A hydrocracking catalyst, a preparation method thereof, and an application thereof

Abstract

The present invention discloses a hydrocracking catalyst, a preparation method thereof and an application thereof. The hydrocracking catalyst contains a modified Y-type molecular sieve. The total pore volume of the modified Y-type molecular sieve is 0.50 - 0.62 mL / g, preferably 0.55 - 0.60 mL / g, and the mesopore volume accounts for 40 - 65% of the total pore volume. The preparation method of the catalyst is as follows: (1) preparing a high-silica-alumina ratio nano-cluster Y-type molecular sieve; (2) after ammonium exchange of the high-silica-alumina ratio nano-cluster Y-type molecular sieve in step (1), successively performing hydrothermal treatment and acid treatment; (3) using the molecular sieve treated in step (2) as an acidic cracking component to prepare the final hydrocracking catalyst. This catalyst has good conversion ability for macromolecular aromatics in catalytic diesel and high selectivity for naphtha target products.

Description

Technical Field

[0001] The present invention belongs to the field of hydrocracking catalysts, and relates to a hydrocracking catalyst, a preparation method thereof and an application, specifically to a catalytic diesel hydrocracking catalyst, a preparation method thereof and an application. Background Art

[0002] In recent years, China has experienced an energy transformation stage. The traditional energy-based refinery industry is facing increasingly serious challenges. The domestic demand for diesel has decreased, while the demand for chemical raw materials has increased. At the same time, the domestic market demand for fuel oil has also changed greatly. The increasingly strict environmental protection regulations have also driven the continuous improvement of the quality of fuel oil, and the demand for clean oil products has increased.

[0003] Fluid catalytic cracking (FCC) is one of the important means for heavy oil lightening. Approximately 80 wt% of gasoline and 30 wt% of diesel come from FCC units. Catalytic diesel has high sulfur and nitrogen contents, and the aromatic hydrocarbon content can reach up to 90 wt% at most, and the cetane number is relatively low (about 27). These properties determine that catalytic diesel cannot be directly used for the production of blended diesel. At the same time, in recent years, the crude oil extracted worldwide has become heavier and of lower quality, making the quality of catalytic diesel even worse.

[0004] Naphtha is a basic raw material in the chemical industry, the basic raw material for synthetic fibers, synthetic plastics, and synthetic resins, and can also be used to blend high-octane gasoline. Due to the rapid demand for naphtha in downstream industries, the growth rate of naphtha demand has currently exceeded the demand for fuel oil, and the consumption has increased year by year. Catalytic diesel is rich in aromatic hydrocarbons and is an ideal raw material for producing light aromatic hydrocarbons. Converting low-quality catalytic diesel into high-value-added naphtha using a hydrocracking production process has become a research hotspot in recent years.

[0005] CN112742459 A discloses a preparation method and an application of a hydrocracking catalyst. The patent uses two types of molecular sieves as the active components for catalytic diesel hydrocracking. The first molecular sieve is Y molecular sieve, and the second molecular sieve is a molecular sieve with a smaller pore size than Y molecular sieve, which can be one or several of beta molecular sieve, ZSM-5, and ZRP-5. The catalyst has high selective hydrogenation activity and high ring-opening performance, and can improve the yields of gasoline and light aromatic hydrocarbons.

[0006] CN111100705 A discloses a method for maximizing the production of aromatic hydrocarbons from catalytic diesel. The invention optimizes the catalyst grading method, effectively balances the problems of catalyst activity and excessive conversion of aromatic hydrocarbons, reduces the formation of carbon deposition in the catalyst bed layer, and improves the selectivity of light aromatic hydrocarbon products.

[0007] CN103120955B discloses a catalyst for preparing monocyclic aromatic hydrocarbons from polycyclic aromatic hydrocarbons. Aiming at the problems of insufficient conversion ability of polycyclic aromatic hydrocarbons and low yield of light aromatic hydrocarbons, the catalyst uses a mixture of FAU zeolite and at least one zeolite selected from MOR, BEA, MFI, and MCM-22 as the cracking component, and the hydrogenation metal uses at least one of Pt, Pd, or Ir. This catalyst has good activity for polycyclic aromatic hydrocarbon feedstock oil.

[0008] In summary, the content of polycyclic aromatic hydrocarbons in catalytic diesel is relatively high. The pore diameter of Y zeolite is small, the crystal grain size is large, the pore channel length is long, and aromatics can only react using limited external surface acid sites, resulting in limited conversion ability for large molecular aromatics and prone to problems such as coke deposition deactivation during long-term operation. Summary of the Invention

[0009] Aiming at the deficiencies of the prior art, the present invention provides a catalytic diesel hydrocracking catalyst, its preparation method, and application. This catalyst uses the modified nano-cluster Y zeolite as the main acidic component. The modified nano-cluster Y zeolite retains the advantages of nano-Y zeolite, has relatively rich acid sites on its external surface, has good conversion ability for large molecular aromatics in catalytic diesel, and has high selectivity for naphtha target products.

[0010] A hydrocracking catalyst, based on the weight of the final hydrocracking catalyst, the hydrocracking catalyst contains 20 - 70 wt%, preferably 40 - 60 wt% of modified Y zeolite (obtained by modifying nano-cluster Y zeolite), contains 3 - 35 wt%, preferably 5 - 25 wt% of hydrogenation metal oxide. The total pore volume of the modified Y zeolite is 0.50 - 0.62 mL / g, preferably 0.55 - 0.60 mL / g, and the mesopore volume accounts for 40 - 65% of the total pore volume, preferably 52 - 62%; the relative crystallinity of the modified Y zeolite is 90 - 96%, preferably 92 - 95%.

[0011] In the catalyst of the present invention, the hydrocracking catalyst further contains one or several of alumina and amorphous silica-alumina.

[0012] In the catalyst of the present invention, the hydrogenation metal is a Group VIB metal and / or a Group VIII metal. The Group VIB metal is preferably Mo and / or W; the Group VIII metal is preferably Co and / or Ni. Based on the weight of the final hydrocracking catalyst, the content of Group VIB metal oxide is preferably 5 - 17 wt%, and the content of Group VIII metal oxide is 1 - 8 wt%.

[0013] In the catalyst of the present invention, the silica-alumina ratio (SiO 2 / Al 2 O3 is 8 - 50, preferably 12 - 25; the unit cell constant of the modified molecular sieve is 24.25 - 24.51 Å, preferably 24.31 - 24.43 Å.

