Coal tar hydrogenation catalyst, its preparation method and application

Abstract

This invention discloses a coal tar hydrogenation catalyst, its preparation method, and its application. The catalyst comprises a support and an active metal component loaded on the support. The support has a spherical core-shell structure, with the core layer being alumina and the shell layer being an alumina-silica composite material. The active metal component is at least one of a Group VIB metal and / or a Group VIII metal. The preparation method includes the following steps: (1) mixing boehmite, a surfactant, and an oil phase material to obtain a first material; (2) preparing an acidified silica-containing solution; (3) mixing alumina sol, the acidified silica-containing solution, a curing agent, an emulsifier, and an additive to obtain a second material; (4) mixing the first material and the second material to prepare a support; and (5) introducing the active metal component onto the support to obtain the coal tar hydrogenation catalyst. This invention enables a gradual hydrogenation reaction of coal tar on a catalyst, improves the properties of the coal tar hydrogenation product, provides higher quality raw materials for subsequent processes, and improves the catalyst's water resistance.

Description

Technical Field

[0001] This invention belongs to the field of coal chemical technology, and relates to a hydrogenation catalyst and its preparation method, particularly to a coal tar hydrogenation catalyst, its preparation method, and its application. Background Technology

[0002] Coal tar is a liquid product obtained during the dry distillation and gasification of coal. It is a black or dark brown viscous liquid with a pungent odor and is the source of many fused-ring compounds and heterocyclic compounds containing O, N, and S. Based on different pyrolysis temperatures, coal tar can be classified into low-temperature coal tar, medium-temperature coal tar, and high-temperature coal tar. The properties of coal tar vary considerably depending on the dry distillation temperature. Compared to petroleum-based feedstocks, coal tar has a higher content of aromatics and asphaltenes, and also contains a large amount of oxygen-containing organic matter, mechanical impurities, and small amounts of sulfur and nitrogen molecules.

[0003] Coal tar hydrogenation technology is an effective way to rationally utilize coal tar resources. After hydrogenation, coal tar can yield naphtha and diesel components with relatively ideal sulfur, nitrogen, and oxygen content. The hydrogenated naphtha has a high aromatic potential content (45%–70%), making it suitable as a blending component for clean gasoline and even more suitable as a feedstock for catalytic reforming units to produce aromatics; the diesel component can be used as a blending component for diesel fuel.

[0004] Coal tar is rich in oxygen. During hydrogenation, oxygen is hydrogenated to produce water. Under high temperature and high pressure conditions, this water has an adverse effect on the pore structure and mechanical properties of the catalyst. Therefore, how to improve the water resistance of the catalyst while ensuring hydrogenation performance is a research direction.

[0005] CN201110005435.1 discloses a hydrocracking catalyst for coal tar to fuel oil production and its preparation and application methods. The hydrocracking catalyst consists of an active component, an additive, and a support. The active component is WO3 and NiO, the additive is ReO, and the support is composed of activated alumina, zeolite, and BaO. Calculated in oxide form, the active component and the additive account for 14%-34% and 0.4%-1.2% of the total catalyst mass, respectively. The catalyst preparation steps include support preparation, support pretreatment, impregnation, and catalyst post-treatment, introducing a new ultrasonic impregnation technology and strictly controlling the catalyst preparation conditions. The catalyst possesses good aromatic saturation activity and suitable cracking activity, as well as excellent high-temperature resistance and pressure resistance, effectively improving the quality and yield of the hydrotreated product oil. While this patent enhances the catalyst's water resistance by adding alkaline BaO to form barium aluminum spinel, the addition of alkaline substances also reduces the catalyst's acidity, which is detrimental to the optimal activity of the molecular sieve. Furthermore, the catalyst preparation process is relatively complex and unsuitable for large-scale industrial production.

[0006] CN202110144831.6 discloses a coal tar hydrogenation catalyst and its preparation method. The catalyst includes a first active material and a second active material. The first active material includes at least one group VIB oxide, and the second active material includes at least one group IB, VIIB, or VIII oxide. The molar ratio M1 / M2 of the first active material and the second active material M2 is 10–1. The catalyst support is a molecular sieve that has undergone pore-expanding treatment, and the active component is also doped with carbon. The preparation method of the catalyst is as follows: the support, active material precursor, and urea are subjected to low-temperature hydrothermal treatment to obtain catalyst precursor A; catalyst precursor A is impregnated in a carbon source-containing solution to obtain catalyst precursor B; catalyst precursor B is heat-treated in an inert atmosphere to obtain the catalyst. In this patent, the addition of carbon can partially improve the catalyst's water resistance, but the amount of carbon added is relatively small, and its effect is limited, making it not very suitable for coal tar with high oxygen content. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention aims to provide a highly water-resistant coal tar hydrogenation catalyst, its preparation method, and its applications. The coal tar hydrogenation catalyst provided by this invention has a spherical core-shell structure, with alumina as the core and an alumina-silica composite material as the shell. Since the deoxygenation and demetallization of coal tar mainly occur as surface reactions, the shell layer's large pores and weak acidity facilitate shallow hydrogenation and demetallization reactions of the coal tar feedstock. Further deep hydrogenation and conversion reactions then occur in the core layer. This allows for a gradual hydrogenation reaction of coal tar on a single catalyst, improving the properties of the hydrogenated coal tar product and providing higher-quality feedstock for subsequent processes. Simultaneously, the alumina-silica composite material enhances the catalyst's water resistance.

