Process for the preparation of a phosphorus-containing hydrofinishing catalyst

Abstract

The application discloses a preparation method of a phosphorus-containing hydrorefining catalyst, and comprises the following steps: (1) adding deionized water and phosphate into a gelatinization reaction tank, continuously feeding CO2, and adding a W, Mo and Al-containing solution and a precipitant into the reaction tank to perform a first gelatinization reaction, so as to obtain slurry I; (2) adding a Ni-containing solution and a precipitant into the slurry I drop by drop to perform a second gelatinization reaction, performing n times of aging, adjusting the pH value by using 1 / n sodium metaaluminate solution in each aging process, filtering slurry III obtained after aging, and obtaining solid-phase materials; and (3) performing first drying, shaping and washing on the solid-phase materials, and then performing second drying and calcination, so as to obtain the phosphorus-containing hydrorefining catalyst. The bulk-phase hydrorefining catalyst prepared by the method has a stepped pore size distribution, small and uniformly-distributed oxide particle sizes, and a large surface active site density, and is suitable for application in heavy distillate oil hydrogenation de-aromatic, ultra-deep hydrogenation desulfurization and denitrification reactions.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of catalyst preparation, and particularly relates to a preparation method of a phosphorus-containing hydrofining catalyst for distillate oil. BACKGROUND

[0002] Domestic oil refining enterprises have multiple hydrofining devices, producing a large amount of diesel distillate products. In particular, with increasingly stringent environmental protection regulations, reducing diesel quantity is the direction of efforts, and oil conversion and oil special development. At present, in order to cope with the low aromatization trend in current oil quality upgrading, especially to solve the problem of multi-ring aromatic content limitation, and to achieve precise hydrogenation, the most fundamental way is to start from the catalyst itself.

[0003] The combination of active metal components in the hydrogenation catalyst is better than the single component activity, and the hydrogenation saturation activity of the W-Ni combination in the combination of metal components is the best, and the hydrogenation denitrification of the Mo-Ni combination is the best. The bulk catalyst is the highest activity hydrogenation catalyst at present, and the active metal content reaches more than 70%. The bulk hydrogenation catalyst can break away from the limitation of metal content, and can arbitrarily adjust the proportion of each active component in the catalyst to improve the hydrogenation performance of the catalyst. In the bulk catalyst, the size and distribution of metal oxide particles have a great influence on the distribution of hydrogenation active metals and the interaction between different hydrogenation active metals, which further affects the hydrogenation activity of the bulk catalyst. At the same time, the pore size and specific surface area of the catalyst also affect the hydrogenation activity of the bulk catalyst, and the smaller the pore size of the catalyst, the larger the molecular reactant cannot pass through the catalyst pores. The smaller the catalyst surface, the uneven distribution of active metals will cause disordered distribution of different hydrogenation active metals, and the high content of metals in the bulk catalyst will cause excessive accumulation of metal particles, which reduces the generation of active phase,

[0004] CN1951561A discloses a method for preparing a hydrogenation catalyst by co-precipitation, and the catalyst uses active metals Ni and W components to co-precipitate with a precipitator to form a Ni x W y O z The composite oxide precursor can be added with an aluminum salt solution, or the aluminum hydroxide can be directly added after gelation, and then mixed with MoO3 by beating, filtered, shaped, and activated to form the final catalyst. The bulk catalyst prepared by the method has small pore volume and specific surface area, and the active metal is excessively accumulated, which reduces the utilization rate of the active metal.

[0005] CN110975911A discloses a bulk phase catalyst and a preparation method thereof. A compound containing Group VIII elements and a compound containing Group VIB elements are formulated into a mixed solution, the pH value of the mixed solution is adjusted to 6-11, then a surfactant is added, and the reaction is carried out in a closed container, the reaction time is at least 10 minutes, and the reaction temperature is 5-75℃. The mixed solution is heated to 80-200℃ for reaction, the reaction time is at least 1 hour, and the bulk phase catalyst is obtained by filtration and drying. The method introduces a seed generation reaction in the catalyst preparation process and adds a surfactant, but the pore volume and specific surface area of the obtained bulk phase catalyst are small.

[0006] CN103861609A discloses a preparation method of a non-supported high-activity hydrogenation catalyst. An acidic solution A containing at least one Group VIII metal compound and an alkaline solution B containing at least one silicon source or aluminum source are slowly mixed into a precipitation reactor to carry out a co-precipitation reaction at a temperature of 20-120℃ and a pH value of 7-12. The obtained slurry is aged, filtered, washed, dried, shaped, and calcined. The hydrogenation catalyst prepared by the method has a higher specific surface area and a larger pore volume, but the obtained material has poor adhesion and can only be shaped into tablets, not into strips.

[0007] CN109692686A discloses a hydrofining catalyst and a preparation method thereof. The hydrofining catalyst is a bulk phase hydrofining catalyst. Mixed solution A and a precipitator are added into a reaction tank to carry out a gelation reaction, generating a precipitate slurry I containing nickel, aluminum, and tungsten. The obtained slurry I is aged. MoO3 is slurried with water to obtain a MoO3 slurry. Mixed solution B and the precipitator are added into the aged slurry I in a concurrent manner to carry out a gelation reaction, generating a precipitate slurry II containing nickel, molybdenum, tungsten, and aluminum. The obtained material is dried, shaped, washed, dried again, and calcined to obtain the hydrofining catalyst. Although the method changes the gelation reaction conditions to make the average stacking number of MoS2 / WS2 of the catalyst 6.0-9.0 layers and the average length of MoS2 / WS2 lamella 4.0-6.5 nm, the metal oxide particles are large, the content of surface active metal is low, and the effect of saturating aromatic hydrocarbons in heavy oil is poor.

[0008] CN106179380A discloses a preparation method of a hydrofining catalyst. The method prepares nickel and aluminum precipitates by a positive addition method, and prepares tungsten, silicon, and aluminum precipitates by a concurrent method. The filter cake of the precipitates is subjected to hydrothermal treatment in steam containing urea. The precipitates prepared by the positive addition method and the concurrent method have different particle sizes, and although the distribution of different hydrogenation active metals can be controlled, the different particle sizes of the precipitates affect the distribution of active metals on the surface of the catalyst.

[0009] CN108786834A discloses a bulk phase hydrogenation catalyst and a preparation method thereof. The catalyst is a spherical particle, and the preparation process is divided into three steps: in the first step, an acidic solution I containing active metal, aluminum and ionic liquid is reacted with an alkaline I solution containing aluminum and active metal, and the pH value is adjusted to 9.0-11.0; in the second step, the reaction slurry obtained in the first step is reacted with an acidic solution II containing active metal, aluminum and ionic liquid, and the pH value is adjusted to 3.0-5.0; in the aging process, an alkaline II containing aluminum and active metal and ionic liquid are continuously added, and the pH value is adjusted to 7.0-8.0; after aging, filtration, drying and calcination, the bulk phase hydrogenation catalyst is obtained. Although the method has larger pore size, optimized pore size gradient distribution from inside to outside, effectively increases the pore size of the catalyst outside, and more active metal can be exposed to the surface of the catalyst pore, the oxide particles in the catalyst are relatively large, the active metal is easy to aggregate, the activity center of the catalyst is not effectively increased, and at the same time, the obtained oxide material has poor adhesion, and can only be spheroidized.

[0010] In the existing coprecipitation method for preparing bulk phase catalyst technology, different precipitation methods and gel forming conditions have a great influence on the particle size of the active metal oxide particles, the pore size distribution, further affect the distribution of the hydrogenation active metal on the catalyst surface and the interaction relationship between different hydrogenation active metals, therefore, how to control the particle size of the active metal oxide particles, increase the content of the surface phase active metal and the activity center density in the catalyst, improve the utilization rate of the surface phase hydrogenation active metal component, and match the particle size of the metal oxide in the catalyst, the active metal distribution and the pore structure are the key to improve the hydrogenation performance of the bulk phase hydrogenation refining catalyst. SUMMARY

[0011] In view of the deficiencies of the prior art, the present application provides a preparation method of a phosphorus-containing hydrogenation refining catalyst. The method prepares a bulk phase hydrogenation refining catalyst, which has a stepped pore size distribution, small and uniform oxide particle size, large surface phase active site density, high hydrogenation saturation reaction performance, and is particularly suitable for application in heavy distillate oil hydrogenation de-aromatic, ultra-deep hydrogenation desulfurization and denitrification reactions.

