Titanium-silicalite molecular sieve, method for preparing the same and method for preparing cyclohexanone oxime using the molecular sieve

Abstract

The present invention provides a titanium-silicalite molecular sieve and a method for preparing the same. The method includes the steps of preparing a mixture of a titanium source, a silicon source, a transition metal source, a template agent and water,heating the mixture to form a gel mixture,heating the gel mixture in a water bath,and calcining the gel mixture after the gel mixture in the water bath to form the titanium-silicalite molecular sieve. The present invention further provides a method for preparing cyclohexanone oxime by using the titanium-silicalite molecular sieve as the catalyst which results in high conversion rate, high selectivity and high usage efficiency of hydrogen peroxide.

Description

technical field [0001] The invention relates to a titanium-silicon molecular sieve and a preparation method thereof, in particular to a titanium-silicon molecular sieve with a transition metal and a preparation method thereof. Background technique [0002] Crystalline titanium-silicon molecular sieve catalyst is to introduce titanium atoms into the network structure of silica. The crystal form with MFI structure is TS-1 molecular sieve and the crystal form with MEL structure is TS-2 molecular sieve. It is widely used in hydrogen peroxide as Among the oxidation reactions of oxidants, among them, the manufacturing processes that have been commercially operated include cyclohexanone ammoximation and phenol hydroxylation. [0003] In industry, cyclohexanone oxime is an indispensable intermediate product in the process of producing caprolactam. The method for producing cyclohexanone oxime by using cyclohexanone, ammonia and hydrogen peroxide with titanium-silicon molecular sieve ...

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Problems solved by technology

[0003] In industry, cyclohexanone oxime is an indispensable intermediate product in the process of producing caprolactam. The method for producing cyclohexanone oxime by using cyclohexanone, ammonia and hydrogen peroxide with titanium-silicon molecular sieve as a catalyst has been disclosed in No. 4968842, In U.S. Patent No. 5227525, No. 5312987 and No. 6828459, when this method is adopted, the production is simple and does not require the intermediate product of acidic hydroxylammonium, but there is a problem in the above-mentioned methods, that is, the use efficiency of hydrogen peroxide is limited to 89 % to 90%, the efficiency of hydrogen peroxide can no longer be improved and the manufacturing cost will increase

[0004] In addition, U.S. Patent No. 5,290,533 and European Patent No. 226,258 disclose a synthesis method of transition metal-containing titanium-silicon molecular sieves, but the synthesis method is to first treat the iron source with ammonia water to produce hydroxide precipitation, and the precipitate After washing, neutralizing and filtering, it is dissolved in the template agent and then mixed with the titanium-silicon mixture, and then heated and replenished to produce molecular sieves through hydrothermal. This synthesis step is complicated and lengthy

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