A kind of titanium silicon molecular sieve catalyst, preparation method and application thereof

Abstract

The invention discloses a titanium silicalite molecular sieve catalyst, which comprises 40 to 65 mass percent of titanium silicalite molecular sieve with a melt flow index (MFI) topological structure and 35 to 60 mass percent of aluminum oxide, wherein the aluminum oxide is made from aluminum hydroxide powder and aluminasol, and the side pressure breaking strength is 70 to 150N / cm. The catalyst is prepared by mixing the titanium silicalite molecular sieve with the MFI topological structure, aluminum hydroxide powder, aluminasol, a pore-forming agent, an extrusion assistant and water, kneading to obtain a formable plastomer, extruding the formable material in a strip extruder to form wet strip formed bodies, and drying and roasting the extruded strip formed bodies, wherein the total mass of the pore-forming agent and the extrusion assistant is 15 to 75 percent based on the mass of the titanium silicalite molecular sieve powder; and based on aluminum oxide, the mass ratio of the aluminum hydroxide powder to the aluminasol is (1-3):1. The catalyst is particularly suitable for catalyzing the epoxidation of 3-chloropropene and hydrogen peroxide for preparing epoxy chloropropane in a fixed bed reactor.

Description

technical field [0001] The invention relates to a high-strength titanium-silicon molecular sieve catalyst, its preparation method and its application in the epoxidation reaction of 3-chloropropene and hydrogen peroxide. Background technique [0002] U.S. Patent No. 4,833,260 discloses the highly selective synthesis of rings by the epoxidation of 3-chloropropene with hydrogen peroxide in the presence of a titanium-silicon molecular sieve (TS-1) catalyst with MFI topology and solvent methanol Oxychlorohydrin method to realize greening of epichlorohydrin synthesis process. Wherein said TS-1 catalyst can be TS-1 raw powder, also can be shaped TS-1 catalyst. When the original powder catalyst is used, it is very difficult to separate the catalyst from the liquid reaction product because its average particle diameter is only about 0.2 μm. [0003] The method to solve the difficulty in separating the titanium-silicon molecular sieve raw powder catalyst from the liquid product is t...

AI Technical Summary

Problems solved by technology

Mix TS-1 titanium silicate molecular sieve, nano-alumina, aluminum sol, porogen, extrusion aid and water to obtain a moldable product, extrude the moldable product with an extruder to obtain a wet strip-shaped product, dry and roast The extruded strip shaped body can be used to obtain a shaped catalyst, and the epoxidation reaction of 3-chloropropene and hydrogen peroxide can be carried out in a fixed bed reactor, and a conversion rate of hydrogen peroxide of 99.2% and an epoxy chlorine of 96.9% can be obtained. Propane selectivity, however, the mechanical strength of the catalyst is only 20-30N / cm 2 , it is difficult to meet the requirements of industrial fixed bed reactors

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