[0014] In the catalyst of the present invention, the specific surface area of the modified Y molecular sieve is 600 - 880 m 2 / g, preferably 750 - 850 m 2 / g; the pyridine infrared acid content of the modified Y molecular sieve is 0.10 - 1.20 mmol / g, preferably 0.50 - 1.00 mmol / g; the Na 2 O content in the modified Y molecular sieve is 0.03 - 0.30 wt%.

[0015] A preparation method of a hydrocracking catalyst, the method comprising the following steps:

[0016] (1) Prepare a high silica - alumina ratio nano - cluster Y - type molecular sieve;

[0017] (2) After ammonium exchange of the high silica - alumina ratio nano - cluster Y - type molecular sieve in step (1), successively carry out hydrothermal treatment and

[0018] acid treatment;

[0019] (3) Use the molecular sieve treated in step (2) as the acidic cracking component to prepare the final hydrocracking catalyst.

[0020]

[0021] In step (1) of the method of the present invention, for the prepared high silica - alumina ratio nano - cluster Y - type molecular sieve, the silica - alumina molar ratio (SiO 2 / Al 2 O 3 ) is 5.5 - 7.5, preferably 6.5 - 7.0. The nano - cluster Y molecular sieve is an aggregate formed by clustering of small crystals, the nano - crystal size is 80 - 150 nm, preferably 100 - 130 nm; the nano - cluster size is 1.0 μm - 3.0 μm, preferably 1.2 μm - 1.8 μm. The specific surface area of the molecular sieve is 800 - 920 m 2 / g, preferably 840 - 880 m 2 / g, the external specific surface area is 80 - 130 m 2 / g, preferably 100 - 120 m 2 / g.

[0022] ​In step (1) of the method of the present invention, the prepared high-silica-alumina nano-cluster Y zeolite, after ammonium exchange, is hydrothermally treated at 600 °C and 0.1 MPa for 2 h. The relative crystallinity of the Y zeolite after hydrothermal treatment is 80-92%, preferably 83-88%. The crystallinity retention rate of the high-silica-alumina nano-cluster Y zeolite compared with that before hydrothermal treatment is 80-93%.

[0023] In step (1) of the method of the present invention, the preparation of the high-silica-alumina nano-cluster Y zeolite uses fatty alcohol polyoxyethylene ether sulfate (AES) as a template agent. The molecular formula of the fatty alcohol polyoxyethylene ether sulfate (AES) is RO(CH 2 CH 2 O) n -SO 3 M, where R is an alkyl group, which can be one or several of dodecyl, tridecyl, tetradecyl, pentadecyl; n is the degree of polymerization, and n is an integer greater than 1, for example, it can be 2, 3, or 4; M is a cation, which can be one or several of Na, NH 4 , K. The method of the present invention uses fatty alcohol polyoxyethylene ether sulfate as a template agent to synthesize a high-silica-alumina nano-cluster Y zeolite. Fatty alcohol polyoxyethylene ether sulfate is a type of surfactant with amphoteric groups. It contains rich C-O-C bonds and S-O bonds. The presence of these hydrophilic groups makes the template agent have a high solubility, and the synthesis process can be carried out in a high-concentration template agent system, so that the zeolite crystals self-assemble into high-silica-alumina Y zeolite clusters; fatty alcohol polyoxyethylene ether sulfate is unstable at high crystallization temperatures and will undergo hydrolysis. The -OH generated during hydrolysis can promote crystal growth, reduce the reaction activation energy of Si-O-Si, facilitate the polymerization reaction between silicate ions, reduce the combination probability of silicate ions and aluminate ions, and increase the silica-alumina ratio of the Y zeolite nano-cluster.

[0024] In step (1) of the method of the present invention, the preparation of the high-silica-alumina nano-cluster Y zeolite includes the following: a mixed material containing an alkali source, an aluminum source, a silicon source, and fatty alcohol polyoxyethylene ether sulfate (AES) is subjected to crystallization, washing, filtration, drying, and calcination to obtain the final high-silica-alumina nano-cluster Y zeolite. The alkali source is sodium hydroxide; the aluminum source is one or several of aluminum isopropoxide, aluminum powder, sodium metaaluminate, aluminum sulfate octadecahydrate, and aluminum hydroxide; the silicon source is one or several of silica sol, sodium silicate, tetraethyl orthosilicate, fumed silica, and water glass. The fatty alcohol polyoxyethylene ether sulfate / SiO 2 (based on SiO 2The molar ratio (calculated based on the silicon source dosage) is 0.05 - 0.25, preferably 0.10 - 0.20. By controlling the concentration of fatty alcohol polyoxyethylene ether sulfate in the solution, a nano-cluster Y-type molecular sieve with a high silicon-aluminum ratio can be prepared. The molar ratio of the mixed materials is: Al 2 O 3 : (9.0 - 16.0)SiO 2 : (4.0 - 7.0)Na 2 O: (150 - 350)H 2 O: (0.5 - 3.0)AES; preferably Al 2 O 3 : (11.0 - 14.0)SiO 2 : (5.0 - 6.0)Na 2 O: (200 - 280)H 2 O: (1.0 - 2.0)AES. The crystallization temperature is 90 - 110 °C, preferably 95 - 105 °C; the crystallization time is 40 - 90 h, preferably 50 - 70 h. First, it is crystallized at 20 - 50 °C, preferably 30 - 45 °C for 20 - 40 h, preferably 25 - 35 h; then it is crystallized at 90 - 110 °C, preferably 95 - 105 °C for 40 - 90 h, preferably 50 - 70 h. The drying temperature is 100 - 120 °C, the time is 7 - 13 h, the calcination temperature is 450 - 550 °C, and the time is 4 - 6 h. In the crystallization process of this synthesis method, it is mainly divided into two stages: the first stage is the low-temperature crystallization stage. The main purpose of this stage is to form more crystal nuclei of the molecular sieve at low temperature. At the same time, under the action of the template agent, the small crystal grains in the initial growth stage are aggregated together to form a cluster-like morphology. The second stage is the high-temperature crystallization stage. Fatty alcohol polyoxyethylene ether sulfate is unstable at high temperature and will undergo hydrolysis. The -OH generated during the hydrolysis process can promote crystal growth, reduce the reaction activation energy of Si-O-Si, facilitate the polymerization reaction between silicate ions, reduce the combination probability of silicate ions and aluminate ions, further increase the silicon-aluminum ratio of the Y molecular sieve nano-clusters, while reducing the size of nano-crystals and nano-clusters, and improving the hydrothermal stability.

[0025] In step (2) of the method of the present invention, the ammonium salt used for ammonium exchange is one or more of ammonium nitrate, ammonium chloride, ammonium sulfate, ammonium acetate, and ammonium oxalate. The ammonium exchange temperature is 40 - 96 °C, preferably 70 - 90 °C, the number of exchange times is 2 - 4 times, and the ammonium salt concentration is 0.5 mol / L - 3.0 mol / L. The solid-liquid ratio of ammonium exchange is 1:5 - 1:20, preferably 1:8 - 1:15.

