

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