Hydrotreating catalyst as well as preparation method and application thereof

Abstract

The invention discloses a hydrotreating catalyst as well as a preparation method and application thereof. The method comprises the following steps: impregnating an alumina-based carrier in an impregnation liquid containing dopamine, a protective agent and hydrogenation active metal in a supersaturated manner, adjusting the pH value of the system to enable the dopamine to be self-polymerized on the surface of a pore channel of the alumina-based carrier, and then washing, drying, pre-depositing carbon and roasting to obtain the hydrotreating catalyst. The hydrogenation catalyst prepared by the method provided by the invention has obviously improved desulfurization and denitrification activity and stability.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalysis, and in particular relates to a hydroprocessing catalyst and a preparation method and application thereof. Background Art

[0002] Most supported catalysts, such as various hydrogenation catalysts, are prepared using the impregnation method. When using this method to prepare hydrogenation catalysts, the catalytic activity is closely related to the dispersion of the active metal (such as Mo) on the surface and its interaction with the support (such as alumina). Improving the dispersion of the active metal on the support surface while simultaneously reducing the strong metal-support interaction is crucial for preparing highly active hydrogenation catalysts.

[0003] CN106669786A discloses a catalytic diesel hydrocracking catalyst and a preparation method thereof. The catalyst carrier is prepared by mixing modified molecular sieves, amorphous silica-alumina and / or alumina. Unsaturated olefins are then impregnated or adsorbed onto the carrier, carbonized by reaction under an inert atmosphere, and partially carbonized by calcination. The carbon-containing carrier is then obtained by loading active metals and drying to obtain the catalyst.

[0004] CN 101940930A discloses a method for preparing a hydroprocessing catalyst, which mainly comprises impregnating a catalyst precursor with a carbon-containing precursor, introducing a mixture of organic matter, soluble silicone oil, and an additive into a carrier, and then heat-treating the carrier to obtain a carbon-modified alumina carrier.

[0005] CN101940929A discloses a method for preparing a hydroprocessing catalyst. This method involves adding a carbon precursor to a metal impregnation solution to introduce a carbon source and an active metal into the catalyst in one step. By controlling the heating rate during carbonization and roasting to prevent the large-scale volatilization of organic matter, carbon deposition in the catalyst is achieved.

[0006] The above preparation methods all introduce carbon-containing organic matter onto the carrier or catalyst and then perform a carbonization process to cover the acid center, but fail to achieve a reasonable distribution of carbon, active components, and acid sites. Summary of the Invention

[0007] In order to overcome the deficiencies in the prior art, the present invention provides a hydroprocessing catalyst and its preparation method and application. The hydroprocessing catalyst prepared by the method of the present invention has significantly improved desulfurization and denitrification activities.

[0008] A first aspect of the present invention provides a method for preparing a hydroprocessing catalyst, comprising:

[0009] The alumina-based carrier is supersaturatedly immersed in an impregnation solution containing dopamine, a protective agent and a hydrogenation active metal, and the pH value of the system is adjusted to allow dopamine to self-polymerize on the surface of the alumina-based carrier pores. The catalyst is then washed, dried, pre-carbonized and calcined to obtain a hydrogenation treatment catalyst.

[0010] In the method of the present invention, the alumina-based carrier can be a commercially available product or prepared according to conventional methods. The preparation method of the alumina-based carrier can be as follows: mixing and kneading aluminum hydroxide dry rubber powder, shaping it, and then drying and calcining it to form the alumina-based carrier. During the kneading process, conventional molding aids such as extrusion aids, binders, and peptizers can be added as needed. The alumina-based carrier can contain auxiliary components, such as at least one of silicon, phosphorus, titanium, zirconium, magnesium, etc., and the weight content of the auxiliary components in the carrier is less than 15%.

[0011] In the method of the present invention, the pore volume of the alumina-based carrier is 0.3-1.5 mL / g, and the specific surface area is 150-450 m 2 / g.

[0012] In the method of the present invention, the shape of the alumina-based carrier can be spherical, bar-shaped (cylindrical, butterfly-shaped, clover-shaped or four-leaf clover-shaped bar), etc. The shape of the carrier can be selected according to specific needs.

