A regeneration method of a chemical hydrocracking catalyst, a regenerated catalyst obtained by the method and application thereof

Abstract

The present application relates to a kind of chemical hydrocracking catalyst regeneration method and the regenerated catalyst and its application obtained.The method includes the step of calcining the deactivated hydrocracking catalyst in oxygen-containing atmosphere, activating in acid solution, reducing in hydrogen atmosphere, restores the activity and nitrogen resistance of regenerated catalyst.This method can be used for the regeneration of chemical hydrocracking catalyst, solve the problem that activity and nitrogen resistance cannot be fully restored after calcination, and good technical effect is obtained.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of catalyst regeneration technology, and particularly relates to a regeneration method of a hydrocracking catalyst, a regenerated catalyst obtained by the method and application of the regenerated catalyst. BACKGROUND

[0002] Hydrocracking is one of the main processes for deep processing of heavy distillate oil, which refers to a process of making more than 10% of molecules in the feedstock oil smaller through hydrogenation reaction. Hydrocracking technology is one of the important means for secondary processing of crude oil and lightening of heavy oil. Due to its strong adaptability to feedstock, flexible operation and product scheme, and good product quality, it has become an important way to produce high-quality gasoline and diesel products. A large number of patents are related to traditional oil refining type hydrocracking catalysts, for example, Chinese patent CN1040611A discloses a hydrocracking catalyst and its application in a hydrocracking process, and the hydrocracking catalyst contains a Y zeolite type acidic matrix and a group VIII-VIB metal sulfide hydrogenation active component.

[0003] With the stagnation of diesel demand growth, catalytic diesel and ethylene tar are rich in heavy aromatics, and C 11 + Aromatics are mainly naphthalene series, indene series, acenaphthene, and anthracene, phenanthrene, etc. double-ring aromatics and three-ring aromatics, although their boiling points are in the diesel fraction, but due to the presence of a large number of condensed ring aromatics, etc., the economic efficiency of processing them into diesel is poor. On the basis of existing oil refining type hydrocracking catalysts and process technologies, technologies for converting catalytic diesel into high-octane gasoline blending components have been developed in existing research, for example, Chinese patents CN101724454A and CN102839018A report such methods, and the obtained heavy naphtha fraction has an aromatic content of 50-65%, which can be used as a high-octane gasoline blending component, and the catalyst used contains 20-75wt% of Y type molecular sieve. However, due to the wide pore of Y type molecular sieve, its space index is close to 20 (reference document Catalytic hydrocracking-mechanisms and versatility of the process, ChemCatChem 2012, 4, 292-306), and it does not have the shape-selective effect of strengthening the cracking of non-aromatics, C 10 The aromatic content of the fraction is low, and the non-aromatic content is high, which cannot meet the indicators of reformate, and there are obvious difficulties in entering the aromatics combination device as raw materials for producing benzene and p-xylene.

[0004] Chinese patent CN110180581A introduces a chemical type hydrocracking catalyst, which uses low space index zeolite with space index between 6-18 as solid acid component, and uses the complex of group VIII element and group VIB oxide as metal functional component, and can be used to convert catalytic diesel oil, ethylene tar and the like into light aromatic hydrocarbon and light hydrocarbon cracking material and the like aromatic hydrocarbon, olefin chemical raw material. The chemical type hydrocracking catalyst can maximize the conversion of these poor oil products into light aromatic hydrocarbon meeting the quality index requirements of aromatic hydrocarbon combination device, and the byproduct can be used as high-quality light hydrocarbon of olefin raw material, and provides raw material for chemical products such as aromatic hydrocarbon and olefin, and realizes the utilization of poor heavy aromatic hydrocarbon resources and the cost reduction and efficiency increase of aromatic hydrocarbon industry through refining integration.

[0005] When entering the end of industrial production operation, usually more than 10wt% of carbon deposition is deposited on the catalyst, the diffusion channel in the catalyst particle is blocked, and the zeolite acid center is covered with carbon deposition. Even through increasing the reaction temperature and the like, the reaction conversion rate, product selectivity and product quality index are greatly reduced, at which time the catalyst needs to be regenerated. Chinese patent CN106669710A discloses a regeneration method of catalytic diesel hydrocracking catalyst, which comprises the steps of calcining in an oxygen-containing atmosphere to a carbon removal rate of 40% to 80%, and then high-temperature treatment in an inert atmosphere, which better solves the problem of initial activity of the catalyst. However, this regeneration scheme is only suitable for metal sulfide / Y zeolite bifunctional hydrocracking catalyst, and is not suitable for regeneration of chemical type hydrocracking catalyst based on low space index zeolite. The regeneration of chemical type hydrocracking catalyst needs to solve the problem of large loss of catalyst activity in the catalyst regeneration process. It is urgent to develop a regeneration method for chemical type hydrocracking catalyst. SUMMARY

