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

Abstract

The invention provides a ZSM-48 molecular sieve and a preparation method thereof, an isodewaxing catalyst and a preparation method and application thereof, and the preparation method of the ZSM-48 molecular sieve comprises the following steps: 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 balance agent, then sequentially pre-crystallizing the obtained gel solution at 70-90 DEG C for 2-6 hours, filtering, and drying to obtain the ZSM-48 molecular sieve. The preparation method comprises the following steps: dissolving a ZSM-48 molecular sieve into a solvent, crystallizing at 120-140 DEG C for 2-6 hours, crystallizing at 140-170 DEG C for 10-48 hours, washing, drying and roasting a crystallized product, mixing an obtained molecular sieve precursor with ammonium salt, and washing, drying and roasting to obtain the ZSM-48 molecular sieve. The carrier particles of the isodewaxing catalyst comprise a ZSM-48 molecular sieve. Acidic sites of the molecular sieve are uniformly distributed, and the molecular sieve has a small grain size and a high total BET (Brunauer, Emmett and Teller) specific surface area. The isomerization dewaxing catalyst has the advantages of high reaction efficiency, high isomerization conversion rate and low cracking rate.

Description

Technical Field

[0001] The invention relates to a ZSM-48 molecular sieve and a preparation method thereof, an isomerization dewaxing catalyst and a preparation method and application thereof, and belongs to the technical field of molecular sieve catalysts. Background Art

[0002] The demand for Class II and Class III base oils produced by isomerization dewaxing technology is increasing year by year. Lubricating oil base oil is one of the special products of oil refining and one of the important products for refinery efficiency. Isomerization dewaxing catalysts are mainly used for isomerization dewaxing, supplementary refining and white oil hydrogenation catalyst preparation in lubricating oil hydroisomerization technology. The key technology of isomerization dewaxing is the preparation of precious metal catalysts. For bifunctional catalysts with high isomerization selectivity and low cracking activity, the active metal generally uses precious metals such as Pt and Pd, which play a role in dehydrogenation and hydrogenation of alkanes or olefins; the carrier is mainly a molecular sieve, which provides acidity, pore restriction and shape selectivity during the isomerization reaction. Generally, aluminum phosphate and silicon aluminum molecular sieves with one-dimensional straight pore structure are used. Typical representatives are SAPO-11, ZSM-22, ZSM-23, ZSM-48 and ZSM-12, etc. Its pore confinement and acidic characteristics determine its ability to convert different raw material molecules and the difference in product structure.

[0003] The following briefly introduces some prior art related to the present invention:

[0004] CN 112934258 A discloses a composite molecular sieve and a preparation method thereof, a hydroisomerization catalyst and a method for hydroisomerization of Fischer-Tropsch synthetic oil. The composite molecular sieve has a core-shell structure, the core-shell structure includes a core and a shell covering the core, the core contains a modified ZSM-48 molecular sieve, and the shell contains an MCM-41 molecular sieve; based on the total weight of the composite molecular sieve, the content of the shell is 0.1-50% by weight, and the content of the core is 50-99.9% by weight. The hydroisomerization catalyst prepared by the composite molecular sieve is used for the hydroisomerization reaction of Fischer-Tropsch synthetic oil, has better isomerization selectivity, and can produce high-quality, high-yield lubricating oil base oil. However, the defects of the technology or the shortcomings of the present invention include: the preparation process of the composite molecular sieve catalyst 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 channel dispersion and acidity control are difficult.

[0005] CN 105214718 A discloses a method for preparing an isomerization dewaxing catalyst, wherein a certain amount of alkaline earth metal soluble salt solution is added to modify the catalyst carrier when the catalyst carrier is formed; a solvent thermal-ion exchange method is used in the step of loading the active metal component, wherein the solvent thermal-ion exchange method is to replace water with a solvent, and the active component is loaded on the catalyst carrier by ion exchange under certain temperature and pressure conditions. The prior art also provides an isomerization dewaxing catalyst prepared by the above method, which is used for isomerization dewaxing of lubricating oil fractions to produce low pour point, high viscosity index lubricating oil base oil, and has moderate catalyst acidity, high metal dispersion, and high isomerization dewaxing reaction activity and selectivity, low pour point of lubricating oil base oil, and high yield. However, the defects of the technology or the shortcomings relative to the present invention include: the active component is loaded on the catalyst carrier by solvent thermal-ion exchange under certain temperature and pressure conditions, and volatile small molecule alcohols are used as solvents, which increases the cost and is difficult to control the process.

[0006] CN 105709817 A discloses an isomerization dewaxing catalyst and a preparation method thereof. The preparation method comprises the following steps: firstly embedding a small-grain MTT molecular sieve loaded with hydrogenation active components in organic starch or polyvinyl alcohol, then uniformly mixing with a precursor of a high-temperature resistant inert oxide, and then molding, drying and roasting to obtain an isomerization dewaxing catalyst. The catalyst provided by the prior art is suitable for the isomerization dewaxing process of lubricating oil fractions. Since the amount of molecular sieve in the catalyst is greatly reduced, not only the production cost of the catalyst is greatly reduced, but also the discharge of wastewater that is difficult to treat during the synthesis of the molecular sieve is avoided, and the catalyst has the characteristics of high yield of the target product and low pour point. However, the defects of the technology or the shortcomings relative to the present invention include: the MTT molecular sieve is embedded in organic starch or polyvinyl alcohol, and carbon deposition is generated during the roasting of the organic matter, resulting in blockage of the molecular sieve pores. In addition, the selected organic matter has a large molecular weight, and embedding the molecular sieve therein is not conducive to metal dispersion.