[0026] In step (2) of the method of the present invention, the hydrothermal treatment temperature is 500 - 700 °C, preferably 550 - 650 °C; the hydrothermal pressure is 0.05 - 0.20 MPa, preferably 0.08 - 0.15 MPa; the hydrothermal treatment time is 1 - 10 h, preferably 2 - 4 h.

[0027] In step (2) of the method of the present invention, the acid used for the acid treatment is an inorganic acid or an organic acid, or a combination of both can be used. When the inorganic acid and the organic acid are used in combination for treatment, the inorganic acid can be used first followed by the organic acid treatment, or the organic acid can be used first followed by the inorganic acid treatment. The inorganic acid used can be one or more of nitric acid, hydrochloric acid, and sulfuric acid, and the organic acid can be one or more of citric acid, oxalic acid, EDTA, and tartaric acid.

[0028] In the solution used for the acid treatment in step (2) of the method of the present invention, the acid concentration of the acid is 0.1 - 2.5 mol / L, preferably 0.5 - 2.0 mol / L; an ammonium salt can be further added to the solution, and the ammonium salt concentration in the solution is 0.1 - 2.0 mol / L, preferably 0.5 - 1.5 mol / L. The ammonium salt is one or more of ammonium nitrate, ammonium chloride, ammonium sulfate, ammonium acetate, and ammonium oxalate.

[0029] In step (2) of the method of the present invention, in step (4), the temperature of the acid treatment is 20 - 90 °C, preferably 40 - 70 °C. The acid treatment time is 0.5 - 6 h, preferably 2 - 3 h. The solid-liquid volume ratio during the acid treatment is 1:5 - 1:20, preferably 1:10 - 1:15.

[0030] In step (3) of the method of the present invention, the catalyst can be prepared by the kneading method or the impregnation method. The kneading method is to mix the molecular sieve, alumina and / or amorphous silica-alumina, active metal oxide and / or active metal salt treated in step (2) evenly, then add dilute nitric acid solution and distilled water, and obtain the shaped catalyst after rolling and extrusion. The shaped catalyst is dried and calcined to obtain the final hydrocracking catalyst. The impregnation method is to load the active metal on the shaped molecular sieve, alumina and / or amorphous silica-alumina treated in step (2), and obtain the final hydrocracking catalyst after drying and calcining.

[0031] In step (3) of the method of the present invention, in the preparation method of the hydrocracking catalyst, the active metal is a Group VIB metal and / or a Group VIII metal. The Group VIB metal is preferably Mo or W, and the Group VIII metal is preferably Co or Ni. The drying temperature of the shaped catalyst is 100 - 150 °C, and the catalyst calcination temperature is 450 - 550 °C.

[0032] The catalyst prepared above is used for catalyzing the hydrocracking reaction of diesel oil, and the reaction conditions are as follows: the reaction temperature is 350 - 430 °C, the reaction pressure is 4 - 10 MPa, the reaction volume space velocity is 0.5 - 2.0 h -1 , and the hydrogen-oil ratio is 800:1 - 1400:1.

[0033] In the present invention, the modified nano-cluster Y zeolite is used as the active component of the hydrocracking catalyst. The nano-cluster Y zeolite is a spherical aggregate formed by stacking many nano-crystallites. Compared with the traditional Y zeolite, it can expose more external surface acid sites; compared with the conventional nano-Y zeolite, it has better stability. The modified Y zeolite has a smooth and open mesoporous structure, which is suitable for catalyzing the hydroconversion reaction of diesel oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 XRD diffraction pattern of the Y zeolite prepared in Example 3.

[0035] Figure 2 SEM image of the Y zeolite prepared in Example 3 at 50k magnification.

[0036] Figure 3 SEM image of the Y zeolite prepared in Example 3 at 5k magnification. DETAILED DESCRIPTION OF THE INVENTION

[0037] A specific preparation method of a high-silica-alumina nano-cluster Y zeolite in the method of the present invention, the method includes the following steps:

[0038] 1), First, prepare a template agent solution. Dissolve a certain amount of fatty alcohol polyoxyethylene ether sulfate in water, and then, under stirring, dissolve the alkali source and the aluminum source in a certain amount of distilled water, stir until dissolved, and then add the silicon source to the above aluminum source solution. Gel is formed at room temperature. Add the template agent solution to the gelled solution, stir at room temperature for a period of time, and then crystallize at low temperature for a period of time.

[0039] 2), Place the solution after low-temperature crystallization in a high-temperature oven for high-temperature crystallization. After completion, take it out, wash, filter, dry, and calcine to obtain the final nano-cluster Y zeolite product.

[0040] In step 1) of the method of the present invention, the fatty alcohol polyoxyethylene ether sulfate (AES) has the molecular formula RO(CH 2 CH 2 O) n -SO 3 M, where R is an alkyl group, which can be one or several of dodecyl, tridecyl, tetradecyl, and pentadecyl; n is the degree of polymerization, n is an integer greater than 1, for example, it can be 2, 3, or 4; M is a cation, which can be Na, NH4 , one or more of K.

[0041] In step 1) of the method of the present invention, the alkali source is sodium hydroxide; the aluminum source is one or more of aluminum isopropoxide, aluminum powder, sodium metaaluminate, aluminum sulfate octadecahydrate, and aluminum hydroxide; the silicon source is one or more of silica sol, sodium silicate, tetraethyl orthosilicate, silica white, and water glass.

[0042] In step 1) of the method of the present invention, fatty alcohol polyoxyethylene ether sulfate / SiO 2 (the dosage of silicon source calculated as SiO 2 ) has a molar ratio of 0.05 - 0.25, preferably 0.10 - 0.20.

[0043] In step 1) of the method of the present invention, the molar ratio of the materials is: Al 2 O 3 : (9.0 - 16.0)SiO 2 : (4.0 - 7.0)Na 2 O: (150 - 350)H 2 O: (0.5 - 3.0)AES; preferably Al 2 O 3 : (11.0 - 14.0)SiO 2 : (5.0 - 6.0)Na 2 O: (200 - 280)H 2 O: (1.0 - 2.0)AES.

[0044] In step 1) of the method of the present invention, low-temperature crystallization is carried out at 20 - 50 °C, preferably 30 - 45 °C for 20 - 40 h, preferably 25 - 35 h.

[0045] In step 2) of the method of the present invention, high-temperature crystallization is carried out at 90 - 110 °C, preferably 95 - 105 °C for 40 - 90 h, preferably 50 - 70 h.

