A hydrocracking catalyst, its preparation method and use

Abstract

The application discloses a hydrocracking catalyst and a preparation method and application thereof. The catalyst comprises a hydrogenation active metal component and a carrier, and the carrier comprises a modified ZSM-22 molecular sieve and a Y molecular sieve. The Y molecular sieve has the following properties: a relative crystallinity of 110% to 150%, a molar ratio of SiO2 / Al2O3 of 10 to 100, preferably 15 to 70, a cell parameter of 2.425 to 2.445 nm, a total pore volume of 0.55 to 1.0 mL / g, preferably 0.6 to 1.0 mL / g, and a mesopore volume accounting for more than 70% of the total pore volume, preferably 80% to 90%. The preparation method of the hydrocracking catalyst comprises preparation of the carrier and loading of the hydrogenation active metal component. The hydrocracking catalyst can be used for production of a lubricating oil base oil raw material, and the obtained lubricating oil base oil raw material has the advantages of high viscosity index, low n-alkane content and good low-temperature flow performance.

Description

Technical Field

[0001] This invention relates to the field of hydrocracking, specifically to a hydrocracking catalyst, its preparation method, and its application. Background Technology

[0002] Hydrocracking technology, due to its strong adaptability to feedstocks, flexible operation, green and environmentally friendly production process, and high selectivity and quality of target products, has become one of the important processing methods for producing high-quality chemical feedstocks and clean fuel oils from low-quality petroleum feedstocks. During the hydrocracking reaction, the polycyclic aromatic hydrocarbons contained in the feedstock undergo hydrogenation saturation and ring-opening reactions, and the resulting alkanes are enriched in the tail oil product, which can be used as high-quality feedstocks for producing lubricating oil base oils.

[0003] Hydrocracking catalysts are bifunctional catalysts composed of an active metal as the hydrogenation component and an acidic molecular sieve or amorphous silica-alumina as the cracking component.

[0004] Y-type molecular sieves are the most commonly used cracking components in hydrocracking catalysts, exhibiting strong ring-opening conversion capabilities for polycyclic hydrocarbons, but their isomerization properties are weak. This results in a high content of straight-chain alkanes in the hydrocracking tail oil, affecting its low-temperature flow properties. Therefore, using molecular sieves with suitable cracking performance and strong isomerization properties as acid cracking components can enhance the catalyst's isomerization properties while ensuring its ring-opening conversion ability. This effectively reduces the n-alkane content in the hydrocracking tail oil, yielding lubricating oil base oil feedstocks with high viscosity index and good low-temperature flow properties.

[0005] The viscosity index of lubricating oil base oil is closely related to the structure and composition of its hydrocarbons. Cyclic hydrocarbons with long side chains and short-branched isoalkanes are ideal components of lubricating oil base oil. Although n-alkanes have a high viscosity index, their high pour point affects the low-temperature flow properties of lubricating oils, necessitating their conversion into isoalkanes.

[0006] CN102145307A discloses a method for producing high viscosity index lubricating oil base oil. This method uses a silicon-aluminum composite material as the cracking component of a cracking catalyst, which exhibits excellent hydrocracking activity and selectivity for middle distillate oils. However, due to the weak acidity of the silicon-aluminum composite material and low catalyst activity, the viscosity index of the lubricating oil base oil obtained through hydrocracking can only reach approximately 86.

[0007] US7300900B2 discloses a method for producing high viscosity index hydrocracking tail oil. The hydrocracking catalyst used in this method employs one or more molecular sieves such as ZBM-30, ZSM-48, and EU-1, along with Y molecular sieve, as a cracking component. Under the same process conditions, the viscosity index of the hydrocracking tail oil obtained is 5 units higher than that obtained by using only Y molecular sieve as a cracking component.

[0008] Both CN107344108A and CN106669801A use Y and ZSM-48 composite molecular sieves as the acidic component of the cracking catalyst. Through the modification of the molecular sieve, the prepared catalyst has good ring-opening conversion activity and isomerization performance, and can produce hydrocracking tail oil products with low straight-chain alkane content and high viscosity index as lubricating oil base oil feedstock. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides a hydrocracking catalyst, its preparation method, and its applications. The hydrocracking catalyst can be used to produce lubricating oil base oil feedstocks, which exhibit advantages such as high viscosity index, low n-alkane content, and good low-temperature flow properties.

[0010] A hydrocracking catalyst, comprising a hydrocracking active metal component and a support, wherein the support comprises modified ZSM-22 molecular sieve and Y molecular sieve; the Y molecular sieve has the following properties: relative crystallinity of 110%~150%, SiO2 / Al2O3 molar ratio of 10~100, preferably 15~70, cell parameter of 2.425~2.445 nm, total pore volume of 0.55~1.0 mL / g, preferably 0.6~1.0 mL / g, and mesoporous pore volume accounting for more than 70% of the total pore volume, preferably 80%~90%.