[0007] CN 105800635 A discloses a method for preparing a ZSM-48 molecular sieve with a mesoporous-microporous hierarchical structure, which 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; the initial gel mixture is aged and crystallized, and the crystallized solid product is separated, washed, dried, and roasted to obtain a ZSM-48 molecular sieve with a mesoporous-microporous hierarchical structure. The preparation method has the advantages of being simple, environmentally friendly, and inexpensive. However, the defects of the technology or the shortcomings of the present invention include: starch is used as a mesoporous pore-forming agent, the molecular weight is large, and it is easy to coke and block the pore opening during the roasting process, and the crystallization time is as long as 4-15 days, which is a long crystallization time.

[0008] CN 115108563 A discloses ZSM-48 molecular sieve and its preparation method, low-carbon alkane isomerization catalyst and its preparation method and application. The preparation method of ZSM-48 molecular sieve comprises: (1) mixing aluminum source, alkali source, template agent and deionized water to obtain solution, then adding pore expander, seed crystal and silicon source to the solution to obtain precursor gel; (2) crystallizing the precursor gel, then subjecting the crystallized product to alkali treatment; wherein the pore expander is selected from carbon nanotubes and / or carbon nanofibers. The alkane isomerization catalyst prepared by using the above-prepared ZSM-48 molecular sieve has higher isoalkane selectivity and yield in alkane isomerization reaction, especially in low-carbon alkane isomerization reaction, and has a wide range of application, especially suitable for C5-C12 isomerization to improve the octane number of gasoline. However, the defects of this technology or the shortcomings of the present invention include: the product is subjected to alkali treatment after crystallization, the process is complicated and difficult to control, the wastewater discharge is increased, and the pore openings are easily blocked by coking during the calcination process of the pore expander carbon nanotubes and / or carbon nanofibers.

[0009] In summary, at present, the prior art generally uses pore-forming agents such as starch, polyvinyl alcohol, and carbon nanotubes that do not participate in the synthesis of molecular sieves, but the molecular weight of these pore-forming agents is relatively large, the pore-forming effect is limited, and they are easy to coke and block the pores during the roasting process; or the molecular sieve is embedded in organic starch or polyvinyl alcohol, and coking and carbon deposits are generated 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 prior art is more complicated. For example, the thickness and uniformity of 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 control are difficult.

[0010] Therefore, providing a novel 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 the field. Summary of the invention

[0011] In order to solve the above-mentioned shortcomings and deficiencies, an object of the present invention is to provide a method for preparing ZSM-48 molecular sieve.

[0012] 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.

[0013] Another object of the present invention is to provide an isomerization dewaxing catalyst, the carrier particles of which contain the above-mentioned ZSM-48 molecular sieve.

[0014] Another object of the present invention is to provide a method for preparing the above-mentioned isomerization dewaxing catalyst.

[0015] 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.

[0016] In order to achieve the above objectives, on the one hand, the present invention provides a method for preparing a ZSM-48 molecular sieve, wherein the method for preparing the ZSM-48 molecular sieve comprises:

[0017] 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;

[0018] 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, preferably 0.005-0.01:0.015-0.25:0.2-1:20-40:1;

[0019] 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;

[0020] 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 of alkali metals;

[0021] The molar ratio of the charge balance agent to H2O is 0.1-1:1, preferably 0.2-0.5:1;

[0022] 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;

[0023] Step 3: washing, drying and calcining the crystallized product to obtain a molecular sieve precursor;

[0024] 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.

[0025] As a specific embodiment of the preparation method described above of the present invention, the aluminum source includes one or a combination of aluminum sulfate, sodium aluminate, aluminum nitrate, etc., preferably aluminum sulfate;

[0026] The silicon source includes one or a combination of silica sol, white carbon black, ethyl orthosilicate, etc., preferably silica sol;

[0027] The alkali source includes NaOH and / or KOH and the like.

[0028] As a specific embodiment of the preparation method described above 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.

[0029] 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.

[0030] As a specific embodiment of the preparation method described above of the present invention, the ammonium salt includes one or a combination of ammonium chloride, ammonium nitrate and ammonium sulfate, etc., preferably ammonium chloride.

[0031] As a specific embodiment of the preparation method described above 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.

[0032] As a specific embodiment of the preparation method described above in the present invention, the pore-forming agent includes one or a combination of P123, Triton-100, polyhexamethylene biguanide, ammonium chloride, polyvinyl alcohol, etc., preferably P123.

[0033] As a specific embodiment of the above preparation method of the present invention, the relative molecular weight of the P123 is 4000-8000.

[0034] 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, isopropanol, propanol, 2-butanol, etc., preferably glycerol.

