Hydrocracking catalyst as well as preparation method and application thereof
By preparing a hydrocracking catalyst based on a KIT-6 and Y molecular sieve composite, the diffusion and stability issues of microporous and mesoporous molecular sieves were solved, thereby improving the cracking performance of the catalyst and the yield of jet fuel.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- PETROCHINA CO LTD
- Filing Date
- 2024-11-20
- Publication Date
- 2026-05-22
AI Technical Summary
Existing hydrocracking catalysts have shortcomings in their cracking effect. In particular, the long and narrow channels of microporous molecular sieves make it difficult for reactants to diffuse, while the poor structural stability of mesoporous molecular sieves affects their catalytic performance.
A hydrocracking catalyst with a plate-like metal particle structure was prepared by combining KIT-6 molecular sieve with Y molecular sieve, and then combining it with porous carbon black, macroporous alumina, boric acid and cellulose. This process was followed by crystallization and calcination to improve the synergistic effect between the metal active center and the support.
It improved the contact efficiency of macromolecular organics, reduced the steric hindrance of active centers, enhanced the selectivity of hydrocracking reactions, and achieved a high yield of jet fuel products.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of hydrocracking, specifically relating to a hydrocracking catalyst, its preparation method, and its application. Background Technology
[0002] Molecular sieves, due to their unique pore structure, are widely used in adsorption, separation, and catalysis, especially in the petrochemical industry. With the continuous expansion of molecular sieve catalytic applications, single-channel molecular sieves can no longer meet the diverse needs of catalyst preparation. Microporous molecular sieves excel in heterogeneous catalysis applications primarily due to their strong acidity and high structural stability. However, because microporous molecular sieves generally have small pore sizes and long, narrow channels, it is difficult for large molecules in reactants, such as heavy oil, to diffuse into the pores. This reduces the utilization rate of acidic sites within the microporous molecular sieve channels. Simultaneously, the narrow, long channels result in significant diffusion resistance, hindering the rapid diffusion and overflow of reaction product molecules, potentially leading to deep cracking and coking. While mesoporous molecular sieves can compensate for the diffusion limitations of microporous molecular sieves within reactants and products, their structural stability is often poor, further limiting their catalytic applications. Microporous-mesoporous composite molecular sieve materials can produce good synergistic effects and catalytic performance by combining the strengths and weaknesses of several individual materials, making their overall performance superior to that of the original constituent materials. This type of molecular sieve with multiple structures and superimposed functions can avoid the defects of single pore structures. The multi-level pore system can provide pores of different sizes at the same time, which will be of great help in solving problems such as mass transfer of macromolecules.
[0003] CN111484037A discloses a method for synthesizing SSZ-13 molecular sieves with different silica-to-alumina ratios via Y-type molecular sieve crystallization. The method uses TMADaOH as a structure-directing agent. An alkali source, silicon source, structure-directing agent, mesoporous template agent, and water are mixed uniformly. Different amounts of aluminum source are added to prepare a sol, and then Y-type molecular sieves are added to obtain an initial gel. A hydrothermal crystallization reaction is then carried out. After the reaction is complete, the crystallization product is obtained, cooled, washed to neutral, and dried to obtain molecular sieve powder. The molecular sieve powder is then calcined to obtain SSZ-13 molecular sieves with different silica-to-alumina ratios. The SSZ-13 molecular sieves obtained by this method have relatively low pore size and pore volume.
[0004] CN106311319A discloses a hydrocracking catalyst containing a micro-mesoporous composite molecular sieve and its application. The catalyst includes a catalyst support and active components. By weight percentage, the catalyst support comprises 5-50 wt% micro-mesoporous composite molecular sieve, 5-30 wt% Y microporous molecular sieve, 10-50 wt% alumina, 20-55 wt% porous carbon black, 5-25 wt% binder, and 1-5 wt% extrusion aid. By weight percentage, the active components comprise 10%-40% group VIB metal oxides, 1%-20% group VIII metal oxides, and / or 0.1%-10% group VA oxides. Although the catalyst contains 5-50 wt% Beta / KIT-6 micro-mesoporous composite molecular sieve, both are relatively weak in acid strength because Beta molecular sieve is a microporous molecular sieve with isomerization and KIT-6 mesoporous molecular sieve is an all-silica molecular sieve. Therefore, the hydrocracking catalytic effect needs to be enhanced.
