A method for regenerating a deactivated molecular sieve catalyst and its application

Abstract

The invention discloses a regeneration method of a deactivated molecular sieve catalyst, comprising the following steps: (1) mixing the deactivated molecular sieve catalyst with a silica-alumina sol, and heat-treating at 200-260° C. for 12-24 hours to obtain a semi-finished product A; (2) contacting the semi-finished product A with a template agent for heat treatment, the treatment temperature is 130-200° C., the treatment time is 24-72 hours, and a semi-finished product B is obtained; (3) roasting the semi-finished product B to obtain a semi-finished product C; (4) contacting the semi-finished product C with an organic base to obtain a semi-finished product D; and treating the semi-finished product D at 130-220° C. for 4-72 hours to obtain a regenerated catalyst. The regeneration method of the present invention can fully restore the internal cavity of the molecular sieve crystal. The regenerated catalyst is used in the alkylation reaction to produce aromatics, and has the characteristics of high activity, high selectivity and high stability.

Description

Technical Field

[0001] The invention belongs to the technical field of catalytic chemistry and chemical engineering, and in particular relates to a regeneration method for a deactivated molecular sieve catalyst and application thereof. Background Art

[0002] Molecular sieve catalysts are commonly used catalysts in catalytic chemical reactions, such as alkylation to produce aromatics. Catalysts used in industry are generally molecular sieve catalysts. Molecular sieve catalysts have acidic catalytic active centers. As the reaction time progresses, the carbon deposits produced during the reaction will be deposited in the pores or surfaces of the catalyst, thereby blocking the microporous pores of the catalyst and covering the acidic active centers, resulting in a decrease in the catalytic performance of the catalyst. At the same time, the bulk density, total specific surface area, total pore volume and mechanical strength of the catalyst will also decrease to varying degrees. Especially for molecular sieve catalysts with cavities inside the crystals, during long-term operation, their cavities will also be damaged to varying degrees, thereby affecting the performance of the catalyst. Therefore, after the catalyst has been running for a certain period of time, when the performance of the catalyst has dropped to a certain extent, it needs to be regenerated.

[0003] CN105597842 B discloses a regeneration method for an ethylbenzene catalyst, wherein the regeneration process is as follows: treating the deactivated ethylbenzene catalyst with a 0.1-20.0wt% organic amine or organic ammonium solution for 2-20 hours, drying at 100-200°C in a nitrogen atmosphere for 2-10 hours, and calcining at a high temperature of 400-800°C in an air atmosphere for 2-10 hours, wherein the solid-liquid ratio of the deactivated catalyst to the organic amine or organic ammonium solution is (5-50):1, and the treatment temperature is 50-120°C. The regeneration method can only maintain the skeleton structure of the deactivated catalyst and increase some mesoporous channels to restore some performance of the ethylbenzene catalyst, but the method is not suitable for the regeneration of a molecular sieve catalyst containing cavities inside the crystal. The method cannot restore the cavities inside the molecular sieve crystal to the level of a fresh catalyst, and the bulk density, total specific surface area, total pore volume and mechanical strength of the catalyst are also difficult to restore to the level of a fresh catalyst.

[0004] Therefore, for molecular sieve catalysts with cavities inside, how to restore the cavity structure inside during the regeneration process becomes a technical problem faced in the regeneration process of molecular sieve catalysts with cavities. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention aims to provide a method for regenerating a deactivated molecular sieve catalyst, so that the internal cavity of the molecular sieve crystal can be fully restored through regeneration, and the activity, selectivity and stability of the regenerated catalyst can be maintained.

[0006] The first aspect of the present invention is to provide a method for regenerating a deactivated molecular sieve catalyst, comprising the following steps:

[0007] (1) mixing the deactivated molecular sieve catalyst and the silica-alumina sol, and heat treating the mixture at 200-260° C. for 12-24 hours to obtain a semi-finished product A;

[0008] (2) contacting the semi-finished product A with a template agent for heat treatment at a temperature of 130-200° C. for a treatment time of 24-72 hours to obtain a semi-finished product B;

[0009] (3) roasting the semi-finished product B to obtain the semi-finished product C;

[0010] (4) contacting the semi-finished product C with an organic base to obtain a semi-finished product D; treating the semi-finished product D at 130-220° C. for 4-72 hours to obtain a regenerated molecular sieve catalyst.

[0011] In the above technical solution, preferably, the molecular sieve catalyst is preferably a cavity-binderless molecular sieve catalyst, such as a cavity-binderless molecular sieve catalyst used for alkylation to produce aromatics. More preferably, the molecular sieve is a ZSM-5 or Beta molecular sieve catalyst.

[0012] In the above technical solution, preferably, the mass ratio of the deactivated molecular sieve catalyst to the silica-alumina sol in step (1) is (0.1-1):1.

[0013] In the above technical solution, preferably, the mixing process in step (1) is: mixing the deactivated molecular sieve catalyst and silica-alumina sol at 50-100° C. for 2-10 hours. The heat treatment in step (1) is preferably performed in a closed space.

[0014] In the above technical scheme, preferably, the silica-alumina sol described in step (1) is a silica-alumina sol obtained by contacting a silicon source, an aluminum source and water, and the molar ratios of the silicon source, the aluminum source and water are respectively, silicon source: aluminum source = (12-400): 1; water: silicon source = (3-6): 1; wherein the silicon source is calculated as SiO2, and the aluminum source is calculated as Al2O3.

[0015] In the above technical solution, preferably, the silicon source is one or more of silica sol, white carbon black and silicon powder; the aluminum source is one or more of aluminum sulfate, aluminum nitrate, aluminum chloride and aluminum isopropoxide.

[0016] In the above technical solution, preferably, the method for preparing the silica-alumina sol in step (1) is to stir a silicon source, an aluminum source and water in a closed space at a stirring temperature of 100-150° C. for 5-10 hours.

[0017] In the above technical solution, preferably, the template agent in step (2) is one or more of tetrapropylammonium hydroxide, tetraethylammonium hydroxide, ethylamine, n-butylamine, cyclohexylamine, and ethylenediamine.

[0018] In the above technical solution, preferably, the template in step (2) is a template aqueous solution with a mass concentration of 5-20wt%; preferably, the mass ratio of the semi-finished product A in step (2) to the template aqueous solution is (0.2-1):1.

[0019] In the above technical solution, preferably, the heat treatment described in step (2) is carried out in a closed space.

