A preparation method of a bulk hydrocracking catalyst

Abstract

The present invention discloses a preparation method of a bulk-phase hydrocracking catalyst, comprising: (1) adding a solution containing W and Mo and a sodium aluminate solution into a reaction tank in parallel flow for gelation reaction, and adding an organic auxiliary agent P1 after the reaction; (2) dropping a solution containing Ni and a precipitant into the reaction slurry obtained in step (1), aging the obtained slurry, and adding a solution containing Al in 2 to 8 times during the aging process. After the aging is completed, an organic auxiliary agent P2 and a β-zeolite slurry are added, and the mixture is stirred evenly, and the obtained slurry is filtered; (3) the material obtained in step (2) is subjected to first drying, rolling, forming, washing, and then second drying and calcination to obtain a hydrocracking catalyst. The catalyst prepared by the present invention has excellent isomerization performance and aromatics conversion ability at the same time, and is suitable for being applied in the hydrocracking process for producing special oil and lubricating base oil.

Description

Technical Field

[0001] The present invention belongs to the technical field of petroleum refining, and particularly relates to a preparation method of a bulk hydrocracking catalyst. Background Art

[0002] The use of hydrogenation technology can significantly reduce the contents of impurities such as sulfur, nitrogen, and aromatics in special oils, which is incomparable to other technologies. The hydrocracked diesel fraction has the characteristics of water-white color, low impurity content, and high saturated hydrocarbon content, and can be blended to produce various white oils, rust-proof oils, transformer oils, aluminum cold rolling oils, etc. The hydrocracked tail oil fraction is suitable as a lubricating oil base stock. Compared with conventional hydrocracking products such as refined oils and chemical raw materials, the quality indicators of special oils are significantly different. The requirements for low-temperature fluidity and aromatic content of transformer oil and industrial white oil are very strict. For industrial white oil with different grades, the pour point index is -3~-9°C, and the aromatic mass content requirement is not more than 5%. According to the lowest cold-state commissioning temperature in actual applications, the pour point index range of transformer oil products is between -10°C and -50°C, and the content requirement of polycyclic aromatic hydrocarbons is less than 3%. According to the special oil product indicators, the hydrocracking catalyst needs to have high isomerization performance and at the same time, have high aromatic conversion ability. It is difficult for the existing hydrocracking catalyst systems to achieve both.

[0003] The cracking activity of the hydrocracking catalyst comes from the acidity of the carrier component, and nitrogen-containing compounds in the feed have varying degrees of poisoning (shielding) effects on the acidic centers of the hydrocracking catalyst. After the feed is pretreated by hydrocracking, the nitrogen content needs to be controlled below 10 μg / g to ensure that the activity of the hydrocracking catalyst can be fully exerted. Due to the large amount of impurities in the feed, the feed pretreated by hydrocracking often fails to meet the requirements of the hydrocracking catalyst for the nitrogen content in the feed, and the nitrogen content of the treated feed still cannot meet the requirements, which requires improving the nitrogen tolerance of the hydrocracking catalyst. The hydrocracking catalyst with good nitrogen tolerance can improve the feed adaptability of the catalyst and extend the operation cycle of the industrial unit.

[0004] The bulk catalyst is currently the most active hydrocracking catalyst. The bulk hydrocracking catalyst can get rid of the limitation of the metal content, can arbitrarily adjust the proportion of each active component in the catalyst, and improve the hydrocracking performance of the catalyst. The combination of active metal components in the hydrocracking catalyst has better activity than the single component. Among the combinations of metal components, the W-Ni combination has the best hydrogenation saturation activity, and the Mo-Ni combination has the best hydrodenitrogenation performance. At the same time, the hydrocracking catalyst needs to have a larger pore diameter to facilitate the smooth passage of large-molecule reactants through the catalyst pores, which is beneficial to the removal of large-molecule nitrogen compounds.

[0005] CN103055923A discloses a preparation method of a hydrocracking catalyst. The method is as follows: Prepare an acidic mixed solution A containing a hydrogenation active metal and silicon, prepare a sodium aluminate alkaline solution B, and then add the acidic mixed solution A, the alkaline solution B and gas CO 2 into a reaction tank filled with purified water in a co-current manner to form a gel, add a suspension of Y-type molecular sieve and mix evenly, filter, dry, shape, and then wash, dry and calcine to obtain the hydrocracking catalyst. This method can increase the pore volume and specific surface area of the catalyst. However, in this method, only the gas released during the calcination of the carbonate formed in the precipitation is relied on to increase the pore volume, specific surface area and improve the dispersion of the active catalyst metal, which is limited. At the same time, it is easy to cause the aggregation of the active metal in the catalyst.

[0006] CN106179462A discloses a hydrocracking catalyst and its preparation method. In this method, a precipitate slurry I containing Ni and Al components is first prepared by the forward addition method, and then a precipitate slurry II containing W, Si and Al components is prepared by the co-current method. The two precipitate slurries are mixed evenly, aged and filtered. Then, the obtained material is mixed with urea and subjected to hydrothermal treatment with water vapor, and then a suspension of Y-type molecular sieve is added. This method mixes two precipitates prepared by different methods, which can control the distribution of different hydrogenation active metals. Then, the filter cake of the precipitate mixture is precipitated by hydrothermal treatment to increase the pore volume and specific surface area of the catalyst. However, after changing the pore volume and specific surface area by the impact force of the gas, the pore distribution of the catalyst is uneven, and the surface active metal shows excessive accumulation, without improving the utilization rate of the surface active metal. At the same time, after adding the molecular sieve, the mutual cooperation between the acidic components and the hydrogenation components of the catalyst is greatly reduced.

[0007] CN110038617A discloses a hydrocracking catalyst and its preparation method. The hydrocracking catalyst is a bulk catalyst. First, a mixed solution A containing Ni, W and Al components is co-currently reacted with a precipitant to form a gel, and the obtained slurry is preliminarily aged. Then, a mixed solution B containing W, Si and Al components is co-currently added to the above-aged slurry for reaction, and then a suspension of molecular sieve is added for aging, and then the hydrocracking catalyst is prepared through post-treatment. The specific surface area and pore volume of the catalyst are small, and the hydrogenation activity cannot meet the standards of industrial white oil products.

[0008] CN106513006A discloses a preparation method of a bulk-phase hydrorefining catalyst. The method includes: mixing a Ni compound with deionized water for pre-dispersion under an ultrasonic environment, then adding a Mo compound to form a Ni-Mo fine grain structure, then adding a W compound and a complexing agent for hydrothermal reaction, and then kneading and extruding the obtained active component powder with aluminum hydroxide dry gel, followed by drying and calcination to obtain the catalyst. The catalyst prepared by the method of the present invention has uniform dispersion among different active phase grains, high utilization rate of active metals, excellent pore structure properties, and improves the removal efficiency of complex sulfur compounds in inferior diesel through a direct desulfurization pathway. However, the hydrogenation activity of the catalyst is relatively low, the active metals in the bulk-phase catalyst are not fully utilized, the amount of surface active metals is not much, and the removal efficiency of nitrogen in macromolecular nitrogen-containing compounds is limited.

[0009] The above method for preparing the catalyst optimizes the physical and chemical properties of the catalyst to improve the hydrogenation activity and isomerization performance of the catalyst. However, it does not fundamentally solve the problems such as the decrease in pore volume and specific surface area of the bulk-phase catalyst, poor dispersion of active metals, poor interaction between active metal components, poor cooperation between hydrogenation components and acidic components, and lack of coordination between the distribution of active metals and pore distribution. The nitrogen resistance of the catalyst is relatively poor. Summary of the Invention

[0010] Aiming at the deficiencies of the prior art, the present invention provides a preparation method of a bulk-phase hydrocracking catalyst. The catalyst prepared by this method has a stepped pore size distribution, a large density of surface active sites, good synergistic effects between active components and acidic components, and good nitrogen resistance. The catalyst prepared by the present invention also has excellent isomerization performance and aromatics conversion ability, and is suitable for application in the hydrocracking process for producing special oils and lubricating base oils.