[0006] In view of the problem of no regeneration of chemical type hydrocracking catalyst in the prior art, the present application provides a regeneration method of chemical type hydrocracking catalyst and application thereof, in particular to a regeneration method of chemical type hydrocracking catalyst for converting catalytic diesel oil into high-quality light aromatic hydrocarbon and cracking material, which has the advantages of fully recovering the activity and nitrogen resistance of the regenerated catalyst.

[0007] One of the purposes of the present application is to provide a regeneration method of chemical type hydrocracking catalyst, which comprises calcining the deactivated chemical type hydrocracking catalyst in an oxygen-containing atmosphere, then activating in an acid solution, and finally reducing treatment in a hydrogen atmosphere to obtain a regenerated catalyst.

[0008] Specifically, in the above regeneration method,

[0009] The roasting can adopt the roasting equipment and process conditions commonly used in the art, and specifically can adopt industrial kiln such as converter, mesh belt kiln, tunnel kiln, vertical furnace, and the roasting conditions are preferably: the roasting temperature is 380-650℃, preferably 420-600℃; the roasting time is 1-8h, preferably 2-5h;

[0010] The acid in the acid solution comprises organic acid and inorganic acid; wherein the organic acid is selected from at least one of oxalic acid, citric acid, acetic acid, formic acid; the inorganic acid is selected from at least one of nitric acid, hydrochloric acid, sulfuric acid; the mass percentage concentration of the organic acid in the acid solution is 0.1-10%, preferably 0.5-8%; the mass percentage concentration of the inorganic acid is 0.1-8%, preferably 0.2-5%;

[0011] The acid solution is 0.5-2 times, preferably 0.6-1.2 times the weight of the chemical hydrocracking catalyst;

[0012] The activation temperature is 0-95℃, and the activation time is 1-24h;

[0013] The catalyst obtained after activation still needs drying treatment, and the drying treatment can be completed by using the drying equipment and drying conditions commonly used in the art;

[0014] The hydrogen pressure is 1-10MPa, preferably 2-9MPa;

[0015] The heating rate of the reduction treatment is 0.1-10℃ / min, preferably 1-5℃ / min;

[0016] The constant temperature temperature of the reduction treatment is 300-500℃, preferably 320-460℃;

[0017] The constant temperature time of the reduction treatment is 1-24h, preferably 2-18h.

[0018] The above regeneration method is suitable for the existing chemical hydrocracking catalyst in the prior art, and specifically, the chemical hydrocracking catalyst comprises zeolite and active component, preferably comprises: zeolite, Group VIII metal, Group VIB metal oxide, binder, and can further comprise other conventional components of catalyst in the art, such as diatomite.

[0019] wherein the zeolite has a space index less than 18; the zeolite is selected from at least one of a ten-membered ring zeolite, a twelve-membered ring zeolite, preferably at least one of mordenite, beta zeolite, MCM-22, ZSM-5; the Group VIII metal is selected from at least one of platinum, palladium, ruthenium, cobalt, nickel; the Group VIB metal oxide is selected from at least one of molybdenum oxide, tungsten oxide; the binder is selected from at least one of inorganic oxides, preferably at least one of alumina, silica-alumina composite, titania-alumina composite, and magnesia-alumina composite;

[0020] In the chemical type hydrocracking catalyst, the zeolite is 15-80 parts, the Group VIII metal is 0.01-7 parts, the Group VIB metal oxide is 2-24 parts, and the binder is 15-80 parts, by weight; preferably, the zeolite is 20-75 parts, the Group VIII metal is 0.05-6 parts, the Group VIB metal oxide is 5-20 parts, and the binder is 20-75 parts.

[0021] Specifically, the regeneration method of the chemical type hydrocracking catalyst is more suitable for the regeneration of a chemical type hydrocracking catalyst provided in Chinese Patent Application CN 110180581A. The content of Chinese Patent Application CN 110180581A is incorporated herein by reference in its entirety.