[0020] In the above technical solution, preferably, the roasting process in step (3) comprises: roasting the semi-finished product B at 250-550° C. in an air atmosphere for 2-5 hours, and controlling the organic matter mass content in the obtained semi-finished product C to be 0-6%.

[0021] In the above technical solution, preferably, the organic base described in step (4) is an organic base aqueous solution with a mass concentration of 10%-30%; preferably, the mass ratio of the organic base aqueous solution to the semi-finished product C is (1.5-20):1.

[0022] In the above technical solution, preferably, the organic base described in step (4) is a mixed aqueous solution of tetrapropylammonium hydroxide or tetraethylammonium hydroxide and at least two other different quaternary ammonium bases, and the structural formula of the other quaternary ammonium base is:

[0023]

[0024] Wherein R1, R2, R3 and R4 are each selected from one or more of n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, benzyl or phenethyl. R1, R2, R3 and R4 may be the same or different.

[0025] In the above technical solution, preferably, the mass ratio of the tetrapropylammonium hydroxide or tetraethylammonium hydroxide to the total amount of other quaternary ammonium bases is (2-8):1.

[0026] In the above technical solution, preferably, the mass proportion of each quaternary ammonium base in the other quaternary ammonium bases is 20%-60%.

[0027] In the above technical solution, preferably, in step (4), the semi-finished product D is treated at 130-220° C. for 4-72 hours, and then washed, dried and calcined to obtain a regenerated molecular sieve catalyst. Preferably, the drying conditions are as follows: the drying temperature is 100-150° C. and the drying time is 5-10 hours; the calcination conditions are as follows: the calcination temperature is 520-580° C. and the calcination time is 5-8 hours.

[0028] In the above technical solution, preferably, the molecular sieve catalyst is a molecular sieve catalyst for alkylation to produce aromatics, more preferably a ZSM-5 molecular sieve catalyst for alkylation to produce aromatics; preferably, the molecular sieve crystals in the catalyst contain cubic cavities of three sizes, and the area distribution range of the rectangles corresponding to the vertical projections of the three cubic cavities from top to bottom is 30-80nm respectively. 2 、350-1000nm 2 and 1500-3000nm 2 The proportions of the three types of cubic cavities are 55-70%, 25-35% and 5-10% respectively.

[0029] In the above technical solution, preferably, the bulk density of the ZSM-5 molecular sieve catalyst is 0.5-0.55 g·cm -3 Preferably, the total specific surface area of ​​the catalyst is 450-700m 2 ·g -1 , the total pore volume is 0.6-1.0cm 3 ·g -1 Preferably, the mechanical strength of the regenerated catalyst is 110-160 N / cm.

[0030] In the above technical solution, preferably, the molecular sieve catalyst for alkylation to produce aromatics is a Beta molecular sieve catalyst for alkylation to produce aromatics. Preferably, the molecular sieve crystals in the catalyst contain three kinds of nearly spherical cavities with size distributions, and the diameter distribution ranges of the circles corresponding to the vertical projections of the three cavities from top to bottom are within 10-30nm, 40-50nm and 60-90nm, respectively, and the proportions of the number of the three cavities are 20-40%, 50-75% and 5-10%, respectively.

[0031] In the above technical solution, preferably, the bulk density of the Beta molecular sieve catalyst is 0.52-0.58 g·cm -3 Preferably, the total specific surface area of ​​the catalyst is 700-850m 2 ·g -1 , the total pore volume is 0.9-1.2cm 3 ·g -1 Preferably, the mechanical strength of the catalyst is 60-120 N / cm.

[0032] In the above technical solution, preferably, the preparation method of the molecular sieve catalyst (such as the ZSM-5 molecular sieve catalyst for alkylation to produce aromatics) comprises the following steps:

[0033] (a) calcining the formed molecular sieve precursor in an air atmosphere at 250-400° C. for 2-5 hours to obtain a mixture E;

[0034] (b) The mixture E is contacted with a mixed organic base to obtain a mixture F, and the mixture F is treated at 150-220° C. for 4-24 hours, and then washed, dried and calcined to obtain a benzene alkylation catalyst.

[0035] In the above technical solution, preferably, in step (a), the calcination temperature and time are controlled so that the mass content of organic matter in the mixture E is 2wt.%-6wt.%, and the organic matter comes from the organic template in the molecular sieve synthesis raw material.

[0036] In the above technical solution, preferably, the mixed organic base in step (b) is an aqueous solution of the mixed organic base, and its mass concentration is 20%-30%.

[0037] In the above technical solution, preferably, the mass ratio of the mixed organic base aqueous solution and the mixture E in step (b) is (2-20):1.

[0038] In the above technical solution, preferably, the mixed organic base described in step (b) is a mixed aqueous solution of tetrapropylammonium hydroxide and other quaternary ammonium bases, and the structural formula of the other quaternary ammonium base is:

[0039]

[0040] Wherein R1, R2, R3 and R4 are each independently selected from any one of n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, benzyl and phenethyl. R1, R2, R3 and R4 may be the same or different.

[0041] In the above technical solution, preferably, the other quaternary ammonium bases contain at least three different quaternary ammonium bases.

[0042] In the above technical solution, preferably, the mass ratio of tetrapropylammonium hydroxide to the total amount of other quaternary ammonium bases is (2-5):1.

[0043] In the above technical solution, preferably, the mass proportion of each quaternary ammonium base in other quaternary ammonium bases is 20%-60%.

[0044] In the above technical solution, preferably, the treatment process in step (b) is carried out in a closed space.

[0045] In the above technical solution, preferably, the washing, drying and roasting in step (b) can be carried out by any conventional method. For example, the washing can be carried out with deionized water until the pH value of the solution is 7-7.5; the drying temperature is 90-200°C and the drying time is 4-12 hours; the roasting temperature is 500-600°C and the roasting time is 4-8 hours.