[0013] In the method of the present invention, the amount of dopamine added to the impregnation solution is 2 wt% to 40 wt%, preferably 4 wt% to 24 wt%, based on the mass of the alumina-based support. The solvent used in the solution containing dopamine, a protective agent, and a hydrogenation-active metal is at least one of water, methanol, or ethanol.

[0014] In the method of the present invention, the protective agent is a water-soluble olefin, preferably one or more of N-isopropylacrylamide sodium styrene sulfonate, sodium methallyl sulfonate, sodium allyl sulfonate, isopentenol, 3-methyl-3-butene-1-ol, allyl alcohol, etc., and more preferably one or more of N-isopropylacrylamide sodium styrene sulfonate, sodium methallyl sulfonate, and sodium allyl sulfonate.

[0015] In the method of the present invention, the amount of the protective agent added to the impregnation solution accounts for 0.5 wt% to 8 wt%, preferably 1 wt% to 5 wt%, of the alumina-based support.

[0016] In the method of the present invention, the hydrogenation-active metal includes Group VIII metals and Group VIB metals, wherein the Group VIII metal is preferably Ni and / or Co, and the Group VIB metal is preferably Mo. When preparing the impregnation solution, the molybdenum source that can be used is selected from one or more of molybdenum oxide, ammonium molybdate, ammonium tetrathiomolybdate, and ammonium paramolybdate; the nickel source is selected from one or more of nickel nitrate, basic nickel carbonate, nickel oxalate, nickel chloride, and nickel acetate; and the cobalt source is selected from one or more of cobalt nitrate, cobalt oxalate, basic cobalt carbonate, and cobalt chlorate.

[0017] In the method of the present invention, the amount of hydrogenation active metal added to the impregnation solution in terms of oxide is 12 wt% to 36 wt%, preferably 18 wt% to 32 wt%, based on the mass of the alumina-based support.

[0018] In the method of the present invention, the impregnation solution may further contain an auxiliary component. The auxiliary component may be selected from one or more of phosphorus, titanium, silicon, zinc, copper, zirconium, boron, fluorine, lanthanum, cerium, and vanadium. The auxiliary component is added to the impregnation solution in an amount of 0.5 wt% to 5 wt%, preferably 1 wt% to 3 wt%, based on the alumina-based support.

[0019] In the method of the present invention, the impregnation adopts supersaturated impregnation, wherein the volume of the impregnation liquid is 1.5 to 4.5 times, preferably 1.8 to 4.0 times, the saturated water absorption capacity of the alumina-based support.

[0020] In the method of the present invention, the immersion temperature is 10 to 80° C., preferably 30 to 60° C., and the immersion time is 1 to 30 hours, preferably 5 to 20 hours.

[0021] In the method of the present invention, the reagent for adjusting the pH value of the system is selected from one or more of ethylenediamine, ammonium carbonate, diethanolamine, triethanolamine, and Tris buffer.

[0022] In the method of the present invention, the pH value of the system is adjusted by immersing the carrier in the impregnation solution, shaking for 5-10 minutes, adding a pH adjusting agent to the system, and continuing to shake until the pH value of the system reaches 8 to 10. The pH value of the system after adding the pH adjusting agent is at least 0.5 higher than the pH value before adding the pH adjusting agent.

[0023] In the method of the present invention, the drying process is to impregnate the carrier with the impregnation liquid and dry it under conditions not exceeding the decomposition temperature of the generated polydopamine. The drying temperature is generally 30°C to 180°C, preferably 50 to 120°C; the drying time is 0.5h to 20h, preferably 2 to 10h.

[0024] In the method of the present invention, the pre-coking is carried out under an inert atmosphere, preferably nitrogen. The pre-coking reaction conditions are: a reaction temperature of 200-500°C, preferably 250-350°C, and a reaction time of 1-5 hours, preferably 2-4 hours. Furthermore, the carbon content of the catalyst after pre-coking is 0.5-5% by weight, preferably 2.5-4.0% by weight.

[0025] In the method of the present invention, the calcination is carried out in an oxygen-containing atmosphere. The oxygen-containing atmosphere is selected from the group consisting of air, a mixture of oxygen and nitrogen, or a mixture of oxygen and an inert gas. The volume fraction of oxygen in the oxygen-containing mixture is 10% to 50%, preferably 15% to 45%. The calcination conditions are as follows: a calcination temperature of 400°C to 600°C and a calcination time of 0.5 to 6 hours, preferably 1 to 3 hours.