[0008] The first aspect of the present invention provides a coal tar hydrogenation catalyst, the catalyst comprising a support and an active metal component supported on the support, wherein the support is a spherical core-shell structure, wherein the core layer is alumina and the shell layer is an alumina-silica composite material, and the active metal component is at least one of a group VIB metal and / or a group VIII metal, particularly at least one selected from Mo, W, Ni, and Co.

[0009] Furthermore, in the above-mentioned coal tar hydrogenation catalyst, based on the weight of the catalyst, the content of Group VIB metals as oxides is 5wt% to 25wt%, preferably 8wt% to 23wt%; and the content of Group VIII metals as oxides is 1wt% to 10wt%, preferably 1wt% to 6wt%.

[0010] Furthermore, in the above-mentioned coal tar hydrogenation catalyst, the specific surface area of ​​the catalyst is 100–250 m². 2 / g, preferably 120-220m 2 / g.

[0011] Furthermore, in the above-mentioned coal tar hydrogenation catalyst, the pore volume of the catalyst is 0.4 to 0.7 mL / g, preferably 0.45 to 0.7 mL / g.

[0012] Furthermore, in the above-mentioned coal tar hydrogenation catalyst, the total acid value of the catalyst is 0.2 to 0.5 mmol / g, preferably 0.3 to 0.5 mmol / g.

[0013] Furthermore, in the above-mentioned coal tar hydrogenation catalyst, the shell thickness of the catalyst accounts for 30% to 60% of the catalyst particle diameter.

[0014] Furthermore, in the above-mentioned coal tar hydrogenation catalyst, the particle size of the catalyst is 0.5-2.0 mm, preferably 0.5-1.5 mm.

[0015] Furthermore, in the above-mentioned coal tar hydrogenation catalyst, the catalyst wear index is ≤0.05%, and the lateral pressure strength is greater than 15 N / mm.

[0016] A second aspect of this invention provides a method for preparing a coal tar hydrogenation catalyst, comprising the following steps:

[0017] (1) Mix the pseudoboehmite, surfactant, and oil phase materials, and disperse them evenly to obtain the first material;

[0018] (2) The silicon source is contacted with acid for acidification treatment, and the acidified silicon-containing solution is obtained after treatment;

[0019] (3) Mix the aluminum sol, the acidified silicon-containing solution obtained in step (2), the curing agent, the emulsifier, and the additives, and mix them evenly to obtain the second material;

[0020] (4) The first material obtained in step (1) is mixed with the second material obtained in step (3). After the mixture is evenly mixed, an oil-in-water emulsion is obtained. The emulsion is then shaped, aged, extracted, washed, dried and calcined to obtain a carrier.

[0021] (5) After introducing active metal components onto the support obtained in step (4), a coal tar hydrogenation catalyst is obtained.

[0022] Furthermore, in the above-mentioned method for preparing the coal tar hydrogenation catalyst, the particle size of the pseudoboehmite in step (1) is 2.0–10.0 micrometers, preferably 3.0–8.0 micrometers; specifically, the pseudoboehmite can be processed in a grinding device with crushing function, such as a ball mill, to obtain a pseudoboehmite sample with the required particle size. The pseudoboehmite, after being calcined at 500℃–650℃, has the following properties: specific surface area of ​​280–350 m². 2 / g, pore volume is ≥0.95mL / g.

[0023] Furthermore, in the above-mentioned method for preparing the coal tar hydrogenation catalyst, the hydrophilic-lipophilic balance (HLB) value of the surfactant mentioned in step (1) is 16-18, specifically at least one of Tween 20, Pinto-Gibberellic Acid O-25, and Pinto-Gibberellic Acid O-30. The amount of surfactant added is 5.0% to 15.0% of the mass of boehmite.

[0024] Furthermore, in the above-mentioned method for preparing coal tar hydrogenation catalyst, the kinematic viscosity of the oil phase material in step (1) at 40°C is 20-40 mm. 2 / s, preferably 25-35mm 2 / s. More specifically, the oil phase material can 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; further, the amount of the oil phase material added is 1.0 to 3.0 times the mass of boehmite, preferably 1.5 to 2.5 times.

[0025] Furthermore, in the above-mentioned method for preparing coal tar hydrogenation catalyst, the dispersion in step (1) is carried out under ultrasonic conditions, and the frequency of the ultrasonic waves is 25KHZ to 130KHZ.