[0046] In the above technical solution, preferably, the preparation process of the molecular sieve precursor in step (a) comprises the following steps:

[0047] (1) contacting a template, a silicon source, a first aluminum source, and water to obtain a mixture A;

[0048] The molar ratios of the template agent, silicon source, first aluminum source and water are respectively: template agent: silicon source = (0.1-1.0): 1; silicon source: first aluminum source = (130-400): 1, water: silicon source = (5-10): 1, wherein the silicon source is calculated as SiO2, and the first aluminum source is calculated as Al2O3;

[0049] (2) contacting mixture A, silicon powder and a second aluminum source to obtain mixture B;

[0050] The ratios of the mixture A, silicon powder and the second aluminum source are as follows: the weight ratio of the mixture A to the silicon powder is (0.2-0.8):1; the molar ratio of the silicon powder to the second aluminum source is (130-400):1; the silicon powder is calculated as SiO2, and the second aluminum source is calculated as Al2O3;

[0051] (3) forming the mixture B to obtain a mixture C;

[0052] (4) contacting the mixture C with an alkali source to obtain a molecular sieve precursor D;

[0053] The weight ratio of the alkali source to the mixture C is (1.5-10):1.

[0054] In the above technical scheme, preferably, the template agent described in step (1) is a mixture of tetrapropylammonium hydroxide and tetrapropylammonium bromide, and the molar ratio of tetrapropylammonium hydroxide to tetrapropylammonium bromide is (2-5):1; the silicon source is one or more of silica sol, white carbon black, and tetraethyl silicate; and the first aluminum source is one or more of aluminum chloride, aluminum nitrate, and aluminum sulfate.

[0055] In the above technical scheme, preferably, in step (1), the process of obtaining mixture A by contacting the template, the silicon source, the first aluminum source and water is: stirring the template, the silicon source, the first aluminum source and water in a closed container, the stirring time is 10h-24h, and the stirring temperature is 80-120°C.

[0056] In the above technical solution, preferably, in step (2), the second aluminum source is one or more of aluminum chloride, aluminum nitrate and aluminum sulfate.

[0057] In the above technical solution, preferably, in step (3), mixture B is formed to obtain mixture C. Mixture C can be made into strips as needed, and its cross-section is circular, gear-shaped, clover-shaped, four-leaf clover-shaped or honeycomb-shaped. The diameter of mixture C is 0.6-4.0 mm and the length is 2-10 mm.

[0058] In the above technical solution, preferably, the alkali source in step (4) is one or more of ammonia water, ethylamine, ethylenediamine, n-butylamine, hexamethylenediamine and cyclohexylamine;

[0059] In the above technical solution, preferably, in step (4), the process of contacting the mixture C with the alkali source to obtain the molecular sieve precursor D is: treating the mixture and the alkali source in a closed space at 150-220° C. for 24-96 hours. The treated product is preferably washed and dried.

[0060] In the above technical solution, preferably, the preparation method of the molecular sieve catalyst for benzene alkylation (for example, the preparation method of the Beta molecular sieve catalyst for alkylation to produce aromatics) comprises the following steps:

[0061] (A) treating the molecular sieve with an acid and an ammonium salt solution to obtain a mixture E;

[0062] (B) The mixture E is contacted with a mixed organic base to obtain a mixture F, and the mixture F is treated at 130-150° C. for 24-72 hours, and then washed, dried, and calcined to obtain a molecular sieve catalyst for benzene alkylation.

[0063] In the above technical solution, preferably, the acid used for the acid treatment in step (A) is one or more of hydrochloric acid, sulfuric acid, and nitric acid, and the acid used for the acid treatment is an aqueous solution of the acid with a mass concentration of 0.1%-0.5%.

[0064] In the above technical solution, preferably, in step (A), the ammonium salt is one or more of ammonium chloride, ammonium nitrate and ammonium sulfate, and the ammonium salt solution is an aqueous solution with a mass concentration of 5%-20%.

[0065] In the above technical solution, preferably, the acid treatment condition in step (A) is 20-50° C. for 1-2 hours. The acid treatment is preferably carried out in a closed space.

[0066] In the above technical solution, preferably, the ammonium salt solution treatment condition in step (A) is 20-50° C. for 1-2 hours. Preferably, the ammonium salt solution treatment is carried out in a closed space.

[0067] In the above technical solution, preferably, the acid treatment or ammonium salt solution treatment is followed by washing and drying. The washing and drying can be carried out by conventional methods. For example, washing can be carried out by washing with deionized water until the pH value of the solution is 7-7.5. The drying conditions can be as follows: the drying temperature is 120-200°C and the drying time is 10-24 hours.

[0068] In the above technical solution, preferably, the weight ratio of the acid solution used for the acid treatment in step (A) to the molecular sieve is (1.5-10):1.

[0069] In the above technical solution, preferably, the weight ratio of the ammonium salt solution and the molecular sieve used in the ammonium salt solution treatment in step (A) is (1.5-10):1.

[0070] In the above technical solution, preferably, the mixed organic base in step (B) is a mixed organic base aqueous solution with a mass concentration of 10%-20%; the mass ratio of the mixed organic base aqueous solution to the mixture E is (1.5-10):1.

[0071] In the above technical scheme, preferably, the mixed organic base described in step (B) is a mixed alkali aqueous solution of tetraethylammonium hydroxide and at least two other different quaternary ammonium bases, and the other quaternary ammonium base has the structural formula:

[0072]

[0073] Wherein R1, R2, R3 and R4 are each independently selected from n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, benzyl or phenethyl, wherein R1, R2, R3 and R4 may be the same or different.

[0074] In the above technical solution, preferably, the mass ratio of tetraethylammonium hydroxide and the total amount of other quaternary ammonium bases in step (B) is (5-8):1.

[0075] In the above technical solution, preferably, the mass proportion of each quaternary ammonium base in other quaternary ammonium bases in step (B) is 20%-60%.

[0076] In the above technical solution, preferably, the washing, drying and roasting in step (B) can be carried out by any conventional method. For example, washing is carried out by washing with deionized water until the pH value of the solution is 7-7.5; the drying conditions can be as follows: the drying temperature is 120-200°C and the drying time is 10-24 hours; the roasting conditions can be as follows: the roasting temperature is 500-600°C and the roasting time is 5-10 hours.

[0077] In the above technical solution, the molecular sieve is preferably a binder-free molecular sieve.

