ZSM-48 molecular sieve and preparation method therefor, isodewaxing catalyst and preparation method therefor, and the use thereof

Abstract

A ZSM-48 molecular sieve and a preparation method therefor, an isodewaxing catalyst and a preparation method therefor, and the use thereof. The preparation method for the ZSM-48 molecular sieve comprises: uniformly mixing an aluminum source, a silicon source, an alkali source, a crystallization inducer, a template agent, deionized water, a pore-forming agent and a charge balancing agent; then successively performing on an obtained gel solution pre-crystallization at 70-90℃ for 2-6 h, crystallization at 120-140℃ for 2-6 h and crystallization at 140-170℃ for 10-48 h; washing a crystallized product, drying same and roasting same; and mixing an obtained molecular sieve precursor with an ammonium salt, washing same, drying same and roasting same to obtain the ZSM-48 molecular sieve. Carrier granules of the isodewaxing catalyst contain the ZSM-48 molecular sieve. The molecular sieve has uniformly distributed acidic sites, a relatively small grain size and a relatively high total BET specific surface area. The isodewaxing catalyst has a relatively high reaction efficiency and isomerization conversion rate and a low cracking rate.

Description

ZSM-48 molecular sieve and preparation method thereof, isomerization dewaxing catalyst and preparation method and application thereof

[0001] This application claims priority to the Chinese patent application filed with the Patent Office of China on August 7, 2023, with application number 202310987321.4 and invention name “ZSM-48 molecular sieve and its preparation method, isomerized dewaxing catalyst and its preparation method and application”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present invention relates to a ZSM-48 molecular sieve and a preparation method thereof, an isomerization dewaxing catalyst and a preparation method and application thereof, belonging to the technical field of molecular sieve catalysts. Background Art

[0003] Demand for Group II and III base oils produced using isomerization dewaxing technology is increasing annually. Lubricant base oils are a specialty product for oil refining and a key component of refinery profitability. Isomerization dewaxing catalysts are primarily used in lubricant hydroisomerization, for isomerization dewaxing, supplemental refining, and white oil hydrogenation catalyst preparation. The key technology in isomerization dewaxing is the preparation of precious metal catalysts. For bifunctional catalysts with high isomerization selectivity and low cracking activity, the active metal is typically precious metals such as Pt and Pd, which dehydrogenate and hydrogenate alkanes or alkenes. Molecular sieves are primarily used as supports, providing acidity, pore restriction, and shape selectivity during the isomerization reaction. Aluminophosphate and silica-alumino molecular sieves with one-dimensional straight pore structures are commonly used, with SAPO-11, ZSM-22, ZSM-23, ZSM-48, and ZSM-12 being typical examples. Their pore confinement and acidic properties determine their ability to convert different feedstock molecules and the resulting product structures.

[0004] The following briefly introduces some prior arts related to the present invention:

[0005] CN 112934258 A discloses a composite molecular sieve, a preparation method thereof, a hydroisomerization catalyst, and a method for hydroisomerizing Fischer-Tropsch oil. The composite molecular sieve has a core-shell structure comprising an inner core and an outer shell coating the inner core, wherein the inner core contains a modified ZSM-48 molecular sieve and the outer shell contains an MCM-41 molecular sieve. The outer shell comprises 0.1-50% by weight, and the inner core comprises 50-99.9% by weight, based on the total weight of the composite molecular sieve. The hydroisomerization catalyst prepared from the composite molecular sieve is used in the hydroisomerization reaction of Fischer-Tropsch oil, exhibiting improved isomerization selectivity and capable of producing high-quality, high-yield lubricant base oil. However, the defects of this technology or the shortcomings of the present invention include: the composite molecular sieve catalyst preparation process is more complicated; the coating thickness and uniformity of the MCM-41 molecular sieve outside the ZSM-48 molecular sieve cluster are difficult to accurately control; and the pore dispersion and acidity control are difficult.

[0006] CN 105214718 A discloses a method for preparing an isodewaxing catalyst. This method involves modifying the catalyst support by adding a certain amount of a soluble alkaline earth metal salt solution during catalyst support formation. A solvent-thermal ion exchange method is employed in the step of loading the active metal component, wherein the solvent-thermal ion exchange method replaces water with a solvent, and the active component is loaded onto the catalyst support via ion exchange under certain temperature and pressure conditions. This prior art also provides an isodewaxing catalyst prepared by the above method. This catalyst is used for isodewaxing lubricating oil fractions to produce low-pour-point, high-viscosity-index lubricating oil base oil. The catalyst exhibits moderate catalyst acidity, high metal dispersion, high isodewaxing reaction activity and selectivity, and a low pour point and high yield of the lubricating oil base oil. However, this technology has drawbacks or shortcomings relative to the present invention, including: loading the active component onto the catalyst support via solvent-thermal ion exchange under certain temperature and pressure conditions, using volatile small-molecule alcohols as solvents, which increases costs and makes the process difficult to control.

[0007] CN 105709817 A discloses an isomerization dewaxing catalyst and its preparation method. The preparation method comprises first embedding a small-grain MTT-type molecular sieve loaded with a hydrogenation active component in an organic starch or polyvinyl alcohol, then uniformly mixing it with a precursor of a high-temperature-resistant inert oxide, forming it, drying it, and calcining it to obtain the isomerization dewaxing catalyst. The catalyst provided by this prior art is suitable for the isomerization dewaxing process of lubricating oil fractions. Since the amount of molecular sieve used in the catalyst is significantly reduced, not only is the catalyst production cost significantly reduced, but the discharge of difficult-to-treat wastewater during the molecular sieve synthesis process is also avoided, and the catalyst has the characteristics of high yield and low pour point of the target product. However, the defects of this technology or the shortcomings relative to the present invention include: the MTT-type molecular sieve is embedded in the organic starch or polyvinyl alcohol, and carbon deposits are generated during the calcination of the organic material, causing blockage of the molecular sieve pores. In addition, the selected organic material has a large molecular weight, and embedding the molecular sieve in it is not conducive to metal dispersion.

[0008] CN 105800635 A discloses a method for preparing a ZSM-48 molecular sieve having a hierarchical mesoporous-microporous structure. The method comprises homogenizing and mixing an aluminum source, sodium hydroxide, and deionized water, adding a template and a silicon source, homogenizing and mixing again, and then adding starch to obtain an initial gel mixture; aging the initial gel mixture, crystallizing it, separating, washing, drying, and calcining the crystallized solid product to obtain a ZSM-48 molecular sieve having a hierarchical mesoporous-microporous structure. This preparation method has the advantages of being simple, environmentally friendly, and inexpensive. However, the defects of this technology or the shortcomings of the present invention include: using starch as a mesoporous pore-forming agent, the molecular weight is relatively large, and it is easy to coke and block the pore openings during the calcination process; and the crystallization time is as long as 4-15 days, which is a long crystallization time.

[0009] CN 115108563 A discloses a ZSM-48 molecular sieve and a preparation method thereof, a low-carbon alkane isomerization catalyst, and its preparation method and application. The preparation method of the ZSM-48 molecular sieve comprises: (1) mixing an aluminum source, an alkali source, a template, and deionized water to obtain a solution, then adding a pore-expanding agent, a seed crystal, and a silicon source to the solution to obtain a precursor gel; (2) crystallizing the precursor gel, and then subjecting the crystallized product to an alkali treatment; wherein the pore-expanding agent is selected from carbon nanotubes and / or carbon nanofibers. The alkane isomerization catalyst prepared using the ZSM-48 molecular sieve obtained above has higher isoparaffin selectivity and yield in alkane isomerization reactions, especially in low-carbon alkane isomerization reactions, and has a wide range of applications, particularly for the isomerization of C5-C12 hydrocarbons to increase the octane number of gasoline. However, the defects of this technology or the shortcomings relative to the present invention include: the product is subjected to alkali treatment after crystallization, the process is complicated and difficult to control, the wastewater discharge volume increases, and the pore-expanding agent carbon nanotubes and / or carbon nanofibers are prone to coking and blocking the pores during the calcination process.

[0010] In summary, at present, the existing technology generally uses pore-forming agents such as starch, polyvinyl alcohol, and carbon nanotubes that do not participate in the synthesis of molecular sieves. However, the molecular weight of these pore-forming agents is large, the pore-forming effect is limited, and they are prone to coking and blocking the pores during the roasting process; or the molecular sieve is embedded in organic starch or polyvinyl alcohol, and coking produces carbon deposits during the roasting process of the organic matter, causing the molecular sieve pores to be blocked. The selected organic matter has a large molecular weight, and embedding the molecular sieve therein is not conducive to metal dispersion; in addition, the preparation process of the composite molecular sieve catalyst provided in the existing technology is more complicated. For example, the thickness and uniformity of the other molecular sieves coated on the outside of the ZSM-48 molecular sieve cluster are difficult to accurately control, and the pore dispersion and acidity are difficult to control.

[0011] Therefore, providing a new ZSM-48 molecular sieve and its preparation method, an isomerization dewaxing catalyst and its preparation method and application has become a technical problem that needs to be solved urgently in this field.

[0012] Summary of the Invention

[0013] In order to solve the above-mentioned shortcomings and deficiencies, one object of the present invention is to provide a method for preparing ZSM-48 molecular sieve.

[0014] Another object of the present invention is to provide a ZSM-48 molecular sieve, which is prepared by the above-mentioned preparation method of ZSM-48 molecular sieve.

[0015] Another object of the present invention is to provide an isodewaxing catalyst, the carrier particles of which contain the above-mentioned ZSM-48 molecular sieve.

[0016] Another object of the present invention is to provide a method for preparing the above-mentioned isomerization dewaxing catalyst.

[0017] The last object of the present invention is to provide the use of the above-mentioned isomerization dewaxing catalyst in the preparation of lubricating oil by hydroisomerization of heavy raw materials.

