Preparation method of hydrogenation molybdenum-nickel catalyst and method for hydrodenitrogenation of oil product by using hydrogenation molybdenum-nickel catalyst

Abstract

The invention provides a preparation method of a hydrogenation molybdenum-nickel catalyst and a method for hydrodenitrogenation of an oil product by using the hydrogenation molybdenum-nickel catalyst, and belongs to the technical field of clean fuel production. The preparation method comprises the following steps: dispersing metal aluminum alkoxide in an alcohol solution or a deionized water solution, and mechanically stirring at 20-120 DEG C for 2-6 hours to form a first solution; adding HNTs into the first solution, and mechanically stirring for 0.5-4 hours to form a first mixed solution; respectively dissolving an active metal Mo precursor and an active metal Ni precursor in a deionized water solution to form a second solution; adding the second solution into the first mixed solution, and mechanically stirring at 90-100 DEG C for 4-8 hours to form a second mixed solution; the second mixed solution is sequentially subjected to aging and liquid-phase heat treatment, and the hydrogenation molybdenum-nickel catalyst loaded on the HNTs-AlOOH core-shell material is obtained. According to the preparation method, the active metal dispersity of the hydrogenation molybdenum-nickel catalyst is improved, and the active sites in the catalytic process are increased.

Description

[0001] Cross - reference to related applications

[0002] This application claims the priority of the prior application 202411973093.6 filed on December 30, 2024, and the entire contents of these applications are incorporated herein by reference. Technical field

[0003] The present invention relates to the technical field of clean fuel production, and particularly relates to a preparation method of a hydro - molybdenum - nickel catalyst and a method for hydro - denitrification of oil products using the same. Background art

[0004] With the depletion of shallow light crude oil resources, large - scale development and utilization of shale oil and inferior crude oil resources have been carried out. The trend of heavy - quality and inferior - quality of crude oil is obvious, and the content of heteroatoms such as sulfur and nitrogen in crude oil increases, which puts forward higher requirements for technologies such as crude oil refining and grading. Nitrogen compounds contained in refined oil products not only form NO x , causing serious air pollution, but also inhibit the deep removal of sulfur - containing compounds in the hydro - treatment process of oil products. Therefore, one of the prerequisites for achieving deep hydro - desulfurization is to remove nitrogen compounds.

[0005] Currently, hydro - denitrification technology is an important technical means for removing nitrogen atoms from nitrogen - containing compounds in oil products. The catalytic effect of a molybdenum disulfide catalyst promoted by nickel with alumina as the carrier is widely used in the hydro - denitrification process. However, the slit - shaped disordered mesoporous structure presented by the conventional alumina carrier makes the reaction of the catalyst vulnerable to diffusion control, and at the same time, the carrier itself is prone to pore blockage, resulting in a decrease in catalyst activity and catalytic efficiency. The traditional method of improving the catalyst carrier is achieved by pore expansion. At the same time, with the inferiority of hydro - treatment raw materials and the gradual increase in the size of reaction molecules, carriers with larger pore structures are also required to meet the diffusion requirements of reactants. However, such methods usually involve the use of high - cost materials, which limits the practical application.

[0006] Therefore, it is necessary to provide a carrier with a large - pore structure at low cost to meet the catalytic requirements of hydro - denitrification. Summary of the invention

[0007] The inventors of the present invention have recognized that halloysite nanotubes (HNTs) are a low-cost and high-yield natural clay mineral and a safe and environmentally friendly material. As a natural multi-layered curly silicate material with a nano-tubular structure, halloysite nanotubes (HNTs) have better mechanical properties and thermal stability. Its unique 10-30nm hollow lumen can provide a good diffusion channel for reactants and products. However, in the field of oil hydrorefining, HNTs have the disadvantage of a relatively low specific surface area. Under the condition of a relatively high metal loading, when using HNTs as a carrier to prepare a hydrodenitrogenation catalyst, the active metal components of the catalyst show poor dispersion on its surface. Therefore, the performance of the current hydrodenitrogenation catalyst using halloysite nanotubes HNTs as a carrier fails to meet expectations.

