High-dispersion noble metal isodewaxing catalyst as well as preparation method and application thereof

Abstract

The invention provides a high-dispersion noble metal isodewaxing catalyst as well as a preparation method and application thereof, and the preparation method comprises the following steps: dissolving a noble metal precursor in a mixed solution of water, alcohols and ligands, and uniformly mixing to obtain a noble metal precursor solution; wherein the mass ratio of the water to the alcohols is (20-1): 1, and the molar ratio of the ligand to the noble metal atoms is (6-18): 1; and dipping the carrier particles in a noble metal precursor solution, and carrying out ultrasonic oscillation, drying and roasting in an air atmosphere to obtain the high-dispersion noble metal isodewaxing catalyst, wherein the total weight of the carrier particles is 100%, and the dosage of the noble metal is 0.1-0.6% by atomic mass. The noble metal in the high-dispersion noble metal isomerization dewaxing catalyst provided by the invention is high in dispersion degree, so that the high-dispersion noble metal isomerization dewaxing catalyst has relatively high isomerization dewaxing catalytic activity.

Description

Technical Field

[0001] The invention relates to a highly dispersed noble metal isomerization dewaxing catalyst and a preparation method and application thereof, belonging to the technical field of molecular sieve catalysts. Background Art

[0002] Lubricating oil base oil is one of the special products of oil refining and one of the important products for refinery efficiency. As the market's requirements for high quality and long life of lubricating oil become increasingly stringent, the demand for Class II and III base oils produced by isomerization dewaxing technology is increasing year by year. The precious metal dispersion technology of isomerization dewaxing catalyst is mainly used for isomerization dewaxing, supplementary refining and white oil hydrogenation catalyst preparation in lubricating oil hydroisomerization technology, and lubricating oil isomerization dewaxing technology is the most advanced lubricating oil base oil production technology today. 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 metals are generally precious metals such as Pt and Pd, which play a role in dehydrogenation and hydrogenation of alkanes or olefins. The degree of dispersion of precious metals determines the number of effective metal sites, the precious metal loading and the precious metal hydrogenation performance, which in turn determines the catalyst performance and production cost; the carrier is mainly a molecular sieve, which provides acidity and plays a role in pore restriction and shape selectivity during the isomerization reaction. The molecular sieve generally adopts aluminum phosphate and silicon aluminum molecular sieves with a one-dimensional straight pore structure. Typical representatives are SAPO-11, ZSM-22, ZSM-23, ZSM-48 and ZSM-12. Its pore confinement and acidic characteristics determine that its ability to convert different raw material molecules and product structure are different.

[0003] The following briefly introduces some prior art related to the present invention and the defects of the prior art or the shortcomings of the present invention:

[0004] CN 113694962 A discloses an isomerization dewaxing catalyst for hydrocracking tail oil and a preparation method thereof, wherein two different types of molecular sieves are first ball-milled using a ball mill, then oxides or metal salts containing group VIII B metal elements are added for ball milling, and finally the isomerization dewaxing catalyst is prepared by kneading, extruding, drying and calcining. The defects of this technology or the shortcomings of the present invention include: the use of ball milling may cause the collapse of the molecular sieve pores, and the ball milling does not improve the metal dispersion.

[0005] CN 112915997 A discloses a method for preparing a carbon-loaded highly dispersed noble metal catalyst, which comprises placing a noble metal precursor in a quartz reaction tube of a tubular furnace, heating to more than half of the melting point of the noble metal, i.e., 600-1200°C, so that the noble metal reaches a surface melting state, introducing a carbon-containing gas, wherein the space-time velocity of the carbon-containing gas is 6-600 liters / gram of noble metal per hour, reacting for 1-24 hours, pyrolyzing the carbon-containing gas to produce carbon and hydrogen, and allowing the molten atoms on the surface of the noble metal to freely diffuse and migrate to the unsaturated sites of the newly generated carbon, thereby forming a stable carbon-loaded highly dispersed noble metal catalyst. The defects of this technology or the shortcomings relative to the present invention include: the reaction temperature is relatively high, and it is dangerous to introduce carbon-containing gases such as methane at high temperatures.

[0006] CN 113101969 A discloses a molecular sieve-supported single-atom catalyst and a preparation method thereof, wherein the molecular sieve and a water-soluble metal salt solution are mixed and reacted in a reactor, the solvent of the metal salt solution is selected from at least one of water, methanol, ethanol, propanol, isopropanol and butanol, the temperature of the mixed reaction is 60-150°C, the reaction time is 2-10 days, the unreacted metal salt is removed by filtration or centrifugation to obtain a solid filter block, and then calcined at 500-650°C for 2-12 hours. The defects of this technology or the shortcomings relative to the present invention include: the metal solution directly reacts with the molecular sieve, and metal ions or alcohol molecular sieves easily enter the molecular sieve pores, causing the molecular sieve pores to be blocked.

