Residue oil hydrodemetallization catalyst and preparation method thereof

Abstract

The present invention discloses a hydrodemetallization catalyst and its preparation method. The catalyst comprises a catalyst body, a secondary outer layer, and a macroporous alumina layer. Active metals are distributed in the catalyst body and the secondary outer layer, with the active metal content in the secondary outer layer being lower than that in the catalyst body. The thickness ratio of the macroporous alumina layer to the secondary outer layer is 3:5 to 3:2. The catalyst exhibits strong resistance to carbon deposition and metal tolerance, and when used in residual oil hydrodemetallization reactions, it facilitates the long-term operation of residual oil hydrotreating units.

Description

[0001] Technology

[0002] The present invention relates to a hydrodemetallization catalyst and a preparation method thereof, and in particular to a hydrodemetallization catalyst suitable for heavy oil, especially residual oil hydrotreating process and a preparation method thereof. Background Art

[0003] With the increasing scarcity of crude oil resources and the increasing heaviness of crude oil, heavy oil hydroprocessing technology is gaining increasing attention. Heavy oil contains a large number of metals, such as nickel, vanadium, iron, calcium, and sodium. In particular, nickel and vanadium are primarily present as porphyrin and non-porphyrin compounds in the colloids and asphaltenes of heavy oil. The presence of metals can easily increase bed pressure drop and catalyst deactivation, adversely affecting subsequent heavy oil processing. Therefore, heavy oil hydrodemetallization catalysts are crucial in medium and heavy oil hydroprocessing technology.

[0004] During the residue hydrotreating process, nickel and vanadium can only be removed when large colloidal and asphaltene molecules enter the catalyst and disrupt its structure. The controlling step in the heavy oil hydrodemetallization reaction is the diffusion of reactants and products within the catalyst. The pore size and volume of the catalyst determine the diffusion path and accommodation space for the reactants. Increasing the pore volume and pore size of the catalyst is the best way to improve the metal-holding capacity of the demetallization catalyst.

[0005] CN106622265A discloses a method for preparing a residue oil hydrodemetallization catalyst. The method comprises the following steps: weighing a certain amount of pseudo-boehmite dry rubber powder, carbon black powder impregnated with an ammonium salt aqueous solution, and an extrusion aid, mixing the mixture, then adding an aqueous solution containing a peptizing agent and a chemical pore-enlarging agent, uniformly mixing the resulting materials, and extruding the extruded materials into strips. The extruded materials are dried and calcined to obtain an alumina carrier. The alumina carrier is used as the carrier and loaded with active metal components Mo and Ni by an impregnation method to obtain a residue oil hydrodemetallization catalyst.

[0006] CN106622265A discloses a hydrodemetallization catalyst, a preparation method, and an application thereof. The catalyst contains an active metal component and a modified hydrogenation catalyst support. The modified hydrogenation catalyst support is prepared by the following method: the method comprises: repeatedly impregnating and drying the hydrothermally treated support in sequence, and calcining the dried product obtained in the last step.

[0007] CN111097432A discloses a hydrodemetallization catalyst and its preparation method. The hydrodemetallization catalyst comprises a modified alumina support SII containing the first active metal component and a second active metal component. The modified alumina support SII comprises a main body and a rod-shaped portion. The main body has micron-sized pores, and at least part of the rod-shaped portion is distributed on the outer surface of the main body and in the micron-sized pores having a pore diameter D of 3 to 10 μm. The active metal content of the rod-shaped portion in the micron-sized pores is higher than the active metal content in the bulk phase of the hydrodemetallization catalyst.

[0008] CN109833890A discloses a residue oil hydrogenation catalyst and its preparation. The method comprises the following steps: spraying a residue oil hydrogenation demetallization catalyst carrier with an organic solvent containing a spam surfactant, followed by drying; impregnating the dried carrier with an active metal solution containing polyacrylate groups, followed by drying and calcining to produce the catalyst. While the metal dispersion of the residue oil hydrogenation catalyst prepared by this method is improved, the catalyst still contains a large amount of active metal components on its outer surface, resulting in metal deposition and surface coking, and a short catalyst lifespan. Summary of the Invention

[0009] In response to the problems in the prior art of severe carbon deposition and metal deposition on the surface of hydrodemetallization catalysts and poor long-term operation capacity of hydrogenation units, the present invention provides a residue oil hydrodemetallization catalyst and a preparation method thereof, so as to improve the carbon deposition and metal deposition problems on the surface of the hydrodemetallization catalyst, and provide technical support for the long-term operation of residue oil hydrogenation units.

