Hydroisomerization catalyst, method for producing the same, and hydroisomerization treatment method for hydrocarbon oil

Abstract

The application relates to the field of catalysts, and discloses a hydroisomerization catalyst, a preparation method thereof and a hydroisomerization treatment method for hydrocarbon oil, which comprises the following steps: (1) performing molding on a ZSM-48 molecular sieve precursor to obtain a carrier precursor; wherein the water content of the ZSM-48 molecular sieve precursor is not less than 15 wt% based on the mass of the ZSM-48 molecular sieve precursor; (2) performing ammonium exchange on the carrier precursor to obtain a catalyst carrier; (3) introducing an active metal component onto the catalyst carrier to obtain a hydroisomerization catalyst; wherein the active metal component is Pt and / or Pd. The hydroisomerization catalyst obtained by the above preparation method has a lower product condensation point and a higher yield in the hydroisomerization reaction of hydrocarbon oil than the product obtained by the prior art, and has a remarkable effect.

Description

Technical Field

[0001] This invention relates to the field of catalysts, specifically to a hydroisomerization catalyst and its preparation method, and a method for hydroisomerization treatment of hydrocarbon oils. Background Technology

[0002] Hydroisomerization of hydrocarbon oils involves isomerizing alkanes in the presence of a hydroisomerization catalyst. This method improves the low-temperature fluidity of the oil while maintaining a suitable viscosity. The performance of the isomerization pour point depressant catalyst determines the product yield, low-temperature fluidity, viscosity index loss, cost, and long-term operational stability. To meet the industrial demand for reducing the production cost of high-grade lubricating oil base oils, it is necessary to increase the yield of lubricating oil base oil products, reduce viscosity index loss, and further lower the pour point. Existing catalysts are insufficient to meet these requirements, necessitating the search for isomerization pour point depressant catalysts with superior performance.

[0003] Hydroisomerization catalyst support materials typically contain different types of molecular sieves. Molecular sieve materials possess high acidity and high specific surface area, making them excellent acidic catalysts. Simultaneously, molecular sieve materials exhibit strong chemical and hydrothermal stability, making them difficult to corrode or dissolve by reactants. Compared to commonly used homogeneous catalysts, molecular sieve catalysts can be directly reused without separation, and do not pollute the environment or the product. Numerous attempts have been made in existing technologies to improve catalyst performance through molecular sieve modification.

[0004] ZSM-48 molecular sieves are a novel high-silica molecular sieve developed in the 1980s. They possess a two-dimensional ten-membered ring channel structure, belong to the orthorhombic crystal system, and are connected by five-membered ring phases. The pore diameter is approximately 0.6 nm. Their key features include a high silicon-to-aluminum molar ratio and tubular, straight channels, allowing for reactions involving organic molecules with kinetic radii smaller than benzene. Theoretically, ZSM-48 molecular sieves exhibit a relatively small channel "self-blocking effect," and their channel size is suitable for shape-selective isomerism of alkanes. Current technologies primarily focus on controlling the crystal phase of ZSM-48 molecular sieves and selecting template agents for synthesis, with limited reports on controlling the morphology and size of ZSM-48 molecular sieves. Furthermore, the preparation process for catalysts containing ZSM-48 molecular sieves in existing technologies is lengthy, requiring multiple drying and calcination processes, and production efficiency needs further improvement.

[0005] In existing technologies, catalyst preparation typically involves crystallization followed by ammonium exchange, and then extrusion molding. For example, CN110756220A discloses a method for preparing a ZSM-35 / ZSM-5 eutectic molecular sieve catalyst, employing crystallization, filtration, washing, ammonium exchange, drying, and calcination to obtain the molecular sieve product, which is then extruded with a binder, acid, and additives. This preparation process is complex, post-processing is difficult, requiring multiple drying and calcination processes, and the ammonium exchange filtration efficiency is low, making it unsuitable for industrial production. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems of long preparation processes for hydroisomerization catalysts in existing technologies, and low product yields and high pour points when the catalysts are used in hydrocarbon oil hydroisomerization reactions. This invention provides a hydroisomerization catalyst, its preparation method, and a hydrocarbon oil hydroisomerization treatment method. When the catalyst prepared by this method is applied to hydrocarbon oil hydroisomerization reactions, the product yield is higher and the pour point is lower.

[0007] To achieve the above objectives, the first aspect of the present invention provides a method for preparing a hydroisomerization catalyst, comprising the following steps:

[0008] (1) The ZSM-48 molecular sieve precursor was shaped to obtain the carrier precursor;

[0009] Based on the mass of the ZSM-48 molecular sieve precursor, the water content of the ZSM-48 molecular sieve precursor is not less than 15 wt%.

[0010] (2) The carrier precursor is subjected to ammonium exchange to obtain a catalyst support;

[0011] (3) Introduce an active metal component onto the catalyst support to obtain a hydroisomerization catalyst;

[0012] The active metal component is Pt and / or Pd.

[0013] A second aspect of the present invention provides a hydroisomerization catalyst prepared by the above preparation method.

[0014] A third aspect of the present invention provides a method for hydroisomerization of hydrocarbon oil, the method comprising: contacting a feedstock oil with a hydroisomerization catalyst under hydroisomerization conditions, wherein the feedstock oil is selected from at least one of cracking tail oil, bio-jet fuel production feedstock, C5C6 isomerization feedstock, and Fischer-Tropsch synthesis wax, and the hydroisomerization catalyst is the hydroisomerization catalyst provided in the second aspect above.

[0015] The preparation method of the hydroisomerization catalyst provided by the present invention has a short preparation process and simple operation. It can avoid the steps of drying and calcining molecular sieves. By first forming and then exchanging ammonium, it is beneficial to reduce the difficulty of post-processing. The obtained hydroisomerization catalyst has a lower pour point and higher yield in the hydroisomerization reaction of hydrocarbon oils than the products obtained by the prior art, which has a significant effect. Attached Figure Description

[0016] Figure 1 The X-ray diffraction pattern of seed crystal A1 obtained in Preparation Example 1-1 after calcination;

[0017] Figure 2 The X-ray diffraction pattern of seed crystal A3 obtained in Preparation Examples 1-3 after calcination;

[0018] Figure 3 This is a SEM image of the ZSM-48 molecular sieve obtained in Preparation Example 2-1. Detailed Implementation

[0019] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0020] The first aspect of this invention provides a method for preparing a hydroisomerization catalyst, comprising the following steps:

[0021] (1) The ZSM-48 molecular sieve precursor was shaped to obtain the carrier precursor;

[0022] Wherein, based on the mass of the ZSM-48 molecular sieve precursor, the water content of the ZSM-48 molecular sieve precursor is not less than 15%;

[0023] (2) The carrier precursor is subjected to ammonium exchange to obtain a catalyst support;

[0024] (3) Introduce an active metal component onto the catalyst support to obtain a hydroisomerization catalyst;

[0025] The active metal component is Pt and / or Pd.