[0018] In order to achieve the above objectives, on the one hand, the present invention provides a method for preparing ZSM-48 molecular sieve, wherein the method for preparing ZSM-48 molecular sieve comprises:

[0019] Step 1: uniformly mix an aluminum source, a silicon source, an alkali source, a crystallization inducing agent, a template agent, deionized water, a pore-forming agent, and a charge balancing agent to obtain a gel solution;

[0020] Among them, the aluminum source in terms of Al2O3, -The molar ratio of the alkali source, template, H2O and silicon source calculated as SiO2 is 0.0025-0.02:0.006-0.38:0.11-1.5:10-50:1, preferably 0.005-0.01:0.015-0.25:0.2-1:20-40:1;

[0021] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.01-0.2:1, preferably 0.01-0.1:1;

[0022] The molar ratio of the crystallization inducing agent calculated as M2O to the silicon source calculated as SiO2 is 0.002-0.2:1, preferably 0.005-0.03:1, wherein M is one or more alkali metals;

[0023] The molar ratio of the charge balance agent to H2O is 0.1-1:1, preferably 0.2-0.5:1;

[0024] Step 2: pre-crystallizing the gel solution at 70-90° C. for 2-6 hours, crystallizing at 120-140° C. for 2-6 hours, and crystallizing at 140-170° C. for 10-48 hours to obtain a crystallized product;

[0025] Step 3: washing, drying and calcining the crystallized product to obtain a molecular sieve precursor;

[0026] Step 4: The molecular sieve precursor is mixed with an ammonium salt, and then washed, dried and calcined to obtain the ZSM-48 molecular sieve.

[0027] As a specific embodiment of the preparation method described above of the present invention, wherein the aluminum source comprises one or a combination of aluminum sulfate, sodium metaaluminate, aluminum nitrate, etc., preferably aluminum sulfate;

[0028] The silicon source includes one or a combination of silica sol, white carbon black, ethyl orthosilicate, etc., preferably silica sol;

[0029] The alkali source includes NaOH and / or KOH and the like.

[0030] As a specific embodiment of the above preparation method of the present invention, wherein the template comprises a first template and a second template, and the molar ratio of the first template to the second template is 1-400:1, preferably 50-150:1.

[0031] As a specific embodiment of the preparation method described above of the present invention, wherein the first template agent includes one or a combination of cyclohexylamine, dodecylamine, 1,6-hexanediamine, 1,8-octanediamine and benzylamine, etc., preferably 1,6-hexanediamine, and the second template agent includes one or a combination of hexamethylammonium chloride, hexamethylammonium bromide, ammonium oxalate, ammonium acetate and benzyltriethylammonium bromide, etc., preferably hexamethylammonium chloride.

[0032] As a specific embodiment of the above preparation method of the present invention, the ammonium salt includes one or a combination of ammonium chloride, ammonium nitrate and ammonium sulfate, and is preferably ammonium chloride.

[0033] As a specific embodiment of the above preparation method of the present invention, the crystallization inducing agent includes one or a combination of sodium chloride, potassium chloride, sodium sulfate, potassium sulfate, etc., preferably potassium chloride.

[0034] As a specific embodiment of the preparation method described above, the pore-forming agent includes one or a combination of P123, Triton-100, polyhexamethylene biguanide, ammonium chloride, polyvinyl alcohol, etc., preferably P123.

[0035] As a specific embodiment of the above preparation method of the present invention, the relative molecular weight of the P123 is 4000-8000.

[0036] As a specific embodiment of the preparation method described above, the charge balancer includes one or a combination of alcohol charge balancers such as glycerol, ethylene glycol, isopropyl alcohol, propanol, 2-butanol, etc., preferably glycerol.

[0037] As a specific embodiment of the above-mentioned preparation method of the present invention, in step 1, the amount of the pore-forming agent is within 5 wt % of the total weight of the gel solution.

[0038] As a specific embodiment of the preparation method described above, in step 1, the amount of the crystallization inducer calculated as M2O is within 5 wt% of the total weight of the gel solution.

[0039] As a specific embodiment of the above preparation method of the present invention, wherein, in step 1, the uniform mixing is carried out at 40-60°C.

[0040] As a specific embodiment of the above-mentioned preparation method of the present invention, in step 3, the calcination is performed at 500-600° C. for 6-30 hours.

[0041] As a specific embodiment of the above preparation method of the present invention, in step 4, the mixing is performed at 70-80° C. for 4-6 hours.

[0042] As a specific embodiment of the above preparation method of the present invention, wherein, in step 4, the calcination is performed at 500-600° C. for 6-40 hours, preferably 6-30 hours.

[0043] In the preparation method of the ZSM-48 molecular sieve provided by the present invention, washing, drying, etc. are all conventional operations, and the washing and drying operation steps and the process parameters involved can be reasonably adjusted according to the actual operation needs on site.

[0044] On the other hand, the present invention further provides a ZSM-48 molecular sieve, wherein the ZSM-48 molecular sieve is prepared by the above-mentioned preparation method of the ZSM-48 molecular sieve.

[0045] As a specific embodiment of the ZSM-48 molecular sieve described above, the ZSM-48 molecular sieve has a crystal length of 0.1-0.5 μm, a crystal diameter of 50-100 nm, and an axis-to-diameter ratio of 2-10. In the present invention, the axis-to-diameter ratio is the ratio of the molecular sieve crystal length to the cross-sectional width.

[0046] On the other hand, the present invention also provides an isodewaxing catalyst, comprising carrier particles and precious metal active components loaded on the carrier particles, wherein the carrier particles contain the above-mentioned ZSM-48 molecular sieve, and the loading amount of the precious metal active components is 0.1-0.5 wt% of the mass of the carrier particles.

[0047] As a specific embodiment of the above-mentioned isomerization dewaxing catalyst of the present invention, the noble metal active component includes platinum and / or palladium.

[0048] As a specific embodiment of the above-mentioned isodewaxing catalyst of the present invention, the carrier particles are prepared by uniformly mixing the ZSM-48 molecular sieve, alumina, titanium dioxide, an acid solution, a binder, and deionized water, followed by extrusion, drying, and calcination;

[0049] The mass ratio of ZSM-48 molecular sieve, alumina, titanium dioxide, acid solution, binder and deionized water is 1:0.3-9:0.01-0.5:0.01-0.6:0.3-1:0.2-1, preferably 1:0.5-2:0.02-0.05:0.02-0.5:0.5-0.8:0.5-0.8.

[0050] As a specific embodiment of the above-mentioned isodewaxing catalyst of the present invention, the adhesive includes sesbania powder and / or methyl cellulose, etc., preferably sesbania powder; the acid solution includes nitric acid or phosphoric acid solution with a concentration of 5-15wt%, etc., preferably nitric acid; the alumina is common alumina such as pseudo-boehmite.

[0051] As a specific embodiment of the above-mentioned isodewaxing catalyst of the present invention, the carrier particles are prepared by uniformly mixing the ZSM-48 molecular sieve, alumina, titanium dioxide, acid solution, binder and deionized water, followed by extrusion, drying and calcination at 400-500°C for 6-14 hours.

[0052] In another aspect, the present invention further provides a method for preparing the above-mentioned isodewaxing catalyst, wherein the preparation method comprises:

[0053] Step (1): dissolving a noble metal salt in a mixture of water, alcohol and ligand and mixing them uniformly to obtain a noble metal precursor solution;

[0054] Step (2): impregnating the carrier particles in a noble metal precursor solution, and then drying and calcining the impregnated product to obtain the isomerization dewaxing catalyst.

[0055] As a specific embodiment of the above-mentioned method for preparing the isomerization dewaxing catalyst of the present invention, the precious metal salt includes one or a combination of chloroplatinic acid hexahydrate, palladium chloride, platinum dichloride, ammonium hexachloroplatinate, etc., preferably chloroplatinic acid hexahydrate.

[0056] In a specific embodiment of the above-described method for preparing an isodewaxing catalyst of the present invention, the ligand comprises one or a combination of sorbic acid, salicylic acid, niacinamide, lactic acid, citric acid, hyaluronic acid, and the like, and the molar ratio of the ligand to the precious metal atom is 6-18:1. During the preparation of the isodewaxing catalyst, the ligand complexes with the precious metal atom and is loaded on the carrier, which facilitates the dispersion of the precious metal atoms. The presence of the ligand can also, to a certain extent, prevent the precious metal from aggregating into large particles.

[0057] As a specific embodiment of the above-mentioned method for preparing the isomerization dewaxing catalyst of the present invention, the alcohol includes one or a combination of ethanol, propanol, isopropanol, glycerol, etc., preferably glycerol, and the mass ratio of water to alcohol is 50-1:1, preferably 20-10:1.

[0058] As a specific embodiment of the above-mentioned method for preparing the isodewaxing catalyst of the present invention, in step (1), the uniform mixing is performed at 30-60° C. for 2-6 hours.

[0059] As a specific embodiment of the above-mentioned method for preparing the isodewaxing catalyst of the present invention, in step (2), the calcination is carried out in an air atmosphere at 400-600°C for 4-14 hours, preferably at 400-500°C for 6-14 hours.

[0060] In the preparation method of the isodewaxing catalyst provided by the present invention, extrusion, drying, and baking are all conventional operations, and the operating steps of extrusion, drying, and baking and the process parameters involved can be reasonably adjusted according to actual on-site operation needs.

[0061] In the final aspect, the present invention also provides the use of the above-mentioned isodewaxing catalyst in the preparation of lubricating oil by hydroisomerization of heavy feedstock.

[0062] As a specific embodiment of the above application of the present invention, the heavy feedstock includes FT wax or hydrocracking tail oil.

