Process for the preparation of a hydrocracking catalyst

Abstract

The application discloses a preparation method of a hydrocracking catalyst, and comprises the following steps: (1) a solution containing a first hydrogenation active metal, an acidic component slurry and a mixed alkali solution are added into a reactor containing bottom water to perform a gelation reaction, so as to obtain a first gelation product; (2) a solution containing a second hydrogenation active metal, the first gelation product and the mixed alkali solution are added into a reactor containing bottom water and a phosphate compound to perform a gelation reaction, so as to obtain a second gelation product; (3) the second gelation product is continuously aged for N times, and the obtained solid material is prepared into a catalyst precursor, and the catalyst precursor is reduced to obtain the hydrocracking catalyst. According to the method, the active metal distribution in the catalyst is changed, the synergistic effect of the hydrogenation active component and the acidic component is enhanced, the utilization rate of the active metal of the catalyst is improved, and the requirements for isomerization performance and aromatic conversion capacity in the hydrocracking process for producing special oil and lubricating oil base oil are met.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of preparation of hydrogenation catalysts, and particularly relates to a preparation method of a hydrogenation cracking catalyst for treating heavy hydrocarbons. BACKGROUND

[0002] The hydrogenation cracking diesel fraction has the characteristics of water-white color, low impurity content, and high saturated hydrocarbon content, and can be used to produce various white oils, rust-proof oils, transformer oils, aluminum cold rolling oils, etc. The hydrogenation cracking tail oil fraction is suitable for being used as a lubricating oil base oil. The industrial white oil has a pour point index of-3~ -9℃ and an aromatic hydrocarbon mass content of not more than 5% according to different grades. The transformer oil has a pour point index in the range of-10℃~ -50℃ and a polycyclic aromatic hydrocarbon content of less than 3% according to different minimum cold operating temperatures in actual applications. According to the product indexes of special oils, the hydrogenation cracking catalyst needs to have both high isomerization performance and high aromatic conversion capacity, which requires that the acid component and the hydrogenation active metal component in the catalyst have a good synergistic effect.

[0003] At present, the acid component commonly used in hydrogenation cracking is a molecular sieve. The molecular sieve with good isomerization performance can generally meet the pour point index requirement of industrial white oil, but the conventional supported hydrogenation catalyst is limited by the pore structure of the carrier and the active metal loading (generally not more than 30wt%), and the hydrogenation activity is far from the aromatic conversion activity required for producing high-value special oil products.

[0004] Phosphide catalysts, as a new type of hydrogenation catalyst, have attracted great attention from many research institutions due to their noble metal-like characteristics and excellent hydrogenation performance. For example, CN102909055A discloses a preparation method of a metal phosphide hydrogenation cracking catalyst, which specifically comprises: first preparing a catalyst carrier containing a molecular sieve and an inorganic refractory oxide, impregnating the above carrier with an impregnation solution containing a VIB group metal compound, a VIII group metal compound and an inorganic phosphorus-containing compound, and then drying and hydrogen activating to obtain a hydrogenation cracking catalyst. CN102994147A discloses a method for producing middle distillate oil by heavy oil medium-pressure hydrogenation cracking. The hydrogenation cracking catalyst used in the method is prepared by impregnating a carrier in an aqueous solution containing a Ni hypophosphite, a transition metal salt and a complexing agent, and then drying and calcining to obtain a catalyst containing a Ni2P active phase. However, the supported phosphide hydrogenation catalyst still cannot meet the hydrogenation activity requirement.

[0005] CN111822022A discloses a preparation method of a phosphorus-containing hydrocracking catalyst, comprising the following contents: (1) preparing a solution A containing Ni and / or W, and preparing a mixed solution B containing Ni and / or W, Si and Al components; (2) performing a parallel flow gelation reaction on the solution A and a sodium metaaluminate alkaline solution to obtain a slurry I, aging and filtering; (3) uniformly mixing the filter cake obtained in the step (2), a suspension of molecular sieves and the solution B to obtain a mixture A, then adding an ammonia water solution B into the mixture A to perform a gelation reaction to obtain a slurry II, adding an organic phosphorus compound into the slurry II and aging; (4) drying, shaping and calcining the material obtained in the step (3), and then reducing to obtain a hydrocracking catalyst. The catalyst is a bulk catalyst, the metal content is high, the number of hydrogenation active centers is greatly increased, but the interaction with the acid component such as molecular sieves needs to be improved, and the phosphide content in the catalyst surface phase is small, which also affects the utilization rate of the active metal. SUMMARY

[0006] In view of the deficiencies in the prior art, the present application provides a preparation method of a hydrocracking catalyst. The catalyst is a phosphide bulk hydrocracking catalyst, the distribution of the hydrogenation active metal in the catalyst is changed, the synergistic effect of the hydrogenation active component and the acid component is enhanced, the utilization rate of the active metal of the catalyst is improved, and the requirements for isomerization performance and aromatic conversion capacity in the hydrocracking process for producing special oils and lubricating oil base oils are met.

[0007] The preparation method of the hydrocracking catalyst of the present application comprises the following contents:

[0008] (1) a solution containing a first hydrogenation active metal, an acid component slurry and a mixed alkali solution are added into a reactor containing bottom water in parallel flow to perform a gelation reaction, and a first gelation product is obtained;

[0009] (2) a solution containing a second hydrogenation active metal, the first gelation product and a mixed alkali solution are added into a reactor containing bottom water and a phosphate ester compound in parallel flow to perform a gelation reaction, and a second gelation product is obtained;

[0010] (3) the second gelation product is continuously aged for N times, and the solid-phase material obtained after the N times of aging is prepared into a phosphorus-containing hydrogenation active metal oxide catalyst precursor, and then reduced to obtain a hydrogenation cracking catalyst containing a hydrogenation active metal phosphide; wherein each aging process is as follows: the pH value is adjusted to 11.5-13.5 with 1 / N sodium metaaluminate solution, aged for 0.05-0.5 hours, then the pH value is adjusted to 8.5-10.5, aged for 0.05-0.5 hours, and finally the pH value is adjusted to 4.0-6.2, aged for 0.05-0.5 hours; wherein N is an integer of 2-8.