[0046] In step 2) of the method of the present invention, the drying temperature is 100 - 120 °C, the time is 7 - 13 h, the calcination temperature is 450 - 550 °C, and the time is 4 - 6 h.

[0047] The characterization method of the nano-cluster Y-type molecular sieve in the present invention is as follows:

[0048] The specific surface area and pore volume of the molecular sieve are measured by the N 2 -adsorption and desorption method. Before measurement, the sample is first pretreated at 300 °C for 3 h, and then nitrogen is adsorbed at 77 K for testing. The specific surface area of the molecular sieve is calculated by the BET method, and the total pore volume is at p / p 0Measured at = 0.98, the external specific surface area was obtained by the t-Plot method.

[0049] The unit cell constant of the molecular sieve was measured by X-ray diffraction method. The unit cell constant a was measured according to the industry standard SH / T 0339 - 92 of China National Petroleum and Chemical Industry. 0 。

[0050] The relative crystallinity of the molecular sieve was measured by XRD diffraction method. The measurement method was according to the industry standard SH / T 0340 - 92 of China National Petroleum and Chemical Industry. The retention rate of the crystallinity of the molecular sieve after hydrothermal treatment was calculated based on the molecular sieve before hydrothermal treatment. According to the principle that the X-ray diffraction intensity of the crystalline phase is proportional to the content of this crystalline phase, X-ray diffraction was used for quantitative analysis.

[0051] The silica-alumina ratio (SiO 2 / Al 2 O 3 ), and the content of Na 2 O were measured by X-ray fluorescence method (XRF).

[0052] The acid content of the molecular sieve was measured by pyridine-infrared spectroscopy (Py-FTIR). The sample was prepared into a self-supporting film, heated to 500 °C and maintained for 2 h, then evacuated. After the sample cooled naturally, pyridine was adsorbed at room temperature for 30 min when it cooled to room temperature, and then heated to 150 °C and evacuated to remove the physically adsorbed pyridine molecules. The pyridine infrared spectrum at this temperature was recorded. After integrating the peak area of the spectrum, the infrared acid content was obtained.

[0053] The functions and effects of the method of the present invention will be further described below in conjunction with the examples and comparative examples. However, the following examples do not limit the method of the present invention.

[0054] The Y molecular sieve used in the modification treatment in Comparative Example 1 was a commercial NaY molecular sieve. The properties of the NaY molecular sieve were: specific surface area 880 m 2 / g, external specific surface area 42 m 2 / g, silica-alumina ratio (SiO 2 / Al 2 O 3 ) was 5.2, relative crystallinity was 102%, and crystal grain size was 1.2 μm.

[0055] The Y molecular sieve used in the modification treatment in Comparative Example 2 was a conventional nanocluster NaY molecular sieve. Using conventional CTAB as a template agent, a low silica-alumina ratio nanocluster NaY molecular sieve was synthesized as the product.

[0056] The specific preparation methods of the modified Y molecular sieves in the examples and comparative examples are as follows:

[0057] Example 1

[0058] Preparation of nano - cluster Y - type molecular sieve:

[0059] (1) First, prepare the template agent solution. Add ammonium lauryl polyoxyethylene ether sulfate to water, stir until completely dissolved, and store it sealed. Under stirring, add sodium hydroxide and sodium aluminate to water. After stirring evenly, add silica sol and form a gel at room temperature.

[0060] (2) Add the prepared template agent solution and stir evenly. At this time, the solution composition is Al 2 O 3 : 11.0SiO 2 :5.0Na 2 O: 230H 2 O: 1.6 AES, and the AES / SiO 2 in the solution is 0.15. Crystallize the solution at 30 °C for 35 h, and then crystallize it at 97 °C for 60 h. After crystallization, take it out, wash, filter, dry, and calcine to obtain the final nano - cluster Y - type molecular sieve product.

[0061] Modification of nano - cluster Y molecular sieve: Add the prepared nano - cluster NaY molecular sieve to distilled water, add ammonium chloride, control the ammonium exchange temperature at 90 °C, the solid - liquid ratio at 1:10, the number of ammonium exchange times at 3 times, and the ammonium salt concentration at 2.0 mol / L. After ammonium exchange, perform high - temperature hydrothermal treatment on the molecular sieve. The hydrothermal treatment temperature is 600 °C, the hydrothermal time is 2 h, and the hydrothermal pressure is 0.10 MPa. Add the hydrothermally treated molecular sieve to distilled water, start stirring, stir until the molecular sieve is evenly dispersed, then add hydrochloric acid and ammonium chloride, control the solid - liquid ratio of acid treatment at 1:10, the hydrochloric acid concentration at 0.7 mol / L, the ammonium chloride concentration at 0.7 mol / L, the treatment temperature at 70 °C, and the acid treatment time at 2 h. After the acid treatment, wash and filter the molecular sieve, dry it at 100 °C for 8 h, and calcine it at 500 °C for 4 h to obtain the final modified molecular sieve Y - 1.

[0062] Example 2

[0063] Preparation of nano - cluster Y - type molecular sieve:

[0064] (1) First, prepare the template agent solution. Add ammonium tridecyl polyoxyethylene ether sulfate to water, stir until completely dissolved, and store it sealed. Under stirring, add sodium hydroxide and sodium aluminate to water. After stirring evenly, add silica sol and form a gel at room temperature.

[0065] (2) Add the prepared template agent solution and stir evenly. At this time, the solution composition is Al 2 O 3 : 14.0SiO 2 :5.8Na 2 O: 280H 2O: 2.0 AES, AES / SiO in the solution 2 is 0.14. The solution is crystallized at a low temperature of 45 °C for 27 h, and then crystallized at 105 °C for 50 h. After crystallization, it is taken out, washed, filtered, dried, and calcined to obtain the final nano-cluster Y-type molecular sieve product.

[0066] Modification of nano-cluster Y molecular sieve: The prepared nano-cluster NaY molecular sieve is added to distilled water, ammonium chloride is added, the ammonium exchange temperature is controlled at 90 °C, the solid-liquid ratio is 1:10, the number of ammonium exchange times is 3 times, and the ammonium salt concentration is 2.0 mol / L. After ammonium exchange, the molecular sieve is hydrothermally treated at a high temperature. The hydrothermal treatment temperature is 600 °C, the hydrothermal time is 2 h, and the hydrothermal pressure is 0.10 MPa. The hydrothermally treated molecular sieve is added to distilled water, stirred until the molecular sieve is evenly dispersed, and then hydrochloric acid and ammonium chloride are added. The solid-liquid ratio of acid treatment is controlled at 1:10, the hydrochloric acid concentration is 0.7 mol / L, the ammonium chloride concentration is 0.7 mol / L, the treatment temperature is 70 °C, and the acid treatment time is 2 h. After the treated molecular sieve is washed and filtered, it is dried at 100 °C for 8 h and calcined at 500 °C for 4 h to obtain the final modified molecular sieve Y-2.