[0007] CN 111135840 A discloses a method for preparing a supported single-atom dispersed noble metal catalyst, which comprises dissolving a noble metal precursor in deionized water or a common organic solvent, and then adding an appropriate amount of common inorganic or organic reagents containing N, P, and S to obtain a noble metal precursor complex solution (the mass concentration of the noble metal is 0.0001-5%); immersing a certain amount of a carrier in the noble metal precursor complex solution, stirring for 1-600 minutes, filtering, and drying at 60-120° C. for 6-12 hours to obtain a noble metal catalyst precursor; placing a certain amount of the above catalyst precursor in an atmosphere of He, Ar, N2, H2, O2, air, etc., and treating at 200-800° C. for 10-600 seconds to obtain a supported single-atom dispersed noble metal catalyst. The defects of this technology or the shortcomings relative to the present invention include: the common inorganic and organic reagents containing N, P, and S added are not fully burned in the He, Ar, N2, and H2 atmospheres, and the residual N, P, and S elements easily poison and deactivate the catalyst.

[0008] CN 109126774 A discloses an ultra-high dispersion supported single-atom noble metal catalyst and a preparation method thereof, wherein a metal precursor is dissolved in water or ethanol, the obtained solution is impregnated on a carrier, the solvent is evaporated in a water bath at 60-80°C, the mixture is dried in an oven at 100-120°C for 8-24h, and the mixture is calcined at 250-400°C for 4-12h under N2 protection, or reduced at 250-400°C for 4-12h in H2 atmosphere. CO and the pumped halogenated alkane are preheated, vaporized and mixed, and then enter a tubular reactor containing calcined or reduced granular or powdered catalysts. The temperature of the CO and halogenated alkane mixed gas treatment is 50-280°C, the pressure is 0.1-2.0MPa, and the volume space velocity is 100-5000h -1 , the time is 0.1-10h, the molar ratio of CO and halogenated alkane is 0.1-4, the catalyst is first heated to the treatment temperature under the protection of N2 atmosphere, and then switched to CO and halogenated alkane mixed gas treatment, and after treatment, it is cooled to room temperature under the protection of N2 to obtain a supported single-atom noble metal catalyst. The catalyst consists of two parts: metal and carrier, the metal is Ru, Rh, Pd, Ag, Ir, Pt, Au; the metal accounts for 0.01-10.0wt% of the total mass of the catalyst, and the carrier is activated carbon, graphene, silicon oxide, aluminum oxide. The defects of this technology or the shortcomings of the present invention include: the atmosphere process used in the catalyst preparation process is relatively complicated, CO and halogenated alkane gases are dangerous at high temperatures, and industrial production has certain difficulties.

[0009] It can be seen that there are many problems in the current preparation process of highly dispersed precious metal catalysts: P, N, S and other elements are introduced during the preparation of precious metal precursor solutions, and incomplete removal can easily reduce the activity of the catalyst; the precious metal precursors are prepared in a molten state at a high temperature; a complex atmosphere is used during the catalyst roasting process to prevent the precious metals from agglomerating, which is relatively dangerous; operations such as ball milling and impregnation have limited effect on improving the dispersion of precious metals, etc. Therefore, the key research points for improving the dispersion of precious metals and the utilization rate of precious metals in catalysts are to prepare a suitable precious metal precursor solution, reduce the introduction of impurity elements; use a suitable impregnation dispersion process to fully disperse the precious metal precursor on the catalyst surface; use a simple and easy-to-operate roasting process, and prevent the precious metals from agglomerating during the roasting process.

[0010] In summary, providing a new type of highly dispersed precious metal isomerization dewaxing catalyst and its preparation method and application has become a technical problem that needs to be solved urgently in this 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 a highly dispersed precious metal isomerization dewaxing catalyst.

[0012] Another object of the present invention is to provide a highly dispersed noble metal isomerization dewaxing catalyst, which is prepared by the above-mentioned method for preparing the highly dispersed noble metal isomerization dewaxing catalyst. The highly dispersed noble metal isomerization dewaxing catalyst and its preparation method provided by the present invention can solve the problems of noble metal clusters and low effective utilization of noble metals in the preparation of catalysts in the prior art.

[0013] Another object of the present invention is to provide the use of the above-mentioned highly dispersed precious metal isomerization dewaxing catalyst in the preparation of lubricating oil base oil by catalytic isomerization dewaxing reaction.

[0014] Another object of the present invention is to provide a method for preparing lubricating oil base oil by isomerization dewaxing, wherein the catalyst used is the highly dispersed precious metal isomerization dewaxing catalyst described above.

[0015] In order to achieve the above objectives, on the one hand, the present invention provides a method for preparing a highly dispersed precious metal isomerization dewaxing catalyst, wherein the preparation method comprises:

[0016] Step 1: dissolving a noble metal precursor in a mixture of water, alcohol and ligand, and mixing them uniformly to obtain a noble metal precursor solution; wherein the mass ratio of water to alcohol is 20-1:1, preferably 20-5:1, more preferably 10:1, and the molar ratio of ligand to noble metal atom is 6-18:1, preferably 12:1;

[0017] Step 2: Immerse the carrier particles in a precious metal precursor solution, and obtain the highly dispersed precious metal isomerized dewaxing catalyst by ultrasonic vibration, drying and calcining in air atmosphere; wherein, based on the total weight of the carrier particles as 100%, the amount of precious metal used by atomic mass is 0.1-0.6%, preferably 0.2-0.4%.