[0011] In the method, the first hydrogenation active metal in step (1) is W, the weight concentration of W in the form of WO3 in the aluminum salt solution containing the first hydrogenation active metal is 5-130 g / L, preferably 8-120 g / L, and the mass concentration of the aluminum salt in the form of Al2O3 is 5-120 g / L, preferably 10-115 g / L; wherein the W source commonly used in the preparation of the solution is ammonium metatungstate, and the aluminum salt is one or more of aluminum nitrate, aluminum sulfate, aluminum chloride and aluminum acetate.

[0012] In the method, the acid component slurry in step (1) is a uniform mixture of beta molecular sieve and deionized water, and the solid-liquid mass ratio is 1:3-1:9, preferably 1:2.5-1:8.5. The beta molecular sieve has the following properties: the molar ratio of silicon oxide to aluminum oxide is 30-85; the specific surface area is 350-780 m 2 / g, preferably 450-700 m 2 / g; the pore volume is 0.30-0.80 cm 3 / g, preferably 0.35-0.75 cm 3 / g; and the infrared acid acid amount is 0.10-0.55 mmol / g, preferably 0.18-0.50 mmol / g.

[0013] In the method, the mixed alkali solution in steps (1) and (2) is a mixture of ammonia and sodium phosphate solution, wherein the molar ratio of ammonia to sodium phosphate is 0.2:1-0.6:1; the concentration of ammonia water is 5wt%-10wt%, and the concentration of sodium phosphate solution is 8wt%-20wt%. The ratio and concentration of the mixed alkali solution in steps (1) and (2) are adjusted according to actual needs.

[0014] In the method, the gelation reaction conditions in step (1) are as follows: the reaction temperature is 30-95℃, preferably 40-95℃, the pH value is controlled between 5 and 6, and the reaction time is 0.1-1.0 hour.

[0015] In the method, the second hydrogenation active metal in step (2) is Ni, and the weight concentration of Ni in the form of NiO in the solution containing the second hydrogenation active metal is 10-120 g / L, preferably 12-115 g / L; when the solution is prepared, the nickel source is generally one or more of nickel sulfate, nickel nitrate and nickel chloride;

[0016] In the method, the gelation reaction conditions in step (2) are as follows: the reaction temperature is 30-95℃, preferably 40-95℃, the pH value is controlled between 8.0 and 12.0, and the reaction time is 0.5-2.5 hours.

[0017] In the method, the phosphate ester compound in step (2) is one or more of octadecyl ether phosphate (O-5P), alkyl phenol 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, lauryl phosphate, preferably one or more of alkyl phenol ether phosphate (TXP-4, TXP-10), isomeric tridecanol ether phosphate (E-1310P), lauryl alcohol ether phosphate (MOA-3P, MOA-9P), castor oil phosphate.

[0018] In the method, the molar ratio of the amount of the phosphate ester compound added in step (2) to Ni is 0.8:1 to 6.0:1, preferably 1.5:1 to 5.5:1.

[0019] In the method, the aging temperature in step (3) is 60 to 98℃, preferably 65 to 92℃.

[0020] In the method, the weight concentration of Al in the sodium metaaluminate solution in step (3) is 5 to 70 g / L, preferably 8 to 60 g / L, calculated as Al2O3. The sodium metaaluminate solution is divided into 2 to 8 parts by volume according to the number of additions, preferably equal parts by volume.

[0021] In the method, in addition to using the sodium metaaluminate solution when the pH value is adjusted to 11.5 to 13.5 during the aging process, the acid and base used to adjust the 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 needs of preparation.

[0022] In the method, the Al added by the sodium metaaluminate solution accounts for 5% to 55%, preferably 6% to 50%, of the total Al in the obtained hydrocracking catalyst, calculated as Al2O3.

[0023] In the method of the present application, the process for preparing the solid material in step (3) into a phosphide catalyst precursor is a common method in the art, and the general steps are drying, molding and washing, followed by drying, calcination; the 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 molding process, conventional molding aids such as one or more of a peptizing agent, an extrusion aid, etc. can be added as needed. 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 a substance that is beneficial to extrusion molding, such as one or more of sesbania powder, carbon black, graphite powder, citric acid, etc., and the amount of the extrusion aid is 1wt%-10wt% of the total material dry basis. Washing is generally done with deionized water or a solution containing decomposable salts (such as ammonium acetate, ammonium chloride, ammonium nitrate, etc.) until neutral. The shape of the catalyst can be sheet, spherical, cylindrical strip, and irregular strip (three-leaf clover, four-leaf clover) as needed, preferably cylindrical strip and irregular strip (three-leaf clover, four-leaf clover). The diameter of the catalyst can be 0.8-2.0mm thin strips and >2.5mm thick strips; the calcination conditions are as follows: calcination at 350-700°C for 1-24 hours, preferably calcination at 400-650°C for 2-12 hours.