[0011] In the catalyst of this invention, the molar ratio of SiO2 / Al2O3 on the outer surface of the modified ZSM-22 molecular sieve is 500-1000, and the molar ratio of SiO2 / Al2O3 in the bulk phase is 50-150; the total pyridine infrared spectral acidity is 0.1-0.5 mmol / g, and the total pyridine infrared spectral acidity is 0.001-0.03 mmol / g; preferably, the molar ratio of SiO2 / Al2O3 on the outer surface of the modified ZSM-22 molecular sieve is 600-900, and the molar ratio of SiO2 / Al2O3 in the bulk phase is 60-120; the total pyridine infrared spectral acidity is 0.15-0.25 mmol / g; and the total pyridine infrared spectral acidity is 0.01-0.025 mmol / g.

[0012] In the catalyst of this invention, the specific surface area of ​​the hydrocracking catalyst is 250~450 m². 2 / g, with a pore volume of 0.30~0.60mL / g.

[0013] In the catalyst of this invention, based on the weight of the hydrocracking catalyst, the content of the active metal component for hydrocracking, calculated as oxide, is 14% to 38%, and the content of the support is 60% to 85%; based on the weight of the support, the content of modified ZSM-22 molecular sieve is 10% to 50%, and the content of Y molecular sieve is 10% to 40%.

[0014] In the catalyst of this invention, the support further contains macroporous alumina, with the macroporous alumina content ranging from 10% to 80% based on the weight of the support. The macroporous alumina has the following properties: pore volume of 0.7 to 1.0 mL / g and specific surface area of ​​200 to 500 m². 2 / g.

[0015] The catalyst of the present invention, the hydrocracking catalyst, further includes a binder, such as microporous alumina, and the content of the binder is 0.1% to 2% based on the weight of the catalyst.

[0016] In the catalyst of this invention, the hydrocracking catalyst contains a group VIB and / or group VIII metal, preferably molybdenum and / or tungsten, and preferably cobalt and / or nickel. Based on the weight of the catalyst, the content of group VIB metal (calculated as oxide) in the catalyst of this invention is 10.0% to 30.0%, and the content of group VIII metal (calculated as oxide) is 4.0% to 8.0%.

[0017] The preparation method of the above-mentioned hydrocracking catalyst includes the preparation of the support and the loading of the hydrogenation active metal component; wherein, the preparation process of the support is as follows: modified ZSM-22 molecular sieve, Y molecular sieve, and macroporous alumina are mixed, shaped, dried, and calcined to form the support; wherein, the preparation method of the modified ZSM-22 molecular sieve includes:

[0018] (1) Preparation of ZSM-22 molecular sieve without removal of template agent;

[0019] (2) Mix the ZSM-22 molecular sieve obtained in step (1) with a dealumination and silicon replenishment reagent to perform dealumination and silicon replenishment;

[0020] (3) Treat the material obtained in step (2) with steam;

[0021] (4) The material obtained in step (3) is treated with a buffer solution to obtain modified ZSM-22 molecular sieve.

[0022] Further, in step (1), the ZSM-22 molecular sieve without template removal can be prepared by hydrothermal synthesis. For example, silicon source, aluminum source, template agent, alkali source, and water are fed in the following molar ratio: SiO2: (0.006~0.03)Al2O3: (0.2~4.0)R (template agent): (0.01~10)K2O: (10~200)H2O. After the mixed material is crystallized at 150~180℃ for 2~5 days, the product is washed until the pH value is 7~8, then filtered and dried at 80~120℃ to obtain the ZSM-22 molecular sieve without template removal.

[0023] Furthermore, in the preparation process of the ZSM-22 molecular sieve, the silicon source is selected from one or more of silica sol, silica, tetraethyl orthosilicate, etc.; the aluminum source is selected from one or more of aluminum sulfate octadecyl water, aluminum isopropoxide, boehmite, potassium aluminate, etc.; the template agent is selected from one or more of 1,6-hexanediamine, n-butylamine, diethylamine, imidazole bisquaternary ammonium salts, etc.; the alkali source is potassium hydroxide; and the water is deionized water.

[0024] Further, in step (2), the dealuminizing and silicon replenishing reagent is at least one of ammonium hexafluorosilicate solution, tetraethyl orthosilicate solution, etc.

[0025] Further, in step (2), the molar concentration of the dealumination and silicon replenishment reagent is 0.5~1.5 mol / L. The mass ratio of the ZSM-22 molecular sieve obtained in step (1) to the dealumination and silicon replenishment reagent is 1:2~1:8.

