Process for the preparation of a bulk hydrocracking catalyst

Abstract

The application discloses a preparation method of a bulk phase hydrocracking catalyst, which comprises the following steps: (1) adding deionized water and phosphate into a reaction tank, continuously feeding CO2, and carrying out a gelation reaction of a W and Mo-containing solution and a sodium metaaluminate solution A to obtain material A; (2) adding a Ni-containing solution and an aqueous precipitant solution into the material A, carrying out a reaction, aging treatment, and adding a sodium metaaluminate solution B and a beta molecular sieve slurry in n times during the aging process to obtain a slurry, and then filtering the slurry to obtain material B; and (3) subjecting the material B obtained in the step (2) to first drying, rolling, molding, washing, second drying and calcination to obtain the bulk phase hydrocracking catalyst. The catalyst prepared by the application has excellent isomerization performance and aromatic hydrocarbon conversion capacity, and is suitable for application in a hydrogenation cracking process for producing special oil and lubricating oil base oil.

Description

Technical Field

[0001] This invention belongs to the field of petroleum refining technology, and specifically relates to a method for preparing a bulk hydrocracking catalyst. Background Technology

[0002] Hydrocracking diesel fractions are characterized by their water-white color, low impurity content, and high saturated hydrocarbon content. They can be blended to produce various white oils, rust-preventive oils, transformer oils, and aluminum cold-rolling oils. Hydrocracking tail oil fractions are suitable as lubricating oil base oils. Industrial white oils, depending on the grade, have pour points ranging from -3 to -9°C, with an aromatic hydrocarbon content not exceeding 5%. Transformer oils, depending on the minimum cold-state operating temperature in practical applications, have pour points ranging from -10°C to -50°C, with a polycyclic aromatic hydrocarbon content less than 3%. According to special oil product specifications, hydrocracking catalysts must simultaneously possess high isomerization performance and high aromatic hydrocarbon conversion capacity, requiring good synergistic effects between the acidic components and the hydrogenation active metal components in the catalyst.

[0003] Currently, the commonly used acidic components in hydrocracking are Y-zeolite, β-zeolite, and ZSM-5 zeolite. Among them, β-zeolite has the best isomerism and can meet the pour point requirements of industrial white oil. However, conventional supported hydrogenation catalysts and existing bulk catalysts are difficult to meet the requirements for polycyclic aromatic hydrocarbon content in industrial white oil.

[0004] Hydrocracking is carried out under high pressure, where hydrocarbon molecules undergo cracking and hydrogenation reactions on the catalyst surface to produce lighter molecules. Simultaneously, hydrodesulfurization, denitrogenation, and hydrogenation of unsaturated hydrocarbons also occur. Traditional supported hydrocracking catalysts are limited by the pore structure of the support, with active metal loading generally not exceeding 30 wt%. The hydrogenation activity of these catalysts is far from meeting the aromatic conversion activity required for producing high-value-added specialty oil products. While bulk hydrocracking catalysts prepared by co-precipitation have higher active metal content, the oxide particles generated during the co-precipitation reaction are of varying sizes, resulting in smaller pore volume and specific surface area, and lower active metal utilization. Furthermore, molecular sieves are mostly added after the active metal precipitation, failing to connect the channels of the previously formed oxide particles with the molecular sieve channels. This reduces the synergistic effect between acidic and hydrogenated components and the catalyst's diffusion performance, thus weakening the hydrocracking activity of the bulk catalyst. Therefore, bulk catalysts produced using existing technologies still cannot meet the hydrogenation activity requirements for producing high-value-added specialty oil products. Meanwhile, the nitrogen resistance of hydrocracking catalysts also affects their isomerization and aromatic conversion efficiency. Nitrogen-containing compounds in hydrocracking feedstocks have varying degrees of poisoning (shielding) effects on the acidic centers of hydrocracking catalysts. Hydrocracking catalysts with good nitrogen resistance can improve the feedstock adaptability of the catalysts and extend the operating cycle of industrial plants.

[0005] CN106179462A discloses a hydrocracking catalyst and its preparation method. The method first prepares a precipitate slurry I containing Ni and Al components using a direct addition method, then prepares a precipitate slurry II containing W, Si, and Al components using a co-current method. The two precipitate slurries are mixed uniformly, aged, and filtered. The resulting material is then mixed with urea and subjected to hydrothermal treatment with steam. Finally, a Y-type molecular sieve suspension is added. This method results in catalyst oxides of varying sizes. After hydrothermal treatment, excessive accumulation of surface active metals occurs, failing to improve the utilization rate of surface active metals. Furthermore, the addition of the molecular sieve significantly reduces the synergistic effect between the acidic and hydrogenation components of the catalyst.

[0006] CN103055923A discloses a method for preparing a hydrocracking catalyst. The method is as follows: An acidic mixed solution A containing a hydrocracking active metal and silicon is prepared; an alkaline solution B of sodium aluminate is prepared; then, the acidic mixed solution A, the alkaline solution B, and gaseous CO2 are added concurrently to a reaction vessel containing purified water to form a gel; a suspension of Y-type molecular sieve is added and mixed evenly; the mixture is then filtered, dried, shaped, washed, dried, and calcined to obtain the hydrocracking catalyst. This method can increase the pore volume and specific surface area of ​​the catalyst; however, the increase in pore volume and specific surface area and the improvement in the dispersion of the active catalyst metal are limited, relying solely on the carbonate generated during precipitation and the gas released during calcination. Furthermore, it easily leads to the aggregation of active metals in the catalyst.

[0007] CN110038617A discloses a hydrocracking catalyst and its preparation method. This hydrocracking catalyst is a bulk catalyst. The process involves first reacting a mixed solution A containing Ni, W, and Al components with a precipitant in a co-current flow to form a gel, followed by preliminary aging of the resulting slurry. Then, a mixed solution B containing W, Si, and Al components is added to the aged slurry in a co-current flow with the precipitant for further reaction. A suspension of molecular sieves is then added for further aging, followed by post-treatment to obtain the hydrocracking catalyst. However, the catalyst has a relatively small specific surface area and pore volume, and its hydrocracking activity does not meet the standards for industrial-grade white oil products.

[0008] CN106513006A discloses a method for preparing a bulk hydrogenation refining catalyst. The method includes: pre-dispersing a Ni-containing compound with deionized water under ultrasonic conditions; then adding a Mo-containing compound to form a Ni-Mo fine-grained structure; then adding a W-containing compound and a complexing agent for a hydrothermal reaction; finally, mixing and extruding the resulting active component powder with aluminum hydroxide dry adhesive; and finally drying and calcining to obtain the catalyst. The catalyst prepared by this method exhibits uniform dispersion among the different active phase grains, but the active metal in the bulk catalyst is not fully utilized, and the amount of surface-phase active metal is low, resulting in insufficient improvement in hydrogenation performance.

[0009] The hydrogenation activity of catalysts prepared by existing technologies is not yet sufficient for the production of industrial white oil. Therefore, improving the utilization rate of active metals in bulk catalysts and enhancing the synergistic effect between hydrogenation components and acidic components are key to meeting the requirements of bulk hydrocracking catalysts for the production of industrial white oil. Summary of the Invention

[0010] To address the shortcomings of existing technologies, this invention provides a method for preparing a bulk hydrocracking catalyst. The catalyst prepared by this method exhibits a stepped pore size distribution, a high density of surface active sites, small and uniformly distributed active metal oxide particles, good synergistic effects between the hydrocracking active component and the acidic component, and excellent nitrogen resistance. The catalyst prepared by this invention also possesses excellent isomerization properties and aromatic hydrocarbon conversion capabilities, making it suitable for application in hydrocracking processes for producing specialty oils and lubricating oil base oils.

[0011] The method for preparing the bulk hydrocracking catalyst of the present invention includes:

[0012] (1) Add deionized water and phosphate ester to the reaction vessel, continuously pass CO2 through, and add the solution containing W and Mo and sodium aluminate solution A in parallel stream to the reaction vessel to carry out the gelation reaction to obtain material A;

[0013] (2) Add the Ni-containing solution and the precipitant aqueous solution to the material A obtained in step (1) to react, and then age it. During the aging process, add sodium aluminate solution B and β molecular sieve slurry in n parts and filter the slurry to obtain material B. The method of adding sodium aluminate solution B and β molecular sieve slurry in n parts is as follows: each time, add 1 / n volume of sodium aluminate solution B first, and then add 1 / n volume of β molecular sieve slurry, and repeat this process n times, where n is an integer between 2 and 8.