[0024] In the method of the present application, the reduction process in step (3) is carried out in a hydrogen atmosphere, in the first stage, the temperature is raised at a rate of 3-10°C / min from room temperature to 300-550°C, and after constant temperature for 1-5 hours, in the second stage, the temperature is raised at a rate of 0.5-5°C / min to 600-750°C, and constant temperature for 2-8 hours, the temperature raising rate in the second stage is at least 1°C / min lower than that in the first stage, preferably at least 2°C / min lower. The purity of hydrogen is greater than 99v%; the hydrogen flow rate is 150-700mL / min, preferably 250-600mL / min.

[0025] In the method of the present application, to prevent the phosphide from reacting violently with air, the prepared hydrocracking catalyst sample is passivated before being exposed to air. For example, it can be first passivated with O2 / N2 passivation gas with an oxygen volume concentration of 0.5%-3% for 1-5 hours.

[0026] The application also provides a hydrocracking catalyst, wherein WP and Ni2P are 20wt%-68wt%, preferably 22wt%-65wt%, beta molecular sieve is 5wt%-25wt%, preferably 6wt%-16wt%, amorphous alumina is 15wt%-65wt%, preferably 18wt%-60wt%, the mass ratio of Ni2P in the surface phase to Ni2P in the bulk phase is 2.8:1-7.2:1, preferably 3.0:1-6.8:1, the mass ratio of WP in the surface phase to WP in the bulk phase is 2.3:1-6.3:1, preferably 2.5:1-5.8:1, the molar ratio of Ni / W of the catalyst is 0.1:1-13:1, preferably 0.2:1-11:1, and the average particle diameter of the transition metal phosphide is 4-8nm.

[0027] The specific surface area of the hydrocracking catalyst is 150-700m 2 / g, and the pore volume is 0.25-1.2mL / g.

[0028] The hydrocracking catalyst prepared by the method has high aromatic saturation reaction performance, high isomerization performance and high aromatic conversion capacity, and can be used in the process of producing special oil by hydrocracking, so that the aromatic content and pour point of the hydrocracking diesel oil fraction product can meet the requirements of 5# industrial grade white oil and high viscosity index lubricating oil base oil.

[0029] Compared with the prior art, the application has the following advantages:

[0030] 1. The first and second hydrogenation active metals are precipitated respectively, the specific adding sequence, corresponding pH value control and active metal precipitation sequence can obviously increase the content of the active metal in the surface phase.

[0031] 2、The present application swings pH value during aging and adds sodium metaaluminate solution in batches, dissolves amorphous oxide in oxide particles through pH value swing, re-modifies oxide particle size by adding sodium metaaluminate solution, controls oxide particle growth through multiple pH value swing, makes oxide particles more uniform, and the particles are small, exposes more active metal in the surface phase, at the same time, the aluminum introduced by sodium metaaluminate solution increases the surface hydroxyl, further enhances the adhesion of oxide, and is beneficial to the forming of bulk phase catalyst. DETAILED DESCRIPTION

[0032] In the present application, the specific surface area, pore volume and pore distribution are determined by low-temperature liquid nitrogen adsorption method, the mechanical strength is determined by side pressure method, and the diameter of transition metal phosphide particles is determined by TEM technology. In the present application, wt% is mass fraction, and v% is volume fraction.

[0033] The surface phase phosphide content of the catalyst is determined by X-ray photoelectron spectroscopy (XPS), and the bulk phase phosphide content of the catalyst is determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). First, the surface and bulk active metal contents of the transition metal oxide precursor of the catalyst of the present application are determined, and then converted into the transition metal phosphide content in the surface and bulk phases of the catalyst. In the present application, the properties of the β molecular sieve used are shown in Table 5. Example 1

[0034] Ammonium metatungstate, aluminum chloride solution were added into dissolving tank 1 containing deionized water to prepare a W, Al-containing solution, the W-containing solution had a W concentration of 40 g / L as WO3 and an Al concentration of 56 g / L as Al2O3. Nickel chloride was added into dissolving tank 2 containing deionized water to prepare a Ni-containing solution, the Ni-containing solution had a Ni concentration of 56 g / L as NiO. The Al in sodium aluminate solution accounted for 30% of the total Al (as Al2O3) in the obtained hydrocracking catalyst, and the sodium aluminate solution was divided into 5 equal parts by volume. The ammonia water and sodium phosphate solution had a molar ratio of ammonia to sodium phosphate of 0.5:1. Deionized water was added into reaction tank 1, and the ammonia water, sodium phosphate solution, beta molecular sieve slurry and W, Al-containing solution were added into the reaction tank to carry out a gelation reaction, the gelation temperature was kept at 60°C, the pH value was controlled at 5.4 during the concurrent gelation reaction, the gelation time was controlled at 0.7 hours, and a W, Al, P-containing precipitate slurry I was generated. In reaction tank 2, deionized water and castor oil phosphate were added, the molar ratio of castor oil phosphate to the total number of Ni atoms in the Ni-containing solution was 2.5. The W, Al, P-containing slurry I, Ni-containing solution and ammonia water and sodium phosphate solution were added concurrently, the molar ratio of ammonia to sodium phosphate in the ammonia water and sodium phosphate solution was 0.5:1, the reaction temperature was unchanged, the reaction time was 1.0 hours, the reaction pH value was controlled at 8.9, and a Ni, W, Al, P-containing precipitate slurry was generated. The obtained slurry was aged, the aging temperature was 76°C, during the aging, the pH value was first controlled at 13.0 by adding one part of the sodium aluminate solution, the aging time was 0.2 hours, then the aging pH value was controlled at 9.3, the aging time was 0.15 hours, then the pH value was controlled at 5.2, the aging time was 0.2 hours, and the above operation was repeated 5 times to end the aging. 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 until neutral at room temperature. Then the washed wet strip was dried at 80°C for 10 hours, and the dried material was calcined at 530°C for 4 hours to obtain a phosphide catalyst precursor A. The precursor A was heated to 440°C at a hydrogen flow rate of 300 mL / min and a temperature increasing rate of 6°C / min under a pure hydrogen atmosphere, was kept at 440°C for 4.5 hours, was heated to 680°C at a temperature increasing rate of 2.5°C / min, and was kept at 680°C for 4 hours. To prevent the phosphide from reacting violently with air due to oxidation, the catalyst sample was passivated with O2 / N2 passivation gas having an oxygen volume concentration of 1.5% for 3 hours before the catalyst sample was exposed to air to obtain a hydrocracking catalyst A. The catalyst composition and main physicochemical properties are shown in Table 1. Example 2

