A method for hydrotreating inferior oil

Abstract

This invention provides a method for hydrotreating inferior oil. The method employs a fixed-bed hydrotreating process. In the presence of hydrogen, the inferior oil is sequentially contacted with at least one hydrodesulfurization catalyst and at least one hydrodenitrification catalyst to undergo a hydrotreating reaction, yielding hydrotreated oil. The hydrodesulfurization catalyst comprises a support and an active component, preferably including an additive. The support comprises a silicon-modified nickel-aluminum alloy, and the active component is an organomolybdenum, preferably alkyl dithiophosphate molybdenum and / or alkyl dithiocarbamate molybdenum, with an additive being organozinc. The hydrodenitrification catalyst also comprises a support and an active component. The support comprises a silicon-modified nickel-aluminum alloy, and the active component includes an organomolybdenum, preferably alkyl dithiophosphate molybdenum and / or alkyl dithiocarbamate molybdenum. Preferably, the hydrodenitrification catalyst includes an additive organogallium. This hydrotreating method exhibits strong desulfurization and denitrification effects for inferior secondary processed oils.

Description

Technical Field

[0001] This invention belongs to the field of petrochemicals and relates to a method for hydrogenating inferior secondary processed oil. Background Technology

[0002] Delayed coking, fluidized bed hydrotreating, and catalytic cracking processes generate large quantities of low-quality secondary processed oils with high aromatic, sulfur, and nitrogen content. These oils require further hydrotreating to meet usage standards. Processing these low-quality secondary processed feedstocks necessitates specific catalyst grading techniques. The basic principle of grading is to reduce catalyst particle size, average pore size, and catalyst activity along the direction of the reaction liquid stream.

[0003] CN113862027A discloses a method for grading heavy oil hydrotreating catalysts. In this method, the total amount of hydroxyl groups on the support in each catalyst gradually increases, and the ratio of acidic hydroxyl groups to basic hydroxyl groups gradually increases. This grading method results in the heavy oil hydrotreating catalyst exhibiting excellent reactivity and stability when used in the aforementioned heavy oil hydrotreating catalyst gradation, effectively extending the operating cycle of the heavy oil hydrotreating unit. However, the excessively acidic catalyst in the later stages of gradation leads to severe coking and carbon deposition when processing low-quality oils, especially those with high aromatic content.

[0004] CN111196935A discloses a method for grading hydrotreating catalysts, wherein the MoS2 in the hydrodemetallization catalyst after sulfidation is mainly dispersed in single and double layers, and the MoS2 in the hydrodesulfurization catalyst after sulfidation is mainly multilayered. The catalyst gradations obtained by this method have high demetallization, decarbonization, desulfurization, and denitrification activities and stability, and a long service life. However, during gradation, the utilization rate of molybdenum disulfide metal in the multilayers is low, which poses certain difficulties for deep hydrodenitrification and aromatic saturation of inferior oil products. Summary of the Invention

[0005] This invention provides a hydrotreating method for inferior oil, which has a strong desulfurization and denitrification effect on inferior secondary processed oil.

[0006] This invention provides a method for hydrotreating inferior oil, which employs a fixed-bed hydrotreating process. In the presence of hydrogen, the inferior oil is sequentially contacted with at least one hydrodesulfurization catalyst and at least one hydrodenitrogenation catalyst to carry out a hydrotreating reaction, thereby obtaining hydrotreated oil.

[0007] The hydrodesulfurization catalyst includes a support and an active component, preferably including an additive. The support includes a silicon-modified nickel-aluminum alloy, the active component is an organomolybdenum, preferably alkyl dithiophosphate molybdenum and / or alkyl dithiocarbamate molybdenum, and the additive is an organozinc, preferably alkyl dithiophosphate zinc and / or alkyl dithiocarbamate zinc.

[0008] The hydrodenitrification catalyst includes a support and an active component. The support includes a silicon-modified nickel-aluminum alloy, and the active component includes an organomolybdenum, preferably an alkyl dithiophosphate molybdenum and / or an alkyl dithiocarbamate molybdenum. Preferably, the hydrodenitrification catalyst includes an auxiliary organogallium.