[0026] In this invention, the ZSM-48 molecular sieve precursor refers to uncalcined ZSM-48 molecular sieve, such as filter cake or raw molecular sieve powder containing ZSM-48 molecular sieve, as long as it meets the above-mentioned moisture content requirements. In conventional catalyst preparation processes, the dried and calcined raw molecular sieve powder generally requires ammonium exchange before drying, shaping, and calcining. This process is lengthy, and directly processing the raw molecular sieve powder after ammonium exchange is difficult. The inventors of this invention discovered that the high moisture content in the ZSM-48 molecular sieve precursor facilitates shaping. Furthermore, by performing ammonium exchange after shaping, the additional drying and calcining process can be omitted, significantly reducing the preparation process and improving catalyst production efficiency. Simultaneously, the resulting catalyst exhibits a lower pour point and higher yield in hydrocarbon hydroisomerization reactions compared to products obtained using existing technologies.

[0027] In this invention, the method for testing water content is as follows: take a mass of M... 烘干前 The filter cake sample was placed in an oven and dried at 105-110℃ for about 6-8 hours until the sample weight no longer changed. The dried sample was then weighed and recorded as M. 烘干后 The moisture content of the filter cake can be calculated.

[0028] Filter cake moisture content (wt%) = (M 烘干前 -M 烘干后 ) / M 烘干前 3100%.

[0029] In this invention, preferably, the water content of the ZSM-48 molecular sieve precursor is 15-40 wt%, based on the mass of the ZSM-48 molecular sieve precursor. In the above preferred case, it helps to cooperate with the additives and binders during extrusion molding, improves the strength of the carrier precursor, and reduces the difficulty of post-processing.

[0030] In this invention, the molding process can employ conventional molding methods in the art, such as extrusion molding. Preferably, the molding process includes: mixing the ZSM-48 molecular sieve precursor, binder, and additives, followed by molding and calcination.

[0031] According to the present invention, preferably, the auxiliary agent is an inorganic acid and / or a polyhydroxy organic compound. Under the action of the above-mentioned auxiliary agent, the strength of the molded carrier precursor is improved, thereby facilitating subsequent ammonium exchange.

[0032] According to the present invention, preferably, the inorganic acid is nitric acid and / or hydrochloric acid.

[0033] In this invention, preferably, the polyhydroxy organic compound is a polysaccharide; more preferably, it is at least one of galactomannan, mannan, galactomannan, and cellulose ether; preferably, the cellulose ether is selected from at least one of methylcellulose, hydroxyethyl methylcellulose, and hydroxypropyl methylcellulose. When the additive is a polyhydroxy organic compound, it can achieve better physical colloidal properties when combined with a high-water-content ZSM-48 molecular sieve precursor, improving the strength of the carrier precursor. Especially when using an extrusion process for molding, it can further improve the strength of the carrier precursor, which is beneficial for subsequent processing.

[0034] In this invention, the binder can be selected from a wide range of options, and can be any conventional choice in the art. Preferably, the binder is selected from at least one of alumina, silica, boehmite, and silica sol, and more preferably boehmite. When boehmite is used as a binder, it forms a synergistic effect with the high-water-content ZSM-48 molecular sieve precursor, further improving the molding effect in the presence of the above-mentioned additives, which is beneficial to subsequent ammonium exchange.

[0035] In this invention, preferably, the amount of binder is 20-60 parts by weight, more preferably 30-50 parts by weight, relative to 100 parts by weight of ZSM-48 molecular sieve precursor on a dry basis, and the amount of additive is 2-20 parts by weight, more preferably 2-10 parts by weight. By adopting the above preferred embodiments, it is beneficial to give full play to the synergistic effect of additive, molecular sieve precursor and binder, thereby facilitating molding.

[0036] In this invention, preferably, in the molding process of step (1), the calcination conditions include: a calcination temperature of 300-600℃, preferably 500-600℃; and a calcination time of 2-10h, preferably 2-6℃.

[0037] In this invention, the ZSM-48 molecular sieve precursor can be prepared using conventional methods in the art, as long as the above-mentioned water content requirement is met. To further improve the yield of the hydroisomerized product and lower the product pour point, preferably, the preparation method of the ZSM-48 molecular sieve precursor includes:

[0038] (a) Provide a mixture containing a silicon source, an alkali source, an aluminum source, a template agent, water, a molecular sieve mother liquor, and seed crystals;

[0039] (b) The mixture is subjected to a crystallization reaction; the conditions for the crystallization reaction include: reacting at 20°C-50°C for 1-20 h, reacting at 50°C-80°C for 1-34 h, and then reacting at 80°C-180°C for 1-70 h.

[0040] (c) The mixture obtained from the crystallization reaction in step (b) is subjected to solid-liquid separation to obtain ZSM-48 molecular sieve precursor and molecular sieve mother liquor. The molecular sieve mother liquor is returned to step (a).

[0041] The method further includes, optionally, step (d), which includes: acidifying and depositing the molecular sieve mother liquor, followed by solid-liquid separation, and returning the filtrate to step (a).

[0042] In step (a), the mass percentage of the added seed crystals is not less than 10% of the mass percentage of the silicon source, where the silicon source is SiO2.

[0043] According to the present invention, the preferred preparation method described above, through the reuse of molecular sieve mother liquor and the introduction of seed crystals, facilitates the formation of small crystals. By employing a three-stage crystallization process at different temperatures, the progress and temperature of the crystallization reaction are strictly controlled. Compared to existing technologies, the crystallization reaction process set at low temperatures helps control crystal growth. The resulting ZSM-48 molecular sieve precursor exhibits an ellipsoidal morphology with a small aspect ratio, a major axis not exceeding 700 nm and an aspect ratio of 1-3:1, and a specific surface area not less than 200 m². 2 / g. The catalyst prepared further from the ZSM-48 molecular sieve precursor obtained by the above preparation method exhibits better diffusion performance of isomer products in the hydroisomerization reaction.

[0044] In this invention, it is understood that the ZSM-48 molecular sieve precursor can be the filter cake obtained by solid-liquid separation of the mixture obtained in step (b) crystallization reaction, or it can be the molecular sieve powder obtained after preliminary drying, as long as the moisture content meets the above requirements. The solid-liquid separation and drying methods are conventional operations in the art and will not be described in detail here.

[0045] Preferably, step (c) does not include drying the ZSM-48 molecular sieve precursor. Under the above preferred conditions, this helps to reduce the difficulty of post-processing, simplify the preparation process, and improve the strength of the carrier precursor after extrusion molding.

[0046] In this invention, those skilled in the art will understand that step (c) or steps (c) and (d) can be arbitrarily selected to obtain the molecular sieve mother liquor. When the method provided by this invention includes step (d), those skilled in the art will understand that the filtrate provides at least a portion of the molecular sieve mother liquor described in step (a).

[0047] Preferably, the preparation method further includes step (d). By adopting the above preferred embodiment, it is beneficial to obtain a ZSM-48 molecular sieve precursor containing small crystallites and a high specific surface area.