[0026] Furthermore, in the above-mentioned method for preparing coal tar hydrogenation catalyst, the solid content of the first material obtained in step (1) is 25wt% to 40wt%.

[0027] Furthermore, in the above-mentioned method for preparing the coal tar hydrogenation catalyst, the silicon source in step (2) is a silicon-containing alkaline solution, specifically selected from one or more of water glass and alkaline silica sol, preferably water glass. The concentration of the silicon source solution, calculated as SiO2, is 5wt% to 30wt%, and the modulus is generally 2.5 to 3.2.

[0028] Furthermore, in the above-mentioned method for preparing coal tar hydrogenation catalyst, the acid mentioned in step (2) is an inorganic acid, specifically selected from one or more of sulfuric acid, nitric acid, hydrochloric acid, etc., preferably nitric acid.

[0029] Furthermore, in the above-mentioned method for preparing coal tar hydrogenation catalyst, in step (2), the amount of acid is controlled to ensure that the pH value of the acidified silicon-containing solution is 1 to 4, preferably 2 to 4.

[0030] Furthermore, in the above-mentioned method for preparing the coal tar hydrogenation catalyst, the Al2O3 mass content in the aluminum sol in step (3) is 20% to 45%, preferably 25% to 40%. The aluminum sol can be prepared by 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.

[0031] Furthermore, in the above-mentioned method for preparing coal tar hydrogenation catalyst, the curing agent in step (3) is one or more of hexamethylenetetramine and urea, preferably hexamethylenetetramine; more preferably, the mass concentration of the curing agent is 30% to 70%; the amount of curing agent added is 1% to 15% of the mass of alumina in the aluminum sol, preferably 2.5% to 12%.

[0032] Furthermore, in the above-mentioned method for preparing the coal tar hydrogenation catalyst, 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 0.2% to 2.0% of the mass of alumina in the aluminum sol, preferably 0.5% to 1.5%.

[0033] Furthermore, in the above-mentioned method for preparing coal tar hydrogenation catalyst, the auxiliary agent mentioned in step (3) is one or more of methacryloyloxyethyltrimethylammonium chloride (DMC), dimethyl diallyl ammonium chloride (DMDAAC), acryloyloxyethyltrimethylammonium chloride (DAC), and polyacrylamide, preferably polyacrylamide; the concentration of the auxiliary agent is 1wt% to 5wt%, and the amount of the auxiliary agent added is 1wt% to 10wt% of the mass of alumina in the alumina sol.

[0034] Furthermore, in the above-mentioned method for preparing coal tar hydrogenation catalyst, the mass ratio of SiO2 / Al2O3 in the second material in step (3) is 1:2 to 3:1, preferably 1:1 to 3:1.

[0035] Furthermore, in the above-mentioned method for preparing coal tar hydrogenation catalyst, the amount of boehmite added is 0.25 to 1.25 times the mass of alumina in the silica-alumina sol.

[0036] Furthermore, in the above-mentioned method for preparing coal tar hydrogenation catalyst, the solid content of the oil-in-water emulsion in step (4) is 15wt% to 20wt%.

[0037] Furthermore, in the above-mentioned method for preparing the coal tar hydrogenation catalyst, the molding in step (4) is carried out by oil column molding, 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.

[0038] Furthermore, in the above-mentioned method for preparing coal tar hydrogenation catalyst, the aging process described in step (4) has a temperature of 130℃~180℃, a pressure of 0.2~0.5MPa, and an aging time of 2~6h.

[0039] Furthermore, in the above-mentioned method for preparing coal tar hydrogenation catalyst, 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.

[0040] Furthermore, in the above-mentioned method for preparing coal tar hydrogenation catalyst, the drying temperature in step (4) is 100℃~150℃ and the drying time is 6~10 hours; the calcination temperature is 600℃~900℃ and the calcination time is 1~4 hours.

[0041] Furthermore, in the above-mentioned method for preparing coal tar hydrogenation catalyst, the active metal component in step (5) is a Group VIII metal and / or a Group VIB metal. Based on the weight of the catalyst, the content of the Group VIII metal as oxide is 0.5wt% to 5wt%, preferably 0.5wt% to 4.5wt%; the content of the Group VIB metal as oxide is 4wt% to 25wt%, preferably 4wt% to 20wt%.

[0042] Furthermore, in the above-mentioned method for preparing the coal tar hydrogenation catalyst, the active metal component in step (5) 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 the conventional impregnation method is used for loading, firstly, the 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℃, the drying time is 2~24h; the calcination temperature is 400℃~600℃, and the calcination time is 2~8h.

[0043] A third aspect of the present invention provides an application of the above-mentioned coal tar hydrogenation catalyst in the coal tar hydrogenation process.