[0010] The first aspect of the present invention provides a residue hydrodemetallization catalyst, comprising a catalyst body composed of a carrier and an active metal, a sub-outer layer and a macroporous alumina layer, wherein the sub-outer layer comprises macroporous alumina and the active metal; the active metal comprises molybdenum and nickel, the content of the active metal in the sub-outer layer as oxide accounts for 0.01% to 7.41% of the total active metal loading in the catalyst, and the thickness ratio of the macroporous alumina layer to the sub-outer layer is 3:5 to 3:2.

[0011] In the present invention, the sub-outer layer comprises macroporous alumina and active metal, and the pore volume of the sub-outer layer is 0.80-1.25 cm 3 / g (mercury intrusion method), specific surface area is 160~240m 2 / g.

[0012] In the present invention, the pore volume of the macroporous alumina layer is 0.90 to 1.25 cm 3 / g (mercury intrusion method), specific surface area is 160~260m 2 / g, and the thickness of the macroporous alumina layer is 50-100 μm.

[0013] In the present invention, the carrier in the catalyst body can be an alumina-based carrier, and the pore volume of the carrier is 0.65 to 1.25 cm 3 / g, preferably 0.70 to 1.20 cm 3 / g, with a specific surface area of ​​100 to 240 m 2 / g.

[0014] In the present invention, the content of molybdenum oxide in the catalyst is 2.50% to 20.00%, and the content of nickel oxide is 0.50% to 5.00%, based on the mass of the catalyst.

[0015] In the present invention, based on the total molybdenum oxide loading in the catalyst, the content of molybdenum oxide in the sub-outer layer is 0.01% to 7.41%, and based on the total nickel oxide loading in the catalyst, the content of nickel oxide in the sub-outer layer is 0.01% to 7.41%.

[0016] The second aspect of the present invention provides a method for preparing the above-mentioned residue hydrodemetallization catalyst, comprising the following steps:

[0017] (1) impregnating the support with active metal impregnation solution R1 and drying to obtain the catalyst body;

[0018] (2) Preparation of macroporous pseudo-boehmite slurry:

[0019] (3) mixing the macroporous pseudo-boehmite slurry obtained in step (2) with the active metal impregnation solution R1 in a certain proportion to obtain the active metal impregnation solution R2;

[0020] (4) using the active metal impregnation solution R2 obtained in step (3) to wrap the catalyst body obtained in step (1), and drying it to obtain a catalyst intermediate (second outer layer);

[0021] (5) The catalyst intermediate obtained in step (4) is impregnated with the macroporous pseudo-boehmite slurry prepared in step (2), and the mixture is dried and calcined to obtain the residual oil hydrodemetallization catalyst.

[0022] In the method of the present invention, in step (1) and step (3), the active metal impregnation solution R1 is a salt solution containing molybdenum and nickel, wherein the active metal molybdenum is derived from at least one of molybdenum oxide, ammonium molybdate, and molybdenum nitrate, and the nickel is derived from at least one of basic nickel carbonate, nickel carbonate, nickel nitrate, and nickel sulfate. The content of MoO3 in the active metal impregnation solution R1 is 3.00 to 14.00 g / 100 ml, and the content of NiO is 0.50 to 3.50 g / 100 ml. The amount of molybdenum oxide introduced into the catalyst from the active metal impregnation solution R1 in step (1) is 92.59% to 99.99% of the total molybdenum oxide loading in the catalyst, and the amount of nickel oxide introduced into the catalyst from the active metal impregnation solution R1 in step (1) is 92.59% to 99.99% of the total nickel oxide loading in the catalyst.

[0023] In the method of the present invention, the impregnation method in step (1) can be saturated impregnation or supersaturated impregnation. The amount of active metal impregnation solution R1 is 1.05 to 1.25 times the saturated water absorption rate of the support. The drying conditions are drying at 100 to 160°C for 2 to 12 hours.

[0024] In the method of the present invention, the method for preparing the macroporous pseudo-boehmite slurry in step (2) comprises:

[0025] a) neutralizing an acidic aluminum salt solution and an alkaline aluminum salt solution to obtain a slurry;

[0026] b) subjecting the slurry obtained in step a) to a first-stage aging, and after the first-stage aging, adding a water-soluble polymer A to conduct a second-stage aging;

[0027] c) filtering and washing the material after the second aging stage in step b), and then adding water to slurry to obtain the macroporous pseudo-boehmite slurry.