[0035] Ammonium metatungstate, aluminum chloride solution were added into dissolving tank 1 containing deionized water to prepare a W, Al-containing solution, the W-containing solution had a W concentration of 34 g / L as WO3 and an Al concentration of 60 g / L as Al2O3. Nickel chloride was added into dissolving tank 2 containing deionized water to prepare a Ni-containing solution, the Ni-containing solution had a Ni concentration of 66 g / L as NiO. The Al in sodium aluminate solution accounted for 25% of the total Al (as Al2O3) in the obtained hydrocracking catalyst, and the sodium aluminate solution was divided into 6 equal parts by volume. The ammonia water and sodium phosphate solution had a molar ratio of ammonia to sodium phosphate of 0.45:1. Deionized water was added into reaction tank 1, and the ammonia water, sodium phosphate solution, beta molecular sieve slurry and W, Al-containing solution were added into the reaction tank to carry out a gelation reaction, the gelation temperature was kept at 55°C, the pH value was controlled at 5.2 during the concurrent gelation reaction, the gelation time was controlled at 0.8 hours, and a W, Al, P-containing precipitate slurry I was generated. In reaction tank 2, deionized water and lauryl alcohol ether phosphate were added, the molar ratio of lauryl alcohol ether phosphate to the total number of Ni atoms in the Ni-containing solution was 2.9. The W, Al, P-containing slurry I, Ni-containing solution and ammonia water and sodium phosphate solution were added concurrently, the reaction temperature was unchanged, the reaction time was 1.1 hours, and the reaction pH value was controlled at 9.4, and a precipitate slurry containing nickel, tungsten, aluminum and phosphorus was generated. The obtained slurry was aged, the aging temperature was 80°C, the pH value was controlled at 13.2 by adding one part of sodium aluminate solution during the aging, the aging time was 0.15 hours, then the aging pH value was controlled at 9.5, the aging time was 0.15 hours, then the pH value was controlled at 5.0, the aging time was 0.15 hours, and the above operation was repeated 6 times, and the aging was ended. The aged slurry was filtered, the filter cake was dried at 90°C for 10 hours, was rolled and was extruded into a strip. The wet strip after washing was washed with deionized water until neutral at room temperature. Then the washed wet strip was dried at 80°C for 9 hours, and the dried material was calcined at 520°C for 5 hours to obtain a phosphide catalyst precursor B. The precursor B was heated from room temperature to 420°C at a heating rate of 5.5 ℃ / min under a pure hydrogen atmosphere, and was kept at 420°C for 4.8 hours. Then the temperature was increased to 690°C at a heating rate of 2.8 ℃ / min, and was kept at 690°C for 4.5 hours. In order to prevent the phosphide from reacting with air to cause severe oxidation, the catalyst sample was passivated with O2 / N2 passivation gas with an oxygen volume concentration of 1.8% for 3.5 hours before the catalyst sample was exposed to air to obtain a hydrocracking catalyst B. The catalyst composition and main physicochemical properties are shown in Table 1. Example 3

[0036] Ammonium metatungstate, aluminum chloride solution were added into dissolving tank 1 containing deionized water to prepare W, Al-containing solution, the weight concentration of W in the W, Al-containing solution was 30 g / L as WO3, and the weight concentration of Al was 52 g / L as Al2O3. Nickel chloride was added into dissolving tank 2 containing deionized water to prepare Ni-containing solution, the weight concentration of Ni in the Ni-containing solution was 66 g / L as NiO. The Al in sodium aluminate solution accounted for 35% of the total Al (as Al2O3) in the obtained hydrocracking catalyst, and the sodium aluminate solution was divided into 5 equal parts by volume. The molar ratio of ammonia to sodium phosphate in the ammonia solution and sodium phosphate solution was 0.35:1. Deionized water was added into reaction tank 1, and the ammonia solution, sodium phosphate solution, beta molecular sieve slurry and W, Al-containing solution were added into the reaction tank to carry out the gelation reaction, the gelation temperature was kept at 65 ℃, the pH value was controlled at 5.4 during the concurrent gelation reaction, the gelation time was controlled at 0.8 hours, and the W, Al, P-containing precipitate slurry I was generated. In reaction tank 2, deionized water and isomeric tridecanol ether phosphate (E-1310P) were added, and the molar ratio of isomeric tridecanol ether phosphate (E-1310P) to the total number of Ni atoms in the Ni-containing solution was 3.0. The W, Al, P-containing slurry I, Ni-containing solution and ammonia solution and sodium phosphate solution were added concurrently, the reaction temperature was unchanged, the reaction time was 1.2 hours, the reaction pH value was controlled at 9.4, and the nickel, tungsten, aluminum, phosphorus-containing precipitate slurry was generated. The obtained slurry was aged, the aging temperature was 83 ℃, during the aging, first, one part of the sodium aluminate solution was added to control the pH value to 12.7, the aging time was 0.15 hours, then the aging pH value was controlled at 9.3, the aging time was 0.2 hours, then the pH value was controlled to 4.8, the aging time was 0.15 hours, the above operation process was repeated 5 times, and the aging was ended. The aged slurry was filtered, the filter cake was dried at 110 ℃ 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 90 ℃ for 10 hours, and the dried material was calcined at 510 ℃ for 5 hours to obtain the phosphide catalyst precursor C. The precursor C was heated to 450 ℃ at a hydrogen flow rate of 400 mL / min and a temperature increasing rate of 7 ℃ / min from room temperature under a pure hydrogen atmosphere, was kept at 450 ℃ for 3.5 hours, was heated to 670 ℃ at a temperature increasing rate of 3.5 ℃ / min, and was kept at 670 ℃ for 5 hours. In order to prevent the phosphide from reacting with air to cause severe oxidation, the catalyst sample was passivated with O2 / N2 passivation gas with an oxygen volume concentration of 2.2% for 4 hours before the catalyst sample contacted with air to obtain the hydrocracking catalyst C. The catalyst composition and main physicochemical properties are shown in Table 1. Example 4