[0008] To solve the above existing technical problems or a part of them, the purpose of the present invention is to provide a preparation method of a hydrodenickel molybdenum catalyst and a method for hydrodenitrogenating oil products using the same. The hydrodenickel molybdenum catalyst is a hydrodenickel molybdenum catalyst of a core-shell composite HNTs-AlOOH core-shell material, in which AlOOH grows in-situ on the outer surface of HNTs to form a core-shell composite HNTs-AlOOH core-shell material.

[0009] For the HNTs-AlOOH core-shell material prepared by the preparation method of the hydrodenickel molybdenum catalyst of the present invention, due to the hollow tubular structure of HNTs, it can promote the diffusion of reactants and their products in the hollow tubular structure; the AlOOH distributed on the surface of the HNTs-AlOOH core-shell material has strong acidity, which can enhance the ring opening of nitrogen-containing compounds and the cleavage of C-N bonds; the metal active components molybdenum and nickel of the hydrodenickel molybdenum catalyst are dispersed on the surface of the HNTs-AlOOH core-shell material, improving the dispersion of molybdenum and nickel of the metal active components and generating more active sites during the catalytic reaction process.

[0010] By preparing HNTs-AlOOH through the preparation method of the hydrodenickel molybdenum catalyst of the present invention, the Al species forming AlOOH is free Al 3+ , the Al 3+ adsorbs on the outer surface of HNTs and grows to form a core-shell composite HNTs-AlOOH core-shell material. Its AlOOH has good dispersion, enabling the metal active components of the hydrodenickel molybdenum catalyst to be evenly dispersed on the surface of the HNTs-AlOOH core-shell material.

[0011] According to one aspect of the present invention, a preparation method of a hydrodenickel molybdenum catalyst is provided. The preparation method includes the following steps:

[0012] Step (1): Disperse metal aluminum alkoxide in an alcohol solution or deionized aqueous solution, and mechanically stir for 2 - 6 hours at 20 - 120 °C to form a first solution;

[0013] Step (2): Add HNTs to the first solution, and mechanically stir for 0.5 - 4 hours to form a first mixed solution;

[0014] Step (3): Dissolve the active metal Mo precursor and the active metal Ni precursor separately in deionized aqueous solution in sequence to form a second solution;

[0015] Step (4): Add the second solution to the first mixed solution, and mechanically stir for 4 - 8 hours at 90 - 100 °C to form a second mixed solution;

[0016] Step (5): Subject the second mixed solution to aging and liquid-phase heat treatment in sequence to obtain a hydrodesulfurization molybdenum-nickel catalyst supported on the HNTs-AlOOH core-shell material.

[0017] In another aspect of the present invention, there is provided a method for hydrodenitrification of oil products using the hydrodesulfurization molybdenum-nickel catalyst, wherein the hydrodesulfurization molybdenum-nickel catalyst is obtained by the preparation method of the hydrodesulfurization molybdenum-nickel catalyst described above, and the method for hydrodenitrification of oil products using the hydrodesulfurization molybdenum-nickel catalyst includes the following steps:

[0018] Add the oil product and the hydrodesulfurization molybdenum-nickel catalyst to a reaction kettle, and the reaction kettle is filled with hydrogen;

[0019] Heat up and stir the reaction kettle, maintain the temperature and pressure in the reaction kettle for 2 - 6 hours to complete the hydrodenitrification reaction of the oil product, wherein the conditions in the hydrodenitrification reaction of the oil product using the hydrodesulfurization molybdenum-nickel catalyst are: the pressure is 4 - 5 MPa, the temperature is 300 - 400 °C, and the stirring rate is 500 - 700 rad / min;

[0020] In the hydrodenitrification reaction of the oil product using the hydrodesulfurization molybdenum-nickel catalyst, the denitrification rate is 50% - 60%.

[0021] According to the preparation method of the hydrodesulfurization molybdenum-nickel catalyst and the method for hydrodenitrification of oil products using the hydrodesulfurization molybdenum-nickel catalyst provided by the embodiments of the present invention, it has at least one of the following advantages or a part of an advantage:

[0022] (1) The HNTs-AlOOH core-shell material is formed from the free Al of the first solution 3+formed, rather than mechanically mixed with the AlOOH species formed by the alcoholysis or hydrolysis of all or part of the metal alkoxide of non-metallic aluminum alkoxide; adding HNTs before the alcoholysis or hydrolysis of the metal alkoxide in the first solution, the Al of the first solution 3+ is adsorbed on the surface of the HNTs in whole or in part and grows to form a uniform HNTs-AlOOH core-shell material, so that the final catalytically active metal component is highly dispersed on the surface of the HNTs-AlOOH core-shell material, improving the dispersion degree of the catalytically active metal component, and thus providing more active sites during the catalytic process.