[0035] As a specific embodiment of the preparation method described above 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.

[0036] As a specific embodiment of the preparation method described above, in step 1, the amount of the crystallization inducing agent calculated as M2O is within 5 wt % of the total weight of the gel solution.

[0037] As a specific embodiment of the preparation method described above of the present invention, wherein, in step 1, the uniform mixing is performed at 40-60°C.

[0038] As a specific embodiment of the preparation method described above of the present invention, in step three, the calcination is performed at 500-600° C. for 6-30 hours.

[0039] 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.

[0040] As a specific embodiment of the preparation method described above of the present invention, wherein, in step 4, the calcination is performed at 500-600° C. for 6-40 hours, preferably for 6-30 hours.

[0041] 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 on-site operation needs.

[0042] 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.

[0043] As a specific embodiment of the ZSM-48 molecular sieve described above, the ZSM-48 molecular sieve has a grain length of 0.1-0.5 μm, a grain 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 grain length to the cross-sectional width.

[0044] 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 0.1-0.5wt% of the mass of the carrier particles.

[0045] 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.

[0046] As a specific embodiment of the isomerization dewaxing 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;

[0047] 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, preferably 1:0.5-2:0.02-0.05:0.02-0.5:0.5-0.8:0.5-0.8.

[0048] As a specific embodiment of the isomerized dewaxing catalyst described above in 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.

[0049] 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, adhesive and deionized water, followed by extrusion, drying and calcination at 400-500°C for 6-14 hours.

[0050] In another aspect, the present invention also provides a method for preparing the above-mentioned isodewaxing catalyst, wherein the preparation method comprises:

[0051] 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;

[0052] 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.

[0053] As a specific embodiment of the method for preparing the isodewaxing catalyst described above, the precious metal salt includes one or a combination of chloroplatinic acid hexahydrate, palladium chloride, platinum dichloride, ammonium hexachloroplatinate, etc., preferably chloroplatinic acid hexahydrate.

[0054] As a specific embodiment of the preparation method of the isomeric dewaxing catalyst described above, the ligand includes one or a combination of sorbic acid, salicylic acid, nicotinamide, lactic acid, citric acid, hyaluronic acid, etc., and the molar ratio of the ligand to the noble metal atom is 6-18: 1. In the process of preparing the isomeric dewaxing catalyst, the ligand is complexed with the noble metal atom and loaded on the carrier, which is conducive to the dispersion of the noble metal atoms. The presence of the ligand can also hinder the aggregation of the noble metal to form large particles to a certain extent.

[0055] As a specific embodiment of the method for preparing the isodewaxing catalyst described above in 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.

[0056] 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.

[0057] As a specific embodiment of the method for preparing the isodewaxing catalyst described above, in step (2), the calcination is carried out in an air atmosphere at 400-600°C for 4-14h, preferably at 400-500°C for 6-14h.

[0058] 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 the actual on-site operation needs.

[0059] In the last aspect, the present invention also provides the use of the above-mentioned isodewaxing catalyst in the preparation of lubricating oil by hydroisomerization of heavy raw materials.

[0060] As a specific implementation of the above application of the present invention, the heavy feedstock includes FT wax or hydrocracking tail oil.

[0061] Compared with the prior art, the beneficial technical effects that can be achieved by the present invention include:

[0062] 1) The present invention uses a crystallization inducer when preparing the ZSM-48 molecular sieve, which can induce more crystal nuclei to form quickly, greatly shorten the crystallization time, and reduce the grain size, that is, to form more small-grain molecular sieves, so that the grain length is 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;

[0063] 2) The present invention uses alcohols as charge balancers 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), and can enter the pores. In the process of molecular sieve synthesis, they can replace part of the water molecules to support / fill the pores. The hydroxyl groups contained in the alcohols form hydrogen bonds with the inorganic anion skeleton of the molecular sieve to maintain the charge balance in the pores, so that more water molecules in the crystallization system act as solvents in the system (equivalent to an increase in the water phase), the fluidity is enhanced, the crystals are evenly dispersed in the solvent, and it is easier to form small-crystal molecular sieves, that is, it is conducive to the formation of small crystals; in addition, alcohols as charge balancers will not change the pH value of the system, thereby avoiding the formation of impurities, and the added charge balancer is also conducive to the uniform distribution of the acid sites of the molecular sieve, and when the isomerization dewaxing catalyst (whose carrier particles contain the above-mentioned ZSM-48 molecular sieve) is used for hydrogenation isomerization to prepare lubricating oil, the reaction efficiency can be improved;

[0064] 3) The present invention uses a pore-forming agent when preparing the ZSM-48 molecular sieve, and 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 for hydrogenation isomerization to prepare lubricating oil, 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 in the catalyst;

[0065] 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, wherein 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 molecular sieve of small crystals has a short pore length, which is conducive to the rapid diffusion of reaction products from the pores, thereby reducing secondary cracking reactions;

[0066] 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

[0067] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the description of the embodiments will be briefly introduced below. 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 creative work.

[0068] Figure 1 This is the XRD diagram of the molecular sieve A1 provided in Example 1 of the present invention.