[0012] The preparation method of the phosphorus-containing hydrofining catalyst comprises the following steps: (1) adding deionized water and phosphate ester into a gelatinization reaction tank, continuously introducing CO2, and adding a W, Mo and Al-containing solution and a precipitant into the reaction tank to perform a first gelatinization reaction to obtain slurry I; (2) adding a Ni-containing solution and a precipitant dropwise into the slurry I obtained in the step (1) to perform a second gelatinization reaction to obtain slurry II, and continuously performing n times of aging on the slurry II, wherein n is an integer of 2-8, the pH value is adjusted by using 1 / n sodium metaaluminate solution during each aging process, and the slurry III obtained after aging is filtered to obtain a solid-phase material; and (3) performing first drying, molding and washing on the solid-phase material obtained in the step (2), and then performing second drying and calcination to obtain the phosphorus-containing hydrofining catalyst.

[0013] In the method, the phosphate ester in the step (1) is one or more of octadecyl ether phosphate (O-5P), alkylphenol ether phosphate (TXP-4, TXP-10), isomeric tridecanol ether phosphate (E-1310P), lauryl alcohol ether phosphate (MOA-3P, MOA-9P), castor oil phosphate, octadecyl phosphate and lauryl phosphate, and preferably one or more of alkylphenol ether phosphate (TXP-4, TXP-10), isomeric tridecanol ether phosphate (E-1310P), lauryl alcohol ether phosphate (MOA-3P, MOA-9P) and castor oil phosphate. The molar ratio of the phosphate ester to Al in the W, Mo and Al-containing solution in the step (1) is 0.2:1-2.0:1, and preferably 0.3:1-1.8:1.

[0014] In the method, the concentration of the CO2 gas in the step (1) is 40v%-70v%, and the flow rate of the CO2 gas is 30-120mL / min, until the CO2 gas is stopped after the gelatinization reaction is completed.

[0015] In the method, the W-containing solution in the step (1) has a W concentration of 5-120g / L (calculated as WO3), preferably 10-110g / L, a Mo concentration of 5-110g / L (calculated as MoO3), preferably 10-100g / L, and an Al concentration of 2-90g / L (calculated as Al2O3), preferably 6-85g / L. When the W, Mo and Al-containing solution is prepared, the commonly used tungsten source is ammonium metatungstate, the commonly used molybdenum source is ammonium molybdate, and the commonly used aluminum source is one or more of aluminum nitrate, aluminum sulfate, aluminum chloride and aluminum acetate.

[0016] In the method, the first gelatinization reaction in the step (1) is performed under the following conditions: the reaction temperature is 30-95℃, preferably 40-95℃, the reaction pH value is controlled to be 5-6, and the reaction time is 0.1-1.0 hours.

[0017] In the method, the weight concentration of Ni in the Ni-containing solution in step (2) is 5-130 g / L, preferably 12-120 g / L; when the Ni-containing solution is prepared, the nickel source is generally one or more of nickel sulfate, nickel nitrate and nickel chloride; the weight concentration of Al in the sodium metaaluminate solution is 5-70 g / L, preferably 8-60 g / L.

[0018] In the method, the precipitants in steps (1) and (2) are all alkaline precipitants, which are selected from one or more of sodium carbonate, sodium bicarbonate, ammonia, sodium hydroxide, potassium hydroxide, potassium carbonate and potassium bicarbonate, and are preferably ammonia and sodium hydroxide solution, the concentration of the ammonia being 5wt%-15wt% and the concentration of the sodium hydroxide solution being 7wt%-20wt%.

[0019] In the method, the second gelation reaction in step (2) is carried out under the following conditions: the reaction temperature is 30-95°C, preferably 40-95°C, the pH value at the end of the reaction is controlled to be 8.0-10.0, and the reaction time is 0.5-2.5 hours; preferably, the temperature of the reaction in step (2) is the same as that of the reaction in step (1).

[0020] In the method, the weight concentration of Al in the sodium metaaluminate solution in step (2) is 5-70 g / L, preferably 7-65 g / L. The sodium metaaluminate solution is divided into 2-8 parts by volume according to the number of times of addition, and is preferably divided into equal parts by volume.

[0021] In the method, the slurry in step (2) is preferably continuously subjected to n times of three-stage pH aging with a decreasing pH value each time; when the pH value is adjusted in the first stage, 1 / n of the sodium metaaluminate solution is used for the adjustment;

[0022] The specific process of each three-stage pH aging with a decreasing pH value is as follows: the aging temperature of each stage is 60-98°C, preferably 65-92°C; in the first stage, the reaction slurry is dropped into 1 / n of the sodium metaaluminate solution for pH adjustment, the pH value is controlled to be 11.5-13.5, and the aging time is 0.05-0.5 hours; in the second stage, the pH value is adjusted to be 8.0-10.0, and the aging time is 0.05-0.5 hours; in the third stage, the pH value is adjusted to be 4.0-6.5, and the aging time is 0.05-0.5 hours; and so on (i.e. the pH value is controlled to be 11.5-13.5 again, and the aging time is 0.05-0.5 hours, wherein n is an integer of 2-8).

[0023] In the aging process, in addition to using sodium metaaluminate solution in the first pH value adjustment, the acids and bases used in the adjustment of pH value can be inorganic salts, inorganic acids and inorganic bases containing no 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 and sodium hydroxide; the concentration and amount of the acid and base solution can be adjusted according to the actual preparation needs.

[0024] In the method, in step (2), the Al added by the sodium metaaluminate solution accounts for 5% to 55%, preferably 6% to 50%, of the total Al in the obtained hydrofining catalyst in terms of Al2O3.

[0025] In the method, the first drying, forming and washing in step (3) can be carried out by using conventional methods in the art. The first drying conditions are as follows: drying at 40-150°C for 1-48 hours, preferably drying at 50-120°C for 4-36 hours. During the forming process, conventional forming aids such as one or more of a peptizing agent, an extrusion aid and the like can be added as needed. The peptizing agent is one or more of hydrochloric acid, nitric acid, sulfuric acid, acetic acid, oxalic acid and the like, and the extrusion aid refers to a substance that is beneficial to extrusion forming, such as one or more of sesbania powder, carbon black, graphite powder, citric acid and the like, and the amount of the extrusion aid accounts for 1wt% to 10wt% of the total material dry basis. The washing is generally carried out by using deionized water or a solution containing decomposable salts (such as ammonium acetate, ammonium chloride, ammonium nitrate and the like) until neutral.

[0026] The drying conditions of the second drying in step (3) are as follows:

[0027] a. first dry the material at 60-100°C for 1.0-8.5 hours, preferably at 70-90°C for 2.0-8.0 hours;

[0028] b. uniformly spray water (preferably deionized water) on the material obtained in step a, the volume ratio of water to dry material is 1:4-4:1, and then dry at a temperature of 150-280°C, preferably 150-250°C, for 0.5-4.0 hours, preferably 0.6-3.5 hours;

[0029] c. repeat step b for 2-9 times, preferably 3-8 times.

[0030] Further, the volume ratio of water to dry material is greater than 1:1 in the first time, and the volume ratio of water to dry material is less than 1:1 in the last time, and further, the volume ratio of water to dry material decreases with the increase of the number of drying.

[0031] Further, the total drying time of the second drying is preferably 5-40 hours, and further preferably 7-38 hours.

[0032] In the method of the present application, the calcination conditions in step (3) are as follows: calcination at 350-650℃ for 1-24 hours, preferably calcination at 400-600℃ for 2-12 hours.