[0023] (2) The HNTs-AlOOH core-shell material has strong acidity, which can enhance the ring opening of nitrogen-containing compounds and the cleavage of C-N bonds. The HNTs in the HNTs-AlOOH core-shell material have a hollow tubular structure, which can promote the diffusion of reactants and their products in the lumen.

[0024] (3) Using halloysite nanotubes (HNTs) with low cost and large output as the macroporous structure carrier of the hydrodenitrogenation catalyst, it has better mechanical properties and thermal stability. Its unique 10-30nm hollow lumen can provide good diffusion channels for reactants and products.

[0025] (4) The hydrodenitrogenation molybdenum-nickel catalyst prepared by the preparation method has better hydrodenitrogenation effect on oil products. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] These and / or other aspects and advantages of the present invention will become apparent and easy to understand from the following description of the preferred embodiments in conjunction with the accompanying drawings, wherein:

[0027] Figure 1 is the XRD spectrum of the hydrodenitrogenation molybdenum-nickel catalyst prepared by a preparation method of a hydrodenitrogenation molybdenum-nickel catalyst according to an embodiment of the present invention;

[0028] Figure 2 is the SEM image of the hydrodenitrogenation molybdenum-nickel catalyst prepared by a preparation method of a hydrodenitrogenation molybdenum-nickel catalyst according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] The technical solutions of the present invention will be further specifically described below through specific embodiments. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the general concept of the present invention and should not be construed as a limitation of the present invention.

[0030] In an embodiment of the present invention, a preparation method of a hydrodenitrogenation molybdenum-nickel catalyst with a core-shell composite HNTs-AlOOH core-shell material is provided. The hydrodenitrogenation molybdenum-nickel catalyst is used for hydrodenitrogenation of oil products. The preparation method includes the following steps:

[0031] Step (1): Disperse metal aluminum alkoxide in an alcohol solution or deionized aqueous solution, and mechanically stir for 2 - 6 hours at 20 - 120 °C to form a first solution;

[0032] Step (2): Add HNTs to the first solution and mechanically stir for 0.5 - 4 hours to form a first mixed solution;

[0033] Step (3): Dissolve the active metal Mo precursor and the active metal Ni precursor separately and sequentially in deionized aqueous solution to form a second solution;

[0034] Step (4): Add the second solution to the first mixed solution and mechanically stir for 4 - 8 hours at 90 - 100 °C to form a second mixed solution;

[0035] Step (5): Subject the second mixed solution to aging and liquid-phase heat treatment in sequence to obtain a hydrofining molybdenum-nickel catalyst supported on the HNTs-AlOOH core-shell material.

[0036] In one example, the HNTs-AlOOH core-shell material is formed by the free Al in the first solution 3+ adsorbing on the surface of the HNTs and growing.

[0037] It can be understood that when HNTs are added before the alcoholysis or hydrolysis of the AlOOH precursor metal aluminum alkoxide in the first solution, free Al exists in the first solution 3+ instead of AlOOH species. The free Al 3+ is all or partially adsorbed on the surface of the HNTs and highly dispersed, and finally a uniform HNTs-AlOOH core-shell material is formed. The active metal of the catalyst using this as a carrier is uniformly distributed and has a high dispersion degree, thereby leading to an improvement in catalytic efficiency.

[0038] When partial alcoholysis or hydrolysis occurs to the AlOOH precursor metal aluminum alkoxide in the first solution, both free Al 3+ and free AlOOH species exist in the first solution. When HNTs are added, part of the free Al 3+ is adsorbed on the surface of the HNTs and grows to form AlOOH species, and part of the free AlOOH species are physically mixed with the HNTs, making the AlOOH species formed by the growth of the free Al 3+ on the surface of the HNTs be dispersedly distributed, and the free AlOOH species and the HNTs are unevenly mixed and distributed. Finally, the AlOOH on the surface of the formed HNTs-AlOOH core-shell material is unevenly distributed. The active metal of the catalyst using this as a carrier is unevenly distributed and has a low dispersion degree, thereby leading to a reduction in catalytic efficiency.