[0022] The hydrocracking catalyst described in Chinese Patent Application CN 110180581A uses a solid acid zeolite as an acid functional center of the catalyst and a hydrogenation active phase composed of a Group VIII metal and a Group VI metal oxide as a hydrogenation functional center of the catalyst. The catalyst can be applied to C 11 + Heavy aromatic hydrocarbon lightening reaction; can maximize the conversion of inferior oil products rich in condensed ring aromatic hydrocarbons into light aromatic hydrocarbons meeting the quality indicators of an aromatic hydrocarbon combination device, and produce high-quality light hydrocarbons that can be used as olefin raw materials, providing raw materials for chemical plants such as aromatic hydrocarbons and olefins, and realizing the utilization of inferior heavy aromatic hydrocarbon resources through refining integration.

[0023] The hydrocracking catalyst described in Chinese patent application CN 110180581A uses a low space index solid acid zeolite with a space index of 6-18, preferably beta zeolite, MCM-22 zeolite and / or mordenite. The low space index zeolite with a space index of 6-18 has a better shape selection effect and good aromatic hydrocarbon selectivity. However, how to maintain the nitrogen resistance of the low space index zeolite in the hydrocracking reaction is a difficult problem. The regeneration method of the present application is used to regenerate the hydrocracking catalyst described in Chinese patent application CN 110180581A, which has the characteristics of fully restoring the activity and nitrogen resistance of the regenerated catalyst, and meets the requirements of multi-cycle use of the catalyst.

[0024] The hydrocracking catalyst described above can be prepared by any method known in the art for preparing catalysts, without particular limitation. For example, the preparation of the catalyst described in the present application can include shaping the catalyst carrier containing the solid acid zeolite and loading the metal, and then calcining and activating to obtain the catalyst. Wherein the carrier shaping can be carried out by using the methods commonly used in the art such as extrusion, rolling or oil column shaping, etc. together with the binder, etc.; the metal loading can be carried out by the methods commonly used in the art such as co-precipitation, co-gelation, kneading, ion exchange or impregnation, etc.

[0025] Specifically, it can include the following steps: after mixing the solid acid zeolite with the binder, kneading, extruding, drying at 60-150℃, and then calcining at 500-600℃ in air atmosphere for 3-6 hours, the desired catalyst carrier is obtained. A metal aqueous solution is prepared by using Group VIII metal compound and Group VIB metal compound, and the catalyst carrier is impregnated by the equal volume impregnation method, dried at 60-150℃, and then calcined at 450-580℃ in air atmosphere for 1-6 hours to obtain the catalyst.

[0026] The second object of the present application is to provide a hydrocracking regenerated catalyst prepared by the above-mentioned regeneration method. The carbon deposition amount of the regenerated catalyst is less than 1wt%, and the recovery rate of strong B acid centers is greater than 90%.

[0027] The third object of the present application is to provide a regeneration method of the above-mentioned hydrocracking catalyst or the application of the above-mentioned regenerated catalyst in hydrocracking reaction. Among them, the C 11 and the weight percentage of aromatic hydrocarbons above is 60-100%, and the nitrogen content is less than 20ppm.

[0028] The present application is a regeneration method of hydrocracking catalyst, especially for the regeneration of hydrocracking catalyst with complex phase of Group VIII metal-Group VIB metal oxide as metal component (hydrogenation active phase) and zeolite with space index lower than 18 as acid center. The coke content of the regenerated catalyst is lower than 1wt%, and the recovery rate of strong B acid center is greater than 90%. The regenerated catalyst is used to treat poor raw materials in a hydrocracking device, wherein C 11 and the above aromatic hydrocarbon weight percentage is 60-100%, the nitrogen content is less than 20ppm, and the recovery rate of strong B acid center of the regenerated catalyst is greater than 90%. Unlike the regeneration method of traditional hydrocracking catalyst with Group VIII-VIB metal sulfide and USY zeolite as hydrogenation function and solid acid function, the present application is particularly suitable for recovering the activity of the regenerated hydrocracking catalyst, and the partial acid center of the catalyst is recovered under the action of complex acid, the homogenization effect of the hydrogenation active center is recovered due to the dissolution of the oxide, the coke content is further reduced, and good technical effects are achieved. DETAILED DESCRIPTION

[0029] The present application will be further described and explained with specific embodiments. However, it should be pointed out that the protection scope of the present application is not limited by the embodiments, but is determined by the claims. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, and these simple modifications all belong to the protection scope of the present application.

[0030] In addition, it should be pointed out that the various specific technical features described in the following embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present application will not further describe various possible combinations.