[0033] The present application also provides a phosphorus-containing hydrofining catalyst, which is a bulk hydrofining catalyst, and the total content of Ni, W and Mo in terms of oxides is 35%-95%, preferably 50%-90%, the content of alumina is 5%-65%, preferably 10%-50%, and the total content of phosphorus in terms of P2O5 is 2%-17%, preferably 3%-15%, based on the weight of the catalyst; the molar ratio of W / Mo is 1:13-10:1, preferably 1:11-9:1, and the molar ratio of Ni / (Mo+W) is 1:14-13:1, preferably 1:12-12:1; 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 2.5:1-6.5:1, preferably 3.0:1-6.0:1, 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 2.3:1-5.5:1, preferably 2.5:1-5.0:1; the content of the surface active metals of the catalyst is determined by X-ray photoelectron spectroscopy (XPS), and the content of the bulk active metals of the catalyst is determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES).

[0034] The phosphorus-containing hydrofining catalyst of the present application is in the form of (solid) particles, and 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, 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 10-18 nm, the average pore diameter of the intermediate layer is 7-10 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 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 rest is the central core.

[0035] In the phosphorus-containing hydrofining catalyst of the present application, the average particle size of the tungsten, molybdenum and nickel active metal oxide particles is 8-13 nm. Preferably, the particle size distribution of the oxide particles is as follows: the number of particles with a particle size less than 8 nm accounts for 3%-14% of the total number of particles, the number of particles with a particle size of 8-13 nm accounts for 71%-88% of the total number of particles, and the number of particles with a particle size greater than 13 nm accounts for 5%-17% of the total number of particles.

[0036] The specific surface area of the phosphorus-containing hydrofining catalyst of the present application is 200-500 m 2 / g, and the pore volume is 0.25-1.0 mL / g.

[0037] The hydrogenation refining catalyst of the present application can be prepared by using conventional forming methods and can have various shapes commonly used for hydrogenation refining catalysts, such as a cylindrical shape or a spherical shape. The spherical shape can be a round ball shape or an ellipsoidal shape, and the cylindrical shape can be a round column shape, a square column shape or a special-shaped (such as a trilobal shape or a quadrilobal shape) cross-section column shape. The particle size of the catalyst particles is 1-10 mm. When the catalyst particles are generally cylindrical, the length can be 2-10 mm and the particle size can be 1-6 mm. When the catalyst particles are generally spherical, the particle size is 2-10 mm.

[0038] The present application also provides the use of the hydrogenation refining catalyst in the ultra-deep hydrodesulfurization, hydrodenitrogenation and hydrodearomatization of a heavy diesel oil fraction, wherein the heavy diesel oil fraction has an aromatic content of 50wt%-85wt% and a cetane number of less than 24.

[0039] Compared with the prior art, the present application has the following advantages:

[0040] 1. In the method for preparing the hydrogenation refining catalyst, the CO2 gas is introduced to control the gas concentration and flow rate to obtain ideal micro-bubbles of the reaction liquid, and the micro-bubbles produced have small volume, are constantly free in water and collide irregularly. Under the combined action of the phosphate ester and the micro-bubbles of the reaction liquid, the particle size of the metal oxides in the catalyst is small, which helps to improve the dispersion of the active metals, reduce the probability of the generation of micropores, increase the pore volume and specific surface area of the bulk catalyst, and the suitable pore size can improve the diffusion efficiency of the catalytic process. The particle size of the oxide particles in the hydrogenation refining catalyst prepared by the present application is small and uniform, which further increases the content of the active metals in the surface catalyst.

[0041] 2. In the present application, the W-, Mo- and Al-containing solution is first precipitated, and the Ni-containing solution is added dropwise in the obtained slurry at a specific pH value. The specific addition sequence, the corresponding pH value control and the active metal precipitation sequence optimize the pore size distribution and the dispersion of the active metals of the obtained catalyst, and the content of the active metals in the surface phase is significantly increased.

[0042] 3. In the present application, the pH value is swung during aging and the sodium metaaluminate solution is added in several times. The amorphous oxides in the oxide particles are dissolved by swinging the pH value, and the size of the oxide particles is modified by adding the sodium metaaluminate solution. After the pH value is swung for n times, the growth of the oxide particles is controlled, the oxide particles are more uniform, more active metals are exposed in the surface phase, the macropores in the bulk catalyst are increased, the macromolecular reactants can easily pass through the pores, meanwhile, the aluminum introduced by the sodium metaaluminate solution increases the surface hydroxyl groups, which further enhances the adhesion of the oxides and is beneficial to the forming of the bulk catalyst.

[0043] 4. In the second drying process after molding, the present invention employs a drying method that ensures the catalyst particles have a pore distribution where the average pore diameter decreases from the outer surface layer to the central core. This reduces the diffusion effect of large molecules and other reactants with larger molecular diameters when entering and exiting the catalyst pores, thereby improving the catalyst's diffusion performance for large molecules. It also enhances the hydrogenation effect of tungsten, nickel, and molybdenum active metals on the catalyst surface on large molecules and other reactants with larger diameters. This effectively utilizes the high-density active metals on the surface of the bulk catalyst and reduces the inhibitory effect of nitrides on the hydrodesulfurization reaction.

[0044] This invention provides a method for preparing hydrorefining catalysts. Through comprehensive control of the preparation steps and conditions, the resulting bulk catalyst exhibits small and uniform metal oxide particles, high hydrogenation active sites on the catalyst surface, and a stepped pore size distribution. This enhances the hydrorefining activity for heavy oil processing, particularly benefiting aromatic saturation, effectively reducing polycyclic aromatic hydrocarbon content, and increasing cetane number. The hydrorefining catalyst prepared by this method possesses high performance in hydrodesulfurization, hydronitrogenation, and aromatic saturation reactions, making it particularly suitable for application in ultra-deep hydrodesulfurization, denitrogenation, and aromatic removal reactions of diesel fractions. Implementation

[0045] 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.

[0046] 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).

[0047] In this invention, wt% is the mass fraction and v% is the volume fraction.

[0048] 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).

[0049] 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.

[0050] In the present application, the method for measuring the average pore diameter of different layers from the outer surface layer to the center core of the catalyst particles is as follows: first, the pore volume, specific surface area and average pore diameter of the sample are measured by low-temperature nitrogen adsorption method (BET), then a certain amount of sample is placed in a catalyst attrition tester, and a certain amount of quartz sand is added to increase the attrition rate. When the particle size of the sample is reduced to a certain extent after grinding, the weight loss of the sample is measured and the pore structure is measured again. According to 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 ground part can be calculated. At the same time, 20-80 samples are measured to calculate the average pore diameter. Thus, the average pore diameters of different layers from the outer surface layer to the center core are determined. Example 1

[0051] Ammonium metatungstate, ammonium molybdate and aluminum chloride were added into dissolving tank 1 containing deionized water to prepare a W, Mo and Al containing solution, in which the concentration of W (as WO3) was 60 g / L, the concentration of Mo (as MoO3) was 40 g / L and the concentration of Al (as Al2O3) was 26.6 g / L. Nickel chloride was added into dissolving tank 2 containing deionized water to prepare a Ni containing solution, in which the concentration of Ni (as NiO) was 48 g / L. The Al in the sodium aluminate solution accounted for 30% of the total Al (as Al2O3) in the obtained hydrorefining catalyst, and the solution was divided into four equal parts by volume. Deionized water, and castor oil phosphate in a molar ratio of 0.8 to the total number of Al atoms in the W, Mo and Al solution were added into the reaction tank. CO2 gas with a concentration of 55 vol% was bubbled into the solution in the reaction tank at a flow rate of 65 ml / min. The W, Mo and Al containing solution and a sodium hydroxide solution (10% by weight) were added into the reaction tank to perform a gelation reaction, the pH value of the reaction was controlled at 5.3, the reaction temperature was 60°C, and the reaction time was 0.5 h. Then, the Ni containing solution and a sodium hydroxide solution (10% by weight) were added into the reaction slurry simultaneously, the reaction temperature was not changed, the reaction time was 1.0 h, and the pH value of the reaction was controlled at 8.7 at the end of the reaction. The CO2 bubbling was stopped at the end of the reaction, and a precipitate slurry containing nickel, molybdenum, tungsten, aluminum and phosphorus was obtained. The obtained slurry was aged, the aging temperature was 76°C, and the pH value was controlled at 13.1 by adding the first part of the sodium aluminate solution at the beginning of the aging. The aging time was 0.2 h, then the pH value was controlled at 9.5, the aging time was 0.3 h, then the pH value was controlled at 5.5, the aging time was 0.2 h, and the above process was repeated four times to complete the aging. The aged slurry was filtered, the filter cake was dried at 100°C for 8 h, and then was rolled and extruded into strips. The strips were washed with deionized water at room temperature until neutral. Then the wet strips were dried by the following steps: the material was first dried at 80°C for 6.0 h, then deionized water was sprayed on the dried material, and the drying process was repeated five times. The volume ratio of the first spraying of deionized water to the dried material was 2:1, the drying temperature was 180°C, and the drying time was 2.2 h. The volume ratio of the second spraying of deionized water to the dried material was 1.4:1, the drying temperature was 190°C, and the drying time was 2.0 h. The volume ratio of the third spraying of deionized water to the dried material was 1:1, the drying temperature was 180°C, and the drying time was 2.0 h. The volume ratio of the fourth spraying of deionized water to the dried material was 1:1.8, the drying temperature was 180°C, and the drying time was 2.0 h. The volume ratio of the fifth spraying of deionized water to the dried material was 1:2.3, the drying temperature was 220°C, and the drying time was 2.0 h. The dried material was calcined at 530°C for 5 h to obtain catalyst A. The composition and main properties of the catalyst are shown in Table 1. Example 2