[0039] When all the AlOOH precursor metal alkoxides in the first solution are alcoholyzed or hydrolyzed, there is no free Al in the first solution 3+ , but there are free AlOOH species. When HNTs are added, the free AlOOH species are physically mixed with the HNTs. The mixing of the free AlOOH species and the HNTs is uneven, and the surface AlOOH distribution of the finally formed HNTs-AlOOH core-shell material is non-uniform. The catalytically active metals supported on this carrier are unevenly distributed and have a low dispersion, which further leads to a reduction in catalytic efficiency.

[0040] In another example, the metal alkoxide includes any one of aluminum tri-sec-butoxide, aluminum butoxide, aluminum isopropoxide, or any combination thereof. The alcohol solution includes any one of ethanol, 2-butanol, isopropanol, or any combination thereof. The active metal Mo precursor is ammonium heptamolybdate tetrahydrate, and the active metal Ni precursor is any one of nickel nitrate, nickel acetate, nickel citrate, or any combination thereof.

[0041] In a further example, the aging duration of the second mixed solution is 6 - 8 days (e.g., 7 days, 7.5 days), and the aging temperature is 15 - 30 °C (e.g., 20 °C, 25 °C).

[0042] In some examples, the solvent for the liquid-phase heat treatment is liquid paraffin; the temperature of the liquid-phase heat treatment is 250 - 350 °C (e.g., 275 °C, 300 °C, 325 °C), the duration of the liquid-phase heat treatment is 3 - 5 hours (e.g., 4 hours), and the pressure of the liquid-phase heat treatment is 0.5 - 1.5 standard atmospheres (e.g., 1 standard atmosphere).

[0043] In some examples, in the HNTs-AlOOH core-shell material, the mass ratio of AlOOH:HNTs is 33wt% - 90wt%:67wt% - 10wt%.

[0044] In some examples, the content of the active metal Mo in the hydrodesulfurization molybdenum-nickel catalyst is 10wt% - 35wt% calculated as MoO 3 , and the content of the active metal Ni is 2.6wt% - 11.7wt% calculated as NiO.

[0045] In addition, an embodiment of the present invention also provides a method for hydrodenitrification of oil products using the hydrodesulfurization molybdenum-nickel catalyst. The hydrodesulfurization molybdenum-nickel catalyst is prepared by the above preparation method. The method for hydrodenitrification of oil products using the hydrodesulfurization molybdenum-nickel catalyst includes the following steps:

[0046] Add the oil product and the hydrodesulfurization molybdenum-nickel catalyst into a reaction kettle, and the reaction kettle is filled with or charged with hydrogen;

[0047] Heat up and stir the reactor, and maintain the temperature and pressure in the reactor for 2 - 6 hours to complete the hydrodenitrogenation reaction of the oil product. The conditions for the hydrodenitrogenation reaction of the oil product by the molybdenum-nickel catalyst are as follows: the pressure is 4 - 5 MPa, the temperature is 300 - 400 °C, and the stirring rate is 500 - 700 rad / min;

[0048] In the hydrodenitrogenation reaction of the oil product, the denitrification rate of the molybdenum-nickel catalyst is 50% - 60%.

[0049] In some examples, the reactor is a batch high-pressure reactor (optionally 50 - 150 ML), and the time for maintaining the temperature and pressure in the reactor is 2 - 6 hours (for example, 4 hours). The conditions for the hydrodenitrogenation reaction of the oil product by the molybdenum-nickel catalyst are as follows: the pressure is 4 - 5 MPa (for example, 4.3 MPa, 4.5 MPa, 4.83 MPa), the temperature is 300 - 400 °C (for example, 330 °C, 360 °C, 390 °C), and the stirring rate is 500 - 700 rad / min (for example, 600 rad / min).

[0050] The embodiments of the present invention will be described in detail below in the form of specific embodiments in combination with the drawings. Those skilled in the art should understand that the present invention is not limited to the specific embodiments and can be reasonably modified after understanding the concept of the present invention.