[0069] Figure 2 This is a SEM image of the molecular sieve A1 provided in Example 1 of the present invention.

[0070] Figure 3 This is the XRD pattern of molecular sieve A6 provided in Comparative Example 1.

[0071] Figure 4 This is the SEM image of the molecular sieve A6 provided for Comparative Example 1.

[0072] Figure 5 This is the XRD pattern of molecular sieve A8 provided for comparative example 3.

[0073] Figure 6 This is the SEM image of molecular sieve A8 provided for comparative example 3.

[0074] Figure 7 This is the XRD pattern of molecular sieve A10 provided for comparative example 5.

[0075] Figure 8 This is the XRD pattern of molecular sieve A11 provided for comparative example 6. DETAILED DESCRIPTION

[0076] It should be noted that the term "comprises" 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 device 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 inherent to these processes, methods, products or devices.

[0077] "Scope" disclosed in the present invention is given in the form of lower limit and 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, for a specific parameter, a range of 60-120 and 80-110 is listed, 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.

[0078] In the present invention, unless otherwise specified, the numerical range "ab" represents an abbreviation of any real number combination between a and b, where a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed in the present invention, and "0-5" is just an abbreviation of these numerical combinations.

[0079] 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.

[0080] 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.

[0081] 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 includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0082] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the attached table, drawings and examples. The following described 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 ordinary technicians in the field without making creative work are within the scope of protection of the present invention. If the specific conditions are not specified in the embodiments, they are carried out according to the normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0083] ZSM-48 molecular sieve examples and comparative examples

[0084] Example 1

[0085] This embodiment provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0086] Step 1: 3.22 g aluminum sulfate, 36 g silica sol (40 wt% solid content), 0.06 g NaOH, 0.06 g NaCl, 4.7 g hexamethonium bromide, 1.4 g cyclohexylamine, 24 g deionized water, 0.74 g Triton X-100, and 24 g propylene glycol were mixed at 40° C. to obtain a gel solution;

[0087] 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 calculated as SiO2 is 0.02:0.006:0.11:10:1;

[0088] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.01:1;

[0089] The molar ratio of the crystallization inducing agent calculated as Na2O to the silicon source calculated as SiO2 is 0.002:1;

[0090] The molar ratio of charge balance agent to H2O is 0.1:1;

[0091] The molar ratio of cyclohexylamine to hexamethylammonium bromide is 1:1;

[0092] 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;

[0093] Step 3: washing, drying and calcining the crystallized product at 500° C. for 6 hours to obtain a molecular sieve precursor;

[0094] Step 4: The molecular sieve precursor is mixed with ammonium chloride at 70° C. for 4 hours, and then washed, dried and calcined at 500° C. for 6 hours to obtain the ZSM-48 molecular sieve, which is denoted as molecular sieve A1.

[0095] Example 2

[0096] This embodiment provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0097] 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 uniformly at a temperature of 60° C. to obtain a gel solution;

[0098] 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 calculated as SiO2 is 0.02:0.04:0.12:15:1;

[0099] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.07:1;

[0100] The molar ratio of the crystallization inducing agent calculated as Na2O to the silicon source calculated as SiO2 is 0.02:1;

[0101] The molar ratio of charge balance agent to H2O is 0.98:1;

[0102] The molar ratio of the first template to the second template is 204:1;

[0103] 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;

[0104] Step 3: washing, drying and calcining the crystallized product at 600° C. for 30 hours to obtain a molecular sieve precursor;

[0105] Step 4: The molecular sieve precursor is 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 is designated as molecular sieve A2.

[0106] Example 3

[0107] This embodiment provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0108] Step 1: 0.32 g aluminum nitrate, 18 g tetraethyl 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 isopropanol are mixed uniformly at a temperature of 45° C. to obtain a gel solution;

[0109] 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 calculated as SiO2 is 0.01:0.2:1.5:40:1;

[0110] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.2:1;

[0111] The molar ratio of the crystallization inducing agent calculated as K2O to the silicon source calculated as SiO2 is 0.2:1;

[0112] The molar ratio of charge balance agent to H2O is 0.48:1;

[0113] The molar ratio of the first template to the second template is 85:1;

[0114] 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;

[0115] Step 3: washing, drying and calcining the crystallized product at 550° C. for 20 hours to obtain a molecular sieve precursor;

[0116] Step 4: The molecular sieve precursor is 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 is designated as molecular sieve A3.

[0117] Example 4

[0118] This embodiment provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0119] 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;

[0120] 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 calculated as SiO2 is 0.0026:0.38:0.76:50:1;

[0121] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.01:1;

[0122] The molar ratio of the crystallization inducing agent calculated as K2O to the silicon source calculated as SiO2 is 0.02:1;

[0123] The molar ratio of charge balance agent to H2O is 0.1:1;

[0124] The molar ratio of the first template to the second template is 254:1;

[0125] Step 2: pre-crystallizing the gel solution at 85° C. for 5 h, crystallizing at 135° C. for 5 h, and crystallizing at 160° C. for 30 h to obtain a crystallized product;

[0126] Step 3: washing, drying and calcining the crystallized product at 530° C. for 12 hours to obtain a molecular sieve precursor;

[0127] Step 4: The molecular sieve precursor is mixed with ammonium nitrate at 70° C. for 4 hours, and then washed, dried and calcined at 560° C. for 28 hours to obtain the ZSM-48 molecular sieve, which is designated as molecular sieve A4.