[0009] Furthermore, in the hydrodesulfurization catalyst and the hydrodenitrogenation catalyst, the alkyl molybdenum dithiophosphate is independently selected from one or more of diisopropyl molybdenum dithiophosphate, dibutyl molybdenum dithiophosphate oxysulfide, and diisooctyl molybdenum dithiophosphate. The alkyl molybdenum dithiocarbamate is independently selected from one or more of dibutyl molybdenum dithiocarbamate and diisopropyl molybdenum dithiocarbamate.

[0010] Furthermore, in the hydrodesulfurization catalyst, the alkyl dithiophosphate zinc is selected from one or more of dibutyl dithiophosphate zinc, isodecyl dithiophosphate zinc, diisooctyl dithiophosphate zinc, and di(tetradecyl)alkyl dithiophosphate zinc. The alkyl dithiocarbamate zinc is selected from one or more of diethyl dithiocarbamate zinc, ethylphenyl dithiocarbamate zinc, and dibutyl dithiocarbamate zinc.

[0011] Furthermore, when using organic zinc compounds in the hydrodesulfurization catalyst, the organic zinc compounds and sulfur-containing organic molybdenum compounds have similar physicochemical properties and similar distribution patterns and positions on the surface of the nickel-aluminum alloy support, thus avoiding phase separation between zinc and molybdenum, making the hydrogenation effect, especially the hydrodesulfurization effect, more obvious.

[0012] Furthermore, in the hydrodenitrogenation catalyst, the organogallium is one or more of triethylgallium, triisopropylgallium, tri-tert-butylgallium, gallium acetylacetonate, gallium ethoxylate, and gallium isopropoxide. Using organogallium compounds as promoters, since gallium and aluminum belong to the same group, they can also combine with nickel and interact with the supported organomolybdenum species, which is beneficial for improving hydrodenitrogenation activity. Simultaneously, organogallium can form a strong Ga-N triple bond with nitrogen, exhibiting a very strong interaction with nitrides in oil products, which is highly beneficial for improving hydrodenitrogenation activity.

[0013] Further, in the hydrodesulfurization catalyst or hydrodenitrogenation catalyst, the silicon-modified nickel-aluminum alloy is an organosilicon-modified nickel-aluminum alloy, specifically an alkoxysilane. More preferably, the alkoxysilane is selected from at least one of methyltrimethoxysilane, triethoxysilane, methyltriethoxysilane, propyltrimethoxysilane, butyltriethoxysilane, and octyltriethoxysilane. Using this preferred embodiment, the silicon-modified nickel-aluminum alloy as the catalytic substrate in the catalyst can provide a large amount of activated hydrogen, creating conditions for hydrogen transfer. Combined with organomolybdenum, particularly dialkyldithiophosphate molybdenum and / or alkyldithiocarbamate molybdenum, as the active component, the sulfur-containing molybdenum species combine with nickel to form more Ni-Mo-S active sites, providing hydrogenation centers and further improving the utilization rate of molybdenum and the hydrogenation activity of the catalyst.

[0014] Furthermore, in this invention, the range of choices for the nickel-aluminum alloy is quite wide. The nickel-aluminum alloy has its conventional meaning in the art, and its source is not particularly limited; it can be commercially purchased or self-made, and self-making can be carried out using any feasible method.

[0015] Furthermore, in this invention, the range of nickel and aluminum content in the nickel-aluminum alloy is relatively wide. Preferably, based on the total amount of the nickel-aluminum alloy, the aluminum content (based on elemental concentration) is 50 wt% to 95 wt%, and the nickel content (based on elemental concentration) is 5 wt% to 50 wt%. More preferably, based on the total amount of the nickel-aluminum alloy, the aluminum content (based on elemental concentration) is 70 wt% to 90 wt%, and the nickel content (based on elemental concentration) is 10 wt% to 30 wt%. This preferred embodiment not only allows nickel to effectively combine with sulfur-containing organomolybdenum compounds to improve the hydrogenation performance of the catalyst, but also prevents the nickel content in the nickel-aluminum alloy from becoming too high.

[0016] Furthermore, based on the total dry weight of the hydrodenitrogenation catalyst or the hydrodesulfurization catalyst, the content of Al, calculated as aluminum oxide, is 62% to 84%, preferably 68% to 80%; the content of Ni, calculated as nickel oxide, is 8% to 18%, preferably 9% to 15%; the content of molybdenum, calculated as molybdenum trioxide, is 6% to 18%, preferably 8% to 17%; the content of silicon, calculated as silicon dioxide, is 0.2% to 3%, preferably 0.5% to 2%; and the content of additives, calculated as metal oxides, is 1.5% to 7%, preferably 2% to 5.5%.