[0052] Ammonium metatungstate, ammonium molybdate and aluminum chloride were added into dissolving tank 1 containing deionized water to prepare a W, Mo and Al containing solution, in which the concentration of W (as WO3) was 44 g / L, the concentration of Mo (as MoO3) was 46 g / L and the concentration of Al (as Al2O3) was 24.5 g / L. Nickel chloride was added into dissolving tank 2 containing deionized water to prepare a mixed Ni containing solution, in which the concentration of Ni (as NiO) was 60 g / L. Sodium alumininate solution was prepared with Al accounting for 28% of Al (as Al2O3) in the obtained hydrorefining catalyst, and was divided into 6 equal parts by volume. Deionized water and lauryl ether phosphoric acid ester (MOA-9P) with a molar ratio of 0.9 to the total number of Al atoms in the W, Mo and Al containing solution were added into the reaction tank. CO2 gas with a concentration of 50 vol% was bubbled into the solution in the reaction tank at a flow rate of 60 ml / min. The W, Mo and Al containing solution and sodium hydroxide solution (12 wt%) were added into the reaction tank to carry out gelation reaction, and the pH value was controlled at 5.8 and the reaction temperature was 55°C. After 0.7 hours of reaction, the Ni containing solution and sodium hydroxide solution (12 wt%) were added into the reaction slurry simultaneously, and the reaction temperature was not changed. The reaction time was 1.2 hours, and the pH value was controlled at 9.0 at the end of the reaction. A precipitate slurry containing Ni, Mo, W, Al and P was obtained. The CO2 bubbling was stopped at the end of the reaction, and the obtained slurry was aged. The aging temperature was 80°C. At the beginning of the aging, one part of the sodium alumininate solution was added to control the pH value at 12.5. After 0.2 hours of aging, the pH value was controlled at 8.9. After 0.2 hours of aging, the pH value was controlled at 5.2. After 0.15 hours of aging, the above operation was repeated 6 times, and the aging was finished. The aged slurry was filtered, and the filter cake was dried at 90°C for 10 hours. The dried filter cake was crushed and extruded into strips. The strips were washed with deionized water at room temperature until neutral. Then the wet strips were dried by the following steps: the material was dried at 80°C for 6.5 hours. The dried material was evenly sprayed with deionized water, and then dried. The above operation was repeated 6 times. The volume ratio of the first spraying of deionized water to the dried material was 1.8:1, the drying temperature was 180°C, and the drying time was 2.0 hours. The volume ratio of the second spraying of deionized water to the dried material was 1.3:1, the drying temperature was 170°C, and the drying time was 1.8 hours. The volume ratio of the third spraying of deionized water to the dried material was 1.0:1, the drying temperature was 190°C, and the drying time was 1.8 hours. The volume ratio of the fourth spraying of deionized water to the dried material was 1:1.4, the drying temperature was 180°C, and the drying time was 1.7 hours. The volume ratio of the fifth spraying of deionized water to the dried material was 1:1.8, the drying temperature was 190°C, and the drying time was 1.6 hours. The volume ratio of the sixth spraying of deionized water to the dried material was 1:2.2, the drying temperature was 180°C, and the drying time was 2 hours.The washed wet strip was dried at 80°C for 12.0 hours. The dried material was calcined at 540°C for 6 hours to obtain catalyst B. The catalyst composition and main properties are shown in Table 1. Example 3

[0053] Ammonium metatungstate, ammonium molybdate and aluminum chloride were added to dissolving tank 1 containing deionized water to prepare a W, Mo, Al-containing solution, in which the concentration of W (as WO3) was 40 g / L, the concentration of Mo (as MoO3) was 36 g / L, and the concentration of Al (as Al2O3) was 21.8 g / L. Nickel chloride was added to dissolving tank 2 containing deionized water to prepare a Ni-containing solution, in which the concentration of Ni (as NiO) was 72 g / L. Sodium metaluminate solution was prepared to contain 32% of Al (as Al2O3) in the obtained hydrofining catalyst, and was divided into 5 equal parts by volume. Deionized water and alkylphenol ether phosphoric acid ester (TXP-4) in a molar ratio of 1.0 to the total number of Al atoms in the W, Mo, Al-containing solution were added to the reaction tank. CO2 gas with a concentration of 55 vol% was bubbled into the solution in the reaction tank at a flow rate of 80 ml / min. The W, Mo, Al-containing solution and sodium hydroxide solution (concentration of 11%) were added to the reaction tank to perform a gelation reaction, the pH value of the reaction was controlled at 5.2, the reaction temperature was 65°C, and the reaction time was 0.9 h. Then the Ni-containing solution and ammonia water (concentration of 11%) were added to the reaction slurry simultaneously, the reaction temperature was not changed, and the reaction time was 1.2 h. The pH value of the reaction was controlled at 9.0 at the end of the reaction, the CO2 bubbling was stopped, and a precipitate slurry containing nickel, molybdenum, tungsten, aluminum and phosphorus was obtained. The obtained slurry was aged, the aging temperature was 85°C, and the pH value was controlled at 13.2 by adding the first part of sodium metaluminate solution. The aging time was 0.15 h, then the pH value was controlled at 9.3, the aging time was 0.15 h, then the pH value was controlled at 5.4, the aging time was 0.2 h, and the above process was repeated 5 times to complete the aging. The aged slurry was filtered, the filter cake was dried at 90°C for 9 h, was rolled and was extruded into a strip. The strip was washed with deionized water at room temperature until neutral. Then the wet strip was dried by the following steps: the material was first dried at 82°C for 6.9 h, then was evenly sprayed with deionized water, and then was dried, and the above process was repeated 5 times. The volume ratio of the first spraying of deionized water to the dried material was 1.8:1, the drying temperature was 190°C, and the drying time was 2.2 h. The volume ratio of the second spraying of deionized water to the dried material was 1.1:1, the drying temperature was 170°C, and the drying time was 2.0 h. The volume ratio of the third spraying of deionized water to the dried material was 1:1.2, the drying temperature was 180°C, and the drying time was 1.8 h. The volume ratio of the fourth spraying of deionized water to the dried material was 1:1.7, the drying temperature was 180°C, and the drying time was 1.9 h. The volume ratio of the fifth spraying of deionized water to the dried material was 1:2.2, the drying temperature was 190°C, and the drying time was 1.8 h. The dried material was calcined at 520°C for 5 h to obtain catalyst C. The composition and main properties of the catalyst are shown in Table 1. Example 4

