Aromatic hydrocarbon refining catalyst regeneration method and regenerated catalyst and application

Abstract

The present invention discloses a regeneration method of an aromatic hydrocarbon refining catalyst, a regenerated catalyst and an application thereof. The regeneration method comprises: roasting an aromatic hydrocarbon refining catalyst containing carbonaceous sediment to be regenerated in an oxygen-containing atmosphere not higher than 450°C; then sequentially mixing with a first solution for a first ultrasonic treatment, mixing with a second solution for a second ultrasonic treatment, and then roasting in an oxygen-containing atmosphere at a temperature lower than the above roasting temperature by more than 10°C to obtain a regenerated catalyst. The regenerated catalyst obtained by the regeneration method has a catalytic performance that can surpass that of a fresh catalyst, and in particular can significantly extend the single-cycle service life and total life of the regenerated catalyst.

Description

Technical Field

[0001] The invention relates to the field of molecular sieve catalyst regeneration, and more specifically to a method for regenerating an aromatic hydrocarbon refining catalyst. Background Art

[0002] In the application of molecular sieve catalysts, a certain amount of coking will generally be formed after the catalytic reaction occurs in contact with organic matter under reaction conditions, especially under non-oxidative reaction conditions. In the production process of aromatic products, aromatics from reforming or other reactions generally contain a variety of trace olefins, mainly olefins with carbon numbers of seven or less, carbon eight olefins, and olefin compounds with carbon numbers of nine or more, which must be removed before they can become the final product. Generally, bleaching clay or molecular sieve catalysts are used for non-hydrogen liquid phase deolefination treatment, that is, olefins and aromatics undergo alkylation reaction to remove olefins. The diffusion rate of the macromolecular products generated is much lower than the gas phase diffusion rate. When the residence time in the catalyst is too long, it is easy to cause the catalyst to further react to generate overly large polyaromatic ring polymers, thereby gradually forming a large amount of coking products, resulting in blockage of the pores, and the catalyst gradually deactivates and needs to be regenerated. However, the current regeneration technology of molecular sieve catalysts is not perfect. Conventionally, the catalyst is stopped and unloaded and then coked and removed. The performance of most catalysts is seriously reduced after regeneration.

[0003] In order to restore the activity of the catalyst, the coke in the catalyst needs to be removed. There are currently three main removal and regeneration methods. The first is the solvent dissolution regeneration method, which uses solvent dissolution to remove part of the coke from the catalyst; the second is the charring method, which removes the catalyst from the reactor and then chars it, and roasts the coke in an oxygen-containing atmosphere or medium to form carbon monoxide, carbon dioxide and other gases that are discharged, thereby removing the coke in the catalyst; the third is the resurrection treatment method after full charring, in which the charred catalyst is revived by active repair, crystallization, loading of effective active components, etc., to restore its original activity.

[0004] The first solvent dissolution regeneration method is to dissolve the catalyst containing coke after the reaction with an organic solvent to restore some of the performance. For example, in the method disclosed in CN104437617A, a certain amount of carbon-deactivated catalyst is taken, and the aromatic deolefination catalyst or alkylbenzene synthesis catalyst is reformed and placed in a pressure-resistant autoclave. Then, a solvent containing a fatty alcohol polyoxyethylene ether penetrant is added in a certain proportion, and the mixture is filtered and dried after treatment at 50 to 350°C, and then roasted to remove coke. CN112642476A adopts an in-situ decoking method, including contacting the soluble coke material with the catalyst after the aromatic deolefination refining reaction; and dissolving the mixture with a mixture of one or more aliphatic hydrocarbons or oxygen-containing organic compounds. The in-situ regeneration method of the molecular sieve catalyst adopted in CN102151589A is to first purge with a gas such as nitrogen, water, methanol, ethanol, propanol mixture, etc., and then regenerate with a regeneration mixed solution containing peroxide, the solvent is alcohol and water, at a certain temperature, pressure and air velocity, and the regenerated molecular sieve catalyst is switched to water and alcohol mixture steam purge, and then purge with a mixture of air and hydrocarbons. This method adds a polar solvent mixture for extraction ex situ regeneration. Although the catalyst activity loss is small, the activity cannot be fully restored, and the regeneration process is complicated, the safety and environmental protection requirements are high, the waste liquid treatment requirements are high, and a special regeneration device needs to be established separately, which is costly and has low utilization rate.