[0026] Further, in step (2), the specific operation process of the dealuminization and silicon replenishment is as follows: after the ZSM-22 molecular sieve obtained in step (1) is mixed evenly with water, the temperature is raised to 60~100℃ and stirred continuously. The dealuminization and silicon replenishment reagent is added dropwise. After the addition is completed, stirring is continued for 60~120min. The mixture is filtered while hot, the resulting filter cake is washed with water, filtered again and dried. The liquid-solid volume ratio of water to the ZSM-22 molecular sieve obtained in step (1) is 2:1~8:1mL / g.

[0027] Further, in step (3), the conditions for steam treatment are: temperature of 400~700℃, preferably 500~600℃, pressure of 0.01~0.3MPa, preferably 0.1~0.2MPa, and time of 0.5~6h, preferably 1~4h.

[0028] Further, in step (4), the buffer solution is one or more of oxalic acid-ammonium oxalate solution and acetate-ammonium acetate solution. The pH value of the buffer solution is 4.5~6.5, preferably 5.0~6.0. The molar concentration of organic acid ions in the buffer solution is 0.1~1.0 mol / L. The liquid-solid volume ratio of the buffer solution to the material obtained in step (3) is 3:1~10:1 mL / g.

[0029] Further, in step (4), the specific processing procedure is as follows: the material obtained in step (3) is mixed with the buffer solution and stirred, the processing temperature is 40~80℃, and the processing time is 0.5~3h.

[0030] Further, in step (4), solid-liquid separation (e.g., vacuum filtration) is performed; and the above operation is repeated 2 to 4 times. The final material is dried to obtain the modified ZSM-22 molecular sieve.

[0031] In the method of the present invention, during the preparation of the carrier, the drying and calcination can be carried out under conventional conditions, generally drying at 100℃~150℃ for 1~12h, and then calcining at 450℃~550℃ for 3.0~6.0h.

[0032] In the method of the present invention, the Y molecular sieve can be prepared according to existing technology, such as the method according to CN201610289588.6.

[0033] In the method of this invention, the catalyst support is loaded with hydrogenation active metal components using conventional methods, such as kneading or impregnation. Preferred in this invention is the impregnation method for loading the hydrogenation active metal components, followed by drying and calcination to obtain the hydrocracking catalyst. The impregnation method can be saturated impregnation, excess impregnation, or complexation impregnation; that is, the catalyst support is impregnated with a solution containing the desired active component. The impregnated support is then dried at 100℃~150℃ for 1~12 h, and then calcined at 450℃~550℃ for 3.0~6.0 h to obtain the final catalyst.

[0034] A hydrocracking method, wherein the feedstock oil is reacted in the presence of the above-mentioned hydrocracking catalyst; the hydrocracking reaction conditions are as follows: reaction pressure of 12.0~18.0 MPa, temperature of 350~435℃, hydrogen-to-oil volume ratio of 1000:1~2000:1, and liquid hourly space velocity of 0.5~5.0 h⁻¹. -1 .

[0035] In the above-mentioned hydrocracking method, the feedstock oil is one or more of vacuum distillate oil, coking wax oil, solvent-refined deasphalted oil, and Fischer-Tropsch synthetic oil.

[0036] Compared with existing technologies, the hydrocracking catalyst, its preparation method, and its application of the present invention have the following advantages:

[0037] 1. The method for preparing modified ZSM-22 molecular sieve in this invention involves firstly, the molecular sieve obtained through hydrothermal synthesis does not undergo template removal treatment. The organic template molecules in the pores act as pore protectants. A dealumination and silicon replenishment method is used to specifically remove acidic centers on the outer surface of the molecular sieve, reducing excessive cracking reactions of n-alkanes on the outer surface. Under the action of the dealumination and silicon replenishment reagent, the aluminum on the outer surface of the molecular sieve is replaced by non-acidic silicon atoms. Due to the presence of template molecules, the acidic centers within the pores are protected. Subsequently, a constant-pressure, high-temperature steam treatment method is used to reduce the total acidity of the molecular sieve and simultaneously remove template molecules from the pores. Finally, a buffer solution is used to remove the non-framework aluminum generated during the hydrothermal treatment, making the pores of the molecular sieve more open and unobstructed, facilitating the diffusion of intermediate products during the shape-selective isomerization reaction of n-alkanes.

[0038] 2. The catalyst used in this invention employs a modified ZSM-22 molecular sieve, which has a low total infrared acidity of di-tert-butylpyridine. While eliminating acid sites on the outer surface, it also possesses an open and unobstructed pore structure, enhancing the isomerization properties of the molecular sieve. Using this modified ZSM-22 molecular sieve and Y molecular sieve together as cracking centers fully utilizes their individual performance characteristics and enables a synergistic catalytic effect. Specifically, the Y molecular sieve provides suitable cracking performance for the catalyst, enabling the ring-opening conversion of cyclic hydrocarbons into chain hydrocarbons, while the ZSM-22 molecular sieve enhances the isomerization properties of the catalyst, converting n-alkanes into isoalkanes. The synergistic effect of both improves product selectivity and low-temperature flow properties. This hydrocracking catalyst is suitable for processing VGO feedstock, yielding hydrocracking tail oil with a high viscosity index, low n-alkane content, and good low-temperature flow properties, serving as a high-quality lubricating oil base oil feedstock. Detailed Implementation

[0039] The following examples and comparative examples further illustrate the role and effect of the technical solution of the present invention, but the following examples do not constitute a limitation on the scope of protection of the present invention.