[0018] As a specific embodiment of the preparation method described above in the present invention, the noble metal precursor is a noble metal salt, and the noble metal salt includes one or a combination of chloroplatinic acid, tetraammine platinum nitrate, platinum nitrate, palladium nitrate, palladium chloride, nickel chloride, nickel nitrate, etc., preferably chloroplatinic acid.

[0019] As a specific embodiment of the preparation method described above of the present invention, the alcohol includes one or a combination of ethanol, propanol, isopropanol, glycerol, etc., preferably ethanol.

[0020] As a specific embodiment of the above preparation method of the present invention, the ligand includes a ligand containing a carboxyl group or a carbonyl group.

[0021] As a specific embodiment of the above preparation method of the present invention, the relative molecular weight of the ligand is 90-200.

[0022] As a specific embodiment of the preparation method described above of the present invention, the ligand includes one or a combination of sorbic acid, salicylic acid, niacinamide, lactic acid, etc., preferably sorbic acid.

[0023] As a specific embodiment of the above preparation method of the present invention, wherein the uniform mixing is mixing at 30-60° C. for 2-6 hours.

[0024] As a specific embodiment of the preparation method described above of the present invention, wherein the ultrasonic oscillation is ultrasonic oscillation at 30-60° C. for 2-6 hours, preferably ultrasonic oscillation at 50° C. for 4 hours.

[0025] As a specific embodiment of the preparation method described above, the carrier particles are obtained by uniformly mixing molecular sieve, alumina, acid solution, binder and deionized water and then kneading and extruding them into strips;

[0026] The mass ratio of molecular sieve, alumina, acid solution, binder and deionized water (excluding deionized water in the acid solution) is 1:0.2-0.6:0.3-0.6:0.01-0.1:0.3-1, preferably 1:0.3-0.5:0.4-0.5:0.05-0.1:0.5-0.8.

[0027] As a specific embodiment of the preparation method described above in the present invention, the molecular sieve includes one or a combination of SAPO-11, SAPO-31, ZSM-12, ZSM-22, ZSM-23, ZSM-48, etc., preferably ZSM-48.

[0028] As a specific embodiment of the above preparation method of the present invention, wherein the acid solution includes nitric acid or phosphoric acid solution with a mass concentration of 5-10wt%, preferably 5-10wt% nitric acid.

[0029] As a specific embodiment of the preparation method described above in the present invention, the adhesive comprises one or a combination of sesbania powder, titanium dioxide, methyl cellulose and the like.

[0030] As a specific embodiment of the preparation method described above, when the adhesive comprises sesbania powder and titanium dioxide or methyl cellulose and titanium dioxide, the mass ratio of sesbania powder or methyl cellulose to titanium dioxide is 10-30:1.

[0031] Preferably, the adhesive comprises sesbania powder and titanium dioxide, and the mass ratio of the sesbania powder to the titanium dioxide is 20:1.

[0032] As a specific embodiment of the preparation method described above of the present invention, the alumina is common alumina such as pseudo-boehmite.

[0033] The present invention does not impose any specific requirements on the size of the carrier particles, and a reasonable size can be selected according to actual on-site operation needs, as long as the purpose of the present invention can be achieved.

[0034] As a specific embodiment of the preparation method described above of the present invention, the drying temperature is 100-120° C., preferably 120° C., and the drying time is 2-4 h, preferably 2 h.

[0035] As a specific embodiment of the preparation method described above of the present invention, the calcination temperature is 450-600°C, preferably 500-550°C, more preferably 550°C, and the calcination time is 4-6h, preferably 6h.

[0036] On the other hand, the present invention also provides a highly dispersed noble metal isomerization dewaxing catalyst, wherein the highly dispersed noble metal isomerization dewaxing catalyst is prepared by the above-mentioned method for preparing the highly dispersed noble metal isomerization dewaxing catalyst, wherein the noble metal is fully dispersed on the surface of the carrier particles and the internal pores thereof, and the noble metal content by atomic mass is 0.1-0.6% based on the total weight of the carrier particles as 100%. The internal pores of the carrier particles are pores formed by the accumulation of molecular sieves.

[0037] In yet another aspect, the present invention further provides the use of the highly dispersed precious metal isomerization dewaxing catalyst described above in the preparation of lubricating oil base oil by catalytic isomerization dewaxing reaction.

[0038] In another aspect, the present invention further provides a method for preparing lubricating oil base oil by isomerization dewaxing, wherein the catalyst used in the method is the highly dispersed precious metal isomerization dewaxing catalyst described above.

