N-alkane hydroisomerization catalyst and preparation method therefor, composition comprising same, and use thereof

Abstract

An n-alkane hydroisomerization catalyst and a preparation method therefor, a composition comprising same, and a use thereof. The catalyst is obtained by mixing a metal mixed solution containing a modified metal precursor and an active metal precursor with a carrier, then carrying out isovolumetric vacuum impregnation and modification on the basis of programmed heating to obtain a catalyst precursor, and sequentially carrying out homogenization processing and roasting on the catalyst precursor. The modified metal comprises a first modified metal and a second modified metal, the first modified metal comprising one or more of an alkali metal, an alkaline earth metal and a first transition metal, and the second modified metal comprising one or more of a group IIIA metal and a group IVA metal; the active metal comprises a Group VIII metal. The n-alkane hydroisomerization catalyst composition comprises two or three n-alkane hydroisomerization catalysts. The composition has higher heterogeneous selectivity and target product yield, has advantages in pour point and cloud point depressant effects, and has better raw material adaptability.

Description

A normal alkane hydroisomerization catalyst and its preparation method, composition containing the same and application

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on June 30, 2023, with application number 202310794221.X and invention name “A normal alkane hydroisomerization catalyst and its preparation method, composition containing the same and application”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present invention relates to a normal alkane hydroisomerization catalyst and a preparation method thereof, a composition containing the catalyst and applications thereof, and belongs to the technical field of petrochemical industry and molecular sieve catalysts. Background Art

[0003] The hydroisomerization of normal alkanes is an important technical means to produce high-octane gasoline, low-viscosity diesel, and high-grade lubricant base oils. The hydroisomerization catalyst is the core of the technology. The molecular sieve, as the carrier of the hydroisomerization catalyst, takes into account multiple functions such as providing acidic active centers, spatially confined pores, and supporting metal active centers. For the raw materials for the production of the above products, especially lubricant raw materials, their carbon number distribution is wide and their composition is complex. During the hydroisomerization conversion process, the conversion difficulty of molecules with different carbon numbers and structures is different. Therefore, there are differences in the requirements for the active center and pore structure of the catalyst. The catalyst prepared by a single molecular sieve is difficult to meet the conversion requirements of different molecules due to the single acidity and pore structure, resulting in poor activity, low conversion rate, low selectivity and other deficiencies.

[0004] In existing technologies, to achieve pore and acid diversity and meet the conversion requirements of different molecules in the feedstock, the following methods are used: mixing two molecular sieves to prepare hydroisomerization catalysts; preparing composite molecular sieve materials and hydroisomerization catalysts with coexisting crystals of different structures; and combining different molecular sieve catalyst components. However, these methods all suffer from the following drawbacks: complex molecular sieve preparation processes, difficulty in controlling properties, high gas yields, and substandard quality of heavy hydroisomerization products.

[0005] CN105728023A and CN102942958A etc. use one or more molecular sieves to mix and prepare catalysts. Although the mixing of multiple molecular sieves can produce different pore structures and acid centers in the same catalyst, the preparation process of multiple molecular sieves is complicated, and the disordered distribution of pores and acid sites still cannot achieve a good conversion effect in the hydroisomerization process of wide-fraction heavy raw materials. The cloud point of the medium-weight lubricating oil obtained in CN105728023A can only reach -6°C, and the viscosity of 10mm at 100°C is 10mm. 2Heavy base oils with a flow rate of more than 100 / s are difficult to meet the index requirements. When CN102942958A is used for the conversion of different raw materials, it has the disadvantages of high gas yield, low base oil yield, and low pour point depression.

[0006] CN114713281A, CN1762594A, and CN1792451A, among others, prepare hydroisomerization catalysts using materials such as TON / *MRE composites, silica-alumina molecular sieve and SAPO-11 composites, and ZSM-22 / ZSM-23 or ZSM-23 / ZSM-22 composites. While different pore structures and acid centers can be prepared within the same catalyst, the preparation of the composite molecular sieves is complex, requiring the addition of seed crystals for induction or the use of multiple templates for guided synthesis. Controlling the ratio of the components is difficult, and the molecular sieve synthesis formula must be adjusted to achieve conversion of different feedstocks. This results in unstable catalytic performance, hindering stable production.

[0007] CN105214717A uses macromolecular organic amines and alkaline earth metals to adjust the acidity of the catalyst. First, the carrier needs to be modified and dried before loading the metal. The preparation process is complicated, and the single component has limited effect on the conversion of heavy raw materials. In addition, the use of additional organic amines increases the emission of nitride wastewater and exhaust gas during wastewater treatment and roasting, causing serious environmental pollution.

[0008] In addition, although the hydrogen-type molecular sieve used in the above-mentioned prior art as a catalyst carrier has a high initial activity, impurities in the actual reaction raw materials, such as metals and nitrides, will cause rapid poisoning of the medium-strong acid centers, causing the acid centers and metal centers of the catalyst to quickly be in a mismatched state, thereby reducing the catalyst activity stability and service life.

[0009] Therefore, providing a novel n-alkane hydroisomerization catalyst and its preparation method, composition containing the same and application has become a technical problem that needs to be solved urgently in this field.

[0010] Summary of the Invention

[0011] For the hydroisomerization of heavy, highly waxy feedstocks, single molecular sieve catalysts have low isomerization selectivity and insufficient pour point and cloud point depressing capabilities. Furthermore, using a multi-component blend or gradation method requires the preparation of different molecular sieve materials. Due to significant differences in the synthesis and processing methods of these materials, the preparation process is complex and inefficient. To address these shortcomings and deficiencies, one object of the present invention is to provide a catalyst for the hydroisomerization of normal paraffins.

[0012] Another object of the present invention is to provide a method for preparing the above-mentioned n-alkane hydroisomerization catalyst.

[0013] Another object of the present invention is to provide a normal alkane hydroisomerization catalyst composition, which comprises two or more normal alkane hydroisomerization catalysts.

[0014] Another object of the present invention is to provide use of the above-mentioned n-alkane hydroisomerization catalyst or the above-mentioned n-alkane hydroisomerization catalyst composition in the hydroisomerization of waxy feedstock.

[0015] The last object of the present invention is to provide a method for hydroisomerization of a waxy feedstock, which utilizes the above-mentioned n-alkane hydroisomerization catalyst or the above-mentioned n-alkane hydroisomerization catalyst composition to catalyze the hydroisomerization of the waxy feedstock.

[0016] To achieve the above objectives, the present invention provides, in one aspect, a catalyst for the hydroisomerization of normal alkanes, wherein the catalyst for the hydroisomerization of normal alkanes is obtained by first mixing a metal mixed solution containing a modified metal precursor and an active metal precursor with a carrier, performing equal volume vacuum impregnation and modification under a certain vacuum condition according to programmed temperature to obtain a catalyst precursor, and then sequentially homogenizing and calcining the catalyst precursor;

[0017] The modified metal includes a first modified metal and a second modified metal, wherein the first modified metal includes one or a combination of alkali metals, alkaline earth metals and first transition metals, and the second modified metal includes one or a combination of Group IIIA metals and Group IVA metals;

[0018] Active metals include Group VIII metals and the like.

[0019] As a specific embodiment of the above-mentioned n-alkane hydroisomerization catalyst of the present invention, wherein the first modifying metal includes one or a combination of Na, K, Mg, Ca, Ba, Fe and Zn, preferably Mg and / or Ca, and the second modifying metal includes one or a combination of In, Ga and Sn, preferably In;

[0020] The active metal includes one or a combination of Ru, Rh, Pd, Os, Ir and Pt, preferably Pd and / or Pt.

[0021] As a specific embodiment of the above-described n-alkane hydroisomerization catalyst of the present invention, the content of the first modifying metal in the n-alkane hydroisomerization catalyst, calculated as oxide, is 0.1-5 wt%, preferably 0.5-3 wt%, and the molar ratio of the first modifying metal to the second modifying metal is 0.5:1-5:1, preferably 1:1-3:1. The content of the first modifying metal, calculated as oxide, is calculated based on the total weight of the n-alkane hydroisomerization catalyst as 100%.

[0022] As a specific embodiment of the n-alkane hydroisomerization catalyst described above in the present invention, the modified metal precursor includes at least one of the modified metal phosphates, acetates, formates, oxalates, nitrates and sulfonates, etc., preferably at least one of the modified metal phosphates, acetates, formates, oxalates, etc., and more preferably the modified metal acetate.

[0023] In one embodiment of the n-alkane hydroisomerization catalyst of the present invention, the active metal content in the n-alkane hydroisomerization catalyst, calculated as a single substance, is 0.05-1 wt%, preferably 0.1-1 wt%. The active metal content, calculated as a single substance, is calculated based on the total weight of the n-alkane hydroisomerization catalyst as 100%.

[0024] As a specific embodiment of the above-mentioned n-alkane hydroisomerization catalyst of the present invention, the active metal precursor includes at least one of an acid and a salt of the active metal, and is preferably an aminosulfonate or a nitrate of the active metal.

[0025] As a specific embodiment of the above-mentioned n-alkane hydroisomerization catalyst of the present invention, the vacuum degree is 0.01-1 bar.

[0026] As a specific embodiment of the above-mentioned n-alkane hydroisomerization catalyst of the present invention, the temperature program of the programmed temperature increase is: under the conditions of room temperature-30°C and pressure of 0.5-1 bar, immersion for 0.5-5 hours, under the conditions of 40-60°C and pressure of 0.1-0.5 bar, immersion for 0.5-5 hours, and under the conditions of 70-90°C and pressure of 0.01-0.1 bar, immersion for 0.5-5 hours;

[0027] Preferably, the temperature rising program is: immersion for 0.5-1h at room temperature-30°C and pressure of 0.5-0.6bar, immersion for 1-2h at 50°C and pressure of 0.1-0.2bar, and immersion for 2-3h at 70°C and pressure of 0.01-0.05bar.

