CN117696112A

CN117696112A - Hydrocracking catalyst and preparation method and application thereof

Info

Publication number: CN117696112A
Application number: CN202211016680.7A
Authority: CN
Inventors: 郭俊辉; 刘昶; 彭绍忠; 郝文月; 王凤来; 曹均丰
Original assignee: Sinopec Dalian Petrochemical Research Institute Co ltd; China Petroleum and Chemical Corp
Current assignee: Sinopec Dalian Petrochemical Research Institute Co ltd; China Petroleum and Chemical Corp
Priority date: 2022-08-24
Filing date: 2022-08-24
Publication date: 2024-03-15

Abstract

The invention discloses a hydrocracking catalyst, a preparation method and application thereof. The catalyst comprises a hydrogenation active metal component and a carrier, wherein the carrier comprises a modified ZSM-22 molecular sieve and a Y molecular sieve; the Y molecular sieve has the following properties: the relative crystallinity is 110% -150%, siO ₂ /Al ₂ O ₃ The molar ratio is 10-100, preferably 15-70, the unit cell parameter is 2.425-2.445nm, the total pore volume is 0.55-1.0 mL/g, preferably 0.6-1.0 mL/g, and the mesoporous volume occupies the total pore volume70% or more, preferably 80% to 90%. The preparation method of the hydrocracking catalyst comprises the steps of preparing a carrier and loading a hydrogenation active metal component. The hydrocracking catalyst can be used for producing a lubricating oil base oil raw material, and the obtained lubricating oil base oil raw material has the advantages of high viscosity index, low normal alkane content, good low-temperature flow property and the like.

Description

Hydrocracking catalyst and preparation method and application thereof

Technical Field

The invention relates to the field of hydrocracking, in particular to a hydrocracking catalyst and a preparation method and application thereof.

Background

The hydrocracking technology has become one of the important processing means for producing high quality chemical raw materials and clean fuel oil from poor petroleum raw materials due to the characteristics of strong raw material adaptability, flexible operation scheme, green and environment-friendly production process, high selectivity of target products, good quality and the like. In the hydrocracking reaction process, polycyclic aromatic hydrocarbon contained in the raw oil undergoes reactions such as hydrogenation saturation, ring opening conversion and the like, and the generated alkane is enriched in a tail oil product and can be used as a high-quality raw material for producing lubricating oil base oil.

The hydrocracking catalyst is a bifunctional catalyst consisting of an active metal as a hydrogenation component and a molecular sieve having acidity or amorphous silica alumina as a cracking component.

The Y-type molecular sieve is the most commonly used cracking component in the hydrocracking catalyst, has a strong ring opening conversion function on polycyclic cyclic hydrocarbon, but has weak isomerism performance, and the content of linear alkane in tail oil obtained by hydrocracking is high, so that the low-temperature flow performance of the tail oil is influenced. Therefore, molecular sieves with proper cracking performance and strong isomerism performance are used as acid cracking components together, so that the isomerism performance of the catalyst can be enhanced while the ring-opening conversion capability of the catalyst is ensured, the normal alkane content of hydrocracking tail oil is effectively reduced, and the lubricating oil base oil raw material with high viscosity index and good low-temperature fluidity is obtained.

The viscosity index of a lubricant base oil is closely related to the structure and composition of the hydrocarbons contained therein, and cyclic hydrocarbons having long side chains and isoparaffins having short side chains are desirable components of the lubricant base oil. N-alkanes, although having a very high viscosity index, have a relatively high pour point, which affects the low temperature flow properties of the lubricant and requires conversion to isoparaffins.

CN102145307a discloses a process for producing a lubricating base oil of high viscosity index, which employs a silicon-aluminum composite as the cracking component of a cracking catalyst, which exhibits excellent hydrogenation activity and middle distillate selectivity. However, the acidity of the silicon-aluminum composite material is weak, the catalyst activity is low, and the viscosity index of the lubricating oil base oil obtained by hydrocracking can only reach about 86.

US7300900B2 discloses a method for producing high-viscosity index hydrocracking tail oil, wherein a hydrocracking catalyst adopted by the method adopts one or more of ZBM-30, ZSM-48, EU-1 and other molecular sieves and Y molecular sieves as a cracking component, and the viscosity index of the obtained hydrocracking tail oil is 5 units higher than that of the hydrocracking tail oil which only uses Y molecular sieves as a cracking component under the same technological conditions.

Both CN107344108A and CN106669801A adopt Y and ZSM-48 composite molecular sieves as acidic components of a cracking catalyst, and the prepared catalyst has good ring opening conversion activity and isomerization performance through modification treatment of the molecular sieves, and can produce a hydrocracking tail oil product with low linear alkane content and high viscosity index as a lubricating oil base oil raw material.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a hydrocracking catalyst, and a preparation method and application thereof. The hydrocracking catalyst can be used for producing a lubricating oil base oil raw material, and the obtained lubricating oil base oil raw material has the advantages of high viscosity index, low normal alkane content, good low-temperature flow property and the like.

