A multi-level pore alumina material, a preparation method and application thereof

Abstract

This invention discloses a hierarchical porous alumina material, its preparation method, and its application. The alumina material has a spherical core-shell structure, with mesoporous alumina as the core and macroporous alumina as the shell. The pore size distribution of the alumina material exhibits hierarchical pore distribution characteristics, wherein the pore volume of 6-15 nm pores accounts for 20% to 50% of the total pore volume, and the pore volume of pores larger than 20 nm accounts for not less than 40% of the total pore volume. The preparation method of the hierarchical porous alumina material includes the following steps: (1) calcining boehmite to obtain alumina particles; (2) mixing and dispersing surfactant, hydrocarbon-containing compound, and alumina particles evenly to obtain a first feed stream; (3) mixing aluminum sol, emulsifier, curing agent, and additives evenly to obtain a second feed stream; (4) mixing the first and second feed streams, and then further molding, aging, extraction, washing, drying, and calcining to obtain an alumina composite material. The alumina material of this invention is suitable as a carrier for preparing heavy oil hydrogenation catalysts with hierarchical pores and acidic distribution, and can be further used in heavy oil hydrogenation processes.

Description

Technical Field

[0001] This invention belongs to the field of inorganic materials technology, and relates to alumina and its preparation and application, particularly to a hierarchical porous alumina and its preparation and application. Background Technology

[0002] Currently, my country's crude oil processing volume is approximately 670 million tons per year, of which 30-40% is heavy residue oil that is difficult to process and utilize. my country's dependence on foreign oil has exceeded 70%. How to efficiently convert and utilize this portion of heavy residue oil resources is the key to solving this problem.

[0003] Residue hydrotreating is a key technology for the efficient conversion of residue oil. It not only removes impurities but also produces high-value-added light distillate products. Based on the type of reactor, residue hydrotreating can be divided into three types: fixed-bed, fluidized-bed, and suspended-bed. Among them, fixed-bed residue hydrotreating technology is relatively mature, with low investment and operating costs, and safe and simple operation, making it widely used. Fluidized-bed residue hydrotreating technology has the ability to process high-sulfur, high-carbon, and high-metal heavy crude oil, and has advantages such as uniform temperature within the reactor, long operating cycles, and flexible operation. It has experienced rapid development since 2000. Currently, these two technologies are the mainstream technologies for industrial application of residue hydrotreating.

[0004] Residue oil contains a large amount of impurities such as metals, sulfur, and nitrogen, and these impurities are mostly concentrated in heavy components such as gums and asphaltenes. Therefore, the challenge of residue oil hydrotreating is how to achieve efficient asphaltenes conversion and improve the impurity removal reaction effect. Residue oil hydrotreating typically employs catalyst gradation for asphaltenes conversion and impurity removal reactions to improve product quality and meet the requirements of subsequent processes. However, catalyst gradation is a complex process, requiring the blending of multiple catalysts. How to realize the catalyst gradation concept on a single catalyst has been a continuous research direction.

[0005] CN201410540168.1 discloses a method for catalyst gradation in residue oil hydrotreating and a method for residue oil hydrotreating. The catalyst gradation method involves sequentially loading a hydrotreating protection catalyst, a hydrodemetallization catalyst, a hydrodesulfurization catalyst, and a hydrocarbon removal catalyst along the flow direction in a residue oil hydrotreating device. The total acid content of each catalyst gradually increases along the flow direction, the proportion of Lewis acid gradually decreases, and the proportion of Bronsted acid gradually increases. This patent achieves directional impurity removal from residue oil through macroscopic catalyst gradation, which is relatively cumbersome.

[0006] CN201010509320.1 discloses a method for hydrotreating heavy feedstock oil using a fluidized bed reactor. This patent uses a fluidized bed hydrotreating reactor where heavy feedstock oil and hydrogen enter from the bottom and react under hydrotreating conditions. The reacted material is discharged from the top of the reactor. The fluidized bed hydrotreating reactor uses a mixed catalyst of at least two catalysts. This patent achieves macroscopically different pore structures and activity distributions by employing two catalysts. However, the backmixing characteristic of the fluidized bed reactor prevents the full utilization of the advantages of both catalysts. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a hierarchical porous alumina material, its preparation method, and its applications. The hierarchical porous alumina material has a spherical core-shell structure, with mesoporous alumina as the core and macroporous alumina as the shell, achieving a macroscopic and microscopic stepped pore structure on a single alumina material. It is particularly suitable as a carrier for preparing heavy oil hydrogenation catalysts with stepped pores and acidic distribution, and can be further used in the gradual reaction heavy oil hydrogenation process.

[0008] To achieve the above-mentioned objectives, the first aspect of the present invention provides a multi-level porous alumina material, wherein the alumina material has a spherical core-shell structure, with mesoporous alumina as the core and macroporous alumina as the shell; based on the weight of the alumina material, the content of mesoporous alumina in the core is 20wt% to 60wt%, and the content of macroporous alumina in the shell is 40wt% to 80wt%.