[0063] Compared with the prior art, the beneficial technical effects achieved by the present invention include:

[0064] 1) The present invention uses a crystallization inducer when preparing the ZSM-48 molecular sieve. The crystallization inducer can induce the rapid formation of more crystal nuclei, greatly shorten the crystallization time, and reduce the grain size, that is, form more small-grain molecular sieves, with a grain length of only 0.1-0.5 μm. When the isomerization dewaxing catalyst (whose carrier particles contain the above-mentioned ZSM-48 molecular sieve) is used for hydroisomerization to prepare lubricating oil, it is beneficial for the product to diffuse out of the pores, thereby reducing the occurrence of cracking reactions;

[0065] 2) The present invention uses alcohols as charge balancing agents when preparing ZSM-48 molecular sieves. Alcohols are soluble in water and have a molecular size between that of water molecules and structure-directing agents (i.e., templates, including first and second templates). They can enter the pores and can replace some water molecules during the synthesis of the molecular sieve to support / fill the pores. The hydroxyl groups contained in the alcohols form hydrogen bonds with the inorganic anion skeleton of the molecular sieve, maintaining the charge balance in the pores. This allows more water molecules in the crystallization system to act as solvents (equivalent to an increase in the water phase), enhancing fluidity and uniformly dispersing the crystals in the solvent, making it easier to form small-crystal molecular sieves, which is conducive to the formation of small crystals. In addition, the use of alcohols as charge balancing agents does not change the pH value of the system, thereby avoiding the formation of stray crystals. The added charge balancing agent also facilitates the uniform distribution of the acid sites of the molecular sieve. When the isomerization dewaxing catalyst (whose carrier particles contain the above-mentioned ZSM-48 molecular sieve) is used for hydroisomerization to prepare lubricating oil, the reaction efficiency can be improved.

[0066] 3) The present invention uses a pore-forming agent when preparing the ZSM-48 molecular sieve, which can directly form mesopores and micropores during the molecular sieve synthesis process. When the isomerization dewaxing catalyst (whose carrier particles contain the above-mentioned ZSM-48 molecular sieve) is used to prepare lubricating oil by hydroisomerization, it is beneficial for the reactants and products to diffuse in the pores, thereby improving the diffusion efficiency of the reactants and products, improving the reaction efficiency and isomerization conversion rate, reducing the cracking rate, and reducing the amount of molecular sieve used in the catalyst;

[0067] 4) When preparing the ZSM-48 molecular sieve of the present invention, the gel solution is pre-crystallized at 70-90° C. for 2-6 hours, crystallized at 120-140° C. for 2-6 hours, and crystallized at 140-170° C. for 10-48 hours. The first stage of crystallization forms a primary structure, and the second stage of crystallization forms a large number of crystal nuclei, which is conducive to rapid growth into small grains under the temperature conditions of the third stage of crystallization. The small grain molecular sieve has a short pore length, which is conducive to the rapid diffusion of reaction products from the pores and reduces secondary cracking reactions.

[0068] 5) The preparation method of the present invention can directly synthesize short-axis ZSM-molecular sieves, shorten the pore length, and significantly improve the reaction efficiency when the isomerization dewaxing catalyst (whose carrier particles contain the above-mentioned ZSM-48 molecular sieve) is used for hydroisomerization to prepare lubricating oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0070] FIG1 is an XRD diagram of molecular sieve A1 provided in Example 1 of the present invention.

[0071] FIG2 is a SEM image of the molecular sieve A1 provided in Example 1 of the present invention.

[0072] FIG3 is an XRD diagram of molecular sieve A7 provided in Comparative Example 1.

[0073] FIG4 is a SEM image of the molecular sieve A7 provided in Comparative Example 1.

[0074] FIG5 is an XRD diagram of molecular sieve A9 provided in Comparative Example 3.

[0075] FIG6 is a SEM image of the molecular sieve A9 provided in Comparative Example 3.

[0076] FIG7 is an XRD diagram of molecular sieve A11 provided in Comparative Example 5.

[0077] FIG8 is an XRD pattern of molecular sieve A12 provided in Comparative Example 6. DETAILED DESCRIPTION

[0078] It should be noted that the term "comprise" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or are inherent to these processes, methods, products or apparatus.

[0079] The "range" disclosed in the present invention is given in the form of a lower limit and an upper limit. It can be one or more lower limits, and one or more upper limits respectively. A given range is defined by selecting a lower limit and an upper limit. The selected lower limit and upper limit define the boundaries of a particular range. All ranges defined in this way are combinable, i.e., any lower limit can be combined with any upper limit to form a range. For example, a range of 60-120 and 80-110 is listed for a particular parameter, and it is understood that a range of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​listed are 1 and 2, and the maximum range values ​​listed are 3, 4, and 5, then the following ranges can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5.

[0080] In the present invention, unless otherwise specified, the numerical range "ab" is an abbreviation for any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" are listed in this invention, and "0-5" is merely an abbreviation for these numerical combinations.

[0081] In the present invention, unless otherwise specified, all embodiments and preferred embodiments mentioned in the present invention can be combined with each other to form a new technical solution.

[0082] In the present invention, unless otherwise specified, all technical features and preferred features mentioned in the present invention can be combined with each other to form a new technical solution.

[0083] In the present invention, unless otherwise specified, all steps mentioned herein may be performed sequentially or randomly, but are preferably performed sequentially. For example, the method comprising steps (a) and (b) indicates that the method may comprise steps (a) and (b) performed sequentially, or may comprise steps (b) and (a) performed sequentially. For example, the method further comprising step (c) indicates that step (c) may be added to the method in any order, for example, the method may comprise steps (a), (b) and (c), or may comprise steps (a), (c) and (b), or may comprise steps (c), (a) and (b), etc.

[0084] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with the attached table, drawings and examples. The following embodiments are some embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. If specific conditions are not specified in the examples, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0085] ZSM-48 molecular sieve examples and comparative examples

[0086] Example 1

[0087] This embodiment provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0088] Step 1: 3.22 g of aluminum sulfate, 36 g of silica sol (40 wt% solid content), 0.06 g of NaOH, 0.06 g of NaCl, 4.7 g of hexamethonium bromide, 1.4 g of cyclohexylamine, 24 g of deionized water, 0.74 g of Triton X-100, and 24 g of glycerol were mixed at 40° C. to obtain a gel solution;

[0089] Among them, the aluminum source in terms of Al2O3, - The molar ratio of the alkali source, template, H2O and silicon source calculated as SiO2 is 0.02:0.006:0.11:10:1;

[0090] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.01:1;

[0091] The molar ratio of the crystallization inducer calculated as Na2O to the silicon source calculated as SiO2 is 0.002:1;

[0092] The molar ratio of charge balancer to H2O was 0.1:1;

[0093] The molar ratio of cyclohexylamine to hexamethylammonium bromide is 1:1;

[0094] Step 2: pre-crystallizing the gel solution at 70° C. for 2 h, crystallizing at 120° C. for 2 h, and crystallizing at 140° C. for 48 h to obtain a crystallized product;

[0095] Step 3: washing, drying and calcining the crystallized product at 500° C. for 6 hours to obtain a molecular sieve precursor;

[0096] Step 4: The molecular sieve precursor was mixed with ammonium chloride at 70° C. for 4 hours, washed, dried, and calcined at 500° C. for 6 hours to obtain the ZSM-48 molecular sieve, which was designated as molecular sieve A1.

[0097] Example 2

[0098] This embodiment provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0099] Step 1: 0.49 g of sodium aluminate, 18 g of white carbon black, 0.48 g of NaOH, 1.06 g of sodium sulfate, 0.05 g of hexamethylammonium chloride, 5.4 g of 1.8-octanediamine, 81 g of deionized water, 4.7 g of polyhexamethylene biguanide, and 275 g of ethylene glycol were mixed at 60° C. to obtain a gel solution;

[0100] Among them, the aluminum source in terms of Al2O3, - The molar ratio of the alkali source, template, H2O and silicon source calculated as SiO2 is 0.02:0.04:0.12:15:1;

[0101] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.07:1;

[0102] The molar ratio of the crystallization inducer calculated as Na2O to the silicon source calculated as SiO2 is 0.02:1;

[0103] The molar ratio of charge balancer to H2O is 0.98:1;

[0104] The molar ratio of the first template to the second template is 204:1;

[0105] Step 2: pre-crystallizing the gel solution at 90° C. for 6 h, crystallizing at 140° C. for 6 h, and crystallizing at 170° C. for 10 h to obtain a crystallized product;

[0106] Step 3: washing, drying and calcining the crystallized product at 600° C. for 30 hours to obtain a molecular sieve precursor;

[0107] Step 4: The molecular sieve precursor was mixed with ammonium chloride at 80° C. for 6 hours, washed, dried, and calcined at 600° C. for 30 hours to obtain a ZSM-48 molecular sieve, which was designated as molecular sieve A2.

[0108] Example 3

[0109] This embodiment provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0110] Step 1: 0.32 g aluminum nitrate, 18 g ethyl orthosilicate, 1 g KOH, 2.58 g KCl, 0.2 g ammonium oxalate, 16 g 1,6-hexanediamine, 62.3 g deionized water, 5.1 g Triton X-100, and 100 g isopropyl alcohol were mixed at 45° C. to obtain a gel solution;

[0111] Among them, the aluminum source in terms of Al2O3, - The molar ratio of the alkali source, template, H2O and silicon source calculated as SiO2 is 0.01:0.2:1.5:40:1;

[0112] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.2:1;

[0113] The molar ratio of the crystallization inducer calculated as K2O to the silicon source calculated as SiO2 is 0.2:1;

[0114] The molar ratio of charge balancer to H2O is 0.48:1;

[0115] The molar ratio of the first template to the second template is 85:1;

[0116] Step 2: pre-crystallizing the gel solution at 80° C. for 4 h, crystallizing at 130° C. for 4 h, and crystallizing at 160° C. for 20 h to obtain a crystallized product;

[0117] Step 3: Washing, drying and calcining the crystallized product at 550° C. for 20 hours to obtain a molecular sieve precursor;

[0118] Step 4: The molecular sieve precursor was mixed with ammonium chloride at 75° C. for 4 hours, washed, dried, and calcined at 530° C. for 24 hours to obtain the ZSM-48 molecular sieve, which was designated as molecular sieve A3.