[0028] In the method of the present invention, in step a), the acidic aluminum salt solution and the alkaline aluminum salt solution are added to the reactor in parallel, and the addition time is 30 to 120 minutes.

[0029] In the method of the present invention, the acidic aluminum salt in step a) is selected from one or more of aluminum sulfate and aluminum nitrate solutions; the concentration of the acidic aluminum salt solution is 5g / 100mL to 18g / 100mL in terms of Al2O3.

[0030] In the method of the present invention, the alkaline aluminum salt solution in step a) is one or more of sodium metaaluminate solution and potassium metaaluminate solution; the concentration of the alkaline aluminum salt solution in terms of Al2O3 is 15g / 100mL to 45g / 100mL.

[0031] In the method of the present invention, the neutralization reaction in step a) is carried out at a temperature of 85 to 110° C. for 30 to 120 minutes, and the pH of the slurry is controlled to be 7.0 to 9.0 during the neutralization reaction. The pH of the slurry is controlled during the neutralization reaction by controlling the amount of the acidic aluminum salt solution and the alkaline aluminum salt solution added or by adding an additional acid-base modifier.

[0032] In the method of the present invention, the temperature of the first stage aging in step b) is 130-250° C., the time is 60-200 min, and the pH value is 9.0-11.0.

[0033] In the method of the present invention, the water-soluble polymer A in step b) is one or more of polyethylene glycol, polyvinyl alcohol, polyacrylamide and methyl cellulose.

[0034] In the method of the present invention, the amount of water-soluble polymer A added in step b) is such that the concentration of the water-soluble polymer A in the system after addition is 1 to 10 g / 100 mL and the viscosity of the system after addition of the water-soluble polymer A (at 20° C.) is 100 to 500 mPa·s.

[0035] In the method of the present invention, after the first stage aging in step b) is completed, the slurry is preferably concentrated so that the volume after concentration is 40% to 70% of the original volume.

[0036] In the method of the present invention, the temperature of the second stage aging in step b) is 150-300° C., and the time is 45-200 minutes. The temperature of the second stage aging is higher than that of the first stage aging, preferably 20-50° C. higher.

[0037] In the method of the present invention, the filtering, washing and beating in step c) are conventional technical means in the art.

[0038] In the method of the present invention, the alumina content in the macroporous pseudo-boehmite slurry in step c) is 10 to 100 g / L.

[0039] In the method of the present invention, in step (3), the macroporous pseudo-boehmite slurry obtained in step (2) is mixed with the active metal impregnation solution R1, so that the mass of the molybdenum oxide provided in the active metal impregnation solution R1 accounts for 0.15% to 11.12% of the total mass of the aluminum oxide provided in the macroporous pseudo-boehmite slurry and the metal oxides (MoO3 + NiO) provided in the active metal impregnation solution R1, and the mass of the nickel oxide provided in the active metal impregnation solution R1 accounts for 0.02% to 2.78% of the total mass of the aluminum oxide provided in the macroporous pseudo-boehmite slurry and the metal oxides (MoO3 + NiO) provided in the active metal impregnation solution R1.

[0040] In the method of the present invention, in step (4), the active metal impregnation solution R2 obtained in step (3) is used to coat the catalyst body obtained in step (1). The catalyst body obtained in step (1) is added to the active metal impregnation solution R2 obtained in step (3) and stirred for a soaking time of 3 seconds to 20 minutes. After the surface is coated with the impregnation solution R2, the catalyst body is removed and centrifuged for 1 to 20 minutes to remove excess surface solution. The catalyst body is then dried at 100 to 160° C. for 2 to 12 hours. The thickness of the secondary outer layer can be controlled by controlling the alumina content in the active metal impregnation solution R2, the soaking time, and the centrifugation time.

[0041] In the method of the present invention, in step (4), the content of molybdenum oxide introduced into the catalyst from the active metal impregnation liquid R2 is 0.01% to 7.41% of the total molybdenum oxide loading in the catalyst, and the content of nickel oxide introduced into the catalyst from the active metal impregnation liquid R2 is 0.01% to 7.41% of the total nickel oxide loading in the catalyst.