[0005] The second charring method is to use high temperature and oxygen-containing gas to calcine and revive. It is easy to operate, but the high temperature causes a permanent partial loss of catalyst activity. US4202865 regenerates by continuously or periodically introducing low concentrations of oxygen into the catalyst bed and hydrotreating hydrocarbon fuels at the same time. At low oxygen concentrations, the carbon deposits on the catalyst are burned off without damaging the catalyst activity and will not significantly affect the hydrotreating process, but the equipment requirements are high and the cost is also high. In order to achieve a better charring and decoking effect, CN03137913.3 discloses a regeneration method, in which the deactivated catalyst is treated in an acidic solution with a pH ≤ 3, and then dried and calcined to complete the regeneration of the catalyst, but this method does not solve the problem of decreased catalytic activity caused by the dissolution of the skeleton of the deactivated catalyst. CN102405106A achieves better regeneration performance by controlling the amount of charring. After the catalyst after the aromatic material reaction cokes is regenerated, there is 0.5 to 3.0wt% coked carbon, which reduces the regeneration cost and improves the regeneration efficiency. CN102836743A discloses a multi-stage regeneration method for a molecular sieve catalyst, which includes subjecting the molecular sieve catalyst to be regenerated to constant temperature roasting at 300-750°C in multiple stages, so that the carbon deposits in the molecular sieve catalyst to be regenerated are decomposed into CO2 in small amounts and multiple times, but a certain loss of catalyst activity cannot be avoided.

[0006] The third is to char the deactivated catalyst and then further treat it to revive the reaction activity of the catalyst. For example, CN102513152A discloses a regeneration method for a titanium silicon molecular sieve catalyst, in which the deactivated catalyst is charred and roasted, and then secondary crystallized together with a crystallization solution (an aqueous solution containing one or more substances in ammonium salts, ammonia and organic amines, supplemented with a titanium source), hydrothermally crystallized at 130 to 190 ° C and sealed autogenous pressure for 12 to 120 hours, and then washed and dried to prepare a regenerated titanium silicon molecular sieve. The activity of the regenerated titanium silicon molecular sieve can reach or even exceed the level of a fresh titanium silicon molecular sieve catalyst. CN111686788A removes organic matter from the discarded molecular sieve catalyst by roasting, and then puts the waste solid catalyst, silicon source, guide agent and other materials into a reactor for crystallization according to a certain ratio requirement. After the end, the product is filtered, washed and dried to obtain a regenerated molecular sieve catalyst. This method does not destroy the structure of the original formed catalyst, and the crystallinity and specific surface area of ​​the regenerated product are greatly improved, but the performance of the original catalyst will change, and repeatability and controllability are more difficult. In CN112657549A, the burnt molecular sieve catalyst is modified with elements such as titanium and zirconium, and the resulting regenerated catalyst has high activity and good regeneration performance, which mainly solves the problem of low activity and poor regeneration performance of industrial catalysts after regeneration. However, the performance modification of the secondary regenerated catalyst is complex, the safety and environmental protection requirements are high, and the cost is high.

[0007] In summary, how to regenerate the catalyst for reforming aromatics after coking by a low-cost, simple and effective method without reducing the activity is a difficult problem in the operation of non-hydrogenation deolefination catalysts. Summary of the invention

[0008] In order to solve the problem that the deactivated aromatics refining catalyst (deolefination catalyst) in the prior art cannot be treated and needs to be landfilled, resulting in the problem that the hazardous waste problem cannot be solved, and the regeneration temperature is too high during the regeneration process, which destroys the activity of the catalyst and reduces the life of the catalyst after regeneration, the present invention provides a new regeneration method for aromatics refining catalyst. The method can improve the performance of the catalyst, greatly extend the single-cycle service life and total life of the regenerated catalyst, and can be used in actual production.

[0009] The first aspect of the present invention provides a method for regenerating an aromatics refining catalyst, comprising:

[0010] (1) calcining the aromatics refining catalyst containing carbonaceous deposits to be regenerated in an oxygen-containing atmosphere at a temperature not greater than 450° C.;

[0011] (2) subjecting the mixture of the catalyst treated in step (1) and the first solution to a first ultrasonic treatment, wherein the pH value of the first solution is 7 to 10;

[0012] (3) subjecting the mixture of the catalyst treated in step (2) and the second solution to a second ultrasonic treatment, wherein the pH value of the second solution is 4 to 7 and is not 7;

[0013] (4) The catalyst treated in step (3) is calcined in an oxygen-containing atmosphere at a temperature 10° C. lower than the calcination temperature in step (1) to obtain a regenerated catalyst.