[0031] In addition, various different embodiments of the present application can also be combined in any manner without deviating from the concept of the present application, and the technical solutions formed thereby belong to the original disclosure of the present specification and fall within the protection scope of the present application, and should not be regarded as new content that has not been disclosed or anticipated in the present specification, unless the combination is deemed to be obviously unreasonable by those skilled in the art.

[0032] In the context of the present specification, except for the explicitly described content, any unmentioned matters or items directly apply to those known in the art without any change.

[0033] All publications, patent applications, patents and other references mentioned in the present specification are incorporated by reference. Unless otherwise defined, all technical and scientific terms used in the present specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in the present specification prevail.

[0034] When the specification derives a material, substance, method, step, device or component etc. with the word head "known to those skilled in the art", "prior art" or similar, the object derived by the word head covers those which are conventionally used in the art at the time of the present application, but also those which are not yet conventionally used, but will become recognized as suitable for similar purposes in the art.

[0035] All percentages, parts, ratios, etc. mentioned in the present specification are based on weight, unless otherwise indicated; temperatures are given in degrees Celsius; pressures in bar; and air velocities mentioned are liquid hourly space velocities LHSV.

[0036] The endpoints of the ranges and any values claimed herein are presented exclusively by their numeric values. Ranges can be expressed herein with endpoints by using the language "about", "substantially", or "approximately". Unless otherwise indicated, the exact dimensions need not to be achieved with the preferred embodiments. It is contemplated that any method, material or component, configuration or combination thereof described herein can be substituted for any other method, material or component, configuration or combination thereof described herein. Any method, material or component, configuration or combination thereof described herein can be excluded from any embodiment.

[0037] Test methods and standards referred to in the detailed description of the application:

[0038] 1. In the present application, the composition of the catalyst is analyzed by ICP (inductively coupled plasma) and XRF (X-ray fluorescence) methods. The ratio of the VIB group metal oxides is determined by XPS (X-ray photoelectron spectroscopy) method. The ICP test conditions are: Varian 700-ES series XPS instrument. The XRF test conditions are: Rigaku ZSX 100e type XRF instrument. The XPS test conditions: Perkin Elmer PHI 5000C ESCA type X-ray photoelectron spectrometer, using Mg K excitation light source, operating voltage l0kV, current 40mA, vacuum degree 4.0x10 -8 Pa.

[0039] 2. The Spaciousness Index (SI) is an index representing the degree of opening of the pores of the zeolite, ranging from 0 to 21. After loading 0.1-0.5wt% of platinum or palladium noble metal on a specific zeolite, it is used for the hydrocracking reaction of butylcyclohexane, and the molar ratio of isobutane and n-butane in the product is analyzed, which is the pore space index of this twelve-membered ring zeolite. The spaciousness index can represent the opening degree of the pores of the solid acid zeolite.

[0040] 3. The amount of strong Brønsted acid in chemical-grade hydrocracking catalysts was characterized using a pyridine-infrared (Py-IR) method, employing a Thermo Nicolet NEXUS Fourier transform infrared spectrometer. The 1450 cm⁻¹ value was used for characterization. -1 The characteristic peak is attributed to the L-acid center, at 1540 cm⁻¹. -1 Characteristic peaks were assigned to Brønsted acid centers. The amount of pyridine adsorbed after desorption at 250℃ was taken as the total acid amount, and the amount of pyridine adsorbed after desorption at 400℃ was taken as the amount of strong Brønsted acid.

[0041] 4. The amount of catalyst coke was determined using an ELEMENFARVARIOEL elemental analyzer. 5 mg of deactivated catalyst powder was placed in the sample chamber and burned at 1100℃ for 9-12 minutes under a fixed Ar / O2 (200 / 90 mL / min) gas flow. The generated gas was then analyzed by chromatography, and the amount of catalyst coke before and after regeneration was calculated.

[0042] The calculation basis for the main result data involved in the specific implementation of this invention is as follows:

[0043] 1. C 11 + The formula for calculating the conversion rate of aromatics is:

[0044]

[0045] C after 500 hours online 11 + The conversion rate of aromatics serves as a criterion for judging the effectiveness of regenerator activity recovery.

[0046] The raw materials involved in the specific embodiments of this invention are as follows:

[0047] 1. To illustrate the effects of the present invention, the composition of the feedstock oil is shown in Table 1, which is hydrorefined catalytic diesel.

[0048] 2. The raw materials, including but not limited to catalysts, involved in the embodiments and comparative examples of this invention are all commercially available.