[0051] Example 1

[0052] Disperse 24.51 g of aluminum isopropoxide uniformly in 72.13 g of isopropanol solution to form the first solution. Then, before the alcoholysis of the aluminum isopropoxide, add 2.62 g of HNTs, and react at 85 °C for 3 h to obtain the first mixed solution. Weigh 1.27 g of ammonium molybdate tetrahydrate and 1.01 g of nickel nitrate hexahydrate, and respectively prepare them into the second solution with 10 mL of deionized water, and add them to the first mixed solution. React at 95 °C for 6 h to obtain the second mixed solution. Age the second mixed solution at 25 °C for 7 days, then disperse it in liquid paraffin, and perform heat treatment at 300 °C and one standard atmosphere for 4 h to obtain the catalyst Cat-1.

[0053] Use a Rigaku-D / max-2500 type X-ray diffractometer in Japan to analyze the phase structure of the catalyst Cat-1. The test conditions are room temperature, the wavelength is set to 0.15406 nm, and Cu, Kα is the radiation source. The results are as Figure 1 shown. No characteristic diffraction peaks of the MoO 3 species are detected, indicating that the dispersion of the Mo species on the HNTs-AlOOH composite material prepared by the present invention is good.

[0054] The microscopic morphology of the sample was observed using a Zeiss Gemin iSEM300 scanning electron microscope from Germany. The results are as Figure 2 shown. A 5-μm scale was selected. In the HNTs-AlOOH composite material prepared by the present invention with HNTs as the core and AlOOH as the shell, a relatively uniform structure was formed between HNTs and AlOOH.

[0055] Example 2

[0056] 24.51 g of aluminum isopropoxide was uniformly dispersed in 72.13 g of isopropanol solution to form a first solution. After reacting at 85 °C for 1.5 h, the aluminum isopropoxide underwent alcoholysis, and 2.62 g of HNTs was added to obtain a first mixed solution. 1.27 g of ammonium molybdate tetrahydrate and 1.01 g of nickel nitrate hexahydrate were weighed and separately prepared into a second solution with 10 mL of deionized water, and then added to the first mixed solution. After reacting at 95 °C for 6 hours, a second mixed solution was obtained. The second mixed solution was aged at 25 °C for 7 days, then dispersed in liquid paraffin, and heat-treated at 300 °C and one standard atmosphere for 4 h to obtain catalyst Cat-2.

[0057] Example 3

[0058] 24.51 g of aluminum isopropoxide was uniformly dispersed in 72.13 g of isopropanol solution to form a first solution. After reacting at 85 °C for 3 h, the aluminum isopropoxide underwent alcoholysis, and 2.62 g of HNTs was added to obtain a first mixed solution. 1.27 g of ammonium molybdate tetrahydrate and 1.01 g of nickel nitrate hexahydrate were weighed and separately prepared into a second solution with 10 mL of deionized water, and then added to the first mixed solution. After reacting at 95 °C for 6 hours, a second mixed solution was obtained. The second mixed solution was aged at 25 °C for 7 days, then dispersed in liquid paraffin, and heat-treated at 300 °C and one standard atmosphere for 4 h to obtain catalyst Cat-3.

[0059] Example 4

[0060] 17.51 g of aluminum isopropoxide was uniformly dispersed in 51.52 g of isopropanol solution to form a first solution. Then, before the aluminum isopropoxide underwent alcoholysis, 4.37 g of HNTs was added, and after reacting at 85 °C for 3 h, a first mixed solution was obtained. 1.27 g of ammonium molybdate tetrahydrate and 1.01 g of nickel nitrate hexahydrate were weighed and separately prepared into a second solution with 10 mL of deionized water, and then added to the first mixed solution. After reacting at 95 °C for 6 hours, a second mixed solution was obtained. The second mixed solution was aged at 25 °C for 7 days, then dispersed in liquid paraffin, and heat-treated at 300 °C and one standard atmosphere for 4 h to obtain catalyst Cat-4.

[0061] Example 5

[0062] 18.12 g of aluminum isopropoxide was uniformly dispersed in 53.31 g of deionized water to form a first solution. After reacting at 85 °C for 1.5 h, during the hydrolysis of aluminum isopropoxide, 10.55 g of HNTs was added, and stirring was continued for 1.5 h to obtain a first mixed solution. 4.05 g of ammonium molybdate tetrahydrate and 3.33 g of nickel nitrate hexahydrate were respectively dissolved in 10 mL of deionized water to prepare a second solution, which was added to the first mixed solution. After reacting at 95 °C for 6 h, a second mixed solution was obtained. The second mixed solution was aged at 25 °C for 7 days, then dispersed in liquid paraffin, and heat-treated at 300 °C and one standard atmosphere for 4 h to obtain catalyst Cat-5.