[0026] The hydroprocessing catalyst prepared by the method of the present invention employs an alumina-based support and contains Group VIII and Group VIB metals as hydrogenation-active metal components. The Group VIII metal is preferably Co and / or Ni, and the Group VIB metal is preferably Mo. The content of the Group VIII metal as oxide is 1 wt% to 10 wt%, preferably 2 wt% to 8 wt%, based on the mass of the alumina-based support. The content of the Group VIB metal as oxide is 10 wt% to 25 wt%, preferably 15 wt% to 23 wt%.

[0027] The second aspect of the present invention provides a hydroprocessing catalyst prepared by the above method.

[0028] The third aspect of the present invention provides the use of the hydroprocessing catalyst prepared by the above method in the hydroprocessing of heavy distillate oil.

[0029] Furthermore, the distillation range of the heavy distillate oil raw material is 270-580° C., and the heavy distillate oil raw material is at least one of coker wax oil, vacuum gas oil, deasphalted oil, catalytic cracking cycle oil, shale oil and coal tar.

[0030] Furthermore, the hydrotreatment conditions are: reaction temperature of 350-430°C, preferably 360-390°C, reaction pressure of 4-16 MPa, preferably 6-14 MPa, and hydrogen-to-oil volume ratio of 600:1-1500:1, preferably 800:1-1000:1.

[0031] Furthermore, the purpose of the hydrotreatment is hydrodesulfurization and / or hydrodenitrogenation.

[0032] Compared with the prior art, the present invention has the following advantages:

[0033] The present invention first modifies the surface of the alumina-based carrier with dopamine and a protective agent, and then adjusts the pH value of the solution to induce dopamine to self-polymerize on the carrier surface to form polydopamine, effectively blocking the direct interaction between the hydrogenation active metal and the carrier, and forming a "network" structure on the carrier surface that is conducive to efficient dispersion and anchoring of active components, thereby effectively "anchoring" the hydrogenation active metal and avoiding the flow and aggregation of the hydrogenation active metal; the protective agent introduced at the same time as dopamine can cover part of the acidic site before dopamine polymerization, avoiding the covering of the active component when "anchoring" the metal. The catalyst can also prevent excessive polymerization of dopamine and ensure the permeability of the catalyst pores; the inert gas pre-carbon deposition method is adopted to make the polydopamine partially carbonized and anchor the hydrogenation active metal components, effectively preventing the aggregation of active components; and then undergo high-temperature calcination to burn off the protective agent, remaining polydopamine and part of the carbon deposits deposited on the medium-strong acid sites, which not only effectively disperses the hydrogenation active metals but also retains the medium-strong acid on the catalyst surface, realizes the effective matching of the acid center and the hydrogenation center, and is beneficial to improve the hydrodesulfurization and hydrodenitrogenation activities of the catalyst. DETAILED DESCRIPTION

[0034] The present invention is described in detail below by way of examples, but the present invention is not limited to the following examples. In addition, % in the present invention is by weight unless otherwise specified.

[0035] In the present invention, the properties of the alumina carrier used in the examples and comparative examples are as follows: pore volume of 0.85 mL / g, specific surface area of ​​213 m 2 / g.

[0036] In the present invention, the preparation process of the impregnation solution is as follows: (1) preparing an aqueous solution of active metal components with basic nickel carbonate, molybdenum oxide, and phosphoric acid; (2) adding dopamine and a protective agent to the aqueous solution of the active metal components to obtain the impregnation solution.

[0037] Example 1

[0038] (1) 200 mL of an impregnation solution containing Mo, Ni, P, 4 g of dopamine, and 1 g of propylene alcohol was prepared. The active metal components (calculated as oxides) in the impregnation solution were 20 wt % Mo and 4 wt % Ni, based on the mass of the alumina-based support. The pH of the impregnation solution was 6.0.

[0039] (2) 100 g of alumina support was added to the impregnation solution, and after shaking for 5 min, ethylenediamine was added to adjust the solution pH to about 8.0. The solution was impregnated at 30° C. for 20 h, and then dried at 80° C. for 6 h to obtain a catalyst precursor.