[0049] Table 1. Composition of Raw Material Oil 1

[0050] Feed oil 1 Density (4°C) 0.92 Sulfur (ppm) 69 Nitrogen (ppm) 11 Non-aromatic hydrocarbons (wt%) 17.60 Monocyclic aromatic hydrocarbons (wt%) 70.27 Condensed ring aromatic hydrocarbons (wt%) 12.13 C 11 + A content (wt%) 82.24 Initial boiling point 155 5％ 178 10％ 186 30％ 220 50％ 239 70％ 261 90％ 283 Final boiling point 321

[0051] Comparative Example 1

[0052] Chemical hydrocracking catalyst C1 composition: 3.5 parts Co-6.3 parts WO2-8.9 parts WO3 / 52 parts β zeolite-29.3 parts Al2O3, β zeolite space index 17.1. Pyridine infrared method characterization, strong B acid center amount 4.08 mmol / g. Using raw material 1, continuously injecting into the fixed bed reactor, reaction conditions: temperature 370°C, hydrogen partial pressure 6.0 MPa, liquid space velocity 1.5 hours -1 , hydrogen / hydrocarbon volume ratio 2000. After online 500 hours C 11 + A conversion rate is 78.42wt%.

[0053] After completing a cycle of online operation, unloading the deactivated catalyst, carrying out carbon burning regeneration in an industrial converter. Into the regeneration furnace, oxygen / nitrogen mixed gas with oxygen content 11% is passed, control gas / catalyst ratio 4000; constant temperature section control temperature is 520°C, constant temperature time 3 hours, complete calcination process, obtain regenerated catalyst C1-R1, catalyst coke amount 0.86wt%. Pyridine infrared method characterization, strong B acid center amount 3.14 mmol / g, strong B acid center retention rate after regeneration 76.96%.

[0054] C1-R1 catalyst is loaded into the fixed bed reactor, the reactor and the circulating system are replaced with nitrogen to less than 0.1% oxygen content, then replaced with hydrogen with purity 92% and pressurized to 7.0 MPa. According to the temperature rising program of 0.1°C / min, slowly increase the inlet temperature to 420°C, then keep this temperature for 15 hours to complete the reduction process.

[0055] Using raw material 1, continuously injecting into the fixed bed reactor, reaction conditions: temperature 370°C, hydrogen partial pressure 6.0 MPa, liquid space velocity 1.5 hours -1 , hydrogen / hydrocarbon volume ratio 2000. After online 500 hours C 11 + A conversion rate is 48.65wt%, activity recovery rate is poor.

[0056] Comparative example 2

[0057] C1-R1 catalyst is treated with organic acid solution. In the enamel kettle, 1 cubic meter oxalic acid solution is added, oxalic acid concentration is 1.5wt%, heated to 50°C. Add 1.4 tons of C1-R1 catalyst, the oxalic acid solution is completely absorbed by the catalyst, after standing for 4 hours, dry at 110°C for 18h, cool to room temperature to complete the activation treatment, obtain regenerated catalyst C1-R2', catalyst coke amount is further reduced to 0.64wt%. Pyridine infrared method characterization, strong B acid center amount 3.05 mmol / g, strong B acid center retention rate after two-step regeneration 74.75%.

[0058] The reactor and recycle system were purged with nitrogen to an oxygen content of less than 0.1%, then with hydrogen of 92% purity to a pressure of 7.0 MPa. The inlet temperature was slowly increased to 420°C at a ramp rate of 0.1°C / min, then held at this temperature for 15 hours to complete the reduction procedure.

[0059] The feedstock 1 was continuously injected into the fixed bed reactor under the following conditions: temperature 370°C, hydrogen partial pressure 6.0 MPa, liquid hourly space velocity 1.5 hour"1, hydrogen to hydrocarbon volume ratio 2000. The conversion of C -1 11 + The conversion of C A was 46.21 wt%, and the activity recovery was poor.

[0060] [Comparative Example 3]

[0061] The C1-R1 catalyst was treated with an inorganic acid solution. In a porcelain kettle, 1 cubic meter of sulfuric acid solution was added, with a sulfuric acid concentration of 2.0 wt%, and the temperature was raised to 35°C. 1.4 tons of C1-R1 catalyst was added, and the sulfuric acid solution was completely absorbed by the catalyst. After standing for 4 hours, the catalyst was dried at 110°C for 18 hours, and then cooled to room temperature to complete the activation treatment, to obtain the regenerated catalyst C1-R2". The carbon deposition on the catalyst was further reduced to 0.69 wt%. The pyridine infrared method was used for characterization, and the amount of strong B acid sites was 3.52 mmol / g. After two steps of regeneration, the retention rate of strong B acid sites was 86.27%.