[0009] Furthermore, in the above-mentioned hierarchical porous alumina material, the pore size distribution of the alumina material has the characteristics of hierarchical pore distribution, wherein the pore volume of 6-15nm accounts for 30% to 60% of the total pore volume, and the pore volume of pores larger than 20nm accounts for not less than 30% of the total pore volume.

[0010] Furthermore, in the above-mentioned hierarchical porous alumina materials, the pore volume of 6-15nm pores in the core porous alumina accounts for 40% to 70% of the total pore volume, while the pore volume of pores larger than 20nm accounts for less than 20% of the total pore volume.

[0011] Furthermore, in the above-mentioned hierarchical porous alumina materials, the pore volume of the macroporous alumina with pores larger than 20 nm accounts for more than 50% of the total pore volume.

[0012] Furthermore, in the aforementioned hierarchical porous alumina materials, the specific surface area of ​​the alumina material is 100–280 m². 2 / g, preferably 120-250m 2 / g

[0013] Furthermore, in the above-mentioned hierarchical porous alumina material, the pore volume of the alumina material is 0.50 to 0.80 mL / g, preferably 0.55 to 0.75 mL / g.

[0014] Furthermore, in the above-mentioned multi-level porous alumina material, the particle diameter of the alumina material is 0.8 to 2.0 mm, preferably 1.0 to 2.0 mm.

[0015] Furthermore, in the above-mentioned multi-level porous alumina material, the wear index of the alumina material is not greater than 0.05%, preferably not greater than 0.03%.

[0016] Furthermore, in the above-mentioned multi-level porous alumina material, the lateral compressive strength of the alumina material is greater than 15 N / mm, preferably greater than 20 N / mm.

[0017] A second aspect of this invention provides a method for preparing a hierarchical porous alumina material, comprising the following steps:

[0018] (1) The pseudoboehmite was roasted and then ground to obtain alumina particles;

[0019] (2) Mix the surfactant, hydrocarbon compound, and alumina particles obtained in step (1), and disperse them evenly to obtain the first material flow;

[0020] (3) Mix aluminum sol, emulsifier, curing agent and additives, and mix evenly to obtain the second material stream;

[0021] (4) The first material stream obtained in step (2) and the second material stream obtained in step (3) are mixed and mixed evenly to obtain an oil-in-water emulsion. Then, the emulsion is further processed by molding, aging, extraction, washing, drying and calcination to obtain an alumina composite material.

[0022] Furthermore, in the above-mentioned method for preparing hierarchical porous alumina material, the calcination temperature in step (1) is 450℃~750℃, preferably 500℃~700℃, and the calcination time is 1~6h, preferably 2~5h. The properties of the calcined alumina are as follows: specific surface area is 250~350m². 2 / g, pore volume is 0.50~1.0mL / g, and pore size is 8~12nm.

[0023] Furthermore, in the above-mentioned method for preparing multi-level porous alumina material, the alumina particles obtained after calcination and grinding in step (1) have a particle size of 2 to 10 micrometers, preferably 3 to 8 micrometers.

[0024] Furthermore, in the above-mentioned method for preparing hierarchical porous alumina material, the hydrophilic-lipophilic balance (HLB) value of the surfactant mentioned in step (2) is 16 to 18, specifically at least one of Tween 20, Pinetarsol O-25, and Pinetarsol O-30. The amount of surfactant added is 5.0% to 15.0% of the mass of the alumina particles in step (1), preferably 5.0% to 13.0%.

[0025] Furthermore, in the above-mentioned method for preparing hierarchical porous alumina materials, the kinematic viscosity of the hydrocarbon-containing compound at 40°C in step (2) is 20–40 mm. 2 / s, preferably 25-35mm 2 / s; the hydrocarbon compound may be selected from at least one of white oil, diesel oil, kerosene, lubricating oil, C10-C15 alkane compounds, etc.; preferably white oil and / or diesel oil. The amount of the hydrocarbon compound added is 1.0 to 3.0 times the weight of the alumina particles obtained after calcination and grinding in step (1), preferably 1.5 to 2.5 times.

[0026] Furthermore, in the above-mentioned method for preparing multi-level porous alumina material, the solid content of the first material stream obtained after uniform dispersion in step (2) is 25wt% to 40wt%, preferably 27wt% to 35wt%.

[0027] Furthermore, in the above-mentioned method for preparing hierarchical porous alumina materials, the alumina mass content in the alumina sol in step (3) is 20% to 45%, preferably 25% to 40%. The alumina sol can be a commercially available product or can be prepared using existing methods, such as reacting aluminum with hydrochloric acid solution, reacting aluminum with aluminum chloride solution, or reacting boehmite prepared by the aluminum alkoxide method with nitric acid solution.

[0028] Furthermore, in the above-mentioned method for preparing multi-level porous alumina material, the curing agent in step (3) is one or more of hexamethylenetetramine and urea, preferably hexamethylenetetramine; the mass concentration of the curing agent is 30% to 70%; the amount of the curing agent added is 1% to 15% of the mass of alumina in the alumina sol, preferably 2.5% to 12%.