A hydrocracking catalyst, which comprises a hydrogenation active metal component and a carrier, wherein the carrier comprises a modified ZSM-22 molecular sieve and a Y molecular sieve; the Y molecular sieve has the following properties: the relative crystallinity is 110% -150%, siO ₂ /Al ₂ O ₃ The molar ratio is 10-100, preferably 15-70, the unit cell parameter is 2.425-2.445nm, the total pore volume is 0.55-1.0 mL/g, preferably 0.6-1.0 mL/g, and the mesoporous volume accounts for more than 70% of the total pore volume, preferably 80-90%.

The invention promotesIn the chemical agent, the SiO on the outer surface of the modified ZSM-22 molecular sieve ₂ /Al ₂ O ₃ The molar ratio is 500-1000, and the bulk phase SiO ₂ /Al ₂ O ₃ The molar ratio is 50-150; the total infrared acid amount of pyridine is 0.1-0.5 mmol/g, and the total infrared acid amount of di-tert-butylpyridine is 0.001-0.03 mmol/g; preferably, the modified ZSM-22 molecular sieve has an outer surface SiO ₂ /Al ₂ O ₃ The molar ratio is 600-900, and the bulk phase SiO ₂ /Al ₂ O ₃ The molar ratio is 60-120; the total infrared acid content of pyridine is 0.15-0.25 mmol/g; the infrared total acid amount of the di-tert-butylpyridine is 0.01-0.025 mmol/g.

In the catalyst, the specific surface area of the hydrocracking catalyst is 250-450 m ² The pore volume per gram is 0.30-0.60 mL/g.

In the catalyst, the weight of the hydrocracking catalyst is taken as a reference, the content of hydrogenation active metal components in terms of oxide is 14% -38%, and the content of carriers is 60% -85%; based on the weight of the carrier, the content of the modified ZSM-22 molecular sieve is 10% -50%, and the content of the Y molecular sieve is 10% -40%.

In the catalyst, the carrier further contains macroporous alumina, and the content of the macroporous alumina is 10% -80% based on the weight of the carrier. The macroporous alumina has the following properties: pore volume is 0.7-1.0 mL/g, specific surface area is 200-500 m ² /g。

In the catalyst, the hydrocracking catalyst further comprises a binder, such as small-pore alumina, and the content of the binder is 0.1% -2% based on the weight of the catalyst.

In the catalyst of the invention, in the hydrocracking catalyst, the hydrogenation active metal is a metal of a VIB group and/or a metal of a VIII group, wherein the metal of the VIB group is preferably molybdenum and/or tungsten, and the metal of the VIII group is preferably cobalt and/or nickel. In the catalyst, the content of the VIB group metal (calculated as oxide) is 10.0-30.0% and the content of the VIII group metal (calculated as oxide) is 4.0-8.0% based on the weight of the catalyst.

The preparation method of the hydrocracking catalyst comprises the steps of preparing a carrier and loading a hydrogenation active metal component; wherein, the preparation process of the carrier is as follows: mixing the modified ZSM-22 molecular sieve, the Y molecular sieve and the macroporous alumina, molding, drying and roasting to prepare a carrier; the preparation method of the modified ZSM-22 molecular sieve comprises the following steps:

(1) Preparing ZSM-22 molecular sieve without removing template;

(2) Mixing the ZSM-22 molecular sieve obtained in the step (1) with a dealumination silicon supplementing reagent to dealuminate silicon supplementing;

(3) Carrying out steam treatment on the material obtained in the step (2);

(4) And (3) treating the material obtained in the step (3) by adopting a buffer solution to obtain the modified ZSM-22 molecular sieve.

Further, in the step (1), the ZSM-22 molecular sieve without removing the template can be prepared by a hydrothermal synthesis method. For example: the silicon source, the aluminum source, the template agent, the alkali source and the water are added with SiO according to the following mole ratio ₂ ：（0.006~0.03）Al ₂ O ₃ : (0.2-4.0) R (template agent): (0.01-10) K ₂ O：（10~200）H ₂ And O, crystallizing the mixed material at 150-180 ℃ for 2-5 days, washing the product to a pH value of 7-8, and then filtering and drying at 80-120 ℃ to obtain the ZSM-22 molecular sieve without the template agent.

Further, in the preparation process of the ZSM-22 molecular sieve, the silicon source is selected from one or more of silica sol, white carbon black, ethyl orthosilicate and the like, the aluminum source is selected from one or more of aluminum sulfate octadecanoate, aluminum isopropoxide, pseudo-boehmite, potassium metaaluminate and the like, the template agent is selected from one or more of 1, 6-hexamethylenediamine, n-butylamine, diethylamine, imidazole biquaternary ammonium salt and the like, the alkali source is potassium hydroxide, and the water is deionized water.