[0039] Compared with the prior art, the beneficial technical effects that can be achieved by the present invention include:

[0040] (1) When preparing the precious metal precursor solution, the present invention dissolves the precious metal precursor in a mixed solution of water, alcohols and ligands with a certain molecular size. In the alcohol solvent, the precious metal and the ligand undergo a complexation reaction to form precious metal ligands with larger molecular size, thereby increasing the distance between precious metal atoms and increasing the resistance in the clustering process, thereby preventing the precious metal from clustering during high-temperature roasting and improving the dispersion of the precious metal. In addition, the ligands such as sorbic acid, salicylic acid, and lactic acid used in the present invention contain only one carboxyl group, while nicotinamide contains only one carbonyl group. Compared with citric acid containing three carboxyl groups and oxalic acid containing two carboxyl groups, the ligands used in the present invention have a smaller ability to adjust the pH of the solution, are weaker in acidity, and have less effect on the molecular sieve skeleton structure. Moreover, when the ligand containing one carboxyl group or one carbonyl group complexes with the precious metal atom, more ligands are required, which is beneficial to hinder the formation of metal bonds between precious metal atoms, thereby facilitating metal dispersion.

[0041] (2) The present invention performs ultrasonic vibration after immersing the carrier particles in the precious metal precursor solution, that is, ultrasonic vibration is performed during the immersion process. The ultrasonic vibration can make the precious metal ligands formed above evenly dispersed on the surface of the carrier particles, prevent the precious metals from agglomerating during the drying and roasting process, and improve the dispersion of the precious metals;

[0042] (3) The present invention avoids or reduces the addition of elements such as P, N, and S when preparing the precious metal precursor solution, which can reduce the difficulty of subsequent treatment of the catalyst and thus improve the activity of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] 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.

[0044] Figure 1 This is a STEM image of the precious metal isomerization dewaxing catalyst provided in Example 2 of the present invention.

[0045] Figure 2 This is a STEM image of the precious metal isomerization dewaxing catalyst provided in Example 3 of the present invention.

[0046] Figure 3 This is a STEM image of the precious metal isomerization dewaxing catalyst provided in Example 4 of the present invention.

[0047] Figure 4 This is a STEM image of the precious metal isomerization dewaxing catalyst provided for Comparative Example 1.

[0048] Figure 5This is a STEM image of the precious metal isomerization dewaxing catalyst provided for Comparative Example 2.

[0049] Figure 6 This is a STEM image of the precious metal isomerization dewaxing catalyst provided for Comparative Example 3.

[0050] Figure 7 This is a STEM image of the precious metal isomerization dewaxing catalyst provided for Comparative Example 4. DETAILED DESCRIPTION

[0051] 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.

[0052] "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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] In the present invention, if not specifically stated, the term "two" used in this specification means "at least two".

[0057] 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.

[0058] 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.

[0059] Example 1

[0060] This embodiment provides a noble metal isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0061] Step 1: Weigh 100g ZSM-48 molecular sieve, 20g pseudo-boehmite, 9.23g 65wt% nitric acid, 50.77g deionized water, 4.55g sesbania powder, 0.45g titanium dioxide, and 49.23g deionized water, mix well, knead and extrude into strips to form carrier particles;

[0062] The mass ratio of each component in the carrier is: molecular sieve: alumina: acid solution: binder: deionized water = 1: 0.2: 0.6: 0.05: 0.4923;

[0063] In terms of mass ratio, sesbania powder: titanium dioxide = 10.11:1;

[0064] Step 2: Dissolve 0.21 g of chloroplatinic acid in a mixed solution of 57.14 g of deionized water, 2.86 g of ethanol, and 1.03 g of sorbic acid, and mix at 50° C. for 2 hours to prepare a noble metal precursor solution;

[0065] In the noble metal precursor solution:

[0066] In terms of mass ratio, water: alcohol = 20:1;

[0067] In terms of atomic molar ratio, ligand: noble metal = 18:1;

[0068] In terms of mass ratio, precious metal: carrier particles = 0.1%;

[0069] Step 3: Immerse the carrier particles in the precious metal precursor solution, ultrasonically vibrate at 30° C. for 2 hours, dry at 120° C. for 2 hours, and calcine at 500° C. for 4 hours in an air atmosphere to obtain the precious metal isomerization dewaxing catalyst.