[0037] Ammonium metatungstate, aluminum chloride solution were added into dissolving tank 1 containing deionized water to prepare a W, Al-containing solution, the W-containing solution had a W concentration of 40 g / L as WO3, and an Al concentration of 57 g / L as Al2O3. Nickel chloride was added into dissolving tank 2 containing deionized water to prepare a Ni-containing solution, the Ni-containing solution had a Ni concentration of 52 g / L as NiO. The Al in the sodium aluminophosphate solution accounted for 32% of the total Al (as Al2O3) in the obtained hydrocracking catalyst, and the sodium aluminophosphate solution was divided into 7 equal parts by volume. The molar ratio of ammonia to sodium phosphate in the ammonia solution and the sodium phosphate solution was 0.43:1. Deionized water was added to reaction tank 1, and the ammonia solution, the sodium phosphate solution, the β molecular sieve slurry, and the W, Al-containing solution were added into the reaction tank to perform a gelation reaction, the gelation temperature was maintained at 69 ℃, the pH value was controlled at 5.6 during the concurrent gelation reaction, the gelation time was controlled at 0.8 hours, and a W, Al, P-containing precipitate slurry I was generated. In reaction tank 2, deionized water and isomeric tridecanol ether phosphate were added, and the molar ratio of isomeric tridecanol ether phosphate to the total number of Ni atoms in the Ni-containing solution was 3.3. The W, Al, P-containing slurry I, the Ni-containing solution, and the ammonia solution and the sodium phosphate solution were added concurrently, the reaction temperature was not changed, the reaction time was 1.0 hours, and the reaction pH value was controlled at 9.7, and a nickel, tungsten, aluminum, and phosphorus-containing precipitate slurry was generated. The obtained slurry was aged, the aging temperature was 85 ℃, and during the aging, the pH value was first controlled at 13.2 by adding one portion of the sodium aluminophosphate solution, the aging time was 0.2 hours, then the aging pH value was controlled at 9.0, the aging time was 0.15 hours, then the pH value was controlled at 5.6, the aging time was 0.2 hours, and the above operation was repeated 7 times, and the aging was completed. The aged slurry was filtered, the filter cake was dried at 90 ℃ for 12 hours, was rolled and pressed, 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 90 ℃ for 12 hours, and the dried material was calcined at 550 ℃ for 4 hours to obtain a phosphide catalyst precursor D. The precursor D was heated in a pure hydrogen atmosphere, the hydrogen flow rate was 410 mL / min, the heating rate was 6.5 ℃ / min, the temperature was increased from room temperature to 460 ℃, the temperature was kept constant for 4.3 hours, then the temperature was increased to 650 ℃ at a heating rate of 4.0 ℃ / min, and the temperature was kept constant for 4 hours. In order to prevent the phosphide from reacting violently with air, the catalyst sample was passivated with O2 / N2 passivation gas with an oxygen volume concentration of 2.0% for 3.8 hours before the catalyst sample was exposed to air, and a hydrocracking catalyst D was obtained. The catalyst composition and main physicochemical properties are shown in Table 1.

[0038] Comparative Example 1

[0039] Preparation of a hydrocracking catalyst E according to the method of CN111822035A Example 1