[0042] In the method of the present invention, before the catalyst body obtained in step (1) is wrapped with the active metal impregnation solution R2 obtained in step (3) in step (4), the catalyst body is preferably immersed in a binder solution. The binder content of the binder in the binder solution is 1% to 80% by weight, preferably 2% to 20%. The binder solution is composed of a binder and purified water. The binder can be one or more of starch, dextrin, polyvinyl alcohol, or carboxymethyl cellulose. Preferably, the catalyst body is immersed in the binder solution for 5 to 60 seconds, excess binder solution is drained off, and the catalyst body is left at room temperature for 15 to 60 minutes.

[0043] In the method of the present invention, in step (5), the catalyst intermediate obtained in step (4) is impregnated with the macroporous pseudo-boehmite slurry prepared in step (2). The catalyst intermediate obtained in step (4) is added to the macroporous pseudo-boehmite slurry obtained in step (2) and stirred for a soaking time of 2 seconds to 20 minutes. After the surface is coated with the macroporous pseudo-boehmite slurry, the catalyst intermediate is removed and centrifuged in a centrifuge for 1 to 20 minutes to remove excess slurry from the surface. The catalyst intermediate is then dried at 100 to 160° C. for 2 to 12 hours. The thickness of the surface layer can be controlled by the soaking time and the centrifugation time.

[0044] In the method of the present invention, the calcination conditions in step (5) are: calcination at 450-600° C. for 2-6 hours, and the calcination is carried out in an oxygen-containing atmosphere.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] 1. The residue oil hydrodemetallization catalyst of the present invention comprises a catalyst body, a sub-outer layer and a macroporous alumina layer. The macroporous alumina layer has large pores, can accommodate a large amount of carbon deposits, and is free of active metals, thereby preventing a violent hydrogenation reaction from occurring on the outer surface. The sub-outer layer has a lower active metal content than the catalyst body, resulting in a more moderate hydrogenation reaction. The sub-outer layer also has larger pores, which can accommodate a large amount of metal sulfides and carbon deposits without causing pore blockage. When used in a residue oil hydrogenation reaction, the catalyst can significantly improve its carbon deposition resistance and metal accommodating capacity, thereby facilitating the long-term operation of a residue oil hydrogenation unit.

[0047] 2. In the preparation process of the residual oil hydrodemetallization catalyst of the present invention, the catalyst body is first prepared, and then the macroporous pseudo-boehmite slurry is mixed with the active metal impregnation liquid R1 in a certain proportion to obtain the active metal impregnation liquid R2, and the catalyst body is wrapped with R2 so that the surface of the catalyst body is wrapped with an active metal layer with less active metal content than the catalyst body, and finally coated with a macroporous alumina layer. The sub-outer layer of the catalyst prepared by the method of the present invention can accommodate larger carbon deposits and metal deposits. It is a catalyst that integrates the functions of a protective agent and a demetallization catalyst in one. The macroporous alumina layer on the surface has no active metal, which avoids the occurrence of violent hydrogenation reactions and can accommodate larger carbon deposits and metal deposits. In summary, the method of the present invention significantly improves the carbon deposition resistance and metal tolerance of the residual oil hydrodemetallization catalyst finally prepared through the comprehensive coordination of various steps, and at the same time significantly extends the operating cycle of the hydrogenation unit. DETAILED DESCRIPTION

[0048] The following examples further illustrate the technical solutions and effects of the present invention. The examples are implemented based on the technical solutions of the present invention, and provide detailed implementation methods and specific operating processes, but the scope of protection of the present invention is not limited to the following examples.

[0049] In the present invention, the pore volume (mercury intrusion) of the macroporous alumina in the sub-outer layer and outer surface involved in the examples and comparative examples was tested using a PoreMaster 60GT mercury intrusion instrument from Quantachrome Instruments, USA.

[0050] In the present invention, the specific surface area of ​​the macroporous alumina in the sub-outer layer and the outer surface involved in the examples and comparative examples was measured using a Micromeritics TriStar 2420 physical adsorption analyzer from the United States.

[0051] In the present invention, the metal element contents in the solutions and catalysts in the examples and comparative examples were analyzed using an inorganic method.