[0070] Example 2

[0071] This embodiment provides a noble metal isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0072] Step 1: Weigh 100g ZSM-48 molecular sieve, 50g alumina, 7.69g 65wt% nitric acid, 42.31g deionized water, 4.76g sesbania powder, 0.24g titanium dioxide, and 37.69g deionized water, mix well, knead and extrude into strips to form carrier particles;

[0073] The mass ratio of each component in the carrier is: molecular sieve: alumina: acid solution: binder: deionized water = 1: 0.5: 0.5: 0.05: 0.3769;

[0074] In terms of mass ratio, sesbania powder: titanium dioxide = 19.83:1;

[0075] Step 2: Dissolve 0.63 g of tetraammine platinum nitrate in a mixed solution of 54.56 g of deionized water, 5.45 g of propanol, and 2.19 g of sorbic acid, and mix at 30° C. for 6 hours to prepare a noble metal precursor solution;

[0076] In the noble metal precursor solution:

[0077] In terms of mass ratio, water: alcohol = 10:1;

[0078] In terms of atomic molar ratio, ligand: noble metal = 12:1;

[0079] In terms of mass ratio, precious metal: carrier = 0.3%;

[0080] Step 3: Immerse the carrier particles in the precious metal precursor solution, ultrasonically vibrate at 40° C. for 4 hours, dry at 120° C. for 2 hours, and calcine at 500° C. for 4 hours in an air atmosphere to obtain the precious metal isomerization dewaxing catalyst.

[0081] Example 3

[0082] This embodiment provides a noble metal isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0083] Step 1: Weigh 100g ZSM-12 molecular sieve, 40g alumina, 4.12g 85wt% phosphoric acid, 45.88g deionized water, 0.95g methyl cellulose, 0.05g titanium dioxide, and 34.12g deionized water, mix well, knead and extrude into strips to form carrier particles;

[0084] The mass ratio of each component in the carrier is: molecular sieve: alumina: acid solution: binder: deionized water = 1: 0.4: 0.5: 0.01: 0.3412;

[0085] In terms of mass ratio, methylcellulose: titanium dioxide = 19:1;

[0086] Step 2: Dissolve 0.49 g of platinum nitrate in a mixed solution of 25 g of deionized water, 25 g of isopropanol, and 1.28 g of salicylic acid, and mix at 60° C. for 3 hours to prepare a noble metal precursor solution;

[0087] In the noble metal precursor solution:

[0088] In terms of mass ratio, water: alcohol = 1:1;

[0089] In terms of atomic molar ratio, ligand: noble metal = 6:1;

[0090] In terms of mass ratio, precious metal: carrier = 0.3%;

[0091] Step 3: Immerse the carrier particles in the precious metal precursor solution, ultrasonically vibrate at 60° C. for 2 hours, dry at 120° C. for 2 hours, and calcine at 550° C. for 6 hours in an air atmosphere to obtain the precious metal isomerization dewaxing catalyst.

[0092] Example 4

[0093] This embodiment provides a noble metal isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0094] Step 1: Weigh 100g ZSM-22 molecular sieve, 50g alumina, 3.69g 65wt% nitric acid, 36.31g deionized water, 6.77g sesbania powder, 0.23g titanium dioxide, and 33.69g deionized water, mix well, knead and extrude into strips to form carrier particles;

[0095] The mass ratio of each component in the carrier is: molecular sieve: alumina: acid solution: binder: deionized water = 1: 0.5: 0.4: 0.07: 0.3369;

[0096] In terms of mass ratio, sesbania powder: titanium dioxide = 29.43:1;

[0097] Step 2: Dissolve 0.65 g of palladium nitrate in a mixed solution of 90.9 g of deionized water, 9.1 g of propylene glycol, and 4.15 g of nicotinamide, and mix at 40° C. for 4 hours to prepare a noble metal precursor solution;

[0098] In the noble metal precursor solution:

[0099] In terms of mass ratio, water: alcohol = 10:1;

[0100] In terms of atomic molar ratio, ligand: noble metal = 12:1;

[0101] In terms of mass ratio, precious metal: carrier = 0.5%;

[0102] Step 3: Immerse the carrier particles in the precious metal precursor solution, ultrasonically vibrate at 40° C. for 2 hours, dry at 120° C. for 4 hours, and calcine at 600° C. for 6 hours in an air atmosphere to obtain the precious metal isomerization dewaxing catalyst.

[0103] Example 5

[0104] This embodiment provides a noble metal isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0105] Step 1: Weigh 100g SAPO-11 molecular sieve, 60g aluminum oxide, 1.76g 85wt% phosphoric acid, 28.24g deionized water, 9.1g sesbania powder, 0.9g titanium dioxide, and 30g deionized water, mix well, knead and extrude into strips to form carrier particles;

[0106] The mass ratio of each component in the carrier is: molecular sieve: alumina: acid solution: binder: deionized water = 1:0.6:0.3:0.1:0.3;

[0107] In terms of mass ratio, sesbania powder: titanium dioxide = 10.11:1;

[0108] Step 2: Dissolve 1 g of palladium chloride in 66.67 g of deionized water, 13.33 g of ethanol, and 6.61 g of lactic acid solution, and mix at 60° C. for 5 hours to prepare a noble metal precursor solution;

[0109] In the noble metal precursor solution:

[0110] In terms of mass ratio, water: alcohol = 5:1;

[0111] In terms of atomic molar ratio, ligand: noble metal = 13:1;

[0112] In terms of mass ratio, precious metal: carrier = 0.6%;

[0113] Step 3: Immerse the carrier particles in the precious metal precursor solution, ultrasonically vibrate at 50° C. for 2 hours, dry at 120° C. for 2 hours, and calcine at 500° C. for 5 hours in an air atmosphere to obtain the precious metal isomerization dewaxing catalyst.