[0128] Example 5

[0129] This embodiment provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0130] Step 1: 0.15 g aluminum nitrate nonahydrate, 18 g silica sol (solid content 40%), 1.2 g NaOH, 0.5 g K2SO4, 10 g dodecylamine, 0.1 g ammonium acetate, 80 g deionized water, 0.2 g ammonium chloride, and 50 g propanol were mixed at 43° C. to obtain a gel solution;

[0131] 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 calculated as SiO2 is 0.0033:0.25:0.46:42.1:1;

[0132] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.03:1;

[0133] The molar ratio of the crystallization inducing agent calculated as K2O to the silicon source calculated as SiO2 is 0.024:1;

[0134] The molar ratio of charge balance agent to H2O is 0.165:1;

[0135] The molar ratio of the first template to the second template is 41.59:1;

[0136] 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;

[0137] Step 3: washing, drying and calcining the crystallized product at 550° C. for 20 hours to obtain a molecular sieve precursor;

[0138] Step 4: The molecular sieve precursor is mixed with ammonium sulfate at 75° C. for 4 hours, and then washed, dried and calcined at 530° C. for 24 hours to obtain the ZSM-48 molecular sieve, which is designated as molecular sieve A5.

[0139] Comparative Example 1

[0140] This comparative example provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0141] 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 isopropanol are mixed uniformly at a temperature of 45° C. to obtain a gel solution;

[0142] 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 calculated as SiO2 is 0.01:0.2:1.5:40:1;

[0143] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.2:1;

[0144] The molar ratio of charge balance agent to H2O is 0.48:1;

[0145] The molar ratio of the first template to the second template is 85:1;

[0146] 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;

[0147] Step 3: washing, drying and calcining the crystallized product at 550° C. for 20 hours to obtain a molecular sieve precursor;

[0148] Step 4: The molecular sieve precursor is 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 is designated as molecular sieve A6.

[0149] Comparative Example 2

[0150] This comparative example provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0151] 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;

[0152] 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 calculated as SiO2 is 0.01:0.2:1.5:40:1;

[0153] The molar ratio of the crystallization inducing agent calculated as K2O to the silicon source calculated as SiO2 is 0.1:1;

[0154] The molar ratio of the first template to the second template is 85:1;

[0155] 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;

[0156] Step 3: washing, drying and calcining the crystallized product at 550° C. for 20 hours to obtain a molecular sieve precursor;

[0157] Step 4: The molecular sieve precursor is 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 is designated as molecular sieve A7.

[0158] Comparative Example 3

[0159] This comparative example provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0160] Step 1: 0.32 g aluminum nitrate, 18 g tetraethyl 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 uniformly at a temperature of 45° C. to obtain a gel solution;

[0161] 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 calculated as SiO2 is 0.01:0.2:1.5:40:1;

[0162] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.2:1;

[0163] The molar ratio of the crystallization inducing agent calculated as K2O to the silicon source calculated as SiO2 is 0.1:1;

[0164] The molar ratio of the first template to the second template is 85:1;

[0165] 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;

[0166] Step 3: washing, drying and calcining the crystallized product at 550° C. for 20 hours to obtain a molecular sieve precursor;

[0167] Step 4: The molecular sieve precursor is 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 is designated as molecular sieve A8.

[0168] Comparative Example 4

[0169] This comparative example provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0170] Step 1: 0.32 g aluminum nitrate, 18 g tetraethyl 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 isopropanol are mixed uniformly at a temperature of 45° C. to obtain a gel solution;

[0171] 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 calculated as SiO2 is 0.01:0.2:1.5:40:1;

[0172] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.2:1;

[0173] The molar ratio of the crystallization inducing agent calculated as K2O to the silicon source calculated as SiO2 is 0.1:1;

[0174] The molar ratio of charge balance agent to H2O is 0.48:1;

[0175] The molar ratio of the first template to the second template is 85:1;

[0176] Step 2: crystallizing the gel solution at 160° C. for 28 hours to obtain a crystallized product;

[0177] Step 3: washing, drying and calcining the crystallized product at 550° C. for 20 hours to obtain a molecular sieve precursor;

[0178] Step 4: The molecular sieve precursor is 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 is recorded as molecular sieve A9.

[0179] Comparative Example 5

[0180] This embodiment provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0181] Step 1: 3.22 g aluminum sulfate, 36 g silica sol (40 wt% solid content), 0.06 g NaOH, 0.06 g NaCl, 4.7 g hexamethonium bromide, 1.4 g cyclohexylamine, 24 g deionized water, 0.74 g Triton X-100, and 48 g bis(cyclopentadienyl)cobalt were mixed at 40° C. to obtain a gel solution;

[0182] 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 calculated as SiO2 is 0.02:0.006:0.11:10:1;

[0183] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.01:1;

[0184] The molar ratio of the crystallization inducing agent calculated as Na2O to the silicon source calculated as SiO2 is 0.002:1;

[0185] The molar ratio of charge balance agent to H2O is 0.1:1;

[0186] The molar ratio of cyclohexylamine to hexamethylammonium bromide is 1:1;

[0187] 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;

[0188] Step 3: washing, drying and calcining the crystallized product at 500° C. for 6 hours to obtain a molecular sieve precursor;

[0189] Step 4: The molecular sieve precursor is mixed with ammonium chloride at 70° C. for 4 hours, and then 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 silicon aluminum, and is recorded as molecular sieve A10.