[0054] Ammonium metatungstate, ammonium molybdate and aluminum chloride were added into dissolving tank 1 containing deionized water to prepare a W, Mo and Al containing solution, in which the concentration of W (as WO3) was 52 g / L, the concentration of Mo (as MoO3) was 36 g / L and the concentration of Al (as Al2O3) was 27.4 g / L. Nickel chloride was added into dissolving tank 2 containing deionized water to prepare a Ni containing solution, in which the concentration of Ni (as NiO) was 56 g / L. The Al in the sodium aluminate solution accounted for 35% of the total Al (as Al2O3) in the obtained hydrofining catalyst, and the solution was divided into 6 equal parts by volume. Isomeric tridecanol ether phosphonate (E-1310P) was added into the reaction tank in a molar ratio of 0.7 to the total number of Al atoms in the W, Mo and Al solution. The solution in the reaction tank was bubbled with CO2 gas with a concentration of 55 vol% at a flow rate of 90 ml / min. The W, Mo and Al containing solution and ammonia water (10% by weight) were added into the reaction tank to perform a gelation reaction, the pH value of the reaction was controlled at 5.7, the reaction temperature was 72°C, and the reaction time was 0.6 hours. Then the Ni containing solution and ammonia water (13% by weight) were added into the reaction slurry simultaneously, the reaction temperature was not changed, and the reaction time was 1.2 hours. The pH value of the reaction was controlled at 10.0 at the end of the reaction. The CO2 bubbling was stopped at the end of the reaction, and a precipitate slurry containing nickel, molybdenum, tungsten, aluminum and phosphorus was obtained. The obtained slurry was aged, the aging temperature was 78°C. At the beginning of the aging, one part of the sodium aluminate solution was added to control the pH value at 12.4. The aging time was 0.15 hours. Then the pH value was controlled at 9.1 after the aging time of 0.25 hours. Then the pH value was controlled at 5.1 after the aging time of 0.2 hours. The above operation was repeated 6 times, and the aging was finished. The aged slurry was filtered, the filter cake was dried at 90°C for 11 hours, and then was rolled and extruded into strips. The strips were washed with deionized water at room temperature until neutral. Then the wet strips were dried by the following steps: the material was first dried at 80°C for 7.2 hours. The dried material was evenly sprayed with deionized water, and then was dried. The above process of evenly spraying deionized water and drying was repeated 5 times. The volume ratio of the first spraying of deionized water to the dried material was 1.9:1, the drying temperature was 190°C, and the drying time was 2.2 hours. The volume ratio of the second spraying of deionized water to the dried material was 1.3:1, the drying temperature was 200°C, and the drying time was 2.0 hours. The volume ratio of the third spraying of deionized water to the dried material was 1:1.3, the drying temperature was 180°C, and the drying time was 1.8 hours. The volume ratio of the fourth spraying of deionized water to the dried material was 1:1.9, the drying temperature was 180°C, and the drying time was 2.2 hours. The volume ratio of the fifth spraying of deionized water to the dried material was 1:2.3, the drying temperature was 170°C, and the drying time was 2.0 hours. The dried material was calcined at 530°C for 5 hours to obtain catalyst D. The composition and main properties of the catalyst are shown in Table 1.

[0055] Comparative Example 1

[0056] Reference agent E was prepared with the same catalyst composition as that of Example 1 of the present application, and the specific process was as follows:

[0057] Ammonium metatungstate, nickel chloride, ammonium molybdate and aluminum chloride were added into a dissolving tank 1 containing deionized water to prepare a mixed solution A, in which the weight concentration of W was 60 g / L as WO3, the weight concentration of Mo was 40 g / L as MoO3, the weight concentration of Ni was 48 g / L as NiO, and the weight concentration of Al was 52 g / L as Al2O3. Deionized water was added into a reaction tank, and the mixed solution A and a sodium hydroxide solution (10% by weight) were added into the reaction tank in parallel flow to carry out a gelation reaction, the reaction pH value was controlled at 7.8, the reaction temperature was 60°C, the reaction time was 1.5 hours, a precipitate slurry containing nickel, molybdenum, tungsten and aluminum was generated, the obtained slurry was aged, the aging temperature was 80°C, the pH value during aging was 8.5, the aging time was 2.8 hours, and the aging was ended. The aged slurry was filtered, the filter cake was dried at 100°C for 8 hours, was rolled and was extruded into a strip. The wet strip after washing was washed with deionized water at room temperature until neutral. Then the washed wet strip was dried at 100°C for 10 hours. The dried material was calcined at 530°C for 5 hours to obtain catalyst E. The catalyst composition and main properties are shown in Table 1.

[0058] Comparative Example 2

[0059] Reference agent F was prepared with the same catalyst composition as that of Example 1 of the present application according to the preparation method disclosed in CN102451703A, and the specific process was as follows:

[0060] Deionized water was added into dissolving tank 1, and then nickel chloride and ammonium metatungstate were added to dissolve and prepare mixed working solution A. The weight concentration of W in the form of WO3 in mixed solution A was 60 g / L, and the weight concentration of Ni in the form of NiO was 48 g / L. Water was added into dissolving tank 2, and then sodium aluminate was added to dissolve and prepare alkaline solution B. The weight concentration of Al in the form of Al2O3 in alkaline solution B was 52 g / L. Deionized water was added into a reaction tank, and the temperature was increased to 60 ℃. Under stirring, solution A, solution B and CO2 were added into the reaction tank to form gel, the concentration of CO2 was 40 vol%, the gel forming temperature was 60 ℃, the gel forming time was 1.5 hours, and the pH value of the gel slurry was 7.8. The total amount of CO2 gas added during the gel forming process was in a molar ratio of 3.5 to Al2O3 in the alkaline solution, the aging temperature was 80 ℃, the pH value during aging was 8.5, and the aging time after gel forming was 2.8 hours. Then, filtration was performed, 600 ml of pure water and 40.3 g of molybdenum trioxide were added into the filter cake, and the mixture was uniformly stirred and slushed, followed by filtration. The filter cake was dried at 100 ℃ for 8 hours, was rolled and was extruded into a strip. The wet strip was washed with deionized water at room temperature until neutral. Then, the washed wet strip was dried at 100 ℃ for 10 hours. The dried material was calcined at 530 ℃ for 5 hours to obtain catalyst F. The catalyst composition and main properties are shown in Table 1.

[0061] Comparative Example 3

[0062] According to the preparation method disclosed in CN106179380A, reference agent G with the same catalyst composition as that of the catalyst of Example 1 of the present application was prepared, and the specific process was as follows:

[0063] A mixed solution A was prepared by dissolving nickel chloride and aluminum chloride solution in deionized water, in which the weight concentration of NiO was 48 g / L and the weight concentration of Al2O3 was 26 g / L. A mixed solution B was prepared by dissolving ammonium metatungstate, ammonium molybdate and aluminum chloride solution in deionized water, in which the weight concentration of WO3 was 60 g / L, the weight concentration of MoO3 was 40 g / L, and the weight concentration of Al2O3 was 26 g / L. A 10% (by weight) sodium hydroxide solution was added to solution A under stirring, the gelation temperature was maintained at 60°C, the pH value was controlled at 7.8 at the end, and the gelation time was controlled at 60 minutes, to generate a slurry I containing nickel and aluminum precipitates. Deionized water was added to a reaction tank, and a 10% (by weight) sodium hydroxide solution and solution B were added to the reaction tank in parallel flow, the gelation temperature was maintained at 60°C, the pH value was controlled at 7.8 during the parallel flow gelation reaction process, and the gelation time was controlled at 60 minutes, to generate a slurry II containing tungsten, molybdenum and aluminum precipitates. The two kinds of slurry containing precipitates were mixed and aged, the aging time was 2.8 hours, the aging temperature was 80°C, and the pH value was controlled at 8.5, then filtration was performed, the filter cake was subjected to hydrothermal treatment under water vapor containing urea, the molar ratio of urea to total active metal atoms was 7:1, the temperature was 250°C, the pressure was 4.0 MPa, the treatment time was 3 hours, the filter cake was dried at 100°C for 8 hours, was rolled and was extruded into a strip. Washing with deionized water was performed at room temperature until neutral, then drying was performed at 100°C for 10 hours, and calcination was performed at 530°C for 5 hours, to obtain a catalyst G. The catalyst composition, pore distribution and main properties are shown in Table 1.