Further, in the step (2), the dealumination and silicon supplementing agent is at least one of ammonium hexafluorosilicate solution, tetraethoxysilane solution and the like.

Further, in the step (2), the molar concentration of the dealumination silicon-supplementing reagent is 0.5-1.5 mol/L. Wherein the mass ratio of the ZSM-22 molecular sieve obtained in the step (1) to the dealumination silicon-supplementing reagent is 1:2-1:8.

Further, in the step (2), the specific operation process of dealumination and silicon supplementing is as follows: uniformly mixing the ZSM-22 molecular sieve obtained in the step (1) with water, heating to 60-100 ℃, continuously stirring, dripping a dealumination silicon-supplementing reagent, continuously stirring for 60-120 min after dripping, filtering while the mixture is hot, washing the obtained filter cake with water, filtering again, and drying. Wherein the liquid-solid volume ratio of water to the ZSM-22 molecular sieve obtained in the step (1) is 2:1-8:1 mL/g.

Further, in the step (3), the conditions of the steam treatment are as follows: the temperature is 400-700 ℃, preferably 500-600 ℃, the pressure is 0.01-0.3 MPa, preferably 0.1-0.2 MPa, and the time is 0.5-6 h, preferably 1-4 h.

Further, in the 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, preferably 5.0-6.0. In the buffer solution, the molar concentration of the organic acid radical is 0.1-1.0 mol/L. The liquid-solid volume ratio of the buffer solution to the material obtained in the step (3) is 3:1-10:1 mL/g.

Further, in the step (4), the specific processing procedure is as follows: and (3) mixing and stirring the material obtained in the step (3) with a buffer solution, wherein the treatment temperature is 40-80 ℃ and the treatment time is 0.5-3 h.

Further, in the step (4), solid-liquid separation (such as suction filtration) is performed; and repeating the operation for 2-4 times, and drying the finally obtained material to obtain the modified ZSM-22 molecular sieve.

In the method, in the preparation process of the carrier, conventional conditions can be adopted for drying and roasting, namely, the drying is generally carried out for 1-12 h at 100-150 ℃, and then the roasting is carried out for 3.0-6.0 h at 450-550 ℃.

In the process of the present invention, the Y molecular sieve can be prepared according to the prior art, for example, according to the process of CN 201610289588.6.

In the method of the present invention, the catalyst support is loaded with the hydrogenation-active metal component by a conventional means such as a kneading method, an impregnation method, etc. In the invention, the hydrogenation active metal component is preferably loaded by an impregnation method, and then the hydrocracking catalyst is obtained by drying and roasting. The impregnation method can be saturated impregnation, excessive impregnation or complex impregnation, namely, the catalyst carrier is impregnated with a solution containing the required active components, the impregnated carrier is dried for 1-12 h at 100-150 ℃, and then the impregnated carrier is baked for 3.0-6.0 h at 450-550 ℃ to obtain the final catalyst.

A hydrocracking method, wherein raw oil reacts in the presence of a hydrocracking catalyst; the hydrocracking reaction conditions are as follows: the reaction pressure is 12.0-18.0 MPa, the temperature is 350-435 ℃, and the hydrogen-oil volume ratio is 1000: 1-2000: 1, the liquid hourly space velocity is 0.5-5.0 h ^-1 。

In the hydrocracking method, the raw oil is one or more of vacuum distillate oil, coker wax oil, solvent refined deasphalted oil and Fischer-Tropsch synthetic oil.

Compared with the prior art, the hydrocracking catalyst and the preparation method and application thereof have the following advantages:

1. according to the preparation method of the modified ZSM-22 molecular sieve, firstly, the molecular sieve obtained by hydrothermal synthesis is not treated by a template removing agent, organic template molecules in a pore canal serve as a pore canal protective agent, and the acidic center of the outer surface of the molecular sieve is removed at fixed points by using a dealumination and silicon supplementing method, so that the excessive cracking reaction of normal alkane on the outer surface of the molecular sieve is reduced. The aluminum on the outer surface of the molecular sieve is replaced by silicon atoms which do not have acidity under the action of dealumination silicon-supplementing reagent, and the acid center in the pore canal is protected due to the existence of template agent molecules. The method of constant pressure high temperature steam treatment reduces the total acid amount of the molecular sieve and removes the template molecules in the pore canal. Finally, non-framework aluminum generated in the hydro-thermal treatment process is removed by adopting a buffer solution, so that the pore canal of the molecular sieve is more open and smooth, and the diffusion of intermediate products in the normal alkane shape-selective isomerization reaction process is easy.