[0190] Comparative Example 6

[0191] This embodiment provides a ZSM-48 molecular sieve, which is prepared by a preparation method comprising the following specific steps:

[0192] Step 1: 3.22 g aluminum sulfate, 36 g silica sol (40 wt% solid content), 0.06 g NaOH, 0.06 g NaCl, 4.7 g hexamethonium bromide, 1.4 g cyclohexylamine, 24 g deionized water, 0.74 g Triton X-100, and 29.3 g 1,6-hexanediamine were mixed at 40° C. to obtain a gel solution;

[0193] 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 calculated as SiO2 is 0.02:0.006:0.11:10:1;

[0194] The molar ratio of the pore former to the silicon source calculated as SiO2 is 0.01:1;

[0195] The molar ratio of the crystallization inducing agent calculated as Na2O to the silicon source calculated as SiO2 is 0.002:1;

[0196] The molar ratio of charge balance agent to H2O is 0.1:1;

[0197] The molar ratio of cyclohexylamine to hexamethylammonium bromide is 1:1;

[0198] 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;

[0199] Step 3: washing, drying and calcining the crystallized product at 500° C. for 6 hours to obtain a molecular sieve precursor;

[0200] Step 4: The molecular sieve precursor is mixed with ammonium chloride at 70° C. for 4 hours, and then washed, dried and calcined at 500° C. for 6 hours to obtain the ZSM-48 molecular sieve, which contains ZSM-5 impurities and amorphous silicon aluminum, and is recorded as molecular sieve A11.

[0201] The total BET specific surface area, micropore specific surface area and mesopore specific surface area data of the molecular sieves A1 to A11 provided by Examples 1 to 5 of the present invention and Comparative Examples 1 to 6 are shown in Table 1 below, respectively.

[0202] Table 1

[0203]

[0204] It can be seen from Table 1 above that the molecular sieves A1 to A11 provided in Examples 1 to 5 of the present invention and Comparative Examples 1 to 6 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 of the molecular sieves provided in the embodiments of the present invention.

[0205] The XRD and SEM images of the molecular sieve A1 provided in Example 1 of the present invention are as follows: Figure 1 and Figure 2 As shown, the XRD pattern and SEM pattern of the molecular sieve A6 provided in Comparative Example 1 are respectively as shown in Figure 3 and Figure 4 As shown, the XRD pattern and SEM pattern of the molecular sieve A8 provided in Comparative Example 3 are respectively as shown in Figure 5 and Figure 6 As shown, the XRD pattern of the molecular sieve A10 provided in Comparative Example 5 is as follows Figure 7 As shown, the XRD pattern of the molecular sieve A11 provided in Comparative Example 6 is as follows Figure 8 As shown. Figure 1 , Figure 3 and Figure 5 It can be seen that molecular sieve A1, molecular sieve A6 and molecular sieve A8 are all pure phase ZSM-48 molecular sieves without impurity crystal formation. Figure 2 It can be seen that the crystal length of molecular sieve A1 is 100-500nm, the crystal diameter is 50-100nm, and the axis-to-diameter ratio is about 2-10, indicating that it is a short-axis ZSM-molecular sieve. Figure 2 , Figure 4 and Figure 6As can be seen from the experimental data in Table 1, compared with the molecular sieve A1 provided in Example 1, the molecular sieves A6 to A11 provided in Comparative Examples 1 to 6 have larger grain sizes and axial diameter ratios. Figure 7 and Figure 8 It can be seen that in Comparative Examples 5 and 6, non-alcohol charge balancers such as organic metal complexes (bis(cyclopentadienyl)cobalt) and organic amines (1,6-hexanediamine) were added to prepare molecular sieves, respectively. These non-alcohol charge balancers will affect the pH value or structural orientation of the system and are prone to produce impure crystals or amorphous shapes.

[0206] In summary, by comparing the molecular sieve A1 provided in Example 1 and the molecular sieves A10 to A11 provided in Examples 5 to 6, it can be seen that, compared with the bis(cyclopentadiene)cobalt and 1,6-hexanediamine charge balancers used in 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 molecular sieve has smaller parameters such as the grain size and axial diameter ratio.

[0207] Isomerization dewaxing catalyst examples and comparative examples

[0208] Example 6

[0209] This embodiment provides an isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0210] 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 evenly, extruded, dried, and calcined at 400° C. for 6 hours to obtain carrier particles;

[0211] 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;

[0212] 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, wherein the molar ratio of sorbic acid to platinum atoms is 6:1;

[0213] 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 in air for 6 h to obtain an isodewaxing catalyst with a precious metal loading of 0.5 wt%, recorded as catalyst C1.