[0078] In the above technical solution, the binder-free molecular sieve preparation process preferably comprises the following steps:

[0079] (i) contacting a first template, a silicon source, a first aluminum source and water to obtain a mixture A;

[0080] The molar ratios of the first template, silicon source, first aluminum source and water are respectively: first template: silicon source = (0.2-0.6): 1; silicon source: first aluminum source = (12-40): 1, water: silicon source = (10-15): 1, wherein the silicon source is calculated as SiO2, and the first aluminum source is calculated as Al2O3;

[0081] (ii) contacting mixture A, silicon powder and a second aluminum source to obtain mixture B;

[0082] The ratios of the mixture A, silicon powder and the second aluminum source are as follows: the weight ratio of the mixture A to the silicon powder is (0.6-1.0):1; the molar ratio of the silicon powder to the second aluminum source is (12-40):1; the silicon powder is calculated as SiO2, and the second aluminum source is calculated as Al2O3;

[0083] (iii) shaping the mixture B to obtain a mixture C;

[0084] (iv) contacting the mixture C, the fluoride and the second template to obtain a mixture D, and washing, drying and calcining the mixture D to obtain a binder-free molecular sieve;

[0085] The weight ratio of the fluoride to the mixture C is (0.01-0.03):1, and the weight ratio of the second template to the mixture C is (1.5-3):1.

[0086] In the above technical scheme, preferably, the first template described in step (i) is tetraethylammonium hydroxide; the silicon source is one or more of water glass, silica sol, white carbon black, and tetraethyl silicate; the first aluminum source is one or more of sodium aluminate, pseudo-boehmite, aluminum chloride, aluminum nitrate, and aluminum sulfate, and more preferably, the first aluminum source is one or more of sodium aluminate and pseudo-boehmite.

[0087] In the above technical scheme, preferably, the process of obtaining mixture A by contacting the first template, the silicon source, the first aluminum source and water in step (i) is: stirring the first template, the silicon source, the first aluminum source and water in a closed container, the stirring time is 5h-12h, and the stirring temperature is 130-170°C.

[0088] In the above technical solution, preferably, the silicon powder in step (ii) is silicon dioxide with a size distribution of 5-10 μm; the second aluminum source is a mixture of sodium aluminate and pseudo-boehmite, and the molar ratio of sodium aluminate and pseudo-boehmite is calculated as Al2O3: (1-2):1.

[0089] In the above technical solution, preferably, in step (iii), mixture B is formed to obtain mixture C. Mixture C can be made into strips as needed, and its cross-section is circular, gear-shaped, clover-shaped, four-leaf clover-shaped or honeycomb-shaped. The diameter of mixture C is 1.0-2.2 mm and the length is 2-4 mm.

[0090] In the above technical solution, preferably, the fluoride in step (iv) is one or more of ammonium fluoride, ammonium fluorosilicate, and hydrofluoric acid, and the second template is tetraethylammonium hydroxide;

[0091] In the above technical scheme, preferably, the process of contacting the mixture C, the fluoride and the second template to obtain the mixture D in step (iv) is: treating the mixture C, the fluoride and the second template at 130-170° C. in a closed space for 48-72 hours, and then washing, drying and calcining to remove organic matter.

[0092] In the above technical scheme, the washing, drying and roasting can be carried out by conventional methods. For example, the washing can be carried out with deionized water until the pH value of the solution is 7-7.5; for example, the drying conditions can be as follows: the drying temperature is 120-200°C and the drying time is 10-24 hours; the roasting conditions can be as follows: the roasting temperature is 500-600°C and the roasting time is 5-10 hours.

[0093] The second aspect of the present invention is to provide an application of the above regeneration method in the regeneration process of molecular sieve catalysts for alkylation to produce aromatics.

[0094] In the above technical scheme, the alkylation reaction to produce aromatics is a reaction in which raw aromatics and olefins are alkylated to produce substituted aromatics. The raw aromatics are one or more of benzene, toluene, ethylbenzene, n-propylbenzene, isopropylbenzene, n-butylbenzene, isobutylbenzene, and tert-butylbenzene, and the olefins are one or more of ethylene, propylene, n-butene, and isobutylene. The olefins may be a single component, multiple components, or other mixed gases containing the above olefins. Substituted aromatics are any one or more products generated by aromatics and olefins.

[0095] In the above technical scheme, the reaction operating conditions of the alkylation to produce aromatics are as follows: reaction temperature is 140-400°C, pressure is 0.1-5.0MPa, olefin mass space velocity is 0.1-10.0h -1 , the molar ratio of aromatic hydrocarbon 1 to olefin is 1-20.

[0096] The present invention has the following beneficial effects:

[0097] 1. The regeneration method of the deactivated molecular sieve catalyst of the present invention can fully restore the internal cavity of the molecular sieve crystal, and even restore it to the level of a fresh catalyst. At the same time, the bulk density, total specific surface area, total pore volume and mechanical strength of the catalyst are also well restored.

[0098] 2. The deactivated catalyst regeneration method of the present invention is preferably applicable to the regeneration process of the binder-free molecular sieve catalyst. The deactivated catalyst regeneration method of the present invention is particularly applicable to the regeneration process of the alkylation molecular sieve catalyst with a cavity to produce aromatics. The regenerated catalyst is used in the alkylation reaction, has high activity, good selectivity, long life, and is restored to the level of a fresh catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0099] Figure 1 The XRD spectrum of the molecular sieve catalyst regenerated in Example 1 of the present invention;

[0100] Figure 2 This is the XRD spectrum of the molecular sieve catalyst regenerated in Example 2 of the present invention;

[0101] Figure 3 This is the XRD spectrum of the molecular sieve catalyst regenerated in Example 3 of the present invention;

[0102] Figure 4 The XRD spectrum of the molecular sieve catalyst regenerated in Comparative Example 1 of the present invention;

[0103] Figure 5 This is the XRD spectrum of the molecular sieve catalyst regenerated in Comparative Example 2 of the present invention. DETAILED DESCRIPTION

[0104] The present invention is described in detail below in conjunction with specific implementation modes, but it should be understood that the protection scope of the present invention is not limited by the specific implementation modes.

[0105] The cavity size and distribution of the alkylation catalyst for producing aromatics in the present invention are obtained by analyzing TEM photos; the total specific surface area and total pore volume are obtained by nitrogen adsorption and desorption test; the mechanical strength is obtained by using an intelligent particle strength tester; the SiO2 / Al2O3 molar ratio is obtained by ICP test, and the organic matter content is tested by a thermal analyzer.