[0119] Example 4

[0120] This embodiment provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0121] Step 1: 0.12 g aluminum nitrate, 18 g silica sol (40 wt% solid content), 1.86 g NaOH, 0.43 g potassium sulfate, 0.1 g benzyltriethylammonium bromide, 10 g benzylamine, 100 g deionized water, 7.2 g P123, and 46 g 2-butanol were mixed at 50° C. to obtain a gel solution;

[0122] Among them, the aluminum source in terms of Al2O3, - The molar ratio of the alkali source, template, H2O and silicon source calculated as SiO2 is 0.0026:0.38:0.76:50:1;

[0123] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.01:1;

[0124] The molar ratio of the crystallization inducer calculated as K2O to the silicon source calculated as SiO2 is 0.02:1;

[0125] The molar ratio of charge balancer to H2O was 0.1:1;

[0126] The molar ratio of the first template to the second template is 254:1;

[0127] Step 2: pre-crystallizing the gel solution at 85°C for 5 hours, crystallizing at 135°C for 5 hours, and crystallizing at 160°C for 30 hours to obtain a crystallized product;

[0128] Step 3: Washing, drying and calcining the crystallized product at 530° C. for 12 hours to obtain a molecular sieve precursor;

[0129] Step 4: The molecular sieve precursor was mixed with ammonium nitrate at 70° C. for 4 hours, washed, dried, and calcined at 560° C. for 28 hours to obtain the ZSM-48 molecular sieve, which was designated as molecular sieve A4.

[0130] Example 5

[0131] This embodiment provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0132] Step 1: Mix 0.15 g of aluminum nitrate nonahydrate, 18 g of silica sol (solid content 40%), 1.2 g of NaOH, 0.5 g of K2SO4, 10 g of dodecylamine, 0.1 g of ammonium acetate, 80 g of deionized water, 0.2 g of ammonium chloride, and 50 g of propanol at 43°C to obtain a gel solution.

[0133] Among them, the aluminum source in terms of Al2O3, - The molar ratio of the alkali source, template, H2O and silicon source calculated as SiO2 is 0.0033:0.25:0.46:42.1:1;

[0134] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.03:1;

[0135] The molar ratio of the crystallization inducer calculated as K2O to the silicon source calculated as SiO2 is 0.024:1;

[0136] The molar ratio of charge balancer to H2O is 0.165:1;

[0137] The molar ratio of the first template to the second template is 41.59:1;

[0138] Step 2: pre-crystallizing the gel solution at 80° C. for 4 h, crystallizing at 130° C. for 4 h, and crystallizing at 160° C. for 20 h to obtain a crystallized product;

[0139] Step 3: Washing, drying and calcining the crystallized product at 550° C. for 20 hours to obtain a molecular sieve precursor;

[0140] Step 4: The molecular sieve precursor was mixed with ammonium sulfate at 75° C. for 4 hours, washed, dried, and calcined at 530° C. for 24 hours to obtain the ZSM-48 molecular sieve, which was designated as molecular sieve A5.

[0141] Example 6

[0142] This embodiment provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0143] Step 1: Mix 0.15 g of aluminum nitrate nonahydrate, 18 g of silica sol (solid content 40%), 1.2 g of NaOH, 0.5 g of K2SO4, 10 g of dodecylamine, 80 g of deionized water, 0.2 g of ammonium chloride, and 50 g of propanol at 43°C to obtain a gel solution.

[0144] The molar ratio of the aluminum source calculated as Al2O3, the alkali source calculated as OH-, the template, H2O and the silicon source calculated as SiO2 is 0.0033:0.25:0.46:42.1:1;

[0145] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.03:1;

[0146] The molar ratio of the crystallization inducer calculated as K2O to the silicon source calculated as SiO2 is 0.024:1;

[0147] The molar ratio of charge balancer to H2O is 0.165:1;

[0148] Step 2: pre-crystallizing the gel solution at 80° C. for 4 h, crystallizing at 130° C. for 4 h, and crystallizing at 160° C. for 20 h to obtain a crystallized product;

[0149] Step 3: Washing, drying and calcining the crystallized product at 550° C. for 20 hours to obtain a molecular sieve precursor;

[0150] Step 4: The molecular sieve precursor was mixed with ammonium sulfate at 75° C. for 4 hours, washed, dried, and calcined at 530° C. for 24 hours to obtain the ZSM-48 molecular sieve, which was designated as molecular sieve A6.

[0151] Comparative Example 1

[0152] This comparative example provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0153] Step 1: 0.32 g aluminum nitrate, 18 g ethyl orthosilicate, 1 g KOH, 0.2 g ammonium oxalate, 16 g 1,6-hexanediamine, 62.3 g deionized water, 5.1 g Triton X-100, and 100 g isopropyl alcohol were mixed at 45° C. to obtain a gel solution;

[0154] Among them, the aluminum source in terms of Al2O3, - The molar ratio of the alkali source, template, H2O and silicon source calculated as SiO2 is 0.01:0.2:1.5:40:1;

[0155] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.2:1;

[0156] The molar ratio of charge balancer to H2O is 0.48:1;

[0157] The molar ratio of the first template to the second template is 85:1;

[0158] Step 2: pre-crystallizing the gel solution at 80° C. for 4 h, crystallizing at 130° C. for 4 h, and crystallizing at 160° C. for 20 h to obtain a crystallized product;

[0159] Step 3: washing, drying and calcining the crystallized product at 550° C. for 20 hours to obtain a molecular sieve precursor;

[0160] Step 4: The molecular sieve precursor was mixed with ammonium chloride at 75° C. for 4 hours, washed, dried, and calcined at 530° C. for 24 hours to obtain the ZSM-48 molecular sieve, which was designated as molecular sieve A7.

[0161] Comparative Example 2

[0162] This comparative example provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0163] Step 1: 0.32 g aluminum nitrate, 18 g ethyl orthosilicate, 1 g KOH, 1.3 g KCl, 0.2 g ammonium oxalate, 16 g 1,6-hexanediamine, and 62.3 g deionized water were mixed at 45° C. to obtain a gel solution;

[0164] Among them, the aluminum source in terms of Al2O3, - The molar ratio of the alkali source, template, H2O and silicon source calculated as SiO2 is 0.01:0.2:1.5:40:1;

[0165] The molar ratio of the crystallization inducer calculated as K2O to the silicon source calculated as SiO2 is 0.1:1;

[0166] The molar ratio of the first template to the second template is 85:1;

[0167] Step 2: pre-crystallizing the gel solution at 80° C. for 4 h, crystallizing at 130° C. for 4 h, and crystallizing at 160° C. for 20 h to obtain a crystallized product;

[0168] Step 3: washing, drying and calcining the crystallized product at 550° C. for 20 hours to obtain a molecular sieve precursor;

[0169] Step 4: The molecular sieve precursor was mixed with ammonium chloride at 75° C. for 4 hours, washed, dried, and calcined at 530° C. for 24 hours to obtain the ZSM-48 molecular sieve, which was designated as molecular sieve A8.

[0170] Comparative Example 3

[0171] This comparative example provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0172] Step 1: 0.32 g aluminum nitrate, 18 g ethyl orthosilicate, 1 g KOH, 1.3 g KCl, 0.2 g ammonium oxalate, 16 g 1,6-hexanediamine, 5.1 g Triton X-100, and 62.3 g deionized water were mixed at 45° C. to obtain a gel solution;

[0173] Among them, the aluminum source in terms of Al2O3, - The molar ratio of the alkali source, template, H2O and silicon source calculated as SiO2 is 0.01:0.2:1.5:40:1;

[0174] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.2:1;

[0175] The molar ratio of the crystallization inducer calculated as K2O to the silicon source calculated as SiO2 is 0.1:1;

[0176] The molar ratio of the first template to the second template is 85:1;

[0177] Step 2: pre-crystallizing the gel solution at 80° C. for 4 h, crystallizing at 130° C. for 4 h, and crystallizing at 160° C. for 20 h to obtain a crystallized product;

[0178] Step 3: washing, drying and calcining the crystallized product at 550° C. for 20 hours to obtain a molecular sieve precursor;

[0179] Step 4: The molecular sieve precursor was mixed with ammonium chloride at 75° C. for 4 hours, washed, dried, and calcined at 530° C. for 24 hours to obtain the ZSM-48 molecular sieve, which was designated as molecular sieve A9.

[0180] Comparative Example 4

[0181] This comparative example provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0182] Step 1: 0.32 g aluminum nitrate, 18 g ethyl orthosilicate, 1 g KOH, 1.3 g KCl, 0.2 g ammonium oxalate, 16 g 1,6-hexanediamine, 62.3 g deionized water, 5.1 g Triton X-100, and 100 g isopropyl alcohol were mixed at 45° C. to obtain a gel solution;

[0183] Among them, the aluminum source in terms of Al2O3, - The molar ratio of the alkali source, template, H2O and silicon source calculated as SiO2 is 0.01:0.2:1.5:40:1;

[0184] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.2:1;

[0185] The molar ratio of the crystallization inducer calculated as K2O to the silicon source calculated as SiO2 is 0.1:1;

[0186] The molar ratio of charge balancer to H2O is 0.48:1;

[0187] The molar ratio of the first template to the second template is 85:1;

[0188] Step 2: crystallizing the gel solution at 160° C. for 28 h to obtain a crystallized product;

[0189] Step 3: washing, drying and calcining the crystallized product at 550° C. for 20 hours to obtain a molecular sieve precursor;

[0190] Step 4: The molecular sieve precursor was mixed with ammonium chloride at 75° C. for 4 hours, washed, dried, and calcined at 530° C. for 24 hours to obtain the ZSM-48 molecular sieve, which was designated as molecular sieve A10.

[0191] Comparative Example 5

[0192] This embodiment provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0193] Step 1: 3.22 g of aluminum sulfate, 36 g of silica sol (40 wt% solid content), 0.06 g of NaOH, 0.06 g of NaCl, 4.7 g of hexamethonium bromide, 1.4 g of cyclohexylamine, 24 g of deionized water, 0.74 g of Triton X-100, and 48 g of bis(cyclopentadienyl)cobalt were mixed at 40° C. to obtain a gel solution;

[0194] Among them, the aluminum source in terms of Al2O3, - The molar ratio of the alkali source, template, H2O and silicon source calculated as SiO2 is 0.02:0.006:0.11:10:1;

[0195] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.01:1;

[0196] The molar ratio of the crystallization inducer calculated as Na2O to the silicon source calculated as SiO2 is 0.002:1;

[0197] The molar ratio of charge balancer to H2O was 0.1:1;

[0198] The molar ratio of cyclohexylamine to hexamethylammonium bromide is 1:1;

[0199] Step 2: pre-crystallizing the gel solution at 70° C. for 2 h, crystallizing at 120° C. for 2 h, and crystallizing at 140° C. for 48 h to obtain a crystallized product;

[0200] Step 3: washing, drying and calcining the crystallized product at 500° C. for 6 hours to obtain a molecular sieve precursor;

[0201] Step 4: The molecular sieve precursor is mixed with ammonium chloride at 70° C. for 4 hours, washed, dried and calcined at 500° C. for 6 hours to obtain the ZSM-48 molecular sieve, which also contains ZSM-5 impurities and amorphous silica-alumina, and is recorded as molecular sieve A11.

