Process for preparing a hydrocracking catalyst for the production of high-aromatics potential naphtha

Abstract

The application discloses a preparation method of a hydrocracking catalyst for producing high-aromatic potential naphtha, and the preparation method comprises the following steps: adding a mixed molecular sieve of Y / SAPO-34 / ZSM-5 into a bottom liquid, adding an aluminum sulfate solution and ammonia water to generate a precursor in parallel flow while stirring, aging, adding a water glass solution, performing second aging, adding a composite solvent drop by drop, performing third aging under stirring, and performing crystallization, washing, filtering, drying and calcining to obtain a modified molecular sieve oxide material; dissolving a tungsten precursor and a nickel precursor in water and adding a complexing agent; mixing the above solution, uniformly stirring, and then standing and drying to obtain a metal composite modified molecular sieve oxide; uniformly mixing alumina, the metal composite modified molecular sieve oxide, concentrated nitric acid and a sesbania powder, extruding into a strip, drying and calcining to obtain the hydrocracking catalyst. The catalyst prepared by the method realizes the production of high-aromatic potential naphtha by the hydrocracking catalyst.

Description

Technical Field

[0001] This invention belongs to the field of catalytic materials, specifically relating to a method for preparing a catalyst for hydrocracking to produce high-aromatic naphtha. Background Technology

[0002] With the annual increase in oil imports, processed crude oil is becoming increasingly heavy and of lower quality. Besides high sulfur and nitrogen content, crude oil also contains large amounts of aromatics, especially polycyclic aromatic hydrocarbons (PAHs). The presence of PAHs not only affects the quality of petroleum products but also poses serious threats to the ecological environment and human health. As environmental protection requirements become increasingly stringent, the quality requirements for clean fuels are also becoming more demanding. Oil quality standards are constantly rising, and how to take measures to maximize the conversion of heavy oil into high-value-added chemical feedstocks has become a hot research topic in the petrochemical field.

[0003] Hydrocracking is a crucial method for converting heavy oil into lighter products, offering numerous advantages such as strong feedstock adaptability, flexible processing options, high liquid product yields, and good product quality. It has become a core process for modern oil refining enterprises. The core of hydrocracking technology is the hydrocracking catalyst, composed of metallic components and acidic centers. Suitable catalyst pore structure and acid properties play a decisive role in regulating distillate oil yield and product distribution. During the hydrocracking reaction, heavy distillate oils are hydrogenated to saturation and undergo ring-opening cracking, effectively converting them into light distillate oils. To meet the ever-increasing global demand for light distillate oils, the development of novel, high-yield light oil hydrocracking catalysts has become the core and key to this technology. Current research indicates that the catalyst's structure and acid properties determine the hydrocracking performance.

[0004] CN201610288622.8 discloses a catalyst for producing reforming feedstock by hydrocracking and the production of heavy naphtha. It adopts a single-stage series one-pass process, in which wax oil feedstock passes through a pre-refining reactor and a hydrocracking reactor to produce heavy naphtha. Due to the simultaneous reaction of cyclic hydrocarbons and chain hydrocarbons in the wax oil feedstock, the yield and quality of heavy naphtha are relatively poor.

[0005] CN02129038.5 discloses a method for producing middle distillate oil products by hydrocracking. The refining feedstock enters the first stage hydrocracking reaction zone for conversion in a hydrogen-bearing state. The unconverted oil is recycled back to the second stage reaction zone for further conversion to produce jet fuel and diesel middle distillate products. However, this method cannot distinguish between different types of hydrocarbon components, resulting in poor quality diesel products.

[0006] CN113019426A discloses a hydrocracking catalyst support, a hydrocracking catalyst, and its preparation method. The support comprises a Y / Al-SBA-15 composite molecular sieve and alumina. The Y / Al-SBA-15 composite molecular sieve has a medium-strong acid content of 0.6–1.2 mL / g and a Brønsted acid to Lewis acid ratio of less than 1.2. The preparation method of the Y / Al-SBA-15 composite molecular sieve used in this support includes: using amorphous silica-alumina dry gel as raw material, and employing P123 triblock copolymer as a template agent for a first crystallization to synthesize Al-SBA-15 molecular sieve, followed by the addition of ultrastable Y molecular sieve slurry, and a second crystallization to obtain the Y / Al-SBA-15 composite molecular sieve. The drawback of this technology, or its deficiency compared to the present invention, is that the hydrocracking catalyst of this technology, when used in the hydrocracking reaction, only yields 35–40 wt% heavy naphtha and approximately 60 wt% aromatics.

[0007] CN111268689A discloses a method for preparing mesoporous molecular sieves without ammonia, characterized by the following steps: contacting molecular sieve raw materials with a dealuminizing agent in water for a chemical dealuminizing and pore-forming treatment without ammonia exchange, to obtain a secondary mesoporous molecular sieve product; the molecular sieve raw materials refer to natural or artificially synthesized molecular sieve raw materials with silicon-aluminum components or phosphorus-aluminum components; further, the molecular sieve raw materials are Y-type molecular sieves with a FAU topology; even further, it also includes molecular sieves with LTA, FAU, SOD, ANA, CAN, OFF, ERI, LEV, GME, CHA, LTL, MAZ, EAB, MOR, DAC, FER, EPI, BIK, BRE, MFI, MWW, or *BEA topologies. The drawback of this technology, or the deficiency relative to this invention, is that the process is relatively complex, and many factors influence the preparation process; otherwise, it is impossible to obtain Y-type molecular sieves with a FAU topology.

[0008] CN115583840A discloses a preparation process for porous silicon nitride ceramic materials, relating to the field of porous ceramic technology. The porous silicon nitride ceramic material comprises 45-65 parts silicon nitride, 1-5 parts sintering aid, and 15-35 parts aerogel powder. The aerogel powder is a graphene oxide / carboxymethyl cellulose aerogel, and the sintering aid is a rare earth oxide. The preparation process includes: preparation of graphene oxide aerogel, modification of the aerogel, preparation of ceramic slurry, drying and shaping of the ceramic slurry and debinding, and sintering of the porous ceramic. A combination of gel casting and pore-forming agent is used, adding graphene oxide / carboxymethyl cellulose aerogel powder to the silicon nitride ceramic slurry to create pores in the silicon nitride ceramic material without generating harmful gases. This solves the problems of low porosity, uneven pore distribution, environmental pollution, and complex preparation processes in existing porous silicon nitride ceramic material preparation methods. The drawback of this technology, or its deficiency relative to this invention, is that it results in a low yield of heavy naphtha in hydrocracking.

[0009] CN114367307A proposes a method for preparing a core-shell structured M@SSZ-13@NanoBeta. Specifically, a noble metal is in situ encapsulated within a core layer of SSZ-13 zeolite to form the core layer M@SSZ-13. A portion of this core layer sample is placed in a Beta synthesis gel, and after crystallization, a core-shell M@SSZ-13@NanoBeta is formed. The growth of the shell layer NanoBeta zeolite modifies the pores of the SSZ-13 zeolite, limiting the contact between sulfides and the noble metal, thus improving the catalyst's sulfur resistance. In the hydrogen spillover effect, the active hydrogen component can hydrogenate polycyclic aromatic hydrocarbons adsorbed at acidic sites in the shell layer. Subsequently, the hydrogenation products are further cracked on the NanoBeta zeolite, achieving selective hydrocracking of polycyclic aromatic hydrocarbons. The drawback of this technology, or its disadvantage compared to this invention, is the poor adaptability of the noble metal catalyst raw material and the high cost of the catalyst.