[0052] Example 1

[0053] (1) Take an alumina support (the pore volume of the support is 0.76 cm 3 / g, specific surface area is 166m 2 / g) 200g, prepare 220ml of molybdenum-nickel impregnation solution R1, wherein the content of MoO3 is 9.4g / 100ml and the content of NiO is 2.0g / 100ml, impregnate the support with active metal impregnation solution R1 (the amount of R1 is 1.1 times the saturated water absorption rate of the support), and dry at 110°C for 5 hours to obtain a catalyst body;

[0054] (2) 1.5L of aluminum sulfate aqueous solution (with a concentration of 9.6g / 100mL based on Al2O3 and an initial temperature of 85°C) was introduced from the top into a reactor equipped with 5L of purified water, a stirrer and a heating jacket, and 1L of sodium metaaluminate aqueous solution (with a concentration of 34g / 100mL based on Al2O3 and an initial temperature of 90°C) was introduced from the bottom of the reactor. The neutralization reaction temperature was controlled at 100°C. Aluminum sulfate solution and sodium metaaluminate solution were added continuously, and the pH value was controlled at 8.3. After the parallel flow is completed, the first stage of aging is carried out, the aging temperature is 140°C, the aging time is 120 minutes, and the aging pH value is 9.2; after the first stage of aging is completed, the slurry volume is concentrated to 5L, 110g of polyvinyl alcohol is added, and the viscosity of the system after addition (20°C) is 290mPa·s, the temperature is raised to 175°C, and the second stage of aging is carried out for 120 minutes, washed, filtered, and slurried with clean water to obtain a macroporous pseudo-boehmite slurry with an alumina content of 21g / L.

[0055] (3) The macroporous pseudo-boehmite slurry and the active metal impregnation solution R1 are mixed in proportion to obtain the active metal impregnation solution R2, wherein the mass of the molybdenum oxide provided in the active metal impregnation solution R1 accounts for 4.31% of the total mass of the aluminum oxide provided in the macroporous pseudo-boehmite slurry and the metal oxide provided in the active metal impregnation solution R1, and the mass of the nickel oxide provided in the active metal impregnation solution R1 accounts for 0.91% of the total mass of the aluminum oxide provided in the macroporous pseudo-boehmite slurry and the metal oxide provided in the active metal impregnation solution R1.

[0056] (4) Prepare the binder solution: Dissolve 20 g of starch in 400 g of pure water under heating and stirring conditions, stirring until uniformly dissolved. Immerse the catalyst body particles in the binder for 10 seconds, remove them, drain off the excess binder solution, and allow them to stand at room temperature for 30 minutes. Next, add them to the active metal impregnation solution R2, stir them, and soak them for 1 minute. After the surface is coated with the impregnation solution R2, remove them, centrifuge them in a high-speed centrifuge for 5 minutes, and dry them at 120°C for 5 hours to obtain the catalyst body.

[0057] (5) The catalyst intermediate obtained in step (4) was added to the pseudo-boehmite slurry and stirred. The mixture was allowed to soak for 1 minute. After the surface was coated with the slurry, the mixture was taken out and centrifuged in a high-speed centrifuge for 5 minutes. The mixture was then dried at 120°C for 5 hours. The temperature was then raised to 550°C at a heating rate of 2°C / min and calcined for 4 hours to obtain a residue hydrodemetallization catalyst A.

[0058] Example 2

[0059] The same method as Example 1 is described except that in step (3), when preparing the active metal impregnation solution R2, the mass of the molybdenum oxide provided in the active metal impregnation solution R1 accounts for 3.16% of the total mass of the aluminum oxide provided in the macroporous pseudo-boehmite slurry and the metal oxide provided in the active metal impregnation solution R1, and the mass of the nickel oxide provided in the active metal impregnation solution R1 accounts for 0.66% of the total mass of the aluminum oxide provided in the macroporous pseudo-boehmite slurry and the metal oxide provided in the active metal impregnation solution R1. In step (4), the catalyst body is coated with the impregnation solution R2, removed, and centrifuged in a high-speed centrifuge for 7 minutes to obtain a residue oil hydrodemetallization catalyst B.

[0060] Example 3

[0061] The same method as Example 1 is described except that in step (3), when preparing the active metal impregnation solution R2, the mass of the molybdenum oxide provided in the active metal impregnation solution R1 accounts for 2.51% of the total mass of the aluminum oxide provided in the macroporous pseudo-boehmite slurry and the metal oxide provided in the active metal impregnation solution R1, and the mass of the nickel oxide provided in the active metal impregnation solution R1 accounts for 0.52% of the total mass of the aluminum oxide provided in the macroporous pseudo-boehmite slurry and the metal oxide provided in the active metal impregnation solution R1. In step (4), after the surface of the catalyst body is coated with the impregnation solution R2, it is removed and centrifuged in a high-speed centrifuge for 3 minutes to obtain a residue oil hydrodemetallization catalyst C.