[0028] As a specific embodiment of the above-mentioned n-alkane hydroisomerization catalyst of the present invention, the homogenization treatment is a homogenization treatment at 100-120° C. for 10-40 hours, preferably 20-30 hours.

[0029] As a specific embodiment of the above-mentioned n-alkane hydroisomerization catalyst of the present invention, the calcination is performed at 300-500° C. for 1-12 h, preferably, the calcination is performed at 400-480° C. for 8-10 h.

[0030] As a specific embodiment of the above-mentioned n-alkane hydroisomerization catalyst of the present invention, the carrier is a molecular sieve carrier, which is prepared by a preparation method comprising the following specific steps:

[0031] Step 1): calcining the molecular sieve raw powder at 550-600°C for 10-24h;

[0032] Step 2): crushing the molecular sieve calcined in step 1) to 100-200 mesh and placing it in a 0.5-5 mol / L, preferably 1 mol / L, ammonium salt solution and stirring at 70-90° C. for 1-2 hours;

[0033] Step 3): Filter the solution treated in step 2), then wash the resulting filter cake with deionized water, filter the washing solution to obtain a filter cake, and then dry the resulting filter cake at 100-120° C. for 10-24 hours. After drying, the moisture content of the molecular sieve is <2 wt%;

[0034] Step 4): The dried molecular sieve prepared in step 3) is crushed to 200-300 mesh and then uniformly mixed with the inorganic porous material, extrusion aid, acid solution, and deionized water. The mixture is then kneaded and extruded into strips. The formed strips are then dried at 100-120°C for 12-24 hours and finally calcined at 550-600°C for 6-12 hours to obtain the carrier.

[0035] As a specific embodiment of the above-mentioned n-alkane hydroisomerization catalyst of the present invention, wherein, in step 1), the molecular sieve includes any one of a ten-membered ring or twelve-membered ring one-dimensional pore molecular sieve.

[0036] As a specific embodiment of the above-mentioned n-alkane hydroisomerization catalyst of the present invention, the molecular sieve includes ZSM-22, ZSM-23, ZSM-48 or ZSM-12.

[0037] As a specific embodiment of the above-mentioned n-alkane hydroisomerization catalyst of the present invention, the SiO2 / Al2O3 molar ratio of the molecular sieve is 20-100, preferably 30-60.

[0038] As a specific embodiment of the above-mentioned n-alkane hydroisomerization catalyst of the present invention, in step 2), the ammonium salt includes one or a combination of ammonium chloride, ammonium nitrate, ammonium sulfate, etc., preferably ammonium chloride.

[0039] As a specific embodiment of the n-alkane hydroisomerization catalyst described above of the present invention, wherein, in step 4), the inorganic porous material comprises at least one of alumina, amorphous silica-alumina, pseudo-boehmite and silica, and is preferably alumina or a mixture of alumina and amorphous silica-alumina;

[0040] The extrusion aid comprises at least one of sesbania powder, methyl cellulose and soluble starch, and is preferably sesbania powder;

[0041] The acid solution includes one of hydrochloric acid, nitric acid, phosphoric acid or sulfuric acid, preferably nitric acid, and its mass concentration is 5-50%, preferably 10-20%.

[0042] As a specific embodiment of the above-mentioned n-alkane hydroisomerization catalyst of the present invention, the average pore diameter of HK micropores of the n-alkane hydroisomerization catalyst is adjustable from 0.50 to 0.75 nm, and the contents of weak Br acid and medium-strong Br acid are adjustable from 0.01 to 0.70 mmol / g, respectively.

[0043] In the present invention, when preparing the n-alkane hydroisomerization catalyst, the diffusion degree of the modified metal can be precisely controlled by adjusting the amount of modified metal and the equal volume vacuum impregnation and calcination procedures, thereby adjusting the acidity of the catalyst, and the pore size can be adjusted by utilizing the distribution degree of the modified metal element at the pore opening and in the pores of the molecular sieve carrier, thereby obtaining catalyst components with different performances.

[0044] In the present invention, when preparing the n-alkane hydroisomerization catalyst, a metal mixed solution containing a modified metal precursor and an active metal precursor is first mixed with a one-dimensional pore carrier, and the carrier is modified and the active metal is loaded simultaneously according to a programmed temperature control under a certain vacuum condition. The main purpose of this operation is to use the modified metal to simultaneously precisely control the acid sites / acid centers and pore size of the carrier to obtain catalyst components with different isomerization properties. At the same time, the modified metal elements assist in anchoring and dispersing the active metal active centers during the loading process, and can effectively prevent the active metal from aggregating, thereby achieving synergy between the active metal active centers and the acid centers, and improving the selectivity and service life of the catalyst. By controlling the amount of modified metal and the preparation procedure, catalyst components with different properties can be obtained.

[0045] On the other hand, the present invention also provides a method for preparing the above-mentioned n-alkane hydroisomerization catalyst, wherein the preparation method comprises:

[0046] Step 1: mixing a modified metal precursor with an acid solution to obtain a modified solution, and then mixing an active metal precursor with the modified solution to obtain a metal mixed solution;

[0047] Step 2: According to the water absorption rate of the carrier, the metal mixed solution is mixed with the carrier and vacuum impregnation and modification are performed at equal volumes according to programmed temperature under a certain vacuum condition to obtain a catalyst precursor;

[0048] Step 3: homogenizing the catalyst precursor to obtain a dry catalyst precursor;

[0049] Step 4: calcining the dried catalyst precursor to obtain a normal alkane hydroisomerization catalyst.

[0050] As a specific embodiment of the preparation method described above of the present invention, in step 1, the acid solution includes at least one of phosphoric acid, formic acid, acetic acid, oxalic acid, boric acid, citric acid and tartaric acid, preferably at least one of phosphoric acid, formic acid, acetic acid, boric acid, citric acid and tartaric acid, and more preferably at least one of acetic acid, citric acid, formic acid, etc.

[0051] As a specific embodiment of the above-mentioned preparation method of the present invention, in step 1, the pH value of the modified solution is 2-6.

[0052] In another aspect, the present invention further provides a normal alkane hydroisomerization catalyst composition, wherein the normal alkane hydroisomerization catalyst composition comprises two or more normal alkane hydroisomerization catalysts.

[0053] As a specific embodiment of the above composition of the present invention, when the n-alkane hydroisomerization catalyst composition comprises three n-alkane hydroisomerization catalysts, the three n-alkane hydroisomerization catalysts are loaded from top to bottom in the n-alkane hydroisomerization reactor and are respectively designated as catalyst A, catalyst B, and catalyst C;

[0054] Wherein, the volume ratio of catalyst A to catalyst B is 1:10-10:1, preferably 1:5-5:1; the volume ratio of catalyst A to catalyst C is 1:10-10:1, preferably 1:5-5:1;

[0055] When the n-alkane hydroisomerization catalyst composition comprises two n-alkane hydroisomerization catalysts, the n-alkane hydroisomerization reactor is filled with catalyst A and catalyst B or catalyst C from top to bottom, and the volume ratio of catalyst A to catalyst B or catalyst C is 1:10-10:1, preferably 1:5-5:1.

[0056] As a specific embodiment of the above composition of the present invention, wherein the weak B acid content of catalyst A at 150°C is 0.01-0.20 mmol / g, and the medium-strong B acid content at 350°C is 0.01-0.20 mmol / g;

[0057] Catalyst B has a weak B acid content of 0.05-0.70 mmol / g at 150°C and a medium-strong B acid content of 0.05-0.70 mmol / g at 350°C;

[0058] Catalyst C has a weak Br acid content of 0.05-0.30 mmol / g at 150°C and a medium-strong Br acid content of 0.05-0.30 mmol / g at 350°C, wherein the ratio of weak Br acid to medium-strong Br acid is 5:1-1:1;

[0059] Preferably, the catalyst A has a weak B acid content of 0.05-0.15 mmol / g at 150°C and a medium-strong B acid content of 0.05-0.15 mmol / g at 350°C;

[0060] Catalyst B has a weak B acid content of 0.30-0.60 mmol / g at 150°C and a medium-strong B acid content of 0.30-0.60 mmol / g at 350°C;

[0061] Catalyst C has a weak B acid content of 0.10-0.20 mmol / g at 150°C and a medium-strong B acid content of 0.10-0.20 mmol / g at 350°C;

[0062] In the catalyst A, catalyst B and catalyst C, the content ratio of weak Br acid to medium-strong Br acid is 2:1-1:1.

[0063] As a specific embodiment of the above composition of the present invention, wherein the average pore size of HK micropores of catalyst A is 0.60-0.75 nm, the average pore size of HK micropores of catalyst component B is 0.50-0.65 nm, and the average pore size of HK micropores of catalyst C is 0.55-0.70 nm;

[0064] Preferably, the average pore diameter of HK micropores of catalyst A is 0.65-0.70 nm, the average pore diameter of HK micropores of catalyst B is 0.55-0.60 nm, and the average pore diameter of HK micropores of catalyst C is 0.60-0.65 nm.

[0065] In another aspect, the present invention further provides the use of the above-described n-alkane hydroisomerization catalyst or the above-described n-alkane hydroisomerization catalyst composition in the hydroisomerization of a waxy feedstock. The use of the above-described n-alkane hydroisomerization catalyst or the above-described n-alkane hydroisomerization catalyst composition in the hydroisomerization of a waxy feedstock catalyzed by the above-described n-alkane hydroisomerization catalyst or the above-described n-alkane hydroisomerization catalyst composition can produce products such as high-quality lubricating base oil, low-viscosity diesel, high-octane gasoline, and biofuel.