[0010] CN113694962A discloses a catalyst and its preparation method for isomerization dewaxing of hydrocracking tail oil to base oil, belonging to the field of catalytic materials. The method involves first ball milling two different types of molecular sieves, then adding oxides or metal salts containing Group VIII B metal elements and ball milling again, and finally kneading, extruding, drying, and calcining to produce the isomerization dewaxing catalyst. This invention uses ball milling to achieve thorough mixing of the molecular sieves, reduce agglomeration between them, and increase their surface area. Further ball milling allows the metal elements to chemically associate with the molecular sieves, thereby increasing the synergistic effect between the acid and metal in the catalyst and ensuring its hydrogenation / dehydrogenation activity. The drawback of this technology, or its relative deficiency compared to this invention, is that this method is used for isomerization dewaxing of tail oil to base oil and does not address the production of high-aromatic naphtha. Summary of the Invention

[0011] The purpose of this invention is to provide a method for preparing a hydrocracking catalyst that produces high-aromatic naphtha. The preparation method of this invention enables the hydrocracking catalyst to have a suitable specific surface area and pore size, improves catalytic activity while reducing energy consumption, and achieves the goal of producing high-aromatic naphtha in hydrocracking catalysts.

[0012] To achieve the above objectives, the present invention provides a method for preparing a hydrocracking catalyst that yields high-aromatic naphtha, the method comprising the following steps:

[0013] (1) Weigh out the mixed molecular sieve Y / SAPO-34 / ZSM-5 and ball mill it until uniform. Place it in a constant temperature water bath and add the bottom liquid. While stirring, add aluminum sulfate solution and ammonia water in a co-current flow to generate the precursor. Aging is performed. Water glass solution is added for the second aging. Composite solvent is added dropwise and the third aging is performed under stirring. Place it in a self-pressurized kettle for crystallization under autogenous pressure. Take out the crystallized product, wash, filter, dry and calcine it to obtain the modified molecular sieve oxide material. The modified molecular sieve oxide material is pulped and recorded as mixed slurry A.

[0014] (2) Dissolve tungsten salt and nickel salt in water, and after they are mixed evenly, add a complexing agent to obtain a metal complex solution, which is called reagent B.

[0015] (3) Add reagent B slowly to the mixed slurry A, stir evenly, let stand, and dry to obtain metal composite modified molecular sieve oxide;

[0016] (4) Alumina, metal composite modified molecular sieve oxide, nitric acid solution and guar powder are mixed evenly, extruded into strips, dried and calcined to obtain hydrocracking catalyst.

[0017] In the preparation method of the present invention, the Y / SAPO-34 / ZSM-5 mixed molecular sieve refers to a mixed molecular sieve formed by Y, SAPO-34, and ZSM-5.

[0018] In the preparation method of the present invention, the ratio of each component in the Y / SAPO-34 / ZSM-5 mixed molecular sieve is Y:SAPO-34:ZSM-5 = (75-90 wt%):(5-15 wt%):(2-10 wt%), preferably (75-85 wt%):(10-15 wt%):(5-10 wt%).

[0019] In the preparation method of the present invention, the base liquid is at least one of deionized water, ethanol, propanol, and isopropanol, preferably at least one of deionized water and ethanol.

[0020] In the preparation method of the present invention, in step (2), the tungsten salt is calculated as tungsten oxide, and the amount of tungsten oxide added accounts for 15 to 35 wt% of the mass of the modified molecular sieve oxide material, preferably 20 to 35 wt%.

[0021] In the preparation method of the present invention, in step (2), the nickel salt is calculated as nickel oxide, and the amount of nickel oxide added accounts for 5 to 10 wt% of the mass of the modified molecular sieve oxide material, preferably 6 to 8 wt%.

[0022] In the preparation method of this invention, in step (2), this invention does not particularly limit the operating conditions for dissolving tungsten salt and nickel salt in water. Preferably, the dissolution of tungsten salt and nickel salt in water is carried out at a temperature of 75-95°C. Furthermore, phosphoric acid can be added during the dissolution of tungsten salt and nickel salt in water to promote their dissolution. However, this invention does not particularly limit the amount of phosphoric acid added. The amount of phosphoric acid added is, for example, but not limited to, 2-5 wt% of the mass of the modified molecular sieve oxide material.

[0023] In the preparation method of the present invention, in step (2), the complexing agent is at least one of ethylenediaminetetraacetic acid, citric acid, and sodium ethylenediaminetetramethylene phosphate; the amount of the complexing agent added accounts for 5 to 30 wt% of the mass of the modified molecular sieve oxide material, preferably 15 to 25 wt%.

[0024] In the preparation method of the present invention, in step (1), the mass ratio of aluminum sulfate, ammonia, water glass and mixed molecular sieve is Al2O3:NH3:SiO2:molecular sieve = 1:(0.05~0.25):(1~2.2):(1.2~2.2), preferably 1:(0.1~0.25):(1~1.5):(1.5~2).

[0025] In the preparation method of the present invention, in step (1), the amount of the composite solvent added is 8 to 25 wt% of the mass of Al2O3 in the precursor.

[0026] The preparation method of the present invention uses a composite solvent obtained by mixing an organic acid, an inorganic acid, and an auxiliary agent, wherein the mass ratio of the organic acid, the inorganic acid, and the auxiliary agent is (2.5-6):(0.5-2):1.

[0027] The preparation method of the present invention uses tartaric acid, oxalic acid, and malic acid as the organic acid, phosphoric acid, nitric acid, and sulfuric acid as the inorganic acid, and citric acid as the auxiliary agent.

[0028] In the preparation method of the present invention, the temperature of the third aging is 20-85℃ and the stirring rate is 20-200 r / min.

[0029] The preparation method of this invention uses a hydrocracking catalyst with a specific surface area of ​​280–320 m². 2 / g, pore volume is 0.27~0.40mL / g, pore size is 7.8~10.2nm.

[0030] In the preparation method of this invention, in step (4), the amount of nitric acid solution added is based on nitric acid and is 2.5%-5% of the mass of the hydrocracking catalyst.

[0031] In the preparation method of this invention, in step (4), the amount of alumina added is 25%-35% of the mass of the hydrocracking catalyst.

[0032] In the preparation method of this invention, the amount of guar gum powder added in step (4) is not particularly limited, including but not limited to 3-5% of the mass of the hydrocracking catalyst.

[0033] In the preparation method of this invention, in step (4), the amount of metal composite modified molecular sieve oxide added is 55%-65% of the mass of the hydrocracking catalyst.

[0034] In the preparation method of the present invention, the shape of the extruded strip after step (4) is not particularly limited, and it can be at least one of cylindrical, clover and four-leaf clover shapes.

[0035] In the preparation method of the present invention, the conditions of the water bath in step (1) are not particularly limited, including but not limited to: a temperature of 35-60℃.

[0036] In the preparation method of the present invention, the aging conditions in step (1) are not particularly limited, including but not limited to: a temperature of 50-85°C and a time of 1-3 hours.

[0037] In the preparation method of the present invention, the conditions for the second aging in step (1) are not particularly limited, including but not limited to: temperature of 35-60℃ and time of 1h-3h.

[0038] In the preparation method of the present invention, the conditions for the third aging in step (1) are not particularly limited, including but not limited to: temperature of 35-85℃ and time of 1h-3h.

[0039] In the preparation method of the present invention, the crystallization conditions in step (1) are not particularly limited, including but not limited to: a temperature of 100-120°C and a time of 12-24h.

[0040] In the preparation method of the present invention, the drying conditions in step (1) are not particularly limited, including but not limited to: a temperature of 100-120℃ and a time of 2h-4h.

[0041] In the preparation method of the present invention, the calcination conditions in step (1) are not particularly limited, including but not limited to: a temperature of 450-550℃ and a time of 3-5h.

[0042] In the preparation method of the present invention, the standing conditions in step (3) are not particularly limited, including but not limited to: a time of 3h-6h.

[0043] In the preparation method of the present invention, the drying conditions in step (3) are not particularly limited, including but not limited to: a temperature of 100-120℃ and a time of 2h-4h.

