Preparation method and application of hydrodenitrification catalyst

Abstract

The invention provides a preparation method and application of a hydrodenitrification catalyst, and the preparation method comprises the following steps: step 1, mixing an active component precursor, a dispersant and thiosulfate to prepare an impregnation liquid; and 2, mixing a carrier with the impregnation liquid, carrying out pressurization treatment, drying, and roasting to obtain the hydrodenitrification catalyst. The dispersion degree of metal active components of the catalyst is promoted by adding the dispersing agent, the sulfuration degree of the catalyst can be improved by adding the thiosulfate, sulfur vacancies of the catalyst are increased, then active sites for adsorbing reactant macromolecules are increased, and the hydrodenitrogenation performance of the catalyst is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of hydrogenation catalysts in the field of petroleum processing, and particularly relates to a preparation method of a hydrogenation denitrogenation catalyst. BACKGROUND

[0002] Crude oil resources are becoming increasingly heavy and poor, and the deep processing and utilization of poor crude oil has become a hot spot of current technical development. The content of sulfur, nitrogen and polycyclic aromatic hydrocarbons in poor crude oil is relatively high, and if direct catalytic cracking or hydrocracking reaction is performed, catalyst deactivation and poisoning phenomena are easily caused. The hydrogenation denitrogenation process was traditionally considered as a necessary process to achieve hydrodesulfurization reaction, rather than as a target itself. However, with the increase of nitrogen impurities in crude oil and alternative oils such as biomass oil, shale oil, coal oil, tar sand and asphalt, the importance of hydrogenation denitrogenation is becoming greater and greater.

[0003] Therefore, it has become a research hotspot to specially develop a catalyst with higher hydrogenation denitrogenation activity for the denitrogenation target.

[0004] CN100340338C discloses a hydroprocessing catalyst taking one or more of Group VIB and Group VIII metals as active metal components, which is prepared by impregnating a solution containing active components and organic additives on a support of alumina modified by silicon and titanium by co-impregnation or stepwise impregnation, and then drying at room temperature to 200 DEG C to obtain the hydroprocessing catalyst. However, the organic additive of the catalyst is mainly phosphorus, and the addition of phosphorus will cause environmental pollution and other problems, and the removal of phosphorus compounds is required in subsequent operations.

[0005] CN111715232A provides a supported hydrogenation catalyst and a preparation method and application thereof. The method comprises: dissolving a salt of an active metal component in water to obtain an impregnation solution, and impregnating a support; and performing pressure treatment on the mixture obtained after impregnation, and then drying and calcining the obtained solid to obtain the supported hydrogenation catalyst. The dispersion of the active component in the catalyst prepared by the method still needs to be further improved.

[0006] Therefore, further research on the hydrogenation denitrogenation catalyst is still needed in the art. SUMMARY

[0007] The main purpose of the present application is to provide a preparation method of a hydrogenation denitrogenation catalyst and its application, so as to overcome the defects of poor dispersion of active components and poor sulfidity of the hydrogenation denitrogenation catalyst in the prior art.

[0008] In order to achieve the above purpose, the present application provides a preparation method of a hydrogenation denitrogenation catalyst, comprising the following steps:

[0009] Step 1, mixing the active component precursor, dispersant and thiosulfate to configure an impregnation solution;

[0010] Step 2, mixing the carrier with the impregnation solution, heating and pressurizing treatment, and then drying and calcining to obtain a hydrodenitrogenation catalyst.

[0011] The preparation method of the hydrodenitrogenation catalyst, wherein the active component precursor comprises at least one of a Group VIB metal-containing compound and a Group VIII metal-containing compound.

[0012] The preparation method of the hydrodenitrogenation catalyst, wherein the Group VIB metal comprises Mo and / or W, and the Group VIII metal comprises Co and / or Ni; the active component precursor comprises a Group VIB metal-containing compound and a Group VIII metal-containing compound, the Group VIB metal-containing compound is in an amount of 1-10 times the Group VIII metal-containing compound in terms of metal.

[0013] The preparation method of the hydrodenitrogenation catalyst, wherein the dispersant comprises at least one of polyvinylpyrrolidone, polyethylene glycol and polyacrylamide; the dispersant is added in an amount of 0.1-20wt% of the hydrodenitrogenation catalyst in terms of the total mass of the hydrodenitrogenation catalyst.