[0062] The reactor and recycle system were purged with nitrogen to an oxygen content of less than 0.1%, then with hydrogen of 92% purity to a pressure of 7.0 MPa. The inlet temperature was slowly increased to 420°C at a ramp rate of 0.1°C / min, then held at this temperature for 15 hours to complete the reduction procedure.

[0063] The feedstock 1 was continuously injected into the fixed bed reactor under the following conditions: temperature 370°C, hydrogen partial pressure 6.0 MPa, liquid hourly space velocity 1.5 hour"1, hydrogen to hydrocarbon volume ratio 2000. The conversion of C -1 11 + The conversion of C A was 58.63 wt%, and the activity recovery was poor.

[0064] [Example 1]

[0065] The catalyst composition and calcination steps were the same as in Comparative Example 1.

[0066] ​​The C1-R1 catalyst was further activated by a complex acid solution. In an enamel kettle, 1 cubic meter of complex acid solution was added, in which the concentration of nitric acid was 2 wt%, and the concentration of oxalic acid was 0.5 wt%. The temperature was raised to 50°C. 1.4 tons of C1-R1 catalyst was added, and the complex acid solution was completely absorbed by the catalyst. After standing for 4 hours, the catalyst was dried at 110°C for 18 hours, and the temperature was lowered to room temperature to complete the activation process, thereby obtaining regenerated catalyst C1-R2, and the coke content of the catalyst was further reduced to 0.32 wt%. Pyridine infrared characterization showed that the amount of strong B acid center was 3.77 mmol / g, and the retention rate of strong B acid center after two steps of regeneration was 92.40%.

[0067] The C1-R2 catalyst was loaded into a fixed bed reactor, the reactor and the circulation system were replaced with nitrogen to an oxygen content of less than 0.1%, and then replaced with hydrogen with a purity of 92% and pressurized to 7.0 MPa. The inlet temperature was slowly increased to 420°C at a temperature rising rate of 0.1°C / min, and then maintained at this temperature for 15 hours to complete the reduction process.

[0068] The raw material 1 was continuously injected into the fixed bed reactor under the following reaction conditions: temperature 370°C, hydrogen partial pressure 7.0 MPa, liquid space velocity 1.5 hours -1 , and hydrogen to hydrocarbon volume ratio 2000. After 500 hours of online operation, the conversion of C 11 + The conversion of A was 77.13 wt%, indicating that the activity of the regenerated catalyst was well recovered. By the steps of calcining the deactivated chemical type hydrocracking catalyst in an oxygen-containing atmosphere, activating it in a complex acid solution, and reducing it in a hydrogen atmosphere, the activity recovery effect of the chemical type hydrocracking catalyst was good.

[0069] Example 2

[0070] The chemical type hydrocracking catalyst C2 was composed of 0.10 parts of Pt-4.25 parts of MoO2-6.87 parts of MoO3 / 34.10 parts of mordenite-20 parts of ZSM-5-34.68 parts of Al2O3, and the space index of the mordenite was 7.3, and the space index of the ZSM-5 zeolite was 1.3. Pyridine infrared characterization showed that the amount of strong B acid center was 6.57 mmol / g. The C2 catalyst was loaded into a fixed bed reactor, the reactor and the circulation system were replaced with nitrogen to an oxygen content of less than 0.1%, and then replaced with hydrogen with a purity of 98% and pressurized to 8.0 MPa. The inlet temperature was slowly increased to 450°C at a temperature rising rate of 5°C / min, and then maintained at this temperature for 4 hours to complete the reduction process. The raw material 1 was continuously injected into the fixed bed reactor under the following reaction conditions: temperature 350°C, hydrogen partial pressure 8.0 MPa, liquid space velocity 1.0 hours -1 , and hydrogen to hydrocarbon volume ratio 2500. After 500 hours of online operation, the conversion of C 11 +A conversion is 81.32wt%.

[0071] After completing one cycle of on-line operation, the deactivated catalyst was unloaded and subjected to coke burning regeneration in an industrial mesh belt kiln. Air with 21% oxygen content was introduced into the mesh belt kiln, and the gas / catalyst ratio was controlled at 1000; the temperature in the constant temperature section was controlled at 530°C, and the constant temperature time was 2.5 hours, thus completing the calcination process, and obtaining regenerated catalyst C2-R1, with a coke content of 0.93wt%.