[0044] In the preparation method of the present invention, the drying conditions in step (4) are not particularly limited, including but not limited to: a temperature of 100-120℃ and a time of 2h-4h.

[0045] In the preparation method of the present invention, the calcination conditions in step (4) are not particularly limited, including but not limited to: a temperature of 450-550℃ and a time of 3-5h.

[0046] The present invention has at least the following beneficial effects:

[0047] (1) The preparation method of the present invention uses a one-step synthesis of metal composite molecular sieve support material, and adjusts the pore structure of the composite molecular sieve material by adding a composite solvent. The pore size of the hydrocracking catalyst can be adjusted to a wider range, eliminating the impregnation process of metal components in the preparation of hydrocracking catalyst and reducing energy consumption. The catalyst obtained by the preparation method of the present invention is applied to the hydrocracking reaction of wax oil to achieve the maximum production of high aromatic naphtha.

[0048] (2) The preparation method of the present invention involves adding Y / SAPO-34 / ZSM-5 to the base liquid, then adding aluminum sulfate solution and ammonia water to generate a precursor, and then adding water glass solution to form a ladder-like pore structure, which helps macromolecular aromatic hydrocarbons diffuse into the pores and combine with the acid center to carry out hydrocracking reaction.

[0049] (3) The modified Y / SAPO-34 / ZSM-5 composite molecular sieve oxide material synthesized by the preparation method of the present invention has a high specific surface area of ​​551 m². 2 It contains abundant micro-meso-macropores and large pore volume, which is beneficial for mass and heat transfer between reactants and products.

[0050] (4) The hydrocracking catalyst synthesized by the preparation method of the present invention is used to produce more high aromatic naphtha with a naphtha yield of ≥55wt% and C6~C10 aromatic potential of ≥47%.

[0051] (5) The addition of a composite solvent in this invention can increase the specific surface area of ​​the metal composite modified molecular sieve oxide and enrich its pore structure. Compared with the method without the addition of a composite solvent, the metal composite modified molecular sieve oxide synthesized by this invention has a higher specific surface area, contains abundant micro-meso-macropores and a larger pore volume, which is beneficial to the mass and heat transfer of reactants and products. Attached Figure Description

[0052] Figure 1 The image shows the XRD pattern of the modified molecular sieve oxide material obtained in Example 1.

[0053] Figure 2 The image shows the adsorption isotherm curve of the modified molecular sieve oxide material obtained in Example 1.

[0054] Figure 3 This is a pore size distribution diagram of the modified molecular sieve oxide material obtained in Example 1. Detailed Implementation

[0055] The following detailed description of specific embodiments of the present invention, in conjunction with the accompanying drawings, aims to make the technical solution of the present invention easier to understand and master. However, the present invention is not limited thereto. Unless otherwise specified, the experimental methods in the following embodiments are conventional methods; the reagents and materials mentioned, unless otherwise specified, can be obtained commercially. Specifically, aluminum sulfate (Shandong Aluminum Industry Research Institute, industrial grade), water glass (Beijing Hongxing Sodium Silicate Factory), ammonium metatungstate (Merck reagent, WO3 content 85%), basic nickel carbonate (NiCO3·2Ni(OH)2·4H2O, industrial grade), ZSM-35 molecular sieve (Innochem brand, silicon-to-aluminum ratio 19), tartaric acid (Innochem brand, purity ≥99%), and citric acid (Innochem brand, purity 99%).

[0056] Analytical testing methods: Specific surface area and pore volume were tested on an ASAP2020M specific surface area and porosity analyzer manufactured by Micromeritics. Specific surface area was calculated according to the BET method; pore volume was calculated according to the BJH method.

[0057] Example 1

[0058] (1) Weigh 6.39g of Y molecular sieve, 1.28g of SAPO-34 molecular sieve, and 0.85g of ZSM-5 molecular sieve according to Y / SAPO-34 / ZSM-5 = 75wt%: 15wt%: 10wt% and place them in a ball mill. The ball milling speed is 400r / min. The mixture is ball-milled until uniform to obtain a mixed molecular sieve. Then, place it in a constant temperature water bath at 35℃ and add a certain volume of deionized water. While stirring, add 232.5g of 20% aluminum sulfate solution and 350mL of 0.3mol / L ammonia solution to generate a precursor. After aging at 60℃ for 1h, add 35.5g of water glass solution (SiO2 content 20wt%) through a feed pump and continue aging at 60℃ for 1h. The mass ratio of the feed is Al2O3:NH3:SiO2:molecular sieve = 1:0.25:1:1.2. After aging, 1.78g of a composite solvent was added dropwise, wherein the mass ratio of tartaric acid:phosphoric acid:citric acid in the composite solvent was 6:2:1. The aging was continued at 60℃ for 3 hours under stirring. The product was then placed in a self-pressurized autoclave and crystallized at 120℃ for 12 hours under autogenous pressure. The crystallized product was taken out, washed, filtered, dried at 120℃ for 2 hours, and calcined at 540℃ for 3 hours to obtain the modified molecular sieve oxide material. The modified molecular sieve oxide material was then pulped and denoted as mixed slurry A1.

[0059] (2) To prepare a metal complex solution, mix 4.85g of ammonium metatungstate and 2.86g of basic nickel carbonate and dissolve them in deionized water at 95℃. Add 1.1g of phosphoric acid and after mixing evenly, add 3.41g of ethylenediaminetetraacetic acid, which is designated as reagent B1.

[0060] (3) Add reagent B1 slowly to the mixed slurry A1, stir for 3 hours, and dry at 120°C for 2 hours to obtain metal composite modified molecular sieve oxide.

[0061] (4) Take 20.45g of metal composite modified molecular sieve oxide, 7.1g of alumina and 0.85g of guar gum powder and mix them evenly. Add nitric acid solution dropwise. The nitric acid solution is prepared by dissolving 1.14g of concentrated nitric acid (96wt%) in 16.4g of deionized water. Extrude into strips, dry at 100℃ for 3h, and calcine at 500℃ for 4h to obtain catalyst C1.

[0062] Example 2

[0063] (1) Weigh 6.39g of Y molecular sieve, 1.28g of SAPO-34 molecular sieve, and 0.85g of ZSM-5 molecular sieve according to Y / SAPO-34 / ZSM-5 = 75wt%: 15wt%: 10wt% and place them in a ball mill. The ball milling speed is 400r / min. The mixture is ball-milled until uniform to obtain a mixed molecular sieve. Then, place it in a 35℃ constant temperature water bath and add a certain volume of deionized water. While stirring, add 232.5g of 20% aluminum sulfate solution and 350mL of 0.3mol / L ammonia solution to generate a precursor. After aging at 60℃ for 1h, add 35.5g of water glass solution (SiO2 content 20wt%) through a feed pump and continue aging at 60℃ for 1h. The mass ratio of the feed is Al2O3:NH3:SiO2:molecular sieve = 1:0.25:1:1.2. After aging, 1.07g of composite solvent was added dropwise, wherein the mass ratio of tartaric acid:phosphoric acid:citric acid in the composite solvent was 4.5:1:1. The aging continued at 60℃ for 3h under stirring. The product was then placed in a self-pressurized autoclave and crystallized at 120℃ for 12h under autogenous pressure. The crystallized product was taken out, washed, filtered, dried at 100℃ for 2h, and calcined at 540℃ for 3h to obtain the modified molecular sieve oxide material. The modified molecular sieve oxide material was then pulped and denoted as mixed slurry A2.

[0064] (2) To prepare a metal complex solution, mix 4.85g of ammonium metatungstate and 2.86g of basic nickel carbonate and dissolve them in deionized water at 75℃. Add 1.1g of phosphoric acid and after mixing evenly, add 3.41g of ethylenediaminetetraacetic acid, which is designated as reagent B2.