[0106] In the present invention, the XRD spectrum of the catalyst was obtained by using the Ultima IV X-ray powder diffractometer produced by Rigaku Corporation of Japan. The voltage was selected as 35 kV, the current was selected as 30 mA, and the scanning speed was 1°·min -1 . When scanning at a small angle, the 2θ angle is 1-5°, and when scanning at a wide angle, the 2θ angle is 5-80°

[0107] In the present invention, a G2F30 transmission electron microscope produced by FEI Company of the United States is used to obtain a TEM photograph of the catalyst. Before the test, the sample to be tested needs to be ground for 1-5 minutes, and then a large amount of ethanol is added to ultrasonically disperse it evenly. The suspension is added dropwise on a copper mesh, and the test can be carried out after the ethanol is completely evaporated.

[0108] In the present invention, the BEL-MAX specific surface and pore size analyzer produced by BELSORP of Japan is used to test the nitrogen adsorption and desorption isotherms of the catalyst at liquid nitrogen temperature, and the total specific surface area and total pore volume are calculated using the BET equation.

[0109] In the present invention, the mechanical strength of the catalyst is tested by using the DLIII intelligent particle strength tester of Dalian Penghui Technology Development Co., Ltd. The length of the tested catalyst is 5 mm and it is placed horizontally on the tester to test the maximum pressure the catalyst withstands when it is broken. After testing the crushing strength of 20 catalysts, the average value is taken.

[0110] In the present invention, the bulk density of the catalyst is measured using a 1000 ml graduated cylinder as the container, and the actual weight of the added catalyst (unit: g) is divided by the actual volume, and the unit is g·cm -3 .

[0111] In the present invention, Kontron Model S-35 ICP-AES analyzer is used to perform ICP testing to obtain silicon-to-aluminum ratio data.

[0112] In the present invention, TGA / DTA851 produced by Mettler-Toledo is used. e Thermal analyzer was used to test the organic content, with a heating rate of 10°C min -1 , the test temperature is 25℃ to 600℃, and the protective gas is N2.

[0113] [Example 1]

[0114] This example is used for regeneration of deactivated alkylation catalyst for producing aromatics. The fresh catalyst before deactivation is ZSM-5 molecular sieve catalyst (the catalyst is composed of 100wt% ZSM-5 molecular sieve). The molecular sieve crystal contains three cubic cavities with different sizes. The rectangular area distribution ranges of the three cubic cavities from top to bottom are 35-80nm respectively. 2 、400-950nm 2 and 1600-2850nm 2 The proportions of the three cubic cavities are 55%, 35% and 10% respectively. The total specific surface area of ​​the fresh catalyst is 575m 2 ·g -1 , the total pore volume is 0.84 cm 3 ·g -1 , mechanical strength is 140N / cm, bulk density is 0.53g·cm -3 .

[0115] The preparation process of the alkylation catalyst for producing aromatics is as follows:

[0116] 95 kg of tetrapropylammonium hydroxide (aqueous solution with a concentration of 40 wt %), 28 kg of tetrapropylammonium bromide, 60 kg of white carbon black, 3.2 kg of aluminum nitrate nonahydrate and 144 kg of water were mixed evenly and stirred at 100°C for 20 hours in a sealed container to obtain a mixture a1. 60 kg of the mixture a1, 120 kg of silicon powder and 6.5 kg of aluminum nitrate nonahydrate were contacted to obtain a mixture b1. B1 was extruded with an appropriate amount of deionized water to obtain a mixture c1 (c1 had a gear-shaped cross-section with a diameter of 1.5 mm and a length of 3-8 mm). 100 kg of hexamethylenediamine and 20 kg of the mixture c1 were treated at 180°C in a closed space for 48 hours, then washed with deionized water until the pH value was 7.0, and dried at 120°C for 6 hours to obtain a mixture d1. The mixture d1 was roasted at 320°C in an air atmosphere for 4 hours to obtain a mixture e1, and the mass content of organic matter in the mixture e1 was 3.8 wt.%. 15 kg of mixture e1 and 100 kg of an organic base solution with a mass concentration of 25% (the solution contains five organic bases, tetrapropylammonium hydroxide, tetra-n-pentylammonium hydroxide, tetra-n-hexylammonium hydroxide, mono-n-pentyltriphenylethylammonium hydroxide and di-n-hexyldiphenylmethylammonium hydroxide, with mass proportions of 75%, 5%, 5%, 7.5% and 7.5% respectively) are mixed uniformly to obtain mixture f1. Mixture f1 is treated at 170° C. for 12 hours in a closed space, and then washed with deionized water until the pH value of the solution is 7.1, dried at 150° C. for 8 hours, and calcined at 550° C. for 6 hours to obtain catalyst g1.

[0117] The specific regeneration process is as follows: 600 kg of white carbon black, 16.65 kg of aluminum sulfate and 900 kg of water are stirred at 120°C for 8 hours in a closed space to obtain a silica-alumina sol. Then 500 kg of deactivated alkylation catalyst for aromatics and 1000 kg of silica-alumina sol are first mixed at 80°C for 8 hours, and then heated at 220°C for 18 hours in a closed space to obtain a semi-finished product A1. Then 500 kg of semi-finished product A1 and 1000 kg of tetrapropylammonium hydroxide aqueous solution with a mass concentration of 10wt% are heated at 180°C for 48 hours in a closed space to obtain a semi-finished product B1. The semi-finished product B1 is roasted at 450°C in an air atmosphere for 4 hours to obtain a semi-finished product C1, and the mass content of organic matter in the semi-finished product C1 is 3.2%. 500 kg of semi-finished product C1 and 5000 kg of organic base solution with a mass concentration of 20% (the solution contains three organic bases, tetrapropylammonium hydroxide, dibutyl di-n-hexylammonium hydroxide and tri-n-pentyl monophenylethylammonium hydroxide, with the mass proportions of the three being 80%, 10% and 10% respectively) are mixed evenly to obtain semi-finished product D1. Semi-finished product D1 is treated at 170° C. for 20 hours in a closed space, and then washed with deionized water until the pH value of the solution is 7, dried at 120° C. for 8 hours, and calcined at 550° C. for 6 hours to obtain the regenerated catalyst E1 for alkylation to aromatics.

[0118] The XRD spectrum of the regenerated alkylation catalyst E1 is as follows: Figure 1 As shown in the figure, the typical MFI topological structure diffraction peak is a ZSM-5 molecular sieve catalyst. The molecular sieve crystals in this catalyst contain cubic cavities of three sizes. The area distribution range of the rectangles corresponding to the vertical projections of these three cubic cavities from top to bottom is 32-76nm. 2 、420-910nm 2 and 1700-2800nm 2 The proportions of the three cubic cavities are 58%, 34% and 8% respectively. Through testing, the total specific surface area of ​​the catalyst E1 for alkylation to aromatics after regeneration is 580m 2 ·g -1 , the total pore volume is 0.82cm 3 ·g -1 , mechanical strength is 141N / cm, bulk density is 0.53g·cm -3 .