[0017] Furthermore, in this invention, the dry basis measurement method of the hydrodenitrification catalyst or hydrodesulfurization catalyst is as follows: In an air atmosphere, the catalyst is heated from 120°C to 420°C at a rate of 3.0°C per minute, and then calcined for 4.0 hours at 550°C for 2.0 hours at a rate of 3.0°C per minute. The resulting material is analyzed in a dry environment.

[0018] Furthermore, the content of each component in the dry basis can be determined using atomic emission spectrometry (ICP-AES), specifically using an OPTIMA 7000DV atomic emission spectrometer manufactured by PE Corporation. In a typical solution preparation process, 0.1 g of sample is dissolved in a mixed solution with a volume ratio of 3HCl:1HNO3:0.5HF. The mixed solution is then diluted with deionized water to a certain volume, ensuring that the content of the analyte element in the solution is between 1 and 10 ppm, thereby increasing the accuracy of the measurement data.

[0019] Furthermore, the analysis of organometallic compounds in the catalyst can be performed using XPS. The XPS testing conditions include: light source: Mg Kα, energy step: 0.05 eV, scan range: 200-250 eV (molybdenum), 280-300 eV (carbon). When analyzing the valence state of molybdenum, molybdenum species with a 3d5 / 2 orbital binding energy of 227-228 eV are considered to have a valence of 0; those with a valence between 228-229 eV are considered to have a valence of +2; those with a valence between 229-231 eV are considered to have a valence of +4; and those with a valence greater than 231 eV are considered to have a valence of +5 or +6.

[0020] Among them, the 3d5 / 2 orbital of the organometallic molybdenum is between 227 and 229 eV, belonging to molybdenum species with valences between 0 and +2. Other organometallic compounds, such as Ga, were tested using methods similar to those for molybdenum. Analysis revealed that the valence states of these metal additives belonged to organic species with valences between 0 and +1, proving the existence of organomolybdenum compounds.

[0021] Furthermore, the present invention allows for a wide range of pore volumes for the hydrodesulfurization catalyst or the hydrodenitrogenation catalyst. Preferably, the pore volumes of each hydrodenitrogenation catalyst are independently 0.1–1 cm. 3 / g, preferably 0.15~0.6cm 3 / g.

[0022] Furthermore, according to a preferred embodiment of the present invention, the average pore size of the hydrodesulfurization catalyst or the hydrodenitrogenation catalyst is independently 4 to 15 nm, preferably 6 to 12 nm.

[0023] Furthermore, according to a preferred embodiment of the present invention, in the hydrodesulfurization catalyst or hydrodenitrogenation catalyst, the pore volume of 0-3 nm pores accounts for 1%-10% of the total pore volume, preferably 2%-5%. Using the catalyst under the preferred embodiment is more conducive to the mass transfer and diffusion of reactant molecules.

[0024] Furthermore, according to some embodiments of the present invention, the pore volume of the catalyst in the 0-3 nm range and the total pore volume are determined by nitrogen isothermal adsorption-desorption method.

[0025] Furthermore, the preparation method of the hydrodesulfurization catalyst includes:

[0026] An impregnation solution containing organic molybdenum and optional organic zinc is prepared and then impregnated onto a silicon-modified nickel-aluminum alloy support. After drying, a hydrodesulfurization catalyst is obtained.

[0027] Furthermore, the silicon-modified nickel-aluminum alloy carrier is an organosilicon-modified nickel-aluminum alloy carrier, and the method for modifying the organosilicon-modified nickel-aluminum alloy carrier includes: contacting the nickel-aluminum alloy with an alkoxysilane gas to perform silicon modification. Preferably, the method further includes a vacuum treatment of the nickel-aluminum alloy before the organosilicon modification and a displacement treatment after the silicon modification. This approach is more conducive to the deposition of alkoxysilanes on the pores of the nickel-aluminum alloy carrier.

[0028] Furthermore, a preferred preparation method for the hydrodesulfurization catalyst of the present invention includes:

[0029] (a) Vacuum treatment of the nickel-aluminum alloy carrier;

[0030] (b) Introduce alkoxysilane gas into the carrier treated in step (a) for modification treatment;

[0031] (c) Replace the alkoxysilane gas described in step (b) with nitrogen and / or an inert gas to obtain a modified nickel-aluminum alloy carrier;

[0032] (d) Prepare an impregnation solution containing organic molybdenum and organic zinc, then impregnate it onto the modified nickel-aluminum alloy support obtained in step (c), and dry it to obtain a hydrodesulfurization catalyst.