[0202] Comparative Example 6

[0203] This embodiment provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0204] Step 1: 3.22 g of aluminum sulfate, 36 g of silica sol (40 wt% solid content), 0.06 g of NaOH, 0.06 g of NaCl, 4.7 g of hexamethonium bromide, 1.4 g of cyclohexylamine, 24 g of deionized water, 0.74 g of Triton X-100, and 29.3 g of 1,6-hexanediamine were mixed at 40° C. to obtain a gel solution;

[0205] Among them, the aluminum source in terms of Al2O3, - The molar ratio of the alkali source, template, H2O and silicon source calculated as SiO2 is 0.02:0.006:0.11:10:1;

[0206] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.01:1;

[0207] The molar ratio of the crystallization inducer calculated as Na2O to the silicon source calculated as SiO2 is 0.002:1;

[0208] The molar ratio of charge balancer to H2O was 0.1:1;

[0209] The molar ratio of cyclohexylamine to hexamethylammonium bromide is 1:1;

[0210] Step 2: pre-crystallizing the gel solution at 70° C. for 2 h, crystallizing at 120° C. for 2 h, and crystallizing at 140° C. for 48 h to obtain a crystallized product;

[0211] Step 3: washing, drying and calcining the crystallized product at 500° C. for 6 hours to obtain a molecular sieve precursor;

[0212] Step 4: The molecular sieve precursor is mixed with ammonium chloride at 70° C. for 4 hours, washed, dried and calcined at 500° C. for 6 hours to obtain the ZSM-48 molecular sieve containing ZSM-5 impurities and amorphous silica-alumina, which is recorded as molecular sieve A12.

[0213] Comparative Example 7

[0214] This embodiment provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0215] Step 1: 3.22 g of aluminum sulfate, 36 g of silica sol (40 wt% solid content), 0.06 g of NaOH, 0.06 g of NaCl, 4.7 g of hexamethonium bromide, 1.4 g of cyclohexylamine, 24 g of deionized water, 0.74 g of Triton X-100, and 2.5 g of glycerol were mixed at 40° C. to obtain a gel solution;

[0216] The molar ratio of the aluminum source calculated as Al2O3, the alkali source calculated as OH-, the template, H2O and the silicon source calculated as SiO2 is 0.02:0.006:0.11:10:1;

[0217] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.01:1;

[0218] The molar ratio of the crystallization inducer calculated as Na2O to the silicon source calculated as SiO2 is 0.002:1;

[0219] The molar ratio of charge balancer to H2O was 0.01:1;

[0220] The molar ratio of cyclohexylamine to hexamethylammonium bromide is 1:1;

[0221] Step 2: pre-crystallizing the gel solution at 70° C. for 2 h, crystallizing at 120° C. for 2 h, and crystallizing at 140° C. for 48 h to obtain a crystallized product;

[0222] Step 3: washing, drying and calcining the crystallized product at 500° C. for 6 hours to obtain a molecular sieve precursor;

[0223] Step 4: The molecular sieve precursor is mixed with ammonium chloride at 70° C. for 4 hours, washed, dried and calcined at 500° C. for 6 hours to obtain the ZSM-48 molecular sieve containing ZSM-5 impurities and amorphous silica-alumina, which is recorded as molecular sieve A13.

[0224] Comparative Example 8

[0225] This embodiment provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0226] Step 1: 3.22 g of aluminum sulfate, 36 g of silica sol (40 wt% solid content), 0.06 g of NaOH, 0.06 g of NaCl, 4.7 g of hexamethonium bromide, 1.4 g of cyclohexylamine, 24 g of deionized water, 0.74 g of Triton X-100, and 465 g of glycerol were mixed at 40° C. to obtain a gel solution;

[0227] The molar ratio of the aluminum source calculated as Al2O3, the alkali source calculated as OH-, the template, H2O and the silicon source calculated as SiO2 is 0.02:0.006:0.11:10:1;

[0228] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.01:1;

[0229] The molar ratio of the crystallization inducer calculated as Na2O to the silicon source calculated as SiO2 is 0.002:1;

[0230] The molar ratio of charge balancer to H2O is 2:1;

[0231] The molar ratio of cyclohexylamine to hexamethylammonium bromide is 1:1;

[0232] Step 2: pre-crystallizing the gel solution at 70° C. for 2 h, crystallizing at 120° C. for 2 h, and crystallizing at 140° C. for 48 h to obtain a crystallized product;

[0233] Step 3: washing, drying and calcining the crystallized product at 500° C. for 6 hours to obtain a molecular sieve precursor;

[0234] Step 4: The molecular sieve precursor was mixed with ammonium chloride at 70° C. for 4 hours, washed, dried and calcined at 500° C. for 6 hours to obtain the ZSM-5 molecular sieve and amorphous silica-alumina, which was designated as molecular sieve A14.

[0235] The total BET specific surface area, micropore specific surface area and mesopore specific surface area data of molecular sieves A1 to molecular sieve A14 provided by Examples 1 to 6 and Comparative Examples 1 to 8 of the present invention are shown in Table 1 below, respectively.

[0236] Table 1

[0237] As can be seen from Table 1 above, the molecular sieves A1 to A14 provided in Examples 1 to 6 of the present invention and Comparative Examples 1 to 8 all have micropores and mesopores, but the total BET specific surface area and mesopore specific surface area of ​​the molecular sieves prepared in the comparative examples are significantly lower than those provided in the embodiments of the present invention.

[0238] The XRD pattern and SEM pattern of the molecular sieve A1 provided in Example 1 of the present invention are shown in Figures 1 and 2, respectively. The XRD pattern and SEM pattern of the molecular sieve A7 provided in Comparative Example 1 are shown in Figures 3 and 4, respectively. The XRD pattern and SEM pattern of the molecular sieve A9 provided in Comparative Example 3 are shown in Figures 5 and 6, respectively. The XRD pattern of the molecular sieve A11 provided in Comparative Example 5 is shown in Figure 7, and the XRD pattern of the molecular sieve A12 provided in Comparative Example 6 is shown in Figure 8. As can be seen from Figures 1, 3 and 5, molecular sieves A1, A7 and A9 are all pure phase ZSM-48 molecular sieves without impurity crystal formation. However, as can be seen from Figure 2, the crystal length of molecular sieve A1 is 100-500nm, the crystal diameter is 50-100nm, and the axis-diameter ratio is about 2-10, indicating that it is a short-axis ZSM-molecular sieve. Comparison of Figures 2, 4 and 6 and the experimental data in Table 1 shows that compared with the molecular sieve A1 provided in Example 1, the molecular sieves A7-molecular sieve A12 provided in Comparative Examples 1-6 have larger grain sizes and axis-diameter ratios. As can be seen from Figures 7 and 8, Comparative Examples 5 and 6 respectively add non-alcohol charge balancers such as organometallic complexes (bis(cyclopentadiene)cobalt) and organic amines (1,6-hexanediamine) to prepare molecular sieves. These non-alcohol charge balancers will affect the pH value or structural orientation of the system, and are prone to produce miscellaneous crystals or amorphous forms.

[0239] In addition, compared to Example 5, Example 6 only uses dodecylamine as a template, and does not use ammonium acetate as a template. As can be seen from Table 1 above, compared to A5, A6 has a smaller specific surface area and larger crystals, which is prone to producing miscellaneous crystals or amorphous structures.

[0240] The molar ratio of the charge-balancer to HO in Comparative Example 7 was 0.01:1, and the molar ratio of the charge-balancer to HO in Comparative Example 8 was 2:1, both of which are outside the scope of protection claimed in this application. As can be seen from Table 1 above, compared to A1, A13 and A14 have smaller specific surface areas and larger crystallites, which are prone to producing miscellaneous crystals or amorphous structures.

[0241] In summary, by comparing the molecular sieve A1 provided in Example 1 and the molecular sieves A11 to A12 provided in Comparative Examples 5 and 6, it can be seen that compared with the bis(cyclopentadiene)cobalt and 1,6-hexanediamine charge balancers used in Comparative Examples 5 and 6, the use of alcohol charge balancers such as propylene glycol in Example 1 of the present invention can obtain a pure phase molecular sieve, and the parameters such as the grain size and axial diameter ratio of the molecular sieve are smaller.

[0242] Isodewaxing Catalyst Examples and Comparative Examples

[0243] Example 7

[0244] This embodiment provides an isodewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0245] Step (1): 100 g of molecular sieve A1, 30 g of pseudo-boehmite, 1 g of titanium dioxide, 1 g of nitric acid solution (5 wt%), 30 g of sesbania powder, and 20 g of deionized water were mixed uniformly, extruded, dried, and calcined at 400° C. for 6 hours to obtain carrier particles;

[0246] The mass ratio of each component is: molecular sieve A1: alumina: titanium dioxide: acid solution: binder: deionized water = 1:0.3:0.01:0.01:0.3:0.2;

[0247] Step (2): dissolving 1.32 g of chloroplatinic acid hexahydrate in a mixture of 25 g of water, 25 g of ethanol, and 1.74 g of sorbic acid ligand, and mixing at 30° C. for 2 h to obtain a noble metal precursor solution with a molar ratio of sorbic acid to platinum atoms of 6:1;

[0248] Step (3): 100 g of carrier particles were immersed in the precious metal precursor solution for 2 h, dried at 100 ° C for 2 h, and then calcined at 400 ° C for 6 h in an air atmosphere to obtain an isodewaxing catalyst with a precious metal loading of 0.5 wt%, recorded as catalyst C1.