[0067] Example 3

[0068] Preparation of nano-cluster Y-type molecular sieve:

[0069] (1) First, prepare a template agent solution. Add ammonium lauryl polyoxyethylene ether sulfate to water, stir until completely dissolved, and store it sealed. Under stirring, add sodium hydroxide and sodium aluminate to water, stir evenly, and then add silica sol to form a gel at room temperature.

[0070] (2) Add the prepared template agent solution and stir evenly. At this time, the solution composition is Al 2 O 3 : 11.0 SiO 2 : 5.6 Na 2 O: 245 H 2 O: 1.1 AES, AES / SiO in the solution 2 is 0.10. The solution is crystallized at a low temperature of 39 °C for 25 h, and then crystallized at 100 °C for 70 h. After crystallization, it is taken out, washed, filtered, dried, and calcined to obtain the final nano-cluster Y-type molecular sieve product.

[0071] Modification of nano-cluster Y zeolite: The prepared nano-cluster NaY zeolite was added to distilled water, and ammonium chloride was added. The ammonium exchange temperature was controlled at 90 °C, the solid-liquid ratio was 1:10, the number of ammonium exchange times was 3 times, and the ammonium salt concentration was 2.0 mol / L. After ammonium exchange, the zeolite was subjected to high-temperature hydrothermal treatment. The hydrothermal treatment temperature was 600 °C, the hydrothermal time was 2 h, and the hydrothermal pressure was 0.10 MPa. The hydrothermally treated zeolite was added to distilled water, and stirring was started until the zeolite was evenly dispersed. Then, hydrochloric acid and ammonium chloride were added. The solid-liquid ratio for acid treatment was controlled at 1:10, the hydrochloric acid concentration was 0.7 mol / L, the ammonium chloride concentration was 0.7 mol / L, the treatment temperature was 70 °C, and the acid treatment time was 2 h. After treatment, the zeolite was washed, filtered, dried at 100 °C for 8 h, and calcined at 500 °C for 4 h to obtain the final modified zeolite Y-3.

[0072] Example 4

[0073] Preparation of nano-cluster Y zeolite:

[0074] (1) First, prepare a template agent solution. Sodium dodecyl polyoxyethylene ether sulfate was added to water and stirred until completely dissolved, then sealed for storage. Under stirring, sodium hydroxide and sodium aluminate were added to water. After stirring evenly, silica sol was added, and gelation occurred at room temperature.

[0075] (2) Add the prepared template agent solution and stir evenly. At this time, the solution composition was Al 2 O 3 : 9.5SiO 2 :4.2Na 2 O: 160H 2 O: 0.5 AES, and the AES / SiO 2 in the solution was 0.05. The solution was crystallized at 20 °C for 40 h, and then at 110 °C for 40 h. After crystallization, it was taken out, washed, filtered, dried, and calcined to obtain the final nano-cluster Y zeolite product.

[0076] Modification of nano-cluster Y zeolite: The prepared nano-cluster NaY zeolite was added to distilled water, and ammonium chloride was added. The ammonium exchange temperature was controlled at 90 °C, the solid-liquid ratio was 1:10, the number of ammonium exchange times was 3 times, and the ammonium salt concentration was 2.0 mol / L. After ammonium exchange, the zeolite was subjected to high-temperature hydrothermal treatment. The hydrothermal treatment temperature was 600 °C, the hydrothermal time was 2 h, and the hydrothermal pressure was 0.10 MPa. The hydrothermally treated zeolite was added to distilled water, and stirring was started until the zeolite was evenly dispersed. Then, hydrochloric acid and ammonium chloride were added. The solid-liquid ratio for acid treatment was controlled at 1:10, the hydrochloric acid concentration was 0.7 mol / L, the ammonium chloride concentration was 0.7 mol / L, the treatment temperature was 70 °C, and the acid treatment time was 2 h. After treatment, the zeolite was washed, filtered, dried at 100 °C for 8 h, and calcined at 500 °C for 4 h to obtain the final modified zeolite Y-4.

[0077] Example 5

[0078] Preparation of nano-cluster Y zeolite:

[0079] (1) First, prepare a template solution. Add ammonium dodecyl polyoxyethylene ether sulfate to water, stir until completely dissolved, and store it sealed. Under stirring, add sodium hydroxide and sodium aluminate to water, stir evenly, and then add silica sol to form a gel at room temperature.

[0080] (2) Add the prepared template solution and stir evenly. At this time, the solution composition is Al 2 O 3 : 16.0SiO 2 :7.0Na 2 O: 350H 2 O: 3.0AES, and the AES / SiO 2 in the solution is 0.19. Crystallize the solution at a low temperature of 50 °C for 20 h, and then crystallize it at 93 °C for 90 h. After crystallization, take it out, wash, filter, dry, and calcine to obtain the final nano-cluster Y zeolite product.

[0081] Modification of nano-cluster Y zeolite: Add the prepared nano-cluster NaY zeolite to distilled water, add ammonium chloride, control the ammonium exchange temperature at 90 °C, the solid-liquid ratio at 1:10, the number of ammonium exchange times at 3 times, and the ammonium salt concentration at 2.0 mol / L. After ammonium exchange, perform high-temperature hydrothermal treatment on the zeolite. The hydrothermal treatment temperature is 600 °C, the hydrothermal time is 2 h, and the hydrothermal pressure is 0.10 MPa. Add the hydrothermally treated zeolite to distilled water, start stirring, stir until the zeolite is evenly dispersed, and then add hydrochloric acid and ammonium chloride. Control the solid-liquid ratio of acid treatment at 1:10, the hydrochloric acid concentration at 0.7 mol / L, the ammonium chloride concentration at 0.7 mol / L, the acid treatment temperature at 70 °C, and the acid treatment time at 2 h. After the treated zeolite is washed and filtered, dry it at 100 °C for 8 h and calcine it at 500 °C for 4 h to obtain the final modified zeolite Y-5.