[0066] As a specific embodiment of the above application of the present invention, the wax-containing raw material includes bio-deoxygenated oil, hydrocracking tail oil or FT synthetic wax, and the mass content of the wax is 10-100%.

[0067] As a specific embodiment of the above-mentioned application of the present invention, a wax-containing raw material such as biodeoxygenated oil, hydrocracked tail oil, or FT synthetic wax is sequentially subjected to catalyst A, catalyst B, and catalyst C for graded conversion under a certain reaction pressure, reaction temperature, and volumetric space velocity. For the biodeoxygenated oil, after graded conversion, regular vacuum distillation can be performed to obtain bio-jet kerosene and biodiesel, wherein the freezing point of the bio-jet kerosene is ≤ -40°C. For the hydrocracked tail oil, after graded conversion, regular vacuum distillation can be performed to obtain light base oil and medium base oil, wherein the medium base oil has a kinematic viscosity of 4-8 mm at 100°C. 2 / s, pour point ≯-18℃, cloud point ≯-15℃; for FT synthetic wax, light base oil, medium base oil and heavy base oil can be obtained by graded conversion and then regular vacuum distillation, and the heavy base oil has a kinematic viscosity of >10mm at 100℃ 2 / s, viscosity index>150, pour point≯-15℃, cloud point≯-5℃.

[0068] Finally, the present invention also provides a method for hydroisomerization of a waxy feedstock, wherein the method utilizes the above-mentioned n-alkane hydroisomerization catalyst or the above-mentioned n-alkane hydroisomerization catalyst composition to catalyze the hydroisomerization of the waxy feedstock.

[0069] Compared with the prior art, the present invention can achieve the following beneficial technical effects:

[0070] (1) In the preparation of a normal alkane hydroisomerization catalyst, the present invention utilizes a modified metal precursor to prepare a buffer solution, i.e., a modified solution, which is then combined with a noble metal precursor, i.e., an active metal precursor, to form a composite impregnation solution, i.e., a metal mixed solution. Catalyst modification and noble metal loading are accomplished in one step, resulting in a simple preparation process. The steric hindrance and competitive adsorption of the modified metal are utilized to improve the dispersion of the noble metal while effectively preventing and controlling the migration and agglomeration of the noble metal active centers during calcination and use, thereby improving the noble metal dispersion and anti-migration capability, thereby enhancing the activity and service life of the catalyst.

[0071] (2) The present invention controls the amount of modified metal and the modification procedure, i.e., the equal volume vacuum impregnation procedure, and utilizes the migration, selective coverage, and deposition of the modified metal on the acid site and the change in the pore structure caused by the change in charge density to achieve the preparation of different functional catalyst components using a single molecular sieve material. The average pore diameter of the micropores is adjustable from 0.50 to 0.75 nm, and the contents of weak Br and medium-strong Br are adjustable from 0.01 to 0.70 mmol / g, respectively. By grading the various catalyst components, the differences in acidity and pore size can be utilized to achieve graded conversion of different raw materials, thereby improving isomerization selectivity and target product yield, achieving highly selective graded isomerization conversion of raw materials, and solving the problem of complex preparation processes using multiple molecular sieve materials.

[0072] (3) The n-alkane hydroisomerization catalyst composition provided by the present invention is used to catalyze the hydroisomerization reaction of complex mixed long-chain n-alkanes in heavy, highly waxy feedstocks, with higher isomerization selectivity and target product yield, better pour point and cloud point lowering effects, and better feedstock adaptability. That is, the n-alkane hydroisomerization catalyst composition can effectively control cracking side reactions, reduce gas and naphtha yields, increase base oil yield, obtain base oil products with low pour point and cloud point, and can be generally applied to the hydroisomerization reaction of waxy feedstocks. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] 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.

[0074] FIG1 is an NH3-TPD curve of the n-alkane hydroisomerization catalysts provided in Examples 1 to 4 of the present invention and in Comparative Example 1, as well as the n-alkane hydroisomerization catalyst composition provided in Comparative Example 7.

[0075] FIG2 is a spherical aberration-corrected transmission electron micrograph of the n-alkane hydroisomerization catalyst provided in Example 2 of the present invention.

[0076] FIG3 is a spherical aberration-corrected transmission electron microscope image of the normal alkane hydroisomerization catalyst provided in Comparative Example 1.

[0077] FIG4 is a spherical aberration-corrected transmission electron microscope image of the normal alkane hydroisomerization catalyst provided in Comparative Example 1. 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, the term "two" used in this specification means "at least two".

[0084] 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.

[0085] 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.

[0086] Examples of normal alkane hydroisomerization catalysts and related comparative examples

[0087] Example 1

[0088] This embodiment provides a normal alkane hydroisomerization catalyst, which is prepared by a preparation method comprising the following specific steps:

[0089] Preparation of catalyst support:

[0090] Step 1): calcining ZSM-22 raw powder with a silicon-aluminum ratio of 60 at 595°C for 12 hours;

[0091] Step 2): The molecular sieve calcined in step 1) is crushed to 100-200 mesh and then placed in a 1 mol / L ammonium nitrate solution and stirred at 80° C. for 1.5 h;

[0092] Step 3): Filter the solution treated in step 2), then wash the resulting filter cake with deionized water, filter the washing solution to obtain a filter cake, and then dry the resulting filter cake at 120° C. for 24 hours. After drying, the moisture content of the molecular sieve is <2 wt%;

[0093] Step 4): The dried molecular sieve obtained in step 3) is crushed to 200-300 mesh, and 40 g of the crushed molecular sieve is mixed with 10 g of pseudo-boehmite, 3 g of sesbania powder, 19 g of a 15% nitric acid solution, and 16 g of deionized water. The mixture is then kneaded and extruded into strips, which are then dried at 120° C. for 24 h and calcined at 595° C. for 6 h to obtain a catalyst support.

[0094] Preparation of catalyst:

[0095] Step 1: 3.3 g of magnesium acetate and 2.79 g of indium nitrate were mixed with 17.42 g of 1 mol / L acetic acid to obtain a modified solution with a pH of 2-4, 0.31 g of tetraammineplatinum nitrate was dissolved in 3.58 g of water to obtain an active solution, and the active solution was then mixed with the modified solution to obtain a metal mixed solution;

[0096] Step 2: Mixing the metal mixed solution with 30 g of the catalyst support and performing equal volume vacuum impregnation and modification according to programmed temperature under a certain vacuum condition to obtain a catalyst precursor;

[0097] The conditions for equal volume vacuum impregnation and modification are: room temperature -30 ° C, pressure 0.5 bar, impregnation for 4 h, temperature 40 ° C, pressure 0.1 bar, impregnation for 4 h, temperature 70 ° C, pressure 0.01 bar, impregnation for 4 h;

[0098] Step 3: homogenizing the catalyst precursor at 120° C. for 24 hours to obtain a dry catalyst precursor;

[0099] Step 4: calcining the dried catalyst precursor at 480° C. for 10 hours to obtain a normal alkane hydroisomerization catalyst, wherein the first modified metal, i.e., magnesium, content in the normal alkane hydroisomerization catalyst is 2.84% as calculated as oxide, the second modified metal, i.e., indium content, content in the normal alkane hydroisomerization catalyst is 3.9% as calculated as oxide, and the active metal, i.e., platinum content, content in the form of a single substance is 0.48%, wherein the above contents are all calculated based on the total weight of the normal alkane hydroisomerization catalyst as 100%.

[0100] Example 2

[0101] This embodiment provides a normal alkane hydroisomerization catalyst, which is prepared by a preparation method comprising the following specific steps:

[0102] Preparation of catalyst support:

[0103] Step 1): calcining ZSM-23 raw powder with a silicon-aluminum ratio of 60 at 575°C for 18 hours;

[0104] Step 2): The molecular sieve calcined in step 1) is crushed to 100-200 mesh and then placed in a 1 mol / L ammonium nitrate solution and stirred at 80° C. for 1.5 h;

[0105] Step 3): Filter the solution treated in step 2), then wash the resulting filter cake with deionized water, filter the washing solution to obtain a filter cake, and then dry the resulting filter cake at 120° C. for 24 hours. After drying, the moisture content of the molecular sieve is <2 wt%;

[0106] Step 4): The dried molecular sieve obtained in step 3) is crushed to 200-300 mesh, and 40 g of the crushed molecular sieve is mixed with 10 g of pseudo-boehmite, 3 g of sesbania powder, 19 g of a 15% nitric acid solution, and 16 g of deionized water. The mixture is then kneaded and extruded into strips, which are then dried at 120° C. for 24 h and calcined at 575° C. for 8 h to obtain a catalyst support.

[0107] Preparation of catalyst:

[0108] Step 1: 1.7 g of magnesium formate and 3.78 g of indium sulfamate are mixed with 13.4 g of 1 mol / L formic acid to obtain a modified solution having a pH of 2-4, 0.31 g of tetraammineplatinum nitrate is dissolved in 9.88 g of water to obtain an active solution, and the active solution is then mixed with the modified solution to obtain a metal mixed solution;

[0109] Step 2: Mixing the metal mixed solution with 30 g of the catalyst support and performing equal volume vacuum impregnation and modification according to programmed temperature under a certain vacuum condition to obtain a catalyst precursor;

[0110] The conditions for equal volume vacuum impregnation and modification are: room temperature -30 ° C, pressure 0.7 bar, impregnation for 2 h, temperature 50 ° C, pressure 0.3 bar, impregnation for 2 h, temperature 80 ° C, pressure 0.07 bar, impregnation for 2 h;

[0111] Step 3: homogenizing the catalyst precursor at 120° C. for 24 hours to obtain a dry catalyst precursor;

[0112] Step 4: calcining the dried catalyst precursor at 480° C. for 10 hours to obtain a normal alkane hydroisomerization catalyst, wherein the first modified metal, i.e., magnesium, content is 3.0% in terms of oxide, the second modified metal, i.e., indium, content is 4.0% in terms of oxide, and the active metal, i.e., platinum, content is 0.48% in terms of elemental substance. The above contents are all calculated based on the total weight of the normal alkane hydroisomerization catalyst as 100%.