[0005] Therefore, further research is needed in this field on hydrocracking catalysts. Summary of the Invention
[0006] The main objective of this invention is to provide a hydrocracking catalyst, its preparation method, and its application, so as to overcome the defects of poor cracking effect of existing hydrocracking catalysts.
[0007] To achieve the above objectives, the present invention provides a method for preparing a hydrocracking catalyst, comprising the following steps:
[0008] Step 1: KIT-6 molecular sieve, rare earth compound, titanium compound, hydrogenated active metal precursor, first template agent and water are mixed, crystallized and calcined to obtain composite material;
[0009] Step 2: Mix the composite material, Y molecular sieve directing agent, aluminum source, alkali source, silicon source and water, crystallize and calcine to obtain micro-mesoporous molecular sieve composite material;
[0010] Step 3: The micro-mesoporous molecular sieve composite material, porous carbon black, macroporous alumina, boric acid, cellulose and binder are mixed, shaped and calcined to obtain the catalyst support;
[0011] Step 4: Mix the aqueous solution of the active component with the catalyst support, and crystallize at a temperature of 120-170℃ and a pressure of 2-12MPa for 4-10 hours to obtain the hydrocracking catalyst.
[0012] The method for preparing the hydrocracking catalyst of the present invention, wherein the active component is a precursor of a Group VIB metal and / or a precursor of a Group VIII metal; the active component is at least one of a molybdenum precursor, a tungsten precursor, a nickel precursor, and a cobalt precursor; and the mass content of the active component, calculated as a metal oxide, is 23-26 wt%.
[0013] The preparation method of the hydrocracking catalyst of the present invention, wherein the mass ratio of the micro-mesoporous molecular sieve composite material, porous carbon black, macroporous alumina, boric acid, cellulose and binder is (50-70):(10-30):(10-30):(1-5):(1-5):(14-20); the amount of Brønsted acid in the hydrocracking catalyst support is 0.5-0.7 mmol / g and the amount of Lønsted acid is 0.6-0.8 mmol / g.
[0014] The method for preparing the hydrocracking catalyst of the present invention includes step 1, in which KIT-6 molecular sieve, rare earth compound, titanium compound and water are first mixed and crystallized to obtain a first crystallized product. Then the first crystallized product, hydrogenation active metal precursor, first template agent and water are mixed, crystallized and calcined to obtain the composite material.
[0015] The method for preparing the hydrocracking catalyst of the present invention, wherein in step 1, the rare earth compound is a rare earth salt, the titanium compound is at least one of titanium oxynitrate and titanium sulfate, the hydrocracking active metal precursor is a Group VIB metal precursor and / or a Group VIII metal precursor, and the first template agent is at least one of PVP, urea and hexadecyltrimethylammonium bromide.
[0016] The preparation method of the hydrocracking catalyst of the present invention includes a crystallization temperature of 90-100℃ and a crystallization time of 24-48 hours in step 2; after crystallization, an ammonium ion exchange step is also included, followed by calcination and steam treatment at a temperature of 800-900℃.
[0017] To achieve the above objectives, the present invention also provides a hydrocracking catalyst obtained by the above preparation method.
[0018] To achieve the above objectives, the present invention further provides the application of the aforementioned hydrocracking catalyst in the preparation of jet fuel, wherein the hydrocracking catalyst is used at a reaction pressure of 13–15 MPa, a hydrogen-to-oil volume ratio of 1300–1500, and a volume hourly space velocity of 1.3–1.5 h⁻¹. -1 When used in petroleum hydrocracking at a reaction temperature of 370–380℃, it can produce more jet fuel.