[0062] Example 4

[0063] The same as Example 1, except that in step (4), the catalyst body is coated with the impregnation liquid R2 and then taken out and centrifuged in a high-speed centrifuge for 2 minutes. In step (5), the catalyst intermediate is added to the macroporous pseudo-boehmite slurry and stirred. The soaking time is 2 minutes, and the catalyst is centrifuged in a high-speed centrifuge for 5 minutes to obtain the residue oil hydrodemetallization catalyst D.

[0064] Example 5

[0065] The same method as Example 1 is described except that in step (3), when preparing the active metal impregnation solution R2, the mass of the molybdenum oxide provided in the active metal impregnation solution R1 accounts for 2.15% of the total mass of the aluminum oxide provided in the macroporous pseudo-boehmite slurry and the metal oxide provided in the active metal impregnation solution R1, and the mass of the nickel oxide provided in the active metal impregnation solution R1 accounts for 0.44% of the total mass of the aluminum oxide provided in the macroporous pseudo-boehmite slurry and the metal oxide provided in the active metal impregnation solution R1. In step (5), the catalyst intermediate is added to the macroporous pseudo-boehmite slurry with stirring, soaked for 1 minute, and centrifuged in a high-speed centrifuge for 8 minutes to obtain the residue oil hydrodemetallization catalyst E.

[0066] Comparative Example 1

[0067] The same as Example 1, except that after drying in step (1), steps (2) to (5) are omitted, and the catalyst is directly calcined at 550°C for 4 hours to obtain the residue hydrodemetallization catalyst F. The pore volume of catalyst F is 0.66 cm 3 / g, specific surface area of ​​137m 2 / g, the mass content of MoO3 is 9.00%, and the mass content of NiO is 1.90%.

[0068] Comparative Example 2

[0069] The same method as Example 1 was used, except that in step (3), when preparing the active metal impregnation solution R2, the mass of the molybdenum oxide provided in the active metal impregnation solution R1 accounted for 9.01% of the total mass of the aluminum oxide provided in the macroporous pseudo-boehmite slurry and the metal oxide provided in the active metal impregnation solution R1, and the mass of the nickel oxide provided in the active metal impregnation solution R1 accounted for 1.92% of the total mass of the aluminum oxide provided in the macroporous pseudo-boehmite slurry and the metal oxide provided in the active metal impregnation solution R1. Thus, a residue oil hydrodemetallization catalyst G was obtained.

[0070] Table 1 Properties of the catalysts obtained in each example

[0071]

[0072] Evaluation test

[0073] The activity and stability of catalysts A and B were evaluated in a 200 ml fixed-bed hydrogenation test apparatus. The properties of the feed oil are listed in Table 2, the experimental conditions are listed in Table 3, and the removal rate of catalyst F after 100 hours of operation is used as a benchmark. The experimental results are listed in Table 4.

[0074] Table 2 Properties of crude oil

[0075] Raw oil properties Middle East residual oil S, wt% 3.7 Ni, μg / g 32.8 CCR, wt% 10.52 V, μg / g 86.5

[0076] Table 3 Test conditions

[0077] Reaction temperature, °C 375 Reaction pressure, MPa 15.0 <![CDATA[Space velocity, h -1 > 1.0 Hydrogen to oil ratio, V / V 600

[0078] Table 4 Evaluation results of the catalysts obtained in each case

[0079]

[0080] As can be seen from Table 4, the hydrodemetallization catalyst prepared in the present invention has better demetallization performance than the comparative agent, and has excellent resistance to carbon deposition and metal deposition, and has good stability, which provides a technical guarantee for extending the operation cycle of the device.

Claims

1. A residue hydrodemetallization catalyst, comprising a catalyst body composed of a carrier and an active metal, a secondary outer layer, and a macroporous alumina layer, wherein the secondary outer layer comprises macroporous alumina and the active metal; the active metal comprises molybdenum and nickel; the thickness ratio of the macroporous alumina layer to the secondary outer layer is 3:5 to 3:2, and the thickness of the macroporous alumina layer is 50 to 100 μm; In the catalyst, based on the mass of the catalyst, the molybdenum oxide content is 3.00% to 13.90%, and the nickel oxide content is 0.50% to 3.50%; Based on the total molybdenum oxide loading in the catalyst, the content of molybdenum oxide in the sub-outer layer is 0.52% to 0.19%; Based on the total nickel oxide loading in the catalyst, the nickel oxide content in the sub-outer layer is 0.51% to 1.18%; The pore volume of the secondary outer layer is 0.80~1.25cm 3 / g; The pore volume of the macroporous alumina layer is 0.90-1.25 cm 3 / g; The pore volume of the carrier is 0.65~1.25cm 3 / g.