[0014] (3) The material B obtained in step (2) is dried, rolled, shaped and washed, and then dried and calcined to obtain a bulk hydrocracking catalyst.

[0015] In the method of the present invention, the phosphate ester mentioned in step (1) is one or more of octadecyl ether phosphate (O-5P), alkylphenol ether phosphate (TXP-4, TXP-10), isomeric tridecyl ether phosphate (E-1310P), lauryl ether phosphate (MOA-3P, MOA-9P), castor oil phosphate, octadecyl phosphate, and lauryl phosphate, preferably one or more of alkylphenol ether phosphate (TXP-4, TXP-10), isomeric tridecyl ether phosphate (E-1310P), lauryl ether phosphate (MOA-3P, MOA-9P), and castor oil phosphate. The molar ratio of the phosphate ester to Al in the sodium aluminate solution in step (1) is 0.2:1 to 2.0:1, preferably 0.3:1 to 1.8:1.

[0016] In the method of the present invention, the concentration of CO2 gas added in step (1) is 40v% to 70v%; the flow rate of CO2 gas is 30 to 120 mL / min, and the CO2 gas is stopped after the gelation reaction is completed.

[0017] In the method of the present invention, in the W and Mo-containing solution in step (1), the weight concentration of W as WO3 is 5-120 g / L, preferably 10-110 g / L, and the weight concentration of Mo as MoO3 is 5-110 g / L, preferably 10-100 g / L; wherein, when preparing the W and Mo-containing solution, the tungsten source is generally ammonium metatungstate, and the molybdenum source is ammonium molybdate.

[0018] In the method of the present invention, the concentration of sodium aluminate solution A in step (1) is 5-90 g / L, preferably 8-80 g / L, based on the Al2O3 concentration.

[0019] In the method of the present invention, the conditions for the gelation reaction in step (1) are: the reaction temperature is 30-95℃, preferably 40-95℃, the pH value of the concurrent reaction is controlled at 5-6, and the reaction time is 0.1-1.0 hours.

[0020] In the method of the present invention, in the Ni-containing solution mentioned in step (2), the weight concentration of Ni, calculated as NiO, is 5 to 130 g / L, preferably 10 to 115 g / L; when preparing the Ni-containing solution, the nickel source is generally one or more of nickel sulfate, nickel nitrate, and nickel chloride; in the sodium aluminate solution B, the weight concentration of Al, calculated as Al2O3, is 5 to 70 g / L, preferably 8 to 60 g / L.

[0021] In the method of the present invention, in step (2), sodium aluminate solution B is preferably divided into n equal parts by volume, where n is an integer from 2 to 8; β molecular sieve slurry is preferably divided into n equal parts by volume, where n is an integer from 2 to 8.

[0022] In the method of the present invention, the precipitant in step (2) is an alkaline precipitant, selected from one or more of sodium carbonate, sodium bicarbonate, sodium hydroxide, potassium hydroxide, potassium carbonate or potassium bicarbonate, preferably ammonia and sodium hydroxide. The concentration of the precipitant aqueous solution is adjusted according to actual needs, such as the concentration of sodium hydroxide solution is 7wt% to 20wt%.

[0023] In the method of the present invention, the reaction conditions in step (2) are as follows: the reaction temperature is 30-95℃, preferably 40-95℃, the pH value is controlled at 8.0-12.0 at the end, and the reaction time is 0.5-2.5 hours; preferably, the reaction temperature in step (2) is the same as the reaction temperature in step (1).

[0024] In the method of the present invention, the aging treatment conditions in step (2) are: the aging temperature is 60-98℃, preferably 65-92℃. The aging process is carried out in the following manner: n three-stage decreasing pH aging is performed. In each three-stage decreasing pH aging, when adjusting the pH value in the first stage, 1 / n volume of sodium aluminate solution B is used for adjustment, and then 1 / n volume of β molecular sieve slurry is added; wherein the three-stage decreasing pH aging is: first stage, pH value is 11.0-13.5, aging time is 0.05-0.5 hours; second stage, pH value is adjusted to 8.5-10.5, aging time is 0.05-0.5 hours; third stage, pH value is adjusted to 4.5-6.2, aging time is 0.05-0.5 hours.

[0025] In the aging process, except for the use of sodium aluminate solution B in the first stage of pH adjustment, the acids and bases used for pH adjustment can be inorganic salts, inorganic acids and inorganic bases that do not contain aluminum. The inorganic acids can be hydrochloric acid and acetic acid, and the inorganic bases can be one or more of sodium carbonate, sodium bicarbonate and sodium hydroxide. The concentration and amount of acid and base solutions can be adjusted according to the actual preparation needs.

[0026] In the method of the present invention, in step (2), the Al added to the sodium aluminate solution B accounts for 5% to 55% of the total Al in the obtained catalyst, calculated as Al2O3, preferably 6% to 50%.

[0027] In the method of this invention, the β-molecular sieve described in step (2) has the following properties: a molar ratio of silicon oxide to aluminum oxide of 30–90; and a specific surface area of ​​430–780 m². 2 / g, preferably 400-700m 2 / g; pore volume is 0.30~0.90cm³ 3 / g, preferably 0.35~0.85cm 3 / g; the infrared acid content is 0.10-0.45 mmol / g, preferably 0.18-0.40 mmol / g; the β molecular sieve slurry is a homogeneous mixture of β molecular sieve and deionized water, with a solid-liquid mass ratio of 1:1.1-1:5.5, preferably 1:1.3-1:5.0.

[0028] In the method of this invention, the first drying, molding, and washing in step (3) can be carried out using conventional methods in the art. The first drying conditions are as follows: drying at 40-150°C for 1-48 hours, preferably at 50-120°C for 4-36 hours. During the molding process, conventional molding aids, such as adhesives, extrusion aids, etc., can be added as needed. The adhesive is one or more of hydrochloric acid, nitric acid, sulfuric acid, acetic acid, oxalic acid, etc., and the extrusion aid refers to substances that are beneficial to extrusion molding, such as guar gum powder, carbon black, graphite powder, citric acid, etc., and the amount of extrusion aid accounts for 1wt% to 10wt% of the total dry basis of the material. Washing is generally done with deionized water or a solution containing decomposable salts (such as ammonium acetate, ammonium chloride, ammonium nitrate, etc.) until neutral.

[0029] The second drying process described in step (3) is as follows:

[0030] a. First, dry the material at 60-100℃ for 1.0-8.5 hours, preferably at 70-90℃ for 2.0-8.0 hours;

[0031] b. Spray water evenly onto the material obtained in step a, with a water-to-drying-material volume ratio of 1:4 to 4:1, and then dry it at a temperature of 150 to 280°C, preferably 150 to 250°C, for a drying time of 0.5 to 4.0 hours, preferably 0.6 to 3.5 hours.

[0032] c. Repeat step b 2 to 9 times, preferably 3 to 8 times;

[0033] In the first instance, the volume ratio of water added to the volume of dried material is greater than 1:1, while in the last instance, the volume ratio is less than 1:1. Furthermore, the volume ratio of water added to the volume of dried material gradually decreases as the number of repetitions increases.

[0034] Furthermore, the total drying time for the second drying is preferably 5 to 40 hours, and more preferably 7 to 38 hours.

[0035] In the method of the present invention, the calcination conditions in step (3) are as follows: calcination at 350-650°C for 1-24 hours, preferably at 400-600°C for 2-12 hours.

[0036] This invention also provides a bulk hydrocracking catalyst, comprising a hydrocracking active metal component, amorphous alumina, and β-zeolite; the catalyst particles comprise an outer surface layer, an intermediate layer, and a central core, with the average pore diameter decreasing in a gradient, i.e., the average pore diameter of the outer surface layer is greater than that of the intermediate layer, and the average pore diameter of the intermediate layer is greater than that of the central core; the average pore diameter of the outer surface layer is 11–19 nm, the average pore diameter of the intermediate layer is 7–11 nm, and the average pore diameter of the central core is 3–7 nm, wherein the length from the outermost edge to the center point on the cross-section of the catalyst particle is R; the thickness of the outer surface layer is 0.2R–0.4R, the thickness of the intermediate layer is 0.2R–0.5R, and the remainder is the central core; the W / Mo molar ratio is 1:5–21:1, preferably 1:3–19:1, and the Ni / (Mo+W) molar ratio is 1:14–16:1, preferably 1:12–14:1. The ratio of the sum of the weight contents of the surface active metal components WO3 and NiO to the sum of the weight contents of the bulk active metal components WO3 and NiO is 2.8:1 to 6.5:1, preferably 3.4:1 to 6.2:1; the ratio of the sum of the weight contents of the surface active metal components MoO3 and NiO to the sum of the weight contents of the bulk active metal components MoO3 and NiO is 2.0:1 to 5.5:1, preferably 2.2:1 to 5.2:1. The catalyst of this invention is in the form of (solid) granules, with the average pore diameter decreasing from the outer surface layer to the central core.