[0114] Example 6

[0115] This embodiment provides a noble metal isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0116] Step 1: Weigh 100g SAPO-11 molecular sieve, 60g aluminum oxide, 1.76g 85wt% phosphoric acid, 28.24g deionized water, 9.1g sesbania powder, 0.9g titanium dioxide, and 30g deionized water, mix well, knead and extrude into strips to form carrier particles;

[0117] The mass ratio of each component in the carrier is: molecular sieve: alumina: acid solution: binder: deionized water = 1:0.6:0.3:0.1:0.3;

[0118] In terms of mass ratio, sesbania powder: titanium dioxide = 10.11:1;

[0119] Step 2: Dissolve 0.89 g of nickel chloride in 64 g of deionized water, 16 g of propanol, and 9.5 g of salicylic acid solution, and mix at 50° C. for 6 hours to prepare a noble metal precursor solution;

[0120] In the noble metal precursor solution:

[0121] In terms of mass ratio, water: alcohol = 4:1;

[0122] In terms of atomic molar ratio, ligand: noble metal = 10:1;

[0123] In terms of mass ratio, precious metal: carrier = 0.4%;

[0124] Step 3: Immerse the carrier particles in the precious metal precursor solution, ultrasonically vibrate at 50° C. for 2 hours, dry at 120° C. for 2 hours, and calcine at 500° C. for 5 hours in an air atmosphere to obtain the precious metal isomerization dewaxing catalyst.

[0125] Example 7

[0126] This embodiment provides a noble metal isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0127] Step 1: Weigh 100g SAPO-11 molecular sieve, 60g aluminum oxide, 1.76g 85wt% phosphoric acid, 28.24g deionized water, 9.1g sesbania powder, 0.9g titanium dioxide, and 30g deionized water, mix well, knead and extrude into strips to form carrier particles;

[0128] The mass ratio of each component in the carrier is: molecular sieve: alumina: acid solution: binder: deionized water = 1:0.6:0.3:0.1:0.3;

[0129] In terms of mass ratio, sesbania powder: titanium dioxide = 10.11:1;

[0130] Step 2: Dissolve 0.94 g of nickel nitrate hexahydrate in 66.67 g of deionized water, 13.33 g of propylene glycol, and 5.1 g of lactic acid solution, and mix at 40° C. for 4 hours to prepare a noble metal precursor solution;

[0131] In the noble metal precursor solution:

[0132] In terms of mass ratio, water: alcohol = 5:1;

[0133] In terms of atomic molar ratio, ligand: noble metal = 11:1;

[0134] In terms of mass ratio, precious metal: carrier = 0.3%;

[0135] Step 3: Immerse the carrier particles in the precious metal precursor solution, ultrasonically vibrate at 50° C. for 2 hours, dry at 120° C. for 2 hours, and calcine at 500° C. for 5 hours in an air atmosphere to obtain the precious metal isomerization dewaxing catalyst.

[0136] Comparative Example 1

[0137] This comparative example provides a noble metal isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0138] Step 1: Weigh 100g ZSM-48 molecular sieve, 20g pseudo-boehmite, 9.23g 65wt% nitric acid, 50.77g deionized water, 4.55g sesbania powder, 0.45g titanium dioxide, and 49.23g deionized water, mix well, knead and extrude into strips to form carrier particles;

[0139] The mass ratio of each component in the carrier is: molecular sieve: alumina: acid solution: binder: deionized water = 1:0.2:0.6:0.05:1;

[0140] In terms of mass ratio, sesbania powder: titanium dioxide = 10.11:1;

[0141] Step 2: Dissolve 0.21 g of chloroplatinic acid in a mixed solution of 57.14 g of deionized water and 2.86 g of ethanol, and mix at 50° C. for 2 hours to prepare a noble metal precursor solution;

[0142] In the noble metal precursor solution:

[0143] In terms of mass ratio, water: alcohol = 20:1;

[0144] In terms of mass ratio, precious metal: carrier = 0.1%;

[0145] Step 3: Immerse the carrier particles in the precious metal precursor solution, ultrasonically vibrate at 30° C. for 2 hours, dry at 120° C. for 2 hours, and calcine at 500° C. for 4 hours in an air atmosphere to obtain a precious metal isomerization dewaxing catalyst.