[0048] In this invention, the amount of seed crystals used is relatively large. Preferably, the mass percentage of the added seed crystals in step (a) is 10-30% of the mass percentage of the silicon source, and more preferably 20-30%. By adopting the above preferred embodiment, it is beneficial to form more crystal nuclei, and the prepared molecular sieve has the characteristic of small crystal grains.

[0049] According to the present invention, preferably, in the mixture described in step (a), the amount of the molecular sieve mother liquor is less than the amount of water. More preferably, the mass percentage of the molecular sieve mother liquor added in step (a) relative to the total mass of the molecular sieve mother liquor and water in step (a) is no more than 50%, more preferably 10-30%. In the above preferred cases, it is beneficial to form molecular sieves with small crystals and high specific surface area.

[0050] In this invention, preferably, the water is deionized water.

[0051] In this invention, the proportions of each raw material in step (a) can be adjusted according to actual needs. In order to improve the performance of the molecular sieve in the ZSM-48 molecular sieve precursor, and thus further improve the catalytic performance of the catalyst, preferably, the composition of each component in the mixture described in step (a) according to molar amounts satisfies the following relationship:

[0052] R / SiO2 = 0.01-0.4, preferably 0.01-0.08;

[0053] M + / SiO2 = 0.01-0.4, preferably 0.1-0.2;

[0054] Al2O3 / SiO2 = 0-0.02, preferably 0.01-0.015;

[0055] H2O / SiO2 = 5-30, preferably 5-20;

[0056] Wherein, SiO2 refers to SiO2 in the silicon source, R represents the template agent, and M... + Indicates the alkali source.

[0057] In this invention, the selection range for the silicon source, alkali source, aluminum source, and template agent in step (a) is relatively wide, and the above-mentioned raw materials are all conventional choices in the art. The above-mentioned raw materials should generally be mixed into a uniform gel by appropriate means, for example, by stirring.

[0058] According to the present invention, preferably, the silicon source is selected from at least one of silica sol, silica, fumed silica, water glass and tetraethyl orthosilicate; more preferably, silica sol.

[0059] According to the present invention, preferably, the alkali source is selected from alkaline metal salts, and more preferably at least one of sodium hydroxide, potassium hydroxide and calcium hydroxide; more preferably sodium hydroxide.

[0060] According to the present invention, preferably, the aluminum source is selected from at least one of boehmite, aluminum sulfate, aluminum isopropoxide and sodium aluminate; more preferably, it is boehmite.

[0061] According to the present invention, preferably, the template agent is selected from at least one of ethylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-anetanediamine, hexamethylammonium bromide, hexamethyldiamine chloride, and hexamethyldiamine hydroxide; more preferably, at least one of 1,6-hexanediamine, hexamethylammonium bromide, hexamethyldiamine chloride, and hexamethyldiamine hydroxide.

[0062] According to the present invention, preferably, the conditions for the crystallization reaction in step (b) include: reacting at 20°C-50°C for 6-20 h, reacting at 50°C-80°C for 12-34 h, and then reacting at 80°C-180°C for 48-70 h.

[0063] In this invention, preferably, in step (d), the acidification deposition includes: adding acid to the molecular sieve mother liquor to adjust the pH value to 5-7, preferably 5-6.5. The molecular sieve mother liquor obtained by the above preferred embodiment has the characteristic of having an appropriate amount of seed crystals, and further reuse in step (a) to participate in the reaction is beneficial to the formation of molecular sieves with high specific surface area.

[0064] Preferably, the acidification deposition time is 0.5-4 hours.

[0065] In this invention, there is no specific limitation on the type of acid mentioned in step (d), as long as the pH adjustment effect described above can be achieved. Preferably, the acid can be at least one of hydrochloric acid, nitric acid, ammonium nitrate and ammonium chloride.

[0066] In this invention, preferably, the seed crystal is a ZSM-48 molecular sieve seed crystal, wherein the molar ratio of silicon oxide to aluminum oxide in the ZSM-48 molecular sieve seed crystal is not less than 40, preferably 45-500. The silicon-aluminum ratio in the ZSM-48 molecular sieve seed crystal mainly depends on the feeding and preparation method of the silicon and aluminum sources in the raw materials.

[0067] Currently, in the XRD diffraction patterns of ZSM-48 molecular sieve raw powder synthesized using existing techniques and calcined, the peak positions are generally at 2θ angles of 7.5°, 21.2°, 22.8°, and 31.3°, with the highest peak at 21°-22° and a weaker peak at 7°-8°. Researchers of this invention have discovered that by employing a specific synthesis method, the preferred ZSM-48 molecular sieve seed crystals of this invention can be prepared. In the X-ray diffraction pattern of these seed crystals after calcination, the relative peak height of the diffraction peak at 2θ angle of 7°-8° is significantly higher than that of the diffraction peak at 7°-8° in molecular sieves obtained using existing techniques. Preferably, in the X-ray diffraction pattern of the calcined ZSM-48 molecular sieve seed crystals, using the peak height of the diffraction peak at 2θ angle of 21°-22° as a reference value, the peak height of the diffraction peak at 2θ angle of 7°-8° is not less than 70% of the reference value, preferably 75%-135%. For example, the lower limit of the peak height range of the 7°-8° diffraction peak can be 75%, 80%, 90% of the reference value, etc., and the upper limit of the peak height range of the 7°-8° diffraction peak can be 135%, 120%, 110%, 100% of the reference value, etc. Due to the influence of factors such as sample and instrument, the specific peak position of the 2θ angle in this invention may have a deviation of ±0.5°. The purpose of calcination is to remove impurities such as template agents in the molecular sieve powder to obtain more accurate XRD characterization results, and it will not have a substantial impact on the diffraction peaks in the XRD pattern of the molecular sieve itself. Therefore, the calcination conditions are based on the removal of impurities. For example, calcination can be carried out at 400-700℃ for 1-8 hours. In the preparation example of this invention, the ZSM-48 molecular sieve seed crystals were calcined at 600℃ for 4 hours before characterization.

[0068] In this invention, preferably, the method for preparing the seed crystal includes: contacting the reaction mixture under crystallization conditions, wherein the reaction mixture includes a silicon source, an alkali source, an aluminum source, a template agent, and water. The selection range of the silicon source, alkali source, aluminum source, and template agent can be the same as described above, and will not be repeated here; the types of silicon source, alkali source, aluminum source, and template agent selected can be the same as those used in the ZSM-48 molecular sieve precursor preparation process described above, or they can be different. Preferably, in the seed crystal preparation process, the content of each component in the reaction mixture satisfies the following relationship:

[0069] R / SiO2 = 0.01-0.5, more preferably 0.01-0.3;

[0070] H2O / SiO2 = 5-50, more preferably 5-20;

[0071] M + / SiO2 = 0.01-0.5, more preferably 0.01-0.15;

[0072] Al2O3 / SiO2 = 0-0.02; more preferably 0.01-0.017;

[0073] Where R represents the template agent, M + Indicates the alkali source.