[0040] (3) The catalyst precursor obtained in step (2) was placed in a calciner, nitrogen was introduced into the calciner, and the product was calcined at 350°C for 2 hours to pre-coke. An oxygen / nitrogen mixture with an oxygen content of 25% was then introduced into the calciner, and the product was calcined at 450°C for 3 hours to obtain Catalyst C1 of the present invention. The carbon content of the catalyst after pre-coking was 2.6 wt%.

[0041] Example 2

[0042] (1) 300 mL of an impregnation solution containing Mo, Ni, P, 30 g of dopamine, and 5 g of sodium methyl allyl sulfonate was prepared. The active metal components (calculated as oxides) in the impregnation solution were 20 wt % Mo and 4 wt % Ni, based on the mass of the alumina-based support. The pH of the impregnation solution was 8.0.

[0043] (2) 100 g of alumina support was added to the impregnation solution, and diethanolamine was added after shaking for 5 minutes to adjust the solution pH to about 9. The solution was immersed at 50° C. for 6 hours, and then dried at 120° C. for 3 hours to obtain a catalyst precursor.

[0044] (3) The catalyst precursor obtained in step (2) was placed in a calciner, nitrogen was introduced into the calciner, and the product was calcined at 300°C for 3 hours to pre-coke. An oxygen / nitrogen mixture with an oxygen content of 10% was then introduced into the calciner, and the product was calcined at 450°C for 3 hours to obtain catalyst C2 of the present invention. The carbon content of the catalyst after pre-coking was 4.5 wt%.

[0045] Example 3

[0046] (1) 400 mL of an impregnation solution containing Mo, Ni, P, 20 g of dopamine, and 4 g of sodium N-isopropylacrylamide-p-styrenesulfonate was prepared. The active metal components (calculated as oxides) in the impregnation solution were 20 wt % Mo and 4 wt % Ni, based on the mass of the alumina-based support. The pH of the impregnation solution was 7.5.

[0047] (2) 100 g of alumina support was added to the impregnation solution, shaken for 5 min, and then Tris buffer was added to adjust the solution pH to about 8.5. The solution was immersed at 40° C. for 10 h, and then dried at 100° C. for 4 h to obtain a catalyst precursor.

[0048] (3) The catalyst precursor obtained in step (2) was placed in a calciner, nitrogen was introduced into the calciner, and the product was calcined at 350°C for 4 hours to pre-coke. An oxygen / nitrogen mixture with an oxygen content of 25% was then introduced into the calciner, and the product was calcined at 450°C for 3 hours to obtain the catalyst C3 of the present invention. The carbon content of the catalyst after pre-coking was 3.4 wt%.

[0049] Example 4

[0050] (1) 250 mL of an impregnation solution containing Mo, Ni, P, 5 g of dopamine, and 3 g of prenol was prepared. The active metal components (calculated as oxides) in the impregnation solution were 20 wt % Mo and 4 wt % Ni, based on the mass of the alumina-based support. The pH of the impregnation solution was 7.0.

[0051] (2) 100 g of alumina support was added to the impregnation solution, shaken for 5 min, and then Tris buffer was added to adjust the solution pH to about 8.5. The solution was immersed at 30° C. for 15 h, and then dried at 120° C. for 4 h to obtain a catalyst precursor.

[0052] (3) The catalyst precursor obtained in step (2) was placed in a calciner, nitrogen was introduced into the calciner, and the catalyst was calcined at 200°C for 3 hours to pre-coke. Then, an oxygen / nitrogen mixture with an oxygen content of 25% was introduced into the calciner, and the catalyst was calcined at 450°C for 3 hours to obtain the catalyst C4 of the present invention. The carbon content of the catalyst after pre-coking was 3 wt%.

[0053] Example 5

[0054] (1) 300 mL of an impregnation solution containing Mo, Ni, P, 18 g of dopamine, and 5 g of sodium allyl sulfonate was prepared. The active metal components (calculated as oxides) in the impregnation solution were 20 wt % Mo and 4 wt % Ni, based on the mass of the alumina-based support. The pH of the impregnation solution was 8.0.

[0055] (2) 100 g of alumina support was added to the impregnation solution, shaken for 5 min, and then diethanolamine was added to adjust the solution pH to about 9.5. The solution was immersed at 60° C. for 20 h, and then dried at 110° C. for 6 h to obtain a catalyst precursor.