[0065] (3) Slowly add reagent B2 to the mixed slurry A2, stir for 3 hours, and dry at 100°C for 2 hours to obtain metal composite modified molecular sieve oxide.

[0066] (4) Take 20.45g of metal composite modified molecular sieve oxide, 7.1g of alumina and 0.85g of guar gum powder and mix them evenly. Add nitric acid solution dropwise. The nitric acid solution is prepared by dissolving 1.14g of concentrated nitric acid (96wt%) in 16.4g of deionized water. Extrude into strips, dry at 100℃ for 3h, and calcine at 500℃ for 4h to obtain catalyst C2.

[0067] Example 3

[0068] (1) Weigh 6.39g of Y molecular sieve, 1.28g of SAPO-34 molecular sieve, and 0.85g of ZSM-5 molecular sieve according to the ratio of Y / SAPO-34 / ZSM-5 = 75wt%: 15wt%: 10wt%, and place them in a ball mill. The ball milling speed is 400r / min. The mixture is then ball-milled until homogeneous to obtain a mixed molecular sieve. Subsequently, it is placed in a 35℃ constant temperature water bath with a certain volume of deionized water added. While stirring, 232.5g of 20% aluminum sulfate solution and 350mL of 0.3mol / L ammonia solution are added concurrently to generate a precursor. After aging at 60℃ for 1h, 35.5g of water glass solution (S) is added through a feed pump. The product (containing 20 wt% iO2) was aged at 60°C for 1 hour with a feed ratio of Al2O3:NH3:SiO2:molecular sieve = 1:0.25:1:1.2. After aging at 60°C, 0.57 g of a composite solvent was added dropwise, wherein the mass ratio of tartaric acid:phosphoric acid:citric acid in the composite solvent was 2.5:0.5:1. The product was aged for another 3 hours under stirring. It was then placed in a self-pressurized autoclave and crystallized at 120°C for 12 hours under autogenous pressure. The crystallized product was then removed, washed, filtered, dried at 120°C for 2 hours, and calcined at 540°C for 3 hours to obtain the modified molecular sieve oxide material. The modified molecular sieve oxide material was then pulped and denoted as mixed slurry A3.

[0069] (2) To prepare a metal complex solution, mix 8.49 g of ammonium metatungstate and 3.57 g of basic nickel carbonate and dissolve them in deionized water at 85 °C. After mixing evenly, add 3.41 g of ethylenediaminetetraacetic acid, which is designated as reagent B3.

[0070] (3) Add reagent B3 slowly to the mixed slurry A3, stir for 3 hours, and dry at 120°C for 2 hours to obtain metal composite modified molecular sieve oxide.

[0071] (4) Take 20.45g of metal composite modified molecular sieve oxide, 7.1g of alumina and 0.85g of guar gum powder and mix them evenly. Add nitric acid solution dropwise. The nitric acid solution is prepared by dissolving 1.14g of concentrated nitric acid (96wt%) in 16.4g of deionized water. Extrude into strips, dry at 100℃ for 3h, and calcine at 500℃ for 4h to obtain catalyst C3.

[0072] Example 4

[0073] (1) Weigh 9.05g of Y molecular sieve, 1.07g of SAPO-34 molecular sieve, and 0.53g of ZSM-5 molecular sieve according to the ratio Y / SAPO-34 / ZSM-5 = 85wt%: 10wt%: 5wt%, and place them in a ball mill. The ball milling speed is 400r / min. Mix the mixture until homogeneous to obtain a mixed molecular sieve. Then, place it in a 35℃ constant temperature water bath and add a certain volume of deionized water. While stirring, add 232.5g of 20% aluminum sulfate solution and 350mL of 0.3mol / L ammonia solution in a co-current flow to generate a precursor. After aging at 60℃ for 1h, add 53.25g of water glass solution (SiO2 content...) through a feed pump. 20wt%), and continued aging at 60℃ for 1h, denoted as mixed gel A, with a feed mass ratio of Al2O3:NH3:SiO2:molecular sieve = 1:0.25:1.5:1.5. After aging at 60℃, 1.78g of composite solvent was added dropwise, wherein the mass ratio of tartaric acid:phosphoric acid:citric acid in the composite solvent was 6:2:1. Under stirring conditions, aging continued at 60℃ for 3h, and then placed in a self-pressurized autoclave for crystallization at 120℃ for 12h under autogenous pressure. The crystallized product was taken out, washed, filtered, dried at 120℃ for 2h, and calcined at 540℃ for 3h to obtain modified molecular sieve oxide material; the modified molecular sieve oxide material was then pulped, denoted as mixed slurry A4.

[0074] (2) To prepare a metal complex solution, mix 6.07g of ammonium metatungstate and 3.57g of basic nickel carbonate and dissolve them in deionized water at 95℃. Add 0.45g of phosphoric acid and after mixing evenly, add 4.26g of ethylenediaminetetraacetic acid, which is designated as reagent B4.

[0075] (3) Add reagent B4 slowly to the mixed slurry A4, stir for 3 hours, and dry at 120°C for 2 hours to obtain metal composite modified molecular sieve oxide.

[0076] (4) Take 24.83g of metal composite modified molecular sieve oxide, 8.9g of alumina and 1.77g of guar powder and mix them evenly. Add nitric acid solution dropwise. The nitric acid solution is prepared by dissolving 1.07g of concentrated nitric acid (96wt%) in 19.9g of deionized water. Extrude into strips, dry at 100℃ for 3h, and calcine at 500℃ for 4h to obtain catalyst C4.

[0077] Example 5

[0078] (1) Weigh 10.65g of Y molecular sieve, 2.13g of SAPO-34 molecular sieve, and 1.42g of ZSM-5 molecular sieve according to Y / SAPO-34 / ZSM-5 = 75wt%: 15wt%: 10wt% and place them in a ball mill. The ball milling speed is 400r / min. The mixture is ball-milled until uniform to obtain a mixed molecular sieve. Then, place it in a 35℃ constant temperature water bath and add a certain volume of deionized water. While stirring, add 232.5g of 20% aluminum sulfate solution and 250mL of 0.3mol / L ammonia solution to generate a precursor. After aging at 60℃ for 1h, add 53.25g of water glass solution (SiO2 content 20wt%) through a feed pump and continue aging at 60℃ for 1h. The mass ratio of the feed is Al2O3:NH3:SiO2:molecular sieve = 1:0.18:1.5:2. After aging, 1.78g of a composite solvent was added dropwise, wherein the mass ratio of tartaric acid:phosphoric acid:citric acid in the composite solvent was 6:2:1. The aging continued at 60℃ for 3h under stirring. The product was then placed in a self-pressurized autoclave and crystallized at 120℃ for 12h under autogenous pressure. The crystallized product was taken out, washed, filtered, dried at 120℃ for 2h, and calcined at 540℃ for 3h to obtain the modified molecular sieve oxide material. The modified molecular sieve oxide material was then pulped and denoted as mixed slurry A5.

[0079] (2) To prepare a metal complex solution, mix 6.83g of ammonium metatungstate and 5.03g of basic nickel carbonate and dissolve them in deionized water at 95℃. Add 0.91g of phosphoric acid and after mixing evenly, add 7.98g of ethylenediaminetetraacetic acid, which is designated as reagent B5.

[0080] (3) Add reagent B5 slowly to the mixed slurry A5, stir for 3 hours, and dry at 120°C for 2 hours to obtain metal composite modified molecular sieve oxide.

[0081] (4) Take 33.16g of metal composite modified molecular sieve oxide, 11.8g of alumina and 2.37g of guar gum powder and mix them evenly. Add nitric acid solution dropwise. The nitric acid solution is prepared by dissolving 1.42g of concentrated nitric acid (96wt%) in 26.5g of deionized water. Extrude into strips, dry at 100℃ for 3h, and calcine at 500℃ for 4h to obtain catalyst C5.