[0011] The preparation method of the bulk-phase hydrocracking catalyst of the present invention includes:

[0012] (1) Adding a solution containing W and Mo and a sodium aluminate solution into a reaction tank in a parallel flow manner for gel-forming reaction, and adding an organic auxiliary agent P1 after the reaction;

[0013] (2) Adding a solution containing Ni and a precipitating agent to the reaction slurry obtained in step (1), aging the obtained slurry, and adding a solution containing Al in 2 to 8 times during the aging process. After the aging is completed, adding an organic auxiliary agent P2 and a β zeolite slurry, mixing evenly, and filtering the obtained slurry;

[0014] (3) The material obtained in step (2) is subjected to first drying, rolling, shaping, washing, and then second drying and calcination to obtain a bulk-phase hydrocracking catalyst; wherein the organic auxiliary agent P1 is a random polyether polyoxyethylene-polyoxypropylene copolymer; the organic auxiliary agent P2 is a polyoxyethylene type non-ionic surfactant.

[0015] In the method of the present invention, in the solution containing W and Mo in step (1), the weight concentration of W calculated as WO 3 is 5 to 120 g / L, preferably 10 to 110 g / L, and the weight concentration of Mo calculated as MoO 3 is 5 to 110 g / L, preferably 10 to 100 g / L; among them, when preparing the solution containing W and Mo, the tungsten source generally used is ammonium metatungstate, and the molybdenum source is ammonium molybdate.

[0016] In the method of the present invention, in the sodium aluminate solution in step (1), the concentration of Al 2 O 3 is 5 to 90 g / L, preferably 8 to 80 g / L in terms of concentration.

[0017] In the method of the present invention, the conditions for the gelation reaction in step (1) are: the reaction temperature is 30 to 95 °C, preferably 40 to 95 °C, the pH value of the co-current reaction is controlled at 5 to 6, and the reaction time is 0.1 to 1.0 hours.

[0018] In the method of the present invention, the random polyether polyoxyethylene-polyoxypropylene copolymer in step (1) is selected from at least one of isomeric tridecanol random polyether TPE-1000, propylene glycol random polyether PPE-1500, glycerol random polyether GPE-3000, butanol random polyether BPE-1000, butanol random polyether BPE-1500, butanol random polyether BPE-2500, lauric acid random polyether LPE-1200, dodecanol random polyether CPE-1500; the molar ratio of the organic auxiliary P1 to W in the solution of W and Mo is 0.2 to 1.8, preferably 0.3 to 1.5.

[0019] In the method of the present invention, in the solution containing Ni in step (2), the weight concentration of Ni calculated as NiO is 5 to 130 g / L, preferably 10 to 115 g / L; in the solution containing Al, the weight concentration of Al calculated as Al 2 O 3 is 5 to 70 g / L, preferably 8 to 60 g / L. When preparing the solution containing Ni, the nickel source is generally one or more of nickel sulfate, nickel nitrate, nickel chloride; when preparing the solution containing Al, the aluminum source is generally a soluble aluminum salt, such as one or more of aluminum nitrate, aluminum sulfate, aluminum chloride, etc.

[0020] In the method of the present invention, in step (2), it is preferred to divide the solution containing Al into n parts by volume (where n is an integer from 2 to 8), preferably equally by volume.

[0021] In the method of the present invention, the precipitants described in step (2) are all alkaline precipitants, selected from one or more of sodium carbonate, sodium bicarbonate, ammonia water, sodium hydroxide, potassium hydroxide, potassium carbonate or potassium bicarbonate, preferably ammonia water and sodium hydroxide solution, the concentration of ammonia water is 5wt% - 15wt%, and the concentration of sodium hydroxide solution is 7wt% - 20wt%.

[0022] In the method of the present invention, the reaction conditions of step (2) are: the reaction temperature is 30 - 95°C, preferably 40 - 95°C, the pH value at the end is controlled at 8.0 - 12.0, and the reaction time is 0.5 - 2.5 hours; preferably, the reaction temperature of step (2) is the same as the reaction temperature of step (1).

[0023] In the method of the present invention, in step (2), the slurry is continuously subjected to n times of three - stage decreasing pH aging, and 1 / n of the Al - containing solution is added each time at the end of the first - stage pH value aging;

[0024] The specific process of each three - stage decreasing pH value aging is as follows: the aging temperature of each stage is 60 - 98°C, preferably 65 - 92°C; in the first stage, the pH value is 11.0 - 13.5, and the aging time is 0.05 - 0.5 hours. After the aging ends, 1 / n of the Al - containing solution is added. In the second stage, the pH value is adjusted to 8.5 - 10.5, and the aging time is 0.05 - 0.5 hours. In the third stage, the pH value is adjusted to 5.5 - 8.3, and the aging time is 0.05 - 0.5 hours; and so on (that is, the pH value is re - controlled to 11.0 - 13.5, and the aging time is 0.05 - 0.5 hours, where n is an integer from 2 to 8).

[0025] Among them, the acids and bases used to adjust the pH value during the aging process can be inorganic salts, inorganic acids and inorganic bases without aluminum element. The inorganic acid can be hydrochloric acid and acetic acid, and the inorganic base can be one or more of sodium carbonate, sodium bicarbonate, ammonia water, and sodium hydroxide. The concentration and dosage of the 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 through the Al - containing solution accounts for 5% - 55% of the total Al in the obtained hydrofining catalyst calculated as Al 2 O 3 O, preferably 6% - 50%.

[0027] In the method of the present invention, the organic auxiliary agent P2 in step (2) is a polyoxyethylene non-ionic surfactant, and can be selected from one or more of fatty alcohol polyoxyethylene ethers (C16-18 alcohol polyoxyethylene ether, C12-14 alcohol polyoxyethylene ether, oleyl alcohol polyoxyethylene ether, isomeric decyl alcohol polyoxyethylene ether, octylphenol polyoxyethylene ether, castor oil polyoxyethylene ether), alkylphenol polyoxyethylene (4, 6, 7, 9, 10, 15) ethers, dodecylamine polyoxyethylene ether, etc. The molar ratio of the organic auxiliary agent P2 to Ni in the Ni-containing solution is 0.8:1 to 4.5:1, preferably 1.0:1 to 3.8:1.

[0028] In the method of the present invention, the β zeolite described in step (2) has the following properties: the molar ratio of silica to alumina is 30 to 90; the specific surface area is 430 to 780 m 2 / g, preferably 400 to 700 m 2 / g; the pore volume is 0.30 to 0.90 cm 3 / g, preferably 0.35 to 0.85 cm 3 / g; the infrared acid amount is 0.10 to 0.45 mmol / g, preferably 0.18 to 0.40 mmol / g.

[0029] In the method of the present invention, the first drying, shaping and washing in step (3) can be carried out by conventional methods in the art. The first drying conditions are as follows: drying at 40 to 150 °C for 1 to 48 hours, preferably drying at 50 to 120 °C for 4 to 36 hours. During the shaping process, conventional shaping aids can be added as needed, such as one or more of peptizing agents, extrusion aids, etc. The peptizing agent 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 for extrusion shaping, such as one or more of sesbania powder, carbon black, graphite powder, citric acid, etc. The dosage of the extrusion aid accounts for 1 wt% to 10 wt% of the total dry basis of the materials. Washing is generally carried out using deionized water or a solution containing decomposable salts (such as ammonium acetate, ammonium chloride, ammonium nitrate, etc.) until neutral.

[0030] The second drying process in step (3) is as follows:

[0031] a. First, dry the material at 60 to 100 °C for 1.0 to 8.5 hours, preferably dry at 70 to 90 °C for 2.0 to 8.0 hours;

[0032] b. Uniformly spray water (preferably deionized water) on the material obtained in step a, and the volume ratio of the added water to the volume of the dried material is 1:4 to 4:1, and then dry 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;

[0033] c. Repeat step b for 2 to 9 times, preferably 3 to 8 times.

[0034] Among them, the volume ratio of the first water addition to the volume of the dried material is greater than 1:1, and the volume ratio of the last water addition to the volume of the dried material is less than 1:1. Further, the volume ratio of water addition to the volume of the dried material decreases successively with the increase of the drying times.

[0035] Further, the total drying time for the second drying is preferably 5 to 40 hours, more preferably 7 to 38 hours.