[0082] Comparative Example 1

[0083] Modification of Y zeolite: Commercial large-grained NaY zeolite was added to distilled water, and ammonium chloride was added. The ammonium exchange temperature was controlled at 90 °C, the solid-liquid ratio was 1:10, the number of ammonium exchange times was 3 times, and the ammonium salt concentration was 2.0 mol / L. After ammonium exchange, the zeolite was subjected to high-temperature hydrothermal treatment. The hydrothermal treatment temperature was 600 °C, the hydrothermal time was 2 h, and the hydrothermal pressure was 0.10 MPa. The hydrothermally treated zeolite was added to distilled water, stirred until the zeolite was evenly dispersed, and then hydrochloric acid and ammonium chloride were added. The solid-liquid ratio for acid treatment was controlled at 1:10, the hydrochloric acid concentration was 0.7 mol / L, the ammonium chloride concentration was 0.7 mol / L, the treatment temperature was 70 °C, and the acid treatment time was 2 h. After treatment, the zeolite was washed, filtered, dried at 100 °C for 8 h, and calcined at 500 °C for 4 h to obtain the final modified zeolite CY-1.

[0084] Comparative Example 2

[0085] Preparation of conventional nanocluster Y zeolite:

[0086] (1) First, prepare a template agent solution. CTAB was added to water, stirred until completely dissolved, and stored sealed. Under stirring, sodium hydroxide and sodium aluminate were added to water. After stirring evenly, silica sol was added, and gelation occurred at room temperature.

[0087] (2) Add the prepared template agent solution and stir evenly. At this time, the solution composition was Al 2 O 3 : 11.0SiO 2 :5.6Na 2 O: 245H 2 O: 1.1CTAB, and the CTAB / SiO 2 in the solution was 0.10. The solution was crystallized at 39 °C for 25 h, and then at 100 °C for 70 h. After crystallization, it was taken out, washed, filtered, dried, and calcined to obtain the final nanocluster Y-type zeolite product.

[0088] Modification of nanocluster Y zeolite: Nanocluster NaY zeolite was added to distilled water, and ammonium chloride was added. The ammonium exchange temperature was controlled at 90 °C, the solid-liquid ratio was 1:10, the number of ammonium exchange times was 3 times, and the ammonium salt concentration was 2.0 mol / L. After ammonium exchange, the zeolite was subjected to high-temperature hydrothermal treatment. The hydrothermal treatment temperature was 600 °C, the hydrothermal time was 2 h, and the hydrothermal pressure was 0.10 MPa. The hydrothermally treated zeolite was added to distilled water, stirred until the zeolite was evenly dispersed, and then hydrochloric acid and ammonium chloride were added. The solid-liquid ratio for acid treatment was controlled at 1:10, the hydrochloric acid concentration was 0.7 mol / L, the ammonium chloride concentration was 0.7 mol / L, the treatment temperature was 70 °C, and the acid treatment time was 2 h. After treatment, the zeolite was washed, filtered, dried at 100 °C for 8 h, and calcined at 500 °C for 4 h to obtain the final modified zeolite CY-2.

[0089] In the examples and comparative examples, the properties of the molecular sieves and the modified molecular sieves are shown in Tables 2 and 3.

[0090] In the present invention, a specific preparation method of a catalytic diesel hydrocracking catalyst includes: adding the modified Y-type molecular sieve, alumina powder, metal salt or metal oxide into a rolling mill, adding nitric acid and distilled water with a certain concentration, mixing evenly, extruding into strips, drying and calcining to obtain the catalyst, and finally obtaining the hydrocracking catalyst. The contents of the molecular sieve, alumina, and metal oxide are calculated based on the dry basis after the catalyst is calcined in a muffle furnace at 500 °C for 4 h and cooled to room temperature.

[0091] In the examples and comparative examples, the specific preparation methods of the catalytic diesel hydrocracking catalysts are as follows, but the following preparation methods do not limit the present invention:

[0092] Example 6

[0093] Add the modified molecular sieve Y-1 with a dry basis content of 45 wt%, alumina powder with a content of 37 wt%, nickel nitrate with a nickel oxide content of 4.5 wt%, and molybdenum oxide with a molybdenum oxide content of 13.5 wt% into a rolling mill. After mixing evenly, add a nitric acid solution and distilled water with a certain concentration, roll and mix until uniform, extrude into strips, dry at 100 °C for 6 h, and then put it into a muffle furnace at 500 °C for 4 h to obtain the final hydrocracking catalyst.

[0094] Example 7

[0095] Add the modified molecular sieve Y-2 with a dry basis content of 45 wt%, alumina powder with a content of 37 wt%, nickel nitrate with a nickel oxide content of 4.5 wt%, and molybdenum oxide with a molybdenum oxide content of 13.5 wt% into a rolling mill. After mixing evenly, add a nitric acid solution and distilled water with a certain concentration, roll and mix until uniform, extrude into strips, dry at 100 °C for 6 h, and then put it into a muffle furnace at 500 °C for 4 h to obtain the final hydrocracking catalyst.

[0096] Example 8

[0097] Add the modified molecular sieve Y-3 with a dry basis content of 45 wt%, alumina powder with a content of 37 wt%, nickel nitrate with a nickel oxide content of 4.5 wt%, and molybdenum oxide with a molybdenum oxide content of 13.5 wt% into a rolling mill. After mixing evenly, add a nitric acid solution and distilled water with a certain concentration, roll and mix until uniform, extrude into strips, dry at 100 °C for 6 h, and then put it into a muffle furnace at 500 °C for 4 h to obtain the final hydrocracking catalyst.

[0098] Example 9

[0099] The modified molecular sieve Y-4 with a dry basis content of 45 wt%, 37 wt% of alumina powder, nickel nitrate with a nickel oxide content of 4.5 wt%, and molybdenum oxide with a molybdenum oxide content of 13.5 wt% are added into a rolling machine. After mixing evenly, a nitric acid solution with a certain concentration and distilled water are added, and the mixture is rolled and mixed until uniform, then extruded into strips, dried at 100 °C for 6 h, and then calcined in a muffle furnace at 500 °C for 4 h to obtain the final hydrocracking catalyst.

[0100] Comparative Example 3

[0101] The modified molecular sieve CY-1 with a dry basis content of 45 wt%, 37 wt% of alumina powder, nickel nitrate with a nickel oxide content of 4.5 wt%, and molybdenum oxide with a molybdenum oxide content of 13.5 wt% are added into a rolling machine. After mixing evenly, a nitric acid solution with a certain concentration and distilled water are added, and the mixture is rolled and mixed until uniform, then extruded into strips, dried at 100 °C for 6 h, and then calcined in a muffle furnace at 500 °C for 4 h to obtain the final hydrocracking catalyst.