[0044] Furthermore, in the above applications, the coal tar can be at least one selected from low-temperature coal tar, medium-low temperature coal tar, medium-temperature coal tar, and high-temperature coal tar.

[0045] Furthermore, in the above applications, the reaction conditions for the coal tar hydrogenation process are: reaction pressure of 10–20 MPaG, reaction temperature of 280℃–420℃, and liquid hourly space velocity of 0.1–1.5 h⁻¹. -1 The hydrogen-to-oil volume ratio is 100–1000.

[0046] In summary, the advantages of the coal tar hydrogenation catalyst and its preparation method provided by this invention are mainly reflected in the following aspects:

[0047] 1. In the method for preparing coal tar hydrogenation catalyst of the present invention, acidified silicon source and aluminum source are used as shell layer to form a silicon-aluminum-oxygen network structure during the preparation of spherical support, thereby improving the water resistance of the catalyst; at the same time, pseudoboehmite is used as core layer raw material, which is easy to bond tightly with silicon-aluminum material during the aging process of spherical support preparation, thereby further improving the water resistance and wear resistance of the catalyst.

[0048] 2. In the method for preparing coal tar hydrogenation catalyst of the present invention, by using a dispersant and combining it with ultrasonic treatment, the surface wetting and dispersion performance of finely ground boehmite is improved, ensuring that it can be uniformly dispersed in aluminum sol and ensuring the stability of the dispersion system. This solves the problem that the surface energy of finely ground boehmite is high and the dispersion is poor, making it impossible to prepare core-shell structure carriers.

[0049] 3. In the preparation method of the coal tar hydrogenation catalyst of the present invention, aluminum sol is made into an oil-in-water (O / W) emulsion. During droplet formation, the emulsion droplets enter the medium oil and automatically shrink into spheres 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 pseudoboehmite is in a free state in the aluminum sol solution. Then, through the physical and chemical changes of the additives, the particles change from repulsion to attraction through adsorption, bridging, cross-linking and neutralization of the charge on the surface of the suspended matter, thereby forming pseudoboehmite aggregates, which become 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 encapsulating the core structure to form gel spheres, thereby forming a core-shell structured spherical carrier.

[0050] 4. In the preparation method of the coal tar hydrogenation catalyst of the present invention, the aging treatment after molding at relatively high temperature and high pressure can further increase the pores of the shell layer and realize the stepped pore structure at the macroscopic level of the spherical carrier. At the same time, the aged material can be extracted to recover the organic matter therein, prevent environmental pollution, and avoid the problem of reduced strength caused by the decomposition of organic matter during the roasting process.

[0051] 5. The coal tar hydrogenation catalyst provided by this invention is a core-shell structured spherical catalyst of alumina-silica-alumina composite material. The combination of different materials can prepare catalysts with different pore size distributions and activity distributions from both macroscopic and microscopic perspectives. It can achieve the combination of multiple catalyst properties on one catalyst, which is more conducive to the gradual hydrogenation reaction of coal tar and improves the activity, stability and utilization rate of the catalyst. Detailed Implementation

[0052] 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.

[0053] 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.

[0054] The analytical methods of this invention are as follows: Specific surface area, pore volume, external specific surface area, and pore distribution were measured using a cryogenic liquid nitrogen physical adsorption method, employing an ASAP2405 or 2420 physical adsorption instrument manufactured by a US company; infrared acid content was measured using pyridine adsorption infrared spectroscopy, using a NICOLET 6700 Fourier transform infrared spectrometer; wear index was measured using the drum method, employing a KM-ZV wear meter; and metallic composition was measured using inorganic spectrophotometry. Lateral compressive strength was measured using a ZQJ-II intelligent particle strength testing machine.

[0055] The technical features of the present invention are further described below through embodiments, but are not limited to these embodiments.

[0056] Example 1

[0057] (1) Preparation of spherical carriers

[0058] 40g of pseudoboehmite (specific surface area 312m²) was used. 2 (g, pore volume 0.95mL / g, dry basis 70wt%) was ground into powder with a particle size ≤5.0 micrometers using a ball mill;

[0059] Add 3.5g of Pingpingjia O-25 to a solution with a kinematic viscosity of 30mm at 40℃. 2 In 100g of white oil per second, after stirring evenly, the above-ground powder was added, and then stirred under 80KHZ ultrasonication to obtain a uniformly dispersed system with a solid content of 27.87wt%.

[0060] Weigh 160g of water glass (SiO2 content 25wt%, modulus 2.7), and add 1.0mol / L nitric acid while stirring to adjust the pH of the mixture to 2, thus obtaining an acidified silicon-containing solution.