2. The modified ZSM-22 molecular sieve adopted by the catalyst in the method has low total infrared acid content of the di-tert-butylpyridine, eliminates acid sites on the outer surface, has an open and smooth pore channel structure, strengthens the isomerism performance of the molecular sieve, and takes the modified ZSM-22 molecular sieve and the Y molecular sieve together as a cracking center, thereby not only fully playing the respective performance characteristics of the modified ZSM-22 molecular sieve, but also enabling the two molecular sieves to produce synergistic catalysis, namely the Y molecular sieve provides proper cracking performance of the catalyst, leading cyclic hydrocarbon to be converted into chain hydrocarbon through ring opening, and the ZSM-22 molecular sieve strengthens the isomerism performance of the catalyst, leading normal alkane to be converted into isoparaffin, and improving the low-temperature flow performance of the product when the selectivity of the product is improved. The hydrocracking catalyst is suitable for processing VGO raw materials, and can obtain the hydrocracking tail oil with high viscosity index, low normal alkane content and good low-temperature fluidity, which is used as a high-quality lubricating oil base oil raw material.

Detailed Description

The following examples and comparative examples are provided to further illustrate the operation and effects of the present invention, but the following examples do not limit the scope of the present invention.

In the present invention, the percentages related to examples and comparative examples are mass fractions unless otherwise specified.

In the invention, the outer surface SiO ₂ /Al ₂ O ₃ The molar ratio is measured by X-ray photoelectron spectroscopy (XPS), the elemental composition and state of the catalyst surface are measured by using a Multilab2000 electronic spectrometer of the American Thermofisher company, the excitation source is Mg K alpha, and the cathode voltage and current are 13kV and 20mA respectively. The electron binding energy was scaled with C1s (284.6 eV).

In the present invention, bulk SiO ₂ /Al ₂ O ₃ The molar ratio is obtained by X-ray fluorescence spectrum (XRF) analysis, a ZSX100e X-ray fluorescence spectrometer is adopted, spectral line is Kα, crystal is Li F1, target material is Rh, detector is SC scintillation, timing is 20 s, and light path atmosphere is vacuum.

In the invention, the pyridine infrared measurement method comprises the following steps: the powdery ZSM-22 molecular sieve is pressed into tablets, vacuumized and degassed for 2 hours at 450 ℃. And (3) when the temperature is reduced to room temperature, using pyridine molecules as probe molecules, measuring an infrared spectrogram of chemical desorption, and calculating the adsorption quantity.

In the present invention, the total infrared acid amount of the di-tert-butylpyridine refers to the proton acid which can be contacted by the 2, 6-di-tert-butylpyridine molecule with the kinetic diameter of 10.5A. The infrared measurement method of the 2, 6-di-tert-butylpyridine comprises the following steps: the powdery ZSM-22 molecular sieve is pressed into tablets, vacuumized and degassed for 2 hours at 450 ℃. And when the temperature is reduced to room temperature, 2, 6-di-tert-butylpyridine molecules are used as probe molecules, an infrared spectrogram of chemical desorption is measured, and the adsorption quantity is calculated.

Example 1

84.0g of potassium hydroxide is weighed and dissolved in 4950mL of water, 43.3g of aluminum sulfate octadecanoate, 750.0g of silica sol (the mass fraction is 40 percent) and 174.0g of 1, 6-hexamethylenediamine (DAH) are added in sequence during stirring to form the SiO molar ratio of the materials ₂ ：0.013Al ₂ O ₃ ：0.3DAH：0.15K ₂ O：60H ₂ And (3) mixing gel of O, loading the mixed initial gel into a closed reaction kettle, crystallizing for 3 days at 160 ℃, washing the obtained mixture product to a pH value of 7, and then filtering and drying at 120 ℃ to obtain ZSM-22 powder without template removal. 120g of the ZSM-22 powder is taken, 720mL of water is added for uniform mixing, stirring and heating are carried out to 60 ℃, 360mL of 0.5mol/L ammonium hexafluorosilicate solution is dripped at uniform speed by a peristaltic pump, the temperature is kept at 60 ℃, and stirring is continued for 90min. Adding 960mL of water into the obtained filter cake, heating to 60 ℃ and keeping for 20min, carrying out suction filtration while the filter cake is hot, drying the filter cake at 120 ℃ for 8h, then placing the dried product into a water heat treatment furnace, treating for 2h at 500 ℃ and 0.1MPa, placing the obtained material into 1200mL of oxalic acid-ammonium oxalate solution with the pH value of 6.0, wherein the molar concentration of oxalate is 0.3mol/L, stirring and heating to 60 ℃, keeping for 30min, carrying out suction filtration while the filter cake is hot, repeating the process for 3 times, and drying the obtained filter cake at 120 ℃ for 8h, thereby obtaining the modified molecular sieve named ZSM-22-1.