[0014] The preparation method of the hydrodenitrogenation catalyst, wherein the thiosulfate is ammonium thiosulfate or sodium thiosulfate; the thiosulfate is added in an amount of 0.5-5wt% of the hydrodenitrogenation catalyst in terms of the total mass of the hydrodenitrogenation catalyst.

[0015] The preparation method of the hydrodenitrogenation catalyst, wherein the content of the active component in terms of metal is 5-25wt% in terms of the total mass of the hydrodenitrogenation catalyst.

[0016] The preparation method of the hydrodenitrogenation catalyst, wherein the heating and pressurizing treatment is to treat the mixture of the carrier and the impregnation solution at 110-200℃ and 0.2-10MPa for 1-10 hours.

[0017] The preparation method of the hydrodenitrogenation catalyst, wherein the carrier comprises at least one of alumina, silica, molecular sieve, activated carbon, titanium-aluminum oxide and titanium-silicon oxide; the content of the molecular sieve in the carrier is 5-30wt%.

[0018] The preparation method of the hydrodenitrification catalyst of the present invention includes a drying temperature of 120-150℃, a drying time of 4-10h, a calcination temperature of 200-500℃, preferably 300-400℃, a calcination time of 4-6h, and a calcination atmosphere preferably consisting of an inert gas such as nitrogen or carbon dioxide.

[0019] To achieve the above objectives, the present invention also provides the application of the hydrodenitrification catalyst obtained by the above preparation method in the hydrodenitrification treatment of distillate oil.

[0020] The beneficial effects of this invention are:

[0021] The addition of the dispersant in this invention promotes the dispersion of the active metal components of the catalyst, and the addition of thiosulfate can increase the degree of sulfidation of the catalyst, increase the number of sulfur vacancies in the catalyst, thereby increasing the number of active sites that can be used to adsorb large molecules of reactants and improving the hydrodenitrification performance of the catalyst.

[0022] Furthermore, the preparation method of this invention can obtain catalysts with high specific surface area and large pore volume without the use of precipitants or templates. Compared with catalysts prepared by conventional impregnation methods with the same active component content, the catalyst prepared by the method of this invention exhibits approximately 35% higher hydrodenitrogenation activity and hydrodenitrogenation rate.

[0023] The catalyst prepared by the method of this invention can withstand harsh conditions (temperature 340℃, space velocity 8.7h). -1 It can remove 100% of the sulfur and nitrogen from the reactants, and has good reaction performance. Detailed Implementation

[0024] The technical solution of the present invention will be described in detail below. The following embodiments are implemented under the premise of the technical solution of the present invention and a detailed implementation process is given. However, the protection scope of the present invention is not limited to the following embodiments. Structures or experimental methods that do not specify specific conditions in the following embodiments are generally performed under conventional conditions.

[0025] This invention provides a method for preparing a hydrodenitrification catalyst, comprising the following steps:

[0026] Step 1: Mix the active component precursor, dispersant and thiosulfate to prepare an impregnation solution;

[0027] Step 2: Mix the carrier with the impregnation solution, heat and pressurize under an inert atmosphere, then dry and calcine to obtain the hydrodenitrogenation catalyst.

[0028] The addition of the dispersant in this invention promotes the dispersion of the active metal components of the catalyst, and the addition of thiosulfate can increase the degree of sulfidation of the catalyst, increase the number of sulfur vacancies in the catalyst, thereby increasing the number of active sites that can be used to adsorb large molecules of reactants and improving the hydrodenitrification performance of the catalyst.

[0029] In one embodiment, the active component precursor of the present invention comprises at least one of a Group VIB metal compound and a Group VIII metal compound. The Group VIB metal is, for example, Mo or W, and the Group VIII metal is, for example, Co or Ni. In another embodiment, the active component precursor of the present invention comprises a Group VIB metal compound and a Group VIII metal compound; in other words, the active component comprises Mo and / or W, and Co and / or Ni, wherein the primary active component is Mo and / or W, and the secondary active component is Co and / or Ni. In yet another embodiment, the molar ratio of the Group VIB metal compound to the Group VIII metal compound, calculated as metal, is 1-10:1.