[0019] The beneficial effects of this invention are:
[0020] This invention mixes an aqueous solution of a metal active component with a molecular sieve composite material support having a micro-mesoporous structure. Through crystallization, the metal oxide is uniformly grown into the pores of the support, generating a hydrocracking catalyst with a lamellar metal particle structure. This enhances the synergistic effect between the metal hydrogenation centers and the cracking centers on the support, facilitates contact with macromolecular organic matter, reduces steric hindrance of the active centers, and improves the selectivity of jet fuel in the hydrocracking reaction process. Therefore, the hydrocracking catalyst of this invention exhibits good selective hydrocracking performance for low-grade distillate oils, enabling higher production of jet fuel with a higher yield. Detailed Implementation
[0021] The technical solution of the present invention will be described in detail below. The following embodiments are implemented under the premise of the technical solution of the present invention and a detailed implementation process is given. However, the protection scope of the present invention is not limited to the following embodiments. Structures or experimental methods that do not specify specific conditions in the following embodiments are generally performed under conventional conditions.
[0022] This invention provides a method for preparing a hydrocracking catalyst, comprising the following steps:
[0023] Step 1: KIT-6 molecular sieve, rare earth compound, titanium compound, hydrogenated active metal precursor, first template agent and water are mixed, crystallized and calcined to obtain composite material;
[0024] Step 2: Mix the composite material, Y molecular sieve directing agent, aluminum source, alkali source, silicon source and water, crystallize and calcine to obtain micro-mesoporous molecular sieve composite material;
[0025] Step 3: The micro-mesoporous molecular sieve composite material, porous carbon black, macroporous alumina, boric acid, cellulose and binder are mixed, shaped and calcined to obtain the catalyst support;
[0026] Step 4: Mix the aqueous solution of the active component with the catalyst support, and crystallize at a temperature of 120-170℃ and a pressure of 2-12MPa for 4-10 hours to obtain the hydrocracking catalyst.
[0027] In one embodiment, the crystallization temperature in step 1 is 100–190°C, the pressure is 1–13 MPa, and the time is 2–10 h.
[0028] In one embodiment, in step 1, KIT-6 molecular sieve, rare earth compound, titanium compound and water are first mixed and crystallized to obtain a first crystallized product. Then the first crystallized product, hydrogenated active metal precursor, first template agent and water are mixed, crystallized and calcined to obtain the composite material.
[0029] In another embodiment, the KIT-6 molecular sieve, rare earth compound, titanium compound, and water are mixed by atomizing the mixture, allowing the KIT-6 molecular sieve to adsorb the atomized droplets. In yet another embodiment, the mixture of rare earth compound and water is first atomized, and the KIT-6 molecular sieve adsorbs the atomized droplets; then the mixture of titanium compound and water is atomized, and the KIT-6 molecular sieve continues to adsorb the atomized droplets. Next, crystallization is performed to obtain a first crystallized product. The crystallization temperature is, for example, 100–150°C, the pressure is 1–5 MPa, and the time is 2–10 h.
[0030] In one embodiment, a first crystallizer, a hydrogenated active metal precursor, a first template agent, and water are mixed and crystallized at a temperature of 120–190°C and a pressure of 2–13 MPa for 2–10 hours, and calcined at a temperature of 500–550°C in an air atmosphere to obtain the composite material. This composite material has a lamellar structure.
[0031] This invention does not specifically limit the source and preparation method of KIT-6 molecular sieve; it can be a commercially available product or prepared according to existing technical methods.
[0032] In one embodiment, the rare earth compound is a rare earth salt, specifically a water-soluble rare earth salt. The rare earth element is preferably cerium, lanthanum, or praseodymium. The rare earth salt can be one or more of cerium nitrate, lanthanum nitrate, and praseodymium nitrate.
[0033] In one embodiment, the titanium-containing compound is titanium oxynitrate or titanium sulfate.
[0034] In one embodiment, the hydrogenating active metal in the hydrogenating active metal precursor is a Group VIB metal and / or a Group VIII metal, preferably molybdenum, tungsten, nickel, or cobalt. The hydrogenating active metal precursor can be a hydrogenating active metal salt, such as a nitrate, or a salt formed by the hydrogenating active metal as an anion, preferably ammonium heptamolybdate, ammonium metatungstate, nickel nitrate, or cobalt nitrate.