[0074] In this invention, preferably, the preparation method of the seed crystals mainly includes three crystallization steps, and the temperature of each crystallization step is higher than the temperature of the previous crystallization step. Specifically, the crystallization temperature t1 of the first step satisfies 15℃≤t1<50℃, preferably carried out at room temperature, more preferably 20℃≤t1≤45℃, and the crystallization time of the first step is 5-24h, preferably 6-15h; the crystallization temperature t2 of the second step satisfies 50℃≤t2<100℃, preferably 60℃≤t2≤80℃, and the crystallization time of the second step is 0.5-36h, preferably 5-30h; the crystallization temperature t3 of the third step satisfies 100℃≤t3≤200℃, preferably 120℃≤t3≤190℃, and the crystallization time of the third step is 10-96h, preferably 20-80h. The seed crystals obtained by using the above preferred embodiments are beneficial for obtaining small-grain products in the above-mentioned method for preparing ZSM-48 molecular sieve precursors.

[0075] In this invention, preferably, the preparation process of the seed crystal further includes solid-liquid separation of the crystallization product to obtain the seed crystal.

[0076] In this invention, the ammonium exchange in step (2) can be carried out using conventional operations in the art. Preferably, the ammonium exchange includes: contacting the carrier precursor with an aqueous solution containing ammonium salt, followed by drying and calcination.

[0077] In this invention, preferably, the ammonium exchange conditions include: a temperature of 70-120℃, more preferably 80-100℃; and a time of 1-8 hours, more preferably 2-5 hours. Under these preferred conditions, it is beneficial to significantly reduce the oxide content in the molecular sieve product, further improve the isomerization performance of the catalyst, and lower the pour point of the product.

[0078] Preferably, the concentration of ammonium salt in the aqueous solution of the ammonium salt is 0.01-1 mol / L, more preferably 0.1-1 mol / L.

[0079] Preferably, the ammonium salt is selected from at least one of ammonium nitrate, ammonium sulfate, ammonium chloride, and ammonium acetate.

[0080] In this invention, the drying and calcination in step (2) can be carried out using conventional methods and conditions in the art. Preferably, the drying temperature is 80-150°C, more preferably 80-120°C, and the drying time is 2-10 hours, more preferably 2-6 hours.

[0081] Preferably, the calcination temperature is 300-600℃, more preferably 500-600℃, and the calcination time is 2-10h, more preferably 2-6h.

[0082] In this invention, step (3) can employ any method conventional in the art to introduce the active metal component, such as impregnation. Preferably, the method for introducing the active metal component in step (3) includes: impregnating the catalyst support with a solution of a soluble compound containing the active metal component, followed by drying and calcination to obtain the hydroisomerization catalyst.

[0083] In this invention, the impregnation can be carried out using conventional operations and conditions in the art. The concentration of the solution containing the soluble compound with active metal components is not particularly limited and can be adjusted according to actual needs, as is well known to those skilled in the art.

[0084] In this invention, preferably, the amount of the active metal component is such that, based on the total amount of the hydroisomerization catalyst, the content of the active metal component, in terms of elements, is 0.1-20% by weight, preferably 0.2-10% by weight. Under the above-mentioned preferred conditions, it is beneficial to further improve the catalytic activity of the catalyst.

[0085] In this invention, the types of soluble compounds containing active metal components are well known to those skilled in the art and can be conventionally selected in the field. Preferably, the soluble compounds containing active metal components are selected from at least one of tetraamminepalladium nitrate, tetraamminepalladium acetate, dichlorotetraamminepalladium, tetraammineplatinum nitrate, tetraammineplatinum acetate, and dichlorotetraammineplatinum.

[0086] According to the present invention, the drying and calcination in step (3) above can be carried out using conventional operations in the art. Preferably, the drying temperature is 80-120°C and the drying time is 2-6 hours.

[0087] Preferably, the roasting temperature is 400-500℃ and the roasting time is 2-6 hours.

[0088] In this invention, preferably, step (3) further includes reducing the hydroisomerization catalyst. Preferably, the reduction treatment includes: reducing and activating the active metal component in the presence of hydrogen. The conditions for reduction and activation include: a reduction temperature of 300-600℃, preferably 300-400℃; a reduction time of 2-10 h, preferably 2-6 h; and a hydrogen volume hourly space velocity of 0.1-10 h⁻¹. -1 Preferably 0.1-5h -1 .

[0089] A second aspect of the present invention provides a hydroisomerization catalyst prepared by the above preparation method.

[0090] The third aspect of the present invention provides a method for hydroisomerization of hydrocarbon oil, the method comprising: contacting feedstock oil with a hydroisomerization catalyst under hydroisomerization conditions, wherein the feedstock oil is selected from at least one of cracking tail oil, bio-jet fuel production feedstock, C5C6 isomerization feedstock, and Fischer-Tropsch synthesis wax, and the hydroisomerization catalyst is the hydroisomerization catalyst provided in the second aspect.

[0091] Preferably, the hydroisomerization conditions include: a temperature of 200-550℃, more preferably 240-420℃, and even more preferably 300-350℃; a pressure of 1-30 MPa, more preferably 2-20 MPa, and even more preferably 5-20 MPa; and a volume hourly space velocity of 0.1-5 h⁻¹. -1 Preferably 0.1-3h -1 More preferably 0.5-2h -1 The hydrogen-to-oil volume ratio is 50-3000, preferably 300-3000, and more preferably 400-600.

[0092] According to the present invention, by using the hydroisomerization catalyst provided in the present invention, the product yield is higher and the pour point is lower, which has significant effects.

[0093] The present invention will be described in detail below through embodiments.

[0094] In the following examples and comparative examples, the samples were characterized by XRD using a Bruker D5005 diffractometer with Cu Kα rays (λ = 0.154 nm), tube voltage 40 kV, tube current 30 mA, scanning range 5°-70°, step size 0.013°, and 1 step per second.

[0095] The morphology and size of the samples were characterized using a Hitachi S-4800 scanning electron microscope (SEM) with an accelerating voltage of 20 kV.

[0096] XPS characterization was performed using an ESCA Lab250 X-ray photoelectron spectroscopy system manufactured by Thermo Scientific. The excitation source was monochromatic Al Kα X-rays with a power of 300 W, and the baseline vacuum level in the analysis chamber was approximately 3 × 10⁻⁶. -7 Pa.

[0097] The pore structure parameters of the product, such as specific surface area and pore volume, were measured using nitrogen adsorption and BET methods.

[0098] The method for testing moisture content is as follows: Take a mass of M 烘干前The filter cake sample was placed in an oven and dried at 105-110℃ for about 6-8 hours until the sample weight no longer changed. The dried sample was then weighed and recorded as M. 烘干后 The moisture content of the filter cake can be calculated.

[0099] Filter cake moisture content (wt%) = (M 烘干前 -M 烘干后 ) / M 烘干前 3100%.

[0100] The test method for the product pour point shall be in accordance with the test method in SH / T 0771-2005.

[0101] The following preparation examples illustrate the preparation of seed crystals.