[0072] The C2-R1 catalyst was subjected to activation treatment by contacting with a composite acid solution. In a porcelain kettle, 1 cubic meter of composite acid solution was added, in which the concentration of nitric acid was 0.2wt%, the concentration of sulfuric acid was 2wt%, and the concentration of citric acid was 5wt%, and the temperature was raised to 70°C. 1.4 tons of C2-R1 catalyst was added, and the composite acid solution was completely absorbed by the catalyst. After standing for 4 hours, the catalyst was dried at 90°C for 12 hours, and the temperature was lowered to room temperature to complete the activation treatment, thus obtaining regenerated catalyst C2-R2, with a coke content of 0.75wt%. Pyridine infrared characterization showed that after two-step treatment, the amount of strong B acid center was 5.96mmol / g, and the retention rate of strong B acid center after regeneration was 90.72%.

[0073] The C2-R2 catalyst was loaded into a fixed bed reactor, and the reactor and the circulation system were replaced with nitrogen to an oxygen content of less than 0.1%, and then replaced with hydrogen with a purity of 98% and pressurized to 8.0MPa. The inlet temperature was slowly increased to 450°C at a temperature rising rate of 5°C / min, and then maintained at this temperature for 4 hours to complete the reduction process. Raw material 1 was continuously injected into the fixed bed reactor, and the reaction conditions were as follows: temperature 350°C, hydrogen partial pressure 8.0MPa, liquid space velocity 1.0hour -1 , hydrogen / hydrocarbon volume ratio 2500. After 500 hours of on-line operation, the C 11 + A conversion of 81.32wt% indicates that the activity of the regenerated catalyst is well recovered.

[0074]

Example 3

[0075] Chemical hydrocracking catalyst C3 composition: 1.5 parts Ni - 5.3 parts MoO2 - 2.5 parts MoO3 / 41 parts MCM-22 zeolite - 19.5 parts beta zeolite - 30.2 parts Al2O3, wherein the MCM-22 zeolite has a space index of 8.6 and the beta zeolite has a space index of 17.1. The pyridine infrared method characterization shows that the amount of strong B acid centers is 2.84 mmol / g. The C3 catalyst is loaded into a fixed bed reactor, the reactor and circulation system are replaced with nitrogen to an oxygen content of less than 0.1%, then replaced with hydrogen with a purity of 98% PSA hydrogen and pressurized to 7.0 MPa. The inlet temperature is slowly increased to 460°C according to a temperature increase program of 0.2°C / min, then maintained at this temperature for 12 hours to complete the reduction program. Raw material 1 is continuously injected into the fixed bed reactor, and the reaction conditions are: temperature 395°C, hydrogen partial pressure 8.0 MPa, liquid space velocity 1.0 hour -1 11 + A conversion rate of 90.75 wt%.

[0076] After completing one cycle of on-line operation, the deactivated catalyst is unloaded and subjected to carbon burning regeneration in an industrial mesh belt kiln. Air with an oxygen content of 21% is introduced into the mesh belt kiln, and the gas / catalyst ratio is controlled at 1200; the temperature in the constant temperature section is controlled at 510°C, and the constant temperature time is 4h, to complete the calcination process, obtaining regenerated catalyst C3-R1, and the carbon deposition amount of the catalyst is 0.95 wt%.

[0077] The C3-R1 catalyst is subjected to activation treatment by contacting with a composite acid solution. In the enamel kettle, 1 cubic meter of composite acid solution is added, wherein the concentration of sulfuric acid is 1.5 wt% and the concentration of oxalic acid is 3 wt%, and the temperature is raised to 80°C. 1.4 tons of C3-R1 catalyst is added, and the composite acid solution is completely absorbed by the catalyst. After standing for 4 hours, drying at 100°C for 12h, and cooling to room temperature, the activation treatment is completed, obtaining regenerated catalyst C3-R2, and the carbon deposition amount of the catalyst is further reduced to 0.84 wt%. Pyridine infrared method characterization shows that the amount of strong B acid centers after two steps of regeneration is 2.67 mmol / g, and the retention rate of strong B acid centers after regeneration is 94.01%.

[0078] The C3-R2 catalyst is loaded into a fixed bed reactor, the reactor and circulation system are replaced with nitrogen to an oxygen content of less than 0.1%, then replaced with hydrogen with a purity of 98% PSA hydrogen and pressurized to 7.0 MPa. The inlet temperature is slowly increased to 460°C according to a temperature increase program of 0.2°C / min, then maintained at this temperature for 12 hours to complete the reduction program.