[0037] In the catalyst of this invention, the average particle size of the active metal oxide particles of tungsten, molybdenum, and nickel is 10–14 nm. Preferably, the particle size distribution of the oxide particles is as follows: particles with a diameter less than 10 nm account for 2%–17% of the total number of particles, particles with a diameter of 10 nm–14 nm account for 72%–90% of the total number of particles, and particles with a diameter greater than 14 nm account for 3%–19% of the total number of particles.

[0038] The hydrocracking catalyst is in solid granular form and can be prepared using conventional molding methods. The shape can be any of the commonly used shapes for hydrocracking catalysts, such as cylindrical or spherical. Spherical shapes can be round or ellipsoidal, while cylindrical shapes can be cylindrical, square, or irregularly shaped (e.g., cloverleaf, four-leaf clover) cross-sections. The particle size of the catalyst is 1–10 mm. Generally, when cylindrical, the length can be 2–10 mm and the particle size can be 1–6 mm. When spherical, the particle size is generally 2–10 mm.

[0039] The hydrocracking catalyst of the present invention can be used in the hydrocracking process of base oils for the production of specialty oils and lubricating oils, and is particularly suitable for the hydrocracking process of base oil feedstocks for the production of transformer oil, white oil and high viscosity index lubricating oils.

[0040] The hydrocracking catalyst of this invention is applicable to a wide range of heavy feedstocks, including one or more of various hydrocarbon oils such as vacuum gas oil, coking gas oil, deasphalted oil, thermal cracking gas oil, catalytic cracking gas oil, and catalytic cracking cycle oil. These typically contain hydrocarbons with boiling points of 250–550°C and nitrogen content ranging from 300–2500 μg / g. After hydrocracking pretreatment, the nitrogen content in the feedstock of the hydrocracking catalyst of this invention is less than 150 μg / g, meaning the nitrogen content in the feedstock of the hydrocracking catalyst reaction section is less than 150 μg / g, further exceeding 10 μg / g, or even exceeding 50 μg / g. The hydrocracking catalyst of this invention maintains high activity, stability, and good product quality even under high nitrogen content feed conditions (less than 150 μg / g).

[0041] Compared with the prior art, the present invention has the following advantages:

[0042] 1. The method of this invention, through comprehensive control of the preparation steps and conditions, results in smaller and more uniformly distributed oxide particles that can fully contact the molecular sieve. Simultaneously, the increased pore volume and size of the catalyst surface phase enhance the likelihood of interconnection between the active component support channels and the molecular sieve channels, thereby improving the catalyst's diffusion performance and the synergistic effect between the hydrogenation component and the acidic component. The catalyst surface phase possesses higher hydrogenation active sites and a stepped pore distribution, enabling more and faster hydrogenation of organic nitrogen-containing compounds that are highly poisonous to the catalyst's acidic centers. This protects the acidic centers of the catalyst, improves the nitrogen resistance of the hydrocracking catalyst, and also enhances the properties of the hydrocracking products.

[0043] 2. In the gelation process of step (1) of the method of the present invention, when CO2 gas is introduced, the gas concentration and flow rate are controlled to obtain ideal reaction liquid microbubbles. The microbubbles are small in volume, suspended in water, and constantly undergo irregular collisions. Under the combined effect of phosphate ester and reaction liquid microbubbles, the particle size of metal oxides in the catalyst is small, which helps to improve the dispersion of active metals, reduce the probability of micropore formation, and increase the pore volume and specific surface area of ​​the bulk catalyst.

[0044] 3. In step (2) of this invention, a Ni-containing solution is added dropwise to the well-dispersed, small-particle-size W, Mo, and Al precipitate slurry prepared in step (1). This specific addition order, corresponding pH control, and active metal precipitation order optimize the pore size distribution and active metal dispersion of the obtained catalyst, significantly increasing the active metal content in the surface phase. This is beneficial for improving the hydrogenation saturation activity of the W-Ni combination and the hydrogenation denitrification activity of the Mo-Ni combination. With the increase of surface phase metal content, the synergistic effect of the acidic component and the hydrogenation component is further enhanced.

[0045] 4. In this invention, the pH value is oscillated during aging and sodium aluminate solution is added in stages. The pH value oscillation dissolves the amorphous oxide in the oxide particles, and the addition of sodium aluminate solution modifies the size of the oxide particles. With each addition of molecular sieve, the metal oxide particles are in better contact with the molecular sieve, which promotes the synergistic effect of the acidic component and the hydrogenated component.

[0046] 5. In the second drying process after the catalyst is formed, the average pore diameter of the catalyst particles decreases from the outer surface layer to the central core, presenting a stepped pore size distribution. This can reduce the diffusion effect when large molecules and other reactants with larger molecular diameters enter and exit the catalyst pores, which is beneficial to improving the diffusion performance of the catalyst for large molecules and is more conducive to the hydrogenation of large molecules and other reactants by the active metals such as tungsten, nickel and molybdenum on the catalyst surface.

[0047] The hydrocracking catalyst prepared by the method of this invention exhibits high aromatic saturation reaction performance. The catalyst combines high isomerization performance and high aromatic conversion capacity. When used in the hydrocracking process for producing specialty oils, the aromatic content and pour point of the hydrocracking diesel fraction meet the requirements of industrial-grade specialty oil base oil standards. It achieves these standards without further deep processing, reducing operating costs, increasing product added value, and creating greater economic benefits. The hydrocracking catalyst of this invention maintains good stability and product quality even under high nitrogen feed conditions. Detailed Implementation

[0048] In this invention, the specific surface area and pore volume are determined by the cryogenic liquid nitrogen adsorption method, and the mechanical strength is determined by the lateral pressure method.

[0049] In this invention, the content of active metals on the surface of the catalyst is determined by X-ray photoelectron spectroscopy (XPS), and the content of active metals in the bulk of the catalyst is determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES).

[0050] In this invention, wt% is the mass fraction and v% is the volume fraction.

[0051] In this invention, the average particle size (D50 particle size) and particle size distribution of the active metal oxide particles were measured using a nanoparticle size and Zeta potential analyzer (Zetasizer Nano ZS).

[0052] In this invention, "cross-section of a catalyst particle" refers to the entire surface exposed after cutting along the direction of the smallest dimension of a catalyst particle through its geometric center. For example, when the catalyst particle is spherical, the cross-section refers to the entire surface exposed after cutting along the radius or minor axis of the sphere through its center. Alternatively, when the catalyst particle is columnar, the cross-section refers to the entire surface exposed after cutting perpendicular to the length dimension of the column through its center point. The outer perimeter of the exposed surface is referred to as the outermost edge of the cross-section, and the geometric center (such as the aforementioned center of the sphere or the center point of the length dimension) is referred to as the center point of the cross-section.

[0053] In this invention, the method for determining the average pore diameter of different layers from the outer surface layer to the central core of catalyst particles is as follows: First, the pore volume, specific surface area, and average pore diameter of the sample are determined using the low-temperature nitrogen adsorption method (BET). Then, a certain amount of sample is placed in a catalyst abrasion apparatus and the sample is abraded, with a certain amount of quartz sand added to increase the abrasion rate. When the particle size of the sample is reduced to a certain extent after abrasion, the weight loss of the sample is measured, and its pore structure is measured again. Based on the relationship that the total pore volume and specific surface area of ​​the sample are equal to the sum of its individual parts, the pore volume and specific surface area of ​​the abraded portion can be calculated. Simultaneously, 20-80 samples are measured, and the average pore diameter is calculated. Thus, the average pore diameter of different layers from the outer surface layer to the central core is determined.

[0054] The properties of the β-zeolite used in this invention are shown in Table 7, and the properties of the Y-zeolite are shown in Table 8.