[0113] Example 3

[0114] This embodiment provides a normal alkane hydroisomerization catalyst, which is prepared by a preparation method comprising the following specific steps:

[0115] Preparation of catalyst support:

[0116] Step 1): calcining ZSM-23 raw powder with a silicon-aluminum ratio of 40 at 550°C for 24h;

[0117] Step 2): The molecular sieve calcined in step 1) is crushed to 100-200 mesh and then placed in a 1 mol / L ammonium nitrate solution and stirred at 80° C. for 1.5 h;

[0118] Step 3): Filter the solution treated in step 2), then wash the resulting filter cake with deionized water, filter the washing solution to obtain a filter cake, and then dry the resulting filter cake at 120° C. for 24 hours. After drying, the moisture content of the molecular sieve is <2 wt%;

[0119] Step 4): The dried molecular sieve obtained in step 3) is crushed to 200-300 mesh, and 40 g of the crushed molecular sieve is mixed with 10 g of pseudo-boehmite, 3 g of sesbania powder, 19 g of a 15% nitric acid solution, and 16 g of deionized water. The mixture is then kneaded and extruded into strips, which are then dried at 120° C. for 24 h and calcined at 550° C. for 12 h to obtain a catalyst support.

[0120] Preparation of catalyst:

[0121] Step 1: 0.6 g of magnesium formate and 1.34 g of indium sulfamate are mixed with 4.5 g of 1 mol / L formic acid to obtain a modified solution having a pH of 2-4, 0.31 g of tetraammineplatinum nitrate is dissolved in 17.25 g of water to obtain an active solution, and the active solution is then mixed with the modified solution to obtain a metal mixed solution;

[0122] Step 2: Mixing the metal mixed solution with 30 g of the catalyst support and performing equal volume vacuum impregnation and modification according to programmed temperature under a certain vacuum condition to obtain a catalyst precursor;

[0123] The conditions for equal volume vacuum impregnation and modification are: room temperature -30 ° C, pressure 1.0 bar, impregnation for 1 h, temperature 60 ° C, pressure 0.5 bar, impregnation for 1 h, temperature 90 ° C, pressure 0.1 bar, impregnation for 1 h;

[0124] Step 3: homogenizing the catalyst precursor at 120° C. for 24 hours to obtain a dry catalyst precursor;

[0125] Step 4: calcining the dried catalyst precursor at 480° C. for 10 hours to obtain a normal alkane hydroisomerization catalyst, wherein the first modified metal calculated as oxide, i.e., magnesium content, is 1.1%, the second modified metal calculated as oxide, i.e., indium content, is 1.5%, and the active metal calculated as a single substance, i.e., platinum content, is 0.5%, wherein the above contents are all calculated based on the total weight of the normal alkane hydroisomerization catalyst as 100%.

[0126] Example 4

[0127] This embodiment provides a normal alkane hydroisomerization catalyst, which is prepared by a preparation method comprising the following specific steps:

[0128] Preparation of catalyst support:

[0129] Step 1): calcining ZSM-23 raw powder with a silicon-aluminum ratio of 40 at 550°C for 24h;

[0130] Step 2): The molecular sieve calcined in step 1) is crushed to 100-200 mesh and then placed in a 1 mol / L ammonium nitrate solution and stirred at 80° C. for 1.5 h;

[0131] Step 3): Filter the solution treated in step 2), then wash the resulting filter cake with deionized water, filter the washing solution to obtain a filter cake, and then dry the resulting filter cake at 120° C. for 24 hours. After drying, the moisture content of the molecular sieve is <2 wt%;

[0132] Step 4): The dried molecular sieve obtained in step 3) is crushed to 200-300 mesh, and 40 g of the crushed molecular sieve is mixed with 10 g of pseudo-boehmite, 3 g of sesbania powder, 19 g of a 15% nitric acid solution, and 16 g of deionized water. The mixture is then kneaded and extruded into strips, which are then dried at 120° C. for 24 h and calcined at 550° C. for 8 h to obtain a catalyst support.

[0133] Preparation of catalyst:

[0134] Step 1: 1.1 g of magnesium formate and 2.45 g of indium sulfamate are mixed with 8.9 g of 1 mol / L formic acid to obtain a modified solution having a pH of 2-4, 0.31 g of tetraammineplatinum nitrate is dissolved in 13.6 g of water to obtain an active solution, and the active solution is then mixed with the modified solution to obtain a metal mixed solution;

[0135] Step 2: Mixing the metal mixed solution with 30 g of the catalyst support and performing equal volume vacuum impregnation and modification according to programmed temperature under a certain vacuum condition to obtain a catalyst precursor;

[0136] The conditions for equal volume vacuum impregnation and modification are: room temperature -30 ° C, pressure 0.5 bar, impregnation for 1 h, temperature 50 ° C, pressure 0.1 bar, impregnation for 2 h, temperature 70 ° C, pressure 0.01 bar, impregnation for 2 h;

[0137] Step 3: homogenizing the catalyst precursor at 120° C. for 24 hours to obtain a dry catalyst precursor;

[0138] Step 4: calcining the dried catalyst precursor at 480° C. for 10 hours to obtain a normal alkane hydroisomerization catalyst, wherein the first modified metal, i.e., magnesium, content in the normal alkane hydroisomerization catalyst is 1.9% as calculated as oxide, the second modified metal, i.e., indium content, content in the normal alkane hydroisomerization catalyst is 2.7% as calculated as oxide, and the active metal, i.e., platinum content, content in the form of a single substance is 0.49%, wherein the above contents are all calculated based on the total weight of the normal alkane hydroisomerization catalyst as 100%.

[0139] Example 5

[0140] This embodiment provides a normal alkane hydroisomerization catalyst, which is prepared by a preparation method comprising the following specific steps:

[0141] Preparation of catalyst support:

[0142] Step 1): calcining ZSM-23 raw powder with a silicon-aluminum ratio of 40 at 550°C for 24h;

[0143] Step 2): crushing the molecular sieve calcined in step 1) to 100-200 mesh and placing it in a 2 mol / L ammonium nitrate solution and stirring at 70° C. for 2 h;

[0144] Step 3): Filter the solution treated in step 2), then wash the resulting filter cake with deionized water, filter the washing solution to obtain a filter cake, and then dry the resulting filter cake at 120° C. for 24 hours. After drying, the moisture content of the molecular sieve is <2 wt%;

[0145] Step 4): The dried molecular sieve obtained in step 3) is crushed to 200-300 mesh, and 40 g of the crushed molecular sieve is mixed with 10 g of pseudo-boehmite, 3 g of sesbania powder, 19 g of a 15% nitric acid solution, and 16 g of deionized water. The mixture is then kneaded and extruded into strips, which are then dried at 120° C. for 24 h and calcined at 550° C. for 8 h to obtain a catalyst support.

[0146] Preparation of catalyst:

[0147] Step 1: 1.1 g potassium acetate and 1.14 g stannous chloride were mixed with 8.9 g 1 mol / L formic acid to obtain a modified solution with a pH of 2-4, 0.31 g tetrammine platinum nitrate was dissolved in 13.6 g water to obtain an active solution, and the active solution was then mixed with the modified solution to obtain a metal mixed solution;

[0148] Step 2: Mixing the metal mixed solution with 30 g of the catalyst support and performing equal volume vacuum impregnation and modification according to programmed temperature under a certain vacuum condition to obtain a catalyst precursor;

[0149] The conditions for equal volume vacuum impregnation and modification are: room temperature -30 ° C, pressure 0.5 bar, impregnation for 1 h, temperature 50 ° C, pressure 0.1 bar, impregnation for 2 h, temperature 70 ° C, pressure 0.01 bar, impregnation for 2 h;

[0150] Step 3: homogenizing the catalyst precursor at 120° C. for 24 hours to obtain a dry catalyst precursor;

[0151] Step 4: calcining the dried catalyst precursor at 480° C. for 10 hours to obtain a normal alkane hydroisomerization catalyst, wherein the first modified metal, i.e., potassium, content in the normal alkane hydroisomerization catalyst is 1.6% as calculated as oxide, the second modified metal, i.e., tin, content in the normal alkane hydroisomerization catalyst is 2.9% as calculated as oxide, and the active metal, i.e., platinum, content in the normal alkane hydroisomerization catalyst is 0.49%, wherein the above contents are all calculated based on the total weight of the normal alkane hydroisomerization catalyst as 100%.

[0152] Example 6

[0153] This embodiment provides a normal alkane hydroisomerization catalyst, which is prepared by a preparation method comprising the following specific steps:

[0154] Preparation of catalyst support:

[0155] Step 1): calcining ZSM-23 raw powder with a silicon-aluminum ratio of 40 at 550°C for 24h;

[0156] Step 2): crushing the molecular sieve calcined in step 1) to 100-200 mesh and placing it in a 4 mol / L ammonium nitrate solution and stirring at 70° C. for 1 hour;

[0157] Step 3): Filter the solution treated in step 2), then wash the resulting filter cake with deionized water, filter the washing solution to obtain a filter cake, and then dry the resulting filter cake at 120° C. for 24 hours. After drying, the moisture content of the molecular sieve is <2 wt%;

[0158] Step 4): The dried molecular sieve obtained in step 3) is crushed to 200-300 mesh, and 40 g of the crushed molecular sieve is mixed with 10 g of pseudo-boehmite, 3 g of sesbania powder, 19 g of a 15% nitric acid solution, and 16 g of deionized water. The mixture is then kneaded and extruded into strips, which are then dried at 120° C. for 24 h and calcined at 550° C. for 8 h to obtain a catalyst support.