[0064] Comparative Example 4

[0065] According to the preparation method disclosed in CN106513006A, a reference agent H with the same catalyst composition as the catalyst of Example 1 of the present application was prepared, and the specific process was as follows:

[0066] The basic nickel carbonate was 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 1 h at constant temperature, the ultrasonic frequency was reduced to 20 kHz and the temperature of the system was increased to 120 °C. Ammonium molybdate and polyvinylpyrrolidone were added, followed by the dropwise addition of 10 ml of 25 wt% ammonia. The system was held at constant temperature for 2 h, after which the ultrasonic was turned off and stirring was turned on at 300 rpm. Ammonium metatungstate was added, followed by the addition of citric acid to bring the pH of the system to 4.2. The system was held at constant temperature for 2 h, after which the heating was turned off and the system was allowed to cool to room temperature. The slurry was collected and spray dried at an inlet temperature of about 200 °C and an outlet temperature of about 100 °C. The dried powder was calcined in a muffle furnace at 330 °C for 3 h to obtain the active component powder. The active component powder was mixed with 40 wt% of a dry gel of aluminum hydroxide and 10% of dilute nitric acid solution to obtain a dough, which was extruded into a 1.5 mm diameter strip. 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 composition and main properties of the catalyst are shown in Table 1.

[0067] Comparative Example 5

[0068] Reference agent I was prepared as in Example 1, but the entire Al-containing solution was added in one portion during the aging of the precipitate slurry containing nickel, molybdenum, tungsten and aluminum. The aging pH was a fixed value. The preparation process is as follows:

[0069] Ammonium metatungstate, ammonium molybdate and aluminum chloride were added into dissolving tank 1 containing deionized water to prepare a W, Mo, Al-containing solution, in which the weight concentration of W as WO3 was 60 g / L, the weight concentration of Mo as MoO3 was 40 g / L, and the weight concentration of Al as Al2O3 was 26.6 g / L. Nickel chloride was added into dissolving tank 2 containing deionized water to prepare a Ni-containing solution, in which the weight concentration of Ni as NiO was 48 g / L. The Al in the sodium aluminate solution accounted for 30% of the total Al (as Al2O3) in the obtained hydrorefining catalyst. Deionized water and castor oil phosphate having a molar ratio of 0.8 to the total number of Al atoms in the W, Mo, Al-containing solution were added into the reaction tank. The CO2 gas having a concentration of 55% was introduced into the solution in the reaction tank at a flow rate of 65 ml / min. The W, Mo, Al-containing solution and sodium hydroxide solution (10% by weight) were added into the reaction tank to perform a gelation reaction, the pH value was controlled at 5.3, the reaction temperature was 60°C, and the reaction time was 0.5 h. Then, the Ni-containing solution and sodium hydroxide solution (10% by weight) were added into the reaction slurry at the same time, the reaction temperature was not changed, the reaction time was 1.0 h, and the pH value was controlled at 8.7 at the end of the reaction. A precipitate slurry containing nickel, molybdenum, tungsten, aluminum and phosphorus was obtained, and the introduction of CO2 gas was stopped. The obtained slurry was aged, the total sodium aluminate solution was added at the beginning of the aging, the aging temperature was 76°C, the pH value was controlled at 8.5 during the aging, and the aging time was 2.8 h. The aged slurry was filtered, the filter cake was dried at 100°C for 8 h, was rolled and was extruded into a strip. The wet strip was washed with deionized water at room temperature until neutral. Then, the washed wet strip was dried in the following steps: the material was first dried at 80°C for 6.0 h, the dried material was evenly sprayed with deionized water, and then was dried, the process of evenly spraying deionized water and drying was repeated 5 times, the volume ratio of the first spraying deionized water to the dried material was 2:1, the drying temperature was 180°C, and the drying time was 2.2 h, the volume ratio of the second spraying deionized water to the dried material was 1.4:1, the drying temperature was 190°C, and the drying time was 2.2 h, the volume ratio of the third spraying deionized water to the dried material was 1:1, the drying temperature was 180°C, and the drying time was 2.0 h, the volume ratio of the fourth spraying deionized water to the dried material was 1:1.8, the drying temperature was 180°C, and the drying time was 2.0 h, and the volume ratio of the fifth spraying deionized water to the dried material was 1:2.3, the drying temperature was 260°C, and the drying time was 2.0 h. The dried material was calcined at 530°C for 5 h to obtain catalyst I. The catalyst composition and main properties are shown in Table 1.

[0070] Comparative Example 6

[0071] The same procedure as in Example 1 was followed to prepare Reference Example J, except that the second drying of the washed shaped product was performed under the first drying conditions (normal drying conditions). The procedure was as follows:

[0072] Ammonium metatungstate, ammonium molybdate and aluminum chloride were added to a dissolving tank 1 containing deionized water to prepare a W, Mo, Al-containing solution, the W concentration of which was 60 g / L as WO3, the Mo concentration of which was 40 g / L as MoO3, and the Al concentration of which was 26.6 g / L as Al2O3. Nickel chloride was added to a dissolving tank 2 containing deionized water to prepare a Ni-containing solution, the Ni concentration of which was 48 g / L as NiO. Sodium metaaluminate solution was prepared so that Al accounted for 30% of the total Al (as Al2O3) in the resulting hydrorefining catalyst, and was divided into four equal parts by volume. Deionized water, and a castor oil phosphoric acid ester in a molar ratio of 0.8 to the total number of Al atoms in the W, Mo, Al-containing solution were added to the reaction tank. A CO2 gas having a concentration of 55 vol% was bubbled into the solution in the reaction tank at a flow rate of 65 ml / min. The W, Mo, Al-containing solution and a sodium hydroxide solution (10% by weight) were added to the reaction tank to perform a gelation reaction, the pH of the reaction was controlled at 5.3, and the reaction temperature was 60°C. After 0.5 hours of reaction, the Ni-containing solution and a sodium hydroxide solution (10% by weight) were added to the reaction slurry simultaneously, the reaction temperature was not changed, and the reaction time was 1.0 hour. The pH at the end of the reaction was controlled at 8.7, the CO2 bubbling was stopped at the end of the reaction, and a precipitate slurry containing Ni, Mo, W, Al, and P was obtained. The slurry was aged at a temperature of 76°C. The pH was controlled at 13.1 by adding one part of the sodium metaaluminate solution at the beginning of the aging, and the aging time was 0.2 hours. The pH was controlled at 9.5 after 0.3 hours of aging, and the aging time was 0.2 hours. The pH was controlled at 5.5 after another 0.2 hours of aging, and the aging time was 0.2 hours. The above procedure was repeated four times, and the aging was completed. The aged slurry was filtered, the filter cake was dried at 100°C for 8 hours, was crushed, and was extruded into a strip shape. The wet strip was washed with deionized water at room temperature until neutral. The washed wet strip was dried at 90°C for 8 hours, and the dried product was calcined at 530°C for 5 hours to obtain Catalyst J. The composition and main properties of the catalyst are shown in Table 1.

[0073] Comparative Example 7

[0074] The same procedure as in Example 1 was followed to prepare Reference Example K, except that only deionized water was added to the reaction tank, and no castor oil phosphoric acid ester was added. In addition, no CO2 gas was bubbled into the reaction tank during the reaction. The procedure was as follows:

[0075] Ammonium metatungstate, ammonium molybdate and aluminum chloride were added into dissolving tank 1 containing deionized water to prepare a W, Mo and Al containing solution, in which the concentration of W (as WO3) was 60 g / L, the concentration of Mo (as MoO3) was 40 g / L and the concentration of Al (as Al2O3) was 26.6 g / L. Nickel chloride was added into dissolving tank 2 containing deionized water to prepare a Ni containing solution, in which the concentration of Ni (as NiO) was 48 g / L. The Al in the sodium aluminate solution accounted for 30% of the total Al (as Al2O3) in the obtained hydrorefining catalyst, and the sodium aluminate solution was divided into four equal parts by volume. Deionized water was added into a reaction tank, and the W, Mo and Al containing solution and sodium hydroxide solution (10% by weight) were added into the reaction tank to perform a gelation reaction. The pH value of the reaction was controlled at 5.3, the reaction temperature was 60°C, and the reaction time was 0.5 h. Then, the Ni containing solution and sodium hydroxide solution (10% by weight) were added into the reaction slurry to perform a reaction. The reaction temperature was not changed, the reaction time was 1.0 h, and the pH value of the reaction was controlled at 8.7 at the end of the reaction. A precipitate slurry containing Ni, Mo, W and Al was obtained. The obtained slurry was aged. The aging temperature was 76°C. At the beginning of the aging, one part of the sodium aluminate solution was added to control the pH value at 13.1. The aging time was 0.2 h. Then, the pH value was controlled at 9.5, the aging time was 0.3 h. Then, the pH value was controlled at 5.5, the aging time was 0.2 h. The above operation was repeated four times, and the aging was completed. The aged slurry was filtered, the filter cake was dried at 100°C for 8 h, was rolled, and was extruded into a strip. The wet strip was washed with deionized water at room temperature until neutral. Then, the washed wet strip was dried by the following steps: the material was first dried at 80°C for 6.0 h, the dried material was evenly sprayed with deionized water, and then was dried. The above operation of evenly spraying deionized water and drying was repeated five times. The volume ratio of the sprayed deionized water to the dried material was 2:1 in the first spraying and drying, the drying temperature was 180°C, and the drying time was 2.2 h. The volume ratio of the sprayed deionized water to the dried material was 1.4:1 in the second spraying and drying, the drying temperature was 190°C, and the drying time was 2.2 h. The volume ratio of the sprayed deionized water to the dried material was 1:1 in the third spraying and drying, the drying temperature was 180°C, and the drying time was 2.0 h. The volume ratio of the sprayed deionized water to the dried material was 1:1.8 in the fourth spraying and drying, the drying temperature was 180°C, and the drying time was 2.0 h. The volume ratio of the sprayed deionized water to the dried material was 1:2.3 in the fifth spraying and drying, the drying temperature was 260°C, and the drying time was 2.0 h. The dried material was calcined at 530°C for 5 h to obtain catalyst K. The composition and main properties of the catalyst are shown in Table 1. Example 5

[0076] The present examples are catalyst activity evaluation experiments of the present application, and are compared with comparative catalysts. The present catalysts A, B, C, D and comparative catalysts E, F, G, H, I, J, K are respectively used in a 200 mL small hydrogenation device for comparative evaluation experiments. In order to further evaluate the ability of the catalysts to saturate aromatics, catalytic diesel oil with high aromatics content is selected as the test raw material, and the main properties of the raw material are shown in Table 4. The catalyst activity evaluation process conditions are: hydrogen partial pressure is 6.4 MPa, reaction temperature is 360 ℃, liquid hourly space velocity is 2.3 h -1 -1, hydrogen to oil volume ratio is 500:1, and the evaluation results are shown in Table 5. From Tables 1-3, it can be seen that, compared with the comparative catalysts, the present catalysts have smaller average particle size of oxide particles and uniform distribution, more surface active metals, and a stepped pore size distribution. From Table 4, it can be seen that the aromatics content of the raw material oil used in the catalyst activity evaluation is high, which will increase the difficulty of hydrogenation saturation, ultra-deep hydrodesulfurization and denitrification of the raw material oil. From the evaluation results in Tables 5-6, it can be seen that the present catalysts not only have excellent hydrodesulfurization activity and hydrodenitrogenation activity, but also have excellent hydrogenation saturation performance, effectively reducing the aromatics content of heavy distillate oil, and the polycyclic aromatic hydrocarbon content is reduced more obviously. The present catalysts have excellent hydrogenation saturation, hydrodesulfurization and hydrodenitrogenation performance when used for processing heavy distillate oil, especially for processing poor quality diesel oil fraction with high aromatics content and high processing difficulty, effectively reducing the polycyclic aromatic hydrocarbon content and improving the cetane number of diesel oil.

[0077] Table 1 Catalyst composition and properties prepared by examples and comparative examples

[0078] Catalyst No. A B C D E F NiO, wt% 24 30 36 28 24 24 WO3, wt% 30 22 20 26 30 30 MoO3, wt% 20 23 18 18 20 20 Al203, wt% balance balance balance balance balance balance P2O5, wt% 7 8 10 7 - - Specific surface area, m 2 / g]] 296 288 303 309 156 219 Pore volume, mL / g 0.432 0.420 0.444 0.456 0.225 0.258 Catalyst particle size, mm 1.87 1.98 2.88 2.30 1.87 1.86 Catalyst particle cross-section Catalyst different layer thickness, R is catalyst particle size Outer surface layer 0.30R 0.30R 0.31R 0.31R 0.31R 0.28R Intermediate layer 0.41R 0.39R 0.40R 0.41R 0.39R 0.42R Central core layer 0.29R 0.31R 0.29R 0.28R 0.30R 0.30R Outer surface layer average pore size, nm 14.2 13.7 14.6 14.9 4.1 4.4 Intermediate layer average pore size, nm 8.8 8.6 9.1 9.4 4.1 4.4 Central core average pore size, nm 6.1 5.9 6.2 6.3 4.1 4.4

[0079] Table 1 (continued)

[0080] Catalyst No. G H I J K NiO, wt% 24 24 24 24 24 WO3, wt% 30 30 30 30 30 MoO3, wt% 20 20 20 20 20 Al203, wt% balance balance balance balance balance P2O5, wt% - - 7 7 - Specific surface area, m 2 / g]] 230 245 264 249 285 Pore volume, mL / g 0.342 0.388 0.381 0.351 0.418 Catalyst particle size, mm 1.85 1.86 1.85 1.88 1.87 Catalyst particle cross-section Catalyst different layer thickness, R is catalyst particle size Outer surface layer 0.31R 0.30R 0.29R 0.30R 0.29R Intermediate layer 0.40R 0.41R 0.40R 0.41R 0.41R Central core layer 0.29R 0.29R 0.31R 0.29R 0.30R Outer surface layer average pore size, nm 4.7 4.0 12.5 5.1 13.7 Intermediate layer average pore size, nm 4.7 4.0 7.8 5.1 8.5 Central core average pore size, nm 4.7 4.0 5.4 5.1 5.8

[0081] Table 2 Weight content ratio of active metal oxides in catalyst surface phase and bulk phase

[0082] Catalyst No. A B C D Table phase I W+Ni Bulk phase I W+Ni ]]> 4.75 4.66 4.96 4.89 Table phase I Mo Ni Bulk phase I Mo Ni ]]> ​​ 3.52 3.70 3.91 3.82

[0083] Table 2 (continued)

[0084] Catalyst No. E F G H I J K Table phase I W+Ni Bulk phase I W+Ni ]]> 0.98 1.16 1.19 1.29 3.09 3.54 3.97 Table phase I Mo Ni Bulk phase I Mo Ni ​​​ 1.06 1.05 0.99 0.92 2.08 2.62 2.99

[0085] Table 3 Average particle size and particle size distribution of oxide particles of catalysts obtained in each example

[0086] Catalyst No. A B C D E F Oxide particle average size, nm 9.8 10.5 9.6 10.1 26.5 28.9 Oxide particle size distribution, % Particle size less than 8 nm 9.01 8.45 9.69 8.76 2.36 2.03 Particle size 8 nm - 13 nm 80.68 79.61 81.45 79.71 10.98 8.56 Particle size greater than 13 nm 10.31 11.94 8.86 11.53 86.66 89.41

[0087] Table 3 (continued) Average particle size and particle size distribution of oxide particles of catalysts obtained in each example

[0088] Catalyst No. G H I J K Oxide particle average size, nm 28.6 22.3 18.9 10.9 20.5 Oxide particle size distribution, % Particle size less than 8 nm 2.17 3.18 16.44 8.03 2.44 Particle size 8 nm - 13 nm 8.81 11.61 30.37 79.13 17.21 Particle size greater than 13 nm 90.02 85.21 53.19 12.84 80.35

[0089] Table 4 Main properties of feed oils

[0090] Item Analysis result Density (20°C), g / cm 3 ]]> 0.9291 Distillation range, °C 162-380 S, pg / g 14650 N, pg / g 842 Aromatics, wt% 70.6 Polycyclic aromatics, wt% 45.3 Cetane number ＜24