[0102] Comparative Example 4

[0103] The modified molecular sieve CY-2 with a dry basis content of 45 wt%, 37 wt% of alumina powder, nickel nitrate with a nickel oxide content of 4.5 wt%, and molybdenum oxide with a molybdenum oxide content of 13.5 wt% are added into a rolling machine. After mixing evenly, a nitric acid solution with a certain concentration and distilled water are added, and the mixture is rolled and mixed until uniform, then extruded into strips, dried at 100 °C for 6 h, and then calcined in a muffle furnace at 500 °C for 4 h to obtain the final hydrocracking catalyst.

[0104] The component compositions of the above hydrocracking catalysts are listed in Table 3.

[0105] The performance evaluation of the catalyst is carried out on a small-scale micro-reactor device, adopting a one-stage series once-through process flow. The reaction feedstock oil passes through the refining reactor and the cracking reactor in sequence. The evaluation conditions and evaluation results are listed in Table 5 and Table 6 respectively. For the cracking catalyst in the hydrocracking reaction, the feedstock oil is catalytic diesel, and the properties of the feedstock oil are listed in Table 1, and the target product is heavy naphtha. The catalyst evaluation experiment is carried out on a micro-reactor device, adopting a once-through, one-stage series process flow. The feedstock oil passes through two series-connected reactors in succession, and no fractionation device is installed between the two reactors. The feedstock oil first passes through the refining reactor, and the refining reactor is equipped with a conventional refining agent, mainly to remove impurities such as S and N, and then undergoes a cracking reaction through the cracking reactor equipped with this catalyst, and the reaction products are collected for analysis.

[0106] It can be seen from the catalyst evaluation conditions and results that the catalyst in the present invention has better ring-opening activity for bicyclic and higher aromatic hydrocarbons and a lower cracking temperature. Compared with the traditional Y zeolite, it has better selectivity for the heavy naphtha product.

[0107] Table 1. Properties of feedstock oil

[0108]

[0109] Table 2. Properties of synthesized molecular sieves

[0110]

[0111] Table 3. Properties of modified molecular sieves

[0112]

[0113] Table 4. Component composition of hydrocracking catalysts

[0114]

[0115] Table 5. Catalyst evaluation conditions

[0116]

[0117] Table 6. Catalyst evaluation results

[0118] Example 6 Example 7 Example 8 Example 9 Comparative Example 3 Comparative Example 4 Yield of heavy naphtha at 65 - 165°C, % 59.2 58.4 57.0 56.3 52.6 53.5 Liquid yield, % 95.3 95.1 94.6 95.5 90.1 94.6 Hydrogen consumption, % 3.25 3.31 3.42 3.26 3.65 3.53

Claims

1. A hydrocracking catalyst, characterized in that: Based on the weight of the final hydrocracking catalyst, the hydrocracking catalyst contains 20 - 70 wt% of modified Y zeolite, 3 - 35 wt% of hydro-metallic oxide, the total pore volume of the modified Y zeolite is 0.50 - 0.62 mL / g, and the mesopore volume accounts for 40 - 65% of the total pore volume; the relative crystallinity of the modified Y zeolite is 90 - 96%; The preparation method of the hydrocracking catalyst includes the following steps: (1) Prepare high-silica-alumina ratio nano-cluster Y zeolite; (2) After ammonium exchange of the high-silica-alumina ratio nano-cluster Y zeolite in step (1), hydrothermal treatment and acid treatment are carried out in sequence; (3) Use the zeolite treated in step (2) as the acidic cracking component to prepare the final hydrocracking catalyst; In step (1), the preparation of the high-silica-alumina ratio nano-cluster Y zeolite uses fatty alcohol polyoxyethylene ether sulfate as a template agent.

2. The catalyst according to claim 1, characterized in that: Based on the weight of the final hydrocracking catalyst, the hydrocracking catalyst contains 40 - 60 wt% of modified Y zeolite, 5 - 25 wt% of hydro-metallic oxide, the total pore volume of the modified Y zeolite is 0.55 - 0.60 mL / g, and the mesopore volume accounts for 52 - 62% of the total pore volume; the relative crystallinity of the modified Y zeolite is 92 - 95%.

3. The catalyst according to claim 1, characterized in that: The hydrocracking catalyst contains one or more of alumina and amorphous silica-alumina.

4. The catalyst according to claim 1, characterized in that: The hydro-metal is a Group VIB metal and / or a Group VIII metal.

5. The catalyst according to claim 4, characterized in that: The Group VIB metal is Mo and / or W; the Group VIII metal is Co and / or Ni. Based on the weight of the final hydrocracking catalyst, the content of Group VIB metal oxide is 5 - 17 wt%, and the Group VIII metal oxide is 1 - 8 wt%.

6. The catalyst according to claim 1, characterized in that: The silica-alumina ratio of the modified Y zeolite is 8 - 50; the unit cell constant of the modified zeolite is 24.25 - 24.51 Å.

7. The catalyst according to claim 6, characterized in that: The silica-alumina ratio of the modified Y zeolite is 12 - 25; the unit cell constant of the modified zeolite is 24.31 - 24.43 Å.

8. The catalyst according to claim 1, characterized in that: The specific surface area of the modified Y zeolite is 600-880 m 2 / g; the pyridine infrared acid content of the modified Y zeolite is 0.10-1.20 mmol / g; the Na 2 O content in the modified Y zeolite is 0.03-0.30 wt%.

9. The catalyst according to claim 8, characterized in that: The specific surface area of the modified Y zeolite is 750 - 850 m 2 / g; the pyridine infrared acid content of the modified Y zeolite is 0.50 - 1.00 mmol / g.

10. The preparation method of the hydrocracking catalyst according to any one of claims 1 to 9, characterized in that: The method includes the following steps: (1) Prepare high-silica-alumina ratio nano-cluster Y zeolite; (2) After ammonium exchange of the high-silica-alumina ratio nano-cluster Y zeolite in step (1), hydrothermal treatment and acid treatment are carried out in sequence; (3) Use the zeolite treated in step (2) as the acidic cracking component to prepare the final hydrocracking catalyst.

11. The method according to claim 10, characterized in that: The high-silica-alumina ratio nano-cluster Y-type molecular sieve prepared in step (1) has a silica-alumina molar ratio of 5.5 - 7.

5.

12. According to the method described in claim 11, it is characterized in that: The high-silica-alumina ratio nano-cluster Y-type molecular sieve prepared in step (1) has a silica-alumina molar ratio of 6.5 - 7.

0.

13. According to the method described in claim 10, it is characterized in that: The nano-cluster Y-type molecular sieve in step (1) is an aggregate formed by clustering of small crystal grains, the size of the nano-crystals is 80 - 150 nm; the size of the nano-clusters is 1.0 μm - 3.0 μm.