[0014] Furthermore, the aromatics refining catalyst is a molecular sieve catalyst. The molecular sieve is one or more of a ten-membered ring or twelve-membered ring molecular sieve containing silicon-aluminum oxide or a molecular sieve containing silicon-phosphorus-aluminum oxide; wherein the ten-membered ring or twelve-membered ring molecular sieve containing silicon-aluminum oxide includes at least one of ZSM-5, MOR, BETA, Y molecular sieve, MCM-22, MCM-56, and ZSM-11; the molecular sieve containing silicon-phosphorus-aluminum oxide includes at least one of SAOP-11 and SAPO-34. The catalyst may also contain a binder. Based on the mass of the catalyst, the mass content of the molecular sieve is 30% to 95%.

[0015] Furthermore, based on the mass of the aromatics refining catalyst containing carbonaceous deposits to be regenerated, the mass content of carbon is above 0.1%, preferably, the mass content of carbon is above 2.0%, and more preferably, the mass content of carbon is above 3.0%.

[0016] Furthermore, the aromatics refining catalyst of the carbonaceous sediment to be regenerated is a catalyst deactivated after the de-olefination reaction of the aromatics-rich feedstock containing olefin impurities. The aromatics-rich feedstock containing olefin impurities can be derived from at least one of reforming oil, deheptane bottoms after isomerization reaction, and aromatics material after extraction. The aromatics-rich feedstock containing olefin impurities has an olefin content of 100 to 3800 mgBr / 100g in terms of bromine index.

[0017] Furthermore, in step (1), preferably, the calcination temperature is 200-450°C, preferably 240-450°C, more preferably 280-450°C, and the calcination time is 0.5-100h, preferably 0.5-20h. The calcination atmosphere in step (1) is an oxygen-containing atmosphere, such as air, or a mixed gas with an oxygen content of not less than 5wt%, in which the other gas may be nitrogen.

[0018] Furthermore, after the treatment in step (1), the carbon deposit removal rate is more than 50%, and after the treatment in step (3), the total carbon deposit removal rate is more than 70%; further, after the treatment in step (1), the carbon deposit removal rate is more than 70%, and after the treatment in step (3), the total carbon deposit removal rate is more than 80%.

[0019] Further, in step (2), the first solution is a solution containing a Group IA element and / or ammonium ions, for example, the first solution is a solution containing a Group IA hydroxide, or the first solution is a mixed solution containing a Group IA hydroxide and a Group IA salt, wherein the salt is one or more of nitrates, sulfates, halides, phosphates, and water-soluble organic acid salts. The Group IA element may be at least one of sodium, potassium, and lithium. For another example, the first solution is ammonia water, or the first solution is a mixed solution of ammonia water and an ammonium salt, wherein the salt is one or more of nitrates, sulfates, halides, phosphates, and water-soluble organic acid salts. In the first solution, the mass concentration of the Group IA salt and / or the ammonium salt is 0.1% to 20%.

[0020] Furthermore, in step (2), the first ultrasonic treatment conditions are as follows: the ultrasonic power density is 0.1 to 10 W / cm 2 The processing time is 0.1 to 100 hours, the liquid-to-solid mass ratio is 0.6 to 100, and the temperature is 30 to 100°C.

[0021] Furthermore, in step (2), preferably, the pH value of the first solution is 7.0 to 9.0 and is not 7.0, and more preferably 7.5 to 9.0. The ultrasonic power density is 0.2 to 5 W / cm 2 The processing time is 0.5 to 20 hours, the liquid-to-solid mass ratio is 2 to 12, and the temperature is 40 to 70°C.

[0022] Furthermore, in step (3), the second solution is an inorganic acid solution, and the acid is selected from one or more of sulfuric acid, hydrogen halide, nitric acid, phosphoric acid, and halogen acid.

[0023] Furthermore, in step (3), the second ultrasonic treatment conditions are as follows: the ultrasonic power density is 0.1 to 10 W / cm 2 The processing time is 0.1 to 100 hours, the liquid-to-solid mass ratio is 0.6 to 100, and the temperature is 30 to 100°C.

[0024] Furthermore, in step (3), preferably, the pH of the second solution is 4.0 to 6.5, and the ultrasonic power density is 0.2 to 5 W / cm 2 The processing time is 0.5 to 40 hours, the liquid-to-solid mass ratio is 2 to 20, and the temperature is 40 to 70°C.