Example 2

As in example 1, ZSM-22 powder was prepared without removing the template. 120g of the ZSM-22 powder is taken, 720mL of water is added for uniform mixing, stirring and heating are carried out to 60 ℃, 360mL of 0.8mol/L tetraethoxysilane solution is dripped at uniform speed by a peristaltic pump, the temperature is kept at 60 ℃, and stirring is continued for 90min. Adding 960mL of water into the obtained filter cake, heating to 60 ℃ and keeping for 20min, carrying out suction filtration while the filter cake is hot, drying the filter cake at 120 ℃ for 8h, then placing the dried product into a water heat treatment furnace, treating for 2h at 550 ℃ and 0.1MPa, placing the obtained material into 1200mL of acetic acid-ammonium acetate solution with the pH value of 5.5, wherein the molar concentration of acetate is 0.4mol/L, stirring and heating to 60 ℃, keeping for 30min, carrying out suction filtration while the filter cake is hot, repeating the process for 3 times, and drying the obtained filter cake at 120 ℃ for 8h to obtain the modified molecular sieve named ZSM-22-2.

Example 3

As in example 1, ZSM-22 powder was prepared without removing the template. 120g of the ZSM-22 powder is taken, 720mL of water is added for uniform mixing, stirring and heating are carried out to 60 ℃, 360mL of 1.0mol/L tetraethoxysilane solution is dripped at uniform speed by a peristaltic pump, the temperature is kept at 60 ℃, and stirring is continued for 90min. Adding 960mL of water into the obtained filter cake, heating to 60 ℃ and keeping for 20min, carrying out suction filtration while the filter cake is hot, drying the filter cake at 120 ℃ for 8h, then placing the dried product into a water heat treatment furnace, treating the dried product for 2h under the pressure of 0.15MPa at 550 ℃, placing the obtained material into 1200mL of oxalic acid-ammonium oxalate solution with the pH value of 5.0, wherein the molar concentration of oxalate is 0.5mol/L, stirring and heating to 60 ℃, keeping for 30min, carrying out suction filtration while the filter cake is hot, repeating the process for 3 times, and drying the obtained filter cake at 120 ℃ for 8h to obtain the modified molecular sieve named ZSM-22-3.

Example 4

As in example 1, ZSM-22 powder was prepared without removing the template. 120g of the ZSM-22 powder is taken, 720mL of water is added for uniform mixing, stirring and heating are carried out to 60 ℃, 360mL of 1.0mol/L ammonium hexafluorosilicate solution is dripped at uniform speed by a peristaltic pump, the temperature is kept at 60 ℃, and stirring is continued for 90min. Adding 960mL of water into the obtained filter cake, heating to 60 ℃ and keeping for 20min, carrying out suction filtration while the filter cake is hot, drying the filter cake at 120 ℃ for 8h, then placing the dried product into a water heat treatment furnace, treating the dried product for 2h under the pressure of 600 ℃ and 0.2MPa, placing the obtained material into 1200mL of oxalic acid-ammonium oxalate solution with the pH value of 5.0, wherein the molar concentration of oxalate is 0.6mol/L, stirring and heating to 60 ℃, keeping for 30min, carrying out suction filtration while the filter cake is hot, repeating the process for 3 times, and drying the obtained filter cake at 120 ℃ for 8h, thereby obtaining the modified molecular sieve named ZSM-22-4.

Example 5

As in example 1, ZSM-22 powder was prepared without removing the template. 120g of the ZSM-22 powder is taken, 720mL of water is added for uniform mixing, stirring and heating are carried out to 60 ℃, 360mL of 1.2mol/L tetraethoxysilane solution is dripped at uniform speed by a peristaltic pump, the temperature is kept at 60 ℃, and stirring is continued for 90min. Adding 960mL of water into the obtained filter cake, heating to 60 ℃ and keeping for 20min, carrying out suction filtration while the filter cake is hot, drying the filter cake at 120 ℃ for 8h, then placing the dried product into a water heat treatment furnace, treating for 2h at 600 ℃ and 0.10MPa, placing the obtained material into 1200mL of oxalic acid-ammonium oxalate solution with the pH value of 5.5, wherein the molar concentration of oxalate is 0.4mol/L, stirring and heating to 60 ℃, keeping for 30min, carrying out suction filtration while the filter cake is hot, repeating the process for 3 times, and drying the obtained filter cake at 120 ℃ for 8h, wherein the obtained modified molecular sieve is named ZSM-22-5.