[0146] Comparative Example 2

[0147] This comparative example provides a noble metal isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0148] Step 1: Weigh 100g ZSM-48 molecular sieve, 50g alumina, 7.69g 65wt% nitric acid, 42.31g deionized water, 4.76g sesbania powder, 0.24g titanium dioxide, and 37.69g deionized water, mix well, knead and extrude into strips to form carrier particles;

[0149] The mass ratio of each component in the carrier is: molecular sieve: alumina: acid solution: binder: deionized water = 1:0.5:0.5:0.05:0.8;

[0150] In terms of mass ratio, sesbania powder: titanium dioxide = 19.83:1;

[0151] Step 2: Dissolve 0.63 g of chloroplatinic acid in 60 g of deionized water and mix at 50° C. for 2 hours to prepare a noble metal precursor solution;

[0152] Step 3: Immerse the carrier particles in a precious metal precursor solution, with a mass ratio of precious metal: carrier = 0.3%, ultrasonically shake at 40°C for 4 hours, dry at 120°C for 2 hours, and calcine at 500°C in an air atmosphere for 4 hours to obtain a precious metal isomerization dewaxing catalyst.

[0153] Comparative Example 3

[0154] This comparative example provides a noble metal isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0155] Step 1: Weigh 100g ZSM-48 molecular sieve, 20g pseudo-boehmite, 9.23g 65wt% nitric acid, 50.77g deionized water, 4.55g sesbania powder, 0.45g titanium dioxide, and 49.23g deionized water, mix well, knead and extrude into strips to form carrier particles;

[0156] The mass ratio of each component in the carrier is: molecular sieve: alumina: acid solution: binder: deionized water = 1:0.2:0.6:0.05:1;

[0157] In terms of mass ratio, sesbania powder: titanium dioxide = 10.11:1;

[0158] Step 2: Dissolve 0.21 g of chloroplatinic acid (409.818) in a mixed solution of 57.14 g of deionized water, 2.86 g of ethanol, and 1.77 g of citric acid (192.12), mix at 50° C. for 2 hours, and prepare a noble metal precursor solution;

[0159] In the noble metal precursor solution:

[0160] In terms of mass ratio, water: alcohol = 20:1;

[0161] In terms of atomic molar ratio, ligand: noble metal = 18:1;

[0162] In terms of mass ratio, precious metal: carrier particles = 0.1%;

[0163] Step 3: Immerse the carrier particles in the precious metal precursor solution, ultrasonically vibrate at 30° C. for 2 hours, dry at 120° C. for 2 hours, and calcine at 500° C. for 4 hours in an air atmosphere to obtain the precious metal isomerization dewaxing catalyst.

[0164] Comparative Example 4

[0165] This comparative example provides a noble metal isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0166] Step 1: Weigh 100g ZSM-22 molecular sieve, 50g alumina, 3.69g 65wt% nitric acid, 36.31g deionized water, 6.77g sesbania powder, 0.23g titanium dioxide, and 13.69g deionized water, mix well, knead and extrude into strips to form carrier particles;

[0167] The mass ratio of each component in the carrier is: molecular sieve: alumina: acid solution: binder: deionized water = 1:0.5:0.4:0.07:0.5;

[0168] In terms of mass ratio, sesbania powder: titanium dioxide = 29.43:1;

[0169] Step 2: Dissolve 0.21 g of chloroplatinic acid (409.818) in a mixed solution of 57.14 g of deionized water, 2.86 g of ethanol, and 0.83 g of oxalic acid (90.03), mix at 50° C. for 2 hours, and prepare a noble metal precursor solution;

[0170] In the noble metal precursor solution:

[0171] In terms of mass ratio, water: alcohol = 20:1;

[0172] In terms of atomic molar ratio, ligand: noble metal = 18:1;

[0173] In terms of mass ratio, precious metal: carrier particles = 0.1%;

[0174] Step 3: Immerse the carrier particles in the precious metal precursor solution, ultrasonically vibrate at 30° C. for 2 hours, dry at 120° C. for 2 hours, and calcine at 500° C. for 4 hours in an air atmosphere to obtain the precious metal isomerization dewaxing catalyst.

[0175] Characterization Test Example 1

[0176] In this characterization test example, the precious metal isomerization dewaxing catalysts provided in Examples 2 to 4 and Comparative Examples 1 to 4 were subjected to STEM tests, and the obtained STEM images were as follows: Figure 1-Figure 7 shown. Figure 1-Figure 3 The small bright spots in the graph are precious metal (platinum or palladium) particles, indicating that the precious metal particles in the precious metal isomerization dewaxing catalysts provided in Examples 2 to 4 of the present invention are small and well dispersed. Figure 1-Figure 3 It can be reasonably expected that in the precious metal isomerization dewaxing catalysts provided in Examples 1 and 5 of the present invention, the precious metal particles are also smaller and better dispersed. Figure 4-Figure 7 In the figure, the bright spots are also precious metal particles, and the bright spots are relatively large, indicating that in the precious metal isomerize dewaxing catalysts provided in Comparative Examples 1 to 4, the precious metal particles have relatively large aggregate clusters and poor dispersion. This indicates that when preparing the precious metal isomerize dewaxing catalyst, no ligand is used, and other ligands, such as ligands containing multiple hydroxyl groups, are used. It is impossible to produce a precious metal isomerize dewaxing catalyst with small precious metal particles and highly dispersed precious metal particles.