[0249] Example 8

[0250] This embodiment provides an isodewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0251] Step (1): 10 g of molecular sieve A2, 90 g of pseudo-boehmite, 5 g of titanium dioxide, 6 g of phosphoric acid solution (15 wt%), 10 g of methyl cellulose, and 10 g of deionized water were mixed uniformly, extruded, dried, and calcined at 500° C. for 14 hours to obtain carrier particles;

[0252] The mass ratio of each component is: molecular sieve A2: alumina: titanium dioxide: acid solution: binder: deionized water = 1:9:0.5:0.6:1:1;

[0253] Step (2): dissolving 0.18 g of palladium chloride in 50 g of water, 1 g of propanol, and 2.53 g of a salicylic acid ligand mixture, and mixing at 60° C. for 4 h to obtain a noble metal precursor solution, wherein the molar ratio of salicylic acid to palladium atoms is 18:1;

[0254] Step (3): Immerse 100 g of carrier particles in the precious metal precursor solution for 4 h, dry them at 120 ° C for 2 h, and then calcine them at 500 ° C for 14 h in an air atmosphere to obtain an isodewaxing catalyst with a precious metal loading of 0.5 wt%, recorded as catalyst C2.

[0255] Example 9

[0256] This embodiment provides an isodewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0257] Step (1): 20 g of molecular sieve A3, 100 g of pseudo-boehmite, 4 g of titanium dioxide, 6 g of nitric acid solution (5 wt%), 10 g of sesbania powder, and 16 g of deionized water were mixed uniformly, extruded, dried, and calcined at 450° C. for 10 hours to obtain carrier particles;

[0258] The mass ratio of each component is: molecular sieve: alumina: titanium dioxide: acid solution: binder: deionized water = 1:5:0.2:0.3:0.5:0.8;

[0259] Step (2): dissolving 0.42 g of platinum dichloride in 50 g of water, 2 g of isopropanol, and 1.71 g of a lactic acid ligand mixture, and mixing at 30° C. for 2 h to obtain a noble metal precursor solution, wherein the molar ratio of lactic acid to platinum atoms is 12:1;

[0260] Step (3): Immerse 100 g of carrier particles in the precious metal precursor solution for 2 h, dry them at 100 ° C for 2 h, and then calcine them at 450 ° C for 10 h in an air atmosphere to obtain an isodewaxing catalyst with a precious metal loading of 0.3 wt%, recorded as catalyst C3.

[0261] Example 10

[0262] This embodiment provides an isodewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0263] Step (1): 100 g of molecular sieve A4, 50 g of pseudo-boehmite, 5 g of titanium dioxide, 8 g of nitric acid solution (5 wt%), 40 g of sesbania powder, and 30 g of deionized water were mixed uniformly, extruded, dried, and calcined at 480° C. for 12 hours to obtain carrier particles;

[0264] The mass ratio of each component is: molecular sieve: alumina: titanium dioxide: acid solution: binder: deionized water = 1:0.5:0.05:0.08:0.4:0.3;

[0265] Step (2): dissolving 0.46 g of ammonium hexachloroplatinate in a mixture of 40 g of water, 10 g of glycerol, and 1.9 g of a nicotinamide ligand at 30° C. for 2 h to obtain a noble metal precursor solution, wherein the molar ratio of nicotinamide to platinum atoms is 15:1;

[0266] Step (3): Immerse 100 g of carrier particles in the precious metal precursor solution for 2 h. After the immersion, dry them at 100°C for 2 h. Then, calcine them at 480°C in an air atmosphere for 12 h to obtain an isodewaxing catalyst with a precious metal loading of 0.2 wt%, recorded as catalyst C4.

[0267] Example 11

[0268] This embodiment provides an isodewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0269] Step (1): 100 g of molecular sieve A4, 50 g of pseudo-boehmite, 5 g of titanium dioxide, 8 g of nitric acid solution (5 wt%), 40 g of sesbania powder, and 30 g of deionized water were mixed uniformly, extruded, dried, and calcined at 480° C. for 12 hours to obtain carrier particles;

[0270] The mass ratio of each component is: molecular sieve: alumina: titanium dioxide: acid solution: binder: deionized water = 1:0.5:0.05:0.08:0.4:0.3;

[0271] Step (2): dissolving 0.46 g of ammonium hexachloroplatinate in a mixture of 40 g of water, 10 g of glycerol, and 1.98 g of a ligand solution of citric acid monohydrate at 33° C. for 2 h to obtain a noble metal precursor solution, wherein the molar ratio of citric acid monohydrate to platinum atoms is 9.09:1;

[0272] Step (3): Immerse 100 g of carrier particles in the precious metal precursor solution for 2 h. After the immersion, dry them at 100°C for 2 h. Then, calcine them at 600°C for 12 h in an air atmosphere to obtain an isodewaxing catalyst with a precious metal loading of 0.2 wt%, which is recorded as catalyst C5.

[0273] Example 12

[0274] This embodiment provides an isodewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0275] Step (1): 100 g of molecular sieve A4, 50 g of pseudo-boehmite, 5 g of titanium dioxide, 8 g of nitric acid solution (5 wt%), 40 g of sesbania powder, and 30 g of deionized water were mixed uniformly, extruded, dried, and calcined at 480° C. for 12 hours to obtain carrier particles;

[0276] The mass ratio of each component is: molecular sieve: alumina: titanium dioxide: acid solution: binder: deionized water = 1:0.5:0.05:0.08:0.4:0.3;

[0277] Step (2): dissolving 0.46 g of ammonium hexachloroplatinate in a mixture of 40 g of water, 10 g of glycerol, and 26 g of a hyaluronic acid (Mn≈3500) ligand solution at 34° C. for 2 h to obtain a noble metal precursor solution having a molar ratio of nicotinamide to platinum atoms of 7.17:1;

[0278] Step (3): Immerse 100 g of carrier particles in the precious metal precursor solution for 2 h. After the immersion, dry them at 100°C for 2 h. Then, calcine them at 500°C for 12 h in an air atmosphere to obtain an isodewaxing catalyst with a precious metal loading of 0.2 wt%, recorded as catalyst C6.

[0279] Example 13

[0280] This embodiment provides an isodewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0281] Step (1): 100 g of molecular sieve A5, 30 g of pseudo-boehmite, 1 g of titanium dioxide, 1 g of nitric acid solution (5 wt%), 30 g of sesbania powder, and 20 g of deionized water were mixed uniformly, extruded, dried, and calcined at 400° C. for 6 hours to obtain carrier particles;

[0282] The mass ratio of each component is: molecular sieve A5: alumina: titanium dioxide: acid solution: binder: deionized water = 1:0.3:0.01:0.01:0.3:0.2;

[0283] Step (2): dissolving 1.32 g of chloroplatinic acid hexahydrate in a mixture of 25 g of water, 25 g of ethanol, and 1.74 g of sorbic acid ligand, and mixing at 30° C. for 2 h to obtain a noble metal precursor solution with a molar ratio of sorbic acid to platinum atoms of 6:1;

[0284] Step (3): 100 g of carrier particles were immersed in the precious metal precursor solution for 2 h, dried at 100 ° C for 2 h, and then calcined at 400 ° C for 6 h in an air atmosphere to obtain an isodewaxing catalyst with a precious metal loading of 0.5 wt%, recorded as catalyst C7.

[0285] Example 14

[0286] This embodiment provides an isodewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0287] Step (1): 100 g of molecular sieve A6, 30 g of pseudo-boehmite, 1 g of titanium dioxide, 1 g of nitric acid solution (5 wt%), 30 g of sesbania powder, and 20 g of deionized water were mixed uniformly, extruded, dried, and calcined at 400° C. for 6 hours to obtain carrier particles;

[0288] The mass ratio of each component is: molecular sieve A6: alumina: titanium dioxide: acid solution: binder: deionized water = 1:0.3:0.01:0.01:0.3:0.2;

[0289] Step (2): dissolving 1.32 g of chloroplatinic acid hexahydrate in a mixture of 25 g of water, 25 g of ethanol, and 1.74 g of sorbic acid ligand, and mixing at 30° C. for 2 h to obtain a noble metal precursor solution with a molar ratio of sorbic acid to platinum atoms of 6:1;

[0290] Step (3): Immerse 100 g of carrier particles in the precious metal precursor solution for 2 h, dry them at 100 ° C for 2 h, and then calcine them at 400 ° C for 6 h in an air atmosphere to obtain an isodewaxing catalyst with a precious metal loading of 0.5 wt%, recorded as catalyst C8.

[0291] Comparative Example 9

[0292] This comparative example provides an isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0293] Step (1): 20 g of molecular sieve A7, 100 g of pseudo-boehmite, 4 g of titanium dioxide, 6 g of nitric acid solution (5 wt%), 10 g of sesbania powder, and 16 g of deionized water were mixed uniformly, extruded, dried, and calcined at 450° C. for 10 hours to obtain carrier particles;

[0294] The mass ratio of each component is: molecular sieve A7: alumina: titanium dioxide: acid solution: binder: deionized water = 1:5:0.2:0.3:0.5:0.8;

[0295] Step (2): dissolving 0.42 g of platinum dichloride in 50 g of water, 2 g of isopropanol, and 1.71 g of a lactic acid ligand mixture, and mixing at 30° C. for 2 h to obtain a noble metal precursor solution, wherein the molar ratio of lactic acid to platinum atoms is 12:1;

[0296] Step (3): Immerse 100 g of carrier particles in the precious metal precursor solution for 2 h. After the immersion, dry them at 100 ° C for 2 h. Then, calcine them at 450 ° C for 10 h in an air atmosphere to obtain an isodewaxing catalyst with a precious metal loading of 0.3 wt%, recorded as catalyst C9.