[0040] In this invention, unless otherwise specified, all percentages (%) in the embodiments and comparative examples refer to mass fractions.

[0041] In this invention, the SiO2 / Al2O3 molar ratio on the outer surface was determined by X-ray photoelectron spectroscopy (XPS). The elemental composition and state of the catalyst surface were determined using a Thermofisher Multilab2000 electron spectrometer, with Mg Kα as the excitation source and a cathode voltage and current of 13 kV and 20 mA, respectively. The electron binding energy was calibrated using C1s (284.6 eV).

[0042] In this invention, the bulk SiO2 / Al2O3 molar ratio was obtained by X-ray fluorescence spectroscopy (XRF) analysis using a ZSX100e X-ray fluorescence spectrometer with Kα spectral line, LiF1 crystal, Rh target material, SC scintillation detector, timing of 20 s, and vacuum atmosphere.

[0043] In this invention, the pyridine infrared determination method is as follows: Powdered ZSM-22 molecular sieve is compressed into tablets, vacuumed, and then degassed at 450°C for 2 hours. After the temperature drops to room temperature, pyridine molecules are used as probe molecules to measure the infrared spectrum of chemical desorption, and the adsorption amount is calculated.

[0044] In this invention, the total infrared acidity of di-tert-butylpyridine refers to the proton acid that a 2,6-di-tert-butylpyridine molecule with a kinetic diameter of 10.5 Å can contact. The infrared determination method for 2,6-di-tert-butylpyridine is as follows: Powdered ZSM-22 molecular sieve is compressed into tablets, vacuumed, and degassed at 450°C for 2 hours. After the temperature drops to room temperature, 2,6-di-tert-butylpyridine molecules are used as probe molecules to measure their infrared spectrum of chemical desorption, and the adsorption amount is calculated.

[0045] Example 1

[0046] 84.0 g of potassium hydroxide was dissolved in 4950 mL of water. While stirring, 43.3 g of aluminum sulfate octahydrate, 750.0 g of silica sol (40% by mass), and 174.0 g of 1,6-hexanediamine (DAH) were added sequentially to form a mixed gel with a molar ratio of SiO2:0.013Al2O3:0.3DAH:0.15K2O:60H2O. The initial gel was placed in a sealed reactor and crystallized at 160℃ for 3 days. The resulting mixture was washed until the pH reached 7, then filtered and dried at 120℃ to obtain ZSM-22 powder without template removal. 120 g of the ZSM-22 powder was added to 720 mL of water and mixed thoroughly. The mixture was stirred and heated to 60℃. 360 mL of 0.5 mol / L ammonium hexafluorosilicate solution was added dropwise using a peristaltic pump, maintaining the temperature at 60℃ and stirring continuously for 90 min. The filter cake was filtered while hot, and 960 mL of water was added to it. The mixture was heated to 60 °C and held for 20 min. The filter cake was then dried at 120 °C for 8 h. The dried product was then placed in a hydrothermal treatment furnace and treated at 500 °C and 0.1 MPa for 2 h. The resulting material was placed in 1200 mL of an oxalic acid-ammonium oxalate solution with a pH of 6.0 and a molar concentration of 0.3 mol / L of oxalate. The mixture was stirred and heated to 60 °C and held for 30 min. The filter cake was then filtered while hot. This process was repeated three times. The resulting filter cake was dried at 120 °C for 8 h. The modified molecular sieve was named ZSM-22-1.

[0047] Example 2

[0048] Same as in Example 1, prepare ZSM-22 powder without template removal. Take 120g of the above ZSM-22 powder, add 720mL of water and mix well. Stir and heat to 60°C. Add 360mL of 0.8mol / L tetraethyl orthosilicate solution dropwise at a constant rate using a peristaltic pump. Maintain the temperature at 60°C and continue stirring for 90min. The filter cake was filtered while hot, and 960 mL of water was added. The mixture was heated to 60 °C and held for 20 min. The filter cake was then dried at 120 °C for 8 h. The dried product was then placed in a hydrothermal treatment furnace and treated at 550 °C and 0.1 MPa for 2 h. The resulting material was placed in 1200 mL of an acetic acid-ammonium acetate solution with a pH of 5.5 and a molar concentration of acetate of 0.4 mol / L. The solution was stirred and heated to 60 °C and held for 30 min. The mixture was then filtered while hot. This process was repeated three times. The resulting filter cake was dried at 120 °C for 8 h. The modified molecular sieve was named ZSM-22-2.