[0063] Example 6

[0064] 18.12 g of aluminum isopropoxide was uniformly dispersed in 53.31 g of deionized water to form a first solution. After reacting at 85 °C for 3 h, after the hydrolysis of aluminum isopropoxide, 10.55 g of HNTs was added to obtain a first mixed solution. 4.05 g of ammonium molybdate tetrahydrate and 3.33 g of nickel nitrate hexahydrate were respectively dissolved in 10 mL of deionized water to prepare a second solution, which was added to the first mixed solution. After reacting at 95 °C for 6 h, a second mixed solution was obtained. The second mixed solution was aged at 25 °C for 7 days, then dispersed in liquid paraffin, and heat-treated at 300 °C and one standard atmosphere for 4 h to obtain catalyst Cat-6.

[0065] Example 7

[0066] 21.78 g of aluminum isopropoxide was uniformly dispersed in 49.13 g of deionized water to form a first solution. After reacting at 50 °C for 3 h, the aluminum isopropoxide was hydrolyzed, and 12.68 g of HNTs was added to obtain a first mixed solution. 3.77 g of ammonium molybdate tetrahydrate and 3.11 g of nickel nitrate hexahydrate were respectively dissolved in 10 mL of deionized water to prepare a second solution, which was successively added to the first mixed solution. After reacting at 95 °C for 6 h, a second mixed solution was obtained. The second mixed solution was aged at 25 °C for 7 days, then dispersed in liquid paraffin, and heat-treated at 300 °C and one standard atmosphere for 4 h to obtain catalyst Cat-7.

[0067] Comparative Example 1

[0068] 0.18 g of ammonium heptamolybdate tetrahydrate and 0.15 g of nickel nitrate hexahydrate were dissolved in a certain amount of 20 wt% ammonia water solution, impregnated on 1.31 g of HNTs support in equal volume, left standing overnight at room temperature, then dried in an oven at 120 °C for 3 h, and calcined in a muffle furnace at 400 °C in an air atmosphere for 3 h to obtain catalyst Cat-11.

[0069] Comparative Example 2

[0070] Weigh 0.18 g of ammonium heptamolybdate tetrahydrate and 0.15 g of nickel nitrate hexahydrate, dissolve them in a certain amount of 20 wt% ammonia water solution, and impregnate them on 1.31 g of γ-Al 2 O 3 support. After standing overnight at room temperature, dry it in an oven at 120 °C for 3 h, and calcine it in a muffle furnace at 400 °C in an air atmosphere for 3 h to obtain catalyst Cat-12.

[0071] Comparative Example 3

[0072] Disperse 35.02 g of aluminum isopropoxide evenly in 103.04 g of isopropanol solution, and react at 85 °C to obtain mixture A. Weigh 1.23 g of ammonium molybdate and 1.01 g of nickel nitrate hexahydrate, and prepare solutions with 10 mL of deionized water respectively, then add them to mixture A. React at 95 °C for 6 h to obtain mixture B. Age mixture B at 25 °C for 7 days, then disperse it in liquid paraffin, and heat-treat it at 300 °C and one standard atmosphere for 4 h to obtain catalyst Cat-13.

[0073] Evaluate the denitrification rate of the hydrodesulfurization molybdenum-nickel catalysts produced in Examples 1-7 and Comparative Examples 1-3. Using quinoline as the model oil compound, the hydrodenitrification performance of the catalysts was evaluated in a batch high-pressure reactor (100 ml). Put 0.3 g of the sulfided catalyst into the reactor, and then add 30 g of a pre-prepared n-decane solution containing 1.0% quinoline by mass fraction. Replace the air in the reactor with nitrogen 3 times, and then replace it with hydrogen 3 times. Fill with hydrogen to 2 MPa, close the inlet valve, then start the programmed heating, and at the same time turn on the stirrer, and the stirring rate is 600 rad / min. When the temperature reaches 360 °C, the pressure in the reactor is 4.83 MPa at this time. After reacting at 360 °C for 4 h, the reaction ends. After the temperature in the reactor drops to room temperature, use a gas chromatograph (capillary column HP-5) for product analysis, and calculate the percentage content of each component by the peak area normalization method to obtain the denitrification rate of the hydrodesulfurization molybdenum-nickel catalyst, which is used to evaluate the performance of the hydrodesulfurization molybdenum-nickel catalyst.