[0055] Example 1

[0056] Ammonium metatungstate and ammonium molybdate were added to dissolving tank 1 containing deionized water to prepare solutions containing W and Mo, with W (WO3) at a weight concentration of 68 g / L and Mo (MoO3) at a weight concentration of 32 g / L. Nickel chloride was added to dissolving tank 2 containing deionized water to prepare a Ni-containing solution, with Ni (NiO) at a weight concentration of 52 g / L. The sodium aluminate solution B contained 30% Al (Al2O3) of the total Al in the obtained hydrocracking catalyst, and was divided into 5 equal portions by volume. A β-molecular sieve slurry was prepared with a solid-liquid ratio of 1:3, and was also divided into 5 equal portions by volume. Deionized water and isomeric tridecyl ether phosphate (E-1310P) with a molar ratio of 0.9 to the total number of Al atoms in sodium aluminate solution A were added to the reaction vessel. CO2 gas with a concentration of 52% was introduced into the reaction vessel solution at a flow rate of 80 ml / min. A solution containing W and Mo and sodium aluminate solution A (Al concentration of 8.4 g / L, calculated as Al2O3) were added concurrently to a reaction vessel for a gelation reaction. The reaction pH was controlled at 5.4, and the reaction temperature was 62°C. After 0.8 hours of reaction, a Ni-containing solution and a sodium hydroxide solution (10% by weight) were simultaneously added dropwise to the reaction slurry. The reaction temperature remained unchanged, and the reaction time was 1.0 hour. At the end of the reaction, the pH was controlled at 8.8. After the reaction was completed, the CO2 gas was stopped, and a precipitate slurry containing nickel, molybdenum, tungsten, aluminum, and phosphorus was generated. The resulting slurry was aged at 78°C. During aging, one part of sodium aluminate solution B was added first to control the pH at 13.1. Then, one part of β-molecular sieve slurry was added. After aging for 0.2 hours, the pH was controlled at 9.6 and the aging time was 0.2 hours. Then, the pH was controlled at 5.5 and the aging time was 0.15 hours. The above operation process was repeated 5 times to complete the aging process. The obtained slurry was filtered, and the filter cake was dried for the first time at 100°C for 9 hours. It was then rolled and extruded into strips. The strips were washed with deionized water at room temperature until neutral. The washed wet strips are then dried as follows: First, the material is dried at 78℃ for 7.5 hours. Then, deionized water is evenly sprayed onto the dried material, and the drying process is repeated 5 times. The volume ratio of deionized water to dried material is 2.0:1 for the first spray, the drying temperature is 190℃, and the drying time is 2.0 hours. The volume ratio of deionized water to dried material is 1.5:1 for the second spray, the drying temperature is 190℃, and the drying time is 2.2 hours. The volume ratio of deionized water to dried material is 1:1 for the third spray, the drying temperature is 180℃, and the drying time is 1.8 hours. The volume ratio of deionized water to dried material is 1:1.8 for the fourth spray, the drying temperature is 180℃, and the drying time is 1.8 hours. The volume ratio of deionized water to dried material is 1:2.3 for the fifth spray, the drying temperature is 200℃, and the drying time is 1.9 hours.The dried material was calcined at 540℃ for 4 hours to obtain catalyst A. The composition and main properties of the catalyst are shown in Table 1.

[0057] Example 2

[0058] Ammonium metatungstate and ammonium molybdate were added to dissolving tank 1 containing deionized water to prepare a mixed W and Mo solution. The W concentration (as WO3) in the W and Mo solution was 52 g / L, and the Mo concentration (as MoO3) was 24 g / L. Nickel chloride was added to dissolving tank 2 containing deionized water to prepare a Ni solution. The Ni concentration (as NiO) in the Ni solution was 72 g / L. The Al in sodium aluminate solution B accounted for 35% of the Al (as Al2O3) in the obtained hydrocracking catalyst. The solution was divided into 6 equal parts by volume, and a β-molecular sieve slurry was prepared with a solid-liquid ratio of 1:3.2. The slurry was also divided into 6 equal parts by volume. Deionized water and castor oil phosphate with a molar ratio of 0.9 to the total number of Al atoms in sodium aluminate solution A were added to the reaction vessel. CO2 gas with a concentration of 57 vol% was introduced into the reaction vessel solution at a flow rate of 70 ml / min. A solution containing W and Mo and sodium aluminate solution A (Al concentration of 10.5 g / L, calculated as Al2O3) were added concurrently to a reaction vessel for a gelation reaction. The reaction pH was controlled at 5.2, and the reaction temperature was 55°C. After 0.8 hours of reaction, a Ni-containing solution and a sodium hydroxide solution (12% by weight) were simultaneously added dropwise to the reaction slurry. The reaction temperature remained unchanged, and the reaction time was 1.3 hours. At the end of the reaction, the pH was controlled at 9.5. After the reaction was completed, the CO2 gas was stopped, and a precipitate slurry containing nickel, molybdenum, tungsten, aluminum, and phosphorus was generated. The resulting slurry was aged at 80°C. During aging, an equal part of sodium aluminate solution B was added first to control the pH at 13.0. Then, an equal part of β-molecular sieve slurry was added. After aging for 0.15 hours, the pH was controlled at 10.1 and the aging time was 0.15 hours. Then, the pH was controlled at 4.8 and the aging time was 0.2 hours. The above operation process was repeated 6 times to complete the aging process. The aged slurry was filtered, and the filter cake was dried for the first time at 90°C for 8 hours. It was then rolled and extruded into strips. The strips were washed with deionized water at room temperature until neutral.The washed wet strips are then subjected to a second drying process as follows: First, the material is dried at 80℃ for 7.2 hours. Then, deionized water is evenly sprayed onto the dried material, and the process is repeated six times. The first spraying of deionized water to the dried material has a volume ratio of 2.2:1, a drying temperature of 210℃, and a drying time of 2.2 hours. The second spraying of deionized water to the dried material has a volume ratio of 1.5:1, a drying temperature of 200℃, and a drying time of 2.0 hours. The third spraying of deionized water to the dried material... The volume ratio of deionized water to dried material was 1:1.0, the drying temperature was 180℃, and the drying time was 1.8 hours. The fourth spraying involved a deionized water volume ratio of 1:1.5, a drying temperature of 190℃, and a drying time of 1.8 hours. The fifth spraying involved a deionized water volume ratio of 1:1.9, a drying temperature of 170℃, and a drying time of 1.7 hours. The sixth spraying involved a deionized water volume ratio of 1:2.3, a drying temperature of 180℃, and a drying time of 1.8 hours. The dried material was then calcined at 530℃ for 5 hours to obtain catalyst B. The catalyst composition and main properties are shown in Table 1.