[0030] In one embodiment, the compound containing a Group VIB metal is a salt or acid of a Group VIB metal, and the compound containing a Group VIII metal is a salt of a Group VIII metal. In another embodiment, the molybdenum precursor is one or a combination of two or more of sodium molybdate, ammonium molybdate, molybdenum chloride, and molybdic acid; the tungsten precursor is one or a combination of two or more of ammonium metatungstate, phosphotungstic acid, and silicotungstic acid; the nickel precursor is one or a combination of two or more of nickel nitrate, basic nickel carbonate, and nickel sulfate; and the cobalt precursor is one or a combination of two or more of cobalt sulfate, cobalt carbonate, and cobalt oxalate.

[0031] In one embodiment, the dispersant of the present invention includes at least one of polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), and polyacrylamide (PAM). The amount of dispersant added is 0.1-20 wt% of the total mass of the hydrodenitrification catalyst, based on 100% of the total mass of the catalyst. Further, it can be 0.5-15 wt%, 0.5-10 wt%, 0.5-5 wt%, 0.5-4 wt%, or 0.5-3 wt%.

[0032] In one embodiment, the thiosulfate of the present invention is ammonium thiosulfate or sodium thiosulfate. Based on 100% of the total mass of the hydrodenitrogenation catalyst, the amount of thiosulfate added accounts for 0.5-5 wt% of the catalyst mass, and further, it can be 1 wt%, 2 wt%, 3 wt%, or 4 wt%. The addition of the thiosulfate of the present invention can increase the degree of sulfidation of the catalyst, increase the number of sulfur vacancies in the catalyst, and thus increase the number of active sites that can be used to adsorb large molecules of reactants, thereby improving the hydrodenitrogenation performance of the catalyst. Specifically, the catalyst prepared by the present invention mainly consists of two parts: an active component and a support. The active metal (e.g., Mo) mainly interacts strongly with the basic hydroxyl groups on the Al₂O₃ support. Since the basic hydroxyl groups readily combine with the acidic sulfate ions in the added thiosulfate, the interaction between the support and the active phase is reduced, thus promoting the sulfidation of the active metal in the catalyst and increasing the number of sulfur vacancies in the catalyst prepared by the present invention.

[0033] This invention does not specifically limit the concentration of each substance in the impregnation solution, and can be adjusted as needed. Heating and stirring can be performed during the formation of the impregnation solution to accelerate dissolution.

[0034] Step 2 involves mixing the carrier with the impregnation solution, applying pressure, and then drying and calcining to obtain the hydrodenitrification catalyst.

[0035] The carrier of the present invention may include at least one of alumina, silicon oxide, molecular sieve, activated carbon, titanium aluminum oxide, and titanium silicon oxide.

[0036] In one embodiment, the carrier of the present invention includes a molecular sieve, which accounts for 0-100 wt% (excluding 0) of the total mass of the carrier. Further, the content of molecular sieve in the carrier is 5-30 wt%. In another embodiment, the carrier of the present invention does not include a molecular sieve.

[0037] In one embodiment, based on the total mass of the hydrodenitrification catalyst as 100%, the mass content of the support is 55-90 wt%, and more preferably 65-70 wt%; the content of the active component, calculated as metal, is 5-40 wt%, and more preferably 5-25 wt%.

[0038] In one embodiment, the impregnation solution is uniformly dripped onto the carrier. The mixture of the carrier and the impregnation solution is treated at 110-200°C and 0.2-10 MPa under an inert atmosphere and under heating and pressure for 1-10 hours, wherein the heating and pressure treatment is carried out in a high-pressure reactor.

[0039] The heating and pressurizing process of this invention is a hydrothermal treatment. The pressure for the heating and pressurizing process can be provided by introducing an inert gas into the reaction vessel (e.g., a reaction kettle) or by generating steam by heating the water in the impregnation solution. Preferably, the inert gas introduced is one or a combination of two or more of nitrogen, carbon dioxide, and argon.

[0040] In one embodiment, the mixture after heating and pressurizing is dried and calcined at a temperature of 120-150°C for 4-10 hours and at a temperature of 300-400°C for 4-6 hours. The calcination atmosphere is preferably an inert gas such as nitrogen or carbon dioxide.