[0029] Furthermore, in the above-mentioned method for preparing hierarchical porous alumina material, the emulsifier in step (3) is a nonionic emulsifier with a hydrophilic-lipophilic balance (HLB) of 10 to 15.8. The emulsifier is at least one of polyoxyethylene sorbitan fatty acid ester, fatty alcohol polyoxyethylene ether, etc. Specifically, the emulsifier can be selected from at least one of Tween 40, Tween 60, Tween 80, AEO-7, AEO-9, and AEO-15. The concentration of the emulsifier is 0.5wt% to 2.5wt%, and the amount of emulsifier added is 0.2wt% to 2.0wt% of the mass of alumina in the alumina sol, preferably 0.5wt% to 1.5wt%.

[0030] Furthermore, in the above-mentioned method for preparing multi-level porous alumina material, the additive in step (3) is selected from one or more of methacryloyloxyethyltrimethylammonium chloride (DMC), dimethyl diallyl ammonium chloride (DMDAAC), acryloyloxyethyltrimethylammonium chloride (DAC), and polyacrylamide, preferably polyacrylamide; the concentration of the additive is 1wt% to 5wt%, and the amount of additive added is 1wt% to 10wt% of the mass of alumina in the alumina sol.

[0031] Furthermore, in the above-mentioned method for preparing multi-level porous alumina materials, the amount of alumina particles added is 0.25 to 1.25 times the weight of alumina in the alumina sol.

[0032] Furthermore, in the above-mentioned method for preparing multi-level porous alumina materials, the solid content of the water-in-oil emulsion in step (4) is 15wt% to 20wt%.

[0033] Furthermore, in the above-mentioned method for preparing multi-level porous alumina materials, the molding in step (4) adopts an oil column molding method, in which the water-in-oil emulsion in step (4) is dripped into the oil column. The oil phase medium used in the oil injection molding process is either white oil or diesel oil, preferably white oil, and the kinematic viscosity of the white oil at 40°C is 20-40 mm. 2 / s, preferably 25-35mm 2 / s; the molding temperature is 90℃~110℃, preferably 95℃~105℃. The inner diameter of the dripper used is 0.4mm~2.0mm.

[0034] Furthermore, in the above-mentioned method for preparing multi-level porous alumina materials, the aging process in step (4) has a temperature of 130℃~180℃, a pressure of 0.2~0.5MPa, and an aging time of 2~6h.

[0035] Furthermore, in the above-mentioned method for preparing multi-level porous alumina materials, the washing in step (4) includes two steps. The first step of washing mainly removes the medium oil on the molding material. The solvent can be one or more of petroleum ether, cyclohexane, toluene, and anhydrous ethanol, preferably a mixed solution of at least one of petroleum ether, cyclohexane, and toluene with anhydrous ethanol. More specifically, the volume ratio of anhydrous ethanol in the mixed solution is 25% to 50%. The second step of washing is washing with deionized water at 70°C to 90°C.

[0036] Furthermore, in the above-mentioned method for preparing multi-level porous alumina material, the drying temperature in step (4) is 100℃~150℃ and the drying time is 6~10 hours; the calcination temperature is 750℃~950℃ and the calcination time is 1~4 hours.

[0037] A third aspect of the present invention provides a hierarchical porous alumina material obtained by the above preparation method.

[0038] The fourth aspect of the present invention provides a heavy oil hydrogenation catalyst, wherein the catalyst uses the above-mentioned hierarchical porous alumina material as a support.

[0039] Furthermore, in the above-mentioned heavy oil hydrogenation catalyst, the active component is a Group VIII metal and / or a Group VIB metal, and based on the weight of the catalyst, the support content is 73% to 95%, preferably 80% to 95%; the content of the Group VIII metal as oxide is 0.5% to 5%, preferably 1% to 4%; and the content of the Group VIB metal as oxide is 4.0% to 20%, preferably 4% to 15%.

[0040] Furthermore, in the above-mentioned heavy oil hydrogenation catalyst, the active metal component can be introduced onto the support using any method existing in the art, and those skilled in the art can choose according to actual needs. For example, if a conventional impregnation method is used for loading, firstly, a metal salt containing the active metal component is prepared into an impregnation solution, then the support is contacted with the impregnation solution, and finally, the catalyst is obtained after separation, washing, drying, and calcination. Generally, the drying temperature is 100℃~150℃, and the drying time is 2~24h; the calcination temperature is 400℃~600℃, and the calcination time is 2~8h.

[0041] Compared with the prior art, the advantages of the hierarchical porous alumina material and its preparation method provided by the present invention are mainly reflected in the following aspects:

[0042] 1. The multi-level porous alumina of the present invention can flexibly adjust the pore structure of the core alumina according to the needs. By adjusting the properties of the pseudoboehmite raw material and the calcination conditions, alumina with different pore structures can be obtained.

[0043] 2. In the method for preparing multi-level porous alumina material of the present invention, the surface wetting and dispersion performance of alumina is improved by using a dispersant and combined with ultrasonic treatment, ensuring that it can be uniformly dispersed in the alumina sol and ensuring the stability of the dispersion system. This solves the problem that the surface energy of the alumina particles obtained by calcination is high and the dispersion is poor, making it impossible to prepare core-shell structured alumina.