[0056] (3) The catalyst precursor obtained in step (2) was placed in a calciner, nitrogen was introduced into the calciner, and the catalyst was calcined at 300°C for 4 hours to pre-coke. Then, an oxygen / nitrogen mixture with an oxygen content of 25% was introduced into the calciner, and the catalyst was calcined at 450°C for 3 hours to obtain catalyst C5 of the present invention. The carbon content of the catalyst after pre-coking was 3.8 wt%.

[0057] Comparative Example 1

[0058] (1) An aqueous solution of nickel nitrate, ammonium molybdate, and phosphoric acid was prepared as an impregnation solution. The active metal components (calculated as oxides) in the impregnation solution were 20 wt% Mo and 4 wt% Ni, based on the mass of the alumina-based support. Equal volumes of 100 g of the support were impregnated, dried at 120°C for 4 hours, and calcined at 300°C for 4 hours by passing nitrogen through a calcination furnace. An oxygen / nitrogen mixture with an oxygen content of 25% was then passed through the calcination furnace and calcined at 450°C for 3 hours to obtain comparative catalyst DC1.

[0059] Comparative Example 2

[0060] (1) 300 mL of an impregnation solution containing Mo, Ni, P, and 18 g of dopamine was prepared. The active metal components (calculated as oxides) in the impregnation solution were 20 wt % Mo and 4 wt % Ni, based on the mass of the alumina-based support. The pH of the impregnation solution was 5.5.

[0061] (2) 100 g of alumina support was added to the impregnation solution, aged for 12 h in a water vapor saturated atmosphere, and then vacuum dried at 40° C. for 2 h to obtain a catalyst precursor.

[0062] (3) The catalyst precursor obtained in step (2) was placed in a calciner, nitrogen was introduced into the calciner, and the catalyst was calcined at 300°C for 4 hours to pre-coke. An oxygen / nitrogen mixture with an oxygen content of 25% was then introduced into the calciner, and the catalyst was calcined at 450°C for 3 hours to obtain a comparative catalyst DC2. The carbon content of the catalyst after pre-coking was 2.2%.

[0063] Comparative Example 3

[0064] Compared with Example 5, sodium allyl sulfonate was not added to prepare the impregnation solution, thereby obtaining comparative catalyst DC3.

[0065] (1) 300 mL of an impregnation solution containing Mo, Ni, P, and 18 g of dopamine was prepared; in the impregnation solution, the active metal component (calculated as oxide) Mo content was 20 wt % and Ni content was 4 wt % based on the mass of the alumina-based support.

[0066] (2) 100 g of alumina support was added to the impregnation solution, shaken for 5 min, and then diethanolamine was added to adjust the solution pH to about 9.5. The solution was immersed at 60° C. for 20 h, and then dried at 110° C. for 6 h to obtain a catalyst precursor.

[0067] (3) The catalyst precursor obtained in step (2) was placed in a calciner, nitrogen was introduced into the calciner, and the catalyst was calcined at 300°C for 4 hours to pre-coke. An oxygen / nitrogen mixture with an oxygen content of 25% was then introduced into the calciner and calcined at 450°C for 3 hours to obtain a comparative catalyst DC3. The carbon content of the catalyst after pre-coking was 4.1 wt%.

[0068] Comparative Example 4

[0069] Compared with Example 5, without adding diethanolamine, the pH value was adjusted as follows:

[0070] (1) 300 mL of an impregnation solution containing Mo, Ni, P, 18 g of dopamine, and 5 g of sodium allyl sulfonate was prepared. The active metal components (calculated as oxides) in the impregnation solution were 20 wt % Mo and 4 wt % Ni, based on the mass of the alumina-based support. The pH of the impregnation solution was 8.0.

[0071] (2) 100 g of alumina support was added to the impregnation solution, impregnated at 60° C. for 20 h, and then dried at 110° C. for 6 h to obtain a catalyst precursor.

[0072] (3) The catalyst precursor obtained in step (2) was placed in a calciner, nitrogen was introduced into the calciner, and the catalyst was calcined at 300°C for 4 hours to pre-coke. An oxygen / nitrogen mixture with an oxygen content of 25% was then introduced into the calciner, and the catalyst was calcined at 450°C for 3 hours to obtain a comparative catalyst DC4. The carbon content of the catalyst after pre-coking was 2.1% by weight.