[0025] Furthermore, the calcination temperature in step (4) is lower than the calcination temperature in step (1) by more than 40°C, and the calcination time is 0.5 to 100 hours, preferably 0.5 to 20 hours. Preferably, the calcination temperature in step (4) is above 150°C, preferably above 200°C, and more preferably above 240°C. The calcination atmosphere in step (4) is an oxygen-containing atmosphere, such as air, or a mixed gas with an oxygen content of not less than 5wt%, in which the other gas may be nitrogen.

[0026] Furthermore, the number of times of the first ultrasonic treatment in step (2) is 1 to 4 times.

[0027] Furthermore, the second ultrasonic treatment in step (3) is performed 1 to 4 times.

[0028] Furthermore, the catalyst after ultrasonic treatment in step (2) and step (3) may be washed, and the washing may be done with deionized water.

[0029] The second aspect of the present invention provides a regenerated catalyst prepared by the above regeneration method.

[0030] The third aspect of the present invention provides the use of the above-mentioned regenerated catalyst in the deolefination of aromatics refining.

[0031] Furthermore, the raw material for the aromatics refining and de-olefination reaction is an aromatics-rich raw material containing olefin impurities, such as reforming oil, wherein the olefin content calculated by bromine index is 100 to 3800 mgBr / 100g.

[0032] Furthermore, the reaction conditions for the aromatics refining and deolefination are as follows: pressure 0.5-5.0 MPa, temperature 130-260°C, volume space velocity 0.5-16 h -1 .

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. Aromatic hydrocarbon refining catalysts are usually regenerated by burning in the air. Since the burning temperature is high and a large amount of heat is generated, a large amount of skeleton aluminum of the molecular sieve will be removed, resulting in permanent loss of acidity and collapse of the pore structure. After extensive research, the inventors found that a large part of the coke is first removed at a relatively low temperature, and then the remaining coke is separated from the skeleton through the first ultrasonic treatment and the second ultrasonic treatment. At the same time, some non-skeleton structures in the original molecular sieve can also be removed, and then calcined at a lower temperature, so as to achieve the molecular sieve while removing carbon and maintaining a good skeleton structure and improving acid performance. The regeneration method of the present invention effectively overcomes the problem of catalyst deactivation after regeneration, and the regenerated catalyst obtained by the regeneration method of the present invention has a catalytic performance that can surpass that of a fresh catalyst, especially it can greatly extend the single-cycle service life and total life of the regenerated catalyst.

[0035] 2. The regeneration method of the present invention has a low roasting temperature, and the roasting exotherm is easy to control. In addition, the liquid phase ultrasonic treatment conditions are mild and the operation is simple, which effectively ensures the repeatability and universality of the process and is suitable for industrial promotion and application. DETAILED DESCRIPTION

[0036] The present invention will be further described below by way of examples.

[0037] In the present invention, the carbon content in the aromatic hydrocarbon refining catalyst containing carbonaceous sediment to be regenerated is measured by an infrared carbon content measuring instrument.

[0038] Example 1

[0039] The reforming oil with a mass content of 0.3% non-aromatics, 0.3% toluene, 55.1% C8 aromatics, 37.2% C9 aromatics, 7.1% C10 aromatics and above, and an olefin content of 1210mgBr / 100g calculated by bromine index, is heated at 2.8MPa and 10h -1 , entering into a deolefination reactor containing 10.0 g Y molecular sieve catalyst at 190°C, and reacting for 202 hours before the outlet bromine index reaches above 150 mg Br / 100 g. After stopping, the catalyst is purged at 120°C for 20 hours to obtain a catalyst containing carbon deposits, wherein the mass content of the carbon deposits in terms of carbon is 15%.

[0040] The catalyst containing carbon deposits was first heated to 400°C at 2°C / min in an air atmosphere and then kept at this temperature for 5 hours, with the remaining carbon content being 7.4%. The first ultrasonic treatment was then performed, wherein the first solution used was a solution containing sodium hydroxide and sodium sulfate (wherein the mass concentration of sodium sulfate was 2%), the pH value of the first solution was 8.0, and the ultrasonic power density was 0.8 W / cm 2 The mixture was treated for 10 h at a liquid-to-solid mass ratio of 6 and a temperature of 60°C. The mixture was filtered and washed, and then subjected to a second ultrasonic treatment. The second solution used was a nitric acid solution with a pH value of 4.5. The ultrasonic power density was 0.5 W / cm 2 The catalyst was treated for 6 hours at a liquid-to-solid mass ratio of 5.0 and a temperature of 90°C, filtered and washed; the second ultrasonic treatment was repeated once. The catalyst was then dried at 120°C for 10 hours, and then heated to 380°C at a rate of 2°C / min for 3 hours. The carbon mass content was 0.3%, and a regenerated catalyst was obtained.