[0061] Weigh 128g of aluminum sol with a mass content of 25wt% prepared by reacting aluminum with hydrochloric acid solution, add it to the acidified silicon-containing solution and stir evenly, then add 10.6g of hexamethylenetetramine solution with a concentration of 36wt%, 64g of Tween 80 with a concentration of 1.0wt%, and 140g of polyacrylamide with a concentration of 2wt%, and stir to mix evenly to obtain an aluminum-silica sol mixture;

[0062] The above dispersion system was added to the silica-alumina sol mixture and mixed under a high shear device at a speed of 18,000 rpm to obtain an oil-in-water emulsion with a solid content of 15.51 wt%.

[0063] Using a dropper with an inner diameter of 1.2 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 160℃ and 0.3MPa for 2 hours. After aging, the 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 700℃ for 3 hours to obtain spherical carrier A-1.

[0064] (2) Preparation of spherical catalysts

[0065] Weigh 15.82 g of phosphoric acid and add 450 mL of distilled water. Then, add 45.4 g of molybdenum oxide and 20.8 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 A1 with solution L-1, dry it at 110 °C for 2 h, and calcine it at 450 °C for 3 h to obtain catalyst C-A1. Its properties are shown in Table 1.

[0066] Example 2

[0067] Other conditions were the same as in Example 1, except that Pingpingjia O-25 was replaced with Tween 20, the amount added was changed to 4.0g, the polyacrylamide was replaced with methacryloyloxyethyltrimethylammonium chloride, the temperature of the white oil in the oil column molding was changed to 105℃, and the aging conditions were changed to aging at 150℃ and 0.5MPa for 4h to obtain carrier A-2.

[0068] The support A2 was saturated with solution L-1, dried at 110℃ for 2 h, and calcined at 480℃ for 3 h to obtain catalyst C-A2, the properties of which are shown in Table 1.

[0069] Example 3

[0070] Other conditions are the same as in Example 1, except that the amount of boehmite is changed to 70g, and 3.5g of O-25 is added to a solution with a kinematic viscosity of 30mm at 40°C. 2 In 175g of white oil per s, water glass was replaced with silica sol (SiO2 content 20wt%), the amount added was changed to 170g, aluminum sol was changed to 68g, hexamethylenetetramine solution was used at 4.72g, Tween 60 with a concentration of 1.0wt% was used as emulsifier at 34g, and polyacrylamide was changed to 85g, thus obtaining carrier A-3.

[0071] The support A3 was saturated with solution L-1, dried at 110℃ for 2 h, and calcined at 520℃ for 4 h to obtain catalyst C-A3, the properties of which are shown in Table 1.

[0072] Example 4

[0073] (1) Preparation of spherical carriers

[0074] 50g of boehmite (specific surface area 348m²) was added. 2 (g, pore volume 1.15 mL / g, dry basis 70 wt%) was ground into powder with a particle size ≤ 4.0 micrometers using a ball mill;

[0075] Add 4.2g of Pingpingjia O-30 to a solution with a kinematic viscosity of 35mm at 40℃. 2 The powder was added to 125g of white oil per s after being stirred evenly, and then stirred under 120KHZ ultrasonication to obtain a uniform dispersion system with a solid content of 27.60wt%.

[0076] Weigh 180g of water glass (SiO2 content 25wt%, modulus 2.7), and add 2.0mol / L nitric acid while stirring to adjust the pH of the mixture to 3, thus obtaining an acidified silicon-containing solution.

[0077] Weigh 80g of aluminum sol with an Al2O3 content of 25% prepared by reacting aluminum with hydrochloric acid solution, add it to the acidified silicon-containing solution and stir evenly. Then add 8.30g of hexamethylenetetramine solution with a concentration of 36wt%, 40g of Tween 60 with a concentration of 1.0wt%, and 66g of polyacrylamide with a concentration of 3wt%. Stir and mix evenly to obtain an aluminum-silica sol mixture.

[0078] The above dispersion system was added to the silica-alumina sol mixture and mixed under a high shear speed of 18,000 rpm to obtain an oil-in-water emulsion with a solid content of 17.9 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. 2The 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 160℃ and 0.3MPa for 2 hours. After aging, the 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 650℃ for 3 hours to obtain spherical carrier A-1.

[0080] (2) Preparation of spherical catalysts

[0081] 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-2. Saturate impregnate support A-4 with solution L-2, dry at 110 °C for 2 h, and calcine at 480 °C for 5 h to obtain catalyst CA-4. Its properties are shown in Table 1.

[0082] Example 5

[0083] Other conditions are the same as in Example 4, except that Pingpingjia O-30 is changed to Pingpingjia O-25, the amount added is changed to 3.5g, hexamethylenetetramine is changed to urea, the amount added is changed to 5.56g, polyacrylamide is changed to methacryloyloxyethyltrimethylammonium chloride (DMC), the temperature of white oil in oil column molding is changed to 105℃, the aging conditions are changed to aging at 150℃ and 0.5MPa for 4h, and the carrier calcination temperature is changed to calcination at 750℃ for 4h to obtain carrier A-5.