[0044] 3. In the preparation method of multi-level porous alumina material of the present invention, aluminum sol is made into an oil-in-water (O / W) emulsion. During droplet forming, the emulsion droplets enter the medium oil and automatically shrink into a spherical shape with a water film on the outer surface and an emulsion inside due to surface tension. The stability of the emulsion is destroyed due to changes in temperature and pH value. The calcined alumina is in a free state in the aluminum sol solution. Under the action of the additives, physical and chemical changes occur. Through adsorption, bridging, cross-linking, and neutralization of the charge on the surface of the suspended matter, the particles change from repulsion to attraction, thereby forming agglomerated alumina after calcination, which becomes the core structure. At the same time, the curing agent in the emulsion decomposes when heated, and the released alkaline gas causes the aluminum sol that encapsulates the core structure to form gel spheres, thereby forming a core-shell structure of spherical alumina.

[0045] 4. In the method for preparing multi-level porous alumina material of the present invention, the aging treatment with relatively high temperature and high pressure after molding can further increase the pores of the alumina material shell, realize the stepwise pore structure at the macroscopic level of the spherical alumina material, and at the same time extract the aged material to recover the organic matter therein, prevent environmental pollution, and also avoid the problem of reduced strength caused by the decomposition of organic matter during the calcination process.

[0046] 5. In the method for preparing multi-level porous alumina materials of the present invention, catalysts with different pore size distributions and active metal distributions can be prepared from both macroscopic and microscopic perspectives, achieving a combination of multiple catalyst properties on one catalyst, which is more conducive to the gradual hydrogenation reaction of heavy oil and improves the activity, stability and utilization rate of the catalyst. Detailed Implementation

[0047] The following examples further illustrate the effects of the present invention. These examples are implemented based on the technical solution of the present invention's method for preparing multi-level porous alumina-alumina core-shell structured spherical carriers, and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following examples.

[0048] Unless otherwise specified, the experimental methods used in the following examples are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following examples were purchased from conventional biochemical reagent stores.

[0049] The analytical methods of this invention are as follows: specific surface area, pore volume, external specific surface area, and pore distribution were measured using the cryogenic liquid nitrogen physical adsorption method; the instruments used were ASAP2405 and 2420 physical adsorption instruments manufactured by a US company; the wear index was measured using the drum method with a KM-ZV wear meter; the metal composition was measured using inorganic spectrophotometry; and the lateral compressive strength was measured using a ZQJ-II intelligent particle strength testing machine.

[0050] The technical features of the present invention are further described below through embodiments, but are not limited to these embodiments.

[0051] Example 1

[0052] 40g with a specific surface area of ​​261m² 2 Calcined alumina with a pore volume of 0.70 mL / g and a pore size of 10 nm was ground into powder with a particle size of 4.5 μm using a ball mill.

[0053] Add 4g of Pingpingjia O-25 to a solution with a kinematic viscosity of 28mm at 40℃. 2 The powder was added to 80g of white oil per s after stirring evenly, and then stirred under 100KHZ ultrasonic waves to obtain a uniformly dispersed system with a solid content of 32.25wt%.

[0054] Weigh 240g of aluminum sol with an Al2O3 content of 25% prepared by reacting aluminum with hydrochloric acid solution, add 10g of hexamethylenetetramine solution with a concentration of 36wt%, 60g of Tween 60 with an HLB value of 14.9, and 100g of polyacrylamide with a concentration of 2wt%, and stir to mix evenly to obtain aluminum sol mixture.

[0055] The above dispersion system was added to the aluminum sol mixture and mixed under a high shear device at a speed of 15,000 rpm to obtain an oil-in-water emulsion with a solid content of 18.7 wt%.

[0056] Using a dropper with an inner diameter of 0.8 mm, apply the solution to a fluid with a viscosity of 30 mm at 40°C. 2 The above-mentioned oil-in-water (O / W) emulsion was added dropwise to white oil at 97℃ to form the gel microspheres. After forming, the gel microspheres were aged in a small autoclave at 140℃ and 0.3MPa for 3 hours. After aging, the gel microspheres were first washed with a 1:1 mixture of petroleum ether and anhydrous ethanol to remove the medium oil from the formed material, then washed with deionized water at 85℃, dried at 130℃ for 8 hours, and calcined at 800℃ for 3 hours to obtain alumina carrier A-1. The analytical results are shown in Table 1.

[0057] Weigh 28.0 g of phosphoric acid and add 450 mL of distilled water. Then, add 98.88 g of molybdenum oxide and 41.83 g of basic nickel carbonate sequentially. Heat and stir until completely dissolved. Then, dilute the solution to 500 mL with distilled water to obtain solution L-1. Saturate the support A-1 with solution L-1, dry it at 110 °C for 2 h, and calcine it at 450 °C for 5 h to obtain catalyst CA-1. Its properties are shown in Table 2.