[0059] Example 3

[0060] Ammonium metatungstate and ammonium molybdate were added to dissolving tank 1 containing deionized water to prepare solutions containing W and Mo, with W (as WO3) having a weight concentration of 60 g / L and Mo (as MoO3) having a weight concentration of 28 g / L. Nickel chloride was added to dissolving tank 2 containing deionized water to prepare a mixed Ni solution, with Ni (as NiO) having a weight concentration of 60 g / L. The Al in sodium aluminate solution B accounted for 38% of the Al (as Al2O3) in the obtained hydrocracking catalyst. The solution was divided into 5 equal parts by volume, and a β-molecular sieve slurry was prepared with a solid-liquid ratio of 1:2.8. The slurry was then divided into 5 equal parts by volume. Deionized water and lauryl ether phosphate (MOA-9P) with a molar ratio of 1.2 to the total number of Al atoms in sodium aluminate A were added to the reaction vessel. CO2 gas with a concentration of 56% was then introduced into the solution in the reaction vessel at a flow rate of 75 ml / min. A solution containing W and Mo and sodium aluminate solution A (Al concentration of 10 g / L, calculated as Al2O3) were added concurrently to a reaction vessel for a gelation reaction. The reaction pH was controlled at 5.9, and the reaction temperature was 65°C. After 0.9 hours of reaction, a Ni-containing solution and ammonia (11% by weight) were added dropwise to the reaction slurry. The reaction temperature remained constant, and the reaction time was 1.5 hours. At the end of the reaction, the pH was controlled at 10.5. After the reaction was completed, the CO2 gas was stopped, and a precipitate slurry containing nickel, molybdenum, tungsten, aluminum, and phosphorus was generated. The resulting slurry was aged at 80°C. During aging, an equal part of sodium aluminate solution B was added first to control the pH at 12.6. Then, an equal part of β-molecular sieve slurry was added. After aging for 0.2 hours, the pH was controlled at 9.6, and the aging time was 0.15 hours. Then, the pH was controlled at 5.0, and the aging time was 0.15 hours. The above operation process was repeated 5 times to complete the aging process. The aged slurry was filtered, and the filter cake was dried for the first time at 100℃ for 9 hours, then rolled and extruded into strips. It was washed with deionized water at room temperature until neutral.The washed wet strips are then subjected to a second drying process as follows: First, the material is dried at 84℃ for 7.0 hours. Then, deionized water is evenly sprayed onto the dried material, and the process is repeated six times. The first time, the volume ratio of deionized water to the dried material is 2.0:1, the drying temperature is 200℃, and the drying time is 2.2 hours. The second time, the volume ratio of deionized water to the dried material is 1.5:1, the drying temperature is 180℃, and the drying time is 1.9 hours. The third... The first spraying involved a deionized water to dried material volume ratio of 1.1:1, a drying temperature of 180℃, and a drying time of 1.8 hours. The fourth spraying involved a deionized water to dried material volume ratio of 1:1.3, a drying temperature of 170℃, and a drying time of 1.7 hours. The fifth spraying involved a deionized water to dried material volume ratio of 1:1.8, a drying temperature of 180℃, and a drying time of 1.8 hours. The sixth spraying involved a deionized water to dried material volume ratio of 1:2.2, a drying temperature of 170℃, and a drying time of 2.1 hours. The dried material was then calcined at 510℃ for 6 hours to obtain catalyst C. The composition and main properties of the catalyst are shown in Table 1.

[0061] Example 4

[0062] Ammonium metatungstate and ammonium molybdate were added to dissolving tank 1 containing deionized water to prepare W and Mo solutions, respectively. The weight concentration of W as WO3 in the W and Mo solutions was 64 g / L, and the weight concentration of Mo as MoO3 was 40 g / L. Nickel chloride was added to dissolving tank 2 containing deionized water to prepare Ni solutions, with the weight concentration of Ni as NiO being 40 g / L. The Al content of sodium aluminate solution B accounted for 30% of the Al (calculated as Al2O3) in the obtained hydrocracking catalyst. The solution was divided into four equal parts by volume, and a β-molecular sieve slurry was prepared with a solid-liquid ratio of 1:4.0. The slurry was then divided into four equal parts by volume. Deionized water and isomeric tridecyl ether phosphate (E-1310P) with a molar ratio of 1.1 to the total number of Al atoms in sodium aluminate A were added to the reaction vessel. CO2 gas with a concentration of 55% was introduced into the solution in the reaction vessel at a flow rate of 90 ml / min. A solution containing W and Mo and sodium aluminate solution A (Al concentration of 12.6 g / L, calculated as Al2O3) were added concurrently to a reaction vessel for a gelation reaction. The reaction pH was controlled at 5.2, and the reaction temperature was 70°C. After 0.7 hours of reaction, a Ni-containing solution and ammonia (12% by weight) were added dropwise to the reaction slurry. The reaction temperature remained constant, and the reaction time was 1.6 hours. At the end of the reaction, the pH was controlled at 10.2. After the reaction was completed, the CO2 gas was stopped, and a precipitate slurry containing nickel, molybdenum, tungsten, aluminum, and phosphorus was generated. The resulting slurry was aged at 75°C. During aging, an equal part of sodium aluminate solution B was added first to control the pH at 12.8. Then, an equal part of β-molecular sieve slurry was added. After aging for 0.16 hours, the pH was controlled at 9.6, and the aging time was 0.2 hours. Then, the pH was controlled at 5.4, and the aging time was 0.20 hours. The above operation process was repeated 4 times to complete the aging process. The obtained slurry was filtered, and the filter cake was dried for the first time at 80°C for 12 hours. It was then rolled and extruded into strips. The strips were washed with deionized water at room temperature until neutral.The washed wet strips are then dried as follows: First, the material is dried at 75℃ for 7.0 hours. Then, deionized water is evenly sprayed onto the dried material, and the process is repeated 6 times. The first spraying ratio of deionized water to dried material is 2.3:1, the drying temperature is 220℃, and the drying time is 2.3 hours. The second spraying ratio is 1.8:1, the drying temperature is 180℃, and the drying time is 2.0 hours. The third spraying ratio of deionized water to dried material is... The volume ratio of deionized water to dried material was 1:1, the drying temperature was 180℃, and the drying time was 1.9 hours. The fourth spraying involved a deionized water volume ratio of 1:1.4, a drying temperature of 170℃, and a drying time of 1.8 hours. The fifth spraying involved a deionized water volume ratio of 1:1.8, a drying temperature of 180℃, and a drying time of 1.8 hours. The sixth spraying involved a deionized water volume ratio of 1:2.3, a drying temperature of 170℃, and a drying time of 1.8 hours. The dried material was then calcined at 530℃ for 5 hours to obtain catalyst D. The composition and main properties of the catalyst are shown in Table 1.

[0063] Comparative Example 1

[0064] Reference catalyst E was prepared according to the method disclosed in CN101239324A. The composition and active metal content were the same as in Example 1. The molecular sieve was β molecular sieve. The specific steps were as follows: (1) Nickel chloride, ammonium molybdate, and aluminum chloride solutions were added to a dissolving tank containing deionized water. The mass concentration of Ni (NiO) in the solution was 52 g / L, the mass concentration of Mo (MoO3) was 32 g / L, and the mass concentration of Al (Al2O3) was 22 g / L. 2000 mL of purified water was added to dilute the solution. (2) Ammonia water was added while stirring until the pH value reached 5.2. (3) Sodium tungstate solution was prepared, containing 68 g / L of WO3. Add the mixture under stirring; (4) Continue to add ammonia water until the pH value is 7.8; (5) The entire gelation process should be carried out at 62℃; (6) The mixture is aged at 78℃ for 4 hours; before aging, add the β molecular sieve used in this preparation method, the β molecular sieve accounts for 13% of the total weight of the catalyst, the properties are shown in Table 4, and the aging is completed; (7) Filter, dry in an oven at 100℃ for 9 hours, roll, and extrude into strips with a perforated plate with a diameter of 3 mm; wash with ammonium acetate solution at pH=8.8 at room temperature; then dry in an oven at 80℃ for 10 hours, calcine at 540℃ for 4 hours to obtain catalyst E, the composition and properties of the catalyst are shown in Table 1.

[0065] Comparative Example 2

[0066] According to the preparation method disclosed in CN106179462A, the catalyst reference agent F with the same composition as in Example 1 of this invention was prepared, and the acidic component was β-zeolite. The specific process is as follows:

[0067] Nickel chloride and aluminum chloride solutions were dissolved in deionized water to prepare mixed solution A, with a NiO weight concentration of 52 g / L and an Al2O3 weight concentration of 15.4 g / L. Ammonium metatungstate, ammonium molybdate, and aluminum chloride solutions were dissolved in deionized water to prepare mixed solution B, with a WO3 weight concentration of 68 g / L, a MoO3 weight concentration of 32 g / L, and an Al2O3 weight concentration of 6.6 g / L. 10% (by weight) ammonia solution was added to solution A with stirring. The gelation temperature was maintained at 6.2℃, the pH was controlled at 7.8 at the end, and the gelation time was controlled at 0.8 hours, resulting in a nickel- and aluminum-containing precipitate slurry I. Deionized water was added to the reaction vessel, along with 10% (by weight) ammonia and solution B, which were added concurrently. The gelation temperature was maintained at 62°C, the pH was controlled at 7.8 during the concurrent gelation reaction, and the gelation time was controlled at 1.0 hour, generating slurry II containing tungsten, molybdenum, and aluminum precipitates. The two precipitate-containing slurries were mixed and aged for 4.0 hours at 78°C, with the pH controlled at 7.6. The mixture was then filtered, and the filter cake was hydrothermally treated with urea-containing steam. The hydrothermal treatment conditions were: a molar ratio of urea to total active metal atoms of 7:1, a temperature of 250°C, a pressure of 4.0 MPa, and a treatment time of 3 hours. After treatment, the filter cake was pulped, and a β-molecular sieve suspension was added to the mixture slurry for thorough stirring. The mixture was then filtered, and the filter cake was dried at 100°C for 9 hours, rolled, and extruded into strips. The strips were washed with deionized water at room temperature until neutral. The washed wet strips were then dried at 80°C for 10.0 hours. The dried material was calcined at 540℃ for 4 hours to obtain catalyst F. The catalyst composition, pore distribution and main properties are shown in Table 1.