[0036] In the method of the present invention, the calcination conditions in step (3) are as follows: calcine at 350 to 650 °C for 1 to 24 hours, preferably calcine at 400 to 600 °C for 2 to 12 hours.

[0037] The present invention also provides a hydrocracking catalyst which is a bulk hydrocracking catalyst. The hydrocracking catalyst includes a hydrogenation active metal component, amorphous alumina and β zeolite; the catalyst particles include an outer surface layer, an intermediate layer and a central core, and the average pore diameter decreases in a gradient, that is, the average pore diameter of the outer surface layer is greater than the average pore diameter of the intermediate layer, and the average pore diameter of the intermediate layer is greater than the average pore diameter of the central core; the average pore diameter of the outer surface layer is 11 to 19 nm, the average pore diameter of the intermediate layer is 7 to 11 nm, and the average pore diameter of the central core is 3 to 7 nm. Among them, in the cross-section of the catalyst particles, the length from the outermost edge to the center point is R; the thickness of the outer surface layer is 0.2R to 0.4R, the thickness of the intermediate layer is 0.2R to 0.5R, and the rest is the central core; the molar ratio of W / Mo is 1:5 to 23:1, preferably 1:3 to 20:1, and the molar ratio of Ni / (Mo + W) is 1:12 to 16:1, preferably 1:10 to 14:1. Among them, the sum of the weight contents of the surface active metal components WO 3 and NiO and the sum of the weight contents of the bulk active metal components WO 3 and NiO is 2.3:1 to 6.0:1, preferably 2.5:1 to 5.8:1. The sum of the weight contents of the surface active metal components MoO 3 and NiO and the sum of the weight contents of the bulk active metal components MoO 3 and NiO is 1.5:1 to 4.7:1, preferably 1.8:1 to 4.3:1. The catalyst of the present invention is (solid) granular, and from the outer surface layer to the central core of the catalyst, the average pore diameter decreases from large to small.

[0038] For the hydrocracking catalyst, based on the weight of the hydrocracking catalyst, the total content of Ni, W and Mo in terms of oxides is 71% to 93%, preferably 73% to 90%; the content of amorphous alumina is 2% to 21%, preferably 3% to 19%; the content of β zeolite is 5% to 23%, preferably 5% to 20%.

[0039] The properties of the hydrocracking catalyst are as follows: the specific surface area is 220 - 600 m 2 / g, and the pore volume is 0.35 - 1.00 mL / g.

[0040] The hydrocracking catalyst is in the form of (solid) particles and can be prepared by conventional shaping methods. The shape can be various shapes commonly used for hydrocracking catalysts, such as cylindrical, spherical, etc. The spherical shape can be spherical, ellipsoidal, etc., and the cylindrical shape can be cylindrical, square-columnar or columnar with a special cross-section (such as clover, four-leaf clover, etc.). The particle size of the catalyst is 1 - 10 mm. Generally, when it is cylindrical, the length can be 2 - 10 mm and the particle size can be 1 - 6 mm. Generally, when it is spherical, the particle size is 2 - 10 mm.

[0041] The hydrocracking catalyst of the present invention can be used in the hydrocracking process for producing special oils and base oils of lubricating oils, and is particularly suitable for the hydrocracking process of raw materials for producing transformer oils, white oils and base oils of high-viscosity index lubricating oils.

[0042] The heavy feedstock range applicable to the hydrocracking catalyst of the present invention is very wide, and they include one or more of various hydrocarbon oils such as vacuum gas oil, coker gas oil, deasphalted oil, thermal cracking gas oil, catalytic cracking gas oil, catalytic cracking recycle oil, etc. Usually, they contain hydrocarbons with a boiling point of 250 - 550 °C, and the nitrogen content can be 300 - 2500 μg / g. After the hydrocracking pretreatment process, the nitrogen content in the feed of the hydrocracking catalyst of the present invention is less than 150 μg / g, that is, the nitrogen content in the feed of the reaction section of the hydrocracking catalyst is less than 150 μg / g, further 10 μg / g or more, and even 50 μg / g or more. The hydrocracking catalyst of the present invention still has high activity, stability and good product quality under the condition of high nitrogen content feed (less than 150 μg / g).

[0043] Compared with the prior art, the present invention has the following advantages:

[0044] The method for preparing a hydrocracking catalyst of the present invention first precipitates a mixed solution A containing W, Mo, and Al components, and drops a solution B containing Ni into the obtained slurry at a specific pH value. This specific addition sequence and corresponding pH value control the distribution of active metals. Different precipitation sequences of active metals, the addition of organic auxiliary P1, and the addition of an Al-containing solution in portions during aging result in a significant increase in the distribution of hydrocracking active metals tungsten, nickel, and molybdenum in the surface phase and a more uniform dispersion, which is beneficial to increasing the density of surface active sites of the combined active metals tungsten and nickel, and molybdenum and nickel. At the same time, the addition of the Al-containing solution in portions can not only increase the active metals in the surface phase of the catalyst but also increase the macropores in the bulk catalyst, making it easier for large-molecule reactants to pass through the pores, further optimizing the pore size distribution and active metal dispersion of the obtained catalyst, and strengthening the promotion effect between active metals. When the second drying method is used for the formed catalyst, in the pore distribution of the catalyst particles, from the outer surface layer to the central core of the catalyst, the average pore diameter decreases from large to small, presenting a stepped pore size distribution. This can weaken the influence of the diffusion effect when large-molecule 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 hydrocracking of large-molecule reactants such as those with larger diameters by the active metals tungsten, nickel, and molybdenum in the surface phase of the catalyst. The addition of organic auxiliary P2 helps to promote the synergistic effect between the acidic component and the hydrocracking component. Through the comprehensive control of the preparation steps and conditions, the surface phase of the catalyst has a high hydrocracking active site and a stepped pore distribution, which can hydrogenate organic nitrogen compounds that have a large poisoning effect on the acidic centers of the catalyst more and faster, playing a role in protecting the acidic centers of the catalyst, improving the nitrogen tolerance of the hydrocracking catalyst, and also improving the properties of hydrocracking products.

[0045] The hydrocracking catalyst obtained by the preparation method of the present invention has high aromatics saturation reaction performance. The catalyst has both high isomerization performance and high aromatics conversion ability. When used in the process of hydrocracking to produce special oil, the aromatics content and pour point of the hydrocracking diesel fraction product can meet the requirements of the industrial-grade special oil base oil standard. It can reach the industrial-grade special oil base oil standard without further deep processing, reducing the operating cost and increasing the product added value, and can create greater economic benefits. The hydrocracking catalyst of the present invention still has good stability and good product quality under the condition of high nitrogen content feed. Detailed implementation mode

[0046] In the present invention, the specific surface area and pore volume are measured by the low-temperature liquid nitrogen adsorption method, and the mechanical strength is measured by the side pressure method.

[0047] In the present invention, the content of active metals in the surface phase of the catalyst is measured by X-ray photoelectron spectroscopy (XPS), and the content of active metals in the bulk phase of the catalyst is measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES).

[0048] In the present invention, wt% is the mass fraction and v% is the volume fraction.

[0049] In the present invention, the "cross-section of the catalyst particle" refers to the entire surface exposed after cutting through the geometric center of its shape along the direction of the minimum dimension of a catalyst particle. For example, when the catalyst particle is spherical, the cross-section refers to the entire surface exposed after cutting through the center of the sphere along the radius or minor axis of the sphere. Alternatively, when the catalyst particle is columnar, the cross-section refers to the entire surface exposed after cutting through the center point of the length dimension perpendicular to the length dimension of the column. The outer periphery of the exposed surface is referred to as the outermost edge of the cross-section, and the geometric center (such as the center of the sphere or the center point of the length dimension mentioned above) is referred to as the center point of the cross-section.

[0050] In the present invention, for the method of measuring the average pore diameter of different layers from the outer surface layer to the central core of the catalyst particle: First, measure the pore volume, specific surface area, and average pore diameter of the sample by the low-temperature nitrogen adsorption method (BET). Then, take a certain amount of the sample and place it in a catalyst attrition tester, and polish the sample while adding a certain amount of quartz sand to increase the wear rate. When the particle size of the sample decreases to a certain extent after polishing, measure the weight loss of the sample and measure its pore structure again. From the relationship that the total pore volume and specific surface area of the sample are equal to the sum of each part, the pore volume and specific surface area of the polished part can be calculated. At the same time, measure 20 - 80 samples, and then calculate the average pore diameter. Thus, the average pore diameters of different layers from the outer surface layer to the central core are measured.