Example 6

As in example 1, ZSM-22 powder was prepared without removing the template. 120g of the ZSM-22 powder is taken, 720mL of water is added for uniform mixing, stirring and heating are carried out to 60 ℃, 360mL of 1.5mol/L ammonium hexafluorosilicate solution is dripped at uniform speed by a peristaltic pump, the temperature is kept at 60 ℃, and stirring is continued for 90min. Adding 960mL of water into the obtained filter cake, heating to 60 ℃ and keeping for 20min, carrying out suction filtration while the filter cake is hot, drying the filter cake at 120 ℃ for 8h, then placing the dried product into a water heat treatment furnace, treating the dried product for 2h under the pressure of 0.15MPa at 550 ℃, placing the obtained material into 1200mL of acetic acid-ammonium acetate solution with the pH value of 6.5, wherein the molar concentration of acetate is 0.5mol/L, stirring and heating to 60 ℃, keeping for 30min, carrying out suction filtration while the filter cake is hot, repeating the process for 3 times, and drying the obtained filter cake at 120 ℃ for 8h to obtain the modified molecular sieve named ZSM-22-6.

Comparative example 1

As in example 1, ZSM-22 powder without removing the template was prepared, followed by calcination at 550℃for 6 hours to obtain ZSM-22 powder with the template removed. 120g of the ZSM-22 powder is taken, 720mL of water is added for uniform mixing, stirring and heating are carried out to 60 ℃, 360mL of 0.8mol/L ammonium hexafluorosilicate solution is dripped at uniform speed by a peristaltic pump, the temperature is kept at 60 ℃, and stirring is continued for 90min. Adding 960mL of water into the obtained filter cake, heating to 60 ℃ and keeping for 20min, carrying out suction filtration while the filter cake is hot, drying the filter cake at 120 ℃ for 8h, then placing the dried product into a water heat treatment furnace, treating for 2h at 500 ℃ and 0.1MPa, placing the obtained material into 1200mL of oxalic acid-ammonium oxalate solution with the pH value of 6.0, wherein the molar concentration of oxalate is 0.4mol/L, stirring and heating to 60 ℃, keeping for 30min, carrying out suction filtration while the filter cake is hot, repeating the process for 3 times, and drying the obtained filter cake at 120 ℃ for 8h to obtain the modified molecular sieve named ZSM-22-D1.

Comparative example 2

As in example 1, ZSM-22 powder was prepared without removing the template. 120g of ZSM-22 powder is placed in a water heat treatment furnace, the water heat treatment furnace is treated for 2 hours under the pressure of 0.15MPa at 600 ℃, the obtained material is placed in 1200mL of oxalic acid-ammonium oxalate solution with the pH value of 5.0, wherein the molar concentration of oxalate is 0.3mol/L, the mixture is stirred and heated to 60 ℃, the temperature is kept for 30min, the hot suction filtration is carried out, the process is repeated for 3 times, and the obtained filter cake is dried for 8 hours at 120 ℃, and the obtained modified molecular sieve is named ZSM-22-D2.

Table 1 characterization results of modified molecular sieves obtained in examples and comparative examples

Example 7

30.9g of modified molecular sieve ZSM-22-3 (97% by weight on a dry basis), 77.8g of g Y molecular sieve (130% relative crystallinity, siO) ₂ /Al ₂ O ₃ The molar ratio is 62, the unit cell parameter is 2.440nm, the total pore volume is 0.71mL/g, the mesoporous pore volume accounts for 83 percent of the total pore volume, the dry basis is 90wt percent), 142.9g of macroporous alumina (pore volume is 1.0mL/g, the specific surface area is 400m ² And (3) adding 70wt% of dry basis into a rolling machine, mixing and grinding, adding a dilute adhesive (the concentration of the small-pore alumina is 2.2 g/100 mL), grinding into paste, extruding strips, drying the extruded strips at 120 ℃ for 6h, roasting at 550 ℃ for 4h to obtain a carrier, soaking the carrier in a soaking solution containing tungsten and nickel at room temperature for 2h, drying at 120 ℃ for 6h, and roasting at 500 ℃ for 4h at a programmed temperature to obtain the catalyst CAT-1, wherein the catalyst properties are shown in Table 2.

Example 8

41.2g of modified molecular sieve ZSM-22-3 (97 wt% based on dry matter), 66.7. 66.7g Y molecular sieve (same as in example 7), 142.9g of macroporous alumina (pore volume 1)0ml/g, specific surface area 400m ² And (3) adding 70wt% of dry basis into a rolling machine, mixing and grinding, adding a dilute adhesive (the concentration of the small-pore alumina is 2.2 g/100 mL), grinding into paste, extruding strips, drying the extruded strips at 120 ℃ for 6h, roasting at 550 ℃ for 4h to obtain a carrier, soaking the carrier in a molybdenum and nickel-containing impregnating solution at room temperature for 2h, drying at 120 ℃ for 6h, and roasting at 500 ℃ for 4h at a programmed temperature to obtain the catalyst CAT-2, wherein the catalyst properties are shown in Table 2.