[0040] Nickel nitrate was added to a dissolving tank 1 containing deionized water, and a dilute water glass solution was added to prepare a mixed solution A. The weight concentration of Ni in the mixed solution A was 40 g / L as NiO, and the weight concentration of Si was 10 g / L as SiO2. Ammonium metatungstate was added to a dissolving tank 2 containing deionized water, and a dilute water glass solution was added to prepare a mixed solution B. The weight concentration of W in the mixed solution B was 38 g / L as WO3, and the weight concentration of Si was 15.5 g / L as SiO2. Deionized water was added to a reaction tank, and a sodium metaaluminate solution with a weight concentration of 20 g / L as Al2O3 and the mixed solution A were added to the reaction tank in parallel flow. The gelation temperature was maintained at 58°C, the pH value was controlled at 7.6 during the parallel flow gelation reaction, the gelation time was controlled at 1.0 hour, and slurry I was obtained. The obtained precipitate slurry I was aged under stirring at a stirring speed of 220 rpm, an aging temperature of 75°C, and an aging pH value of 7.2 for 0.6 hour. After the aging was completed, the mixed solution B, a sodium metaaluminate solution with a weight concentration of 15 g / L as Al2O3, and a β molecular sieve suspension were added to the slurry I in parallel flow. The gelation temperature was maintained at 58°C, the pH value was controlled at 8.7 during the parallel flow gelation reaction, and the gelation time was controlled at 2.8 hours. The precipitate slurry II was obtained, and the β molecular sieve was added in an amount of 10 wt% based on the total weight of the catalyst. The properties of the β molecular sieve are shown in Table 4. Diethylene triamine penta methylene phosphonic acid was added to the precipitate slurry II, and the molar ratio of diethylene triamine penta methylene phosphonic acid to the nickel transition metal in the catalyst was 4.5:1. The precipitate slurry II was aged under stirring at a stirring speed of 410 rpm, an aging temperature of 75°C, and an aging pH value of 9.0 for 3.7 hours. The obtained material was dried at 130°C for 12 hours, shaped, calcined at 530°C for 5 hours, and a phosphide catalyst precursor E was obtained. The precursor A was heated from room temperature to 450°C at a heating rate of 6°C / min in a pure hydrogen atmosphere at a hydrogen flow rate of 320 mL / min, kept at 450°C for 4.0 hours, heated to 630°C at a heating rate of 3.0°C / min, and kept at 630°C for 3 hours. To prevent the phosphide from reacting violently with air due to oxidation, the catalyst sample was passivated in a O2 / N2 passivation gas with an oxygen volume concentration of 1.1% for 1.3 hours before the catalyst sample was exposed to air, and a hydrocracking catalyst E was obtained. The weight of the nickel introduced through the mixed solution E accounted for 70% of the total weight of the nickel and tungsten in the hydrocracking catalyst E, and the weight of Al in the precipitate I accounted for 60% of the total weight of Al in the hydrocracking catalyst E. The catalyst composition and main physicochemical properties are shown in Table 1.

[0041] Comparative Example 2

[0042] The β molecular sieve slurry was added after the aging was completed, and a reference agent F was prepared according to Example 1.

[0043] Comparative Example 3

[0044] The same as Example 1, Reference G was prepared, all the sodium metaaluminate solution was added at the beginning of aging, and a fixed value was used for the aging pH value. The preparation process is as follows:

[0045] Ammonium metatungstate and aluminum chloride solution were added to a dissolving tank 1 containing deionized water to prepare a W and Al containing solution, the W and Al containing solution had a W concentration of 40 g / L as WO3 and an Al concentration of 80 g / L as Al2O3. Nickel chloride was added to a dissolving tank 2 containing deionized water to prepare a Ni containing solution, the Ni containing solution had a Ni concentration of 56 g / L as NiO. The Al in the sodium metaaluminate solution accounted for 30% of the total Al (as Al2O3) in the obtained hydrocracking catalyst, the molar ratio of ammonia to sodium phosphate in the ammonia water and sodium phosphate solution was 0.5:1, deionized water was added to a reaction tank 1, and the ammonia water, sodium phosphate solution, β molecular sieve slurry and W and Al containing solution were added to the reaction tank to carry out a gelation reaction, the gelation temperature was kept at 60°C, the pH value was controlled at 5.4 during the concurrent gelation reaction, the gelation time was controlled at 0.7 hours, and a W, Al and P containing precipitate slurry I was generated. In a reaction tank 2, deionized water and castor oil phosphate were added, the molar ratio of castor oil phosphate to the total number of Ni atoms in the Ni containing solution was 2.5. The W, Al and P containing slurry I, the Ni containing solution and the ammonia water and sodium phosphate solution were added concurrently, the reaction temperature was unchanged, the reaction time was 1.0 hours, the reaction pH value was controlled at 8.9, and a Ni, W, Al and P containing precipitate slurry was generated. The obtained slurry was aged, at the beginning of aging, all the sodium metaaluminate solution was added, the aging temperature was 76°C, the aging pH value was 8.0, the aging time was 2 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 until neutral at room temperature. Then the washed wet strip was dried at 80°C for 10 hours, the dried material was calcined at 530°C for 4 hours, and a phosphide catalyst precursor G was obtained. The precursor G was heated from room temperature to 440°C at a hydrogen flow rate of 300 mL / min and a heating rate of 6°C / min in a pure hydrogen atmosphere, was kept at 440°C for 4.5 hours, was heated to 680°C at a heating rate of 2.5°C / min, and was kept at 680°C for 4 hours. To prevent the phosphide from reacting violently with air due to oxidation, the catalyst sample was passivated with O2 / N2 passivation gas with an oxygen volume concentration of 1.5% for 3 hours before the catalyst sample contacted air, and a hydrocracking catalyst G was obtained. The catalyst composition and main physicochemical properties are shown in Table 1.

[0046] Comparative Example 4

[0047] The same as Example 1, Reference H was prepared using ammonia water as a precipitant.

[0048] Comparative Example 5

[0049] Example 1, using sodium phosphate solution as precipitant to prepare Reference Agent I.

[0050] Comparative Example 6

[0051] Example 1, the molar ratio of ammonia to sodium phosphate is 0.75:1, to prepare Reference Agent J. Example 5

[0052] This example is the catalyst activity evaluation experiment of the present application, and the catalysts of the comparative examples are compared. The catalysts A, B, C and D of the present application and the catalysts E, F, G, H, I and J of the comparative examples are respectively used in the 200 mL small hydrogenation device for comparison and evaluation test. The evaluation conditions are: total reaction pressure 15.7 MPa, hydrogen oil volume ratio 1200:1, liquid hourly space velocity 1.7 h -1 , reaction temperature 375℃, and the evaluation raw material is vacuum gas oil, the main properties of which are shown in Table 4, and the evaluation results are shown in Tables 5-6. As can be seen from Tables 1-2, the phosphide particles of the catalysts of the present application have smaller average particle size, more surface active metals and good dispersion, higher aromatic saturation performance, and good synergy between acidic components and hydrogenation components. The catalysts of the present application have high isomerization performance and high aromatic saturation performance in the treatment of heavy raw oil hydrocracking process, and can produce No. 5 industrial grade white oil and lubricating oil base oil. The catalysts of the comparative examples cannot have high isomerization performance and high aromatic saturation performance at the same time.

