In-situ regeneration method for molecular sieve catalyst

Abstract

The invention discloses an in-situ regeneration method for a molecular sieve catalyst, which is characterized by comprising the following technology steps of: (1) purging the inactivated molecular sieve catalyst by using a mixture of air, nitrogen and light hydrocarbons to remove a reactant; (2) after the gas purging, purging by using vapor of a mixture of water, methanol, ethanol and propanol; (3) supplementing nitrogen until a regeneration pressure reaches 0.5-5 MPa; adding into a regeneration mixed solution, wherein an oxidizing substance in the mixed solution is peroxide, a solvent is a mixture of alcohol and water, a regeneration temperature is 30-140 DEG C, a mass airspeed is 0.5-5 h<-1>, and a regeneration time is 2-20 hours; (4) purging the regenerated molecular sieve catalyst by using vapor of a mixture of water and alcohol; and (5) after the vapor purging is completed, purging by using mixture of air and hydrocarbons.

Description

technical field [0001] The present invention relates to the technical field of catalysis, and is an in-situ regeneration method for molecular sieve catalysts. More specifically, the present invention relates to an in-situ regeneration method suitable for mildly deactivated catalysts, specifically referring to oxidation reactions involving titanium-silicon catalysts. , the alkylation reaction of reforming aromatics to remove olefins, the synthesis reaction of long-chain alkylbenzene and the reaction process of small molecule alkylbenzene. Background technique [0002] The molecular sieve catalyst used in the refining and chemical industry will gradually lose its activity after a period of operation, which is caused by the accumulation of by-products in the pores of the molecular sieve to block the pores. Such by-products are generally divided into two types. One is that the generated macromolecular products cannot be diffused due to the pore diffusion effect, and the other is...

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Problems solved by technology

[0008] Patent CN 101439299A uses a mixed solution of hydrogen peroxide and formic acid to treat deactivated titanium-silicon molecular sieve catalysts at 40-120°C. The mass ratio of hydrogen peroxide to organic acid compounds is 1-8:1. The method requires the reaction to be Liquid phase, and the concentration of hydrogen peroxide is relatively high, so there are many difficulties in application at high temperature

[0009] The above-mentioned methods all need to remove the catalyst from the reaction system, which increases the consumption, and requires an additional impregnation device, which is difficult to realize