[0074] Table 1 Evaluation results of the denitrification rate of the hydrodesulfurization molybdenum-nickel catalysts obtained in Examples 1-7 and Comparative Examples 1-3

[0075] Number of hydrodesulfurization molybdenum-nickel catalyst Denitrification rate / % Comparative Example 1 Cat-11 40 Comparative Example 2 Cat-12 48 Comparative Example 3 Cat-13 44 Example 1 Cat-1 59 Example 2 Cat-2 55 Example 3 Cat-3 53 Example 4 Cat-4 50 Example 5 Cat-5 57 Example 6 Cat-6 54 Example 7 Cat-7 51

[0076] The catalysts in Comparative Examples 1 and 2 were prepared by the equal-volume impregnation method, and the supports were HNTs and γ-Al 2 O 3(Industrial carrier). The catalyst in Comparative Example 3 does not contain HNTs, and the remaining preparation conditions are exactly the same as those of the catalyst in Example 1.

[0077] In Examples 1-3, the metal aluminum alkoxide was used in an alcoholysis manner, the loadings of the active metals Ni and Mo in the catalyst were the same, and the mass ratio of HNTs to AlOOH in the composite carrier was the same, but the addition stage of HNTs was different (in Example 1, before alcoholysis; in Example 2, during alcoholysis; in Example 3, after alcoholysis).

[0078] In the catalysts of Examples 1 and 4, the loadings of the active metals Ni and Mo were the same, the addition stage of HNTs was the same (both before alcoholysis), and the mass ratio of HNTs to AlOOH in the composite carrier was different. In Examples 5-6, the metal aluminum alkoxide was used in a hydrolysis manner, the loadings of the active metals Ni and Mo were the same, and the mass ratio of HNTs to AlOOH in the composite carrier was the same, but the addition stage of HNTs was different (in Example 5, during hydrolysis; in Example 6, after hydrolysis).

[0079] The hydrogenation reaction results show that the quinoline hydrodenitrogenation effect of the catalyst prepared by the present invention is higher than that of Comparative Examples 1-3. In addition, introducing HNTs at different stages of the alcoholysis / hydrolysis of the metal aluminum alkoxide will affect the catalytic performance of the hydrodenickel molybdenum catalyst. Compared with the hydrodenickel molybdenum catalyst prepared by introducing HNTs during or after alcoholysis / hydrolysis, the hydrodenickel molybdenum catalyst prepared by introducing HNTs before alcoholysis / hydrolysis has better catalytic performance.

[0080] In summary, the embodiments of the present invention provide a hydrodenickel molybdenum catalyst and a method for hydrodenitrogenating oil products using the hydrodenickel molybdenum catalyst, which at least have at least one of the following advantages or a part of an advantage:

[0081] (1) The HNTs-AlOOH core-shell material is formed by the free Al of the first solution 3+ rather than being formed by the mechanical mixing of the AlOOH species formed by the partial or complete alcoholysis or hydrolysis of the metal aluminum alkoxide with HNTs; adding HNTs before the alcoholysis or hydrolysis of the metal aluminum alkoxide in the first solution, the Al of the first solution 3+ adsorbs on the surface of the HNTs and grows entirely or partially to form a uniform HNTs-AlOOH core-shell material, enabling the active metal components of the final catalyst to be highly dispersed on the surface of the HNTs-AlOOH core-shell material, improving the dispersion degree of the active metal components of the catalyst, and thus providing more active sites during the catalytic process.

[0082] (2) The HNTs-AlOOH core-shell material has strong acidity, which can enhance the ring opening of nitrogen-containing compounds and the cleavage of C-N bonds. In the HNTs-AlOOH core-shell material, HNTs have a hollow tubular structure, which can promote the diffusion of reactants and their products in the lumen.

[0083] (3) Using halloysite nanotubes (HNTs) with low cost and high yield as the macroporous structure carrier of the hydrodenitrogenation catalyst, it has better mechanical properties and thermal stability. Its unique 10-30 nm hollow lumen can provide a good diffusion channel for reactants and products.