[0297] Comparative Example 10

[0298] This comparative example provides an isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0299] Step (1): 20 g of molecular sieve A8, 100 g of pseudo-boehmite, 4 g of titanium dioxide, 6 g of nitric acid solution (5 wt%), 10 g of sesbania powder, and 16 g of deionized water were mixed uniformly, extruded, dried, and calcined at 450° C. for 10 hours to obtain carrier particles;

[0300] The mass ratio of each component is: molecular sieve A8: alumina: titanium dioxide: acid solution: binder: deionized water = 1:5:0.2:0.3:0.5:0.8;

[0301] Step (2): dissolving 0.42 g of platinum dichloride in 50 g of water, 2 g of isopropanol, and 1.71 g of a lactic acid ligand mixture, and mixing at 30° C. for 2 h to obtain a noble metal precursor solution, wherein the molar ratio of lactic acid to platinum atoms is 12:1;

[0302] Step (3): Immerse 100 g of carrier particles in the precious metal precursor solution for 2 h, dry them at 100 ° C for 2 h, and then calcine them at 450 ° C for 10 h in an air atmosphere to obtain an isodewaxing catalyst with a precious metal loading of 0.3 wt%, recorded as catalyst C10.

[0303] Comparative Example 11

[0304] This comparative example provides an isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0305] Step (1): 20 g of molecular sieve A9, 100 g of pseudo-boehmite, 4 g of titanium dioxide, 6 g of nitric acid solution (5 wt%), 10 g of sesbania powder, and 16 g of deionized water were mixed uniformly, extruded, dried, and calcined at 450° C. for 10 hours to obtain carrier particles;

[0306] The mass ratio of each component is: molecular sieve A9: alumina: titanium dioxide: acid solution: binder: deionized water = 1:5:0.2:0.3:0.5:0.8;

[0307] Step (2): dissolving 0.42 g of platinum dichloride in 50 g of water, 2 g of isopropanol, and 1.71 g of a lactic acid ligand mixture, and mixing at 30° C. for 2 h to obtain a noble metal precursor solution, wherein the molar ratio of lactic acid to platinum atoms is 12:1;

[0308] Step (3): Immerse 100 g of carrier particles in the precious metal precursor solution for 2 h, dry them at 100 ° C for 2 h, and then calcine them at 450 ° C for 10 h in an air atmosphere to obtain an isodewaxing catalyst with a precious metal loading of 0.3 wt%, recorded as catalyst C11.

[0309] Comparative Example 12

[0310] This comparative example provides an isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0311] Step (1): 100 g of molecular sieve A3, 20 g of pseudo-boehmite, 4 g of titanium dioxide, 6 g of nitric acid solution (5 wt%), 10 g of sesbania powder, and 16 g of deionized water were mixed uniformly, extruded, dried, and calcined at 450° C. for 10 hours to obtain carrier particles;

[0312] The mass ratio of each component is: molecular sieve A3: alumina: titanium dioxide: acid solution: binder: deionized water = 1:0.2:0.04:0.06:0.1:0.16;

[0313] Step (2): dissolving 0.42 g of platinum dichloride in 50 g of water, 2 g of isopropanol, and 1.71 g of a lactic acid ligand mixture, and mixing at 30° C. for 2 h to obtain a noble metal precursor solution, wherein the molar ratio of lactic acid to platinum atoms is 12:1;

[0314] Step (3): Immerse 100 g of carrier particles in the precious metal precursor solution for 2 h, dry them at 100 ° C for 2 h, and then calcine them at 450 ° C for 10 h in an air atmosphere to obtain an isodewaxing catalyst with a precious metal loading of 0.3 wt%, recorded as catalyst C12.

[0315] Comparative Example 13

[0316] This comparative example provides an isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0317] Step (1): 100 g of molecular sieve A11, 30 g of pseudo-boehmite, 1 g of titanium dioxide, 1 g of nitric acid solution (5 wt%), 30 g of sesbania powder, and 20 g of deionized water were mixed uniformly, extruded, dried, and calcined at 400° C. for 6 hours to obtain carrier particles;

[0318] The mass ratio of each component is: molecular sieve A11: alumina: titanium dioxide: acid solution: binder: deionized water = 1:0.3:0.01:0.01:0.3:0.2;

[0319] Step (2): dissolving 1.32 g of chloroplatinic acid hexahydrate in a mixture of 25 g of water, 25 g of ethanol, and 1.74 g of sorbic acid ligand, and mixing at 30° C. for 2 h to obtain a noble metal precursor solution with a molar ratio of sorbic acid to platinum atoms of 6:1;

[0320] Step (3): Immerse 100 g of carrier particles in the precious metal precursor solution for 2 h, dry them at 100 ° C for 2 h, and then calcine them at 400 ° C for 6 h in an air atmosphere to obtain an isodewaxing catalyst with a precious metal loading of 0.5 wt%, recorded as catalyst C13.

[0321] Comparative Example 14

[0322] This comparative example provides an isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0323] Step (1): 100 g of molecular sieve A13, 30 g of pseudo-boehmite, 1 g of titanium dioxide, 1 g of nitric acid solution (5 wt%), 30 g of sesbania powder, and 20 g of deionized water were mixed uniformly, extruded, dried, and calcined at 400° C. for 6 hours to obtain carrier particles;

[0324] The mass ratio of each component is: molecular sieve A13: alumina: titanium dioxide: acid solution: binder: deionized water = 1:0.3:0.01:0.01:0.3:0.2;

[0325] Step (2): dissolving 1.32 g of chloroplatinic acid hexahydrate in a mixture of 25 g of water, 25 g of ethanol, and 1.74 g of sorbic acid ligand, and mixing at 30° C. for 2 h to obtain a noble metal precursor solution with a molar ratio of sorbic acid to platinum atoms of 6:1;

[0326] Step (3): 100 g of carrier particles were immersed in the noble metal precursor solution for 2 h, dried at 100° C. for 2 h, and then calcined at 400° C. for 6 h in air to obtain an isodewaxing catalyst with a noble metal loading of 0.5 wt %, denoted as catalyst C14.

[0327] Comparative Example 15

[0328] This embodiment provides an isodewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0329] Step (1): 100 g of molecular sieve A14, 30 g of pseudo-boehmite, 1 g of titanium dioxide, 1 g of nitric acid solution (5 wt%), 30 g of sesbania powder, and 20 g of deionized water were mixed uniformly, extruded, dried, and calcined at 400° C. for 6 hours to obtain carrier particles;

[0330] The mass ratio of each component is: molecular sieve A14: alumina: titanium dioxide: acid solution: binder: deionized water = 1:0.3:0.01:0.01:0.3:0.2;

[0331] Step (2): dissolving 1.32 g of chloroplatinic acid hexahydrate in a mixture of 25 g of water, 25 g of ethanol, and 1.74 g of sorbic acid ligand, and mixing at 30° C. for 2 h to obtain a noble metal precursor solution with a molar ratio of sorbic acid to platinum atoms of 6:1;

[0332] Step (3): Immerse 100 g of carrier particles in the precious metal precursor solution for 2 h, dry them at 100 ° C for 2 h, and then calcine them at 400 ° C for 6 h in an air atmosphere to obtain an isodewaxing catalyst with a precious metal loading of 0.5 wt%, recorded as catalyst C15.

[0333] The acidity data of catalysts C1 to C15 provided in Examples 7 to 14 of the present invention and Comparative Examples 9 to 15 are shown in Table 2 below.

[0334] Table 2

[0335] As can be seen from Table 2, the contents of weak Br acid (200°C) and medium-strong Br acid (350°C) in the isomerization dewaxing catalysts provided in Examples 7 to 14 of the present invention are significantly higher than those in the isomerization dewaxing catalysts provided in Comparative Examples 9 to 11 and Comparative Examples 13 to 15. When these isomerization dewaxing catalysts are used for hydroisomerization to prepare lubricating oil, the reaction efficiency can be significantly improved. For C13 in Comparative Example 13, since the molecular sieve A11 used therein contains ZSM-5 miscellaneous crystals and amorphous silica-alumina, the contents of weak Br acid (200°C) and medium-strong Br acid (350°C) in C13 are lower than those in C1-C6. Comparing the data of C1-C6 and C12, it can be seen that although the contents of weak Br acid (200℃) and medium-strong Br acid (350℃) in C12 are roughly equivalent to those in C1-C6, the higher molecular sieve content in C12 makes it more acidic. When it is used for hydroisomerization to prepare lubricating oil, the cracking reaction is more intense, making it unsuitable for isomerization reaction applications, and the catalyst cost is significantly increased.

[0336] C7 and C8 contain A5 and A6, respectively. As shown in Table 1 above, compared to A5, the use of only dodecylamine as a template in the preparation of A6, without ammonium acetate, results in a smaller specific surface area and larger crystals, making it more susceptible to the formation of impurities or amorphous structures. This is reflected in the isodewaxing catalyst, as shown in Table 2 above. Compared to C7 containing A5, C8 containing A6 has lower levels of weak Brønsted acid (200°C) and medium-strong Brønsted acid (350°C). When C7 and C8 are used in hydroisomerization to produce lubricating oils, C7 exhibits superior reaction efficiency to C8 under the same conditions. Verification data is shown in Table 4 below.

[0337] In addition, C1, C14, and C15 contain A1, A13, and A14, respectively, and as shown in Table 1 above, the molar ratio of the charge balancer to H2O in Comparative Example 7 when preparing A13 is 0.01:1, and the molar ratio of the charge balancer to H2O in Comparative Example 8 when preparing A14 is 2:1, both of which are not within the scope of protection claimed in this application. As a result, compared with A1, A13 and A14 have smaller specific surface areas and larger crystallites, which are prone to producing impurity crystals or amorphous forms. This is reflected in the isomerization dewaxing catalyst. As shown in Table 2 above, compared with C1 containing A1, the weak B acid (200°C) and medium-strong B acid (350°C) contents of C14 containing A13 and C15 containing A14 are significantly reduced. When C1, C14, and C15 are used for hydroisomerization to prepare lubricating oil, under the same conditions, the reaction efficiency of C1 is significantly better than that of C14 and C15. The verification data is shown in Table 4 below.

[0338] Catalyst Performance Evaluation Example

[0339] This evaluation example uses hydrocracking tail oil as raw material, with a reaction temperature of 340°C, a reaction pressure of 16 MPa, a hydrogen-to-oil ratio of 500:1, and a volume space velocity of 1.5 h -1 Under the reaction conditions, the microreactor performance of C1-C15 was evaluated. Among them, the parameters of the hydrocracking tail oil feedstock are shown in Table 3 below.