[0082] Example 6

[0083] (1) Weigh 9.05g of Y molecular sieve, 1.07g of SAPO-34 molecular sieve, and 0.53g of ZSM-5 molecular sieve according to Y / SAPO-34 / ZSM-5 = 85wt%: 10wt%: 5wt%, and place them in a ball mill. The ball milling speed is 400r / min. The mixture is ball-milled until homogeneous to obtain a mixed molecular sieve. Then, place it in a 35℃ constant temperature water bath and add a certain volume of deionized water. While stirring, add 232.5g of 20% aluminum sulfate solution and 350mL of 0.3mol / L ammonia solution to generate a precursor. After aging at 60℃ for 1h, add 35.5g of water glass solution (SiO2 content 20wt%) through a feed pump and continue aging at 60℃ for 1h. The mass ratio of the feed is Al2O3:NH3:SiO2:molecular sieve = 1:0.25:1:1.5. After aging, 1.78g of a composite solvent was added dropwise, wherein the mass ratio of tartaric acid:phosphoric acid:citric acid in the composite solvent was 6:2:1. The aging continued at 60℃ for 3 hours under stirring. The product was then placed in a self-pressurized autoclave and crystallized at 120℃ for 12 hours under autogenous pressure. The crystallized product was then removed, washed, filtered, dried at 100℃ for 2 hours, and calcined at 540℃ for 3 hours to obtain the modified molecular sieve oxide material. The modified molecular sieve oxide material was then pulped and denoted as mixed slurry A6.

[0084] (2) To prepare a metal complex solution, mix 5.31g of ammonium metatungstate and 3.12g of basic nickel carbonate and dissolve them in deionized water at 95℃. Add 1.1g of phosphoric acid and after mixing evenly, add 3.73g of ethylenediaminetetraacetic acid, which is designated as reagent B6.

[0085] (3) Add reagent B6 slowly to the mixed slurry A6, stir for 3 hours, and dry at 100°C for 3 hours to obtain metal composite modified molecular sieve oxide.

[0086] (4) Take 24.83g of metal composite modified molecular sieve oxide, 8.9g of alumina and 1.77g of guar powder and mix them evenly. Add nitric acid solution dropwise. The nitric acid solution is prepared by dissolving 1.07g of concentrated nitric acid (96wt%) in 19.9g of deionized water. Extrude into strips, dry at 100℃ for 3h, and calcine at 500℃ for 4h to obtain catalyst C6.

[0087] Example 7

[0088] (1) Weigh 7.67g of Y molecular sieve, 0.43g of SAPO-34 molecular sieve, and 0.43g of ZSM-5 molecular sieve according to Y / SAPO-34 / ZSM-5 = 90wt%: 5wt%: 5wt% and place them in a ball mill. The ball milling speed is 400r / min. The mixture is ball-milled until uniform to obtain a mixed molecular sieve. Then, place it in a 35℃ constant temperature water bath and add a certain volume of deionized water. While stirring, add 232.5g of 20% aluminum sulfate solution and 350mL of 0.3mol / L ammonia solution to generate a precursor. After aging at 60℃ for 1h, add 35.5g of water glass solution (SiO2 content 20wt%) through a feed pump and continue aging at 60℃ for 1h. The mass ratio of the feed is Al2O3:NH3:SiO2:molecular sieve = 1:0.25:1:1.2. After aging, 1.78g of a composite solvent was added dropwise, wherein the mass ratio of tartaric acid:phosphoric acid:citric acid in the composite solvent was 6:2:1. The aging was continued at 60℃ for 3 hours under stirring. The product was then placed in a self-pressurized autoclave and crystallized at 120℃ for 12 hours under autogenous pressure. The crystallized product was taken out, washed, filtered, dried at 120℃ for 2 hours, and calcined at 540℃ for 3 hours to obtain the modified molecular sieve oxide material. The modified molecular sieve oxide material was then pulped and denoted as mixed slurry A7.

[0089] (2) To prepare a metal complex solution, mix 8.49g of ammonium metatungstate and 3.57g of basic nickel carbonate and dissolve them in deionized water at 95℃. Add 1.1g of phosphoric acid and after mixing evenly, add 3.41g of ethylenediaminetetraacetic acid. This solution is designated as reagent B7.

[0090] (3) Add reagent B7 slowly to the mixed slurry A7, stir for 3 hours, and dry at 120°C for 3 hours to obtain metal composite modified molecular sieve oxide.

[0091] (4) Take 20.45g of metal composite modified molecular sieve oxide, 7.1g of alumina and 0.85g of guar gum powder and mix them evenly. Add nitric acid solution dropwise. The nitric acid solution is prepared by dissolving 1.14g of concentrated nitric acid (96wt%) in 16.4g of deionized water. Extrude into strips, dry at 100℃ for 3h, and calcine at 500℃ for 4h to obtain catalyst C7.

[0092] Example 8

[0093] (1) Weigh 7.67g of Y molecular sieve, 0.68g of SAPO-34 molecular sieve, and 0.17g of ZSM-5 molecular sieve according to Y / SAPO-34 / ZSM-5 = 90wt%: 8wt%: 2wt%, and place them in a ball mill. The ball milling speed is 400r / min. The mixture is ball-milled until homogeneous to obtain a mixed molecular sieve. Then, place it in a 35℃ constant temperature water bath and add a certain volume of deionized water. While stirring, add 232.5g of 20% aluminum sulfate solution and 350mL of 0.3mol / L ammonia solution to generate a precursor. After aging at 60℃ for 1h, add 35.5g of water glass solution (SiO2 content 20wt%) through a feed pump and continue aging at 60℃ for 1h. The mass ratio of the feed is Al2O3:NH3:SiO2:molecular sieve = 1:0.25:1:1.2. After aging, 1.78g of a composite solvent was added dropwise, wherein the mass ratio of tartaric acid:phosphoric acid:citric acid in the composite solvent was 6:2:1. The aging was continued at 60℃ for 3 hours under stirring. The product was then placed in a self-pressurized autoclave and crystallized at 120℃ for 12 hours under autogenous pressure. The crystallized product was taken out, washed, filtered, dried at 120℃ for 2 hours, and calcined at 540℃ for 3 hours to obtain the modified molecular sieve oxide material. The modified molecular sieve oxide material was then pulped and denoted as mixed slurry A8.

[0094] (2) To prepare a metal complex solution, mix 8.49g of ammonium metatungstate and 2.65g of nickel nitrate in deionized water at 95℃, add 1.1g of phosphoric acid, and after mixing evenly, add 3.41g of citric acid. This solution is called reagent B8.

[0095] (3) Add reagent B8 slowly to the mixed slurry A8, stir for 3 hours, and dry at 120°C for 3 hours to obtain metal composite modified molecular sieve oxide.

[0096] (4) Take 20.45g of metal composite modified molecular sieve oxide, 7.1g of alumina and 0.85g of guar gum powder and mix them evenly. Add nitric acid solution dropwise. The nitric acid solution is prepared by dissolving 1.14g of concentrated nitric acid (96wt%) in 16.4g of deionized water. Extrude into strips, dry at 100℃ for 3h and calcine at 500℃ for 4h to obtain catalyst C8.