[0102] Preparation Example 1-1

[0103] Aluminum sulfate, hexamethyldiamine hydroxide (HMOH), sodium hydroxide, and deionized water were mixed in a certain proportion and stirred for 30 minutes. Silica sol was then added. The molar ratio of each substance was n(Al₂O₃):(HMOH):n(Na₂O₃). + The mixture of n(H₂O):n(SiO₂) = 0.01:0.03:0.3:8:1 was transferred to a crystallization vessel and crystallized at room temperature with stirring at 400 rpm for 6 hours; then crystallized at 80℃ for 24 hours, followed by crystallization at 180℃ for 48 hours. After crystallization, the mixture was filtered, and the solid product was dried at 120℃ for 6 hours to obtain seed crystal A1. Seed crystal A1 was calcined at 600℃ for 4 hours, and the XRD diffraction peaks were observed. Figure 1 The peak height of the diffraction peak at 7°-8° is 108% of the peak height of the diffraction peak at 21°-22°. The XRF analysis results and data such as specific surface area are shown in Table 1.

[0104] Preparation Examples 1-2

[0105] Sodium aluminate, hexamethyldiamine chloride (HMCl), sodium hydroxide, and deionized water were mixed in a certain proportion and stirred for 30 minutes. Silica sol was then added. The molar ratio of each substance was n(Al₂O₃):(HMCl):n(Na₂O₃). +The mixture of n(H₂O):n(SiO₂) = 0.004:0.03:0.3:21:1 was transferred into a crystallization vessel and crystallized at room temperature with stirring at 350 rpm for 12 h; then at 60 °C for 12 h, and then at 160 °C for 48 h. After crystallization, the mixture was filtered, and the product was dried at 120 °C for 6 h. The product obtained after filtration and drying was seed crystal A2. After calcination at 600 °C for 4 h, the peak height of the 7°-8° diffraction peak was 115% of the peak height of the 21°-22° diffraction peak in the XRD diffraction. The XRF analysis results and specific surface area data are shown in Table 1.

[0106] Preparation Examples 1-3

[0107] Sodium aluminate, hexamethyldiamine chloride (HMCl), sodium hydroxide, and deionized water were mixed in a certain proportion and stirred for 30 minutes. Silica sol was then added. The molar ratio of each substance was n(Al₂O₃):(HMCl):n(Na₂O₃). + The mixture of n(H₂O):n(SiO₂) = 0.004:0.03:0.3:21:1 was transferred to a crystallization vessel and crystallized at room temperature with stirring at 350 rpm for 12 hours. After crystallization, it was crystallized at 170℃ for 60 hours. The product obtained after filtration and drying was seed crystal A3. XRD analysis of seed crystal A3 after calcination at 600℃ for 4 hours is shown in the figure. Figure 2 The peak height of the diffraction peak at 7°-8° is 63% of that at 21°-22°. The XRF analysis results and data such as specific surface area are shown in Table 1.

[0108] The following preparation examples illustrate the preparation of ZSM-48 molecular sieve precursors.

[0109] Preparation Example 2-1

[0110] (1) Aluminum sulfate, hexamethyldiamine chloride (HMCl), sodium hydroxide, and deionized water containing molecular sieve mother liquor were mixed in a certain proportion and stirred for 30 minutes before adding silica sol. The molar ratio of each substance was n(Al2O3):(HMCl):n(Na) + ):n(H2O):n(SiO2)=0.01:0.03:0.3:10:1. The mass percentage of the molecular sieve mother liquor added in step (1) is 30% of the total mass of the molecular sieve mother liquor and water, and 25% of the mass of SiO2 is added as ZSM-48 seed crystal A1;

[0111] (2) Transfer the above mixture into a crystallization kettle, stir at room temperature for 6 hours, crystallize at 80°C for 24 hours, and crystallize at 170°C for 48 hours;

[0112] (3) After crystallization, filter the filter cake, which is the ZSM-48 molecular sieve precursor LB-1. Return the molecular sieve mother liquor to step (1). The water content of LB-1 is 15wt%.

[0113] 10 g of LB-1 was dried at 120℃ for 6 h to obtain ZSM-48 molecular sieve for testing. The results of XRF analysis of the silica-alumina ratio and specific surface area are shown in Table 1. Scanning electron microscope images are shown below. Figure 3 Its morphology is ellipsoidal, with a major axis of 300-700 nm and a major axis to minor axis ratio of approximately 1.1-1.4:1.

[0114] The remaining undried LB-1 was used as a precursor for ZSM-48 molecular sieve in subsequent catalyst preparation.

[0115] Preparation Example 2-2

[0116] (1) Sodium aluminate, hexamethyldiamine chloride (HMCl), sodium hydroxide, and deionized water containing molecular sieve mother liquor are mixed in a certain proportion and stirred for 30 minutes before adding silica sol. The molar ratio of each substance is n(Al2O3):(HMCl):n(Na) + ):n(H2O):n(SiO2)=0.004:0.03:0.3:20:1, the mass percentage of the molecular sieve mother liquor added in step (1) is 20% of the total mass of the molecular sieve mother liquor and water, and 15% of the mass of SiO2 is added as ZSM-48 seed crystal A2;

[0117] (2) The above mixture was transferred into a crystallization vessel and crystallized at 40°C for 12 hours, at 80°C for 10 hours, and at 170°C for 48 hours.

[0118] (3) After crystallization, filter the filter cake, which is the ZSM-48 molecular sieve precursor LB-2. Return the molecular sieve mother liquor to step (1). The water content of LB-2 is 20wt%.

[0119] 10 g of LB-2 was dried at 120℃ for 6 h to obtain ZSM-48 molecular sieve for testing. The results of XRF analysis of the silica-alumina ratio and the specific surface area are shown in Table 1. Its morphology is ellipsoidal, with a major axis of 300-600 nm and a major axis to minor axis ratio of approximately 1.1-1.4:1.

[0120] The remaining undried LB-2 was used as a precursor for ZSM-48 molecular sieve in subsequent catalyst preparation.

[0121] Preparation Examples 2-3

[0122] (1) Aluminum sulfate, hexamethyldiamine chloride (HMCl), sodium hydroxide, and deionized water containing molecular sieve mother liquor were mixed in a certain proportion and stirred for 30 minutes before adding silica sol. The molar ratio of each substance was n(Al2O3):(HMCl):n(Na) + ):n(H2O):n(SiO2)=0.0125:0.03:0.3:30:1. Add 25% of the mass of SiO2 ZSM-48 seed crystal A3. The mass percentage of the molecular sieve mother liquor added in step (1) to the total mass of the molecular sieve mother liquor and water is 20%;

[0123] (2) Transfer the above mixture into a crystallization kettle, stir at room temperature for 6 hours, crystallize at 80°C for 24 hours, and crystallize at 170°C for 48 hours;

[0124] (3) After crystallization, filter the filter cake, which is the ZSM-48 molecular sieve precursor LB-3. Return the molecular sieve mother liquor to step (1). The water content of LB-3 is 35wt%.

[0125] 10 g of LB-3 was dried at 120℃ for 6 h to obtain ZSM-48 molecular sieve for testing. The XRF analysis results and specific surface area data are shown in Table 1. Its morphology is rod-shaped with a length-to-short diameter ratio of about 7:1.