[0119] [Example 2]

[0120] This embodiment is used for the regeneration of a deactivated alkylation catalyst for aromatics. The catalyst before deactivation is a ZSM-5 molecular sieve catalyst, which is composed of 100wt% ZSM-5 molecular sieve. The molecular sieve crystals in the fresh catalyst before deactivation contain cubic cavities of three sizes. The rectangular area distribution ranges of the three cubic cavities corresponding to the vertical projections from top to bottom are 32-78nm respectively. 2 、380-960nm 2 and 1500-2800nm 2 The proportions of the three cubic cavities are 55%, 35% and 10% respectively. The total specific surface area of ​​the fresh catalyst is 610m 2 ·g -1 , the total pore volume is 0.86 cm 3 ·g -1 , mechanical strength is 142N / cm, bulk density is 0.52g·cm -3 .

[0121] The preparation process of the alkylation to aromatics catalyst is as follows:

[0122] 135 kg of tetrapropylammonium hydroxide (aqueous solution with a concentration of 40 wt %), 88 kg of tetrapropylammonium bromide, 60 kg of white carbon black, 2.5 kg of aluminum nitrate nonahydrate and 180 kg of water were mixed evenly and stirred in a closed container at 120°C for 10 hours to obtain a mixture a2. 96 kg of the mixture a2, 120 kg of silicon powder and 4 kg of aluminum sulfate 18 water were contacted to obtain a mixture b2. B2 was extruded by adding an appropriate amount of deionized water to obtain a mixture c2 (the cross section of c2 was a four-leaf clover shape with a diameter of 1.2 mm and a length of 3-8 mm). 30 kg of n-butylamine and 20 kg of the mixture c2 were treated at 220°C in a closed space for 24 hours, then washed with deionized water until the pH value was 7.0, and dried at 150°C for 4 hours to obtain a mixture d2. The mixture d2 was roasted at 390°C in an air atmosphere for 4 hours to obtain a mixture e2. The mass content of organic matter in the mixture e2 was 3.0 wt.%. 10 kg of mixture e2 and 200 kg of organic base solution with a mass concentration of 20% (the solution contains four organic bases, tetrapropylammonium hydroxide, tetra-n-butylammonium hydroxide, mono-n-pentyltriphenylethylammonium hydroxide and di-n-hexyldiphenylmethylammonium hydroxide, with the mass proportions of the four being 80%, 10%, 5% and 5% respectively) are mixed uniformly to obtain mixture f2. Mixture f2 is treated at 200° C. for 24 hours in a closed space, and then washed with deionized water until the pH value of the solution is 7.3, dried at 200° C. for 4 hours, and calcined at 600° C. for 4 hours to obtain benzene alkylation catalyst g2.

[0123] The specific regeneration process is as follows: 600 kg of silicon powder, 51.23 kg of aluminum sulfate and 540 kg of water are stirred at 100°C for 10 hours in a closed space to obtain a silica-alumina sol. Then 500 kg of deactivated alkylation catalyst for aromatics and 500 kg of silica-alumina sol are first mixed at 50°C for 10 hours, and then heated at 200°C for 12 hours in a closed space to obtain a semi-finished product A2. Then 500 kg of semi-finished product A2 and 500 kg of a 20wt% n-butylamine aqueous solution are heated at 130°C for 72 hours in a closed space to obtain a semi-finished product B2. The semi-finished product B2 is roasted at 550°C in an air atmosphere for 2 hours to obtain a semi-finished product C2, and the mass content of organic matter in the semi-finished product C2 is 2.1%. 500 kg of semi-finished product C2 and 750 kg of organic base solution with a mass concentration of 30% (the solution contains four organic bases of tetrapropylammonium hydroxide, di-n-pentyl di-n-hexylammonium hydroxide, di-n-heptyl diphenylethyl ammonium hydroxide, and tri-n-pentyl monophenylethyl ammonium hydroxide, and the mass proportions of the four are 70%, 10%, 10% and 10% respectively) are mixed evenly to obtain semi-finished product D2. The semi-finished product D2 is treated at 220° C. for 4 hours in a closed space, and then washed with deionized water until the pH value of the solution is 7, dried at 150° C. for 5 hours, and calcined at 580° C. for 5 hours to obtain the regenerated binder-free alkylation catalyst E2 for aromatics.

[0124] The XRD spectrum of the regenerated alkylation catalyst E2 is as follows: Figure 2 As shown in the figure, the typical MFI topological structure diffraction peak is a ZSM-5 molecular sieve catalyst. The molecular sieve crystals in this catalyst contain cubic cavities of three sizes. The area distribution range of the rectangles corresponding to the vertical projections of these three cubic cavities from top to bottom is 35-76nm respectively. 2 、360-950nm 2 and 1600-3000nm 2 The proportions of the three cubic cavities are 65%, 25% and 10% respectively. Through testing, the total specific surface area of ​​the catalyst E2 for alkylation to aromatics after regeneration is 620m 2 ·g -1 , the total pore volume is 0.85cm 3 ·g -1 , mechanical strength is 148N / cm, bulk density is 0.52g·cm -3 .

[0125] [Example 3]

[0126] This embodiment is used to regenerate a deactivated alkylation catalyst for producing aromatics. The catalyst before deactivation is a Beta molecular sieve catalyst, which is composed of 100wt% Beta molecular sieve. The molecular sieve crystals in the fresh catalyst before deactivation contain cubic cavities with three size distributions, and the molecular sieve crystals contain nearly spherical cavities with three size distributions. The diameter distribution range of the circles corresponding to the vertical projections of these three cavities from top to bottom is within 11-25nm, 45-50nm and 75-85nm, respectively. The proportions of the number of the three cavities are 30%, 60% and 10%, respectively. The total specific surface area of ​​the fresh catalyst is 826m 2 ·g -1 , with a total pore volume of 1.15 cm 3 ·g -1 , mechanical strength is 98N / cm, bulk density is 0.54g·cm -3 .