[0214] Example 7

[0215] This embodiment provides an isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0216] 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;

[0217] 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;

[0218] 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;

[0219] Step (3): 100 g of carrier particles were immersed in the precious metal precursor solution for 4 h, dried at 120 °C for 2 h, and then calcined at 500 °C for 14 h in air atmosphere to obtain an isodewaxing catalyst with a precious metal loading of 0.5 wt%, recorded as catalyst C2.

[0220] Example 8

[0221] This embodiment provides an isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0222] 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 evenly, extruded, dried, and calcined at 450° C. for 10 hours to obtain carrier particles;

[0223] 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;

[0224] 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;

[0225] 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 450 °C for 10 h in air atmosphere to obtain an isodewaxing catalyst with a precious metal loading of 0.3 wt%, recorded as catalyst C3.

[0226] Example 9

[0227] This embodiment provides an isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0228] 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 evenly, extruded, dried, and calcined at 480° C. for 12 hours to obtain carrier particles;

[0229] 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;

[0230] Step (2): dissolving 0.46 g of ammonium hexachloroplatinate in a mixed solution of 40 g of water, 10 g of glycerol and 1.9 g of nicotinamide ligand, and mixing 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;

[0231] Step (3): 100 g of carrier particles are immersed in the precious metal precursor solution for 2 h. After the immersion, they are dried at 100 °C for 2 h. Then, they are calcined at 480 °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 C4.

[0232] Example 10

[0233] This embodiment provides an isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0234] 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 evenly, extruded, dried, and calcined at 480° C. for 12 hours to obtain carrier particles;

[0235] 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;

[0236] Step (2): dissolving 0.46 g of ammonium hexachloroplatinate in 40 g of water, 10 g of glycerol and 1.98 g of a citric acid monohydrate ligand mixture, and mixing 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;

[0237] 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 600 °C for 12 h in air atmosphere to obtain an isodewaxing catalyst with a precious metal loading of 0.2 wt%, recorded as catalyst C5.

[0238] Embodiment 11

[0239] This embodiment provides an isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0240] 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 evenly, extruded, dried, and calcined at 480° C. for 12 hours to obtain carrier particles;

[0241] 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;

[0242] Step (2): dissolving 0.46 g of ammonium hexachloroplatinate in a mixed solution of 40 g of water, 10 g of glycerol and 26 g of hyaluronic acid (Mn≈3500) ligands, and mixing at 34° C. for 2 h to obtain a noble metal precursor solution, wherein the molar ratio of nicotinamide to platinum atoms is 7.17:1;

[0243] Step (3): 100 g of carrier particles are immersed in the precious metal precursor solution for 2 h. After the immersion, they are dried at 100 °C for 2 h. Then, they are calcined 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.

[0244] Comparative Example 7

[0245] This comparative example provides an isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0246] Step (1): 20 g of molecular sieve A6, 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 evenly, extruded, dried, and calcined at 450° C. for 10 hours to obtain carrier particles;

[0247] 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;

[0248] Step (2): dissolving 0.42 g of platinum dichloride in 50 g of water, 2 g of isopropanol and 1.71 g of a mixed solution of a lactic acid ligand, 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;

[0249] Step (3): 100 g of carrier particles are immersed in the precious metal precursor solution for 2 h. After the immersion, they are dried at 100 °C for 2 h. Then, they are calcined 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 C7.

[0250] Comparative Example 8

[0251] This comparative example provides an isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0252] 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 evenly, extruded, dried, and calcined at 450° C. for 10 hours to obtain carrier particles;

[0253] 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;

[0254] Step (2): dissolving 0.42 g of platinum dichloride in 50 g of water, 2 g of isopropanol and 1.71 g of a mixed solution of a lactic acid ligand, 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;

[0255] 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 450 °C for 10 h in air atmosphere to obtain an isodewaxing catalyst with a precious metal loading of 0.3 wt%, recorded as catalyst C8.

[0256] Comparative Example 9

[0257] This comparative example provides an isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0258] 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 evenly, extruded, dried, and calcined at 450° C. for 10 hours to obtain carrier particles;

[0259] 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;

[0260] Step (2): dissolving 0.42 g of platinum dichloride in 50 g of water, 2 g of isopropanol and 1.71 g of a mixed solution of a lactic acid ligand, 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;

[0261] Step (3): 100 g of carrier particles are immersed in the precious metal precursor solution for 2 h. After the immersion, they are dried at 100 °C for 2 h. Then, they are calcined 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.

[0262] Comparative Example 10

[0263] This comparative example provides an isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0264] 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 evenly, extruded, dried, and calcined at 450° C. for 10 hours to obtain carrier particles;

[0265] The mass ratio of each component is: molecular sieve: alumina: titanium dioxide: acid solution: binder: deionized water = 1: 0.2: 0.04: 0.06: 0.1: 0.16;

[0266] 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;

[0267] 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 450 °C for 10 h in air atmosphere to obtain an isodewaxing catalyst with a precious metal loading of 0.3 wt%, recorded as catalyst C10.