[0041] The hydrodenitrogenation catalyst prepared by the method of this invention can be used for hydrodenitrogenation treatment of distillate oils. Examples of distillate oils include model compounds, straight-run gasoline, straight-run diesel, coking gasoline, coking diesel, catalytic cracking gasoline, and catalytic cracking diesel. It can also be used for hydrodenitrogenation treatment of heavy oils, and is particularly suitable for deep hydrotreating to remove nitrogen-containing compounds from inferior oil products. In one embodiment, the nitrogen content in the distillate oil is 200-4000 μg / g.

[0042] This invention improves the dispersion and sulfidation of active metals by adding dispersants and thiosulfates to the metal impregnation solution, thereby enhancing the denitrification performance of the catalyst and ensuring long-term stable operation of the hydrodenitrogenation reaction. The catalyst of this invention can efficiently reduce the sulfur and nitrogen content in feedstock oils.

[0043] This invention does not particularly limit the reaction apparatus, method, or process flow for using hydrodenitrification catalysts in hydrogenation reactions; conventional hydrogenation reaction apparatus, methods, and processes in the art can be used. The hydrogenation process can be carried out in a single reactor or in multiple parallel or series reactors. In other words, the catalyst of this invention can be loaded into one or more reactors in a single process for hydrogenation treatment. Without altering existing hydrogenation processes, the catalyst of this invention exhibits superior hydrogenation performance.

[0044] The hydrodenitrification catalyst of this invention requires sulfidation before use, which can be achieved through conventional in-vessel or external pre-sulfidation. In one embodiment, the sulfidation process of this invention is as follows: the hydrodenitrification catalyst is contacted with a sulfidation liquid and hydrogen for sulfidation. Sulfidation is divided into two stages: the first stage involves heating to 150-200℃ and holding at that temperature for 1-8 hours; the second stage involves heating to 250-340℃ and holding at that temperature for 1-8 hours. In another embodiment, the heating rate in the first stage is 0.1-5.0℃ / min, and the heating rate in the second stage is 0.5-5.0℃ / min.

[0045] In one embodiment, the vulcanization method of the present invention comprises a solvent and a sulfur-containing solute. The sulfur-containing solute has a mass content of 1.0%-10.0% in the vulcanization liquid, and more preferably, 6.0%-10.0%. The solvent may be a liquid hydrocarbon. The sulfur-containing solute may be at least one of CS2, dimethyl disulfide, dimethyl sulfoxide, tetramethyl sulfoxide, dodecyl sulfide, etc.

[0046] The hydrogen gas used in this invention has a purity of not less than 90% v%. The hydrogen pressure is 1.0-20.0 MPa, more specifically, 2.0-6.0 MPa, and the hydrogen flow rate is 3.0-60.0 mL / min per gram of catalyst, more specifically, 15.0-50.0 mL / min.

[0047] In one embodiment, the operating conditions of the hydrodenitrification catalyst of the present invention in fixed-bed hydrotreating are as follows: reaction temperature of 280-340℃, reaction pressure of 3.0-10.0 MPa, hydrogen-to-oil volume ratio of 200:1-1000:1, and liquid hourly space velocity (WHSV) of 4.0-16.0 h⁻¹. -1 .

[0048] Compared to catalysts prepared by conventional impregnation methods with the same active component content, the catalyst prepared by the method of this invention exhibits a hydrodenitrogenation rate increased by approximately 35%. Compared to catalysts prepared without the addition of dispersants and thiosulfates, the catalyst of this invention shows a denitrification rate increased by approximately 20% in each reaction temperature range.

[0049] The specific technical solutions of the present invention will be further described in detail below with reference to specific embodiments, so as to make the technical solutions of the present invention easier to understand and master, but the present invention is not limited thereto. Unless otherwise specified, the experimental methods in the following embodiments are conventional methods; unless otherwise specified, the reagents and materials are all available from commercial sources.