[0035] In one embodiment, the first template agent is at least one of PVP, urea, and hexadecyltrimethylammonium bromide.
[0036] In one embodiment, the rare earth compound is calculated as rare earth oxide, the titanium compound is calculated as titanium dioxide, the hydrogenated active metal precursor is calculated as hydrogenated active metal oxide, and the mass ratio of KIT-6 molecular sieve: rare earth oxide: titanium dioxide: metal oxide: first template agent: water is 1:(0.01-0.12):(0.01-0.15):(0.10-0.30):(0.01-0.03):(0.50-1.5), preferably 1:(0.03-0.10):(0.05-0.10):(0.20-0.30):(0.015-0.02):(0.7-1.0).
[0037] Step 2 of this invention is as follows: the above-prepared composite material, Y molecular sieve directing agent, aluminum source, alkali source, silicon source and water are mixed, crystallized and calcined to obtain micro-mesoporous molecular sieve composite material.
[0038] In one embodiment, the crystallization temperature in step 2 is 90-100°C, and the crystallization time is 24-48 hours. After crystallization, an ammonium ion exchange step is included, followed by calcination. After calcination, a steam treatment step is also included. Specifically, after crystallization, the mixture is filtered, then subjected to ion exchange in a 1-2 mol / L ammonium sulfate aqueous solution, dried, calcined, and steam treated to obtain a micro-mesoporous molecular sieve composite material. In one embodiment, the steam treatment temperature is 800-900°C, preferably 830-880°C.
[0039] In one embodiment, the aluminum source is calculated as Al2O3, the alkali source as Na2O, and the silicon source as SiO2. The mass ratio of each substance in step 2 is: (0.5-1.5) composite material : (0.06-1.7) Y molecular sieve directing agent : 1 Al2O3 : (0.06-1.2) Na2O : (2.0-3.5) SiO2 : (10-50) H2O. The aluminum source can be at least one of aluminum sulfate and sodium aluminate, the alkali source can be at least one of sodium aluminate and potassium hydroxide, and the silicon source can be at least one of water glass and silica sol.
[0040] In one embodiment, the Y-zeolite directing agent of the present invention can be prepared by the following method:
[0041] The alkali source, aluminum source, silicon source and water are mixed and aged to obtain Y molecular sieve directing agent.
[0042] The alkali source can be at least one of sodium aluminate and potassium hydroxide, the aluminum source can be at least one of aluminum sulfate and sodium aluminate, and the silicon source can be at least one of water glass and silica sol. The molar ratio of the alkali source, aluminum source, silicon source, and water can be (6-8.5)Na₂O:1Al₂O₃:(7-13)SiO₂:(200-350)H₂O (the alkali source is calculated as Na₂O, the aluminum source as Al₂O₃, and the silicon source as SiO₂), preferably (6.5-7.5)Na₂O:1Al₂O₃:(9-11)SiO₂:(220-300)H₂O. The aging temperature is 20-60℃, preferably 25-40℃.
[0043] The micro-mesoporous molecular sieve composite material obtained by the method of this invention has a specific surface area of 630-690 m². 2 / g, total pore volume is 0.9-1.20mL / g, pore size distribution is 4-60nm, Brønsted acid content is 0.8-1.3mmol / g, L-acid content is 0.6-0.9mmol / g.
[0044] Step 3 of this invention is as follows: the micro-mesoporous molecular sieve composite material, porous carbon black, macroporous alumina, boric acid, cellulose and aluminum phosphate sol are mixed, shaped and calcined to obtain the catalyst support.
[0045] In one embodiment, the binder can be aluminum phosphate sol. A mixture of solid materials—micro-mesoporous molecular sieve composite material, porous carbon black, macroporous alumina, boric acid, and cellulose—is uniformly mixed to obtain a mixture. The aluminum phosphate sol is then atomized into micron-sized droplets. The mixture is then allowed to adsorb these droplets, shaped, and calcined to obtain a catalyst support. Specifically, the aluminum phosphate sol can be atomized into micron-sized droplets by pressurizing and spraying the sol, followed by impacting the sol with gas in a perpendicular spray direction, causing it to atomize into micron-sized droplets.