[0041] Using the same reforming oil, at 2.8MPa, 10h -1 , enter the deolefination reactor containing 8.0g of regenerated catalyst at 190℃, and after 212h of reaction, the outlet bromine index reaches more than 150mgBr / 100g.

[0042] Example 2

[0043] The reforming oil with a mass content of 0.3% non-aromatics, 0.3% toluene, 55.1% C8 aromatics, 37.2% C9 aromatics, 7.1% C10 aromatics and above, and an olefin content of 1940mgBr / 100g calculated by bromine index, is heated at 2.8MPa and 10h -1 , entering into a deolefination reactor containing 15.0 g of USY molecular sieve catalyst at 190°C, and reacting for 202 hours at an outlet bromine index of more than 150 mgBr / 100 g. After stopping, the catalyst was purged at 120°C for 20 hours to obtain a catalyst containing carbon deposits, wherein the mass content of the carbon deposits in terms of carbon was 25%.

[0044] The catalyst containing carbon deposits was first heated to 450°C at 1.5°C / min in an air atmosphere and then kept at this temperature for 4 hours, with the remaining carbon content being 10.5%. The catalyst was then subjected to a first ultrasonic treatment, wherein the first solution used was a solution containing potassium hydroxide and potassium chloride (the mass concentration of potassium chloride was 1%), the pH value of the first solution was 7.5, and the ultrasonic power density was 1.5 W / cm 2 The mixture was treated for 7 hours at a liquid-to-solid ratio of 9 and a temperature of 30°C. The mixture was filtered and washed, and then subjected to a second ultrasonic treatment. The second solution used was a sulfuric acid solution with a pH value of 6.0. The ultrasonic power density was 0.5 W / cm 2 The catalyst was treated at 120°C for 10 hours, with a liquid-to-solid mass ratio of 9.0 and a temperature of 70°C, filtered and washed; the second ultrasonic treatment was repeated once. The catalyst was then dried at 120°C for 10 hours, and then heated to 300°C at a rate of 2°C / min for 7 hours. The carbon mass content was 0.7%, and a regenerated catalyst was obtained.

[0045] Using the same reforming oil, at 2.8MPa, 10h -1 , enter the deolefination reactor at 190°C to take 8.0g of regenerated catalyst, and after 200h of reaction, the outlet bromine index reaches more than 150mgBr / 100g.

[0046] Example 3

[0047] The reforming oil with a mass content of 0.3% non-aromatics, 0.3% toluene, 95.1% C8 aromatics, 3.9% C9 aromatics, 0.2% C10 aromatics and above, and an olefin content of 160mgBr / 100g calculated by bromine index, is heated at 2.8MPa and 26h -1 , entering into a deolefination reactor containing 5.0 g of MCM-22 molecular sieve catalyst at 190°C, and reacting for 262 hours at an outlet bromine index of more than 20 mgBr / 100 g. After stopping, the catalyst was purged at 120°C for 20 hours to obtain a catalyst containing carbon deposits, wherein the mass content of the carbon deposits in terms of carbon was 13%.

[0048] The catalyst containing carbon deposits was first heated to 300°C at 2°C / min in an air atmosphere and then kept at this temperature for 6 hours, with the remaining carbon content being 3.0%. The first ultrasonic treatment was then performed, wherein the first solution used was a solution containing lithium hydroxide and lithium chloride (the mass concentration of lithium chloride was 1%), the pH value of the first solution was 9.0, and the ultrasonic power density was 0.2 W / cm 2 The mixture was treated for 6 hours at a liquid-to-solid ratio of 10 and a temperature of 100°C. The mixture was filtered and washed, and then subjected to a second ultrasonic treatment. The second concentration used was a hypochlorous acid solution with a pH value of 4.0. The ultrasonic power density was 0.5 W / cm 2 The catalyst was treated for 6 hours at a liquid-to-solid mass ratio of 5.0 and a temperature of 50°C, filtered and washed; then dried at 120°C for 10 hours, and then heated to 250°C at a rate of 1°C / min for 3 hours, with a carbon mass content of 0.2%, to obtain a regenerated catalyst.

[0049] Using the same reforming oil, at 2.8MPa, 26h -1 , enter the deolefination reactor at 190°C to take 3.0g of regenerated catalyst, and after 260h of reaction, the outlet bromine index reaches more than 20mgBr / 100g.