2. The catalyst according to claim 1, characterized in that The specific surface area of ​​the secondary outer layer is 160~240m 2 / g.

3. The catalyst according to claim 1, characterized in that The specific surface area of ​​the macroporous alumina layer is 160-260 m 2 / g.

4. The catalyst according to claim 1, characterized in that The carrier is an alumina-based carrier with a pore volume of 0.70-1.20 cm 3 / g, with a specific surface area of ​​100~240m 2 / g.

5. The method for preparing the residue hydrodemetallization catalyst according to any one of claims 1 to 4, comprising the steps of: (1) impregnating the support with active metal impregnation solution R1 and drying to obtain the catalyst body; (2) Preparation of macroporous pseudo-boehmite slurry: (3) mixing the macroporous pseudo-boehmite slurry obtained in step (2) with the active metal impregnation solution R1 in a certain proportion to obtain the active metal impregnation solution R2; (4) using the active metal impregnation solution R2 obtained in step (3) to wrap the catalyst body obtained in step (1), and drying it to obtain a catalyst intermediate; (5) The catalyst intermediate obtained in step (4) is impregnated with the macroporous pseudo-boehmite slurry prepared in step (2), dried, and calcined to obtain the residual oil hydrodemetallization catalyst.

6. The preparation method according to claim 5, characterized in that The amount of active metal impregnation solution R1 used in step (1) is 1.05 to 1.25 times the saturated water absorption rate of the carrier.

7. The preparation method according to claim 5, characterized in that The content of MoO3 in the active metal impregnation solution R1 is 3.00~14.00g / 100mL, and the content of NiO is 0.50~3.50g / 100mL.

8. The preparation method according to claim 5, characterized in that The alumina content in the macroporous pseudo-boehmite slurry in step (2) is 10-100 g / L.

9. The preparation method according to claim 5, characterized in that In step (3), the mass of molybdenum oxide provided in the active metal impregnation solution R1 accounts for 0.15% to 11.12% of the total mass of aluminum oxide provided in the macroporous pseudo-boehmite slurry and the metal oxide provided in the active metal impregnation solution R1, and the mass of nickel oxide provided in the active metal impregnation solution R1 accounts for 0.02% to 2.78% of the total mass of aluminum oxide provided in the macroporous pseudo-boehmite slurry and the metal oxide provided in the active metal impregnation solution R1.

10. The preparation method according to claim 5, characterized in that In step (4), the catalyst body obtained in step (1) is added to the active metal impregnation solution R2 obtained in step (3) and stirred. The immersion time is 3s to 20min. After the surface is coated with the impregnation solution R2, it is taken out and centrifuged to remove excess solution on the surface. The centrifugation time is 1 to 20min, and then dried at 100 to 160°C for 2 to 12 hours.

11. The preparation method according to claim 5, characterized in that In step (4), before the active metal impregnation solution R2 obtained in step (3) is used to wrap the catalyst body obtained in step (1), the catalyst body is first immersed in a binder solution for 5 to 60 seconds.

12. The preparation method according to claim 11, characterized in that The adhesive is one or more of starch, dextrin, polyvinyl alcohol or carboxymethyl cellulose, and the mass content of the adhesive in the adhesive solution is 1% to 80%.

13. The preparation method according to claim 11, characterized in that The mass content of the adhesive in the adhesive solution is 2% to 20%.

14. The preparation method according to claim 5, characterized in that In step (5), the catalyst intermediate obtained in step (4) is added to the macroporous pseudo-boehmite slurry obtained in step (2) and stirred. The soaking time is 2s to 20min. After the surface is coated with the macroporous pseudo-boehmite slurry, it is taken out and centrifuged to remove excess slurry on the surface. The centrifugation time is 1 to 20min, and then dried at 100 to 160°C for 2 to 12 hours.

15. The preparation method according to claim 5, characterized in that The calcination conditions in step (5) are: calcination at 450-600° C. for 2-6 hours, and the calcination is carried out in an oxygen-containing atmosphere.

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