[0051] In the present invention, the properties of the β-zeolite used are shown in Table 6, and the properties of the Y-zeolite are shown in Table 7.

[0052] Example 1

[0053] Ammonium metatungstate and ammonium molybdate were respectively added to the dissolution tank 1 filled with deionized water to prepare a solution containing W and Mo. The weight concentration of W in the solution containing W and Mo, calculated as WO 3 was 68 g / L, and the weight concentration of Mo, calculated as MoO 3 was 32 g / L. Nickel chloride was added to the dissolution tank 2 filled with deionized water to prepare a solution containing Ni. The weight concentration of Ni in the solution containing Ni, calculated as NiO, was 52 g / L. Aluminum chloride was added to the dissolution tank 3 filled with deionized water to prepare a solution containing Al. The Al in the solution containing Al accounted for 30% of the total Al (calculated as Al 2 O 3 in the obtained hydrocracking catalyst), and it was divided into 5 equal parts by volume. Deionized water was added to the reaction tank, and the solution containing W and Mo and the sodium aluminate solution (Al calculated as Al 2 O 3The calculated weight concentration is 15.4 g / L) and added to the reaction tank in a concurrent flow for gelation reaction. The reaction pH value is controlled at 5.3, the reaction temperature is 62 °C. After reacting for 0.8 hours, isomeric tridecyl alcohol random polyether TPE-1000 is added to the reaction tank. The molar ratio of isomeric tridecyl alcohol random polyether TPE-1000 to W in the solution containing W and Mo is 0.8. After stirring evenly, the Ni-containing solution and sodium hydroxide solution (weight concentration 10%) are simultaneously dropped into the reaction slurry. The reaction temperature remains unchanged, and the reaction time is 1.0 hour. At the end of the reaction, the pH value is controlled at 8.8 to form a precipitate slurry containing nickel, molybdenum, tungsten, and aluminum. The obtained slurry is aged. The aging temperature is 78 °C. The pH value during aging is first controlled at 13.1. After aging for 0.3 hours, 1 portion of the Al-containing solution is added, and then the aging pH value is controlled at 9.6. After aging for 0.2 hours, the pH value is then controlled at 7.5, and the aging time is 0.3 hours. The above operation process is repeated 5 times to end the aging. Oleyl polyoxyethylene ether and β molecular sieve are added to the aged slurry and stirred evenly. The molar ratio of oleyl polyoxyethylene ether to Ni in the Ni-containing solution is 2.5. The obtained slurry is filtered, and the filter cake is dried for the first time at 100 °C for 9 hours, rolled, and extruded into strips. It is washed with deionized water at room temperature until neutral. Then the washed wet strips are dried as follows: First, the material is dried at 75 °C for 6.5 hours. Deionized water is evenly sprayed on the dried material, and then dried. The process of evenly spraying deionized water and drying is repeated 5 times. The volume ratio of the first spraying of deionized water to the dried material is 2.0:1, the drying temperature is 180 °C, and the drying time is 2.1 hours. The volume ratio of the second spraying of deionized water to the dried material is 1.7:1, the drying temperature is 170 °C, and the drying time is 2.1 hours. The volume ratio of the third spraying of deionized water to the dried material is 1:1, the drying temperature is 180 °C, and the drying time is 2.0 hours. The volume ratio of the fourth spraying of deionized water to the dried material is 1:1.8, the drying temperature is 180 °C, and the drying time is 1.8 hours. The volume ratio of the fifth spraying of deionized water to the dried material is 1:2.5, the drying temperature is 200 °C, and the drying time is 1.5 hours. The dried material is calcined at 540 °C for 4 hours to obtain catalyst A. The catalyst composition and main properties are shown in Table 1.

[0054] Example 2

[0055] Ammonium metatungstate and ammonium molybdate are respectively added to dissolution tank 1 filled with deionized water to prepare a mixed solution containing W and Mo. In the solution containing W and Mo, W is in the form of WO 3 with a calculated weight concentration of 48 g / L, and Mo is in the form of MoO 3The calculated weight concentration is 40 g / L. Nickel chloride is added to the dissolution tank 2 filled with deionized water to prepare a Ni-containing solution, and the weight concentration of Ni in the Ni-containing solution in terms of NiO is 60 g / L. Aluminum chloride is added to the dissolution tank 3 filled with deionized water to prepare an Al-containing solution, and Al in the Al-containing solution accounts for 38% of Al (calculated as Al 2 O 3 in the obtained hydrocracking catalyst), and it is divided into 4 equal parts by volume. Deionized water is added to the reaction tank, and the solution containing W and Mo and the sodium aluminate solution (Al calculated as Al 2 O 3The weight concentration of the solution is 17.4 g / L) and then added to the reaction tank for gelling reaction. The reaction pH is controlled at 5.8 and the reaction temperature is 70°C. After 0.7 hours of reaction, glycerol random polyether GPE-3000 is added to the reaction tank. The molar ratio of glycerol random polyether GPE-3000 to W in the solution containing W and Mo is 1.1. After stirring evenly, Ni-containing solution and sodium hydroxide solution (weight concentration is 12%) are added dropwise to the reaction slurry at the same time. The reaction temperature is kept constant and the reaction is continued. The reaction time is 1.2 hours. At the end of the reaction, the pH value is controlled at 9.2 to generate a precipitate slurry containing nickel, molybdenum, tungsten and aluminum. The resulting slurry is aged at an aging temperature of 82°C. During aging, the pH value is first controlled to 12.6. After aging for 0.1 hour, 1 equal portion of the Al-containing solution is added, and the aging pH value is controlled to 9.9. After aging for 0.15 hours, the pH value is then controlled to 7.0. The aging time is 0.2 hours. The above operation process is repeated 4 times to end aging. C12 alcohol polyoxyethylene ether and β molecular sieve are added to the aged slurry and stirred evenly. The molar ratio of C12 alcohol polyoxyethylene ether to Ni in the Ni-containing solution is 2.6. The aged slurry is filtered, and the filter cake is dried for the first time, dried at 80°C for 10 hours, rolled, and extruded. Wash with deionized water at room temperature until neutral. Then the washed wet strips were dried for the second time in the following steps: first, the material was dried at 75°C for 6.5 hours, deionized water was evenly sprayed on the dried material, and then dried, and the uniform spraying of deionized water and drying process were repeated 5 times, the volume ratio of deionized water to dry material sprayed for the first time was 2.0:1, the drying temperature was 200°C, and the drying time was 2.5 hours, the volume ratio of deionized water to dry material sprayed for the second time was 1.5:1, the drying temperature was 190°C, and the drying time was 2.0 hours, the volume ratio of deionized water to dry material sprayed for the third time was 1:1.5, the drying temperature was 180°C, and the drying time was 1.6 hours, the volume ratio of deionized water to dry material sprayed for the fourth time was 1:2.0, the drying temperature was 190°C, and the drying time was 1.8 hours, the volume ratio of deionized water to dry material sprayed for the fifth time was 1:2.4, the drying temperature was 180°C, and the drying time was 2.2 hours, and the dried material was calcined at 520°C for 6 hours to obtain catalyst B. The catalyst composition and main properties are shown in Table 1.