[0050] Example 4

[0051] The reforming oil with a mass content of 0.3% non-aromatics, 0.3% toluene, 55.1% C8 aromatics, 37.2% C9 aromatics, 7.1% C10 aromatics and above, and an olefin content of 1183mgBr / 100g based on the bromine index, is heated at 2.8MPa and 6h -1 , entering into a deolefination reactor containing 10.0 g of BETA molecular sieve catalyst at 180°C, and after 152 hours of reaction, the outlet bromine index reached more than 150 mgBr / 100 g. After stopping, the reactor was purged at 120°C for 20 hours to obtain a catalyst containing carbon deposits, wherein the mass content of the carbon deposits in terms of carbon was 13%.

[0052] The catalyst containing carbon deposits was first heated to 450°C at 1°C / min in an air atmosphere and then kept at this temperature for 3 hours, with the remaining carbon content being 5.0%. The catalyst was then subjected to a first ultrasonic treatment, wherein the first solution used was an ammonia solution containing ammonium chloride (with an ammonium chloride mass concentration of 2%), the pH value of the first solution was 9.0, and the ultrasonic power density was 8.0 W / cm 2 The mixture was treated for 2 h at a liquid-to-solid mass ratio of 5 and a temperature of 50 °C. The mixture was filtered and washed, and then mixed with an oxalic acid solution and subjected to a second ultrasonic treatment. The pH value of the oxalic acid solution used was 6.0. The ultrasonic power density was 3.0 W / cm 2The mixture was treated for 3 hours at a liquid-to-solid ratio of 4.0 and a temperature of 60°C, filtered and washed; then mixed with a hypochlorous acid solution and subjected to a second ultrasonic treatment. The pH value of the hypochlorous acid solution used was 5.0. The ultrasonic power density was 0.3 W / cm 2 The catalyst was treated at 30°C for 6 hours, with a liquid-to-solid mass ratio of 7.0, and then filtered and washed; then dried at 120°C for 10 hours, and then heated to 400°C at 2°C / min for 10 hours, and the carbon mass content was 0.3%, thereby obtaining a regenerated catalyst.

[0053] Using the same reforming oil, at 2.8MPa, 6h -1 , enter the deolefination reactor at 180°C to take 7.0g of regenerated catalyst, and after 163h of reaction, the outlet bromine index reaches more than 150mgBr / 100g.

[0054] Example 5

[0055] The reforming oil with a mass content of 0.2% non-aromatics, 0.2% toluene, 52.1% C8 aromatics, 44.2% C9 aromatics, 3.3% C10 aromatics and above, and an olefin content of 640mgBr / 100g calculated by bromine index, is heated at 1.0MPa, 6h -1 , entering into a deolefination reactor containing 15.0 g of SAPO-11 molecular sieve catalyst at 170°C. After 130 hours of reaction, the outlet bromine index reached more than 150 mgBr / 100 g. After stopping, the reactor was purged at 120°C for 20 hours to obtain a carbon deposit with a carbon content of 10.2%.

[0056] The catalyst containing carbon deposits was first heated to 420°C at 1.5°C / min in an air atmosphere and then kept at this temperature for 6 hours, with the remaining carbon content being 4.1%. The first ultrasonic treatment was then performed, wherein the first solution used was a mixed solution containing sodium hydroxide and sodium chloride (the mass concentration of sodium chloride was 1%), the pH value of the first solution was 8.5, and the ultrasonic power density was 4.0 W / cm 2 The mixture was treated for 10 h at a liquid-to-solid mass ratio of 6 and a temperature of 80 °C. The mixture was filtered and washed, and then subjected to a second ultrasonic treatment. The second solution used was a phosphoric acid solution with a pH value of 6.0. The ultrasonic power density was 0.5 W / cm 2 The catalyst was treated for 8 hours at a liquid-to-solid mass ratio of 6.0 and a temperature of 50°C, filtered and washed; the second ultrasonic treatment was repeated twice. The catalyst was then dried at 120°C for 10 hours, and then heated to 300°C at a rate of 2°C / min for 7 hours. The carbon mass content was 0.7%, and a regenerated catalyst was obtained.

[0057] Using the same reforming oil, at 1.0MPa, 6h -1, enter the deolefination reactor at 170°C to take 8.0g of regenerated catalyst, and after 145h of reaction, the outlet bromine index reaches more than 150mgBr / 100g.