[0046] In one embodiment, the mass ratio of the micro-mesoporous molecular sieve composite material, porous carbon black, macroporous alumina, boric acid, cellulose, and aluminum phosphate sol is (50–70):(10–30):(10–30):(1–5):(1–5):(14–20). The amount of Brønsted acid in the hydrocracking catalyst support is 0.5–0.7 mmol / g, and the amount of Lewis acid is 0.6–0.8 mmol / g.
[0047] Step 4 of this invention involves mixing the aqueous solution of the active component with the catalyst support and crystallizing it for 4-10 hours at a temperature of 120-170°C and a pressure of 2-12 MPa to obtain a hydrocracking catalyst.
[0048] In one embodiment, the active component is loaded onto the catalyst support by: forming an active component solution with a second template agent; adsorbing the active component solution onto the catalyst support; crystallizing; and calcining to obtain a hydrocracking catalyst. The crystallization temperature is 120–170°C, the pressure is 2–12 MPa, and the crystallization time is 4–10 h. Then, calcination is performed at a temperature of 500–550°C.
[0049] In one embodiment, the active component is a precursor of a Group VIB metal and / or a Group VIII metal, preferably molybdenum, tungsten, nickel, or cobalt. The precursor can be a metal salt, such as a nitrate, or a salt formed by the metal as an anion, preferably ammonium heptamolybdate, ammonium metatungstate, nickel nitrate, or cobalt nitrate. In another embodiment, the active component in the hydrocracking catalyst has a mass content of 23–26 wt% based on metal oxides.
[0050] In one embodiment, the second template agent in step 4 is at least one of PVP, urea, and hexadecyltrimethylammonium bromide, and the content of the second template agent in the active component solution is 0.1 to 0.5 wt%.
[0051] The hydrocracking catalyst obtained by the method of this invention has a specific surface area of 350–420 m². 2 With a pore volume of 0.35–0.6 mL / g and suitable acidity, it can be used in petroleum hydrocracking, such as for the hydrocracking of wax oil and diesel oil, resulting in a high yield of aviation kerosene.
[0052] The technical solution of the present invention will be further described in detail below through specific embodiments.
[0053] Example 1
[0054] 1. The preparation method of micro-mesoporous molecular sieve composite materials is as follows:
[0055] (1) 87g of sodium aluminate solution (Al2O3 content is 4wt%, Na2O content is 20wt%) and 130g of water glass solution (SiO2 content is 20wt%) were added sequentially to 35g of deionized water (i.e. 8.5Na2O:1Al2O3:11.8SiO2:322H2O) and aged at 20℃ for 24h to obtain Y molecular sieve directing agent.
[0056] (2) According to the mass ratio of KIT-6 molecular sieve: rare earth oxide: TiO2: metal oxide: template agent: water = 1:0.01:0.01:0.1:0.01:0.5, KIT-6 molecular sieve was atomized and adsorbed with cerium nitrate and titanium oxynitrate aqueous solution. It was crystallized for 10 h at 100℃ and 1 MPa to obtain mixture A. Mixture A was mixed evenly with ammonium heptamolybdate, nickel nitrate and PVP. It was crystallized for 10 h at 120℃ and 2 MPa. After calcination at 550℃, rare earth oxide / TiO2 / metal oxide / KIT-6 mesoporous molecular sieve composite material B with plate-like structure was obtained.
[0057] (3) 15g of mesoporous molecular sieve composite material B, 5g of Y molecular sieve directing agent, 75g of aluminum sulfate solution (Al2O3 content of 2wt%), and 78g of sodium aluminate solution (Al2O3 content of 5wt% and Na2O content of 5wt%) were added to 96g of water glass solution (SiO2 content of 20wt%). After stirring evenly, 5g of deionized water was added to prepare mixture C. Mixture C was crystallized at 100℃ for 24h to obtain a slurry of Y / rare earth oxide / TiO2 / metal oxide / KIT-6 micro-mesoporous molecular sieve composite material. After filtration, it was ion exchanged in 1mol / L ammonium sulfate aqueous solution for 1 hour, dried at 100℃ for 1 hour, and treated with water vapor at 900℃ for 2.0 hours to obtain Y / rare earth oxide / TiO2 / metal oxide / KIT-6 micro-mesoporous molecular sieve composite material.