[0049] Example 3

[0050] Same as in Example 1, prepare ZSM-22 powder without template removal. Take 120g of the above ZSM-22 powder, add 720mL of water and mix well. Stir and heat to 60°C. Add 360mL of 1.0mol / L tetraethyl orthosilicate solution dropwise at a constant rate using a peristaltic pump. Maintain the temperature at 60°C and continue stirring for 90min. The filter cake was filtered while hot, and 960 mL of water was added to it. The mixture was heated to 60 °C and held for 20 min. The filter cake was then dried at 120 °C for 8 h. The dried product was then placed in a hydrothermal treatment furnace and treated at 550 °C and 0.15 MPa for 2 h. The resulting material was placed in 1200 mL of an oxalic acid-ammonium oxalate solution with a pH of 5.0 and a molar concentration of 0.5 mol / L of oxalate. The mixture was stirred and heated to 60 °C and held for 30 min. The filter cake was then filtered while hot. This process was repeated three times. The resulting filter cake was dried at 120 °C for 8 h. The modified molecular sieve was named ZSM-22-3.

[0051] Example 4

[0052] Same as in Example 1, prepare ZSM-22 powder without template removal. Take 120g of the above ZSM-22 powder, add 720mL of water and mix well. Stir and heat to 60°C. Add 360mL of 1.0mol / L ammonium hexafluorosilicate solution dropwise at a uniform rate using a peristaltic pump. Maintain the temperature at 60°C and continue stirring for 90min. The filter cake was filtered while hot, and 960 mL of water was added to it. The mixture was heated to 60 °C and held for 20 min. The filter cake was then dried at 120 °C for 8 h. The dried product was then placed in a hydrothermal treatment furnace and treated at 600 °C and 0.2 MPa for 2 h. The resulting material was placed in 1200 mL of an oxalic acid-ammonium oxalate solution with a pH of 5.0 and a molar concentration of 0.6 mol / L of oxalate. The mixture was stirred and heated to 60 °C and held for 30 min. The filter cake was then filtered while hot. This process was repeated three times. The resulting filter cake was dried at 120 °C for 8 h. The modified molecular sieve was named ZSM-22-4.

[0053] Example 5

[0054] Same as in Example 1, prepare ZSM-22 powder without template removal. Take 120g of the above ZSM-22 powder, add 720mL of water and mix well. Stir and heat to 60°C. Add 360mL of 1.2mol / L tetraethyl orthosilicate solution dropwise at a constant rate using a peristaltic pump. Maintain the temperature at 60°C and continue stirring for 90min. The filter cake was filtered while hot, and 960 mL of water was added to it. The mixture was heated to 60 °C and held for 20 min. The filter cake was then dried at 120 °C for 8 h. The dried product was then placed in a hydrothermal treatment furnace and treated at 600 °C and 0.10 MPa for 2 h. The resulting material was placed in 1200 mL of an oxalic acid-ammonium oxalate solution with a pH of 5.5 and a molar concentration of 0.4 mol / L of oxalate. The mixture was stirred and heated to 60 °C and held for 30 min. The filter cake was then filtered while hot. This process was repeated three times. The resulting filter cake was dried at 120 °C for 8 h. The modified molecular sieve was named ZSM-22-5.

[0055] Example 6

[0056] Same as in Example 1, prepare ZSM-22 powder without template removal. Take 120g of the above ZSM-22 powder, add 720mL of water and mix well. Stir and heat to 60°C. Add 360mL of 1.5mol / L ammonium hexafluorosilicate solution dropwise at a uniform rate using a peristaltic pump. Maintain the temperature at 60°C and continue stirring for 90min. The filter cake was filtered while hot, and 960 mL of water was added to it. The mixture was heated to 60 °C and held for 20 min. The filter cake was then dried at 120 °C for 8 h. The dried product was then placed in a hydrothermal treatment furnace and treated at 550 °C and 0.15 MPa for 2 h. The resulting material was placed in 1200 mL of an acetic acid-ammonium acetate solution with a pH of 6.5 and a molar concentration of acetate of 0.5 mol / L. The solution was stirred and heated to 60 °C and held for 30 min. The mixture was then filtered while hot. This process was repeated three times. The resulting filter cake was dried at 120 °C for 8 h. The modified molecular sieve was named ZSM-22-6.