[0058] Example 6

[0059] The reforming oil with a mass content of 0.5% non-aromatic hydrocarbons, 54.1% benzene, 45% toluene, 94.1% C8 aromatic hydrocarbons, 5.1% C9 aromatic hydrocarbons and above, and an olefin content of 180mgBr / 100g calculated by bromine index, is heated at 2.0MPa and 30h -1 , enter the deolefination reactor containing 5.0g Y molecular sieve catalyst at 180°C, and after 220h of reaction, the outlet bromine index reaches more than 15mgBr / 100g. After stopping, it is purged with nitrogen at 120°C for 20h, and the mass content of carbon deposit obtained is 10% in terms of carbon.

[0060] The catalyst containing carbon deposits was first heated to 350°C at 2°C / min in an air atmosphere and then kept at this temperature for 7 hours, with the remaining carbon content being 4.8%. The first ultrasonic treatment was then performed, wherein the first solution used was a solution containing sodium hydroxide and sodium nitrate (the mass concentration of sodium nitrate was 2%), the pH value of the first solution was 8, and the ultrasonic power density was 0.9 W / cm 2 The mixture was treated for 5 h at a liquid-to-solid mass ratio of 6 and a temperature of 50 °C. The mixture was filtered and washed, and then subjected to a second ultrasonic treatment. The second solution used was a sulfuric acid solution with a pH value of 5.0. The ultrasonic power density was 0.8 W / cm 2 The catalyst was treated for 6 hours at a liquid-to-solid mass ratio of 20.0 and a temperature of 90°C, filtered and washed; then dried at 120°C for 10 hours, and then heated to 300°C at a rate of 2°C / min for 3 hours. The carbon deposit had a carbon content of 0.2%, thereby obtaining a regenerated catalyst.

[0061] Using the same reforming oil, at 2.0MPa, 30h -1 , enter the deolefination reactor with 4.0g regenerated catalyst at 180℃, and after 235h of reaction, the outlet bromine index reaches more than 15mgBr / 100g.

[0062] Comparative Example 1

[0063] The reforming oil with a mass content of 0.3% non-aromatics, 0.3% toluene, 55.1% C8 aromatics, 37.2% C9 aromatics, 7.1% C10 aromatics and above, and an olefin content of 1210mgBr / 100g calculated by bromine index, is heated at 2.8MPa and 10h -1, entering a deolefination reactor containing 10.0 g of Y molecular sieve catalyst (same as in Example 1) at 190° C., and reacting for 202 hours at an outlet bromine index of more than 150 mgBr / 100 g. After stopping, the reactor was purged at 120° C. for 20 hours to obtain a carbon deposit having a carbon content of 15% by mass.

[0064] The catalyst containing carbon deposits was first heated to 540° C. at 2° C. / min in an air atmosphere and then subjected to constant temperature treatment for 3 hours, and the remaining carbon mass content was 0.2%, thereby obtaining a regenerated catalyst.

[0065] At 2.8MPa, 10h -1 , enter the deolefination reactor at 190°C to take 8.0g of regenerated catalyst, and after 152h of reaction, the outlet bromine index reaches more than 150mgBr / 100g.

[0066] Comparative Example 2

[0067] The reforming oil with a mass content of 0.3% non-aromatics, 0.3% toluene, 55.1% C8 aromatics, 37.2% C9 aromatics, 7.1% C10 aromatics and above, and an olefin content of 1210mgBr / 100g calculated by bromine index, is heated at 2.8MPa and 10h -1 , entering a deolefination reactor containing 10.0 g of Y molecular sieve catalyst (same as in Example 1) at 190° C., and reacting for 202 hours at an outlet bromine index of more than 150 mgBr / 100 g. After stopping, the reactor was purged at 120° C. for 20 hours to obtain a carbon deposit having a carbon content of 15% by mass.

[0068] The catalyst containing carbon deposits was first heated to 400°C at 2°C / min in an air atmosphere and then treated at a constant temperature for 5 hours, the remaining carbon content was 8.0%, then mixed with the first solution (same as Example 1) for non-ultrasonic treatment, the liquid-to-solid mass ratio was 6, the temperature was 60°C, filtered and washed, then mixed with the second solution (same as Example 1) for non-ultrasonic treatment, the liquid-to-solid mass ratio was 5.0, the temperature was 90°C, filtered and washed; then dried at 120°C for 10 hours, and then heated to 380°C at 2°C / min for 3 hours, the carbon content was 1.5%, and a regenerated catalyst was obtained.

[0069] Using the same reforming oil, at 2.8MPa, 10h -1 , enter the deolefination reactor at 190°C to take 8.0g of regenerated catalyst, and after 178h of reaction, the outlet bromine index reaches more than 150mgBr / 100g.