[0056] Example 3

[0057] Ammonium metatungstate and ammonium molybdate are added to a dissolving tank 1 filled with deionized water to prepare a solution containing W and Mo. In the solution containing W and Mo, W is WO 3 The weight concentration is 76g / L, Mo is in the form of MoO 3The calculated weight concentration is 24 g / L. Nickel chloride is added to the dissolution tank 2 filled with deionized water to prepare a mixed Ni solution. The weight concentration of Ni in the Ni-containing solution, calculated as NiO, is 56 g / L. Aluminum chloride is added to the dissolution tank 3 filled with deionized water to prepare an Al-containing solution. The Al in the Al-containing solution accounts for 40% of the Al (calculated as Al 2 O 3 in the resulting hydrocracking catalyst), and it is divided into 6 equal parts by volume. Deionized water is added to the reaction tank, and the W- and Mo-containing solution and sodium aluminate solution (Al calculated as Al 2 O 3The calculated weight concentration is 12.0 g / L) and added to the reaction tank in a cocurrent manner for gelation reaction. The reaction pH value is controlled at 5.5, the reaction temperature is 55 °C. After reacting for 0.7 hours, polyoxyethylene random lauryl ether LPE-1200 is added to the reaction tank. The molar ratio of polyoxyethylene random lauryl ether LPE-1200 to W in the solution containing W and Mo is 1.0. After stirring evenly, the Ni-containing solution and ammonia water (weight concentration of 11%) are simultaneously dropped into the reaction slurry. The reaction temperature remains unchanged, and the reaction time is 1.2 hours. At the end of the reaction, the pH value is controlled at 10.0 to form a precipitate slurry containing nickel, molybdenum, tungsten, and aluminum. The obtained slurry is aged. The aging temperature is 80 °C. The pH value during aging is first controlled at 12.8. After aging for 0.2 hours, 1 portion of the Al-containing solution is added, and then the aging pH value is controlled at 9.8. After aging for 0.15 hours, the pH value is then controlled at 7.8, and the aging time is 0.15 hours. The above operation process is repeated 6 times to end the aging. Alkylphenol polyoxyethylene 10 ether and β zeolite are added to the aged slurry and stirred evenly. The molar ratio of alkylphenol polyoxyethylene 10 ether to Ni in the Ni-containing solution is 2.4. The aged slurry is filtered, and the filter cake is dried for the first time at 90 °C for 10 hours, rolled, extruded, and formed. It is washed with deionized water at room temperature until neutral. Then, the washed wet strips are dried for the second time as follows: First, the material is dried at 78 °C for 6.8 hours. Deionized water is evenly sprayed on the dried material, and then dried. The process of evenly spraying deionized water and drying is repeated 7 times. The volume ratio of the first spraying of deionized water to the dried material is 2.0:1, the drying temperature is 180 °C, and the drying time is 2.5 hours. The volume ratio of the second spraying of deionized water to the dried material is 1.5:1, the drying temperature is 170 °C, and the drying time is 1.8 hours. The volume ratio of the third spraying of deionized water to the dried material is 1.0:1, the drying temperature is 180 °C, and the drying time is 1.8 hours. The volume ratio of the fourth spraying of deionized water to the dried material is 1:1.4, the drying temperature is 170 °C, and the drying time is 1.7 hours. The volume ratio of the fifth spraying of deionized water to the dried material is 1:1.8, the drying temperature is 180 °C, and the drying time is 1.8 hours. The volume ratio of the sixth spraying of deionized water to the dried material is 1:2.1, the drying temperature is 170 °C, and the drying time is 2.1 hours. The volume ratio of the seventh spraying of deionized water to the dried material is 1:2.6, the drying temperature is 170 °C, and the drying time is 1.8 hours. The dried material is calcined at 520 °C for 5.5 hours to obtain catalyst C. The composition and main properties of the catalyst are shown in Table 1.

[0058] Example 4

[0059] Ammonium metatungstate and ammonium molybdate are respectively added to dissolution tank 1 filled with deionized water to prepare a solution containing W and Mo. In the solution containing W and Mo, W is in the form of WO 3The calculated weight concentration is 60 g / L, and Mo is in the form of MoO 3 The calculated weight concentration is 36 g / L. Nickel chloride is added to the dissolution tank 2 filled with deionized water to prepare a Ni-containing solution. The weight concentration of Ni in the Ni-containing solution in terms of NiO is 48 g / L. Aluminum chloride is added to the dissolution tank 3 filled with deionized water to prepare an Al-containing solution. Al in the Al-containing solution accounts for 40% of Al (in terms of Al 2 O 3 in the obtained hydrocracking catalyst), and it is divided into 5 equal parts by volume. Deionized water is added to the reaction tank, and the W- and Mo-containing solution and the sodium aluminate solution (Al in terms of Al 2 O 3The calculated weight concentration (18.0 g / L) is added to the reaction tank in a countercurrent manner for gelation reaction. The reaction pH value is controlled at 5.4, the reaction temperature is 65 °C. After reacting for 0.6 hours, polypropylene glycol random polyether PPE-1500 is added to the reaction tank. The molar ratio of polypropylene glycol random polyether PPE-1500 to W in the solution containing W and Mo is 0.6. After stirring evenly, the nickel-containing solution and ammonia water (weight concentration 12%) are simultaneously dropped into the reaction slurry. The reaction temperature remains unchanged, and the reaction time is 1.4 hours. At the end of the reaction, the pH value is controlled at 10.0 to form a precipitate slurry containing nickel, molybdenum, tungsten, and aluminum. The obtained slurry is aged. The aging temperature is 75 °C. The pH value during aging is first controlled at 12.2. After aging for 0.14 hours, 1 portion of the solution containing Al is added, and then the aging pH value is controlled at 9.1. After aging for 0.2 hours, the pH value is then controlled at 6.9, and the aging time is 0.25 hours. The above operation process is repeated 5 times to end the aging. Octylphenol polyoxyethylene ether and β molecular sieve are added to the aged slurry and stirred evenly. The molar ratio of octylphenol polyoxyethylene ether to Ni in the nickel-containing solution is 1.8. The obtained slurry is filtered, and the filter cake is dried for the first time at 80 °C for 16 hours, rolled, and extruded into strips. It is washed with deionized water at room temperature until neutral. Then the washed wet strips are dried as follows: First, the material is dried at 75 °C for 7.2 hours. Deionized water is evenly sprayed on the dried material, and then it is dried. The process of evenly spraying deionized water and drying is repeated 6 times. The volume ratio of the first spraying of deionized water to the dried material is 2.5:1, the drying temperature is 220 °C, and the drying time is 2.3 hours. The volume ratio of the second spraying of deionized water to the dried material is 1.7:1, the drying temperature is 180 °C, and the drying time is 2.2 hours. The volume ratio of the third spraying of deionized water to the dried material is 1:1, the drying temperature is 170 °C, and the drying time is 2.0 hours. The volume ratio of the fourth spraying of deionized water to the dried material is 1:1.5, the drying temperature is 160 °C, and the drying time is 1.8 hours. The volume ratio of the fifth spraying of deionized water to the dried material is 1:1.9, the drying temperature is 170 °C, and the drying time is 1.8 hours. The volume ratio of the sixth spraying of deionized water to the dried material is 1:2.4, the drying temperature is 170 °C, and the drying time is 1.8 hours. The dried material is calcined at 530 °C for 5 hours to obtain catalyst D. The catalyst composition and main properties are shown in Table 1.

[0060] Comparative Example 1

[0061] The reference catalyst E is prepared according to the method disclosed in CN101239324A. The components and the content of active metals are the same as those in Example 1. The molecular sieve is β molecular sieve. The specific steps are as follows: (1) Nickel chloride, ammonium molybdate, and aluminum chloride solution are respectively added to a dissolution tank filled with deionized water. The mass concentration of Ni in the solution in terms of NiO is 52 g / L, and Mo is in terms of MoO3 The calculated weight concentration is 32 g / L, and Al is in the form of Al 2 O 3 The calculated mass concentration is 22 g / L, and 2000 mL of purified water is added for dilution; (2) Ammonia water is added under stirring until the pH value reaches 5.2; (3) A sodium tungstate solution containing WO 3 is 68 g / l, and it is added to the mixture under stirring; (4) Ammonia water is continuously added until the pH value reaches 7.8; (5) The entire gel-forming process should be carried out at 62 °C; (6) The mixture is allowed to stand and age for 4 hours within the range of 78 °C; Before aging, the β zeolite used in this preparation method is added, and the β zeolite 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 °C for 9 hours, roll, extrude and form with a perforated plate with a diameter of 3 mm; Wash with ammonium acetate solution with pH = 8.8 at room temperature; Then dry in an oven at 80 °C for 10 hours and calcine at 540 °C for 4 hours to obtain catalyst E. The composition and properties of the catalyst are shown in Table 1.