14. According to the method described in claim 13, it is characterized in that: The nano-cluster Y-type molecular sieve in step (1) is an aggregate formed by clustering of small crystal grains, the size of the nano-crystals is 100 - 130 nm; the size of the nano-clusters is 1.2 μm - 1.8 μm.

15. According to the method described in claim 10, it is characterized in that: The specific surface area of the molecular sieve described in step (1) is 800 - 920 m 2 / g, and the external specific surface area is 80 - 130 m 2 / g.

16. According to the method described in claim 15, it is characterized in that: The specific surface area of the molecular sieve described in step (1) is 840 - 880 m 2 / g, and the external specific surface area is 100 - 120 m 2 / g.

17. According to the method described in claim 10, it is characterized in that: The high-silica-alumina ratio nano-cluster Y-type molecular sieve prepared in step (1), after ammonium exchange, is hydrothermally treated at 600 °C and 0.1 MPa for 2 h. The relative crystallinity of the hydrothermally treated Y-type molecular sieve is 80 - 92%, and the crystallinity retention rate compared with the high-silica-alumina ratio nano-cluster Y-type molecular sieve before hydrothermal treatment is 80 - 93%.

18. According to the method described in claim 17, it is characterized in that: The relative crystallinity of the hydrothermally treated Y-type molecular sieve is 83 - 88%.

19. According to the method described in claim 10, it is characterized in that: The preparation of the high-silica-alumina ratio nano-cluster Y-type molecular sieve in step (1) uses fatty alcohol polyoxyethylene ether sulfate as a template agent.

20. According to the method described in claim 19, it is characterized in that: In step (1), the fatty alcohol polyoxyethylene sulfate has the molecular formula RO(CH 2 CH 2 O) n -SO 3 M, where R is an alkyl group, which is one or more of dodecyl, tridecyl, tetradecyl, and pentadecyl; n is the degree of polymerization, and n is an integer greater than 1; M is a cation.

21. According to the method described in claim 10, it is characterized in that: In step (1), the preparation of the high-silica-alumina ratio nano-cluster Y-type molecular sieve includes the following: a mixed material containing an alkali source, an aluminum source, a silicon source, and fatty alcohol polyoxyethylene ether sulfate is crystallized, washed, filtered, dried, and calcined to obtain the final high-silica-alumina ratio nano-cluster Y-type molecular sieve.

22. According to the method described in claim 21, it is characterized in that: When calculating the dosage of silicon source in terms of SiO 2 , the molar ratio of fatty alcohol polyoxyethylene ether sulfate / SiO 2 in the mixed material is 0.05 - 0.25; the molar ratio of materials in the mixed material is: Al 2 O 3 :(9.0 - 16.0)SiO 2 :(4.0 - 7.0)Na 2 O:(150 - 350)H 2 O:(0.5 - 3.0) fatty alcohol polyoxyethylene ether sulfate.

23. According to the method described in claim 22, it is characterized in that: When calculating the addition amount of silicon source by SiO 2 , the molar ratio of fatty alcohol polyoxyethylene ether sulfate / SiO 2 in the mixed material is 0.10 - 0.20; the molar ratio of materials in the mixed material is: Al 2 O 3 :(11.0 - 14.0)SiO 2 :(5.0 - 6.0)Na 2 O:(200 - 280)H 2 O:(1.0 - 2.0) fatty alcohol polyoxyethylene ether sulfate.

24. According to the method described in claim 21, it is characterized in that: The crystallization temperature is 90 - 110 °C; the crystallization time is 40 - 90 h.

25. According to the method described in claim 24, it is characterized in that: The crystallization temperature is 95 - 105 °C; the crystallization time is 50 - 70 h.

26. According to the method described in claim 24, it is characterized in that: First, it is crystallized at 20 - 50 °C for 20 - 40 h; then it is crystallized at 90 - 110 °C for 40 - 90 h.

27. According to the method described in claim 26, it is characterized in that: First, it is crystallized at 30 - 45 °C for 20 - 40 h; then it is crystallized at 95 - 105 °C for 50 - 70 h.

28. According to the method described in claim 21, it is characterized in that: The drying temperature is 100 - 120 °C, the time is 7 - 13 h, the calcination temperature is 450 - 550 °C, and the time is 4 - 6 h.

29. According to the method described in claim 10, it is characterized in that: In step (2), the ammonium salt used for ammonium exchange is one or more of ammonium nitrate, ammonium chloride, ammonium sulfate, ammonium acetate, and ammonium oxalate. The ammonium exchange temperature is 40 - 96 °C, the number of exchange times is 2 - 4 times, the ammonium salt concentration is 0.5 mol / L - 3.0 mol / L, and the solid-liquid ratio of ammonium exchange is 1:5 - 1:

20.

30. According to the method described in claim 29, it is characterized in that: The ammonium exchange temperature is 70 - 90 °C, and the solid-liquid ratio of ammonium exchange is 1:8 - 1:

15.

31. According to the method described in claim 10, it is characterized in that: In step (2), the hydrothermal treatment temperature is 500 - 700 °C; the hydrothermal pressure is 0.05 - 0.20 MPa; the hydrothermal treatment time is 1 - 10 h.

32. According to the method described in claim 31, it is characterized in that: In step (2), the hydrothermal treatment temperature is 550 - 650 °C; the hydrothermal pressure is 0.08 - 0.15 MPa; the hydrothermal treatment time is 2 - 4 h.

33. According to the method described in claim 10, it is characterized in that: In the solution used for acid treatment in step (2), the acid concentration of the acid is 0.1 - 2.5 mol / L.

34. According to the method described in claim 33, it is characterized in that: In the solution used for acid treatment in step (2), the acid concentration of the acid is 0.5 - 2.0 mol / L.

35. According to the method described in claim 10, it is characterized in that: In step (2), the acid treatment temperature is 20 - 90 °C, the acid treatment time is 0.5 - 6 h, and the solid-liquid volume ratio during acid treatment is 1:5 - 1:

20.

36. According to the method described in claim 35, it is characterized in that: In step (2), the acid treatment temperature is 40 - 70 °C, the acid treatment time is 2 - 3 h, and the solid-liquid volume ratio during acid treatment is 1:10 - 1:

15.

37. According to the method described in claim 10, it is characterized in that: In step (3), the catalyst is prepared by the kneading method or the impregnation method.

38. The hydrocracking catalyst according to any one of claims 1 to 9 is used for the hydrocracking reaction of catalytic diesel, it is characterized in that: The reaction conditions are as follows: the reaction temperature is 350~430°C, the reaction pressure is 4~10 MPa, the reaction volume space velocity is 0.5~2.0 h -1 , and the hydrogen-oil ratio is 800:1~1400:1.

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