[0057] Comparative Example 1

[0058] Similar to Example 1, ZSM-22 powder without template removal was prepared, and then calcined at 550°C for 6 hours to obtain ZSM-22 powder with template removal. 120g of the above ZSM-22 powder was taken, added to 720mL of water and mixed evenly. The mixture was stirred and heated to 60°C. 360mL of 0.8mol / L ammonium hexafluorosilicate solution was added dropwise at a uniform rate using a peristaltic pump. The temperature was maintained at 60°C and the mixture was stirred continuously for 90min. The filter cake was filtered while hot, and 960 mL of water was added to it. The mixture was heated to 60 °C and held for 20 min. The filter cake was then dried at 120 °C for 8 h. The dried product was then placed in a hydrothermal treatment furnace and treated at 500 °C and 0.1 MPa for 2 h. The resulting material was placed in 1200 mL of an oxalic acid-ammonium oxalate solution with a pH of 6.0 and a molar concentration of 0.4 mol / L of oxalate. The mixture was stirred and heated to 60 °C and held for 30 min. The filter cake was then filtered while hot. This process was repeated three times. The resulting filter cake was dried at 120 °C for 8 h. The modified molecular sieve was named ZSM-22-D1.

[0059] Comparative Example 2

[0060] Similar to Example 1, ZSM-22 powder without template removal was prepared. 120g of the above ZSM-22 powder was placed in a hydrothermal treatment furnace and treated at 600℃ and 0.15MPa pressure for 2h. The resulting material was placed in 1200mL of oxalic acid-ammonium oxalate solution with a pH of 5.0, wherein the molar concentration of oxalate was 0.3mol / L. The mixture was stirred and heated to 60℃, held for 30min, and then filtered while hot. This process was repeated 3 times. The resulting filter cake was dried at 120℃ for 8h, and the modified molecular sieve was named ZSM-22-D2.

[0061] Table 1. Characterization results of the modified molecular sieves obtained in the examples and comparative examples.

[0062]

[0063] Example 7

[0064] 30.9g of modified molecular sieve ZSM-22-3 (97wt% dry basis), 77.8g of Y molecular sieve (relative crystallinity 130%, SiO2 / Al2O3 molar ratio 62, cell parameter 2.440nm, total pore volume 0.71mL / g, mesoporous pore volume accounting for 83% of the total pore volume, 90wt% dry basis), and 142.9g of macroporous alumina (pore volume 1.0ml / g, specific surface area 400m²) were mixed. 2 The mixture (70wt% dry basis) was placed in a roller mill and mixed. A thin binder (small pore alumina concentration 2.2 g / 100mL) was added and rolled into a paste. The paste was extruded into strips and dried at 120℃ for 6 hours. Then, it was calcined at 550℃ for 4 hours to obtain a support. The support was impregnated with a tungsten and nickel impregnation solution at room temperature for 2 hours, dried at 120℃ for 6 hours, and calcined at 500℃ for 4 hours to obtain catalyst CAT-1. The properties of the catalyst are shown in Table 2.

[0065] Example 8

[0066] 41.2g of modified molecular sieve ZSM-22-3 (97wt% dry basis), 66.7g of Y molecular sieve (same as in Example 7), and 142.9g of macroporous alumina (pore volume 1.0ml / g, specific surface area 400m²) were added. 2 The mixture (70wt% dry basis) was placed in a roller and mixed. A thin binder (2.2 g / 100mL small-pore alumina concentration) was added and rolled into a paste. The paste was extruded into strips and dried at 120℃ for 6 hours. Then, it was calcined at 550℃ for 4 hours to obtain the support. The support was impregnated with a molybdenum and nickel impregnation solution at room temperature for 2 hours, dried at 120℃ for 6 hours, and calcined at 500℃ for 4 hours to obtain the catalyst CAT-2. The properties of the catalyst are shown in Table 2.

[0067] Example 9

[0068] 51.5g of modified molecular sieve ZSM-22-4 (97wt% dry basis), 55.6g of Y molecular sieve (same as in Example 7), and 142.9g of macroporous alumina (pore volume 1.0ml / g, specific surface area 400m²) were added. 2 The mixture (70wt% dry basis) was placed in a roller mill and mixed. A thin binder (2.2 g / 100mL small-pore alumina concentration) was added and rolled into a paste. The paste was extruded into strips and dried at 120℃ for 6 hours. Then, it was calcined at 550℃ for 4 hours to obtain a support. The support was impregnated with a tungsten and nickel impregnation solution at room temperature for 2 hours, dried at 120℃ for 6 hours, and calcined at 500℃ for 4 hours to obtain catalyst CAT-3. The properties of the catalyst are shown in Table 2.

[0069] Example 10

[0070] 61.9g of modified molecular sieve ZSM-22-4 (97wt% dry basis), 44.4g of Y molecular sieve (same as in Example 7), and 142.9g of macroporous alumina (pore volume 1.0ml / g, specific surface area 400m²) were added. 2 (70wt% dry basis) was mixed in a roller mill, and a thin binder (small pore alumina concentration 2.2 g / 100mL) was added. The mixture was rolled into a paste, extruded into strips, and dried at 120℃ for 6 h. Then, it was calcined at 550℃ for 4 h to obtain a support. The support was impregnated with a molybdenum and nickel impregnation solution at room temperature for 2 h, dried at 120℃ for 6 h, and calcined at 500℃ for 4 h to obtain catalyst CAT-4. The properties of the catalyst are shown in Table 2.