[0053] Table 1 Catalyst composition and properties prepared by examples and comparative examples

[0054] Catalyst No. A B C D E F Catalyst composition [Ni2P, wt%] 28 30 33 26 35 28 WP, wt% 20 17 15 20 15 20 SiO2, wt% 12 13 12 12 24 12 Al203, wt% 40 40 40 42 26 40 Catalyst properties Specific surface area, m 2 / g]] 424 415 430 434 424 417 Pore volume, mL / g 0.449 0.430 0.453 0.460 0.449 0.436 Pore distribution < 6 nm 7.86 8.94 7.15 6.43 31.45 7.70 6 nm ~ 10 nm 62.65 61.67 62.87 62.61 27.23 62.12 10 nm ~ 15 nm 16.71 16.95 16.99 17.25 30.23 17.53 > 15 nm 12.78 12.44 12.99 13.71 11.09 12.65 Average transition metal phosphide particle diameter, nm 6.2 6.4 6.0 6.1 7.0 6.7

[0055] Table 1 Catalyst composition and properties prepared by examples and comparative examples

[0056] Catalyst No. G H I J Catalyst composition [Ni2P, wt%] 28 28 28 28 WP, wt% 20 20 20 20 SiO2, wt% 12 12 12 12 Al203, wt% 40 40 40 40 Catalyst properties Specific surface area, m 2 / g]] 229 185 402 208 Pore volume, mL / g 0.359 0.289 0.422 0.327 Pore distribution < 6 nm 40.73 62.71 9.12 48.34 6 nm ~ 10 nm 37.12 20.13 62.43 29.42 10 nm ~ 15 nm 12.31 8.99 16.71 11.51 > 15 nm 9.84 8.17 11.74 10.73 Average transition metal phosphide particle diameter, nm 23.9 6.9 29.1 12.3

[0057] Table 2 Weight content ratio of catalyst surface phase and bulk phase active metal oxides

[0058] Catalyst No. A B C D E F Table phase I Ni2P Bulk phase I Ni2P ]]> 5.89 5.67 5.97 5.81 1.36 4.92 Table phase I WP Bulk phase I WP ]]> 4.93 4.69 4.89 4.74 1.19 3.91

[0059] Table 2 Weight content ratio of catalyst surface phase and bulk phase active metal oxides

[0060] Catalyst No. G H I J Table phase I Ni2P Bulk phase I Ni2P ]]> 2.13 1.48 2.67 2.03 Table phase I WP Bulk phase I WP ]]> 1.75 1.34 1.86 1.59

[0061] Table 3 Main properties of raw oil

[0062] Feed oil Middle East vacuum gas oil Density (20°C) / g-cm -3 ]] 0.9287 Distillation range, °C IBP / EBP 319 / 535 S, wt% 2.12 N, wt% 0.45 BMCI value 52.1 Mass spectrum composition, wt% Paraffins 19.1 Naphthenes 29.6 Aromatics 51.3

[0063] Table 4 Evaluation results of catalysts of examples and comparative examples

[0064] Catalyst A B C D E F Heavy naphtha, 82-132°C Arom. pot, wt% 58.3 58.5 58.2 58.0 60.1 58.4 Marine fuel, 132-282°C Smoke point, mm 29.5 29.3 29.7 29.8 25.4 29.4 Arom., v% 1.8 2.1 1.6 1.5 13.2 1.7 Diesel, 282-370°C Pour point, °C -7 -7 -7 -8 -7 -4 Arom., wt% 2.5 2.8 2.2 1,8 14.9 2.7 Tail oil, >370°C BMCI value 6.1 6.3 5.8 5.4 17.2 6.2 Viscosity index 123 122 125 126 95 122

[0065] Table 4 Evaluation results of catalysts of Examples and Comparative Examples

[0066] Catalyst G H I J Heavy naphtha, 82-132°C Arom. pot, wt% 60.8 61.1 61.6 61.3 Marine fuel, 132-282°C Smoke point, mm 24.4 23.5 25.1 24.2 Arom., v% 16.2 17.8 20.7 18.9 Diesel, 282-370°C Pour point, °C -7 -8 -7 -7 Arom., wt% 15.4 16.6 19.8 17.7 Tail oil, >370°C BMCI value 19.1 20.8 23.9 21,6 Viscosity index 93 89 84 87

[0067] Table 5 Properties of β molecular sieves in Examples and Comparative Examples

[0068] Si / Al molar ratio 80.5 Specific surface area, m 2 / g]] 621 Pore volume, mL / g 0.55 Total acid by IR, mmol / g 0.43 Na2O, wt% 0.080