[0058] 2. According to the mass ratio of micro-mesoporous molecular sieve composite material: porous carbon black: macroporous alumina: boric acid: organic macromolecular cellulose: aluminum phosphate sol (70%): (3%): (7%): (1%): (1%): (18%), the solid materials are mixed evenly, and then 18wt% aluminum phosphate sol is pressurized to 1.5MPa and sprayed out, and then passed through a flow rate perpendicular to the spray direction at 8m 3 A high-speed gas stream of [speed value] / min is ejected and impacts the solid mixture, creating a humid atmosphere that allows for thorough and uniform adsorption. The mixture is then rolled, shaped, and calcined to obtain the support. An aqueous solution of a metal salt (22 wt% ammonium heptamolybdate, 3 wt% nickel nitrate, and 0.1 wt% PVP) is prepared and mixed with the support for adsorption. The mixture is then crystallized at 120°C and 2 MPa for 10 hours, followed by calcination at 550°C to obtain the hydrocracking catalyst.
[0059] Example 2
[0060] 1. The preparation method of micro-mesoporous molecular sieve composite materials is as follows:
[0061] (1) 77g of sodium aluminate solution (Al2O3 content of 4wt%, Na2O content of 20wt%) and 105g of water glass solution (SiO2 content of 20wt%) were added sequentially to 67g of deionized water (i.e. 6.82Na2O:1Al2O3:11.81SiO2:323H2O), and aged at 20℃ for 24h to obtain Y molecular sieve directing agent.
[0062] (2) According to the mass ratio of KIT-6 molecular sieve: rare earth oxide: TiO2: metal oxide: template agent: water = 1:0.06:0.075:0.15:0.015:1, KIT-6 molecular sieve was atomized and adsorbed with cerium nitrate and titanium oxynitrate aqueous solution. It was crystallized for 5h at 125℃ and 2.5MPa to obtain mixture A. Mixture A was mixed evenly with ammonium metatungstate, nickel nitrate and urea. It was crystallized for 5h at 140℃ and 8MPa. After calcination at 500℃, rare earth oxide / TiO2 / metal oxide / KIT-6 mesoporous molecular sieve composite material B with plate-like structure was obtained.
[0063] (3) 18g of mesoporous molecular sieve composite material B, 8g of Y molecular sieve directing agent, 65g of aluminum sulfate solution (Al2O3 content of 2wt%), and 65g of sodium aluminate solution (Al2O3 content of 5wt% and Na2O content of 5wt%) were added to 75g of water glass solution (SiO2 content of 20wt%). After stirring evenly, 50g of deionized water was added to prepare mixture C. Mixture C was crystallized at 90℃ for 48h to obtain a slurry of Y / rare earth oxide / TiO2 / metal oxide / KIT-6 micro-mesoporous molecular sieve composite material. After filtration, it was ion exchanged in 1.5mol / L ammonium sulfate aqueous solution for 1 hour, dried at 100℃ for 1 hour, and treated with water vapor at 850℃ for 1.5 hours to obtain Y / rare earth oxide / TiO2 / metal oxide / KIT-6 micro-mesoporous molecular sieve composite material.
[0064] 2. According to the mass ratio of micro-mesoporous molecular sieve composite material: porous carbon black: macroporous alumina: boric acid: organic macromolecular cellulose: aluminum phosphate sol (60%): (10%): (12%): (2%): (1%): (15%), the solid materials are mixed evenly, and then 15wt% aluminum phosphate sol is sprayed out after being pressurized to 2.5MPa, and then passed through a flow rate of 12m perpendicular to the spray direction. 3A high-speed gas stream of [speed value] / min is ejected and impacts the solid mixture, creating a humid atmosphere that allows for thorough and uniform adsorption. The mixture is then rolled, shaped, and calcined to obtain the support. An aqueous solution of a metal salt (18 wt% ammonium heptamolybdate, 5 wt% nickel nitrate, and 0.25 wt% urea) is prepared and mixed with the support for adsorption. The mixture is then crystallized at 150°C and 7 MPa for 6 hours, followed by calcination at 530°C to obtain the hydrocracking catalyst.