[0159] Preparation of catalyst:

[0160] Step 1: 1.44 g of zinc acetate and 2.45 g of indium sulfamate were mixed with 8.9 g of 1 mol / L formic acid to obtain a modified solution with a pH of 2-4, 0.31 g of tetraammineplatinum nitrate was dissolved in 13.6 g of water to obtain an active solution, and the active solution was then mixed with the modified solution to obtain a metal mixed solution;

[0161] Step 2: Mixing the metal mixed solution with 30 g of the catalyst support and performing equal volume vacuum impregnation and modification according to programmed temperature under a certain vacuum condition to obtain a catalyst precursor;

[0162] The conditions for equal volume vacuum impregnation and modification are: room temperature -30 ° C, pressure 0.5 bar, impregnation for 1 h, temperature 50 ° C, pressure 0.1 bar, impregnation for 2 h, temperature 70 ° C, pressure 0.01 bar, impregnation for 2 h;

[0163] Step 3: homogenizing the catalyst precursor at 120° C. for 24 hours to obtain a dry catalyst precursor;

[0164] Step 4: calcining the dried catalyst precursor at 480° C. for 10 hours to obtain a normal alkane hydroisomerization catalyst, wherein the first modified metal, i.e., zinc, content in terms of oxide is 2.0% in the normal alkane hydroisomerization catalyst, the second modified metal, i.e., indium content, content in terms of oxide is 2.7%, and the active metal, i.e., platinum content, content in terms of elemental substance is 0.49%, wherein the above contents are all calculated based on the total weight of the normal alkane hydroisomerization catalyst as 100%.

[0165] Example 7

[0166] This embodiment provides a normal alkane hydroisomerization catalyst, which is prepared by a preparation method comprising the following specific steps:

[0167] Preparation of catalyst support:

[0168] Step 1): calcining ZSM-23 raw powder with a silicon-aluminum ratio of 40 at 550°C for 24h;

[0169] Step 2): crushing the molecular sieve calcined in step 1) to 100-200 mesh and placing it in 1 mol / L ammonium nitrate solution and stirring at 90° C. for 1 hour;

[0170] Step 3): Filter the solution treated in step 2), then wash the resulting filter cake with deionized water, filter the washing solution to obtain a filter cake, and then dry the resulting filter cake at 120° C. for 24 hours. After drying, the moisture content of the molecular sieve is <2 wt%;

[0171] Step 4): The dried molecular sieve obtained in step 3) is crushed to 200-300 mesh, and 40 g of the crushed molecular sieve is mixed with 10 g of pseudo-boehmite, 3 g of sesbania powder, 19 g of a 15% nitric acid solution, and 16 g of deionized water. The mixture is then kneaded and extruded into strips, which are then dried at 120° C. for 24 h and calcined at 550° C. for 8 h to obtain a catalyst support.

[0172] Preparation of catalyst:

[0173] Step 1: 1.1 g of magnesium formate and 2.45 g of indium sulfamate are mixed with 8.9 g of 1 mol / L formic acid to obtain a modified solution having a pH of 2-4, 0.44 g of tetraammine palladium nitrate is dissolved in 13.6 g of water to obtain an active solution, and the active solution is then mixed with the modified solution to obtain a metal mixed solution;

[0174] Step 2: Mixing the metal mixed solution with 30 g of the catalyst support and performing equal volume vacuum impregnation and modification according to programmed temperature under a certain vacuum condition to obtain a catalyst precursor;

[0175] The conditions for equal volume vacuum impregnation and modification are: room temperature -30 ° C, pressure 0.5 bar, impregnation for 1 h, temperature 50 ° C, pressure 0.1 bar, impregnation for 2 h, temperature 70 ° C, pressure 0.01 bar, impregnation for 2 h;

[0176] Step 3: homogenizing the catalyst precursor at 120° C. for 24 hours to obtain a dry catalyst precursor;

[0177] Step 4: calcining the dried catalyst precursor at 480° C. for 10 hours to obtain a normal alkane hydroisomerization catalyst, wherein the first modified metal, i.e., magnesium, content in the normal alkane hydroisomerization catalyst is 2.0% as calculated as oxide, the second modified metal, i.e., indium content, content in the normal alkane hydroisomerization catalyst is 2.7% as calculated as oxide, and the active metal, i.e., palladium content, content in the form of a single substance is 0.49%, wherein the above contents are all calculated based on the total weight of the normal alkane hydroisomerization catalyst as 100%.

[0178] Comparative Example 1

[0179] This comparative example provides a normal alkane hydroisomerization catalyst, which is prepared by a preparation method comprising the following specific steps:

[0180] Preparation of catalyst support:

[0181] Step 1): calcining ZSM-23 raw powder with a silicon-aluminum ratio of 40 at 550°C for 24h;

[0182] Step 2): crushing the molecular sieve calcined in step 1) to 100-200 mesh and placing it in 1 mol / L ammonium nitrate solution and stirring at 80° C. for 1 hour;

[0183] Step 3): Filter the solution treated in step 2), then wash the resulting filter cake with deionized water, filter the washing solution to obtain a filter cake, and then dry the resulting filter cake at 120° C. for 24 hours. After drying, the moisture content of the molecular sieve is <2 wt%;

[0184] Step 4): The dried molecular sieve obtained in step 3) is crushed to 200-300 mesh, and 40 g of the crushed molecular sieve is mixed with 10 g of pseudo-boehmite, 3 g of sesbania powder, 19 g of a 15% nitric acid solution, and 16 g of deionized water. The mixture is then kneaded and extruded into strips, which are then dried at 120° C. for 24 h and calcined at 550° C. for 8 h to obtain a catalyst support.

[0185] Preparation of catalyst:

[0186] Step 1: Dissolve 0.31 g of tetraammineplatinum nitrate in 21 g of water to obtain an active solution;

[0187] Step 2: Mixing the active solution with 30 g of the catalyst support and performing equal volume vacuum impregnation and modification according to programmed temperature under a certain vacuum condition to obtain a catalyst precursor;

[0188] The conditions for equal volume vacuum impregnation and modification are: room temperature -30 ° C, pressure 0.5 bar, impregnation for 1 h, temperature 50 ° C, pressure 0.1 bar, impregnation for 2 h, temperature 70 ° C, pressure 0.01 bar, impregnation for 2 h;

[0189] Step 3: homogenizing the catalyst precursor at 120° C. for 24 hours to obtain a dry catalyst precursor;

[0190] Step 4: calcining the dried catalyst precursor at 480° C. for 10 hours to obtain an n-alkane hydroisomerization catalyst. The content of the active metal, i.e., platinum, in the n-alkane hydroisomerization catalyst is 0.49% on a simple basis, wherein the above contents are calculated based on the total weight of the n-alkane hydroisomerization catalyst being 100%.

[0191] Comparative Example 2

[0192] This comparative example provides a normal alkane hydroisomerization catalyst, which is prepared by a preparation method comprising the following specific steps:

[0193] Preparation of catalyst support:

[0194] Step 1): calcining ZSM-23 raw powder with a silicon-aluminum ratio of 40 at 550°C for 24h;

[0195] Step 2): crushing the molecular sieve calcined in step 1) to 100-200 mesh and placing it in 1 mol / L ammonium nitrate solution and stirring at 80° C. for 1 hour;

[0196] Step 3): Filter the solution treated in step 2), then wash the resulting filter cake with deionized water, filter the washing solution to obtain a filter cake, and then dry the resulting filter cake at 120° C. for 24 hours. After drying, the moisture content of the molecular sieve is <2 wt%;

[0197] Step 4): The dried molecular sieve obtained in step 3) is crushed to 200-300 mesh, and 40 g of the crushed molecular sieve is mixed with 10 g of pseudo-boehmite, 3 g of sesbania powder, 19 g of a 15% nitric acid solution, and 16 g of deionized water. The mixture is then kneaded and extruded into strips, which are then dried at 120° C. for 24 h and calcined at 550° C. for 8 h to obtain a catalyst support.

[0198] Preparation of catalyst:

[0199] Step 1: 1.1 g of magnesium formate and 2.45 g of indium sulfamate are mixed with 8.9 g of 1 mol / L formic acid to obtain a modified solution having a pH of 2-4, 0.31 g of tetraammineplatinum nitrate is dissolved in 13.6 g of water to obtain an active solution, and the active solution is then mixed with the modified solution to obtain a metal mixed solution;

[0200] Step 2: Mixing the metal mixed solution with 30 g of the catalyst support and performing equal volume vacuum impregnation and modification according to programmed temperature under a certain vacuum condition to obtain a catalyst precursor;

[0201] The conditions for equal volume vacuum impregnation and modification are: room temperature and pressure 0.1 bar, impregnation for 2 h, temperature 70 ° C, pressure 0.1 bar, impregnation for 2 h;

[0202] Step 3: homogenizing the catalyst precursor at 120° C. for 24 hours to obtain a dry catalyst precursor;

[0203] Step 4: calcining the dried catalyst precursor at 480° C. for 10 hours to obtain a normal alkane hydroisomerization catalyst, wherein the first modified metal, i.e., magnesium, content in the normal alkane hydroisomerization catalyst is 1.9% as calculated as oxide, the second modified metal, i.e., indium content, content in the normal alkane hydroisomerization catalyst is 2.7% as calculated as oxide, and the active metal, i.e., platinum content, content in the form of a single substance is 0.49%, wherein the above contents are all calculated based on the total weight of the normal alkane hydroisomerization catalyst as 100%.