[0062] Comparative Example 2

[0063] According to the preparation method disclosed in CN106179462A, a catalyst composition reference agent F for the present invention's Example 1 is prepared. The acidic component is β zeolite, and the specific process is as follows:

[0064] Nickel chloride and aluminum chloride solutions are respectively dissolved in deionized water to prepare a mixed solution A. The weight concentration of NiO in the mixed solution A is 52 g / L, and Al 2 O 3 The weight concentration is 15.4 g / L. Ammonium metatungstate, ammonium molybdate and aluminum chloride solutions are respectively dissolved in deionized water to prepare a mixed solution B. The weight concentration of WO 3 in the mixed solution B is 68 g / L, and the weight concentration of MoO 3 is 32 g / L, and Al 2 O 3The weight concentration is 6.6 g / L. Ammonia water with a concentration of 10% (by weight) is added to solution A under stirring, the gelling temperature is maintained at 6.2 °C, the pH value at the end is controlled at 7.8, and the gelling time is controlled at 0.8 hours to generate precipitate slurry I containing nickel and aluminum. Deionized water is added to the reaction tank, and ammonia water with a concentration of 10% (by weight) and solution B are added to the reaction tank in parallel flow. The gelling temperature is maintained at 62 °C, the pH value is controlled at 7.8 during the parallel-flow gelling reaction, and the gelling time is controlled at 1.0 hour to generate precipitate slurry II containing tungsten, molybdenum, and aluminum. The above two precipitated slurries are mixed and aged. The aging time is 4.0 hours, the aging temperature is 78 °C, and the pH value is controlled at 7.6. Then, filtration is carried out, and the filter cake is subjected to hydrothermal treatment under water vapor containing urea. The conditions for hydrothermal treatment are as follows: the molar ratio of urea to the total amount of active metal atoms is 7:1, the temperature is 250 °C, the pressure is 4.0 MPa, and the treatment time is 3 hours. After the treatment, the filter cake is slurried, the β-zeolite suspension is stirred evenly into the mixture slurry, filtered, and the filter cake is dried at 100 °C for 9 hours, rolled, and extruded into strips. It is washed with deionized water to neutrality at room temperature. Then, the washed wet strips are dried at 80 °C for 10.0 hours. The dried material is calcined at 540 °C for 4 hours to obtain catalyst F. The catalyst composition, pore distribution, and main properties are shown in Table 1.

[0065] Comparative Example 3

[0066] A reference agent G identical to Example 1 of this patent is prepared, except that the acidic component is Y zeolite. The specific process is as follows:

[0067] Ammonium metatungstate and ammonium molybdate are respectively added to dissolution tank 1 filled with deionized water to prepare a solution containing W and Mo. In the solution containing W and Mo, the weight concentration of W calculated as WO 3 is 68 g / L, and the weight concentration of Mo calculated as MoO 3 is 32 g / L. Nickel chloride is added to dissolution tank 2 filled with deionized water to prepare a solution containing Ni. In the solution containing Ni, the weight concentration of Ni calculated as NiO is 52 g / L. Aluminum chloride is added to dissolution tank 3 filled with deionized water to prepare a solution containing Al. The Al in the solution containing Al accounts for 30% of the total Al (calculated as Al 2 O 3 in the obtained hydrocracking catalyst), and it is divided into 5 equal parts by volume. Deionized water is added to the reaction tank, and the solution containing W and Mo and sodium aluminate solution (Al calculated as Al 2 O 3The calculated weight concentration (15.4 g / L) is added to the reaction tank in a countercurrent manner for gelation reaction. The reaction pH value is controlled at 5.3, the reaction temperature is 62 °C. After 0.8 hours of reaction, isomeric tridecyl alcohol random polyether TPE-1000 is added to the reaction tank. The molar ratio of isomeric tridecyl alcohol random polyether TPE-1000 to W in the solution containing W and Mo is 0.8. After stirring evenly, the Ni-containing solution and sodium hydroxide solution (weight concentration 10%) are simultaneously added dropwise to the reaction slurry. The reaction temperature remains unchanged, and the reaction time is 1.0 hour. At the end of the reaction, the pH value is controlled at 8.8 to form a precipitate slurry containing nickel, molybdenum, tungsten, and aluminum. The obtained slurry is aged. The aging temperature is 78 °C. The pH value during aging is first controlled at 13.1. After 0.3 hours of aging, 1 portion of the Al-containing solution is added, and then the aging pH value is controlled at 9.6. After 0.2 hours of aging, the pH value is then controlled at 7.5, and the aging time is 0.3 hour. The above operation process is repeated 5 times to end the aging. Oleyl polyoxyethylene ether and Y zeolite are added to the aged slurry and stirred evenly. The molar ratio of oleyl polyoxyethylene ether to Ni in the Ni-containing solution is 2.5. The obtained slurry is filtered, and the filter cake is dried for the first time at 100 °C for 9 hours, rolled, and extruded into strips. It is washed with deionized water at room temperature until neutral. Then the washed wet strips are dried as follows: First, the material is dried at 75 °C for 6.5 hours. Deionized water is evenly sprayed on the dried material, and then it is dried. The process of evenly spraying deionized water and drying is repeated 5 times. The volume ratio of the first spraying of deionized water to the dried material is 2.0:1, the drying temperature is 180 °C, and the drying time is 2.1 hours. The volume ratio of the second spraying of deionized water to the dried material is 1.7:1, the drying temperature is 170 °C, and the drying time is 2.1 hours. The volume ratio of the third spraying of deionized water to the dried material is 1:1, the drying temperature is 180 °C, and the drying time is 2.0 hours. The volume ratio of the fourth spraying of deionized water to the dried material is 1:1.8, the drying temperature is 180 °C, and the drying time is 1.8 hours. The volume ratio of the fifth spraying of deionized water to the dried material is 1:2.5, the drying temperature is 200 °C, and the drying time is 1.5 hours. The dried material is calcined at 540 °C for 4 hours to obtain catalyst G. The catalyst composition and main properties are shown in Table 1.

[0068] Comparative Example 4

[0069] According to the preparation method disclosed in CN106513006A, β zeolite is added to the powder and mixed evenly to prepare reference agent H for the catalyst composition of Example 1 of the present invention. The specific process is as follows:

[0070] Nickel basic carbonate was uniformly mixed with 300 ml of deionized water and then added into a 1 L high-pressure ultrasonic reactor. The ultrasonic frequency was set at 60 KHz, and the mixture was heated to 80 °C. After keeping the temperature constant for 1 h, the ultrasonic frequency was reduced to 20 KHz, and the system temperature was raised to 120 °C. Ammonium molybdate and polyvinylpyrrolidone were added. Then, 10 ml of ammonia water with a concentration of 25 wt% was added dropwise into the system. After keeping the temperature constant for 2 h, the ultrasonic was turned off and stirring was started at a speed of 300 revolutions per minute. Ammonium metatungstate was added, and then citric acid was added until the pH of the system reached 4.2. After keeping the temperature constant for 2 h, the heating was turned off. After the system cooled to room temperature, the slurry was collected and subjected to spray drying treatment. The inlet temperature and the outlet temperature were controlled at about 200 °C and 100 °C respectively. The obtained dry powder was calcined in a muffle furnace at 330 °C for 3 h to obtain the active component powder. β zeolite was added to the powder and mixed evenly. The mixture of the active component powder and β zeolite was mixed with aluminum hydroxide dry gel accounting for 40% of the weight of the active component powder, and then 10% dilute nitric acid aqueous solution was added for kneading and extrusion to obtain a strip with a diameter of 1.5 mm. The strip was dried at 110 °C for 10 h and calcined in a muffle furnace at 400 °C for 5 h to obtain the reference agent H. The catalyst composition and main properties are shown in Table 1.

[0071] Comparative Example 5

[0072] Same as Example 1, prepare reference agent I. During the preparation process, random polyether polyoxyethylene-polyoxypropylene copolymer (random isomeric tridecyl alcohol polyether TPE-1000) was not added.