[0058] Example 2

[0059] The process was basically the same as in Example 1, except that Pingpingjia O-25 was replaced with Tween 20 (HLB value 16.7), hexamethylenetetramine was replaced with urea, and the aging conditions were adjusted to 150°C and 0.4MPa for 2 hours to prepare alumina carrier A-2. The analytical results are shown in Table 2.

[0060] The support A-2 was saturated with solution L-1, dried at 110℃ for 2 h, and calcined at 480℃ for 3 h to obtain catalyst CA-2, the properties of which are shown in Table 2.

[0061] Example 3

[0062] The method is basically the same as in Example 1, except that the specific surface area of ​​the calcined alumina is adjusted to be 300 m² / g. 2 Alumina support A-3 was obtained by grinding a powder with a pore volume of 0.95 mL / g and a pore size of 11 nm to a particle size of 3.5 μm using a ball mill. The aging conditions were 130℃ and 0.5 MPa for 6 h, and the calcination temperature of the support was adjusted to 750℃ for 3 h. The analysis results are shown in Table 1.

[0063] The support A-3 was saturated with solution L-1, dried at 120℃ for 2 h, and calcined at 520℃ for 3 h to obtain catalyst CA-3, the properties of which are shown in Table 2.

[0064] Example 4

[0065] 30g with a specific surface area of ​​300m² 2 Calcined alumina with a pore volume of 0.95 mL / g and a pore size of 11 nm was ground into powder with a particle size of 3.5 μm using a ball mill.

[0066] Add 3.6g of Pingpingjia O-30 to a solution with a kinematic viscosity of 30mm at 40℃. 2 In 70g of white oil per second, after stirring evenly, the above-ground powder was added, and then stirred under 100KHZ ultrasonication to obtain a uniformly dispersed system with a solid content of 28.95wt%.

[0067] Weigh 234g of aluminum sol with an Al2O3 content of 30% prepared by reacting aluminum with hydrochloric acid solution, add 17.5g of hexamethylenetetramine solution with a concentration of 40wt%, 52.5g of Tween 80 solution with a concentration of 2.0wt% and 117g of methacryloxyethyltrimethylammonium chloride (DMC) with a concentration of 3wt% and an HLB value of 15.0, and stir to mix evenly to obtain an aluminum sol mixture.

[0068] The above dispersion system was added to the aluminum sol mixture and mixed under a high shear device at a speed of 15,000 rpm to obtain an oil-in-water emulsion with a solid content of 19.1 wt%.

[0069] Using a dropper with an inner diameter of 0.8 mm, a solution of 35 mm viscosity was applied at 40°C. 2 The above-mentioned oil-in-water (O / W) emulsion was added dropwise to white oil at 100℃ to form the gel microspheres. After forming, the gel microspheres were aged in a small autoclave at 150℃ and 0.5MPa for 2 hours. After aging, the gel microspheres were first washed with a 1:1 mixture of petroleum ether and anhydrous ethanol to remove the medium oil from the formed material, then washed with deionized water at 85℃, dried at 130℃ for 8 hours, and calcined at 850℃ for 3 hours to obtain the alumina carrier A-4 of this invention. The analytical results are shown in Table 1.

[0070] Weigh 26.81 g of phosphoric acid and add 450 mL of distilled water. Then, add 72.81 g of molybdenum oxide and 30.70 g of basic nickel carbonate sequentially. Heat and stir until completely dissolved. Dilute the solution to 500 mL with distilled water to obtain solution L-2. Saturate impregnate support A-4 with solution L-2, dry at 120 °C for 2 h, and calcine at 480 °C for 5 h to obtain catalyst CA-4. Its properties are shown in Table 2.

[0071] Example 5

[0072] This is basically the same as Example 4, except that the calcined alumina is replaced with 261m. 2 Calcined alumina with a pore volume of 0.70 mL / g and a pore size of 10 nm was prepared. 3.6 g of Pingpingjia O-30 was adjusted to 4.0 g of Pingpingjia O-25. 200 g of alumina sol with an Al2O3 content of 35% was added. The aging conditions were adjusted to 140℃ and 0.4 MPa for 6 h. The calcination conditions were then adjusted to 900℃ and calcined for 4 h to obtain alumina support A-5. The analytical results are shown in Table 1.

[0073] Weigh 26.81 g of phosphoric acid and add 450 mL of distilled water. Then, add 72.81 g of molybdenum oxide and 30.70 g of basic nickel carbonate sequentially. Heat and stir until completely dissolved. Dilute the solution to 500 mL with distilled water to obtain solution L-2. Saturate impregnate support A-5 with solution L-2, dry at 120 °C for 2 h, and calcine at 480 °C for 5 h to obtain catalyst CA-5. Its properties are shown in Table 2.

[0074] Comparative Example 1

[0075] 40g with a specific surface area of ​​261m² 2 Calcined alumina with a pore volume of 0.70 mL / g and a pore size of 10 nm was ground into powder with a particle size of 4.5 μm using a ball mill.