[0126] The remaining undried LB-3 was used as a precursor for ZSM-48 molecular sieve in subsequent catalyst preparation.

[0127] Table 1

[0128]

[0129] The following examples illustrate the preparation of hydroisomerization catalysts.

[0130] Example 1

[0131] 100 g of LB-1 (dry basis) was mixed with 58 g of boehmite (dry basis) and 2.5 g of methylcellulose, extruded into strips, and calcined at 580 °C for 3 h. The strips were then immersed in a 0.5 M ammonium chloride solution and exchanged at 90 °C for 2 h. After drying at 120 °C for 4 h, the mixture was calcined at 550 °C for 4 h to obtain the catalyst support.

[0132] 0.9 g of dichlorotetraammineplatinum (containing 57.3% Pt by mass) was added to 100 g of deionized water and stirred until homogeneous. 100 g of support was added to the above solution and impregnated at room temperature for 4 hours. Subsequently, the catalyst precursor was dried at 120°C for 4 hours. It was then calcined under an air stream at 450°C for 4 hours. The semi-finished catalyst was then reduced again in a hydrogen atmosphere at 400°C for 4 hours to obtain the final catalyst. The obtained catalyst was named CAT-1. The Pt loading in the catalyst was 0.5 wt%.

[0133] Example 2

[0134] 100g of LB-2 (dry basis) was mixed with 60g of boehmite (dry basis) and 3.6g of hydroxypropyl methylcellulose, extruded into strips, and calcined at 580°C for 3 hours. The strips were then immersed in a 0.5M ammonium chloride solution and exchanged at 90°C for 2 hours, dried at 120°C for 4 hours, and finally calcined at 550°C for 4 hours to obtain the catalyst support.

[0135] 0.4 g of dichlorotetraammineplatinum (containing 57.3% Pt by mass) and 0.7 g of dichlorotetraamminepalladium (containing 43.3% Pd by mass) were added to 100 g of deionized water and stirred until homogeneous. 100 g of support was added to the above solution and impregnated at room temperature for 4 hours. Subsequently, the catalyst precursor was dried at 120°C for 4 hours. It was then calcined under an air stream at 450°C for 4 hours. The semi-finished catalyst was then reduced again in a hydrogen atmosphere at 400°C for 4 hours to obtain the final catalyst. The obtained catalyst was named CAT-2. The catalyst contained 0.2 wt% Pt and 0.3 wt% Pd.

[0136] Example 3

[0137] 100 g of LB-3 (dry basis) was mixed with 55 g of boehmite (dry basis) and 2.4 g of hydroxyethyl methyl cellulose, extruded into strips, and calcined at 580 °C for 3 h. The strips were then immersed in a 0.5 M ammonium chloride solution and exchanged at 90 °C for 2 h, dried at 120 °C for 4 h, and finally calcined at 550 °C for 4 h to obtain the catalyst support.

[0138] 0.9 g of dichlorotetraammineplatinum (containing 57.3% Pt by mass) was added to 100 g of deionized water and stirred until homogeneous. 100 g of support was added to the above solution and impregnated at room temperature for 4 hours. Subsequently, the catalyst precursor was dried at 120°C for 4 hours. It was then calcined under an air stream at 450°C for 4 hours. The semi-finished catalyst was then reduced again in a hydrogen atmosphere at 400°C for 4 hours to obtain the final catalyst. The obtained catalyst was named CAT-3. The Pt loading in the catalyst was 0.5 wt%.

[0139] Example 4

[0140] 100 g of LB-1 (dry basis) was mixed with 50 g of pseudoboehmite (dry basis) and 2 g of nitric acid, shaped, and calcined at 580 °C for 3 h. Then, the support strip was placed in a 0.5 M ammonium chloride solution and exchanged at 90 °C for 2 h, dried at 120 °C for 4 h, and then calcined at 550 °C for 4 h to obtain the catalyst support.

[0141] 0.9 g of dichlorotetraammineplatinum (containing 57.3% Pt by mass) was added to 100 g of deionized water and stirred until homogeneous. 100 g of support was added to the above solution and impregnated at room temperature for 4 hours. Subsequently, the catalyst precursor was dried at 120°C for 4 hours. It was then calcined under an air stream at 450°C for 4 hours. The semi-finished catalyst was then reduced again in a hydrogen atmosphere at 400°C for 4 hours to obtain the final catalyst. The obtained catalyst was named CAT-4. The Pt loading in the catalyst was 0.5 wt%.

[0142] Example 5

[0143] The method was followed in Example 1, except that methylcellulose was not added during extrusion molding. The resulting catalyst was named CAT-5.

[0144] Example 6

[0145] The method was followed as in Example 1, except that after extrusion molding, the carrier strip was placed in a 0.05M ammonium chloride solution and exchanged at 70°C for 1 hour. The resulting catalyst was named CAT-6.

[0146] Example 7

[0147] The method was followed as in Example 1, except that after extrusion molding, the carrier strip was placed in a 0.1M ammonium chloride solution and exchanged at 90°C for 2 hours. The resulting catalyst was named CAT-7.

[0148] Example 8

[0149] 100 g of LB-1 (dry basis) was mixed with 60 g of pseudoboehmite (dry basis) and 3 g of nitric acid, extruded into strips, and calcined at 550 °C for 3 h. The support strips were then immersed in a 0.1 M ammonium chloride solution and exchanged at 80 °C for 2 h. After drying at 120 °C for 4 h, the mixture was calcined again at 550 °C for 3 h to obtain the catalyst support.

[0150] 0.5 g of dichlorotetraammineplatinum (containing 57.3% Pt by mass) was added to 100 g of deionized water and stirred until homogeneous. 100 g of support was added to the above solution and impregnated at room temperature for 4 hours. Subsequently, the catalyst precursor was dried at 120°C for 4 hours. It was then calcined under an air stream at 450°C for 4 hours. The semi-finished catalyst was then reduced again in a hydrogen atmosphere at 400°C for 4 hours to obtain the final catalyst. The obtained catalyst was named CAT-8. The Pt loading in the catalyst was 0.3 wt%.

[0151] Comparative Example 1

[0152] Following the method of Example 1, except that LB-1 was dried at 120°C for 4 hours, then calcined at 550°C for 4 hours. The resulting solid was placed in a 0.5M ammonium chloride solution, exchanged at 90°C for 2 hours, dried at 120°C for 4 hours, and then calcined at 550°C for 4 hours to obtain a solid product. Then, the solid product (based on 100 g of LB-1, dry basis) was extruded with 58 g of boehmite (dry basis) and calcined at 580°C for 3 hours to obtain a catalyst support. The obtained catalyst was named DCAT-1.

[0153] Comparative Example 2

[0154] Following the method of Example 1, except that LB-1 was dried at 120°C for 6 hours to reduce the moisture content of the filter cake to 5 wt%, and then shaped. The resulting catalyst was named DCAT-2.