[0073] Comparative Example 6

[0074] Same as Example 1, prepare reference agent J. During the aging process of the slurry of the precipitate containing nickel, molybdenum, tungsten, and aluminum, all the Al-containing solution was added at one time, and the aging pH value was a fixed value. The specific preparation process is as follows:

[0075] Ammonium metatungstate and ammonium molybdate were respectively added into the dissolution tank 1 filled with deionized water to prepare a solution containing W and Mo. In the solution containing W and Mo, the weight concentration of W calculated as WO 3 was 68 g / L, and the weight concentration of Mo calculated as MoO 3 was 32 g / L. Nickel chloride was added into the dissolution tank 2 filled with deionized water to prepare a solution containing Ni. In the solution containing Ni, the weight concentration of Ni calculated as NiO was 52 g / L. Aluminum chloride was added into the dissolution tank 3 filled with deionized water to prepare a solution containing Al. The Al in the solution containing Al accounted for 30% of the total Al (calculated as Al 2 O 3 in the obtained hydrocracking catalyst. Deionized water was added into the reaction tank, and the solution containing W and Mo and sodium aluminate solution (Al calculated as Al 2 O 3The calculated weight concentration is 15.4 g / L and it is added to the reaction tank in a cocurrent manner for gelation reaction. The reaction pH value is controlled at 5.3, the reaction temperature is 62 °C. After reacting for 0.8 hours, isomeric tridecyl alcohol random polyether TPE-1000 is added to the reaction tank. The molar ratio of W in isomeric tridecyl alcohol random polyether TPE-1000 to W in the solution containing W and Mo is 0.8. After stirring evenly, the Ni-containing solution and sodium hydroxide solution (weight concentration is 10%) are simultaneously dropped into the reaction slurry. The reaction temperature remains unchanged, the reaction time is 1.0 hour, and the pH value at the end of the reaction is controlled at 8.8 to generate a precipitate slurry containing nickel, molybdenum, tungsten, and aluminum. The obtained slurry is aged. All of the Al-containing solution is added at the start of aging. The aging temperature is 78 °C, the pH value during aging is controlled at 8.5, and after aging for 4.0 hours, the aging ends. Oleyl polyoxyethylene ether and β molecular sieve are added to the aged slurry and stirred evenly. The molar ratio of oleyl polyoxyethylene ether to Ni in the Ni-containing solution is 2.5. The obtained slurry is filtered, and the filter cake is dried for the first time, dried at 100 °C for 9 hours, rolled, and extruded into strips. It is washed with deionized water at room temperature until neutral. Then the washed wet strips are dried as follows: First, the material is dried at 75 °C for 6.5 hours. Deionized water is evenly sprayed on the dried material, and then it is dried. The process of evenly spraying deionized water and drying is repeated 5 times. The volume ratio of the first spraying of deionized water to the dried material is 2.0:1, the drying temperature is 180 °C, and the drying time is 2.1 hours. The volume ratio of the second spraying of deionized water to the dried material is 1.7:1, the drying temperature is 170 °C, and the drying time is 2.1 hours. The volume ratio of the third spraying of deionized water to the dried material is 1:1, the drying temperature is 180 °C, and the drying time is 2.0 hours. The volume ratio of the fourth spraying of deionized water to the dried material is 1:1.8, the drying temperature is 180 °C, and the drying time is 1.8 hours. The volume ratio of the fifth spraying of deionized water to the dried material is 1:2.5, the drying temperature is 200 °C, and the drying time is 1.5 hours. The dried material is calcined at 540 °C for 4 hours to obtain catalyst J. The catalyst composition and main properties are shown in Table 1.

[0076] Comparative Example 7

[0077] Same as Example 1, reference agent K is prepared. During the preparation process, the second drying of the molded product after washing adopts the first drying condition (conventional drying condition). The specific preparation process is as follows:

[0078] Ammonium metatungstate and ammonium molybdate are respectively added to dissolution tank 1 filled with deionized water to prepare a solution containing W and Mo. In the solution containing W and Mo, the weight concentration of W calculated as WO 3 is 68 g / L, and the weight concentration of Mo calculated as MoO 3The calculated weight concentration is 32 g / L. Nickel chloride is added to the dissolution tank 2 filled with deionized water to prepare a Ni-containing solution. The weight concentration of Ni in the Ni-containing solution in terms of NiO is 52 g / L. Aluminum chloride is added to the dissolution tank 3 filled with deionized water to prepare an Al-containing solution. The Al in the Al-containing solution accounts for 30% of the total Al (in terms of Al 2 O 3 in the obtained hydrocracking catalyst), and it is divided into 5 equal parts by volume. Deionized water is added to the reaction tank, and the solution containing W and Mo and the sodium aluminate solution (the weight concentration of Al in terms of Al 2 O 3 is 15.4 g / L) are added to the reaction tank in parallel for gelation reaction. The reaction pH value is controlled at 5.3, the reaction temperature is 62 °C. After reacting for 0.8 hours, the isomeric tridecanol random polyether TPE-1000 is added to the reaction tank. The molar ratio of the isomeric tridecanol random polyether TPE-1000 to W in the solution containing W and Mo is 0.8. After stirring evenly, the Ni-containing solution and the sodium hydroxide solution (weight concentration 10%) are simultaneously added dropwise to the reaction slurry. The reaction temperature remains unchanged, and the reaction time is 1.0 hour. The pH value at the end of the reaction is controlled at 8.8 to form a precipitate slurry containing nickel, molybdenum, tungsten, and aluminum. The obtained slurry is aged. The aging temperature is 78 °C. The pH value during aging is first controlled at 13.1. After aging for 0.3 hours, 1 part of the Al-containing solution is added, and then the aging pH value is controlled at 9.6. After aging for 0.2 hours, the pH value is then controlled at 7.5, and the aging time is 0.3 hours. The above operation process is repeated 5 times to end the aging. Oleyl polyoxyethylene ether and β zeolite are added to the aged slurry and stirred evenly. The molar ratio of oleyl polyoxyethylene ether to Ni in the Ni-containing solution is 2.5. The obtained slurry is filtered, and the filter cake is dried for the first time at 100 °C for 9 hours, rolled, and extruded into strips. It is washed with deionized water at room temperature until neutral. The washed wet strips are dried at 100 °C for 9 hours, and the dried material is calcined at 540 °C for 4 hours to obtain catalyst K. The catalyst composition and main properties are shown in Table 1.

[0079] Example 5

[0080] This example is an experiment for evaluating the activity of the catalyst of the present invention and is compared with the catalysts of the comparative examples. Catalysts A, B, C, D of the present invention and catalysts E, F, G, H, I, J, K of the comparative examples are respectively used to conduct a comparative evaluation test on a 200 mL small-scale hydrogenation device. The comparative evaluation test is carried out on a 200 mL small-scale hydrogenation device. The evaluation conditions are: the total reaction pressure is 15.7 MPa, the hydrogen-oil volume ratio is 1200:1, the liquid hourly space velocity is 1.6 h -1 , the reaction temperatures are 378 °C and 385 °C. The raw material for evaluation is vacuum gas oil, and its main properties are shown in Table 3. The evaluation results are shown in Tables 4 - 5.

[0081] As can be seen from Tables 1 to 2, the catalyst of the present invention has a large amount of surface active metals and a hierarchical pore distribution. From the process conditions of the catalyst activity evaluation and the evaluation results, it can be seen that compared with the catalyst of the comparative example, the distribution of active metals and pore size distribution of the catalyst of the present invention are beneficial to improving the aromatic saturation performance. In the process of hydrocracking of heavy feedstock oil, the catalyst of the present invention has both high isomerization performance and high aromatic saturation performance. The properties such as the pour point and aromatic content of the diesel fraction can meet the standards of industrial white oil and transformer oil, and can flexibly produce special oils such as transformer oil and white oil, and raw materials for high viscosity index lubricating oil base oil. The catalyst of the comparative example cannot have both high isomerization performance and high aromatic saturation performance at the same time. The hydrocracking catalyst of the present invention still has good stability and good product quality under the condition of high nitrogen content feed.