[0050] Among them, boehmite (Shanxi Hejin Juhua Aluminum Industry, industrial grade, dry basis content 70%), citric acid (Beijing Chemical Reagent Company, chemically pure, 99.0 wt.%), guar gum powder (Tianjin Fuchen Chemical Reagent Factory, analytical grade), nickel nitrate (Aladdin Biochemical Technology Co., Ltd., 98.0 wt.%), ammonium molybdate (Tianjin Guangfu Fine Chemical Research Institute, analytical grade, 99 wt.%), n-decane (Sinopharm Chemical Reagent Co., Ltd., analytical grade, 98.0 wt.%), dibenzothiophene (Shanghai Aladdin Biochemical Technology Co., Ltd., analytical grade, 98.0 wt.%), and quinoline (Tianjin Fuchen Chemical Reagent Factory, analytical grade, 98.0 wt.%) are present. Chemical reagent factory, analytical grade), carbon disulfide (Tianjin Guangfu Fine Chemical Research Institute, analytical grade, 99.0 wt.%), ammonium thiosulfate (Annegi, analytical grade), polyvinylpyrrolidone (Tianjin Guangfu Fine Chemical Research Institute, analytical grade), hexadecyltrimethylammonium bromide (Maclean's Reagent Company, analytical grade, 99.0 wt.%), polyethylene glycol 1000 (Maclean's Reagent Company, analytical grade), polyacrylamide (Sinopharm Chemical Reagent Co., Ltd., purity not less than 87 wt.%), quartz sand (Beijing Chemical Reagent Company), nitric acid (Beijing Chemical Plant, industrial grade).

[0051] Analytical testing methods: Specific surface area and pore volume were analyzed using a nitrogen physical adsorption analyzer (Tristar 3020, McMurray, USA) to assess the catalyst's texture. Specific surface area was calculated using the BET method, and pore volume was calculated using the BJH method. The morphology and structure of the catalyst were analyzed using a scanning electron microscope (SEM, GeminiSEM300, Zeiss, Germany). Magnifications were selected from 5000 to 20000x, accelerating voltages from 5 to 20 kV, working distances from 25 mm, and beam sizes from 30 nm. Hydrogenation evaluation was performed using an RPP-2000SN sulfur and nitrogen analyzer manufactured by Jiangsu Taizhou Zhonghuan Co., Ltd.

[0052] The specific preparation process of the support is as follows: Based on a total support weight of 100 wt%, the support used to prepare the catalyst consisted of 85 wt% γ-Al₂O₃ and 15 wt% HY molecular sieve. The alumina had a water absorption rate of 1.42 mL / g and a specific surface area of ​​280 m². 2 / g, sodium oxide content not exceeding 0.1wt%. HY molecular sieve has a relative crystallinity of 65%, a silica-to-alumina ratio of 10.37, a sodium oxide content not exceeding 0.1wt%, and a specific surface area of ​​434m². 2 / g, mesopore volume is 0.160cm³ 3 / g. A certain amount of guar gum powder, citric acid, and nitric acid were added to the mixture of pseudoboehmite and HY molecular sieve, while deionized water was added dropwise. After kneading evenly, the mixture was extruded into strips using a clover-shaped perforated plate with a diameter of 1.5 mm. The strips were left at room temperature for 4 hours, then dried in an oven at 120°C for 4 hours, and finally calcined at 550°C for 4 hours to obtain carrier strip 1.

[0053] The specific preparation process of carrier strip 2 is as follows: A certain amount of guar gum powder, citric acid, and nitric acid are added to the ground pseudoboehmite, while deionized water is added dropwise. After mixing evenly, the mixture is extruded into strips using a clover-shaped perforated plate with a diameter of 1.5 mm. The strips are then placed at room temperature for 4 hours, dried in an oven at 120°C for 4 hours, and finally calcined at 550°C for 4 hours to obtain carrier strip 2.

[0054] Example 1

[0055] (1) Dissolve 2.72g nickel nitrate, 3.39g ammonium molybdate, 0.013g PVP and 0.14g (NH4)2S2O3 in 20g deionized water to obtain a metal salt solution. Stir well and set aside. Weigh 10g of carrier strip 1 and place it in a crucible. Add the above mixed solution into the crucible to completely wet the carrier strip 1 to obtain a mixture.