[0155] Comparative Example 3

[0156] LB-1 was dried at 120℃ for 6 hours. 100g of LB-1 (dry basis) was mixed with 100g of boehmite, extruded, and dried to obtain the carrier.

[0157] One gram of dichlorotetraammineplatinum (containing 57.3% Pt by mass) was added to 100 grams of deionized water and stirred until homogeneous. One hundred grams of support was then added to the solution and impregnated at room temperature for 4 hours. Subsequently, the catalyst precursor was dried at 120°C for 4 hours. It was then calcined under an airflow at 450°C for 4 hours. The semi-finished catalyst was then reduced again in a hydrogen atmosphere at 400°C for 4 hours to obtain the final catalyst. This catalyst was named DCAT-3.

[0158] Catalyst evaluation

[0159] 200 mL of the above catalyst was loaded into a high-pressure hydrotreating reactor. Hydrocracking tail oil feedstock was injected into the reactor from top to bottom for reaction. The feedstock properties and reaction conditions are shown in Tables 2 and 3, respectively. After the reaction, the product was distilled to remove light components below 420 degrees Celsius. The components above 420 degrees Celsius were analyzed and their yields were calculated. The results are shown in Table 4.

[0160] Table 2 Properties of Hydrocracking Tail Oil

[0161] Analysis Project Analyze data Analytical methods <![CDATA[Density at 20 °C / (kg / m 3 )]]> 838.9 SH / T 0604-2000 <![CDATA[Kinematic viscosity / (mm 2 2s -1 )]]> GB / T 265-1988 40℃ 16.4 100℃ 3.8 Pour point / ℃ +40 SH / T 0771-2005 Nitrogen mass fraction (μg / g) 1.2 NB / SH / T 0704-2010 Sulfur mass fraction (μg / g) 2.1 SH / T 0842-2010 Distillation range / ℃ ASTM D-1160 IBP 411 10％ 434 50％ 467 90％ 510 FBP 544

[0162] Table 3 Reaction conditions

[0163]

[0164]

[0165] Table 4 Evaluation results at 330℃

[0166] catalyst Product yield / % Product Pour Point / °C Product viscosity index CAT-1 81 -21 126 CAT-2 80 -21 126 CAT-3 75 -17 122 CAT-4 81 -21 125 CAT-5 76 -17 121 CAT-6 77 -18 124 CAT-7 78 -18 123 CAT-8 80 -20 124 DCAT-1 72 -14 122 DCAT-2 70 -15 121 DCAT-3 71 -14 117

[0167] As can be seen from the results in Table 4, the preparation method of this invention has a short preparation process and is simple to operate. It can avoid steps such as drying and calcining of molecular sieves. By first forming and then exchanging ammonium, it is beneficial to reduce the difficulty of post-processing. The obtained hydroisomerization catalyst has a lower pour point and higher yield in the hydroisomerization reaction of hydrocarbon oils than the products obtained by the prior art, which has a significant effect.

[0168] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing a hydroisomerization catalyst, characterized in that, Includes the following steps: (1) The ZSM-48 molecular sieve precursor was shaped to obtain the carrier precursor; Specifically, based on the mass of the ZSM-48 molecular sieve precursor, the water content of the ZSM-48 molecular sieve precursor is not less than 15 wt%. (2) The precursor of the support is subjected to ammonium exchange to obtain a catalyst support; (3) Introduce an active metal component onto the catalyst support to obtain a hydroisomerization catalyst; The active metal component is Pt and / or Pd; The preparation method of the ZSM-48 molecular sieve precursor includes: (a) Provide a mixture containing a silicon source, an alkali source, an aluminum source, a template agent, water, a molecular sieve mother liquor, and seed crystals; (b) The mixture is subjected to a crystallization reaction; the conditions for the crystallization reaction include: reacting at 20°C-50°C for 1-20 h, reacting at 50°C-80°C for 1-34 h, and then reacting at 80°C-180°C for 1-70 h. (c) The mixture obtained from the crystallization reaction in step (b) is subjected to solid-liquid separation to obtain ZSM-48 molecular sieve precursor and molecular sieve mother liquor. The molecular sieve mother liquor is returned to step (a). The method further includes, optionally, step (d), which includes: acidifying and depositing the molecular sieve mother liquor, followed by solid-liquid separation, and returning the filtrate to step (a). In step (a), the mass percentage of the added seed crystals is 15-30% of the mass percentage of the silicon source, where the silicon source is SiO2. The seed crystal is a ZSM-48 molecular sieve seed crystal, and the molar ratio of silicon oxide to aluminum oxide in the ZSM-48 molecular sieve seed crystal is 45-500.

2. The preparation method according to claim 1, wherein, Based on the mass of the ZSM-48 molecular sieve precursor, the water content of the ZSM-48 molecular sieve precursor is 15-40 wt%.

3. The preparation method according to claim 1, wherein, The molding process includes mixing ZSM-48 molecular sieve precursor, binder and additives, followed by molding and calcination.

4. The preparation method according to claim 3, wherein, The additives are inorganic acids and / or polyhydroxy organic compounds.

5. The preparation method according to claim 4, wherein, The inorganic acid is nitric acid and / or hydrochloric acid.

6. The preparation method according to claim 4, wherein, The polyhydroxy organic compound is a polysaccharide.

7. The preparation method according to claim 6, wherein, The polyhydroxy organic compound is at least one of galactomannan, mannan, galactomannan and cellulose ether.

8. The preparation method according to claim 7, wherein, The cellulose ether is selected from at least one of methylcellulose, hydroxyethyl methylcellulose and hydroxypropyl methylcellulose.

9. The preparation method according to claim 3, wherein, The binder is selected from at least one of alumina, silica, boehmite, and silica sol.

10. The preparation method according to claim 9, wherein, The binder is boehmite.

11. The preparation method according to claim 3, wherein, The amount of the binder is 20-60 parts by weight relative to 100 parts by weight of ZSM-48 molecular sieve precursor on a dry basis, and the amount of the additive is 2-20 parts by weight.

12. The preparation method according to claim 11, wherein, The amount of the binder is 30-50 parts by weight relative to 100 parts by weight of ZSM-48 molecular sieve precursor on a dry basis, and the amount of the additive is 2-10 parts by weight.

13. The preparation method according to claim 3, wherein, The calcination conditions include: a calcination temperature of 300-600℃ and a calcination time of 2-10h.

14. The preparation method according to claim 1, wherein, Step (c) does not include drying the ZSM-48 molecular sieve precursor.

15. The preparation method according to claim 1, wherein, In step (a), the mass percentage of the added seed crystal relative to the mass percentage of the silicon source is 20-30%.

16. The preparation method according to claim 1, wherein, The mass percentage of the molecular sieve mother liquor added in step (a) is no more than 50% of the total mass of the molecular sieve mother liquor and water in step (a).

17. The preparation method according to claim 16, wherein, The mass percentage of the molecular sieve mother liquor added in step (a) is 10-30% of the total mass of the molecular sieve mother liquor and water in step (a).