[0340] Table 3

[0341] The evaluation results obtained in this evaluation example are shown in Table 4 below.

[0342] Table 4

[0343] As can be seen from Table 4 above, the liquid yield, lubricating oil yield and heavy viscosity index of the isodewaxing catalysts provided by Examples 7 to 14 of the present invention are significantly higher than those of the isodewaxing catalysts provided by Comparative Examples 9 to 15, while the heavy base oil pour point and heavy base oil cloud point are significantly lower than those of the isodewaxing catalysts provided by Comparative Examples 9 to 15, indicating that the isodewaxing catalysts provided by the embodiments of the present invention have higher reaction efficiency and isomerization conversion rate, as well as lower cracking rate.

[0344] In summary, compared with the prior art, the embodiments of the present invention can achieve the following beneficial technical effects:

[0345] 1) In the examples of the present invention, a crystallization inducer is used in the preparation of the ZSM-48 molecular sieve. This induces the rapid formation of more crystal nuclei, significantly shortens the crystallization time, and reduces the grain size, i.e., forms more small-grain molecular sieves, with a grain length of only 0.1-0.5 μm. When the isomerization dewaxing catalyst (whose carrier particles include the aforementioned ZSM-48 molecular sieve) is used in the hydroisomerization preparation of lubricating oil, the product is facilitated to diffuse out of the pores, thereby reducing the occurrence of cracking reactions.

[0346] 2) In the embodiment of the present invention, alcohols are used as charge balancing agents when preparing ZSM-48 molecular sieves. Alcohols are soluble in water, and their molecular size is between that of water molecules and structure-directing agents (i.e., template agents, including first template agents and second template agents). They can enter the pores and can replace part of the water molecules during the synthesis of the molecular sieve to support / fill the pores. The hydroxyl groups contained in the alcohols form hydrogen bonds with the inorganic anion skeleton of the molecular sieve, maintaining the charge balance in the pores, allowing more water molecules in the crystallization system to act as solvents in the system (equivalent to an increase in the water phase), enhancing fluidity, and uniformly dispersing the crystals in the solvent, making it easier to form small-crystal molecular sieves, that is, facilitating the formation of small crystals. In addition, alcohols as charge balancing agents do not change the pH value of the system, thereby avoiding the formation of stray crystals. The added charge balancing agent also facilitates the uniform distribution of the acid sites of the molecular sieve. When the isomerization dewaxing catalyst (whose carrier particles contain the above-mentioned ZSM-48 molecular sieve) is used for hydroisomerization to prepare lubricating oil, the reaction efficiency can be improved.

[0347] 3) In the embodiment of the present invention, a pore-forming agent is used in the preparation of ZSM-48 molecular sieve. Mesopores and micropores can be directly formed during the synthesis of the molecular sieve. When the isomerization dewaxing catalyst (whose carrier particles contain the above-mentioned ZSM-48 molecular sieve) is used to prepare lubricating oil by hydroisomerization, it is beneficial for the diffusion of reactants and products in the pores, thereby improving the diffusion efficiency of reactants and products, improving the reaction efficiency and isomerization conversion rate, reducing the cracking rate, and reducing the amount of molecular sieve used in the catalyst;

[0348] 4) In the preparation of ZSM-48 molecular sieves in the embodiment of the present invention, the gel solution is pre-crystallized at 70-90° C. for 2-6 hours, crystallized at 120-140° C. for 2-6 hours, and crystallized at 140-170° C. for 10-48 hours. The first stage of crystallization forms a primary structure, and the second stage of crystallization forms a large number of crystal nuclei, which is conducive to rapid growth into small crystals under the temperature conditions of the third stage of crystallization. The small crystal molecular sieve has a short pore length, which is conducive to the rapid diffusion of reaction products from the pores and reduces secondary cracking reactions.

[0349] 5) The preparation method of the embodiment of the present invention can directly synthesize short-axis ZSM-molecular sieves, shorten the pore length, and significantly improve the reaction efficiency when the isomerization dewaxing catalyst (whose carrier particles contain the above-mentioned ZSM-48 molecular sieve) is used for hydroisomerization to prepare lubricating oil.

[0350] The above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, substitutions of equivalent components, or equivalent changes and modifications made within the scope of patent protection, should still fall within the scope of this patent. Furthermore, the technical features of this invention may be freely combined with one another, with other technical inventions, and with other technical inventions.

Claims

1. A method for preparing a ZSM-48 molecular sieve, characterized in that: The preparation method of the ZSM-48 molecular sieve comprises: Step 1: Evenly mix an aluminum source, a silicon source, an alkali source, a crystallization inducing agent, a template agent, deionized water, a pore-forming agent and a charge balancing agent to obtain a gel solution; Among them, the aluminum source in terms of Al2O3 and the - The molar ratio of the alkali source, the template, H2O and the silicon source as SiO2 is 0.0025-0.02:0.006-0.38:0.11-1.5:10-50:1; The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.01-0.2:1; The molar ratio of the crystallization inducing agent calculated as M2O to the silicon source calculated as SiO2 is 0.002-0.2:1, wherein M is one or more of alkali metals; The molar ratio of the charge balance agent to H2O is 0.1-1:1; Step 2: pre-crystallize the gel solution at 70-90° C. for 2-6 hours, crystallize at 120-140° C. for 2-6 hours, and crystallize at 140-170° C. for 10-48 hours to obtain a crystallized product; Step 3: washing, drying and calcining the crystallized product to obtain a molecular sieve precursor; Step 4: The molecular sieve precursor is mixed with an ammonium salt, and then washed, dried and calcined to obtain the ZSM-48 molecular sieve.

2. The preparation method according to claim 1, characterized in that: The aluminum source includes one or a combination of aluminum sulfate, sodium aluminate, and aluminum nitrate; The silicon source includes one or a combination of silica sol, white carbon black, and tetraethyl orthosilicate; The alkali source includes NaOH and / or KOH.

3. The preparation method according to claim 1, characterized in that: The template comprises a first template and a second template, and the molar ratio of the first template to the second template is 1-400:

1.

4. The preparation method according to claim 3, characterized in that: The first template agent includes one or a combination of cyclohexylamine, dodecylamine, 1,6-hexanediamine, 1,8-octanediamine and benzylamine, and the second template agent includes one or a combination of hexamethylammonium chloride, hexamethylammonium bromide, ammonium oxalate, ammonium acetate and benzyltriethylammonium bromide.

5. The preparation method according to claim 1, characterized in that: The ammonium salt includes one or a combination of ammonium chloride, ammonium nitrate and ammonium sulfate.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The crystallization inducing agent includes one or a combination of sodium chloride, potassium chloride, sodium sulfate, and potassium sulfate.

7. The preparation method according to any one of claims 1 to 5, characterized in that: The pore-forming agent includes one or a combination of P123, Triton-100, polyhexamethylene biguanide, ammonium chloride, and polyvinyl alcohol.

8. The preparation method according to any one of claims 1 to 5, characterized in that: The charge balancing agent includes one or a combination of glycerol, ethylene glycol, isopropyl alcohol, propanol, and 2-butanol.

9. A ZSM-48 molecular sieve, characterized in that: The ZSM-48 molecular sieve is prepared by the preparation method of the ZSM-48 molecular sieve according to any one of claims 1 to 8.

10. The ZSM-48 molecular sieve according to claim 9, characterized in that: The ZSM-48 molecular sieve has a crystal length of 0.1-0.5 μm, a crystal diameter of 50-100 nm, and an axis-to-diameter ratio of 2-10.

11. An isomerization dewaxing catalyst comprising carrier particles and a noble metal active component supported on the carrier particles, characterized in that: The carrier particles comprise the ZSM-48 molecular sieve according to claim 9 or 10, and the loading amount of the noble metal active component is 0.1-0.5 wt % of the mass of the carrier particles.

12. The isodewaxing catalyst according to claim 11, characterized in that The noble metal active component includes platinum and / or palladium.

13. The isodewaxing catalyst according to claim 11 or 12, characterized in that: The carrier particles are prepared by uniformly mixing the ZSM-48 molecular sieve, alumina, titanium dioxide, an acid solution, a binder, and deionized water, followed by extrusion, drying, and calcination. Among them, the mass ratio of ZSM-48 molecular sieve, alumina, titanium dioxide, acid solution, adhesive and deionized water is 1:0.3-9:0.01-0.5:0.01-0.6:0.3-1:0.2-1.

14. The isodewaxing catalyst according to claim 13, characterized in that The adhesive comprises sesbania powder and / or methyl cellulose; the acid solution comprises a nitric acid or phosphoric acid solution with a concentration of 5-15wt%.

15. The method for preparing the isodewaxing catalyst according to any one of claims 11 to 14, characterized in that: The preparation method comprises: Step (1): dissolving a noble metal salt in a mixed solution of water, alcohol and ligand and mixing them evenly to obtain a noble metal precursor solution; Step (2): impregnating the carrier particles in a noble metal precursor solution, and then drying and calcining the impregnated product to obtain the isomerization dewaxing catalyst.

16. The preparation method according to claim 15, characterized in that: The noble metal salt includes one or a combination of chloroplatinic acid hexahydrate, palladium chloride, platinum dichloride, and ammonium hexachloroplatinate.

17. The preparation method according to claim 15 or 16, characterized in that: The ligand includes one or a combination of sorbic acid, salicylic acid, niacinamide, lactic acid, citric acid, and hyaluronic acid, and the molar ratio of the ligand to the noble metal atom is 6-18:

1.

18. The preparation method according to claim 15 or 16, characterized in that: The alcohol includes one or a combination of ethanol, propanol, isopropanol, and glycerol, and the mass ratio of water to alcohol is 50-1:

1.

19. The preparation method according to claim 15 or 16, characterized in that: In step (2), the calcination is carried out in an air atmosphere at 450-600° C. for 4-14 hours.

20. Use of the isodewaxing catalyst according to any one of claims 11 to 14 in the preparation of lubricating oil by hydroisomerization of heavy feedstock.

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