[0033] Further, in step (a), the pore volume of the nickel-aluminum alloy carrier is 0.4–1.0 cm³. 3 / g, preferably with a pore volume of 0.5–0.9 cm³. 3 / g, with an average pore size of 4–12 nm, preferably 6–10 nm, wherein the volume proportion of pores smaller than 3.0 nm is no more than 20%, preferably 5–10%.

[0034] Furthermore, the present invention provides a wide range of particle size selection for the nickel-aluminum alloy carrier, which can be adapted to the actual application environment. Preferably, the average particle size of the nickel-aluminum alloy carrier is 1-8 mm, and more preferably 2-5 mm.

[0035] Further, in step (a), the conditions for the vacuuming process are: a vacuum degree of 0.05-1.0 torr, preferably 0.1-0.5 torr, a processing time of 2-10 hours, preferably 4-8 hours, and a temperature of 50-140℃, preferably 60-120℃.

[0036] Further, in step (b), before introducing the alkoxysilane gas, a heating operation is performed according to the boiling point of the alkoxysilane used, so that the alkoxysilane is in a gaseous state. The alkoxysilane gas is preferably one or more of methyltrimethoxysilane, triethoxysilane, methyltriethoxysilane, propyltrimethoxysilane, isobutyltriethoxysilane, and n-octyltriethoxysilane.

[0037] Further, in step (b), at least one of nitrogen and / or an inert gas is introduced as a carrier gas simultaneously with the alkoxysilane gas. The partial pressure of the alkoxysilane gas is 0.02-1.0 MPa, preferably 0.05-0.5 MPa; the modification treatment temperature is 150-400℃, preferably 180-350℃; the treatment time is 1.0-10.0 hours, preferably 2.0-8.0 hours; and the flow rate of the alkoxysilane gas is 1.0-20.0 mL / min·g. -1 Nickel-aluminum alloy carrier, preferably 3.0-15 mL / min·g -1 Nickel-aluminum alloy carrier.

[0038] Furthermore, in step (b), the inert gas is preferably one or a mixture of several of argon and neon.

[0039] Further, in step (c), the conditions for the displacement include: the inert gas introduction rate is 0.5-5 mL / min·g. -1 Nickel-aluminum alloy carrier, preferably 1-4 mL / min·g -1 The nickel-aluminum alloy carrier has a replacement time of 0.5-8.0 hours, preferably 1.0-4.0 hours, and a temperature of 100-400℃, preferably 150-350℃.

[0040] Further, in step (d), the organomolybdenum source and the organozinc source are mixed with a solvent to prepare an impregnation solution. The organomolybdenum source is one or more of alkyl molybdenum dithiophosphate and / or alkyl molybdenum dithiocarbamate. The organozinc source is one or more of alkyl zinc dithiophosphate and / or alkyl molybdenum dithiocarbamate. The solvent is one or a mixture of n-hexane, n-heptane, n-octane, or n-nonane. In the impregnation solution, the concentrations of the organomolybdenum and organozinc sources are each independently 0.1–3 mol / L.

[0041] Furthermore, in step (d), the impregnation can be performed using at least one of the conventional methods in the art, such as equal-volume impregnation or supersaturated impregnation.

[0042] Further, in step (d), the drying is vacuum drying, with a vacuum degree of 0.5-5.0 torr, preferably 1.0-3.0 torr, a drying temperature of 60-150℃, preferably 70-120℃, and a drying time of 2.0-12.0h, preferably 4.0-8.0h.

[0043] Furthermore, the method for preparing the hydrodenitrification catalyst includes the following steps:

[0044] (1) Preparation of silicon-modified nickel-aluminum alloy carrier;

[0045] (2) Prepare an impregnation solution containing an organomolybdenum compound and an optional organogallium compound, impregnate it onto the silicon-modified nickel-aluminum alloy support obtained in step (1), and dry it to obtain a hydrodenitrification catalyst.

[0046] In step (2), when preparing the impregnation solution, the organic molybdenum compound used is preferably alkyl dithiophosphate molybdenum and / or alkyl dithiocarbamate molybdenum.