[0065] Example 3
[0066] 1. The preparation method of micro-mesoporous molecular sieve composite materials is as follows:
[0067] (1) 65g of sodium aluminate solution (Al2O3 content is 4wt%, Na2O content is 20wt%) and 82g of water glass solution (SiO2 content is 20wt%) were added sequentially to 100g of deionized water (i.e. 6.2Na2O:1Al2O3:10.7SiO2:206H2O) and aged at 40℃ for 24h to obtain Y molecular sieve directing agent.
[0068] (2) According to the mass ratio of KIT-6 molecular sieve: rare earth oxide: TiO2: metal oxide: template agent: water = 1:0.12:0.15:0.3:0.03:1.5, KIT-6 molecular sieve was atomized and adsorbed with cerium nitrate and titanium sulfate aqueous solution. It was crystallized for 2 hours at 150℃ and 5MPa to obtain mixture A. Mixture A was mixed evenly with ammonium molybdate, cobalt nitrate and hexadecyltrimethylammonium bromide. It was crystallized for 5 hours at 160℃ and 11MPa. After calcination at 525℃, rare earth oxide / TiO2 / metal oxide / KIT-6 mesoporous molecular sieve composite material B with plate-like structure was obtained.
[0069] (3) 21g of mesoporous molecular sieve composite material B, 11g of Y molecular sieve directing agent, 70g of aluminum sulfate solution (Al2O3 content of 2wt%), and 41g of sodium aluminate solution (Al2O3 content of 5wt% and Na2O content of 5wt%) were added to 72g of water glass solution (SiO2 content of 20wt%). After stirring evenly, 82g of deionized water was added to prepare mixture C. Mixture C was crystallized at 95℃ for 36h to obtain a slurry of Y / rare earth oxide / TiO2 / metal oxide / KIT-6 micro-mesoporous molecular sieve composite material. After filtration, it was ion exchanged in 2mol / L ammonium sulfate aqueous solution for 0.5h, dried at 100℃ for 1h, and treated with water vapor at 800℃ for 1.0h to obtain Y / rare earth oxide / TiO2 / metal oxide / KIT-6 micro-mesoporous molecular sieve composite material.
[0070] 2. According to the mass ratio of micro-mesoporous molecular sieve composite material: porous carbon black: macroporous alumina: boric acid: organic macromolecular cellulose: aluminum phosphate sol (50%): (10%): (17%): (2%): (1%): (20%), the solid materials are mixed evenly, and then 20wt% aluminum phosphate sol is pressurized to 2MPa and sprayed out, and then passed through a flow rate of 10m perpendicular to the spray direction. 3 A high-speed gas stream of [speed value] / min is ejected and impacts the solid mixture, creating a humid atmosphere that allows for thorough and uniform adsorption. The mixture is then rolled, shaped, and calcined to obtain the support. An aqueous solution of a metal salt (18 wt% ammonium metatungstate, 8 wt% nickel nitrate, and 0.5 wt% hexadecyltrimethylammonium bromide) is prepared and mixed with the support for adsorption. The mixture is then crystallized at 170°C and 12 MPa for 4 hours, followed by calcination at 500°C to obtain the hydrocracking catalyst.
[0071] The specific surface area, pore volume, pore size distribution, and infrared acid content of the micro-mesoporous molecular sieve composite materials, hydrocracking catalyst supports, and hydrocracking catalysts of Examples 1-4 were tested respectively, and the results are shown in Tables 1-3.
[0072] Table 1 Properties of micro-mesoporous molecular sieve composites
[0073]
[0074] Table 2 Properties of catalyst supports
[0075]
[0076] Table 3 Properties of the catalyst
[0077]
[0078]
[0079] The hydrocracking catalysts prepared in Examples 1-4 were used in the hydrocracking reaction of high aromatic distillate oil. The properties of the high aromatic distillate oil are shown in Table 4, and the reaction conditions and evaluation results are shown in Table 5.