[0071] Comparative Example 3

[0072] 41.2g of modified molecular sieve ZSM-22-D1 (97wt% dry basis), 66.7g of Y molecular sieve (same as in Example 7), and 142.9g of macroporous alumina (pore volume 1.0ml / g, specific surface area 400m²) were added. 2 The mixture (70wt% dry basis) was placed in a roller and mixed. A thin binder (2.2 g / 100mL small-pore alumina concentration) was added and rolled into a paste. The paste was extruded into strips and dried at 120℃ for 6 hours. Then, it was calcined at 550℃ for 4 hours to obtain a support. The support was impregnated with a tungsten and nickel impregnation solution at room temperature for 2 hours, dried at 120℃ for 6 hours, and calcined at 500℃ for 4 hours to obtain catalyst CAT-D1. The properties of the catalyst are shown in Table 2.

[0073] Comparative Example 4

[0074] 61.9g of modified molecular sieve ZSM-22-D2 (97wt% dry basis), 44.4g of Y molecular sieve (same as in Example 7), and 142.9g of macroporous alumina (pore volume 1.0ml / g, specific surface area 400m²) were added. 2 The mixture (70wt% dry basis) was placed in a roller mill and mixed. A thin binder (small-pore alumina concentration 2.2 g / 100mL) was added and rolled into a paste. The paste was extruded into strips and dried at 120℃ for 6 hours. Then, it was calcined at 550℃ for 4 hours to obtain the support. The support was impregnated with a molybdenum and nickel impregnation solution at room temperature for 2 hours, dried at 120℃ for 6 hours, and calcined at 500℃ for 4 hours to obtain the catalyst CAT-D2. The properties of the catalyst are shown in Table 2.

[0075] Table 2 Catalyst Composition and Physicochemical Properties

[0076]

[0077] Example 11

[0078] This embodiment describes the evaluation method and results obtained using the method of the present invention. Catalysts CAT-1, CAT-2, CAT-3, CAT-4, CAT-D1, and CAT-D2 were evaluated in a fixed-bed hydrogenation test apparatus under the same process conditions: a hydrogen-to-oil volume ratio of 1200:1, a reaction pressure of 14.7 MPa, and a volume hourly space velocity (VHSV) of 1.0 h⁻¹ during purification of the reaction solution. -1 The volume hourly space velocity (VHSV) of the cracking reaction liquid is 1.5 h⁻¹. -1 The conversion rate was 70%, using a single-stage series-through process. The refining catalyst was the commercially available catalyst FF-36. The feedstock used for evaluation was vacuum distillate, and its properties are shown in Table 3. The evaluation results are listed in Table 4.

[0079] The evaluation results show that the hydrocracking tail oil prepared by the method of this invention has a lower n-alkane content, a higher viscosity index, and better low-temperature flow properties, making it a very high-quality lubricating oil base oil raw material.

[0080] Table 3 Properties of Feed Oil

[0081]

[0082] Table 4. Comparison and evaluation results of catalyst performance between the examples and comparative examples

[0083]

Claims

1. A hydrocracking catalyst, said catalyst comprising a hydrogenation active metal component and a support, characterized in that: The support includes modified ZSM-22 molecular sieve and Y molecular sieve; the properties of the Y molecular sieve are as follows: relative crystallinity of 110%~150%, SiO2 / Al2O3 molar ratio of 10~100, cell parameter of 2.425~2.445nm, total pore volume of 0.55~1.0mL / g, and mesoporous pore volume accounting for more than 70% of the total pore volume; The modified ZSM-22 molecular sieve has an outer surface SiO2 / Al2O3 molar ratio of 500~1000 and a bulk SiO2 / Al2O3 molar ratio of 50~150; the total pyridine infrared acidity is 0.1~0.5 mmol / g and the total di-tert-butylpyridine infrared acidity is 0.001~0.03 mmol / g.

2. The catalyst of claim 1, wherein: The properties of the Y molecular sieve are as follows: the SiO2 / Al2O3 molar ratio is 15~70, the total pore volume is 0.6~1.0mL / g, and the mesoporous pore volume accounts for 80%~90% of the total pore volume.

3. The catalyst of claim 1, wherein: The modified ZSM-22 molecular sieve has an outer surface SiO2 / Al2O3 molar ratio of 600~900 and a bulk SiO2 / Al2O3 molar ratio of 60~120; the total pyridine infrared acidity is 0.15~0.25 mmol / g; and the total di-tert-butylpyridine infrared acidity is 0.01~0.025 mmol / g.