[0068] Comparative Example 3

[0069] The same reference agent G as in Example 1 was prepared, except that the acidic component was Y molecular sieve. The composition and main properties of the catalyst are shown in Table 1.

[0070] Comparative Example 4

[0071] According to the preparation method disclosed in CN106513006A, β-molecular sieves were added to the powder and mixed evenly to prepare a reference agent H with the catalyst composition of Example 1 of this invention. The specific process is as follows:

[0072] Basic nickel carbonate was uniformly mixed with 300 ml of deionized water and then added to a 1 L high-pressure ultrasonic reactor. The ultrasonic frequency was set to 60 kHz, and the mixture was heated to 80 °C. After holding the temperature for 1 hour, the ultrasonic frequency was reduced to 20 kHz, and the system temperature was increased to 120 °C. Ammonium molybdate and polyvinylpyrrolidone were added, and then 10 ml of 25 wt% ammonia solution was added dropwise to the system. After holding the temperature for 2 hours, the ultrasonic treatment was turned off, and stirring was started at 300 rpm. Ammonium metatungstate was added, and then citric acid was added until the pH of the system reached 4.2. After holding the temperature for 2 hours, the heating was turned off, and the slurry was collected after the system cooled to room temperature. The slurry was spray-dried, with the inlet and outlet temperatures controlled at approximately 200 °C and 100 °C, respectively. The resulting dried powder was calcined in a muffle furnace at 330 °C for 3 hours to obtain the active component powder. β-molecular sieves were added to the powder and mixed evenly. The active component powder, the β-molecular sieve mixture, and aluminum hydroxide dry glue accounting for 40% of the weight of the active component powder were mixed. Then, 10% dilute nitric acid aqueous solution was added for kneading and extrusion to obtain strips with a diameter of 1.5 mm. The strips were dried at 110 °C for 10 h and calcined in a muffle furnace at 400 °C for 5 h to obtain reference agent H. The catalyst composition and main properties are shown in Table 1.

[0073] Comparative Example 5

[0074] Similar to Example 1, reference agent I was prepared by adding all sodium aluminate B solution and β-molecular sieve slurry at once during the aging process of the precipitate slurry containing nickel, molybdenum, tungsten, and aluminum. The aging pH value was kept constant. The specific preparation process is as follows:

[0075] Ammonium metatungstate and ammonium molybdate were added to dissolving tank 1 containing deionized water to prepare solutions containing W and Mo. The weight concentration of W as WO3 in the W-Mo solution was 68 g / L, and the weight concentration of Mo as MoO3 was 32 g / L. Nickel chloride was added to dissolving tank 2 containing deionized water to prepare a Ni-containing solution. The weight concentration of Ni as NiO in the Ni-containing solution was 52 g / L. The Al in the sodium aluminate B solution accounted for 30% of the total Al (calculated as Al2O3) in the obtained hydrocracking catalyst. Deionized water and isomeric tridecyl ether phosphate (E-1310P) with a molar ratio of 0.9 to the total number of Al atoms in sodium aluminate solution A were added to the reaction vessel. CO2 gas with a concentration of 52 vol% was introduced into the reaction vessel solution at a flow rate of 80 ml / min. A solution containing W and Mo, and sodium aluminate solution A (Al concentration as Al2O3, weight concentration 8.4 g / L) were added concurrently to a reaction vessel for a gelation reaction. The reaction pH was controlled at 5.4, and the reaction temperature was 62℃. After 0.8 hours of reaction, a Ni-containing solution and a sodium hydroxide solution (weight concentration 10%) were simultaneously added dropwise to the reaction slurry. The reaction temperature remained constant, and the reaction time was 1.0 hour. At the end of the reaction, the pH was controlled at 8.8. After the reaction was completed, the CO2 gas was stopped, and a precipitate slurry containing nickel, molybdenum, tungsten, aluminum, and phosphorus was generated. The resulting slurry was aged. At the beginning of aging, all sodium aluminate solution B and β-molecular sieve slurry were added. The aging temperature was 78℃, and the pH was controlled at 8.5. After aging for 4.0 hours, the aging was stopped. The resulting slurry was filtered, and the filter cake was dried for the first time at 100℃ for 9 hours. It was then rolled and extruded into strips. The strips were washed with deionized water at room temperature until neutral. The washed wet strips were then dried as follows: First, the material was dried at 78℃ for 7.5 hours. Then, deionized water was evenly sprayed onto the dried material, and the process was repeated five times. The first spraying ratio of deionized water to dried material was 2.0:1, the drying temperature was 190℃, and the drying time was 2.0 hours. The second spraying ratio was 1.5:1, the drying temperature was 190℃, and the drying time was 2.2 hours. The third spraying ratio was 1:1, the drying temperature was 180℃, and the drying time was 1.8 hours. The fourth spraying ratio was 1:1.8, the drying temperature was 180℃, and the drying time was 1.8 hours. The fifth spraying ratio was 1:2.3, the drying temperature was 200℃, and the drying time was 1.9 hours. The dried material was then calcined at 540℃ for 4 hours to obtain catalyst I. The composition and main properties of the catalyst are shown in Table 1.

[0076] Comparative Example 6

[0077] Similar to Example 1, reference agent J was prepared. During the preparation process, the second drying of the molded article after washing adopted the first drying conditions (conventional drying conditions). The specific preparation process is as follows:

[0078] Ammonium metatungstate and ammonium molybdate were added to dissolving tank 1 containing deionized water to prepare solutions containing W and Mo, respectively. The weight concentration of W as WO3 in the W-Mo solution was 68 g / L, and the weight concentration of Mo as MoO3 was 32 g / L. Nickel chloride was added to dissolving tank 2 containing deionized water to prepare a Ni-containing solution, with a Ni weight concentration of 52 g / L as NiO. Aluminum chloride was added to dissolving tank 3 containing deionized water. The Al content in sodium aluminate solution B accounted for 30% of the total Al (calculated as Al2O3) in the obtained hydrocracking catalyst. The solution was divided into 5 equal parts by volume, and a β-molecular sieve slurry was prepared with a solid-liquid ratio of 1:3. The slurry was then divided into 5 equal parts by volume. Deionized water and isomeric tridecyl ether phosphate (E-1310P) with a molar ratio of 0.9 to the total number of Al atoms in sodium aluminate solution A were added to the reaction vessel. CO2 gas with a concentration of 52% was introduced into the reaction vessel solution at a flow rate of 80 ml / min. A solution containing W and Mo and sodium aluminate solution A (Al concentration of 8.4 g / L, calculated as Al2O3) were added concurrently to a reaction vessel for a gelation reaction. The reaction pH was controlled at 5.4, and the reaction temperature was 62℃. After 0.8 hours of reaction, a Ni-containing solution and a sodium hydroxide solution (10% by weight) were simultaneously added dropwise to the reaction slurry. The reaction temperature remained unchanged, and the reaction time was 1.0 hour. At the end of the reaction, the pH was controlled at 8.8. After the reaction was completed, the CO2 gas was stopped, and a precipitate slurry containing nickel, molybdenum, tungsten, aluminum, and phosphorus was generated. The resulting slurry was aged at 78℃. During aging, one part of sodium aluminate solution B was added first to control the pH at 13.1. Then, one part of β-molecular sieve slurry was added. After aging for 0.3 hours, the pH was controlled at 9.6, and the aging time was 0.2 hours. Then, the pH was controlled at 7.5, and the aging time was 0.3 hours. The above operation process was repeated 5 times to complete the aging process. The obtained slurry was filtered, and the filter cake was dried for the first time at 100℃ for 9 hours, then rolled and extruded into strips. The strips were washed with deionized water at room temperature until neutral. The washed wet strips were dried at 100℃ for 9 hours, and the dried material was calcined at 540℃ for 4 hours to obtain catalyst J. The composition and main properties of the catalyst are shown in Table 1.