[0204] Comparative Example 3

[0205] This comparative example provides a normal alkane hydroisomerization catalyst, which is prepared by a preparation method comprising the following specific steps:

[0206] Preparation of catalyst support:

[0207] Step 1): calcining ZSM-23 raw powder with a silicon-aluminum ratio of 40 at 550°C for 24h;

[0208] Step 2): crushing the molecular sieve calcined in step 1) to 100-200 mesh and placing it in 1 mol / L ammonium nitrate solution and stirring at 80° C. for 1 hour;

[0209] Step 3): Filter the solution treated in step 2), then wash the resulting filter cake with deionized water, filter the washing solution to obtain a filter cake, and then dry the resulting filter cake at 120° C. for 24 hours. After drying, the moisture content of the molecular sieve is <2 wt%;

[0210] Step 4): The dried molecular sieve obtained in step 3) is crushed to 200-300 mesh, and 40 g of the crushed molecular sieve is mixed with 10 g of pseudo-boehmite, 3 g of sesbania powder, 19 g of a 15% nitric acid solution, and 16 g of deionized water. The mixture is then kneaded and extruded into strips, which are then dried at 120° C. for 24 h and calcined at 550° C. for 8 h to obtain a catalyst support.

[0211] Preparation of catalyst:

[0212] Step 1: 1.1 g of magnesium formate and 8.9 g of 1 mol / L formic acid are mixed to obtain a modified solution having a pH of 2-4, 0.31 g of tetraammineplatinum nitrate is dissolved in 13.6 g of water to obtain an active solution, and the active solution is then mixed with the modified solution to obtain a metal mixed solution;

[0213] Step 2: Mixing the metal mixed solution with 30 g of the catalyst support and performing equal volume vacuum impregnation and modification according to programmed temperature under a certain vacuum condition to obtain a catalyst precursor;

[0214] The conditions for equal volume vacuum impregnation and modification are: room temperature -30 ° C, pressure 0.5 bar, impregnation for 1 h, temperature 50 ° C, pressure 0.1 bar, impregnation for 2 h, temperature 70 ° C, pressure 0.01 bar, impregnation for 2 h;

[0215] Step 3: homogenizing the catalyst precursor at 120° C. for 24 hours to obtain a dry catalyst precursor;

[0216] Step 4: calcining the dried catalyst precursor at 480° C. for 10 hours to obtain a normal alkane hydroisomerization catalyst. In the normal alkane hydroisomerization catalyst, the content of modified metal magnesium calculated as oxide is 1.9%, and the content of active metal, i.e., platinum, calculated as a single substance is 0.49%, wherein the above contents are calculated based on the total weight of the normal alkane hydroisomerization catalyst as 100%.

[0217] The pyridine-infrared analysis data of the n-alkane hydroisomerization catalysts provided in Examples 1 to 4 of the present invention and Comparative Examples 1 to 3 and 7 are shown in Table 1 below.

[0218] Table 1

[0219] The pore structure analysis data of the n-alkane hydroisomerization catalysts provided by Examples 1 to 4 and Comparative Examples 1 to 3 of the present invention are shown in Table 2 below.

[0220] Table 2

[0221] The NH3-TPD curves of the n-alkane hydroisomerization catalysts provided in Examples 1 to 4 of the present invention and in Comparative Example 1, as well as the n-alkane hydroisomerization catalyst composition provided in Comparative Example 7, are shown in FIG1 , and the pyridine infrared data are shown in Table 1 above. As can be seen from FIG1 and Table 1, the present invention can regulate the distribution of acid centers through bimetallic temperature-programmed impregnation modification, and the ratio of weak acid to medium-strong acid is significantly increased compared to the unmodified catalyst in Comparative Example 1. For the catalyst prepared in Comparative Example 3 using single metal temperature-programmed impregnation modification, although the ratio of weak acid to medium-strong acid is increased compared to the unmodified catalyst in Comparative Example 1, the effect is not significant compared to Examples 2 to 4. For the catalyst prepared in Comparative Example 2 without temperature-programmed impregnation modification, its ratio of weak acid to medium-strong acid is lower than that of the unmodified catalyst in Comparative Example 1, and of course lower than that of the catalysts prepared in Examples 2 to 4.

[0222] As can be seen from Table 1 above, in Comparative Example 2, the impregnation modification was not performed according to the programmed temperature required for protection in the present application when preparing the catalyst. Compared with the normal alkane hydroisomerization catalyst provided in Example 4, the weak acid amount of the catalyst prepared in Comparative Example 2 decreased significantly, while the strong acid amount changed little, resulting in a weak acid to strong acid ratio of only 0.956. This shows that the specific programmed temperature used in the present invention can improve the diffusivity of the modified metal during the modification process and achieve precise control of the amount of strong acid. More importantly, it can increase the ratio of the weak acid amount to the strong acid amount.

[0223] During the isomerization reaction of normal alkanes, a high weak acid content is beneficial to the isomerization reaction, while a low medium-strong acid content can reduce the occurrence of cracking side reactions and reduce the yield of gas and light hydrocarbons. Therefore, the present invention can effectively increase the ratio of weak acid to medium-strong acid, thereby improving the isomerization selectivity of the catalyst and the yield of the target product.

[0224] For the ZSM-23 molecular sieve used in the Examples and Comparative Examples, its elliptical channel pore size is 0.45×0.52 nm, and the catalyst prepared therefrom generally has an average HK micropore diameter of about 0.5-0.6 nm. However, as shown in the experimental data in Table 2 above, the present invention can significantly increase the upper limit of the average HK micropore diameter of the n-alkane hydroisomerization catalyst prepared by bimetallic temperature-programmed impregnation modification. For example, for the n-alkane hydroisomerization catalysts provided in Examples 1, 2, 3, and 4, the average HK micropore diameters can reach 0.69 nm, 0.74 nm, 0.65 nm, and 0.68 nm, respectively, while the average HK micropore diameters of the n-alkane hydroisomerization catalysts provided in Comparative Examples 1, 2, and 3 are only 0.49 nm, 0.53 nm, and 0.62 nm.

[0225] A spherical aberration-corrected transmission electron micrograph of the n-alkane hydroisomerization catalyst provided in Example 2 of the present invention is shown in FIG2 , a spherical aberration-corrected transmission electron micrograph of the n-alkane hydroisomerization catalyst provided in Comparative Example 1 is shown in FIG3 , and a spherical aberration-corrected transmission electron micrograph of the n-alkane hydroisomerization catalyst provided in Comparative Example 3 is shown in FIG4 . As can be seen from FIG2 , FIG3 , and FIG4 , in the n-alkane hydroisomerization catalyst provided in Example 2 of the present invention, all the noble metals are in a highly atomically dispersed state, whereas in Comparative Example 1, no metal modification is employed, and the resulting n-alkane hydroisomerization catalyst exhibits obvious metal agglomeration, with agglomerated particles reaching a size of approximately 2 nm. In Comparative Example 3, which employs single metal modification, although the resulting n-alkane hydroisomerization catalyst exhibits no obvious metal particles, FIG4 shows the presence of clusters of approximately 1 nm in the n-alkane hydroisomerization catalyst. In comparison, the steric hindrance and anchoring effects of the dual-modified metals result in highly atomically dispersed noble metals in the n-alkane hydroisomerization catalyst provided by the present invention.

[0226] Examples of normal alkane hydroisomerization catalyst compositions and related comparative examples

[0227] Example 8

[0228] This embodiment provides an n-alkane hydroisomerization catalyst composition, which comprises the n-alkane hydroisomerization catalysts provided in Examples 2, 3, and 4. These three catalysts are respectively designated as catalyst A, catalyst B, and catalyst C. Catalyst A, catalyst B, and catalyst C are loaded from top to bottom in a fixed-bed reactor at a volume ratio of 4:3:3 to form the n-alkane hydroisomerization catalyst composition. The waxy feedstock passes through the three catalyst beds in sequence from top to bottom to complete the graded conversion.

[0229] Comparative Example 4

[0230] This comparative example provides a normal alkane hydroisomerization catalyst composition, which comprises the normal alkane hydroisomerization catalysts provided in Example 2, Example 3, and Example 4. These three catalysts are respectively denoted as catalyst A, catalyst B, and catalyst C. Catalyst A, catalyst B, and catalyst C are loaded from top to bottom in a fixed bed reactor at a volume ratio of 12:1:1 to form a normal alkane hydroisomerization catalyst composition. The waxy feedstock passes through the three catalyst beds in sequence from top to bottom to complete the graded conversion.

[0231] Comparative Example 5

[0232] This comparative example provides a normal alkane hydroisomerization catalyst composition, which comprises the normal alkane hydroisomerization catalysts provided in Example 2, Example 3 and Example 4. These three catalysts are respectively denoted as catalyst A, catalyst B and catalyst C. Catalyst A, catalyst B and catalyst C are loaded from top to bottom in a fixed bed reactor at a volume ratio of 1:12:12 to form a normal alkane hydroisomerization catalyst composition. The waxy feedstock passes through the three catalyst beds in sequence from top to bottom to complete the graded conversion.

[0233] Comparative Example 6

[0234] This comparative example provides a normal alkane hydroisomerization catalyst composition, which comprises the normal alkane hydroisomerization catalysts provided in Example 3, Example 2, and Example 4. These three catalysts are respectively denoted as catalyst A, catalyst B, and catalyst C. Catalyst A, catalyst B, and catalyst C are loaded from top to bottom in a fixed bed reactor at a volume ratio of 4:3:3 to form a normal alkane hydroisomerization catalyst composition. The waxy feedstock passes through the three catalyst beds in sequence from top to bottom to complete the graded conversion.

[0235] Comparative Example 7

[0236] This comparative example provides an n-alkane hydroisomerization catalyst composition, which is obtained by mechanically mixing the n-alkane hydroisomerization catalysts provided in Example 2, Example 3 and Example 4 in a volume ratio of 4:3:3, and loading the mixture into a fixed-bed reactor to form an n-alkane hydroisomerization catalyst system.