[0127] The preparation process of the alkylation to aromatics catalyst is as follows:

[0128] 84.2 kg of tetraethylammonium hydroxide (35 wt% aqueous solution), 208.3 kg of tetraethyl silicate, 18 kg of sodium aluminate (Al2O3 mass content of 40%) and 180 kg of water were mixed evenly and stirred in a sealed container at 130°C for 12 hours to obtain a mixture a3. 120 kg of the mixture a3, 200 kg of silicon powder, 30 kg of sodium aluminate (Al2O3 mass content of 40%) and 18 kg of pseudo-boehmite (Al2O3 mass content of 70%) were contacted to obtain a mixture b3. Add an appropriate amount of deionized water to b3 and extrude to obtain a mixture c3 (c3 is cylindrical with a diameter of 1.8 mm and a length of 2-3 mm). 1 kg of ammonium fluoride, 150 kg of tetraethylammonium hydroxide and 100 kg of mixture c3 were treated at 130°C for 72 hours in a closed space, then washed with deionized water until the pH value was 7.5, dried at 150°C for 15 hours, and roasted at 550°C in an air atmosphere for 6 hours to obtain mixture d3. 100 kg of mixture d3 and 150 kg of 0.1% hydrochloric acid aqueous solution were treated at 20°C for 1 hour in a closed space, then the acid solution was poured out, and 150 kg of 5% ammonium nitrate salt solution was added and treated at 20°C for 1 hour in a closed space, then washed with deionized water until the pH value was 7.5, and dried at 150°C for 15 hours to obtain mixture e3. 50 kg of mixture e3 and 100 kg of organic base solution with a mass concentration of 20% (the solution contains three organic bases, tetraethylammonium hydroxide, di-n-butyldibenzhydrylammonium hydroxide and tri-n-hexylmonoethylammonium hydroxide, with the mass proportions of the three being 83%, 8% and 9% respectively) are mixed evenly to obtain mixture f3. Mixture f3 is treated at 130° C. for 72 hours in a closed space, and then washed with deionized water until the pH value of the solution is 7, dried at 120° C. for 24 hours, and calcined at 550° C. for 5 hours to obtain molecular sieve catalyst g3 for alkylation to aromatics.

[0129] The specific regeneration process is as follows: 600 kg of white carbon black, 85 kg of pseudo-boehmite and 1080 kg of water are stirred at 150°C for 5 hours in a closed space to obtain a silica-alumina sol. Then 500 kg of deactivated alkylation catalyst for aromatics and 5000 kg of silica-alumina sol are first mixed at 100°C for 2 hours, and then heated at 260°C for 24 hours in a closed space to obtain a semi-finished product A3. Then 500 kg of semi-finished product A3 and 2500 kg of tetraethylammonium hydroxide aqueous solution with a mass concentration of 5wt% are heated at 200°C for 24 hours in a closed space to obtain a semi-finished product B3. The semi-finished product B3 is roasted at 550°C in an air atmosphere for 5 hours to obtain a semi-finished product C3, and the mass content of organic matter in the semi-finished product C3 is 0%. 500 kg of semi-finished product C3 and 5000 kg of organic base solution with a mass concentration of 20% (the solution contains four organic bases, tetraethylammonium hydroxide, di-n-pentyl di-n-hexyl ammonium hydroxide, di-n-heptyl diphenylethyl ammonium hydroxide, and tri-n-pentyl monophenylethyl ammonium hydroxide, with the mass proportions of the four being 70%, 10%, 10% and 10% respectively) are mixed evenly to obtain semi-finished product D3. The semi-finished product D3 is treated at 150° C. for 70 hours in a closed space, and then washed with deionized water until the pH value of the solution is 7, dried at 130° C. for 5 hours, and calcined at 550° C. for 6 hours to obtain the regenerated catalyst E3 for alkylation to aromatics.

[0130] The XRD spectrum of the regenerated alkylation catalyst E3 is as follows: Figure 3 As shown, a typical Beta molecular sieve catalyst. The molecular sieve crystals in this catalyst contain cubic cavities of three sizes, and the molecular sieve crystals contain nearly spherical cavities of three sizes. The diameter distribution ranges of the circles corresponding to the vertical projections of these three cavities from top to bottom are within 12-18nm, 42-48nm and 65-80nm, respectively. The proportions of the three cavities are 35%, 55% and 10%, respectively. Through testing, the total specific surface area of ​​the regenerated alkylation aromatics catalyst G3 is 845m 2 ·g -1 , the total pore volume is 1.16cm 3 ·g -1 , mechanical strength is 95N / cm, bulk density is 0.55g·cm -3 .

[0131] [Comparative Example 1]

[0132] The deactivated alkylation catalyst for producing aromatics in Example 1 was regenerated with reference to the method of patent CN105597842 B. The specific process is as follows: after the deactivated molecular sieve catalyst in the reactor is unloaded, it is treated with a 15wt% tetrabutylammonium hydroxide solution for 20 hours, wherein the solid-liquid ratio of the deactivated catalyst to the tetrabutylammonium hydroxide solution is 40:1, and the treatment temperature is 110°C; then the catalyst is dried at 185°C for 10 hours under a nitrogen atmosphere; finally, the catalyst is calcined at 600°C for 10 hours under an air atmosphere to obtain a regenerated ethylbenzene catalyst D1.

[0133] The XRD spectrum of the regenerated binder-free alkylation catalyst D1 is as follows: Figure 4 As shown in the figure, the typical MFI topological structure diffraction peak is a ZSM-5 molecular sieve catalyst. The cavities inside the molecular sieve crystals in this catalyst are irregular in shape, and the boundaries between adjacent cavities are not clear. The area and number of the irregular two-dimensional figures corresponding to the vertical projection of the cavities from top to bottom are obviously different from those in Example 1. Through testing, the total specific surface area of ​​the catalyst D1 for the binder-free alkylation of aromatics after regeneration is 430m 2 ·g -1 , the total pore volume is 0.52cm 3 ·g -1 , mechanical strength is 85N / cm, bulk density is 0.48g·cm -3 .

[0134] [Comparative Example 2]

[0135] The deactivated alkylation catalyst for producing aromatics as in Example 3 was calcined in a calcining furnace at 580° C. for 6 hours to obtain a regenerated ethylbenzene catalyst D2.