[0084] The support A-5 was saturated with solution L-2, dried at 110℃ for 2 h, and calcined at 540℃ for 5 h to obtain catalyst CA-5, the properties of which are shown in Table 1.

[0085] Comparative Example 1

[0086] 40g of pseudoboehmite (specific surface area 312m²) was used. 2 (g, pore volume 0.95mL / g, dry basis 70wt%) was ground into powder with a particle size ≤5.0 micrometers using a ball mill;

[0087] The kinematic viscosity at 40℃ is 30 mm. 2 After mixing 100g of white oil per second evenly, add the above-ground powder and then stir under 80KHZ ultrasonication to obtain a uniformly dispersed system with a solid content of 28.57wt%.

[0088] Weigh 160g of water glass (SiO2 content 25wt%, modulus 2.7), and add 1.0mol / L nitric acid while stirring to adjust the pH of the mixture to 2, thus obtaining an acidified silicon-containing solution.

[0089] Weigh 128g of aluminum sol with an Al2O3 content of 25% prepared by reacting aluminum with hydrochloric acid solution, add it to the acidified silicon-containing solution and stir evenly. Then add 10.6g of hexamethylenetetramine solution with a concentration of 36wt%, 64g of Tween 80 with a concentration of 1.0%, and 140g of polyacrylamide with a concentration of 2%, and stir to mix evenly to obtain an aluminum-silica sol mixture.

[0090] The above dispersion system was added to the silica-alumina sol mixture and mixed under a high shear device at a speed of 18,000 rpm to obtain an oil-in-water emulsion with a solid content of 15.53 wt%.

[0091] Using a dropper with an inner diameter of 1.2 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 160℃ and 0.3MPa for 2 hours. After aging, the 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 700℃ for 3 hours to obtain spherical carrier F-1.

[0092] (2) Preparation of spherical catalysts

[0093] The support F-1 was saturated with solution L-1, dried at 110℃ for 2 h, and calcined at 450℃ for 3 h to obtain catalyst C-F1, the properties of which are shown in Table 1.

[0094] Comparative Example 2

[0095] (1) Preparation of spherical carriers

[0096] 40g of pseudoboehmite (specific surface area 312m²) was used. 2 (g, pore volume 0.95mL / g, dry basis 70%) was ground into powder with a particle size ≤5.0 micrometers using a ball mill;

[0097] Add 3.5g of Pingpingjia O-25 to a solution with a kinematic viscosity of 30mm at 40℃. 2 In 100g of white oil per second, after stirring evenly, the above-ground powder was added, and then stirred under 80KHZ ultrasonication to obtain a uniformly dispersed system with a solid content of 27.87wt%.

[0098] Weigh 160g of water glass (SiO2 content 25wt%, modulus 2.7), and add 1.0mol / L nitric acid while stirring to adjust the pH of the mixture to 2, thus obtaining an acidified silicon-containing solution.

[0099] Weigh 128g of aluminum sol with an Al2O3 content of 25% prepared by reacting aluminum with hydrochloric acid solution, add it to the acidified silicon-containing solution and stir evenly, then add 10.6g of hexamethylenetetramine solution with a concentration of 36wt% and 64g of Tween 80 with a concentration of 1.0wt%, stir and mix evenly to obtain an aluminum-silica sol mixture.

[0100] The above dispersion system was added to the silica-alumina sol mixture and mixed under a high shear device at a speed of 18,000 rpm to obtain an oil-in-water emulsion with a solid content of 19.7 wt%.

[0101] Using a dropper with an inner diameter of 1.2 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 160℃ and 0.3MPa for 2 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 700℃ for 3 hours to obtain spherical carrier F-2.

[0102] (2) Preparation of spherical catalysts

[0103] The support F-2 was saturated with solution L-1, dried at 110℃ for 2 h, and calcined at 450℃ for 3 h to obtain catalyst C-F2, the properties of which are shown in Table 1.

[0104] The physicochemical properties of the catalysts obtained above are listed in Table 1.

[0105] Table 1 Catalyst Properties

[0106]

[0107] The data in the table show that the catalyst prepared by this invention has a higher pore volume and specific surface area due to the formation of a core-shell structure, and a smaller wear index, making it particularly suitable for fluidized bed hydrogenation processes.

[0108] The catalysts prepared in Table 1 were evaluated for activity on a CSTR unit using medium-low temperature coal tar. The properties are shown in Table 2, and the evaluation conditions are shown in Table 3. 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 4.

[0109] Table 2 Properties of Crude Oil

[0110]

[0111] Table 3 Evaluation Criteria

[0112]

[0113] Table 4 Evaluation Results

[0114]

[0115] 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 5.

[0116] Table 5 Comparison of 2000h operation results

[0117]

[0118] 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 core-shell structure allows for the removal of metals from coal tar in the shell layer, followed by deep desulfurization and residual carbon conversion in the core layer. This achieves a step-by-step conversion of coal tar on a single catalyst, improving catalyst utilization.