[0237] Application Examples and Comparative Application Examples

[0238] Application Example 1

[0239] This application example uses FT synthetic wax as raw material. The properties of the raw material are shown in Table 3. The n-alkane hydroisomerization catalyst composition provided in Example 8 is used. The reaction temperature is 360°C, the pressure is 5 MPa, the hydrogen-to-oil volume ratio is 500:1, and the volume space velocity is 1.0 h -1 The hydroisomerization reaction was carried out under the following conditions, and the product yields and properties of the reaction products obtained by fractional distillation are shown in Table 5.

[0240] Application Example 2

[0241] This application example uses biodeoxygenated oil as raw material. The properties of the raw material are shown in Table 4. The n-alkane hydroisomerization catalyst composition provided in Example 8 is used. The reaction temperature is 330°C and 300°C, the pressure is 5 MPa, the hydrogen-to-oil volume ratio is 300:1, and the volume space velocity is 1.0 h -1 The hydroisomerization reaction was carried out under the following conditions, and the product yields and properties of the reaction products obtained by fractional distillation are shown in Table 6.

[0242] Application Example 3

[0243] This application example uses FT synthetic wax as raw material. The properties of the raw material are shown in Table 3. The n-alkane hydroisomerization catalyst provided in Example 1 is used. The reaction temperature is 360°C, the pressure is 5 MPa, the hydrogen-to-oil volume ratio is 500:1, and the volume space velocity is 1.0 h -1 The hydroisomerization reaction was carried out under the following conditions, and the product yields and properties of the reaction products obtained by fractional distillation are shown in Table 5.

[0244] Application Example 4

[0245] This application example uses FT synthetic wax as raw material. The properties of the raw material are shown in Table 3. The n-alkane hydroisomerization catalyst provided in Example 2 is used. The reaction temperature is 360°C, the pressure is 5 MPa, the hydrogen-to-oil volume ratio is 500:1, and the volume space velocity is 1.0 h -1 The hydroisomerization reaction was carried out under the following conditions, and the product yields and properties of the reaction products obtained by fractional distillation are shown in Table 5.

[0246] Comparative Application Example 1

[0247] This application example uses FT synthetic wax as raw material. The properties of the raw materials are shown in Table 3. The normal alkane hydroisomerization catalyst provided in Comparative Example 1 is used. The reaction temperature is 360°C, the pressure is 5 MPa, the hydrogen-to-oil volume ratio is 500:1, and the volume space velocity is 1.0 h -1 The hydroisomerization reaction was carried out under the following conditions, and the product yields and properties of the reaction products obtained by fractional distillation are shown in Table 5.

[0248] Comparative Application Example 2

[0249] This application example uses FT synthetic wax as raw material. The properties of the raw material are shown in Table 3. The normal alkane hydroisomerization catalyst composition provided in Comparative Example 4 is used. The reaction temperature is 360°C, the pressure is 5 MPa, the hydrogen-to-oil volume ratio is 500:1, and the volume space velocity is 1.0 h -1 The hydroisomerization reaction was carried out under the following conditions, and the product yields and properties of the reaction products obtained by fractional distillation are shown in Table 5.

[0250] Comparative Application Example 3

[0251] This application example uses FT synthetic wax as raw material. The properties of the raw material are shown in Table 3. The normal alkane hydroisomerization catalyst composition provided in Comparative Example 5 is used. The reaction temperature is 360°C, the pressure is 5 MPa, the hydrogen-to-oil volume ratio is 500:1, and the volume space velocity is 1.0 h -1 The hydroisomerization reaction was carried out under the following conditions, and the product yields and properties of the reaction products obtained by fractional distillation are shown in Table 5.

[0252] Comparative Application Example 4

[0253] This application example uses FT synthetic wax as raw material. The properties of the raw material are shown in Table 3. The normal alkane hydroisomerization catalyst composition provided in Comparative Example 6 is used. The reaction temperature is 360°C, the pressure is 5 MPa, the hydrogen-to-oil volume ratio is 500:1, and the volume space velocity is 1.0 h -1 The hydroisomerization reaction was carried out under the following conditions, and the product yields and properties of the reaction products obtained by fractional distillation are shown in Table 5.

[0254] Comparative Application Example 5

[0255] This application example uses FT synthetic wax as raw material. The properties of the raw material are shown in Table 3. The normal alkane hydroisomerization catalyst composition provided in Comparative Example 7 is used. The reaction temperature is 360°C, the pressure is 5 MPa, the hydrogen-to-oil volume ratio is 500:1, and the volume space velocity is 1.0 h -1 The hydroisomerization reaction was carried out under the following conditions, and the product yields and properties of the reaction products obtained by fractional distillation are shown in Table 5.

[0256] Application ratio 6

[0257] This application example uses FT synthetic wax as raw material. The properties of the raw material are shown in Table 3. The normal alkane hydroisomerization catalyst composition provided in Comparative Example 2 is used. The reaction temperature is 360°C, the pressure is 5 MPa, the hydrogen-to-oil volume ratio is 500:1, and the volume space velocity is 1.0 h -1 The hydroisomerization reaction was carried out under the following conditions, and the product yields and properties of the reaction products obtained by fractional distillation are shown in Table 5.

[0258] Table 3

[0259] Table 4

[0260] Table 5

[0261] Note: The yields in Table 5 are all weight yields, which are calculated based on: product mass / raw material mass × 100%.

[0262] As can be seen from the experimental data in Table 5 above, the n-alkane hydroisomerization catalyst composition provided in the embodiments of the present invention can effectively reduce the yield of light hydrocarbons and naphtha, obtain a higher base oil yield and lower product pour point and cloud point, and is suitable for high-yield production of biofuels.

[0263] Specifically, Application Examples 3, 4, Comparative Application Examples 1, and 6 all used a single normal alkane hydroisomerization catalyst to catalyze the hydroisomerization reaction of FT synthetic wax, while Application Example 1 used the normal alkane hydroisomerization catalyst composition provided in Example 8 to catalyze the hydroisomerization reaction of FT synthetic wax. Compared with Application Examples 3, 4, 1, and 6, the yields of light hydrocarbons and naphtha in Application Example 1 were lower, the base oil yields, especially the yields of medium base oil and heavy base oil, were higher, and the pour point and cloud point of the heavy base oil were significantly lower, with the pour point and cloud point being only -21°C and -5°C, respectively. In addition, as can be seen from the comparison of Application Examples 3, 4, and 1, since the normal alkane hydroisomerization catalyst used in Comparative Application Example 1 was not modified with a modified metal, the yields of light hydrocarbons and naphtha in Comparative Application Example 1 were higher, while the yields of medium base oil and heavy base oil were lower. Because the n-alkane hydroisomerization catalyst used in Comparative Application Example 6 was prepared without heating according to the procedure claimed in the present invention, the yields of light hydrocarbons and naphtha decreased compared to Comparative Application Example 1, while the base oil yield increased. However, the pour point and cloud point of the heavy base oil were relatively high. Compared to Application Examples 3 and 4, the pour point and cloud point of the heavy base oil in Comparative Application Example 6 were lower than those in Application Example 3 and were essentially equivalent to those in Application Example 4, yet the yields of light hydrocarbons and naphtha remained high. Therefore, the specific programmed temperature modification used in the examples of the present invention significantly improved the catalyst's isomerization selectivity while reducing the yields of light hydrocarbons and naphtha.

[0264] Although Comparative Application Examples 2-4 also used an n-alkane hydroisomerization catalyst composition to catalyze the hydroisomerization reaction of FT synthetic wax, the n-alkane hydroisomerization catalyst composition, such as the volume ratio of the three catalysts or the weak or medium-strong Brønsted acid content of the three catalysts, did not meet the requirements of this application. The light hydrocarbon and naphtha yields and base oil yields in Comparative Application Examples 2-4 were either similar to or significantly higher than those in Application Example 1, but the pour point and cloud point of the heavy base oil obtained were significantly higher than those in Application Example 1.

[0265] Comparative Application Example 5 also used an n-paraffin hydroisomerization catalyst composition to catalyze the hydroisomerization of FT synthetic wax. However, the n-paraffin hydroisomerization catalyst composition was obtained by mechanically mixing three n-paraffin hydroisomerization catalysts. The light hydrocarbon and naphtha yields in Comparative Application Example 5 were significantly higher than those in Application Example 1, while the heavy base oil yield was significantly lower. Furthermore, the pour point and cloud point of the heavy base oil were significantly higher than those in Application Example 1.

[0266] Table 6

[0267] As can be seen from the experimental data in Table 6 above, using the n-alkane hydroisomerization catalyst composition provided in the embodiments of the present invention to catalyze the hydroisomerization reaction of biodeoxygenated oil, a high jet fuel yield of up to 55% can be achieved in the jet fuel scheme, and the jet fuel freezing point can be as low as -47°C. A high diesel fuel yield of up to 85% can also be achieved in the diesel scheme, and the diesel pour point is only -5°C.

[0268] 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 normal alkane hydroisomerization catalyst, characterized in that: The normal alkane hydroisomerization catalyst is obtained by first mixing a metal mixed solution containing a modified metal precursor and an active metal precursor with a carrier, performing equal volume vacuum impregnation and modification according to programmed temperature increase under a certain vacuum condition to obtain a catalyst precursor, and then sequentially homogenizing and calcining the catalyst precursor; The modified metal includes a first modified metal and a second modified metal, wherein the first modified metal includes one or a combination of alkali metals, alkaline earth metals and first transition metals, and the second modified metal includes one or a combination of IIIA group metals and IVA group metals; Reactive metals include Group VIII metals.