[0082] Table 1 Composition and properties of catalysts prepared in examples and comparative examples

[0083]

[0084] Table 1 (continued) Composition and properties of catalysts prepared in examples and comparative examples

[0085]

[0086] Table 2 Ratio of weight content of surface active metal oxide to bulk active metal oxide of the catalyst

[0087] of the catalyst

[0088]

[0089] Continued Table 2

[0090]

[0091] Table 3 Main properties of feedstock oil

[0092]

[0093] Table 4 Evaluation results of catalysts in examples and comparative examples (running for 250 hours)

[0094]

[0095] Continued Table 4 Evaluation results of catalysts in examples and comparative examples (running for 250 hours)

[0096]

[0097] Table 5 Evaluation results of catalysts in examples and comparative examples (running for 2000 hours)

[0098]

[0099] Table 6 Properties of β zeolite in Examples and Comparative Examples

[0100]

[0101] Table 7 Properties of Y zeolite used in the present invention

[0102]

Claims

1. A preparation method of a bulk-phase hydrocracking catalyst, characterized in that it comprises: (1) A solution containing W and Mo and a sodium aluminate solution are added to a reaction tank in parallel for gelation reaction. After the reaction, an organic auxiliary agent P1 is added. The pH value of the gelation reaction is 5-6; (2) A solution containing Ni and a precipitating agent are added to the reaction slurry obtained in step (1), and the obtained slurry is aged by decreasing the pH value in three stages for n times. Each time, 1 / n of the solution containing Al is added at the end of the first-stage pH value aging, where n is 2-8; The specific process of each three-stage decreasing pH value aging is as follows: the aging temperature of each stage is 60-98 °C; in the first stage, the pH value is 11.0-13.5, and the aging time is 0.05-0.5 hours. After the aging ends, 1 / n of the solution containing Al is added; in the second stage, the pH value is adjusted to 8.5-10.5, and the aging time is 0.05-0.5 hours; in the third stage, the pH value is adjusted to 5.5-8.3, and the aging time is 0.05-0.5 hours; After the aging ends, an organic auxiliary agent P2 and a β-zeolite slurry are added and mixed evenly, and the obtained slurry is filtered; (3) The material obtained in step (2) is first dried, rolled, formed, washed, and then dried and calcined for the second time to obtain a bulk-phase hydrocracking catalyst; where the organic auxiliary agent P1 is a random polyether polyoxyethylene-polyoxypropylene copolymer; the organic auxiliary agent P2 is a polyoxyethylene-type non-ionic surfactant; The second drying process in step (3) is as follows: a. First, the material is dried at 60-100 °C for 1.0-8.5 hours; b. Water is evenly sprayed on the material obtained in step a. The volume ratio of the added water to the volume of the dried material is 1:4-4:1, and then it is dried at a temperature of 150-280 °C for 0.5-4.0 hours; c. Repeat the process of step b 2-9 times; where, the volume ratio of the first added water to the volume of the dried material is greater than 1:1, and the volume ratio of the last added water to the volume of the dried material is less than 1:

1.

2. The method according to claim 1, characterized in that: In the solution containing W and Mo in step (1), the weight concentration of W calculated as WO 3 is 5 to 120 g / L, and the weight concentration of Mo calculated as MoO 3 is 5 to 110 g / L; the concentration of the sodium aluminate solution is 5 to 90 g / L in terms of the concentration of Al 2 O 3 .

3. The method according to claim 1, characterized in that: The conditions of the gelation reaction in step (1) are: the reaction temperature is 30-95 °C, and the reaction time is 0.1-1.0 hours.

4. The method according to claim 1, characterized in that: The random polyether polyoxyethylene-polyoxypropylene copolymer described in step (1) is selected from at least one of isomeric tridecanol random polyether TPE-1000, propylene glycol random polyether PPE-1500, glycerol random polyether GPE-3000, butanol random polyether BPE-1000, butanol random polyether BPE-1500, butanol random polyether BPE-2500, lauric acid random polyether LPE-1200, and dodecanol random polyether CPE-1500; The molar ratio of the organic auxiliary agent P1 to W in the solution containing W and Mo is 0.2-1.

8.

5. The method according to claim 1, characterized in that: In the Ni-containing solution described in step (2), the weight concentration of Ni calculated as NiO is 5 to 130 g / L; in the Al-containing solution, the weight concentration of Al calculated as Al 2 O 3 is 5 to 70 g / L.

6. The method according to claim 1, characterized in that: The precipitating agent described in step (2) is an alkaline precipitating agent, selected from one or more of sodium carbonate, sodium bicarbonate, ammonia water, sodium hydroxide, potassium hydroxide, potassium carbonate or potassium bicarbonate.

7. According to the method described in claim 1, it is characterized in that: In step (2), the Al added through the solution containing Al accounts for 5% to 55% of the total Al in the obtained hydrocracking catalyst in terms of Al 2 O 3 calculated as.

8. According to the method described in claim 1, it is characterized in that: The polyoxyethylene non-ionic surfactant described in step (2) is selected from one or several of C16-18 alcohol polyoxyethylene ether, C12-14 alcohol polyoxyethylene ether, oleyl alcohol polyoxyethylene ether, isodecyl alcohol polyoxyethylene ether, octylphenol polyoxyethylene ether, castor oil polyoxyethylene ether, alkylphenol polyoxyethylene ether, and dodecylamine polyoxyethylene ether; the molar ratio of the organic auxiliary agent P2 to Ni in the Ni-containing solution is 0.8:1 to 4.5:

1.

9. According to the method described in claim 1, it is characterized in that: The β zeolite described in step (2) has the following properties: the molar ratio of silicon oxide to aluminum oxide is 30 to 90; the specific surface area is 430 to 780 m 2 / g; the pore volume is 0.30 to 0.90 cm 3 / g; the infrared acid amount is 0.10 to 0.45 mmol / g.

10. According to the method described in claim 1, it is characterized in that: The first drying conditions described in step (3) are as follows: drying at 40-150 °C for 1-48 hours; adding one or more of a glue solvent and an extrusion aid during the forming process; the glue solvent is one or more of hydrochloric acid, nitric acid, sulfuric acid, acetic acid, and oxalic acid, and the extrusion aid is one or more of sesbania powder, carbon black, graphite powder, and citric acid. The amount of the extrusion aid accounts for 1wt% - 10wt% of the total dry basis of the materials.

11. According to the method described in claim 1, it is characterized in that: During the second drying process, the volume ratio of the added water to the volume of the dried material decreases successively with the increase in the number of drying times.

12. According to the method described in claim 1, it is characterized in that: The total drying time for the second drying is 5-40 hours.

13. According to the method described in claim 1, it is characterized in that: The calcination conditions described in step (3) are as follows: the calcination temperature is 350-650 °C, and the calcination time is 1-24 hours.

14. A bulk-phase hydrocracking catalyst prepared by the method according to any one of claims 1-13, it is characterized in that: The catalyst comprises a hydrogenation active metal component, amorphous alumina and beta zeolite; the catalyst particles comprise an outer surface layer, an intermediate layer and a central core, and the average pore diameter decreases in a gradient manner, that is, 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 on the cross-section of the catalyst particles, the length from the outermost edge to the center point 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 rest is the central core; the molar ratio of W / Mo is 1:5-23:1, and the molar ratio of Ni / (Mo + W) is 1:12-16:1; wherein the sum of the weight contents of the surface active metal components WO 3 and NiO and the sum of the weight contents of the bulk active metal components WO 3 and NiO is in the ratio of 2.3:1-6.0:1, and the sum of the weight contents of the surface active metal components MoO 3 and NiO and the sum of the weight contents of the bulk active metal components MoO 3 and NiO is in the ratio of 1.5:1-4.7:

1.

15. According to the catalyst described in claim 14, it is characterized in that: Based on the weight of the bulk hydrocracking catalyst, the total content of Ni, W, and Mo in terms of oxides is 71% - 93%, the content of amorphous alumina is 2% - 21%, and the content of β zeolite is 5% - 23%; the specific surface area is 220 - 600 m 2 / g, and the pore volume is 0.35 - 1.00 mL / g.

16. According to the catalyst described in claim 14, it is characterized in that: The bulk-phase hydrocracking catalyst is in the form of solid particles, and the particle size of the catalyst particles is 1-10 mm.

17. Application of a bulk-phase hydrocracking catalyst prepared by the method according to any one of claims 1-13 in the hydrocracking process for producing special oils and base oils of lubricating oils.

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