[0136] The XRD spectrum of the regenerated alkylation catalyst D2 is as follows: Figure 5 The Beta molecular sieve catalyst is shown in the figure. The cavities inside the molecular sieve crystals in this catalyst are irregular in shape, and the boundaries between adjacent cavities are not clear. The area and number of the irregular two-dimensional figures corresponding to the vertical projection of the cavities from top to bottom are obviously different from those in Example 3. Through testing, the total specific surface area of ​​the catalyst D2 for alkylation to aromatics after regeneration is 610m 2 ·g -1 , the total pore volume is 0.71cm 3 ·g -1 , mechanical strength is 92N / cm, bulk density is 0.50cm 3 ·g -1 .

[0137] [Example 4]

[0138] The alkylation to aromatics catalysts E1, E2 and D1 regenerated in Examples 1 and 2 and Comparative Example 1 and the fresh catalysts in Examples 1 and 2 were respectively applied to the gas phase alkylation reaction of benzene and ethylene at a reaction temperature of 320°C, a pressure of 0.8 MPa, and an ethylene mass space velocity of 2.2 h -1 , under the condition that the molar ratio of benzene to ethylene was 4.0, the ethylene conversion rate, ethyl selectivity in the alkylation product and xylene content were tested. The test results are shown in Table 1 below.

[0139] Table 1 Results of gas phase alkylation of benzene and ethylene

[0140]

[0141] [Example 5]

[0142] The alkylation to aromatics catalysts E3 and D2 regenerated in Example 3 and Comparative Example 2 and the fresh catalyst in Example 3 were respectively applied to the alkylation reaction of benzene and ethylene at a reaction temperature of 180°C, a pressure of 3.5 MPa, and an ethylene mass space velocity of 0.6 h -1 , under the condition that the molar ratio of benzene to ethylene was 1.5, the ethylene conversion rate, ethyl selectivity and diethylbenzene content in the alkylation product were tested. The test results are shown in Table 2 below.

[0143] Table 2 Results of the alkylation of benzene and ethylene to produce aromatics

[0144]

[0145] The above describes the specific implementation of the present invention in detail, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the various technical features being combined in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for regenerating a deactivated molecular sieve catalyst, characterized in that: The following steps are involved: (1) mixing the deactivated molecular sieve catalyst and the silica-alumina sol, and heat treating the mixture at 200-260° C. for 12-24 hours to obtain a semi-finished product A; (2) The semi-finished product A is brought into contact with the template and subjected to heat treatment at a temperature of 130-200° C. for a time of 24-72 hours to obtain the semi-finished product B; (3) roasting the semi-finished product B to obtain the semi-finished product C; (4) contacting the semi-finished product C with an organic base to obtain a semi-finished product D; treating the semi-finished product D at 130-220° C. for 4-72 hours to obtain a regenerated molecular sieve catalyst; The molecular sieve catalyst is a binder-free molecular sieve catalyst with a cavity; The calcination process in step (3) comprises: calcining the semi-finished product B at 250-550° C. in an air atmosphere for 2-5 hours, and controlling the organic matter mass content of the semi-finished product C to be 0-6%; The organic base in step (4) is a mixed aqueous solution of tetrapropylammonium hydroxide or tetraethylammonium hydroxide and at least two other different quaternary ammonium bases, and the other quaternary ammonium base has the structural formula: Wherein R1, R2, R3 and R4 are each independently selected from one or more of n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, benzyl or phenethyl.

2. The method according to claim 1, characterized in that: In step (1), the mass ratio of the deactivated molecular sieve catalyst to the silica-alumina sol is (0.1-1):

1.

3. The method according to claim 1, characterized in that: The mixing process in step (1) is: mixing the deactivated molecular sieve catalyst and the silica-alumina sol at 50-100° C. for 2-10 hours.

4. The method according to claim 1, characterized in that: The silica-alumina sol described in step (1) is obtained by contacting a silicon source, an aluminum source and water, wherein the molar ratio of the silicon source, the aluminum source and water is respectively: silicon source: aluminum source = (12-400): 1; Water: silicon source = (3-6): 1; the silicon source is calculated as SiO2, and the aluminum source is calculated as Al2O3.

5. The method according to claim 1, characterized in that: The template agent in step (2) is one or more of tetrapropylammonium hydroxide, tetraethylammonium hydroxide, ethylamine, n-butylamine, cyclohexylamine, and ethylenediamine.

6. The method according to claim 1, characterized in that: The template in step (2) is an aqueous solution of the template with a mass concentration of 5-20wt%.

7. The method according to claim 6, characterized in that: In step (2), the mass ratio of the semi-finished product A to the template aqueous solution is (0.2-1):

1.

8. The method according to claim 1, characterized in that: The organic base described in step (4) is an organic base aqueous solution with a mass concentration of 10%-30%.

9. The method according to claim 8, characterized in that: In step (4), the mass ratio of the organic alkali aqueous solution to the semi-finished product C is (1.5-20):

1.

10. The method according to claim 1, characterized in that: The mass ratio of the tetrapropylammonium hydroxide or tetraethylammonium hydroxide to the total amount of other quaternary ammonium bases is (2-8):

1.

11. The method according to claim 10, characterized in that: The mass proportion of each quaternary ammonium base in the other quaternary ammonium bases is 20%-60%.

12. The method according to claim 1, characterized in that: The molecular sieve catalyst is a molecular sieve catalyst for preparing aromatic hydrocarbons by alkylation.

13. The method according to claim 12, characterized in that: The molecular sieve catalyst is a ZSM-5 molecular sieve catalyst.

14. The method according to claim 12, characterized in that: The molecular sieve crystals in the catalyst contain cubic cavities with three sizes of distribution inside, and the area distribution range of the rectangles corresponding to the vertical projections of the three cubic cavities from top to bottom is 30-80 nm. 2 , 350-1000 nm 2 and 1500-3000 nm 2 The proportions of the three types of cubic cavities are 55-70%, 25-35% and 5-10% respectively.

15. The method according to claim 1, characterized in that: The molecular sieve catalyst is a Beta molecular sieve catalyst.

16. The method according to claim 15, characterized in that: The molecular sieve crystals in the catalyst contain nearly spherical cavities with three size distributions. The diameter distribution ranges of the circles corresponding to the vertical projections of the three cavities from top to bottom are respectively within 10-30 nm, 40-50 nm and 60-90 nm, and the proportions of the three cavities are respectively 20-40%, 50-75% and 5-10%.

17. Use of the regeneration method according to any one of claims 1 to 16 in the regeneration process of molecular sieve catalysts for alkylation to aromatics.

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