Claims

1. A method for preparing a hydrocracking catalyst, characterized in that... The following contents are included: (1) A solution of aluminum salt containing the first hydrogenated active metal, an acidic component slurry and a mixed alkaline solution are added in parallel to a reactor containing bottom water to carry out a gelation reaction to obtain the first gelation product; (2) The solution containing the second hydrogenated active metal, the first gelling product and the mixed alkaline solution are added in parallel to a reactor containing bottom water and phosphate ester compounds to carry out a gelling reaction to obtain the second gelling product; (3) The second gelling product is aged N times. After the N aging is completed, the solid material obtained is prepared into a phosphorus-containing hydrogenation active metal oxide catalyst precursor, and then reduced to obtain a hydrogenation cracking catalyst containing hydrogenation active metal phosphide. Each aging process is as follows: the pH value is adjusted to 11.5~13.5 with 1 / N sodium aluminate solution, and aged for 0.05~0.5 hours; then the pH value is adjusted to 8.5~10.5, and aged for 0.05~0.5 hours; finally, the pH value is adjusted to 4.0~6.2, and aged for 0.05~0.5 hours; where N is an integer from 2 to 8; the first hydrogenation active metal in step (1) is W; the acidic component slurry in step (1) is a mixture of β molecular sieve and deionized water, with a solid-liquid mass ratio of 1:3~1:9; the mixed alkaline solution in steps (1) and (2) is a mixture of ammonia water and sodium phosphate solution, where the molar ratio of ammonia to sodium phosphate is 0.2:1~0.6:1; the concentration of ammonia water is 5wt%~10wt%, and the concentration of sodium phosphate solution is 8wt%~20wt%; the second hydrogenation active metal in step (2) is Ni.

2. The method according to claim 1, characterized in that: In the aluminum salt solution containing the first hydrogenated active metal described in step (1), the weight concentration of W, calculated as WO3, is 5-130 g / L, and the mass concentration of aluminum salt, calculated as Al2O3, is 5-120 g / L.

3. The method according to claim 1, characterized in that: The β-zeolite described in step (1) has the following properties: a silica to alumina molar ratio of 30 to 85, and a specific surface area of ​​350 to 780 m². 2 / g, pore volume 0.30~0.80cm³ 3 / g, the infrared acid concentration is 0.10~0.55mmol / g.

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

5. The method according to claim 1, characterized in that: In step (2), the solution containing the second hydrogenated active metal has a Ni weight concentration of 10-120 g / L, calculated as NiO.

6. The method according to claim 1, characterized in that: The gelation reaction conditions described in step (2) are as follows: reaction temperature is 30-95℃, pH value is controlled between 8.0 and 12.0, and reaction time is 0.5-2.5 hours.

7. The method according to claim 1, characterized in that: The phosphate ester compound mentioned in step (2) is one or more of the following: octadecyl ether phosphate, alkylphenol ether phosphate, isotridecyl ether phosphate, lauryl ether phosphate, castor oil phosphate, octadecyl phosphate, and lauryl phosphate.

8. The method according to claim 1, characterized in that: The molar ratio of the amount of phosphate ester compound added in step (2) to Ni is 0.8:1 to 6.0:

1.

9. The method according to claim 1, characterized in that: The aging temperature described in step (3) is 60–98°C.

10. The method according to claim 1, characterized in that: The sodium aluminate solution mentioned in step (3) has a weight concentration of 5-70 g / L for Al as Al2O3, and the sodium aluminate solution is divided into 2-8 portions by volume according to the number of times it is added.

11. The method according to claim 1, characterized in that: The Al added via sodium aluminate solution accounts for 5% to 55% of the total Al in the obtained hydrocracking catalyst, calculated as Al2O3.

12. The method according to claim 1, characterized in that: The process of preparing the solid material into a phosphorus-containing hydrogenation active metal oxide catalyst precursor in step (3) involves drying, molding, and washing, followed by drying and calcination. The drying conditions are as follows: drying at 40~150℃ for 1~48 hours. During the molding process, one or more of the following are added: a gelling agent and an extrusion aid. The gelling agent is one or more of hydrochloric acid, nitric acid, sulfuric acid, acetic acid, and oxalic acid. The extrusion aid is one or more of guar gum powder, carbon black, graphite powder, and citric acid. The calcination conditions are as follows: calcining at 350~700℃ for 1~24 hours.

13. The method according to claim 1, characterized in that: The reduction in step (3) is carried out in a hydrogen atmosphere. In the first stage, the heating rate is 3~10℃ / min, from room temperature to 300~550℃, and the temperature is held for 1~5 hours. In the second stage, the temperature is raised to 600~750℃ at a heating rate of 0.5~5℃ / min, and the temperature is held for 2~8 hours. The heating rate in the second stage is at least 1℃ / min lower than that in the first stage. The hydrogen purity is greater than 99v%. The hydrogen flow rate is 150~700mL / min.

14. A hydrocracking catalyst prepared by the method according to any one of claims 1 to 13, characterized in that: Based on the weight of the catalyst, the transition metal phosphide WP and Ni2P are 20wt%~68wt%, β molecular sieve is 5wt%~25wt%, and amorphous alumina is 15wt%~65wt%; wherein the mass ratio of Ni2P in the catalyst surface phase to Ni2P in the bulk phase is 2.8:1~7.2:1, the mass ratio of WP in the surface phase to WP in the bulk phase is 2.3:1~6.3:1, and the average particle diameter of the transition metal phosphide is 4~8nm.

15. The hydrocracking catalyst according to claim 14, characterized in that: The Ni / W molar ratio of the hydrocracking catalyst is 0.1:1 to 13:

1.

16. The hydrocracking catalyst according to claim 14, characterized in that: The specific surface area of ​​hydrocracking catalysts is 150~700 m². 2 / g, with a pore volume of 0.25~1.2mL / g.

17. The application of a hydrocracking catalyst prepared by any one of claims 1 to 13 in the hydrocracking process for producing specialty oils.