Example 9

51.5g of modified molecular sieve ZSM-22-4 (97 wt% on a dry basis), 55.6. 55.6g Y molecular sieve (same as in example 7), 142.9g of macroporous alumina (pore volume 1.0ml/g, specific surface area 400 m) ² And (3) adding 70wt% of dry basis into a rolling machine, mixing and grinding, adding a dilute adhesive (the concentration of the small-pore alumina is 2.2 g/100 mL), grinding into paste, extruding strips, drying the extruded strips at 120 ℃ for 6h, roasting at 550 ℃ for 4h to obtain a carrier, soaking the carrier in a soaking solution containing tungsten and nickel at room temperature for 2h, drying at 120 ℃ for 6h, and roasting at 500 ℃ for 4h at a programmed temperature to obtain the catalyst CAT-3, wherein the catalyst properties are shown in Table 2.

Example 10

61.9g of modified molecular sieve ZSM-22-4 (97 wt% based on dry matter), 44.4. 44.4g Y molecular sieve (same as in example 7), 142.9g of macroporous alumina (pore volume 1.0ml/g, specific surface area 400 m) ² And (3) adding 70wt% of dry basis into a rolling machine, mixing and grinding, adding a dilute adhesive (the concentration of the small-pore alumina is 2.2 g/100 mL), grinding into paste, extruding strips, drying the extruded strips at 120 ℃ for 6h, roasting at 550 ℃ for 4h to obtain a carrier, soaking the carrier in a molybdenum and nickel-containing impregnating solution at room temperature for 2h, drying at 120 ℃ for 6h, and roasting at 500 ℃ for 4h at a programmed temperature to obtain the catalyst CAT-4, wherein the catalyst properties are shown in Table 2.

Comparative example 3

41.2g of modified molecular sieve ZSM-22-D1 (97 wt% based on dry basis), 66.7. 66.7g Y molecular sieve (same as in example 7), 142.9g of macroporous alumina (pore volume 1.0ml/g, specific surface area 400 m) ² Mixing/g, dry 70 wt%) in a rolling machine, adding dilute binder (small-pore alumina concentration 2.2 g/100 mL), rolling to paste, extruding, drying at 120deg.C for 6 hr, calcining at 550deg.C for 4 hr to obtain carrier, soaking with tungsten and nickel-containing soaking solution at room temperature for 2 hr, drying at 120deg.C for 6 hr, and calcining at 500deg.C for 4 hr to obtain the final productCatalyst CAT-D1 and catalyst properties are shown in Table 2.

Comparative example 4

61.9g of modified molecular sieve ZSM-22-D2 (97% by weight on a dry basis), 44.4. 44.4g Y molecular sieve (same as in example 7), 142.9g of macroporous alumina (pore volume 1.0ml/g, specific surface area 400 m) ² And (3) adding 70wt% of dry basis into a rolling machine, mixing and grinding, adding a dilute adhesive (the concentration of the small-pore alumina is 2.2 g/100 mL), grinding into paste, extruding strips, drying the extruded strips at 120 ℃ for 6h, roasting at 550 ℃ for 4h to obtain a carrier, soaking the carrier in a molybdenum and nickel-containing impregnating solution at room temperature for 2h, drying at 120 ℃ for 6h, and roasting at 500 ℃ for 4h at a programmed temperature to obtain the catalyst CAT-D2, wherein the catalyst properties are shown in Table 2.

TABLE 2 catalyst composition and physicochemical Properties

Example 11

This example describes the evaluation method and results from the method of the present invention. The 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: the volume ratio of hydrogen to oil is 1200:1, the reaction pressure is 14.7MPa, and the volume space velocity of the refined reaction liquid is 1.0h ^-1 The space velocity of the time volume of the cracking reaction liquid is 1.5h ^-1 The conversion was 70% using a one-pass series process wherein the refined catalyst was commercial catalyst FF-36. The raw oil used for the evaluation was a vacuum distillate, the properties of which are shown in Table 3, and the evaluation results obtained are shown in Table 4.

As can be seen from the evaluation results, the hydrocracking tail oil prepared by the method has lower normal paraffin content, higher viscosity index and better low-temperature flow property, and is a very high-quality lubricating oil base oil raw material.

TABLE 3 Properties of raw oil

Table 4 comparative evaluation results of catalyst performances of examples and comparative examples

Claims

1. A hydrocracking catalyst comprising a hydrogenation-active metal component and a support, characterized in that: the carrier comprises a modified ZSM-22 molecular sieve and a Y molecular sieve; the Y molecular sieve has the following properties: the relative crystallinity is 110% -150%, siO ₂ /Al ₂ O ₃ The molar ratio is 10-100, preferably 15-70, the unit cell parameter is 2.425-2.445nm, the total pore volume is 0.55-1.0 mL/g, preferably 0.6-1.0 mL/g, and the mesoporous volume accounts for more than 70% of the total pore volume, preferably 80-90%.