2. The normal alkane hydroisomerization catalyst according to claim 1, characterized in that: The first modified metal includes one or a combination of Na, K, Mg, Ca, Ba, Fe and Zn, and the second modified metal includes one or a combination of In, Ga and Sn; The active metal includes one or a combination of Ru, Rh, Pd, Os, Ir and Pt.

3. The normal alkane hydroisomerization catalyst according to claim 1 or 2, characterized in that: In the normal alkane hydroisomerization catalyst, the content of the first modified metal calculated as oxide is 0.1-5wt%, and the molar ratio of the first modified metal to the second modified metal is 0.5:1-5:

1.

4. The normal alkane hydroisomerization catalyst according to claim 1 or 2, characterized in that: The modified metal precursor includes at least one of phosphate, acetate, formates, oxalates, nitrates and sulfonates of the modified metal.

5. The normal alkane hydroisomerization catalyst according to claim 1 or 2, characterized in that: The content of active metal in the normal alkane hydroisomerization catalyst is 0.05-1wt% based on the single substance.

6. The normal alkane hydroisomerization catalyst according to claim 1 or 2, characterized in that: The active metal precursor includes at least one of an acid and a salt of the active metal.

7. The normal alkane hydroisomerization catalyst according to claim 1, characterized in that: The vacuum degree is 0.01-1 bar.

8. The normal alkane hydroisomerization catalyst according to claim 1 or 7, characterized in that: The temperature rising program of the programmed temperature rising is: immersion for 0.5-5h at room temperature-30°C and pressure of 0.5-1bar, immersion for 0.5-5h at 40-60°C and pressure of 0.1-0.5bar, immersion for 0.5-5h at 70-90°C and pressure of 0.01-0.1bar.

9. The normal alkane hydroisomerization catalyst according to claim 1 or 2, characterized in that: The homogenization treatment is carried out at 100-120° C. for 10-40 hours.

10. The normal alkane hydroisomerization catalyst according to claim 1, characterized in that: The calcination is performed at 300-500° C. for 1-12 hours.

11. The normal alkane hydroisomerization catalyst according to claim 1 or 2, characterized in that: The carrier is a molecular sieve carrier, which is prepared by a preparation method comprising the following specific steps: Step 1): calcining the molecular sieve raw powder at 550-600°C for 10-24h; Step 2): crush the molecular sieve calcined in step 1) to 100-200 mesh, place in 0.5-5 mol / L ammonium salt solution and stir at 70-90° C. for 1-2 h; Step 3): Filter the solution treated in step 2), then wash the obtained filter cake with deionized water, filter the washing solution to obtain a filter cake, and then dry the finally obtained filter cake at 100-120° C. for 10-24 hours, and the moisture content of the molecular sieve after drying is <2wt%; Step 4): crush the dried molecular sieve obtained in step 3) to 200-300 mesh and mix it evenly with the inorganic porous material, extrusion aid, acid solution and deionized water, then knead the mixture and extrude it into strips, dry the shaped material at 100-120°C for 12-24h, and finally calcine it at 550-600°C for 6-12h to obtain the carrier.

12. The normal alkane hydroisomerization catalyst according to claim 11, characterized in that: In step 1), the molecular sieve comprises any one of a ten-membered ring or twelve-membered ring one-dimensional pore molecular sieve.

13. The normal alkane hydroisomerization catalyst according to claim 12, characterized in that: The molecular sieve includes ZSM-22, ZSM-23, ZSM-48 or ZSM-12.

14. The normal alkane hydroisomerization catalyst according to claim 12 or 13, characterized in that: The SiO2 / Al2O3 molar ratio of the molecular sieve is 20-100.

15. The normal alkane hydroisomerization catalyst according to claim 11, characterized in that: In step 2), the ammonium salt includes one or a combination of ammonium chloride, ammonium nitrate and ammonium sulfate.

16. The normal alkane hydroisomerization catalyst according to claim 11, characterized in that: In step 4), the inorganic porous material comprises at least one of alumina, amorphous silica-alumina, pseudo-boehmite and silicon dioxide; The extrusion aid comprises at least one of sesbania powder, methyl cellulose and soluble starch; The acid solution includes one of hydrochloric acid, nitric acid, phosphoric acid or sulfuric acid, and its mass concentration is 5-50%.

17. The normal alkane hydroisomerization catalyst according to claim 1 or 10, characterized in that: The average pore size of HK micropores of the normal alkane hydroisomerization catalyst can be adjusted from 0.50 to 0.75 nm, and the contents of weak B acid and medium-strong B acid can be adjusted from 0.01 to 0.70 mmol / g respectively.

18. The method for preparing the normal alkane hydroisomerization catalyst according to any one of claims 1 to 17, characterized in that: The preparation method comprises: Step 1: mixing a modified metal precursor with an acid solution to obtain a modified solution, and then mixing an active metal precursor with the modified solution to obtain a metal mixed solution; Step 2: According to the water absorption rate of the carrier, the metal mixed solution is mixed with the carrier and placed under a certain vacuum condition. Under the conditions of vacuum impregnation and modification of equal volume according to programmed temperature rise, a catalyst precursor is obtained; Step 3: homogenizing the catalyst precursor to obtain a dry catalyst precursor; Step 4: calcining the dried catalyst precursor to obtain a normal alkane hydroisomerization catalyst.

19. The preparation method according to claim 18, characterized in that: In step 1, the acid solution includes at least one of phosphoric acid, formic acid, acetic acid, oxalic acid, boric acid, citric acid and tartaric acid.

20. The preparation method according to claim 18 or 19, characterized in that: In step 1, the pH value of the modified solution is 2-6.

21. A normal alkane hydroisomerization catalyst composition, characterized in that: The n-alkane hydroisomerization catalyst composition comprises 2 or 3 n-alkane hydroisomerization catalysts according to any one of claims 1 to 17.

22. The composition according to claim 21, characterized in that When the normal alkane hydroisomerization catalyst composition comprises three normal alkane hydroisomerization catalysts, the three normal alkane hydroisomerization catalysts are loaded from top to bottom in the normal alkane hydroisomerization reactor and are respectively recorded as catalyst A, catalyst B and catalyst C; Wherein, the volume ratio of catalyst A to catalyst B is 1:10-10:1; the volume ratio of catalyst A to catalyst C is 1:10-10:1; When the n-alkane hydroisomerization catalyst composition comprises two n-alkane hydroisomerization catalysts, the n-alkane hydroisomerization reactor is filled with catalyst A and catalyst B or catalyst C from top to bottom, and the volume ratio of catalyst A to catalyst B or catalyst C is 1:10-10:

1.

23. The composition according to claim 22, characterized in that When the normal alkane hydroisomerization catalyst composition comprises three normal alkane hydroisomerization catalysts, the three normal alkane hydroisomerization catalysts are loaded from top to bottom in the normal alkane hydroisomerization reactor and are respectively recorded as catalyst A, catalyst B and catalyst C; The volume ratio of catalyst A to catalyst B is 1:5-5:1; the volume ratio of catalyst A to catalyst C is 1:5-5:

1.

24. The composition according to claim 22, characterized in that When the n-alkane hydroisomerization catalyst composition comprises two n-alkane hydroisomerization catalysts, the n-alkane hydroisomerization reactor is filled with catalyst A and catalyst B or catalyst C from top to bottom, and the volume ratio of catalyst A to catalyst B or catalyst C is 1:5-5:

1.

25. The composition according to any one of claims 21 to 24, characterized in that Catalyst A has a weak B acid content of 0.01-0.20 mmol / g at 150°C and a medium-strong B acid content of 0.01-0.20 mmol / g at 350°C; The weak B acid content of catalyst B at 150°C is 0.05-0.70 mmol / g, and the medium-strong B acid content at 350°C is 0.05-0.70 mmol / g; The weak B acid content of catalyst C at 150°C is 0.05-0.30 mmol / g, and the medium-strong B acid content at 350°C is 0.05-0.30mmol / g, wherein the content ratio of weak Br acid to medium-strong Br acid is 5:1-1:

1.

26. The composition according to claim 25, characterized in that Catalyst A has a weak B acid content of 0.05-0.15 mmol / g at 150°C and a medium-strong B acid content of 0.05-0.15 mmol / g at 350°C; Catalyst B has a weak B acid content of 0.30-0.60 mmol / g at 150°C and a medium-strong B acid content of 0.30-0.60 mmol / g at 350°C; Catalyst C has a weak B acid content of 0.10-0.20 mmol / g at 150°C and a medium-strong B acid content of 0.10-0.20 mmol / g at 350°C; In the catalyst A, catalyst B and catalyst C, the content ratio of weak B acid to medium-strong B acid is 2:1-1:

1.

27. The composition according to any one of claims 21 to 24, characterized in that The average pore size of HK micropores of catalyst A is 0.60-0.75 nm, the average pore size of HK micropores of catalyst component B is 0.50-0.65 nm, and the average pore size of HK micropores of catalyst C is 0.55-0.70 nm.

28. The composition according to claim 27, characterized in that The average pore size of HK micropores of catalyst A is 0.65-0.70 nm, the average pore size of HK micropores of catalyst B is 0.55-0.60 nm, and the average pore size of HK micropores of catalyst C is 0.60-0.65 nm.

29. Use of the n-alkane hydroisomerization catalyst according to any one of claims 1 to 17 or the n-alkane hydroisomerization catalyst composition according to any one of claims 21 to 28 in the hydroisomerization of waxy feedstocks.

30. The use according to claim 29, characterized in that The wax-containing raw material includes biodeoxygenated oil, hydrocracking tail oil or FT synthetic wax.

31. A method for hydroisomerization of a waxy feedstock, characterized in that: The method utilizes the normal alkane hydroisomerization catalyst described in any one of claims 1 to 17 or the normal alkane hydroisomerization catalyst composition described in any one of claims 21 to 28 to catalyze the hydroisomerization of a waxy feedstock.

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