Regeneration method of inactivated titanium silicon molecular sieve

Abstract

The invention discloses a regeneration method of an inactivated titanium silicon molecular sieve, specifically comprising the following steps of: mixing organic acid with an inactivated silicon molecular sieve and putting in a sealed reaction kettle, treating for 1 hour under the temperature of 40-150DEG C, continuously treating for three times, washing products by deionized water under normal temperature and normal pressure, drying, and roasting, so that the regenerated titanium silicon molecular sieve can obtained, wherein the lowest place in the reaction kettle contains the water quantity forming into saturated steam under a reaction condition, and the molar ratio of the inactivated titanium silicon molecular sieve, the organic acid to the water is 1.04: (0.002-0.5): (0.5-20). The regeneration method is low in energy consumption, and less in three-waste discharge, and the regenerated titanium silicon molecular sieve can be basically recovered to the activity level of the fresh catalyst.

Description

technical field [0001] The invention belongs to the field of petrochemical catalysts, and relates to a method for regenerating titanium-silicon molecular sieves. technical background [0002] In the 1980s, Taramasso et al. first discovered titanium-silicon molecular sieves with an MFI structure. Due to their excellent performance in catalytic oxidation reactions, they were widely used in the direct oxidation of hydrogen peroxide and organic substances, such as aromatic hydrocarbons, alcohols, In the ammoximation reaction of olefins, nitrogen-containing compounds and hydroxyl-containing compounds. Titanium-silicon molecular sieve is used as a catalyst. After running for a period of time in the oxidation reaction of organic matter, due to the introduction of impurities under the reaction conditions, by-products accumulate in the micropores to block the pores, the framework titanium species is converted into non-skeleton titanium species, and the active center is lost. Skeleto...

AI Technical Summary

Problems solved by technology

[0004] EP0100119 discloses two regeneration methods of titanium-silicon molecular sieves. One is high-temperature roasting at 550°C. The disadvantage is that it consumes a lot of energy and takes up equipment. The other is to use methanol or the solvent used in the reaction process. Washing, this regeneration method takes a long time for solvent washing, uses a large amount of solvent, and the effect is not ideal

CN101602011A discloses a method for regenerating titanium-silicon molecular sieves. The method uses acid and alkali solutions to treat molecular sieves. However, the operation process of this method is cumbersome and complicated, and a large amount of industrial waste water is produced by washing. The material consumption and energy consumption are high, and the environmental protection and economic efficiency are limited.

USP6878836B2 discloses a method for high-temperature washing and regeneration of methanol. The method is to wash deactivated titanium-silicon molecular sieves with methanol at a temperature above 100°C. The regenerated solvent can be used for a long time, and a constant hydrogen peroxide concentration can be obtained. conversion and selectivity of products, but the energy consumption of the method is relatively high