[0097] Example 9

[0098] (1) Weigh 6.39g of Y molecular sieve, 1.28g of SAPO-34 molecular sieve, and 0.85g of ZSM-5 molecular sieve according to Y / SAPO-34 / ZSM-5 = 75wt%: 15wt%: 10wt% and place them in a ball mill. The ball milling speed is 400r / min. The mixture is ball-milled until uniform to obtain a mixed molecular sieve. Then, place it in a 35℃ constant temperature water bath and add a certain volume of ethanol solution. While stirring, add 232.5g of 20% aluminum sulfate solution and 350mL of 0.3mol / L ammonia solution to generate a precursor. After aging at 60℃ for 1h, add 35.5g of water glass solution (SiO2 content 20wt%) through a feed pump and continue aging at 60℃ for 1h. The mass ratio of the feed is Al2O3:NH3:SiO2:molecular sieve = 1:0.25:1:1.2. After aging, 1.78g of a composite solvent was added dropwise, wherein the mass ratio of tartaric acid:phosphoric acid:citric acid in the composite solvent was 6:2:1. The aging was continued at 60℃ for 3 hours under stirring. The product was then placed in a self-pressurized autoclave and crystallized at 120℃ for 12 hours under autogenous pressure. The crystallized product was taken out, washed, filtered, dried at 120℃ for 2 hours, and calcined at 540℃ for 3 hours to obtain the modified molecular sieve oxide material. The modified molecular sieve oxide material was then pulped and denoted as mixed slurry A9.

[0099] (2) To prepare a metal complex solution, mix 4.85g of ammonium metatungstate and 2.86g of basic nickel carbonate and dissolve them in deionized water at 95℃. Add 1.1g of phosphoric acid and after mixing evenly, add 3.41g of ethylenediaminetetraacetic acid, which is designated as reagent B9.

[0100] (3) Add reagent B9 slowly to the mixed slurry A9, stir for 3 hours, and dry at 120°C for 3 hours to obtain metal composite modified molecular sieve oxide.

[0101] (4) Take 20.45g of metal composite modified molecular sieve oxide, 7.1g of alumina and 0.85g of guar gum powder and mix them evenly. Add nitric acid solution dropwise. The nitric acid solution is prepared by dissolving 1.14g of concentrated nitric acid (96wt%) in 16.4g of deionized water. Extrude into strips, dry at 100℃ for 3h, and calcine at 500℃ for 4h to obtain catalyst C9.

[0102] Example 10

[0103] (1) Weigh 6.39g of Y molecular sieve, 1.28g of SAPO-34 molecular sieve, and 0.85g of ZSM-5 molecular sieve according to Y / SAPO-34 / ZSM-5 = 75wt%: 15wt%: 10wt% and place them in a ball mill. The ball milling speed is 400r / min. The mixture is ball-milled until uniform to obtain a mixed molecular sieve. Then, place it in a 35℃ constant temperature water bath and add a certain volume of deionized water. While stirring, add 232.5g of 20% aluminum sulfate solution and 350mL of 0.3mol / L ammonia solution to generate a precursor. After aging at 60℃ for 1h, add 35.5g of water glass solution (SiO2 content 20wt%) through a feed pump and continue aging at 60℃ for 1h. The mass ratio of the feed is Al2O3:NH3:SiO2:molecular sieve = 1:0.25:1:1.2. After aging, 1.78g of a composite solvent was added dropwise, wherein the mass ratio of tartaric acid:phosphoric acid:citric acid in the composite solvent was 6:2:1. The aging was continued at 60℃ for 3 hours under stirring. The product was then placed in a self-pressurized autoclave and crystallized at 120℃ for 12 hours under autogenous pressure. The crystallized product was taken out, washed, filtered, dried at 120℃ for 2 hours, and calcined at 540℃ for 3 hours to obtain the modified molecular sieve oxide material. The modified molecular sieve oxide material was then pulped and denoted as mixed slurry A10.

[0104] (2) To prepare a metal complex solution, mix 4.85g of ammonium metatungstate and 2.86g of basic nickel carbonate and dissolve them in deionized water at 95℃. Add 1.1g of phosphoric acid and after mixing evenly, add 3.41g of sodium ethylenediaminetetramethylene phosphate, which is designated as reagent B10.

[0105] (3) Slowly add reagent B10 to the mixed slurry A10, stir for 3 hours, and dry at 120°C for 3 hours to obtain metal composite modified molecular sieve oxide.

[0106] (4) Take 20.45g of metal composite modified molecular sieve oxide, 7.1g of alumina and 0.85g of guar gum powder and mix them evenly. Add nitric acid solution dropwise. The nitric acid solution is prepared by dissolving 1.14g of concentrated nitric acid (96wt%) in 16.4g of deionized water. Extrude into strips, dry at 100℃ for 3h, and calcine at 500℃ for 4h to obtain catalyst C10.

[0107] Example 11

[0108] (1) Weigh 6.39g of Y molecular sieve, 1.28g of SAPO-34 molecular sieve, and 0.85g of ZSM-5 molecular sieve according to Y / SAPO-34 / ZSM-5 = 75wt%: 15wt%: 10wt% and place them in a ball mill. The ball milling speed is 400r / min. The mixture is ball-milled until uniform to obtain a mixed molecular sieve. Then, place it in a 35℃ constant temperature water bath and add a certain volume of deionized water. While stirring, add 232.5g of 20% aluminum sulfate solution and 350mL of 0.3mol / L ammonia solution to generate a precursor. After aging at 60℃ for 1h, add 78.1g of water glass solution (SiO2 content 20wt%) through a feed pump and continue aging at 60℃ for 1h. The mass ratio of the feed is Al2O3:NH3:SiO2:molecular sieve = 1:0.25:2.2:1.2. After aging, 1.78g of a composite solvent was added dropwise, wherein the mass ratio of tartaric acid:phosphoric acid:citric acid in the composite solvent was 6:2:1. The aging was continued at 60℃ for 3 hours under stirring. The product was then placed in a self-pressurized autoclave and crystallized at 120℃ for 12 hours under autogenous pressure. The crystallized product was taken out, washed, filtered, dried at 120℃ for 2 hours, and calcined at 540℃ for 3 hours to obtain the modified molecular sieve oxide material. The modified molecular sieve oxide material was then pulped and denoted as mixed slurry A11.

[0109] (2) To prepare a metal complex solution, mix 11.68g of ammonium metatungstate and 4.91g of basic nickel carbonate and dissolve them in deionized water at 95℃. Add 1.1g of phosphoric acid and after mixing evenly, add 4.68g of ethylenediaminetetraacetic acid, which is designated as reagent B11.

[0110] (3) Add reagent B11 slowly to the mixed slurry A11, stir for 3 hours, and dry at 120°C for 3 hours to obtain metal composite modified molecular sieve oxide.

[0111] (4) Take 20.45g of metal composite modified molecular sieve oxide, 7.1g of alumina and 0.85g of guar gum powder and mix them evenly. Add nitric acid solution dropwise. The nitric acid solution is prepared by dissolving 1.14g of concentrated nitric acid (96wt%) in 16.4g of deionized water. Extrude into strips, dry at 100℃ for 3h, and calcine at 500℃ for 4h to obtain catalyst C11.

[0112] Example 12

[0113] (1) Weigh 6.39g of Y molecular sieve, 1.28g of SAPO-34 molecular sieve, and 0.85g of ZSM-5 molecular sieve according to Y / SAPO-34 / ZSM-5 = 75wt%: 15wt%: 10wt% and place them in a ball mill. The ball milling speed is 400r / min. The mixture is ball-milled until uniform to obtain a mixed molecular sieve. Then, place it in a 35℃ constant temperature water bath and add a certain volume of deionized water. While stirring, add 232.5g of 20% aluminum sulfate solution and 350mL of 0.3mol / L ammonia solution to generate a precursor. After aging at 60℃ for 1h, add 78.1g of water glass solution (SiO2 content 20wt%) through a feed pump and continue aging at 60℃ for 1h. The mass ratio of the feed is Al2O3:NH3:SiO2:molecular sieve = 1:0.25:2.2:1.2. After aging, 1.78g of a composite solvent was added dropwise, wherein the mass ratio of oxalic acid:phosphoric acid:citric acid in the composite solvent was 6:2:1. The aging was continued at 60℃ for 3 hours under stirring. The product was then placed in a self-pressurized autoclave and crystallized at 120℃ for 12 hours under autogenous pressure. The crystallized product was taken out, washed, filtered, dried at 120℃ for 2 hours, and calcined at 540℃ for 3 hours to obtain the modified molecular sieve oxide material. The modified molecular sieve oxide material was then pulped and denoted as mixed slurry A12.