[0070] The embodiments of the present invention are only used to illustrate the detailed process flow of the present invention, but the present invention is not limited to the above detailed process flow, that is, the present invention can be implemented without relying on the steps described in the above embodiments. In summary, any improvements made by those skilled in the art to the present invention, including replacement of the raw materials and additives described in the present invention, selection of specific implementation methods, etc., all belong to the protection scope and disclosure scope of the present invention.

Claims

1. A method for regenerating an aromatics refining catalyst, wherein the aromatics refining catalyst is a molecular sieve catalyst, and the molecular sieve is one or more of a ten-membered ring or twelve-membered ring molecular sieve containing silicon-aluminum oxide or a molecular sieve containing silicon-phosphorus-aluminum oxide; the regeneration method comprises: (1) calcining the aromatics refining catalyst containing carbonaceous deposits to be regenerated in an oxygen-containing atmosphere at a temperature not greater than 450° C.; (2) subjecting the mixture of the catalyst treated in step (1) and the first solution to a first ultrasonic treatment, wherein the pH value of the first solution is 7.0 to 10.0; (3) subjecting the mixture of the catalyst treated in step (2) and the second solution to a second ultrasonic treatment, wherein the pH value of the second solution is 4.0 to 7.0 and is not 7.0; (4) calcining the catalyst treated in step (3) in an oxygen-containing atmosphere at a temperature 10°C lower than the calcination temperature in step (1) to obtain a regenerated catalyst; In step (2), the first solution is a solution containing Group IA elements and / or ammonium ions, and the first ultrasonic treatment conditions are as follows: the ultrasonic power density is 0.1-10 W / cm 2 , the treatment time is 0.1~100h, the liquid-to-solid mass ratio is 0.6~100, and the temperature is 30~100℃; in step (3), the second solution is an inorganic acid solution, and the acid is selected from one or more of sulfuric acid, hydrogen halide, nitric acid, phosphoric acid, and halogen acid; the second ultrasonic treatment conditions are as follows: the ultrasonic power density is 0.1~10W / cm 2 , processing time is 0.1~100h, liquid-solid mass ratio is 0.6~100, and temperature is 30~100℃.

2. The regeneration method according to claim 1, characterized in that: The ten-membered ring or twelve-membered ring molecular sieve containing silicon aluminum oxide type includes at least one of ZSM-5, MOR, BETA, Y molecular sieve, MCM-22, MCM-56, and ZSM-11, and the molecular sieve containing silicon phosphorus aluminum oxide includes at least one of SAPO-11 and SAPO-34.

3. The regeneration method according to claim 1, characterized in that: Based on the mass of the aromatics refining catalyst containing carbonaceous sediments to be regenerated, the mass content of carbon is above 0.1%.

4. The regeneration method according to claim 3, characterized in that: The mass content of carbon is above 2.0%.

5. The regeneration method according to claim 3, characterized in that: The mass content of carbon is above 3.0%.

6. The regeneration method according to claim 1, characterized in that: In step (1), the calcination temperature is 200-450° C., and the calcination time is 0.5-100 h; and / or, the calcination temperature in step (4) is 40° C. or more lower than the calcination temperature in step (1), and the calcination time is 0.5-100 h.

7. The regeneration method according to claim 1, characterized in that: After the treatment in step (1), the carbon deposit removal rate is more than 50%, and after the treatment in step (3), the total carbon deposit removal rate is more than 70%.

8. The regeneration method according to claim 1, characterized in that: After the treatment in step (1), the carbon deposit removal rate is more than 70%, and after the treatment in step (3), the total carbon deposit removal rate is more than 80%.

9. The regeneration method according to claim 1, characterized in that: In step (2), the pH value of the first solution is 7.0-9.0 and not 7.0, and the ultrasonic power density is 0.2-5 W / cm 2 , the treatment time is 0.5~20h, the liquid-to-solid mass ratio is 2~12, the temperature is 40~70°C; and / or the pH value of the second solution is 4.0~6.5, the ultrasonic power density is 0.2~5W / cm 2 The processing time is 0.5~40h, the liquid-to-solid mass ratio is 2~20, and the temperature is 40~70℃.

10. The regeneration method according to claim 1, characterized in that: The number of times of the first ultrasonic treatment in step (2) is 1 to 4 times; and / or the number of times of the second ultrasonic treatment in step (3) is 1 to 4 times.

11. The regenerated catalyst prepared by the regeneration method according to any one of claims 1 to 10.

12. Use of the regenerated catalyst according to claim 11 in the deolefination of aromatic hydrocarbons.