[0056] (2) After impregnation for 3 hours at room temperature, the mixture was placed in a reactor, heated to 120°C, and allowed to stand for 10 hours. After cooling to room temperature naturally, the mixture was removed and dried in a 120°C oven for 10 hours. The hydrogenation denitrification catalyst, designated 15HY-1PVP1S, was obtained by calcination at 400°C for 5 hours in an inert gas atmosphere in a muffle furnace.

[0057] Example 2

[0058] (1) Dissolve 2.76g nickel nitrate, 3.44g ammonium molybdate, 0.017g PVP and 0.283g (NH4)2S2O3 in 20g deionized water to obtain a metal salt solution. Stir well and set aside. Weigh 10g of carrier strip 1 and place it in a crucible. Add the above mixed solution into the crucible to completely wet the carrier strip to obtain a mixture.

[0059] (2) After impregnation for 3 hours at room temperature, the mixture was placed in a reactor, heated to 120°C, and allowed to stand for 10 hours. After cooling to room temperature naturally, the mixture was removed and dried in a 120°C oven for 10 hours. The hydrogenation denitrification catalyst, denoted as 15HY-1PVP2S, was obtained by calcination at 400°C for 5 hours in an inert gas atmosphere in a muffle furnace.

[0060] Example 3

[0061] (1) Dissolve 2.76g nickel nitrate, 3.44g ammonium molybdate, 0.029g PVP and 0.142g (NH4)2S2O3 in 20g deionized water to obtain a metal salt solution. Stir well and set aside. Weigh 10g of carrier strip 1 and place it in a crucible. Add the above mixed solution into the crucible to completely wet the carrier strip to obtain a mixture.

[0062] (2) After impregnation for 3 hours at room temperature, the mixture was placed in a reactor, heated to 120°C, and allowed to stand for 10 hours. After cooling to room temperature naturally, the mixture was removed and dried in a 120°C oven for 10 hours. The hydrogenation denitrification catalyst, denoted as 15HY-2PVP1S, was obtained by calcination at 400°C for 5 hours in an inert gas atmosphere in a muffle furnace.

[0063] Comparative Example 1

[0064] (1) Dissolve 2.65g of nickel nitrate, 3.31g of ammonium molybdate and 0.013g of PVP in 20g of deionized water to obtain a metal salt solution containing dispersant. Stir well and set aside. Weigh 10g of carrier strip 2 and place it in a crucible. Add the above mixed solution into the crucible to completely wet the carrier strip 2 to obtain a mixture.

[0065] (2) After impregnation for 3 hours at room temperature, the mixture was placed in a reactor, heated to 120°C, and allowed to stand for 10 hours. After cooling to room temperature naturally, the mixture was removed and dried in a 120°C oven for 10 hours. The hydrogenation denitrification catalyst, designated 15HY-1PVP, was obtained by calcination at 400°C for 5 hours in an inert gas atmosphere in a muffle furnace.

[0066] Comparative Example 2

[0067] (1) Dissolve 2.64g of nickel nitrate, 3.27g of ammonium molybdate and 0.002g of PVP in 20g of deionized water to obtain a metal salt solution containing dispersant. Stir well and set aside. Weigh 10g of carrier strip 2 and place it in a crucible. Add the above mixed solution into the crucible to completely wet the carrier strip 2 to obtain a mixture.

[0068] (2) After impregnation for 3 hours at room temperature, the mixture was placed in a reactor, heated to 120°C, and allowed to stand for 10 hours. After cooling to room temperature naturally, it was removed and dried in a 120°C oven for 10 hours. The hydrogenation denitrification catalyst, denoted as 15HY-0.1PVP, was obtained by calcination at 400°C for 5 hours in an inert gas atmosphere in a muffle furnace.

[0069] Comparative Example 3

[0070] (1) Dissolve 3.06g of nickel nitrate, 3.81g of ammonium molybdate and 0.23g of PVP in 20g of deionized water to obtain a metal salt solution containing dispersant. Stir evenly and set aside. Weigh 10g of carrier strip 2 and place it in a crucible. Add the above mixed solution into the crucible to completely wet the carrier strip 2 to obtain a mixture.