4. The catalyst of claim 1, wherein: The specific surface area of the hydrocracking catalyst is 250 to 450 m 2 / g, and the pore volume is 0.30 to 0.60 mL / g.

5. The catalyst of claim 1, wherein: Based on the weight of the hydrocracking catalyst, the content of the active metal component for hydrocracking, calculated as oxide, is 14%~38%, and the content of the support is 60%~85%; based on the weight of the support, the content of modified ZSM-22 molecular sieve is 10%~50%, and the content of Y molecular sieve is 10%~40%.

6. The catalyst of claim 1, wherein: The carrier contains macroporous alumina, with a content of 10% to 80% based on the weight of the carrier. The properties of the macroporous alumina are as follows: pore volume of 0.7 to 1.0 mL / g and specific surface area of ​​200 to 500 m². 2 / g.

7. The catalyst of claim 1, wherein: The hydrocracking catalyst includes a binder, and the binder content is 0.1% to 2% based on the weight of the catalyst.

8. The catalyst according to claim 1, characterized in that: In the hydrocracking catalyst, the active metal for hydrocracking is a metal of Group VIB and / or Group VIII, wherein the content of Group VIB metal as oxide is 10.0% to 30.0%, and the content of Group VIII metal as oxide is 4.0% to 8.0%.

9. The catalyst of claim 1, wherein: Group VIB metals are molybdenum and / or tungsten, and Group VIII metals are cobalt and / or nickel.

10. A process for the preparation of a hydrocracking catalyst according to any one of claims 1 to 9, characterized in that: This includes the preparation of the support and the loading of hydrogenated active metal components; the preparation process of the support is as follows: modified ZSM-22 molecular sieve, Y molecular sieve and macroporous alumina are mixed, shaped, dried and calcined to form the support.

11. The method of claim 10, wherein: The preparation method of modified ZSM-22 molecular sieve includes: (1) Preparation of ZSM-22 molecular sieve without removal of template agent; (2) Mix the ZSM-22 molecular sieve obtained in step (1) with a dealumination and silicon replenishment reagent to perform dealumination and silicon replenishment; (3) Treat the material obtained in step (2) with steam; (4) The material obtained in step (3) is treated with a buffer solution to obtain modified ZSM-22 molecular sieve.

12. The method of claim 11, wherein: In step (1), the ZSM-22 molecular sieve without template agent removal is prepared by hydrothermal synthesis.

13. The method of claim 11, wherein: In step (2), the dealuminizing and silicon replenishing reagent is at least one of ammonium hexafluorosilicate solution and tetraethyl orthosilicate solution.

14. The method of claim 11, wherein: In step (2), the molar concentration of the dealumination and silicon replenishment reagent is 0.5~1.5 mol / L; wherein the mass ratio of the ZSM-22 molecular sieve obtained in step (1) to the dealumination and silicon replenishment reagent is 1:2~1:

8.

15. The method of claim 11, wherein: In step (3), the conditions for the steam treatment are as follows: The temperature is 400~700℃, the pressure is 0.01~0.3MPa, and the time is 0.5~6h.

16. The method of claim 15, wherein: In step (3), the conditions for the steam treatment are as follows: The temperature is 500~600℃, the pressure is 0.1~0.2MPa, and the time is 1~4h.

17. The method of claim 11, wherein: In step (4), the buffer solution is one or more of oxalic acid-ammonium oxalate solution and acetic acid-ammonium acetate solution; the pH value of the buffer solution is 4.5~6.5; the molar concentration of organic acid ions in the buffer solution is 0.1~1.0 mol / L; the liquid-solid volume ratio of the buffer solution to the material obtained in step (3) is 3:1~10:1 mL / g.

18. The method of claim 17, wherein: In step (4), the pH value of the buffer solution is 5.0~6.

0.

19. The method of claim 10, wherein: In the preparation process of the carrier, the drying and calcination conditions are as follows: drying at 100℃~150℃ for 1~12h, and then calcining at 450℃~550℃ for 3.0~6.0h.

20. The method of claim 10, wherein: Hydrocracking catalysts were obtained by impregnation of active metal components for hydrogenation, followed by drying and calcination.

21. A hydrocracking process characterized by: The raw oil is reacted in the presence of any one of the hydrocracking catalysts of claims 1 to 9; the hydrocracking reaction conditions are as follows: the reaction pressure is 12.0-18.0 MPa, the temperature is 350-435℃, the hydrogen / oil volume ratio is 1000:1-2000:1, the liquid hourly space velocity is 0.5-5.0 h -1 .

22. The method according to claim 21, characterized in that: The feedstock oil is one or more of vacuum distillate oil, coking wax oil, solvent-refined deasphalted oil, and Fischer-Tropsch synthetic oil.

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