[0084] (4) The hydrodenitrogenation molybdenum-nickel catalyst prepared by the said preparation method has better hydrodenitrogenation effect on oil products.

[0085] The above are only the preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above embodiments. Those of ordinary skill in the art will understand that these embodiments can be changed without departing from the principles and spirit of the general concept of the present invention, and these changes should also be regarded as falling within the protection scope of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for preparing a hydrogenation molybdenum nickel catalyst, the preparation method comprising the following steps: Step (1): dispersing a metal aluminum alkoxide in an alcohol solution or a deionized water solution, and mechanically stirring at 20-120 degrees Celsius for 2-6 hours to form a first solution; Step (2): adding HNTs to the first solution and mechanically stirring for 0.5-4 hours to form a first mixed solution; Step (3): dissolving an active metal Mo precursor and an active metal Ni precursor in a deionized water solution in sequence to form a second solution; Step (4): adding the second solution to the first mixed solution, and mechanically stirring at 90-100 degrees Celsius for 4-8 hours to form a second mixed solution; Step (5): subjecting the second mixed solution to aging and liquid phase heat treatment in sequence to obtain a hydrogenation molybdenum nickel catalyst supported on the HNTs-AlOOH core-shell material.

2. The preparation method of the hydrogenation platinum nickel catalyst according to claim 1, characterized in that, The HNTs-AlOOH core-shell material is free Al in the first solution. 3+ Adsorbed on the surface of the HNTs and grown.

3. The preparation method of the hydrogenation platinum nickel catalyst according to claim 2, characterized in that, The metal aluminum alkoxide includes any one of aluminum tri-sec-butoxide, aluminum butoxide, and aluminum isopropoxide, or any combination thereof.

4. The preparation method of the hydrogenation platinum nickel catalyst according to claim 2, characterized in that, The alcohol solution includes any one of ethanol, 2-butanol, isopropanol or any combination thereof.

5. The preparation method of the hydrogenation platinum nickel catalyst according to claim 2, characterized in that, The active metal Mo precursor is ammonium heptamolybdate tetrahydrate, and the active metal Ni precursor is any one of nickel nitrate, nickel acetate, and nickel citrate, or any combination thereof.

6. The preparation method of the hydrogenation platinum nickel catalyst according to claim 2, characterized in that, The aging time of the second mixed solution is 6-8 days, and the aging temperature is 15-30 degrees Celsius.

7. The preparation method of the hydrogenation platinum nickel catalyst according to claim 2, characterized in that, The solvent of the liquid phase heat treatment is liquid paraffin; The temperature of the liquid phase heat treatment is 250-350 degrees Celsius, the duration of the liquid phase heat treatment is 3-5 hours, and the pressure of the liquid phase heat treatment is 0.5-1.5 standard atmospheres.

8. The preparation method of the hydrogenation platinum nickel catalyst according to claim 2, characterized in that, In the HNTs-AlOOH core-shell material, the mass ratio of AlOOH to HNTs is 33wt%-90wt%: 67wt%-10wt%.

9. The method for preparing a hydrogenation platinum nickel catalyst according to any one of claims 1 to 8, characterized in that: The content of active metal Mo in the hydrogenation molybdenum nickel catalyst is 10wt%-35wt% in terms of MoO3, and the content of active metal Ni is 2.6wt%-11.7wt% in terms of NiO.

10. A method for hydrodenitrification of oil products using a hydrogenation molybdenum nickel catalyst, wherein the hydrogenation molybdenum nickel catalyst is prepared by the preparation method according to any one of claims 1 to 9, and the method for hydrodenitrification of oil products using a hydrogenation molybdenum nickel catalyst comprises the following steps: Adding the oil product and the hydrogenation molybdenum-nickel catalyst into a reaction kettle, wherein the reaction kettle is filled with hydrogen; The reactor is heated and stirred, and the temperature and pressure in the reactor are maintained for 2-6 hours to complete the hydrodenitrogenation reaction of the oil product, wherein the conditions for the hydrodenitrogenation reaction of the oil product with the hydrogenation molybdenum nickel catalyst are: pressure of 4-5MPa, temperature of 300-400 degrees Celsius, and stirring rate of 500-700rad / min; The hydrogenation molybdenum nickel catalyst has a denitrification rate of 50%-60% in the hydrodenitrogenation reaction of the oil product.

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