[0091] Table 5 Results of catalyst activity evaluation

[0092] Catalyst No. A B C D E F Density of the produced oil (20°C), g / cm 3 ]]> 0.8683 0.8685 0.8680 0.8678 0.8862 0.8832 Distillation range, °C 164-367 166-368 163-367 162-366 179-377 180-376 S, pg / g 8.4 8.8 7.8 7.1 286.6 264.3 N, pg / g 4.4 4.6 4.2 3.9 89.5 80.1 Aromatics, wt% 34.4 34.6 34.2 33.9 49.8 49.1 Polycyclic aromatics, wt% 4.5 4.7 4.3 4.1 18.5 17.1 Cetane number 39.3 39.0 39.6 39.8 26.8 26.0

[0093] Table 5 (continued)

[0094] Catalyst No. G H I J K Density of the produced oil (20°C), g / cm 3 ]] 0.8831 0.8904 0.8742 0.8758 0.8705 Distillation range, °C 175-376 181-378 170-372 172-372 169-369 S, pg / g 226.3 321.4 47.6 60.3 15.8 N, pg / g 72.6 102.4 18.5 21.4 6.9 Aromatics, wt% 48.4 54.3 39.2 40.9 39.2 Polycyclic aromatics, wt% 15.1 19.8 9.1 10.7 9.3 Cetane number, 30.6 25.3 34.1 31.6 36.5

[0095] Table 6 Content of different nitrogen compounds in hydrofinished oils

[0096] Catalyst No. A B C D E F Nitrogen content in hydrofinished oil, pg / g 4.4 4.6 4.2 3.9 89.5 80.1 1-MCB, pg / g 2.4 2.6 2.4 2.3 39.6 36.2 1,8-BMCB, pg / g 1.2 1.1 1.0 0.9 28.8 25.4 1,4,8-TMCB, pg / g 0.8 0.9 0.8 0.7 21.1 18.5

[0097] Table 6 (continued)

[0098] Catalyst No. G H I J K Nitrogen content in hydrofinished oil, pg / g 72.6 102.4 18.5 21.4 6.9 1-MCB, pg / g 30.1 48.4 8.9 10.6 3.0 1,8-BMCB, pg / g 23.3 29.2 4.9 5.5 2.2 1,4,8-TMCB, pg / g 19.2 24.8 4.7 5.3 1.7

Claims

1. A process for the preparation of a phosphorus-containing hydrofinishing catalyst, characterized in that The method comprises the following steps: (1) adding deionized water and phosphate into a gelation reaction tank, continuously feeding CO2, and adding a W, Mo and Al-containing solution and a precipitant into the reaction tank to perform a first gelation reaction to obtain slurry I; (2) adding a Ni-containing solution and a precipitant into the slurry I obtained in step (1) to perform a second gelation reaction to obtain slurry II, continuously performing n times of aging on the slurry II, adjusting the pH value of the slurry II in each aging process by using 1 / n sodium metaaluminate solution, and filtering the slurry III obtained after the aging to obtain solid material; and (3) performing first drying, molding, washing, second drying and calcination on the solid material obtained in step (2) to obtain the phosphorus-containing hydrofining catalyst.

2. The method of claim 1, wherein: The phosphate in step (1) is one or more of octadecyl ether phosphate, alkylphenol ether phosphate, isomeric tridecanol ether phosphate, lauryl alcohol ether phosphate, castor oil phosphate, octadecyl phosphate and lauryl phosphate.

3. The method of claim 1, wherein: The molar ratio of the phosphate to Al in the W, Mo and Al-containing solution in step (1) is 0.2:1-2.0:

1.

4. The method of claim 1, wherein: The CO2 gas concentration in step (1) is 40v%-70v%, and the flow rate of the CO2 gas is 30-120 mL / min until the CO2 gas is stopped feeding after the gelation reaction is completed.

5. The method of claim 1, wherein: The W, Mo and Al-containing solution in step (1) contains W in an amount of 5-120 g / L as WO3, Mo in an amount of 5-110 g / L as MoO3 and Al in an amount of 2-90 g / L as Al2O3.

6. The method of claim 1, wherein: The first gelation reaction in step (1) is performed at a temperature of 30-95 ℃ for 0.1-1.0 hours.

7. The method of claim 1, wherein: The Ni-containing solution in step (2) contains Ni in an amount of 5-130 g / L as NiO, and the sodium metaaluminate solution contains Al in an amount of 5-70 g / L as Al2O3.

8. The method of claim 1, wherein: The precipitants in steps (1) and (2) are all alkaline precipitants, and are one or more of sodium carbonate, sodium bicarbonate, ammonia, sodium hydroxide, potassium hydroxide, potassium carbonate and potassium bicarbonate.

9. The method of claim 1, wherein: The second gelation reaction in step (2) is performed at a temperature of 30-95 ℃, and the pH value is controlled at 8.0-10.0 at the end of the reaction, and the reaction time is 0.5-2.5 hours.

10. The method of claim 1, wherein: The sodium metaaluminate solution in step (2) contains Al in an amount of 5-70 g / L as Al2O3, and the sodium metaaluminate solution is divided into 2-8 parts by volume according to the number of additions.

11. The method of claim 1, wherein: The slurry II in step (2) is continuously subjected to n times of three-stage decreasing pH aging, and each time, 1 / n sodium metaaluminate solution is used for adjusting the pH value in the first stage; wherein the specific process of each time of three-stage decreasing pH aging is as follows: the aging temperature of each stage is 60-98℃; in the first stage, the reaction slurry is dropped into 1 / n sodium metaaluminate solution for pH value adjustment, the pH value is controlled at 11.5-13.5, and the aging time is 0.05-0.5 hours; in the second stage, the pH value is adjusted to 8.0-10.0, and the aging time is 0.05-0.5 hours; in the third stage, the pH value is adjusted to 4.0-6.5, and the aging time is 0.05-0.5 hours; before the next three-stage decreasing pH aging, the pH value is adjusted back to 11.5-13.

5.

12. The method of claim 1, wherein: The first drying condition of step (3) is as follows: drying at 40-150℃ for 1-48 hours.

13. The method of claim 1, wherein: The volume ratio of the first water addition volume to the dried material volume is greater than 1:1, the volume ratio of the last water addition volume to the dried material volume is less than 1:1, and the volume ratio of the water addition volume to the dried material volume decreases successively with the increase of the drying times.

14. The method of claim 1, wherein: The calcination condition of step (3) is as follows: calcination at 350-650℃ for 1-24 hours.

15. A phosphorus-containing hydrofinishing catalyst prepared by the process of any one of claims 1 to 14. The catalyst is a bulk hydrogenation finishing catalyst, the total content of Ni, W and Mo in the form of oxides is 35%-95% based on the weight of the catalyst, the content of alumina is 5%-65%, and the total content of phosphorus in the form of P2O5 is 2%-17%; wherein the molar ratio of W / Mo is 1:13-10:1, and the molar ratio of Ni / (Mo+W) is 1:14-13:1; wherein 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 2.5:1-6.5:1, 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 2.3:1-5.5:1; the average particle size of the tungsten, molybdenum and nickel active metal oxide particles is 8-13 nm; the particle size distribution of the tungsten, molybdenum and nickel active oxide particles is as follows: the number of particles with a particle size less than 8 nm accounts for 3%-14% of the total number of particles, the number of particles with a particle size of 8 nm-13 nm accounts for 71%-88% of the total number of particles, and the number of particles with a particle size greater than 13 nm accounts for 5%-17% of the total number of particles.

16. The phosphorus-containing hydrofinishing catalyst of claim 15, wherein: The phosphorus-containing hydrogenation finishing catalyst is in the form of particles, the catalyst particles comprise an outer surface layer, an intermediate layer and a central core, and the average pore diameter decreases 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 10-18 nm, the average pore diameter of the intermediate layer is 7-10 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.

17. Use of a phosphorus-containing hydrofining catalyst prepared by the process of any one of claims 1 to 14 in the ultra-deep hydrodesulfurization, hydrodenitrogenation and hydrodearomatization of heavy diesel distillate fractions.