[0076] The kinematic viscosity at 0°C is 28 mm. 2The powder was added to 80g of white oil per second and stirred evenly. Then, the powder was stirred under 100KHZ ultrasonication to obtain a uniform dispersion system with a solid content of 33.33wt%.

[0077] Weigh 240g of aluminum sol with an Al2O3 content of 25% prepared by reacting aluminum with hydrochloric acid solution, add 10g of hexamethylenetetramine solution with a concentration of 36wt%, 60g of Tween 60 with an HLB value of 14.9, and 100g of polyacrylamide with a concentration of 2wt%, and stir to mix evenly to obtain aluminum sol mixture.

[0078] The above dispersion system was added to the aluminum sol mixture and mixed under a high shear device at a speed of 15,000 rpm to obtain an oil-in-water emulsion with a solid content of 18.7 wt%.

[0079] Using a dropper with an inner diameter of 0.8 mm, apply the solution to a fluid with a viscosity of 30 mm at 40°C. 2 The above-mentioned oil-in-water (O / W) emulsion was added dropwise to white oil at 97°C to form the gel microspheres. After forming, the gel microspheres were aged in a small autoclave at 140°C and 0.3 MPa for 3 hours. After aging, the gel microspheres were first washed with a 1:1 volume ratio of petroleum ether and anhydrous ethanol to remove the medium oil from the formed material, then washed with deionized water at 85°C, dried at 130°C for 8 hours, and calcined at 800°C for 3 hours to obtain the alumina carrier F-1 of this invention. The analytical results are shown in Table 1.

[0080] Weigh 28.00 g of phosphoric acid and add 450 mL of distilled water. Then, add 98.88 g of molybdenum oxide and 41.83 g of basic nickel carbonate sequentially. Heat and stir until completely dissolved. Then, dilute the solution to 500 mL with distilled water to obtain solution L-1. Saturate the support F-1 with solution L-1, dry it at 110 °C for 2 h, and calcine it at 450 °C for 5 h to obtain catalyst CF-1. Its properties are shown in Table 2.

[0081] Comparative Example 2

[0082] 40g with a specific surface area of ​​261m² 2 Calcined alumina with a pore volume of 0.70 mL / g and a pore size of 10 nm was ground into powder with a particle size of 4.5 μm using a ball mill.

[0083] Add 4g of Pingpingjia O-25 to a solution with a kinematic viscosity of 28mm at 40℃. 2 The powder was added to 80g of white oil per s after stirring evenly, and then stirred under 100KHZ ultrasonic waves to obtain a uniformly dispersed system with a solid content of 32.25wt%.

[0084] Weigh 240g of aluminum sol with an Al2O3 content of 25% prepared by reacting aluminum with hydrochloric acid solution, add 10g of hexamethylenetetramine solution with a concentration of 36wt%, HLB value of 14.9 and 60g of Tween 60 with a concentration of 1.0wt%, and stir to mix evenly to obtain aluminum sol mixture.

[0085] The above dispersion system was added to the aluminum sol mixture and mixed under a high shear device at a speed of 15,000 rpm to obtain an oil-in-water emulsion with a solid content of 18.7 wt%.

[0086] Using a dropper with an inner diameter of 0.8 mm, apply the solution to a fluid with a viscosity of 30 mm at 40°C. 2 The above-mentioned oil-in-water (O / W) emulsion was added dropwise to white oil at 97℃ to form the gel microspheres. After forming, the gel microspheres were aged in a small autoclave at 140℃ and 0.3MPa for 3 hours. After aging, the gel microspheres were first washed with a 1:1 volume ratio of petroleum ether and anhydrous ethanol to remove the medium oil from the formed material, then washed with deionized water at 85℃, dried at 130℃ for 8 hours, and calcined at 800℃ for 3 hours to obtain alumina carrier F-2. The analytical results are shown in Table 1.

[0087] Weigh 28.00 g of phosphoric acid and add 450 mL of distilled water. Then, add 98.88 g of molybdenum oxide and 41.83 g of basic nickel carbonate sequentially. Heat and stir until completely dissolved. Dilute the solution to 500 mL with distilled water to obtain solution L-1. Saturate the support F-2 with solution L-1, dry at 110 °C for 2 h, and calcine at 450 °C for 5 h to obtain catalyst CF-2. Its properties are shown in Table 2.

[0088] The physicochemical properties of the supports and catalysts obtained above are listed in Table 1 and Table 2, respectively.

[0089] Table 1. Carrier Properties

[0090]

[0091] Table 2 Catalyst Properties

[0092]

[0093] The data in the table show that the spherical carrier prepared by this invention has a more concentrated pore size of 6-15 nm, and a larger proportion of pores >20 nm, which is beneficial for the hydrogenation reaction of residual oil. At the same time, the prepared microsphere carrier has high mechanical properties and good wear resistance, making it suitable for the fluidized bed heavy oil hydrogenation process.

[0094] The catalysts prepared in Table 2 were evaluated for activity on the CSTR unit. The properties of the feedstock oil used are shown in Table 3, and the evaluation conditions are shown in Table 4. Samples of the production oil were taken and analyzed after 1000 hours of operation. The activity of the comparative example C-F1 was set as 100. Other evaluation results compared with the activity of the comparative example C-F1 are shown in Table 5.

