Method of using modified molecular sieve catalyst in isobutane catalytic cracking

Abstract

The invention discloses a method of using modified molecular sieve catalyst in isobutane catalytic cracking and belongs to the technical field of catalysts. The method includes the following steps: conducting full negative pressure degassing purification treatment on a molecular sieve, adopting a negative pressure deposition-precipitation method to load a gold precursor to a molecular sieve carrier, and obtaining an even and high-dispersion small particular supported gold catalyst. The molecular sieve is a high-silica zeolite molecular sieve, the supported gold catalyst obtained by the deposition-precipitation method under the condition of negative pressure is beneficial for purifying the inner surface, the outer surface and a duct of the molecular sieve, and Au can easily enter the duct of the molecular sieve to achieve high dissipation. By means of the method, dehydrogenation is conducted on isobutane to produce olefin under double functions of metal and a carrier, the olefin obtains a proton at an acid center to form a carbonium ion, and the carbonium ion conducts polymer lysis to generate a corresponding olefin.

Description

technical field [0001] The invention belongs to the technical field of catalysts, and relates to the application of a modified molecular sieve catalyst in the catalytic cracking reaction of isobutane. Background technique [0002] Ethylene, propylene and isobutylene produced by catalytic cracking and steam cracking units in refining and chemical enterprises are very important polymer monomers. At the same time, isobutene is also used in the synthesis of MTBE. However, due to the increasing depletion of petroleum resources, there are limitations in increasing the production of these useful olefins simply by expanding the amount of petroleum processing. On the other hand, in some places in the world such as China, the relative surplus of isobutene produced by catalytic cracking units needs to be developed and utilized urgently. The efficient conversion of isobutane into important chemical raw materials such as ethylene, propylene and isobutene through cracking reaction is ve...

AI Technical Summary

Problems solved by technology

When ZSM-5 is used as a carrier, only supported gold catalysts with gold particles of 40-50nm can be obtained, and Au / ZSM-5 catalysts with smaller particles cannot be obtained