[0079] Raw material 1 is continuously injected into the fixed bed reactor, and the reaction conditions are: temperature 395°C, hydrogen partial pressure 8.0 MPa, liquid space velocity 1.0 hour -1 ​, hydrogen hydrocarbon volume ratio 2500. After 500 hours on stream, C 11 + A conversion of 87.43 wt% with good activity recovery.

Claims

1. A method for regenerating a chemical-type hydrocracking catalyst, comprising calcining a deactivated chemical-type hydrocracking catalyst in an oxygen-containing atmosphere, activating it in an acid solution, and finally reducing it in a hydrogen atmosphere to obtain a regenerated catalyst; wherein the calcination temperature is 380~650℃, and the calcination time is 1~8h; the activation temperature is 0~95℃, and the activation time is 1~24h; wherein the acid in the acid solution comprises an organic acid and an inorganic acid, wherein the organic acid is selected from at least one of oxalic acid, citric acid, acetic acid, and formic acid, and the inorganic acid is selected from... The catalyst comprises at least one of nitric acid, hydrochloric acid, and sulfuric acid; wherein the organic acid has a mass percentage concentration of 0.1-10% and the inorganic acid has a mass percentage concentration of 0.1-8%; the acid solution is 0.5-2 times the weight of the chemical-type hydrocracking catalyst; the hydrogen gas pressure is 1-10 MPa; the heating rate of the reduction treatment is 0.1-10 °C / min; the isothermal temperature of the reduction treatment is 300-500 °C; and the isothermal time of the reduction treatment is 1-24 h; the chemical-type hydrocracking catalyst comprises: The mixture comprises zeolite, group VIII metal, group VIB metal oxide, and a binder, wherein the group VIII metal is selected from at least one of platinum, palladium, ruthenium, cobalt, and nickel, and the group VIB metal oxide is selected from at least one of molybdenum oxide and tungsten oxide.

2. The regeneration method according to claim 1, characterized in that, The calcination temperature is 420~600℃; and / or, The roasting time is 2-5 hours.

3. The regeneration method according to claim 1, characterized in that, The catalyst obtained after activation still needs to be dried.

4. The regeneration method according to claim 1, characterized in that, The acid solution is 0.6 to 1.2 times the weight of the chemical-type hydrocracking catalyst.

5. The regeneration method according to claim 1, characterized in that, In the acid solution, the organic acid has a mass percentage concentration of 0.5% to 8%; and / or, In the acid solution, the mass percentage concentration of the inorganic acid is 0.2-5%.

6. The regeneration method according to claim 1, characterized in that, The pressure of the hydrogen gas is 2~9 MPa; and / or, The heating rate of the reduction treatment is 1~5℃ / min; and / or, The isothermal temperature for the reduction treatment is 320~460℃; and / or, The isothermal treatment time is 2 to 18 hours.

7. The regeneration method according to claim 1, characterized in that, The zeolite has a space index of less than 18; and / or, The zeolite is selected from at least one of decacyclic zeolites and dodecylcyclic zeolites; and / or, The adhesive is selected from inorganic oxides.

8. The regeneration method according to claim 7, characterized in that, The zeolite is selected from at least one of mordenite, β-zeolite, MCM-22, and ZSM-5; and / or, The binder is at least one of the group consisting of alumina, silicon oxide-alumina composite, titanium oxide-alumina composite, and magnesium oxide-alumina composite.

9. The regeneration method according to claim 1, characterized in that, By weight, the zeolite in the chemical-type hydrocracking catalyst is 15-80 parts, the group VIII metal is 0.01-7 parts, the group VIB metal oxide is 2-24 parts, and the binder is 15-80 parts.

10. The regeneration method according to claim 9, characterized in that, By weight, the zeolite in the chemical-type hydrocracking catalyst is 20-75 parts, the group VIII metal is 0.05-6 parts, the group VIB metal oxide is 5-20 parts, and the binder is 20-75 parts.

11. A hydrocracking regeneration catalyst, prepared by the regeneration method according to any one of claims 1 to 10.

12. The regenerated catalyst according to claim 11, characterized in that, The amount of coke deposited in the regenerated catalyst is less than 1 wt%, and the recovery rate of strong Brønsted acid centers is greater than 90%.

13. A method for regenerating a hydrocracking catalyst according to any one of claims 1 to 10, or the application of the regenerated catalyst according to claim 11 or 12 in a hydrocracking reaction.

14. The application according to claim 13, characterized in that, The C in the hydrocracking feedstock 11 The aromatic hydrocarbons and above account for 60-100% by weight, and the nitrogen content is less than 20 ppm.

Images