[0114] (2) To prepare a metal complex solution, mix 11.68g of ammonium metatungstate and 4.91g of basic nickel carbonate and dissolve them in deionized water at 95℃. Add 1.1g of phosphoric acid and after mixing evenly, add 4.68g of ethylenediaminetetraacetic acid, which is designated as reagent B12.

[0115] (3) Slowly add reagent B12 to the mixed slurry A12, stir for 3 hours, and dry at 120°C for 3 hours to obtain metal composite modified molecular sieve oxide.

[0116] (4) Take 20.45g of metal composite modified molecular sieve oxide, 7.1g of alumina and 0.85g of guar gum powder and mix them evenly. Add nitric acid solution dropwise. The nitric acid solution is prepared by dissolving 1.14g of concentrated nitric acid (96wt%) in 16.4g of deionized water. Extrude into strips, dry at 100℃ for 3h, and calcine at 500℃ for 4h to obtain catalyst C12.

[0117] Example 13

[0118] (1) Weigh 10.65g of Y molecular sieve, 2.13g of SAPO-34 molecular sieve, and 1.42g of ZSM-5 molecular sieve according to Y / SAPO-34 / ZSM-5 = 75wt%: 15wt%: 10wt% and place them in a ball mill. The ball milling speed is 400r / min. The mixture is ball-milled until uniform to obtain a mixed molecular sieve. Then, place it in a 35℃ constant temperature water bath and add a certain volume of deionized water. While stirring, add 232.5g of 20% aluminum sulfate solution and 350mL of 0.3mol / L ammonia solution to generate a precursor. After aging at 60℃ for 1h, add 71g of water glass solution (SiO2 content 20wt%) through a feed pump and continue aging at 60℃ for 1h. The mass ratio of the feed is Al2O3:NH3:SiO2:molecular sieve = 1:0.25:2.0:2. After aging, 1.78g of a composite solvent was added dropwise, wherein the mass ratio of tartaric acid:nitric acid:citric acid in the composite solvent was 6:2:1. The aging was continued at 60℃ for 3 hours under stirring. The product was then placed in a self-pressurized autoclave and crystallized at 120℃ for 12 hours under autogenous pressure. The crystallized product was taken out, washed, filtered, dried at 100℃ for 2 hours, and calcined at 540℃ for 3 hours to obtain the modified molecular sieve oxide material. The modified molecular sieve oxide material was then pulped and denoted as mixed slurry A13.

[0119] (2) To prepare a metal complex solution, mix 7.59g of ammonium metatungstate and 5.83g of nickel nitrate in deionized water at 95℃, add 1.1g of phosphoric acid, and after mixing evenly, add 3.55g of ethylenediaminetetraacetic acid, which is designated as reagent B13.

[0120] (3) Add reagent B13 slowly to the mixed slurry A13, stir for 3 hours, and dry at 120°C for 3 hours to obtain metal composite modified molecular sieve oxide.

[0121] (4) Take 20.45g of metal composite modified molecular sieve oxide, 7.1g of alumina and 0.85g of guar gum powder and mix them evenly. Add nitric acid solution dropwise. The nitric acid solution is prepared by dissolving 1.14g of concentrated nitric acid (96wt%) in 16.4g of deionized water. Extrude into strips, dry at 100℃ for 3h and calcine at 500℃ for 4h to obtain catalyst C13.

[0122] Example 14

[0123] (1) Weigh 6.39g of Y molecular sieve, 1.28g of SAPO-34 molecular sieve, and 0.85g of ZSM-5 molecular sieve according to Y / SAPO-34 / ZSM-5 = 75wt%: 15wt%: 10wt% and place them in a ball mill. The ball milling speed is 400r / min. The mixture is ball-milled until uniform to obtain a mixed molecular sieve. Then, place it in a 35℃ constant temperature water bath and add a certain volume of deionized water. While stirring, add 232.5g of 20% aluminum sulfate solution and 140mL of 0.3mol / L ammonia solution to generate a precursor. After aging at 60℃ for 1h, add 78.1g of water glass solution (SiO2 content 20wt%) through a feed pump and continue aging at 60℃ for 1h. The mass ratio of the feed is Al2O3:NH3:SiO2:molecular sieve = 1:0.10:2.2:1.2. After aging, 1.42g of a composite solvent was added dropwise, wherein the mass ratio of malic acid:nitric acid:citric acid in the composite solvent was 4.5:2:1. The aging was continued at 60℃ for 3 hours under stirring. The product was then placed in a self-pressurized autoclave and crystallized at 120℃ for 12 hours under autogenous pressure. The crystallized product was taken out, washed, filtered, dried at 120℃ for 2 hours, and calcined at 550℃ for 3 hours to obtain the modified molecular sieve oxide material. The modified molecular sieve oxide material was then pulped and denoted as mixed slurry A14.

[0124] (2) To prepare a metal complex solution, mix 11.68g of ammonium metatungstate and 4.91g of basic nickel carbonate and dissolve them in deionized water at 95℃. Add 1.1g of phosphoric acid and after mixing evenly, add 4.68g of ethylenediaminetetraacetic acid, which is designated as reagent B14.

[0125] (3) Add reagent B14 slowly to the mixed slurry A14, stir for 3 hours, and dry at 120°C for 3 hours to obtain metal composite modified molecular sieve oxide.

[0126] (4) Take 20.45g of metal composite modified molecular sieve oxide, 7.1g of alumina and 0.85g of guar gum powder and mix them evenly. Add nitric acid solution dropwise. The nitric acid solution is prepared by dissolving 1.14g of concentrated nitric acid (96wt%) in 16.4g of deionized water. Extrude into strips, dry at 100℃ for 3h and calcine at 500℃ for 4h to obtain catalyst C14.

[0127] Comparative Example 1

[0128] The difference from Example 1 is that no composite solvent was added.

[0129] (1) Weigh 6.39g of Y molecular sieve, 1.28g of SAPO-34 molecular sieve, and 0.85g of ZSM-5 molecular sieve according to Y / SAPO-34 / ZSM-5 = 75wt%: 15wt%: 10wt% and place them in a ball mill. The ball milling speed is 400r / min. The mixture is ball-milled until uniform to obtain a mixed molecular sieve. Then, place it in a 35℃ constant temperature water bath and add a certain volume of deionized water. While stirring, add 232.5g of 20% aluminum sulfate solution and 350mL of 0.3mol / L ammonia solution to generate a precursor. After aging at 60℃ for 1h, add 35.5g of water glass solution (SiO2 content 20wt%) through a feed pump. Continue aging at 60℃ for 1h. The mass ratio of the feed is Al2O3:NH3:SiO2:molecular sieve = 1:0.25:1:1.2. The product was aged at 60℃ for 3 hours under stirring conditions, then placed in a self-pressurized autoclave and crystallized at 120℃ for 12 hours under autogenous pressure. The crystallized product was then removed, washed, filtered, dried at 120℃ for 2 hours, and calcined at 540℃ for 3 hours to obtain the modified molecular sieve oxide material. The modified molecular sieve oxide material was then pulped and denoted as mixed slurry DA1.

[0130] (2) To prepare a metal complex solution, mix 4.85g of ammonium metatungstate and 2.86g of basic nickel carbonate and dissolve them in deionized water at 95℃. Add 1.1g of phosphoric acid and after mixing evenly, add 3.41g of ethylenediaminetetraacetic acid. This solution is called DB1 reagent.

[0131] (3) DB1 reagent was slowly added to the mixed slurry DA1, stirred for 3 hours, and dried at 120°C for 2 hours to obtain metal composite modified molecular sieve material.