[0095] Table 3 Properties of Feed Oil

[0096]

[0097] Table 4 Evaluation Criteria

[0098]

[0099] Table 5 Evaluation Results

[0100]

[0101] The generated oils from C-A1, C-F1, and C-F2 after 2000 hours of operation were analyzed. The activity of the comparative example C-F1 was set at 100. The evaluation results of the other oils compared with the activity of the comparative example C-F1 are shown in Table 6.

[0102] Table 6 Comparison of 2000h operation results

[0103]

[0104] The data in the table show that the catalyst prepared by this invention has better hydrogenation activity. Using the catalyst prepared by this invention, the step-by-step conversion of heavy oil can be achieved, and the operating cycle of the unit can be extended.

Claims

1. A hierarchical porous alumina material, wherein the alumina material has a spherical core-shell structure, with mesoporous alumina as the core and macroporous alumina as the shell; based on the weight of the alumina material, the content of mesoporous alumina in the core is 20wt% to 60wt%, and the content of macroporous alumina in the shell is 40wt% to 80wt%; the pore volume of 6-15nm pores in the core mesoporous alumina accounts for 40% to 70% of the total pore volume, and the pore volume of pores larger than 20nm accounts for less than 20% of the total pore volume; the pore volume of pores larger than 20nm in the shell macroporous alumina accounts for more than 50% of the total pore volume; the pore size distribution of the alumina material has a hierarchical pore distribution characteristic, wherein the pore volume of 6-15nm pores accounts for 30% to 60% of the total pore volume, and the pore volume of pores larger than 20nm accounts for not less than 30% of the total pore volume.

2. The hierarchical porous alumina material according to claim 1, characterized in that: The specific surface area of ​​alumina materials is 100–280 m². 2 / g.

3. The hierarchical porous alumina material according to claim 1, characterized in that: The specific surface area of ​​alumina materials is 120–250 m². 2 / g.

4. The hierarchical porous alumina material according to claim 1, characterized in that: The pore volume of the alumina material is 0.50–0.80 mL / g.

5. The hierarchical porous alumina material according to claim 1, characterized in that: The pore volume of the alumina material is 0.55–0.75 mL / g.

6. The hierarchical porous alumina material according to claim 1, characterized in that: The particle diameter of the alumina material is 0.8–2.0 mm.

7. The hierarchical porous alumina material according to claim 1, characterized in that: The particle diameter of the alumina material is 1.0 to 2.0 mm.

8. The hierarchical porous alumina material according to claim 1, characterized in that: The wear index of alumina materials is no greater than 0.05%.

9. The hierarchical porous alumina material according to claim 1, characterized in that: The wear index of alumina materials is no greater than 0.03%.

10. The hierarchical porous alumina material according to claim 1, characterized in that: The lateral compressive strength of alumina materials is greater than 15 N / mm.

11. The hierarchical porous alumina material according to claim 1, characterized in that: The lateral compressive strength of alumina materials is greater than 20 N / mm.

12. A method for preparing a hierarchical porous alumina material, comprising the following steps: (1) The pseudoboehmite was roasted and then ground to obtain alumina particles; (2) Mix the surfactant, hydrocarbon compound, and alumina particles obtained in step (1), and disperse them evenly to obtain the first material flow; (3) Mix aluminum sol, emulsifier, curing agent and additives, and mix evenly to obtain the second material stream; the additives are selected from one or more of methacryloyloxyethyltrimethylammonium chloride, dimethyl diallyl ammonium chloride, acryloyloxyethyltrimethylammonium chloride and polyacrylamide; (4) The first material stream obtained in step (2) and the second material stream obtained in step (3) are mixed and mixed evenly to obtain an oil-in-water emulsion. Then, the alumina material is obtained by molding, aging, extraction, washing, drying and calcination.

13. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: In step (1), the roasting temperature is 450℃~750℃ and the roasting time is 1~6h.

14. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: In step (1), the roasting temperature is 500℃~700℃ and the roasting time is 2~5h.

15. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The properties of the alumina particles after calcination in step (1) are as follows: specific surface area is 250-350 m². 2 / g, pore volume is 0.50~1.0mL / g, and pore size is 8~12nm.

16. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The alumina particles obtained after calcination and grinding in step (1) have a particle size of 2 to 10 micrometers.

17. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The alumina particles obtained after calcination and grinding in step (1) have a particle size of 3 to 8 micrometers.

18. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The surfactant mentioned in step (2) has a hydrophilic-lipophilic balance value of 16 to 18, and is at least one of Tween 20, Pinto-PineO-25, and Pinto-PineO-30.

19. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The amount of surfactant added in step (2) is 5.0% to 15.0% of the mass of alumina particles in step (1).

20. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The amount of surfactant added in step (2) is 5.0% to 13.0% of the mass of alumina particles in step (1).

21. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The kinematic viscosity of the hydrocarbon compound in step (2) at 40°C is 20–40 mm. 2 / s.

22. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The kinematic viscosity of the hydrocarbon compound in step (2) at 40°C is 25–35 mm. 2 / s.

23. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The hydrocarbon-containing compound is selected from at least one of white oil, diesel oil, kerosene, lubricating oil, and C10-C15 alkane compounds; the amount of the hydrocarbon-containing compound added is 1.0 to 3.0 times the weight of the alumina particles obtained after calcination and grinding in step (1).

24. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The hydrocarbon compound is white oil and / or diesel oil; the amount of the hydrocarbon compound added is 1.5 to 2.5 times the weight of the alumina particles obtained after calcination and grinding in step (1).

25. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: After uniform dispersion in step (2), the solid content of the first material stream is 25wt% to 40wt%.

26. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: After uniform dispersion in step (2), the solid content of the first material stream is 27wt% to 35wt%.

27. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The aluminum sol in step (3) contains 20% to 45% aluminum oxide by mass.

28. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The aluminum sol in step (3) contains 25% to 40% aluminum oxide by mass.

29. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The curing agent in step (3) is one or more of hexamethylenetetramine and urea; the mass concentration of the curing agent is 30% to 70%; the amount of the curing agent added is 1% to 15% of the mass of alumina in the aluminum sol.

30. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The curing agent in step (3) is hexamethylenetetramine; the mass concentration of the curing agent is 30% to 70%; the amount of the curing agent added is 2.5% to 12% of the mass of alumina in the aluminum sol.

31. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The emulsifier in step (3) is a nonionic emulsifier with a hydrophilic-lipophilic balance value of 10 to 15.

8. The emulsifier is at least one of polyoxyethylene sorbitan fatty acid ester and fatty alcohol polyoxyethylene ether.

32. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The emulsifier in step (3) is selected from at least one of Tween 40, Tween 60, Tween 80, AEO-7, AEO-9, and AEO-15.

33. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The concentration of the emulsifier is 0.5wt% to 2.5wt%, and the amount of emulsifier added is 0.2wt% to 2.0wt% of the mass of alumina in the aluminum sol.

34. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The concentration of the emulsifier is 0.5wt% to 2.5wt%, and the amount of emulsifier added is 0.5wt% to 1.5wt% of the mass of alumina in the aluminum sol.

35. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The additive in step (3) is polyacrylamide.

36. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The concentration of the additive is 1wt% to 5wt%, and the amount of the additive added is 1wt% to 10wt% of the mass of alumina in the alumina sol.

37. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The amount of alumina particles added is 0.25 to 1.25 times the weight of alumina in the alumina sol.

38. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The solid content of the oil-in-water emulsion in step (4) is 15wt% to 20wt%.

39. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: In step (4), the molding process uses an oil column molding method. The water-in-oil emulsion from step (4) is dripped into the oil column. The oil phase medium used in the oil injection molding process is either white oil or diesel oil. The kinematic viscosity of white oil at 40°C is 20-40 mm. 2 / s; molding temperature is 90℃~110℃.

40. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: In step (4), the molding process uses an oil column molding method. The water-in-oil emulsion from step (4) is dripped into the oil column. The oil phase medium used in the oil injection molding process is white oil, and the kinematic viscosity of white oil at 40°C is 25-35 mm. 2 / s; molding temperature is 95℃~105℃.

41. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The aging process in step (4) has a temperature of 130℃~180℃, a pressure of 0.2~0.5MPa, and an aging time of 2~6h.

42. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The washing in step (4) includes two steps. The first step is to remove the medium oil on the molding material. The solvent is one or more of petroleum ether, cyclohexane, toluene, and anhydrous ethanol. The second step is to wash with deionized water at 70℃~90℃.

43. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The washing in step (4) includes two steps. The first step is to remove the medium oil on the molding material. The solvent is a mixture of at least one of petroleum ether, cyclohexane, and toluene with anhydrous ethanol. The volume ratio of anhydrous ethanol in the mixture is 25% to 50%. The second step is to wash with deionized water at 70°C to 90°C.

44. The method for preparing the hierarchical porous alumina material according to claim 12, characterized in that: The drying temperature in step (4) is 100℃~150℃ and the drying time is 6~10 hours; the calcination temperature is 750℃~950℃ and the calcination time is 1~4 hours.

45. A hierarchical porous alumina material obtained by the preparation method according to any one of claims 12-44.

46. ​​A heavy oil hydrogenation catalyst, wherein the catalyst uses the hierarchical porous alumina material as described in any one of claims 1-11 as a support.

47. The heavy oil hydrotreating catalyst according to claim 46, characterized in that: The active components are group VIII metals and / or group VIB metals. Based on the weight of the catalyst, the support content is 73% to 95%, the group VIII metal content as oxides is 0.5% to 5%, and the group VIB metal content as oxides is 4.0% to 20%.

48. The heavy oil hydrotreating catalyst according to claim 46, characterized in that: The active components are group VIII metals and / or group VIB metals. Based on the weight of the catalyst, the support content is 80% to 95%, the group VIII metal content is 1% to 4% as oxides, and the group VIB metal content is 4% to 15% as oxides.

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