[0177] Catalyst Performance Evaluation Example

[0178] This evaluation example uses hydrocracking tail oil as raw material, at reaction temperatures of 340°C and 360°C, reaction pressure of 15 MPa, hydrogen-to-oil ratio of 600:1 and volume space velocity of 1.5 h -1 Under the reaction conditions, the micro-reaction performance of the precious metal isomerization dewaxing catalyst provided in Example 1 was evaluated.

[0179] The parameters of the hydrocracking tail oil feedstock are shown in Table 1 below.

[0180] Table 1

[0181]

[0182] The evaluation results obtained in this evaluation example are shown in Table 2 below.

[0183] Table 2

[0184]

[0185]

[0186] It can be seen from Table 2 above that, compared with the precious metal isomerization dewaxing catalysts provided in Comparative Examples 1 and 4, the precious metal particles of the precious metal isomerization dewaxing catalysts provided in Examples 1 and 4 of the present invention are smaller and better dispersed, and their dehydrogenation activity is significantly improved. Under the same reaction temperature conditions, they can reduce the freezing point of the whole fraction, increase the total base oil yield, increase the heavy base oil yield, and significantly improve the viscosity index, pour point, cloud point, etc. of the heavy base oil.

[0187] 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 highly dispersed noble metal isomerization dewaxing catalyst, characterized in that: The preparation method comprises: Step 1: dissolving the noble metal precursor in a mixture of water, alcohol and ligand, and mixing them evenly to obtain a noble metal precursor solution; wherein the mass ratio of water to alcohol is 20-1:1, and the molar ratio of ligand to noble metal atom is 6-18:1; Step 2: Immerse the carrier particles in a precious metal precursor solution, and obtain the highly dispersed precious metal isomerization dewaxing catalyst by ultrasonic vibration, drying and calcining in air atmosphere; wherein, based on the total weight of the carrier particles as 100%, the amount of precious metal used by atomic mass is 0.1-0.6%.

2. The preparation method according to claim 1, characterized in that: The noble metal precursor is a noble metal salt, and the noble metal salt includes one or a combination of chloroplatinic acid, tetraammine platinum nitrate, platinum nitrate, palladium nitrate, palladium chloride, nickel chloride, and nickel nitrate.

3. The preparation method according to claim 1 or 2, characterized in that: The alcohol includes one or a combination of ethanol, propanol, isopropanol and glycerol.

4. The preparation method according to claim 1 or 2, characterized in that: The ligand includes a ligand containing a carboxyl group or a carbonyl group.

5. The preparation method according to claim 4, characterized in that: The ligand includes one or a combination of sorbic acid, salicylic acid, nicotinamide and lactic acid.

6. The preparation method according to claim 1 or 2, characterized in that: The uniform mixing is performed at 30-60° C. for 2-6 hours.

7. The preparation method according to claim 1 or 2, characterized in that: The ultrasonic oscillation is performed at 30-60° C. for 2-6 hours.

8. The preparation method according to claim 1 or 2, characterized in that: The carrier particles are obtained by uniformly mixing molecular sieve, alumina, acid solution, binder and deionized water and then kneading and extruding them into strips; The mass ratio of molecular sieve, alumina, acid solution, adhesive and deionized water is 1:0.2-0.6:0.3-0.6:0.01-0.1:0.3-1.

9. The preparation method according to claim 8, characterized in that: The molecular sieve includes one or a combination of SAPO-11, SAPO-31, ZSM-12, ZSM-22, ZSM-23, and ZSM-48.

10. The preparation method according to claim 8, characterized in that: The acid solution includes a nitric acid or phosphoric acid solution with a mass concentration of 5-10wt%.

11. The preparation method according to claim 8, characterized in that: The adhesive comprises one or a combination of sesbania powder, titanium dioxide and methyl cellulose.

12. The preparation method according to claim 11, characterized in that: When the binder comprises sesbania powder and titanium dioxide or methyl cellulose and titanium dioxide, the mass ratio of sesbania powder or methyl cellulose to titanium dioxide is 10-30:

1.

13. The preparation method according to claim 1 or 2, characterized in that: The calcination temperature is 450-600° C. and the calcination time is 4-6 hours.

14. A highly dispersed noble metal isomerization dewaxing catalyst, characterized in that: The highly dispersed precious metal isomerization dewaxing catalyst is prepared by the preparation method of the highly dispersed precious metal isomerization dewaxing catalyst according to any one of claims 1 to 13, wherein the precious metal is fully dispersed on the surface of the carrier particles and the internal pores thereof, and the precious metal content calculated by atomic mass is 0.1-0.6% based on the total weight of the carrier particles as 100%.

15. Use of the highly dispersed noble metal isomerization dewaxing catalyst according to claim 14 in preparing lubricating oil base oil by catalytic isomerization dewaxing reaction.

16. A method for preparing lubricating oil base oil by isomerization dewaxing, characterized in that: The catalyst used in the method is the highly dispersed precious metal isomerization dewaxing catalyst as described in claim 14.

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