[0080] Table 4 Properties of High Aromatic Distillate Oils
[0081]
[0082] Table 5 Reaction conditions and evaluation results
[0083]
[0084]
[0085] As shown in Tables 1-3 and 5, the hydrocracking catalyst prepared by the method of the present invention has both micro and mesoporous structures, is suitable for acidity, and has good hydrogenation activity. When the hydrocracking catalyst of the present invention is used in the hydrocracking reaction of oil products, the yield of light oil is high and the yield of tail oil is low, which can achieve the production of more jet fuel products.
[0086] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.
Claims
1. A method for preparing a hydrocracking catalyst, characterized in that, Includes the following steps: Step 1: KIT-6 molecular sieve, rare earth compound, titanium compound, hydrogenated active metal precursor, first template agent and water are mixed, crystallized and calcined to obtain composite material; Step 2: Mix the composite material, Y molecular sieve directing agent, aluminum source, alkali source, silicon source and water, crystallize and calcine to obtain micro-mesoporous molecular sieve composite material; Step 3: The micro-mesoporous molecular sieve composite material, porous carbon black, macroporous alumina, boric acid, cellulose and binder are mixed, shaped and calcined to obtain the catalyst support; Step 4: Mix the aqueous solution of the active component with the catalyst support, and crystallize at a temperature of 120-170℃ and a pressure of 2-12MPa for 4-10 hours to obtain the hydrocracking catalyst.
2. The method for preparing the hydrocracking catalyst according to claim 1, characterized in that, The active component is a precursor of a Group VIB metal and / or a Group VIII metal.
3. The method for preparing the hydrocracking catalyst according to claim 2, characterized in that, The active component is at least one of the precursors of molybdenum, tungsten, nickel, and cobalt; the mass content of the active component, calculated as metal oxide, is 23-26 wt%.
4. The method for preparing the hydrocracking catalyst according to claim 1, characterized in that, The amount of Brønsted acid in the hydrocracking catalyst support is 0.5–0.7 mmol / g, and the amount of Lewis acid is 0.6–0.8 mmol / g.
5. The method for preparing the hydrocracking catalyst according to claim 1, characterized in that, The mass ratio of the micro-mesoporous molecular sieve composite material, porous carbon black, macroporous alumina, boric acid, cellulose and binder is (50-70): (10-30): (10-30): (1-5): (1-5): (14-20).
6. The method for preparing the hydrocracking catalyst according to claim 1, characterized in that, In step 1, KIT-6 molecular sieve, rare earth compound, titanium compound and water are first mixed and crystallized to obtain a first crystallized product. Then the first crystallized product, hydrogenated active metal precursor, first template agent and water are mixed, crystallized and calcined to obtain the composite material.
7. The method for preparing the hydrocracking catalyst according to claim 1, characterized in that, In step 1, the rare earth compound is a rare earth salt, the titanium compound is at least one of titanium oxynitrate and titanium sulfate, the hydrogenated active metal precursor is a Group VIB metal precursor and / or a Group VIII metal precursor, and the first template agent is at least one of PVP, urea, and hexadecyltrimethylammonium bromide.
8. The method for preparing the hydrocracking catalyst according to claim 1, characterized in that, Step 2 crystallization temperature is 90-100℃, crystallization time is 24-48 hours; after crystallization, there is also an ammonium ion exchange step, followed by calcination and steam treatment at a temperature of 800-900℃.
9. The hydrocracking catalyst obtained by the preparation method according to any one of claims 1-8.
10. The application of the hydrocracking catalyst according to claim 9 in the preparation of jet fuel products, characterized in that, The hydrocracking catalyst is used at a reaction pressure of 13–15 MPa, a hydrogen-to-oil volume ratio of 1300–1500, and a volume hourly space velocity of 1.3–1.5 h⁻¹. -1 When the reaction temperature is 370-380℃, it can be used for petroleum hydrocracking to produce more jet fuel.