[0268] Comparative Example 11

[0269] This comparative example provides an isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0270] Step (1): 100 g of molecular sieve A10, 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 evenly, extruded, dried, and calcined at 400° C. for 6 hours to obtain carrier particles;

[0271] The mass ratio of each component is: molecular sieve A10: alumina: titanium dioxide: acid solution: binder: deionized water = 1: 0.3: 0.01: 0.01: 0.3: 0.2;

[0272] 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, wherein the molar ratio of sorbic acid to platinum atoms is 6:1;

[0273] 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 in air for 6 h to obtain an isodewaxing catalyst with a precious metal loading of 0.5 wt%, recorded as catalyst C11.

[0274] The acidity data of catalysts C1 to C10 provided in Examples 6 to 11 of the present invention and Comparative Examples 7 to 11 are shown in Table 2 below.

[0275] Table 2

[0276]

[0277]

[0278] As can be seen from Table 2, the contents of weak B acid (200°C) and medium-strong B acid (350°C) of the isomerization dewaxing catalysts provided in Examples 6 to 11 of the present invention are significantly higher than those of the isomerization dewaxing catalysts provided in Comparative Examples 7 to 9 and 11. When these isomerization dewaxing catalysts are used for hydroisomerization to prepare lubricating oil, the reaction efficiency can be significantly improved. For C11 in Comparative Example 11, since the molecular sieve A10 used therein contains ZSM-5 impurities and amorphous silica-alumina, the contents of weak B acid (200°C) and medium-strong B acid (350°C) of C11 are lower than those of C1-C6. Comparing the data of C1-C6 and C10, it can be seen that although the contents of weak B acid (200℃) and medium-strong B acid (350℃) in C10 are roughly equivalent to those in C1-C6, the higher molecular sieve content in C10 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.

[0279] Catalyst Performance Evaluation Example

[0280] 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 micro-reactor performance of C1-C11 was evaluated respectively.

[0281] Among them, the parameters of the hydrocracking tail oil feedstock are shown in Table 3 below.

[0282] Table 3

[0283]

[0284]

[0285] The evaluation results obtained in this evaluation example are shown in Table 4 below.

[0286] Table 4

[0287]

[0288] It can be seen from Table 4 above that the liquid yield, lubricating oil yield and heavy viscosity index of the isomerization dewaxing catalysts provided in Examples 6 to 11 of the present invention are significantly higher than those of the isomerization dewaxing catalysts provided in Comparative Examples 7 to 11, while the heavy base oil pour point and heavy base oil cloud point are significantly lower than those of the isomerization dewaxing catalysts provided in Comparative Examples 7 to 11, indicating that the isomerization dewaxing catalysts provided in the embodiments of the present invention have higher reaction efficiency and isomerization conversion rate, as well as lower cracking rate.

[0289] In summary, compared with the prior art, the beneficial technical effects that can be achieved by the embodiments of the present invention include:

[0290] 1) In the embodiment of the present invention, a crystallization inducer is used when preparing the ZSM-48 molecular sieve, which can induce more crystal nuclei to form quickly, greatly shorten the crystallization time, and reduce the grain size, that is, to form more small-grain molecular sieves, so that the grain length is 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;

[0291] 2) In the embodiment of the present invention, alcohols are used as charge balancers 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), and can enter the pores. In the process of molecular sieve synthesis, they can replace part of the water molecules to support / fill the pores. The hydroxyl groups contained in the alcohols form hydrogen bonds with the inorganic anion skeleton of the molecular sieve to maintain the charge balance in the pores, so that more water molecules in the crystallization system act as solvents in the system (equivalent to an increase in the water phase), the fluidity is enhanced, the crystals are evenly dispersed in the solvent, and it is easier to form small-crystal molecular sieves, that is, it is conducive to the formation of small crystals; in addition, alcohols as charge balancers will not change the pH value of the system, thereby avoiding the formation of impurities, and the added charge balancer is also conducive to the uniform distribution of the acid sites of the molecular sieve, and 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;

[0292] 3) In the embodiment of the present invention, a pore-forming agent is used in the preparation of ZSM-48 molecular sieve, and mesopores and micropores can be directly formed during the synthesis process of the molecular sieve. When the isomerization dewaxing catalyst (whose carrier particles contain the above-mentioned ZSM-48 molecular sieve) is used for hydrogenation isomerization to prepare lubricating oil, 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 in the catalyst;

[0293] 4) In the preparation of ZSM-48 molecular sieve in the embodiment of the present invention, the gel solution is pre-crystallized at 70-90° C. for 2-6 h, crystallized at 120-140° C. for 2-6 h, and crystallized at 140-170° C. for 10-48 h, wherein 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 third stage of crystallization temperature conditions. The molecular sieve of small crystals has a short pore length, which is conducive to the rapid diffusion of reaction products from the pores, thereby reducing secondary cracking reactions;

[0294] 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.

[0295] The above is only a specific embodiment of the present invention, and cannot be used to limit the scope of the invention. Therefore, the replacement of equivalent components, or equivalent changes and modifications made according to the protection scope of the patent of the present invention, should still fall within the scope of this patent. In addition, the technical features of the present invention can be freely combined with each other, with each other and with each other, and with each other.

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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