2. The catalyst of claim 1, wherein: the SiO on the outer surface of the modified ZSM-22 molecular sieve ₂ /Al ₂ O ₃ The molar ratio is 500-1000, and the bulk phase SiO ₂ /Al ₂ O ₃ The molar ratio is 50-150; the total infrared acid amount of pyridine is 0.1-0.5 mmol/g, and the total infrared acid amount of di-tert-butylpyridine is 0.001-0.03 mmol/g.

3. The catalyst of claim 2, wherein: the SiO on the outer surface of the modified ZSM-22 molecular sieve ₂ /Al ₂ O ₃ The molar ratio is 600-900, and the bulk phase SiO ₂ /Al ₂ O ₃ The molar ratio is 60-120; the total infrared acid content of pyridine is 0.15-0.25 mmol/g; the infrared total acid amount of the di-tert-butylpyridine is 0.01-0.025 mmol/g.

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

5. The catalyst of claim 1, wherein: the weight of the hydrocracking catalyst is taken as a reference, the content of the hydrogenation active metal component in terms of oxide is 14% -38%, and the content of the carrier is 60% -85%; based on the weight of the carrier, the content of the modified ZSM-22 molecular sieve is 10% -50%, and the content of the Y molecular sieve is 10% -40%.

6. The catalyst of claim 1, wherein: the carrier contains macroporous alumina, the content of the macroporous alumina is 10% -80% based on the weight of the carrier, and the macroporous alumina has the following properties: pore volume is 0.7-1.0 mL/g, specific surface area is 200-500 m ² /g。

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

8. The catalyst of claim 1, wherein: in the hydrocracking catalyst, the hydrogenation active metal is metal of VIB group and/or VIII group, the content of the metal of VIB group is 10.0% -30.0% in terms of oxide, and the content of the metal of VIII group is 4.0% -8.0% in terms of oxide.

9. The catalyst of claim 1, wherein: the group VIB metal is molybdenum and/or tungsten, and the group VIII metal is cobalt and/or nickel.

10. A process for the preparation of a hydrocracking catalyst as claimed in any one of claims 1 to 9, characterized in that: comprises the preparation of a carrier and the loading of a hydrogenation active metal component; wherein, the preparation process of the carrier is as follows: mixing the modified ZSM-22 molecular sieve, the Y molecular sieve and the macroporous alumina, molding, drying and roasting to prepare the carrier.

11. The method according to claim 10, wherein: the preparation method of the modified ZSM-22 molecular sieve comprises the following steps:

(1) Preparing ZSM-22 molecular sieve without removing template;

(3) Carrying out steam treatment on the material obtained in the step (2);

12. The method according to claim 10, wherein: in the step (1), the ZSM-22 molecular sieve without the template agent is prepared by adopting a hydrothermal synthesis method.

13. The method according to claim 10, wherein: in the step (2), the dealumination and silicon supplementing reagent is at least one of ammonium hexafluorosilicate solution and tetraethoxysilane solution.

14. The method according to claim 10, wherein: in the step (2), the molar concentration of the dealumination and silicon supplementing reagent is 0.5-1.5 mol/L; wherein the mass ratio of the ZSM-22 molecular sieve obtained in the step (1) to the dealumination silicon-supplementing reagent is 1:2-1:8.

15. The method according to claim 10, wherein: in the step (3), the conditions of the steam treatment are as follows: the temperature is 400-700 ℃, preferably 500-600 ℃, the pressure is 0.01-0.3 MPa, preferably 0.1-0.2 MPa, and the time is 0.5-6 h, preferably 1-4 h.

16. The method according to claim 10, wherein: in the 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, preferably 5.0-6.0; in the buffer solution, the molar concentration of the organic acid radical is 0.1-1.0 mol/L; the liquid-solid volume ratio of the buffer solution to the material obtained in the step (3) is 3:1-10:1 mL/g.

17. The method according to claim 10, wherein: in the preparation process of the carrier, conventional conditions can be adopted for drying and roasting, namely, the drying and roasting are generally carried out at 100-150 ℃ for 1-12 h, and then the roasting is carried out at 450-550 ℃ for 3.0-6.0 h.

18. The method according to claim 10, wherein: the hydrogenation active metal component is loaded by adopting an impregnation method, and then the hydrocracking catalyst is obtained by drying and roasting.

19. A hydrocracking process characterized by: reacting a feedstock in the presence of a hydrocracking catalyst according to any one 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 ℃, and the hydrogen-oil volume ratio is 1000: 1-2000: 1, the liquid hourly space velocity is 0.5-5.0 h ^-1 。

20. The method according to claim 19, wherein: the raw oil is one or more of vacuum distillate oil, coker gas oil, solvent refined deasphalted oil and Fischer-Tropsch synthetic oil.