Claims

1. A coal tar hydrogenation catalyst, the catalyst comprising a support and an active metal component supported on the support, wherein the support has a spherical core-shell structure, wherein the core layer is alumina and the shell layer is an alumina-silica composite material, and the active metal component is at least one of a Group VIB metal and / or a Group VIII metal, wherein, based on the weight of the catalyst, the content of the Group VIB metal as oxide is 5 wt% to 25 wt%; the content of the Group VIII metal as oxide is 1 wt% to 10 wt%; and the shell thickness of the catalyst is 30% to 60% of the catalyst particle diameter. The preparation method of the coal tar hydrogenation catalyst includes the following steps: (1) Mix the pseudoboehmite, surfactant, and oil phase materials, and disperse them evenly to obtain the first material; (2) The silicon source is contacted with acid for acidification treatment, and the acidified silicon-containing solution is obtained after treatment; (3) Mix the aluminum sol, the acidified silicon-containing solution obtained in step (2), the curing agent, the emulsifier, and the additives, and mix them evenly to obtain the second material; the additives are one or more of methacryloyloxyethyltrimethylammonium chloride, dimethyl diallyl ammonium chloride, acryloyloxyethyltrimethylammonium chloride, and polyacrylamide; the curing agent is one or more of hexamethylenetetramine and urea; (4) The first material obtained in step (1) is mixed with the second material obtained in step (3). After the mixture is evenly mixed, an oil-in-water emulsion is obtained. The emulsion is then shaped, aged, extracted, washed, dried and calcined to obtain a carrier. (5) An active metal component is introduced onto the carrier obtained in step (4) to obtain a coal tar hydrogenation catalyst.

2. The coal tar hydrogenation catalyst according to claim 1, characterized in that: Based on the weight of the catalyst, the content of Group VIB metals as oxides is 8 wt% to 23 wt%; the content of Group VIII metals as oxides is 1 wt% to 6 wt%.

3. The coal tar hydrogenation catalyst according to claim 1, characterized in that: The active metal component is at least one selected from Mo, W, Ni, and Co.

4. The coal tar hydrogenation catalyst according to claim 1, characterized in that: The specific surface area of ​​the catalyst is 100–250 m². 2 / g.

5. The coal tar hydrogenation catalyst according to claim 1, characterized in that: The specific surface area of ​​the catalyst is 120–220 m². 2 / g.

6. The coal tar hydrogenation catalyst according to claim 1, characterized in that: The catalyst has a pore volume of 0.4–0.7 mL / g.

7. The coal tar hydrogenation catalyst according to claim 1, characterized in that: The catalyst has a pore volume of 0.45–0.7 mL / g.

8. The coal tar hydrogenation catalyst according to claim 1, characterized in that: The total acid value of the catalyst is 0.2–0.5 mmol / g.

9. The coal tar hydrogenation catalyst according to claim 1, characterized in that: The total acid value of the catalyst is 0.3–0.5 mmol / g.

10. The coal tar hydrogenation catalyst according to claim 1, characterized in that: The particle size of the catalyst is 0.5–2.0 mm.

11. The coal tar hydrogenation catalyst according to claim 1, characterized in that: The particle size of the catalyst is 0.5–1.5 mm.

12. The coal tar hydrogenation catalyst according to claim 1, characterized in that: The catalyst has an attrition index of ≤0.05% and a lateral compressive strength of greater than 15 N / mm.

13. A method for preparing the coal tar hydrogenation catalyst according to any one of claims 1-12, comprising the following steps: (1) The pseudoboehmite, surfactant, and oil phase material are mixed and dispersed evenly to obtain the first material; (2) The silicon source is contacted with acid for acidification treatment, and the acidified silicon-containing solution is obtained after treatment; (3) Mix the aluminum sol, the acidified silicon-containing solution obtained in step (2), the curing agent, the emulsifier, and the additives, and mix them evenly to obtain the second material; the additives are one or more of methacryloyloxyethyltrimethylammonium chloride, dimethyl diallyl ammonium chloride, acryloyloxyethyltrimethylammonium chloride, and polyacrylamide; the curing agent is one or more of hexamethylenetetramine and urea; (4) The first material obtained in step (1) is mixed with the second material obtained in step (3). After the mixture is evenly mixed, an oil-in-water emulsion is obtained. The emulsion is then shaped, aged, extracted, washed, dried and calcined to obtain a carrier. (5) An active metal component is introduced onto the carrier obtained in step (4) to obtain a coal tar hydrogenation catalyst.

14. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: The pseudoboehmite particle size mentioned in step (1) is 2.0–10.0 micrometers; the properties of the pseudoboehmite after calcination at 500℃–650℃ are as follows: specific surface area is 280–350 m². 2 / g, pore volume greater than or equal to 0.95mL / g.

15. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: The pseudoboehmite particle size mentioned in step (1) is 3.0–8.0 micrometers; the properties of the pseudoboehmite after calcination at 500℃–650℃ are as follows: specific surface area is 280–350 m². 2 / g, pore volume greater than or equal to 0.95mL / g.

16. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: The surfactant mentioned in step (1) has a hydrophilic-lipophilic balance value of 16 to 18, and the surfactant is at least one of Tween 20, Pinto-PineO-25, and Pinto-PineO-30; the amount of surfactant added is 5.0% to 15.0% of the mass of boehmite.

17. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: The kinematic viscosity of the oil phase material in step (1) at 40°C is 20–40 mm. 2 / s; the oil phase material is selected from at least one of white oil, diesel oil, kerosene, lubricating oil, and C10-C15 alkane compounds; the amount of the oil phase material added is 1.0 to 3.0 times the mass of boehmite.

18. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: The kinematic viscosity of the oil phase material in step (1) at 40°C is 25–35 mm. 2 / s; the oil phase material is white oil and / or diesel oil; the amount of the oil phase material added is 1.5 to 2.5 times the mass of the pseudoboehmite.

19. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: The silicon source mentioned in step (2) is a silicon-containing alkaline solution, selected from one or more of water glass and alkaline silica sol; the concentration of the silicon source solution is 5wt% to 30wt% based on SiO2, and the modulus is 2.5 to 3.

2.

20. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: The silicon source mentioned in step (2) is water glass; the concentration of the silicon source solution is 5wt% to 30wt% based on SiO2, and the modulus is 2.5 to 3.

2.

21. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: The acid mentioned in step (2) is an inorganic acid, which is selected from one or more of sulfuric acid, nitric acid, and hydrochloric acid.

22. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: The acid mentioned in step (2) is an inorganic acid, and the inorganic acid is nitric acid.

23. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: In step (2), the amount of acid used is controlled to ensure that the pH value of the acidified silicon-containing solution is 1 to 4.

24. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: In step (2), the amount of acid used is controlled to ensure that the pH value of the acidified silicon-containing solution is 2 to 4.

25. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: The mass content of Al2O3 in the aluminum sol in step (3) is 20% to 45%.

26. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: The mass content of Al2O3 in the aluminum sol in step (3) is 25% to 40%.

27. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: The mass concentration of the curing agent in step (3) is 30% to 70%; the amount of curing agent added is 1% to 15% of the mass of alumina in the aluminum sol.

28. The method for preparing the coal tar hydrogenation catalyst according to claim 13, 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 curing agent added is 2.5% to 12% of the mass of alumina in the aluminum sol.

29. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: The emulsifier mentioned 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.

30. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: The emulsifier mentioned in step (3) is selected from at least one of Tween 40, Tween 60, Tween 80, AEO-7, AEO-9, and AEO-15.

31. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: In step (3), the concentration of the emulsifier is 0.5wt% to 2.5wt%, and the amount of emulsifier added is 0.2% to 2.0% of the mass of alumina in the aluminum sol.

32. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: In step (3), the concentration of the emulsifier is 0.5wt% to 2.5wt%, and the amount of emulsifier added is 0.5% to 1.5% of the mass of alumina in the aluminum sol.

33. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: The additive mentioned in step (3) is 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 aluminum sol.

34. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: In step (3), the mass ratio of SiO2 / Al2O3 in the second material is 1:2 to 3:

1.

35. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: In step (3), the mass ratio of SiO2 / Al2O3 in the second material is 1:1 to 3:

1.

36. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: The amount of boehmite added is 0.25 to 1.25 times the mass of alumina in the silica-alumina sol.

37. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: In step (4), the solid content of the oil-in-water emulsion is 15wt% to 20wt%.

38. The method for preparing the coal tar hydrogenation catalyst according to claim 13, 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 column 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℃.

39. The method for preparing the coal tar hydrogenation catalyst according to claim 13, 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 column 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℃.

40. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: The aging process described in step (4) has a temperature of 130℃~180℃, a pressure of 0.2~0.5MPa, and an aging time of 2~6h.

41. The method for preparing the coal tar hydrogenation catalyst according to claim 13, characterized in that: In step (4), the drying temperature is 100℃~150℃ and the drying time is 6~10 hours; the calcination temperature is 600℃~900℃ and the calcination time is 1~4 hours.

42. The application of the coal tar hydrogenation catalyst according to any one of claims 1-12 in the coal tar hydrogenation process.

43. The application according to claim 42, characterized in that: The coal tar is selected from at least one of low-temperature coal tar, medium-low-temperature coal tar, medium-temperature coal tar, and high-temperature coal tar.

44. The application according to claim 42, characterized in that: The reaction conditions for coal tar hydrogenation are: reaction pressure of 10–20 MPaG, reaction temperature of 280℃–420℃, and liquid hourly space velocity of 0.1–1.5 h⁻¹. -1 The hydrogen-to-oil volume ratio is 100–1000.

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