[0079] Comparative Example 7

[0080] Similar to Example 1, reference agent L was prepared. During the preparation process, only deionized water was added to the reaction vessel, and castor oil phosphate was not added. Furthermore, carbon dioxide gas was not introduced during the reaction. The specific reaction process is as follows:

[0081] Ammonium metatungstate and ammonium molybdate were added to dissolving tank 1 containing deionized water to prepare solutions containing W and Mo. The weight concentration of W as WO3 in the W-Mo solution was 68 g / L, and the weight concentration of Mo as MoO3 was 32 g / L. Nickel chloride was added to dissolving tank 2 containing deionized water to prepare a Ni-containing solution. The weight concentration of Ni as NiO in the Ni-containing solution was 52 g / L. The Al in sodium aluminate solution B accounted for 30% of the total Al (calculated as Al2O3) in the obtained hydrocracking catalyst. The solution was divided into 5 equal parts by volume, and a β-molecular sieve slurry was prepared with a solid-liquid ratio of 1:3. The slurry was then divided into 5 equal parts by volume. Deionized water was added to the reaction vessel. A solution containing W and Mo, and sodium aluminate solution A (Al concentration as Al2O3, weight concentration 8.4 g / L) were added concurrently to the reaction vessel for a gelation reaction. The reaction pH was controlled at 5.4, and the reaction temperature was 62℃. After 0.8 hours of reaction, a Ni-containing solution and a sodium hydroxide solution (weight concentration 10%) were simultaneously added dropwise to the reaction slurry. The reaction temperature remained constant, and the reaction time was 1.0 hour. At the end of the reaction, the pH was controlled at 8.8, generating a precipitate slurry containing nickel, molybdenum, tungsten, and aluminum. The resulting slurry was aged at 78℃. During aging, one part of sodium aluminate solution B was added first to control the pH at 13.1, followed by one part of β-molecular sieve slurry. After aging for 0.3 hours, the pH was controlled at 9.6, and the aging time was 0.2 hours. Then, the pH was controlled at 7.5, and the aging time was 0.3 hours. This process was repeated 5 times to complete the aging process. The obtained slurry was filtered, and the filter cake was dried for the first time at 100°C for 9 hours. It was then rolled and extruded into strips. The strips were washed with deionized water at room temperature until neutral. The washed wet strips were then dried as follows: First, the material was dried at 78℃ for 7.5 hours. Then, deionized water was evenly sprayed onto the dried material, and the process was repeated five times. The first spraying ratio of deionized water to dried material was 2.0:1, the drying temperature was 190℃, and the drying time was 2.0 hours. The second spraying ratio was 1.5:1, the drying temperature was 190℃, and the drying time was 2.2 hours. The third spraying ratio was 1:1, the drying temperature was 180℃, and the drying time was 1.8 hours. The fourth spraying ratio was 1:1.8, the drying temperature was 180℃, and the drying time was 1.8 hours. The fifth spraying ratio was 1:2.3, the drying temperature was 200℃, and the drying time was 1.9 hours. The dried material was then calcined at 540℃ for 4 hours to obtain catalyst K. The composition and main properties of the catalyst are shown in Table 1.

[0082] Example 5

[0083] This embodiment is an experiment to evaluate the activity of the catalyst of the present invention, and compares it with comparative catalysts. Catalysts A, B, C, and D of the present invention and comparative catalysts E, F, G, H, I, J, and K were used in comparative evaluation experiments on a 200 mL small-scale hydrogenation apparatus. The evaluation conditions were: total reaction pressure 15.7 MPa, hydrogen-to-oil volume ratio 1200:1, and liquid hourly space velocity 1.6 h⁻¹. 1 The reaction temperatures were 375℃ and 385℃. The raw material used for evaluation was vacuum-pressed wax oil, and its main properties are shown in Table 4. The evaluation results are shown in Tables 5 and 6. As can be seen from Tables 1-3, the catalyst of this invention has a smaller average particle size and uniform distribution of oxide particles, more surface active metals, larger surface pore size, and good synergistic effect between acidic and hydrogenated components. The evaluation process conditions and results show that, compared with the comparative catalyst, the catalyst of this invention has a smaller and more uniform distribution of active metals, pore size, and average oxide particle size, all of which are beneficial to improving aromatic saturation performance. In the hydrocracking process of heavy feedstock oil, the catalyst of this invention exhibits both high isomerization performance and high aromatic saturation performance. The pour point and aromatic content of the diesel fraction meet the standards for industrial-grade white oil and transformer oil, allowing for flexible production of transformer oil, white oil, and other specialty oils, as well as high viscosity index lubricating oil base oil feedstocks. The comparative catalyst cannot simultaneously possess both high isomerization performance and high aromatic saturation performance. The hydrocracking catalyst of this invention maintains good stability and good product quality even under high nitrogen content feed conditions.

[0084] Table 1. Composition and properties of catalysts prepared in the examples and comparative examples.

[0085]

[0086]

[0087] Continued in Table 1: Composition and properties of catalysts prepared in the examples and comparative examples.

[0088]

[0089] Table 2. Ratio of the weight content of surface active metal oxides to the weight content of bulk active metal oxides in the catalyst.

[0090] Catalyst number A B C D E F <![CDATA[Surface I W+Ni / Bulk I W+Ni > 5.38 5.19 5.60 5.82 0.92 1.02 <![CDATA[Surface I Mo + Ni / Bulk I Mo + Ni > 4.38 4.28 4.57 4.69 1.03 0.99

[0091] Continued from Table 2

[0092] Catalyst number G H I J K <![CDATA[Surface I W+Ni / Bulk I W+Ni > 4.41 1.18 3.98 5.02 4.64 <![CDATA[Surface I Mo + Ni / Bulk I Mo + Ni > 3.68 0.90 2.78 4.12 3.81

[0093] Table 3 shows the average particle size and particle size distribution of the catalyst oxide particles obtained in each example.

[0094] Catalyst number A B C D E F Average particle size of oxide particles, nm 11.9 12.2 11.6 11.2 26.5 28.9 Oxide particle size distribution, % Particle size less than 10nm 8.89 8.28 9.05 9.21 2.36 2.03 Particle size 10nm-14nm 80.64 79.91 81.07 81.67 10.98 8.56 Particle size greater than 14nm 10.47 11.81 9.88 9.12 86.66 89.41

[0095] Table 3 continues with the average particle size and particle size distribution of the catalyst oxide particles obtained in each example.

[0096] Catalyst number G H I J K Average particle size of oxide particles, nm 12.0 22.3 18.5 12.3 25.3 Oxide particle size distribution, % Particle size less than 10nm 8.82 3.18 6.86 8.78 3.12 Particle size 10nm-14nm 80.55 11.61 47.89 79.54 34.69 Particle size greater than 14nm 10.63 85.21 45.25 11.68 61.19

[0097] Table 4 Main Properties of Crude Oil

[0098]

[0099]

[0100] Table 5 Evaluation results of the catalysts in the examples and comparative examples (after 250 hours of operation)

[0101] catalyst A B C D E F Reaction temperature, °C 375 375 375 375 375 375 Nitrogen content in feed, μg / g 118 102 135 109 118 118 82~132℃ heavy naphtha Fang Qian, wt% 58.4 58.7 58.0 58.1 61.0 61.2 Aviation kerosene at 132–282℃ Smoke point / mm 29.6 29.4 29.8 29.9 23.4 24.1 Aromatics, v% 1.6 1.7 1.4 1.2 10.2 9.8 282~370℃ diesel Pour point / ℃ -7 -7 -7 -8 -7 -7 Aromatics / wt% 2.3 2.6 2.1 2.0 13.5 12.7 >370℃ tail oil BMCI value 5.8 6.0 5.5 5.2 23.9 23.3 Viscosity Index 123 122 125 127 88 91

[0102] Table 5 shows the evaluation results of the catalysts in the examples and comparative examples (after 250 hours of operation).