[0071] (2) After impregnation for 3 hours at room temperature, the mixture was placed in a reactor, heated to 120°C, and allowed to stand for 10 hours. After cooling to room temperature naturally, the mixture was removed and dried in a 120°C oven for 10 hours. The hydrogenation denitrification catalyst, denoted as 15HY-10PVP, was obtained by calcination at 400°C for 5 hours in an inert gas atmosphere in a muffle furnace.

[0072] Comparative Example 4

[0073] (1) Dissolve 2.68g of nickel nitrate, 3.35g of ammonium molybdate and 1.669g of Na2S2O3 in 20g of deionized water to obtain a metal salt solution containing ammonium thiosulfate. Stir well and set aside. Weigh 10g of carrier strip 2 and place it in a crucible. Add the above mixed solution into the crucible to completely wet the carrier strip 2 to obtain a mixture.

[0074] (2) After impregnation for 3 hours at room temperature, the mixture was placed in a reactor, heated to 120°C, and allowed to stand for 10 hours. After cooling to room temperature naturally, the mixture was removed and dried in a 120°C oven for 10 hours. The hydrogenation denitrification catalyst, denoted as 15HY-1S, was obtained by calcination at 400°C for 5 hours in an inert gas atmosphere in a muffle furnace.

[0075] Comparative Example 5

[0076] (1) Dissolve 2.84g of nickel nitrate, 3.54g of ammonium molybdate and 1.765g of Na2S2O3 in 20g of deionized water to obtain a metal salt solution containing ammonium thiosulfate. Stir well and set aside. Weigh 10g of carrier strip 2 and place it in a crucible. Add the above mixed solution into the crucible to completely wet the carrier strip 2 to obtain a mixture.

[0077] (2) After impregnation for 3 hours at room temperature, the mixture was placed in a reactor, heated to 120°C, and allowed to stand for 10 hours. After cooling to room temperature naturally, the mixture was removed and dried in a 120°C oven for 10 hours. The hydrogenation denitrification catalyst, denoted as 15HY-5S, was obtained by calcination at 400°C for 5 hours in an inert gas atmosphere in a muffle furnace.

[0078] Comparative Example 6

[0079] (1) Dissolve 2.65g of nickel nitrate and 3.30g of ammonium molybdate in 20g of deionized water to obtain a metal salt solution. Stir well and set aside. Weigh 10g of carrier strip 1 and place it in a crucible. Add the above mixed solution to the crucible to completely wet the carrier strip to obtain a mixture.

[0080] (2) After impregnation for 3 hours at room temperature, the mixture was placed in a reactor, heated to 120°C, and allowed to stand for 10 hours. After cooling to room temperature naturally, the mixture was removed and dried in a 120°C oven for 10 hours. Under an inert gas atmosphere, the mixture was calcined at 400°C for 5 hours in a muffle furnace to obtain an unmodified hydrodenitrogenation catalyst, denoted as 15HY.

[0081] Comparative Example 7

[0082] Replace carrier strip 1 in Example 6 with carrier strip 2, and the rest of the preparation process is the same. The catalyst is denoted as GA.

[0083] Comparative Example 8

[0084] Dissolve 2.65g of nickel nitrate and 3.30g of ammonium molybdate in 20g of deionized water to obtain a mixed solution of metal salts. Stir well and set aside. Weigh 10g of carrier strip 2 and place it in a crucible. Add the above mixed solution to the crucible to completely wet the carrier strip to obtain a mixture.

[0085] After impregnation by standing at room temperature for 10 hours, the catalyst was dried in an oven at 120°C for 10 hours. Then, under an inert gas atmosphere, it was calcined in a muffle furnace at 400°C for 5 hours to obtain the hydrodenitrification catalyst, denoted as GA at room temperature.

[0086] The performance parameters of the catalysts obtained in the examples and comparative examples are shown in Table 1. As shown in Table 1, the hydrodenitrification catalyst prepared by the present invention with the addition of a dispersant and ammonium thiosulfate has a high specific surface area and a large pore volume.