[0073] Example 6

[0074] The catalysts of the above examples and comparative examples were subjected to activity evaluation tests in a microreactor. Prior to evaluation, the hydroprocessing catalysts were treated with a cyclohexane solution of CS2 as the sulfiding solution. The cyclohexane solution had a CS2 concentration of 4 wt%, a sulfiding temperature of 330°C, a sulfiding pressure of 14.0 MPa, a sulfiding time of 6 hours, and a hydrogen to sulfiding solution volume ratio of 5:5.

[0075] The raw oil is catalytic diesel, the properties of which are shown in Table 1. The reaction hydrogen pressure is 14.0 MPa, the hydrogen-to-oil volume ratio is 1000:1, and the volume space velocity is 1.0 h -1 , the reaction temperature is 370℃.

[0076] Table 1 Properties of crude oil

[0077] <![CDATA[Density (20 °C) / g·cm -3 > 0.9267 Distillation range / ℃ IBP / 10% 276 / 364 30％ / 50％ 407 / 428 70％ / 90％ 473 / 529 95% / EBP 553 / 575 <![CDATA[S / μg·g -1 ]]> 29600 <![CDATA[N / μg·g -1 ]]> 1540

[0078] The hydrodesulfurization and denitrification activities of the catalyst are expressed as the hydrodesulfurization and denitrification activities relative to the reference agent (Comparative Example 1), and the relative hydrodesulfurization activity (RVA(S)) and relative hydrodenitrogenation activity (RVA(N)) of the catalyst are calculated according to formula (1) and formula (2), respectively:

[0079]

[0080]

[0081] Wherein, k(S) and k(N) represent the hydrodesulfurization and hydrodenitrogenation activities of the catalyst, respectively; k(DS) and k(DN) represent the hydrodesulfurization and hydrodenitrogenation activities of the reference agent (Comparative Example 1), respectively.

[0082] Wherein, Ssp is the sulfur content in the reaction product of the evaluation catalyst used; Ssf is the sulfur content in the reaction raw materials used; Sdp is the sulfur content in the reaction product of the reference agent; Nsp is the nitrogen content in the reaction product of the evaluation catalyst used; Nsf is the nitrogen content in the reaction raw materials used; Ndp is the nitrogen content in the reaction product of the reference agent, where the sulfur content and nitrogen content are expressed in mass fraction.

[0083] The hydrorefining evaluation results of the catalysts prepared in each embodiment and comparative example are shown in Table 2.

[0084] Table 2 Evaluation results

[0085]

[0086] As can be seen from Table 2, compared with the comparative example catalyst, the hydroprocessing catalyst prepared by the method of the present invention has higher hydrodesulfurization and denitrification activities, and is particularly suitable for the hydroprocessing process of heavy feedstocks.

Claims

1. A method for preparing a hydroprocessing catalyst, comprising: The alumina-based carrier is supersaturatedly immersed in an impregnation solution containing dopamine, a protective agent and a hydrogenation active metal, and the pH value of the system is adjusted to allow dopamine to self-polymerize on the surface of the alumina-based carrier pores. The catalyst is then washed, dried, pre-carbonized and calcined to obtain a hydrogenation treatment catalyst.

2. The preparation method according to claim 1, characterized in that The properties of the alumina-based carrier are as follows: the pore volume of the alumina-based carrier is 0.3-1.5 mL / g, the specific surface area is 150-450 m 2 / g.

3. The preparation method according to claim 1, characterized in that In the impregnation solution, the amount of dopamine added is 2 wt% to 40 wt%, preferably 4 wt% to 24 wt%, based on the mass of the alumina-based support.

4. The preparation method according to claim 1, characterized in that The protective agent is a water-soluble olefin, preferably one or more of N-isopropylacrylamide sodium styrene sulfonate, sodium methallyl sulfonate, sodium allyl sulfonate, isopentenol, 3-methyl-3-butene-1-ol, and allyl alcohol, and more preferably one or more of N-isopropylacrylamide sodium styrene sulfonate, sodium methallyl sulfonate, and sodium allyl sulfonate.