[0103]

[0104]

[0105] Table 6 Evaluation results of the catalysts in the examples and comparative examples (operational hours 2000 hours)

[0106] catalyst A B E F I J Reaction temperature, °C 375 375 385 385 385 385 Nitrogen content in feed, μg / g 118 102 118 118 118 118 82~132℃ heavy naphtha Fang Qian, wt% 58.6 58.9 62.2 62.4 62.0 62.6 Aviation kerosene at 132–282℃ Smoke point / mm 29.5 29.3 21.8 21.4 22.6 21.0 Aromatics, v% 1.8 2.0 19.1 19.9 18.0 20.9 282~370℃ diesel Pour point / ℃ -7 -7 -7 -8 -8 -9 Aromatics / wt% 2.5 2.8 18.0 19.2 17.6 20.6 >370℃ tail oil BMCI value 5.9 6.1 31.5 32.9 30.4 34.6 Viscosity Index 122 121 80 79 82 77

[0107] Table 7 Properties of β-zeolites in Examples and Comparative Examples

[0108] Silicon-aluminum molar ratio 80.5 <![CDATA[Specific surface area, m 2 / g]]> 621 Pore ​​volume, mL / g 0.55 Total acidity (infrared), mmol / g 0.43 <![CDATA[Na2O,wt%]]> 0.080

[0109] Table 8 Properties of the Y-type molecular sieve used in this invention

[0110] Molecular sieve properties Y Relative crystallinity, % 110 Unit cell parameters, nm 2.431 <![CDATA[SiO2 / Al2O3 molar ratio]]> 80.8 <![CDATA[Specific surface area, m 2 / g]]> 896 Pore ​​volume, mL / g 0.510 Total acidity (infrared), mmol / g 0.248 B acid / L acid 11.64 <![CDATA[Na2O,wt%]]> <0.01

Claims

1. A method for preparing a bulk hydrocracking catalyst, characterized in that... The following contents are included: (1) Add deionized water and phosphate ester to the reaction tank, continuously pass CO2, and add W and Mo-containing solutions and sodium aluminate solution A in parallel to the reaction tank for gelation reaction to obtain material A; (2) Add Ni-containing solutions and precipitant aqueous solutions to material A obtained in step (1) for reaction, then age treatment, and filter the slurry obtained by adding sodium aluminate solution B and β molecular sieve slurry n times during the aging process to obtain material B; the method of adding sodium aluminate solution B and β molecular sieve slurry n times is as follows: each time add 1 / n volume of sodium aluminate solution B first, then add 1 / n volume of β molecular sieve slurry, and do this n times in total, where n is an integer between 2 and 8; (3) The material B obtained in step (2) is dried, rolled, shaped and washed, and then dried and calcined to obtain a bulk hydrocracking catalyst. The second drying process in step (3) is as follows: a) the material is dried at 60~100℃ for 1.0~8.5 hours; b) water is sprayed evenly on the material obtained in step a, the volume ratio of water to dried material is 1:4~4:1, and then dried at 150~280℃ for 0.5~4.0 hours; c) the process of step b is repeated 2~9 times. The volume ratio of water added in the first time to dried material is greater than 1:1, and the volume ratio of water added in the last time to dried material is less than 1:

1.

2. The method according to claim 1, characterized in that: The phosphate ester mentioned in step (1) is one or more of octadecyl ether phosphate, alkylphenol ether phosphate, isotridecyl ether phosphate, lauryl ether phosphate, castor oil phosphate, octadecyl phosphate, and lauryl phosphate; the molar ratio of the phosphate ester to Al in the sodium aluminate solution in step (1) is 0.2:1 to 2.0:

1.

3. The method according to claim 1, characterized in that: In step (1), the concentration of CO2 gas introduced is 40v% to 70v%; the flow rate of CO2 gas is 30 to 120 mL / min, and the introduction of CO2 gas is stopped after the gelation reaction is completed.

4. The method according to claim 1, characterized in that: In step (1), the W and Mo-containing solution has a W concentration of 5-120 g / L (as WO3) and a Mo concentration of 5-110 g / L (as MoO3); the sodium aluminate solution A has a concentration of 5-90 g / L (as Al2O3).

5. The method according to claim 1, characterized in that: The conditions for the gelation reaction in step (1) are: reaction temperature of 30-95℃, pH value of concurrent reaction controlled at 5-6, and reaction time of 0.1-1.0 hours.

6. The method according to claim 1, characterized in that: In step (2), the Ni-containing solution has a Ni concentration of 5-130 g / L (calculated as NiO); and the sodium aluminate solution B has an Al concentration of 5-70 g / L (calculated as Al2O3).

7. The method according to claim 1, characterized in that: The precipitants mentioned in step (2) are all alkaline precipitants, selected from one or more of sodium carbonate, sodium bicarbonate, sodium hydroxide, potassium hydroxide, potassium carbonate, or potassium bicarbonate.

8. The method according to claim 1, characterized in that: The reaction conditions described in step (2) are as follows: the reaction temperature is 30 to 95°C, the pH value is controlled at 8.0 to 12.0 at the end, and the reaction time is 0.5 to 2.5 hours.

9. The method according to claim 1, characterized in that: The aging conditions described in step (2) are: aging temperature is 60-98℃; the aging process is carried out in the following manner: n times of three-stage decreasing pH aging, each time the pH value is decreased, when adjusting the pH value in the first stage, 1 / n volume of sodium aluminate solution B is used for adjustment, and then 1 / n volume of β molecular sieve slurry is added after adjustment. The three-stage decreasing pH aging process is as follows: Stage 1, pH value 11.0~13.5, aging time 0.05~0.5 hours; Stage 2, pH value adjusted to 8.5~10.5, aging time 0.05~0.5 hours; Stage 3, pH value adjusted to 4.5~6.2, aging time 0.05~0.5 hours.

10. The method according to claim 1, characterized in that: In step (2), the Al added to sodium aluminate solution B accounts for 5% to 55% of the total Al in the obtained catalyst, calculated as Al2O3.

11. The method according to claim 1, characterized in that: The β-zeolite described in step (2) has the following properties: a silica to alumina molar ratio of 30 to 90; and a specific surface area of ​​430 to 780 m². 2 / g, pore volume 0.30~0.90cm³ 3 / g, the infrared acid content is 0.10~0.45mmol / g; the β molecular sieve slurry is a homogeneous mixture of β molecular sieve and deionized water, with a solid-liquid mass ratio of 1:1.1 to 1:5.

5.

12. The method according to claim 1, characterized in that: In step (3), the first drying conditions are as follows: drying at 40~150℃ for 1~48 hours; during the molding process, one or more of the following are added as needed: the adhesive solvent is one or more of hydrochloric acid, nitric acid, sulfuric acid, acetic acid, and oxalic acid; the following are one or more of the following: guar gum powder, carbon black, graphite powder, and citric acid; the amount of the extrusion aid is 1wt%~10wt% of the total dry basis of the material; washing is done with deionized water or a solution containing decomposable salts until neutral.

13. The method according to claim 1, characterized in that: The roasting conditions for step (3) are as follows: roast at 350~650℃ for 1~24 hours.

14. A hydrocracking catalyst prepared by the method according to any one of claims 1 to 13, characterized in that: This catalyst is a bulk hydrocracking catalyst, comprising a hydrocracking active metal component, amorphous alumina, and β-zeolite. The catalyst particles consist of an outer surface layer, a middle layer, and a central core, with the average pore diameter decreasing in a gradient manner; that is, the average pore diameter of the outer surface layer is greater than that of the middle layer, and the average pore diameter of the middle layer is greater than that of the central core. The average pore diameter of the outer surface layer is 11–19 nm, the average pore diameter of the middle layer is 7–11 nm, and the average pore diameter of the central core is 3–7 nm. The length R from the outermost edge to the center point on the cross-section of the catalyst particle is given. The thickness of the outer surface layer is 0.2R–0.4R, the thickness of the middle layer is 0.2R–0.5R, and the remainder is the central core. The W / Mo molar ratio is 1:5–21:1, and the Ni / The (Mo+W) molar ratio is 1:14~16:1; the ratio of the sum of the weight contents of the surface active metal components WO3 and NiO to the sum of the weight contents of the bulk active metal components WO3 and NiO is 2.8:1~6.5:1, and the ratio of the sum of the weight contents of the surface active metal components MoO3 and NiO to the sum of the weight contents of the bulk active metal components MoO3 and NiO is 2.0:1~5.5:1; the average particle size of the tungsten, molybdenum, and nickel active metal oxide particles is 10~14 nm; the particle size distribution of the oxide particles is as follows: particles with a diameter less than 10 nm account for 2%~17% of the total number of particles, particles with a diameter of 10 nm~14 nm account for 72%~90% of the total number of particles, and particles with a diameter greater than 14 nm account for 3%~19% of the total number of particles.

15. The application of a hydrocracking catalyst prepared by any one of claims 1 to 13 in a hydrocracking process for producing specialty oils and lubricating oil base oils.

Images