[0087] Table 1 Performance parameters of the catalyst

[0088]

[0089] The catalysts prepared in the examples and comparative examples were evaluated for hydrodesulfurization and denitrification in a fixed-bed hydrotreating unit. The catalyst loading was 1.00 g, and it was sulfided with n-decane containing 10 vol% carbon disulfide. The hydrocracking conditions were: reaction pressure 4 MPa, hydrogen-to-oil volume ratio 300:1, and liquid hourly space velocity 8.7 h⁻¹. -1 The reaction temperatures were 300, 320, and 340 °C. Diphenylpropiophene and quinoline were used as the sulfur and nitrogen sources of the feedstock oil, which contained 2000 ppm S and 2000 ppm N. The evaluation results are listed in Tables 2 and 3.

[0090] Table 2 Evaluation results of catalyst hydrodesulfurization (HDS)

[0091]

[0092]

[0093] Table 3 Evaluation results of catalyst hydrodenitrification (HDN)

[0094]

[0095] As shown in Tables 2 and 3, the desulfurization and denitrification effects of all comparative examples in this invention are not as good as those of the examples. The hydrodenitrification catalysts prepared with dispersant and ammonium thiosulfate (Examples 1-3) have higher hydrodenitrification activity. Appropriate amounts of dispersant and ammonium thiosulfate will result in optimal denitrification and desulfurization effects. Example 1 can remove 100% of sulfur and nitrogen impurities from feedstock oil at lower temperatures and higher space velocities, showing good prospects for industrial application.

[0096] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.

Claims

1. A process for preparing a hydrodenitrogenation catalyst, characterized by, The method comprises the following steps: Step 1, mixing active component precursor, dispersant and thiosulfate to prepare impregnation solution; Step 2, mixing carrier with the impregnation solution, and then treating under heating and pressure, and then drying and calcining to obtain the hydrodenitrogenation catalyst.

2. The method of preparing a hydrodenitrogenation catalyst according to claim 1, characterized in that, The active component precursor comprises at least one of Group VIB metal-containing compound and Group VIII metal-containing compound.

3. The method of preparing a hydrodenitrogenation catalyst according to claim 2, characterized in that, The Group VIB metal comprises Mo and / or W, and the Group VIII metal comprises Co and / or Ni; the active component precursor comprises Group VIB metal-containing compound and Group VIII metal-containing compound, the Group VIB metal-containing compound comprises Mo and / or W, the Group VIII metal-containing compound comprises Co and / or Ni, and the molar ratio of the Group VIB metal-containing compound to the Group VIII metal-containing compound is 1-10:

1.

4. The method of preparing a hydrodenitrogenation catalyst according to claim 1, characterized in that, The dispersant comprises at least one of polyvinylpyrrolidone, polyethylene glycol and polyacrylamide; the amount of the dispersant added is 0.1-20wt% of the mass of the hydrodenitrogenation catalyst, based on the total mass of the hydrodenitrogenation catalyst being 100%.

5. The method of preparing a hydrodenitrogenation catalyst according to claim 1, characterized in that, The thiosulfate is ammonium thiosulfate or sodium thiosulfate; the amount of the thiosulfate added is 0.5-5wt% of the mass of the hydrodenitrogenation catalyst, based on the total mass of the hydrodenitrogenation catalyst being 100%.

6. The process for preparing a hydrodenitrogenation catalyst according to claim 1, characterized in that, The content of the active component in terms of metal is 5-25wt%, based on the total mass of the hydrodenitrogenation catalyst being 100%.

7. The process for preparing a hydrodenitrogenation catalyst according to claim 1, characterized in that, The heating and pressure treatment is to treat the mixture of the carrier and the impregnation solution at 110-200℃ and 0.2-10MPa, and the treatment time is 1-10 hours.

8. The process for preparing a hydrodenitrogenation catalyst according to claim 1, characterized in that, The carrier comprises at least one of alumina, silica, molecular sieve, activated carbon, titanium-aluminum oxide and titanium-silicon oxide; the content of the molecular sieve in the carrier is 5-30wt%.

9. The process for preparing a hydrodenitrogenation catalyst according to claim 1, characterized in that, The drying temperature is 120-150℃, the drying time is 4-10h, the calcining temperature is 200-500℃, preferably 300-400℃, the calcining time is 4-6h, and the calcining atmosphere is inert gas atmosphere.

10. The use of the hydrodenitrogenation catalyst prepared by the method of any one of claims 1-9 in the hydrodenitrogenation treatment of distillate oil.

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