18. The preparation method according to claim 1, wherein, The composition of each component in the mixture in step (a), calculated by molar amount, satisfies the following relationship: R / SiO2 = 0.01-0.4; M + / SiO2=0.01-0.4; Al2O3 / SiO2 = 0-0.02; H2O / SiO2 = 5-30; Wherein, SiO2 refers to SiO2 in the silicon source, R represents the template agent, and M... + Indicates the alkali source.

19. The preparation method according to claim 18, wherein, The composition of each component in the mixture in step (a), calculated by molar amount, satisfies the following relationship: R / SiO2 = 0.01-0.08; M + / SiO2=0.1-0.2; Al2O3 / SiO2 = 0.01-0.015; H2O / SiO2 = 5-20; Wherein, SiO2 refers to SiO2 in the silicon source, R represents the template agent, and M... + Indicates the alkali source.

20. The preparation method according to claim 1, wherein, The silicon source is selected from at least one of silica sol, silica, fumed silica, water glass, and tetraethyl orthosilicate.

21. The preparation method according to claim 1, wherein, The alkali source is an alkaline metal salt.

22. The preparation method according to claim 21, wherein, The alkali source is selected from at least one of sodium hydroxide, potassium hydroxide, and calcium hydroxide.

23. The preparation method according to claim 1, wherein, The aluminum source is selected from at least one of boehmite, aluminum sulfate, aluminum isopropoxide, and sodium aluminate.

24. The preparation method according to claim 1, wherein, The template agent is selected from at least one of ethylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-agentanediamine, hexamethylammonium bromide, hexamethyldiamine chloride, and hexamethyldiamine hydroxide.

25. The preparation method according to claim 1, wherein, The conditions for the crystallization reaction in step (b) include: reacting at 20℃-50℃ for 6-20h, reacting at 50℃-80℃ for 12-34h, and then reacting at 80℃-180℃ for 48-70h.

26. The preparation method according to claim 1, wherein, In step (d), the acidification deposition includes: adding acid to the molecular sieve mother liquor to adjust the pH value to 5-7.

27. The preparation method according to claim 26, wherein, In step (d), the acidification deposition includes: adding acid to the molecular sieve mother liquor to adjust the pH value to 5-6.

5.

28. The preparation method according to claim 1, wherein, The acidification deposition time is 0.5-4 hours.

29. The preparation method according to claim 1, wherein, In the X-ray diffraction pattern of the ZSM-48 molecular sieve seed crystals after calcination, the peak height of the diffraction peak with a 2θ angle of 21°-22° is taken as the reference value, and the peak height of the diffraction peak with a 2θ angle of 7°-8° is not less than 70% of the reference value.

30. The preparation method according to claim 29, wherein, In the X-ray diffraction pattern of the ZSM-48 molecular sieve seed crystals after calcination, the peak height of the diffraction peak with a 2θ angle of 21°-22° is taken as the reference value, and the peak height of the diffraction peak with a 2θ angle of 7°-8° is taken as 75%-135% of the reference value.

31. The preparation method according to claim 1 or 29, wherein, The method for preparing the seed crystals includes: contacting the reaction mixture under crystallization conditions, wherein the reaction mixture includes a silicon source, an alkali source, an aluminum source, a template agent, and water, and the crystallization conditions include: crystallizing sequentially at temperature t1 for 5-24 h, at temperature t2 for 0.5-36 h, and at temperature t3 for 10-96 h, wherein 15℃≤t1<50℃, 50℃≤t2<100℃, and 100℃≤t3≤200℃.

32. The preparation method according to claim 1, wherein, The ammonium exchange in step (2) includes contacting the carrier precursor with an aqueous solution containing ammonium salt, followed by drying and calcination.

33. The preparation method according to claim 32, wherein, The conditions for ammonium exchange include: a temperature of 70-120℃ and a time of 1-8h.

34. The preparation method according to claim 33, wherein, The conditions for ammonium exchange include: a temperature of 80-100℃ and a time of 2-5 hours.

35. The preparation method according to claim 32, wherein, The concentration of ammonium salt in the aqueous solution of the ammonium salt is 0.01-1 mol / L.

36. The preparation method according to claim 35, wherein, The concentration of ammonium salt in the aqueous solution of the ammonium salt is 0.1-1 mol / L.

37. The preparation method according to claim 32, wherein, The ammonium salt is selected from at least one of ammonium nitrate, ammonium sulfate, ammonium chloride, and ammonium acetate.

38. The preparation method according to claim 32, wherein, The drying temperature is 80-150℃, and the drying time is 2-10 hours.

39. The preparation method according to claim 32, wherein, The roasting temperature is 300-600℃, and the roasting time is 2-10h.

40. The preparation method according to claim 1, wherein, The method for introducing the active metal component in step (3) includes: impregnating the catalyst support with a solution of a soluble compound containing the active metal component, and then drying and calcining it to obtain the hydroisomer catalyst.

41. The preparation method according to claim 1, wherein, The amount of the active metal component is such that, based on the total amount of the hydroisomerization catalyst, the content of the active metal component, expressed as an element, is 0.1-20% by weight.

42. The preparation method according to claim 41, wherein, The amount of the active metal component is such that, based on the total amount of the hydroisomerization catalyst, the content of the active metal component is 0.2-10% by weight in terms of elements.

43. The preparation method according to claim 40, wherein, The soluble compound containing the active metal component is selected from at least one of tetraamminepalladium nitrate, tetraamminepalladium acetate, dichlorotetraamminepalladium, tetraammineplatinum nitrate, tetraammineplatinum acetate, and dichlorotetraammineplatinum.

44. The preparation method according to claim 40, wherein, The drying temperature is 80-120℃, and the drying time is 2-6 hours.

45. The preparation method according to claim 40, wherein, The roasting temperature is 400-500℃, and the roasting time is 2-6 hours.

46. ​​The hydroisomerization catalyst prepared by the preparation method according to any one of claims 1-45.

47. A method for hydroisomerization of hydrocarbon oil, the method comprising: Under hydroisomerization conditions, feedstock oil is contacted with a hydroisomerization catalyst, wherein the feedstock oil is selected from at least one of cracked tail oil, bio-jet fuel production feedstock, C5C6 isomerization feedstock, and Fischer-Tropsch synthesis wax, and the hydroisomerization catalyst is the hydroisomerization catalyst according to claim 46.

48. The method according to claim 47, wherein, The hydroisomerization conditions include: a temperature of 200-550℃, a pressure of 1-30 MPa, and a volume hourly space velocity of 0.1-5 h⁻¹. -1 The hydrogen-to-oil volume ratio is 50-3000.

49. The method according to claim 48, wherein, The hydroisomerization conditions include: a temperature of 240-420℃, a pressure of 2-20 MPa, and a volume hourly space velocity of 0.1-3 h⁻¹. -1 The hydrogen-to-oil volume ratio is 300-3000.

50. The method according to claim 49, wherein, The hydroisomerization conditions include: a temperature of 300-350℃, a pressure of 5-20 MPa, and a volume hourly space velocity of 0.5-2 h⁻¹. -1 The hydrogen-to-oil volume ratio is 400-600.

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