5. The preparation method according to claim 1 or 4, characterized in that In the impregnation solution, the amount of the protective agent added is 0.5 wt% to 8 wt% of the alumina-based support, preferably 1 wt% to 5 wt%.

6. The preparation method according to claim 1, characterized in that The hydrogenation active metals include Group VIII metals and Group VIB metals, wherein the Group VIII metals are preferably Ni and / or Co, and the Group VIB metals are preferably Mo.

7. The preparation method according to claim 1, characterized in that In the impregnation solution, the amount of hydrogenation active metal added in terms of oxide is 12 wt% to 36 wt%, preferably 18 wt% to 32 wt%, based on the mass of the alumina-based support.

8. The preparation method according to claim 1, characterized in that The impregnation solution also contains auxiliary components, which are selected from one or more of phosphorus, titanium, silicon, zinc, copper, zirconium, boron, fluorine, lanthanum, cerium, and vanadium. The amount of the auxiliary added to the impregnation solution accounts for 0.5wt% to 5wt% of the alumina-based carrier, preferably 1wt% to 3wt%.

9. The preparation method according to any one of claims 1 to 8, characterized in that The impregnation adopts supersaturated impregnation, wherein the volume of the impregnation liquid is 1.5 to 4.5 times, preferably 1.8 to 4.0 times, the saturated water absorption capacity of the alumina-based support.

10. The preparation method according to claim 1, characterized in that The immersion temperature is 10-80° C., preferably 30-60° C., and the immersion time is 1-30 hours, preferably 5-20 hours.

11. The preparation method according to claim 1, characterized in that The reagent for adjusting the pH value of the system is selected from one or more of ethylenediamine, ammonium carbonate, diethanolamine, triethanolamine, and Tris buffer.

12. The preparation method according to claim 1 or 11, characterized in that: The pH value of the system is adjusted by immersing the carrier in the impregnation solution, shaking for 5-10 minutes, adding a system pH adjusting agent and continuing to shake until the pH value of the system reaches 8-10; preferably, the pH value of the system after adding the pH adjusting agent is at least 0.5 higher than that before adding the pH adjusting agent.

13. The preparation method according to claim 1, characterized in that The drying process is to impregnate the carrier with the impregnation liquid and dry it under the condition of not exceeding the decomposition temperature of the generated polydopamine. Preferably, the drying temperature is 30°C to 180°C, preferably 50 to 120°C; the drying time is 0.5h to 20h, preferably 2 to 10h; And / or, the pre-carbon deposition is carried out under an inert atmosphere, preferably nitrogen; the pre-carbon deposition reaction conditions are: reaction temperature 200-500° C., preferably 250-350° C., reaction time 1-5 hours, preferably 2-4 hours; preferably, the mass content of carbon in the catalyst after pre-carbon deposition is 0.5wt%-5wt%, preferably 2.5wt%-4.0wt%; And / or, the calcination is carried out in an oxygen-containing atmosphere, and the calcination conditions are: calcination temperature of 400-600° C., calcination time of 0.5-6 h, preferably 1-3 h.

14. The preparation method according to claim 1, characterized in that The hydroprocessing catalyst prepared by the method has a content of Group VIII metal in the form of oxide of 1 wt% to 10 wt%, preferably 2 wt% to 8 wt%, based on the mass of the alumina-based carrier; and a content of Group VIB metal in the form of oxide of 10 wt% to 25 wt%, preferably 15 wt% to 23 wt%.

15. A hydroprocessing catalyst prepared by the method according to any one of claims 1 to 14.

16. Use of the hydroprocessing catalyst according to claim 15 in the hydroprocessing of heavy distillate oil, characterized in that: The purpose of the hydrotreatment is hydrodesulfurization and / or hydrodenitrogenation.

17. The use according to claim 16, characterized in that The distillation range of the heavy distillate oil raw material is 270-580° C., and the heavy distillate oil raw material is at least one of coker wax oil, vacuum gas oil, deasphalted oil, catalytic cracking cycle oil, shale oil and coal tar.

18. The use according to claim 16, characterized in that The hydrotreatment conditions are as follows: reaction temperature of 350-430° C., preferably 360-390° C., reaction pressure of 4-16 MPa, preferably 6-14 MPa, and hydrogen-to-oil volume ratio of 600:1-1500:1, preferably 800:1-1000:1.

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