[0132] (4) Take 20.45g of metal composite modified molecular sieve material, 7.1g of alumina and 0.85g of guar gum powder and mix them evenly. Add nitric acid solution dropwise. The nitric acid solution is prepared by dissolving 1.14g of concentrated nitric acid (96wt%) in 16.4g of deionized water. Extrude into strips, dry at 100℃ for 3h, and calcine at 500℃ for 4h to obtain catalyst DC1.

[0133] Comparative Example 2

[0134] (1) Weigh 6.39g of Y molecular sieve, 1.28g of SAPO-34 molecular sieve, and 0.85g of ZSM-5 molecular sieve according to Y / SAPO-34 / ZSM-5 = 75wt%: 15wt%: 10wt% and mix them until uniform to obtain a mixed molecular sieve. Then place it in a 35℃ constant temperature water bath and add a certain volume of deionized water. While stirring, add 232.5g of 20% aluminum sulfate solution and 350mL of 0.3mol / L ammonia solution to generate a precursor. After aging at 60℃ for 1h, add 35.5g of water glass solution (SiO2 content 20wt%) through a feed pump and continue aging at 60℃ for 1h. The mass ratio of the feed is Al2O3:NH3:SiO2:molecular sieve = 1:0.25:1:1.2. After aging, 1.78g of a composite solvent was added dropwise, wherein the mass ratio of tartaric acid:phosphoric acid:citric acid in the composite solvent was 6:2:1. The mixture was aged at 60℃ for 3 hours under stirring. The mixture was then placed in a self-pressurized autoclave and crystallized at 120℃ for 12 hours under autogenous pressure. The crystallized product was then removed, washed, filtered, dried at 120℃ for 2 hours, and calcined at 540℃ for 3 hours to obtain the modified molecular sieve material.

[0135] (2) To prepare a metal complex solution, mix 4.85g of ammonium metatungstate and 2.86g of basic nickel carbonate and dissolve them in deionized water at 95℃. Add 1.1g of phosphoric acid and after mixing evenly, add 3.41g of ethylenediaminetetraacetic acid. This solution is called DB1 reagent.

[0136] (3) Take 24.83g of modified molecular sieve material, 8.9g of alumina and 1.77g of guar gum powder from step (1) and mix them evenly. Add nitric acid solution dropwise. The nitric acid solution is prepared by dissolving 1.07g of concentrated nitric acid (96wt%) in 19.9g of deionized water. Extrude the mixture into strips, dry it at 100℃ for 3h, and calcine it at 500℃ for 4h to obtain the catalyst support.

[0137] (4) The DB1 reagent obtained in step (2) and the catalyst support obtained in step (3) were impregnated in equal volume according to the equal volume impregnation method, dried at 100℃ for 3h, and calcined at 500℃ for 4h to obtain catalyst DC2.

[0138] Table 1 Properties of Y / / SAPO-34 / ZSM-5 Modified Molecular Sieves Oxide Materials

[0139]

[0140] Example 15

[0141] This embodiment presents the evaluation results of the catalysts prepared in the examples and comparative examples during the hydrocracking of wax oil in a 200 mL fixed-bed hydrotreating unit. The catalyst loading was 100 mL, and sulfidation was performed using kerosene containing 2% carbon disulfide. The main properties of the feedstock are listed in Table 2, and the evaluation results are listed in Table 3.

[0142] Table 2 Properties of Wax Oil Raw Materials

[0143]

[0144]

[0145] Table 3 Results of hydrocracking reactions with different catalysts

[0146]

[0147]

[0148]

[0149] As can be seen from the results of Example 1 and Comparative Example 1 in Table 1, compared with the addition of no composite solvent, the addition of composite solvent in this invention can increase the specific surface area of ​​the metal composite modified molecular sieve oxide and enrich the pore structure.

[0150] The results in Table 3 show that the catalyst prepared by the method of the present invention can achieve high production of high aromatic naphtha in the hydrocracking reaction of wax oil.

[0151] This invention is not limited to the specific embodiments described above. Any changes or modifications made by those skilled in the art within the scope of this invention are covered by the patent scope of this invention.

Claims

1. A method for preparing a hydrocracking catalyst that yields high-aromatic naphtha, characterized in that, Includes the following steps: (1) Weigh out the mixed molecular sieve Y / SAPO-34 / ZSM-5 and ball mill it until uniform. Place it in a constant temperature water bath and add the bottom liquid. While stirring, add aluminum sulfate solution and ammonia water in a co-current flow to generate the precursor. Aging is performed. Water glass solution is added for the second aging. Composite solvent is added dropwise and the third aging is performed under stirring. Place it in a self-pressurized kettle for crystallization under autogenous pressure. Take out the crystallized product, wash, filter, dry and calcine it to obtain the modified molecular sieve oxide material. The modified molecular sieve oxide material is pulped and recorded as mixed slurry A. (2) Dissolve tungsten salt and nickel salt in water, and after they are mixed evenly, add a complexing agent to obtain a metal complex solution, which is called reagent B. (3) Add reagent B slowly to the mixed slurry A, stir evenly, let stand, and dry to obtain metal composite modified molecular sieve oxide; (4) Alumina, metal composite modified molecular sieve oxide, nitric acid solution and guar gum powder are mixed evenly, extruded into strips, dried and calcined to obtain hydrocracking catalyst; The proportions of each component in the Y / SAPO-34 / ZSM-5 mixed molecular sieve are Y:SAPO-34:ZSM-5 = (75-90 wt%): (5-15 wt%): (2-10 wt%). In step (1), the mass ratio of aluminum sulfate, ammonia, water glass and mixed molecular sieve is Al2O3:NH3:SiO2:molecular sieve = 1:(0.05~0.25):(1~2.2):(1.2~2.2); In step (1), the amount of the composite solvent added is 8-25 wt% of the mass of Al2O3 in the precursor; the composite solvent is obtained by mixing organic acid, inorganic acid and auxiliary agent, and the mass ratio of organic acid, inorganic acid and auxiliary agent is (2.5-6):(0.5-2):1; the organic acid is at least one of tartaric acid, oxalic acid and malic acid, the inorganic acid is at least one of phosphoric acid, nitric acid and sulfuric acid, and the auxiliary agent is citric acid; In step (4), the amount of nitric acid solution added is based on nitric acid and is 2.5%-5% of the mass of the hydrocracking catalyst; the amount of alumina added is 25%-35% of the mass of the hydrocracking catalyst; and the amount of metal composite modified molecular sieve oxide added is 55%-65% of the mass of the hydrocracking catalyst.

2. The preparation method according to claim 1, characterized in that, The base liquid is at least one of deionized water, ethanol, propanol, and isopropanol.

3. The preparation method according to claim 1, characterized in that, In step (2), the tungsten salt is calculated as tungsten oxide, and the amount of tungsten oxide added accounts for 15 to 35 wt% of the mass of the modified molecular sieve oxide material; The nickel salt is calculated as nickel oxide, and the amount of nickel oxide added accounts for 5 to 10 wt% of the mass of the modified molecular sieve oxide material. The tungsten salt and nickel salt are dissolved in water at a temperature of 75–95°C, and phosphoric acid is also added; the amount of phosphoric acid added accounts for 2–5 wt% of the mass of the modified molecular sieve oxide material. The complexing agent is at least one of ethylenediaminetetraacetic acid, citric acid, and sodium ethylenediaminetetramethylene phosphate; the amount of the complexing agent added is 5 to 30 wt% of the mass of the modified molecular sieve oxide material.

4. The preparation method according to claim 1, characterized in that, The third aging process takes place at a temperature of 20-85℃ and a stirring rate of 20-200 r / min.

5. The preparation method according to claim 1, characterized in that, The specific surface area of ​​the hydrocracking catalyst is 280–320 m². 2 / g, pore volume is 0.27~0.40mL / g, pore size is 7.8~10.2nm.

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