Method for catalytically oxidizing cyclohexane

Abstract

The invention discloses a method for catalytically oxidizing cyclohexane, which is characterized in that cyclohexane, hydrogen peroxide and a catalyst are in contact for reacting, the mol ratio of the cyclohexane to the hydrogen peroxide is 0.5-8, the concentration of the catalyst in a reaction system is 0.005-0.1g / min, the reaction temperature is 40-150 DEG C, the catalyst is a titanium-silicon molecular sieve with an MFI structure, a hysteresis loop exits between an adsorption isotherm and a desorption isotherm of low-temperature nitrogen absorption of the molecular sieve, a crystalline grain is a single hollow crystalline grain or an aggregated crystalline grain formed by the aggregation of a plurality of hollow crystalline grains, the radial length of the cavity part of the hollow crystalline grains is 5-300nm, and the benzene adsorption capacity of the sample of the molecular sieve, measured under the conditions that the absorption time is 1h, the temperature is 25 DEG C and P / P0 is equal to 0.10, is at least 70mg / g. The method has the advantages of high selectivity of a target product and environment protection.

Description

technical field [0001] The invention relates to a method for catalytically oxidizing cyclohexane with titanium-silicon molecular sieve as catalyst and hydrogen peroxide as oxidant. Background technique [0002] Cyclohexanone and cyclohexanol are important chemical raw materials, widely used in the industries of fiber, synthetic rubber, industrial coating, medicine, pesticide and organic solvent. Especially due to the rapid development of the polyamide industry, the demand for cyclohexanone and cyclohexanol as intermediates for the preparation of nylon 6 and nylon 66 is more than 1 million tons per year all over the world. There are three main production process routes of cyclohexanone: cyclohexane liquid-phase oxidation method, phenol hydrogenation method and benzene partial hydrogenation method, among which cyclohexane oxidation method is the main process of industrial production of cyclohexanone, accounting for more than 90% , but the process is also considered to be one ...

AI Technical Summary

Problems solved by technology

However, some by-products will react with cobalt ions to form slag, which will be deposited on the inner wall of the equipment pipeline and cause blockage

[0007] In the research report of using ordinary titanium silicon molecular sieve as catalyst and hydrogen peroxide as oxidant to prepare cyclohexanone by oxidation of cyclohexane, the conversion rate of cyclohexane is low and the selectivity is poor.