[0047] Further, in step (1), the silicon-modified nickel-aluminum alloy carrier is an organosilicon-modified nickel-aluminum alloy carrier. The method for modifying the organosilicon-modified nickel-aluminum alloy carrier includes: contacting the nickel-aluminum alloy with a gaseous silicon-containing compound to perform silicon modification. Preferably, the method further includes vacuuming the nickel-aluminum alloy before the organosilicon modification and displacement treatment after the silicon modification. This approach is more conducive to the deposition of alkoxysilanes on the pores of the nickel-aluminum alloy carrier.

[0048] Furthermore, a preferred method for obtaining the organosilicon-modified nickel-aluminum alloy carrier includes: subjecting the nickel-aluminum alloy carrier to vacuum treatment, then introducing a gaseous silicon-containing compound for organosilicon modification treatment, and then introducing nitrogen and / or an inert gas for replacement to obtain the modified nickel-aluminum alloy carrier.

[0049] Furthermore, in step (1), the pore volume of the nickel-aluminum alloy carrier is 0.4–1.0 cm³. 3 / g, preferably with a pore volume of 0.5–0.9 cm³. 3 / g, with an average pore size of 4-12nm, preferably 6-10nm, wherein the volume ratio of pores smaller than 3.0nm is not higher than 20%, preferably 5-10%.

[0050] Furthermore, the present invention provides a wide range of particle size selection for the nickel-aluminum alloy carrier, which can be adapted to the actual application environment. Preferably, the average particle size of the nickel-aluminum alloy carrier is 1-8 mm, and more preferably 2-5 mm.

[0051] Further, in step (1), the temperature of the vacuuming process is 50-200℃, preferably 80-150℃; the vacuum degree is 0.05-1.0 torr, preferably 0.1-0.5 torr; and the processing time is 2-10 hours, preferably 4-8 hours.

[0052] Further, in step (1), before introducing the gaseous silicon-containing compound, a heating operation is performed according to the boiling point of the gaseous silicon-containing compound used. The specific temperature can be adjusted according to the corresponding boiling point. The gaseous silicon-containing compound is a gaseous alkoxysilane, preferably one or more of methyltrimethoxysilane, triethoxysilane, methyltriethoxysilane, propyltrimethoxysilane, isobutyltriethoxysilane, and n-octyltriethoxysilane.

[0053] Further, in step (1), at least one of nitrogen and / or an inert gas is introduced as a carrier gas simultaneously with the introduction of the silicon-containing compound into the gas phase. The partial pressure of the silicon-containing compound in the gas phase is 0.02-1.0 MPa, preferably 0.05-0.5 MPa; the modification treatment temperature is 200-450℃, preferably 250-400℃; the treatment time is 1.0-10.0 hours, preferably 2.0-8.0 hours; and the flow rate of the silicon-containing compound introduced into the gas phase is 1.0-20.0 mL / min·g. -1 Nickel-aluminum alloy carrier, preferably 3.0-15.0 mL / min·g -1 Nickel-aluminum alloy carrier.

[0054] Furthermore, in step (1), the inert gas is preferably one or a mixture of argon and neon.

[0055] Further, in step (1), the conditions for the replacement include: the introduction rate of nitrogen and / or inert gas is 0.5-5 mL / min·g. -1 Nickel-aluminum alloy carrier, preferably 1-4 mL / min·g -1 The nickel-aluminum alloy carrier has a replacement time of 0.5-8.0 hours, preferably 1.0-4.0 hours, and a temperature of 100-400℃, preferably 150-350℃.

[0056] Further, in step (2), the organic molybdenum source and the organic gallium source are mixed with a solvent to prepare an impregnation solution. The solvent is one or a mixture of several of the following: n-hexane, n-heptane, n-octane, n-nonane, cyclohexane, ethanol, methanol, and isopropanol. In the impregnation solution, the concentrations of the organic molybdenum source and the organic gallium source are each independently 0.1–3 mol / L.

[0057] Further, the alkyl molybdenum dithiophosphate is selected from one or more of diisopropyl molybdenum dithiophosphate, dibutyl molybdenum dithiophosphate sulfide, and diisooctyl molybdenum dithiophosphate. The alkyl molybdenum dithiocarbamate is selected from one or more of dibutyl molybdenum dithiocarbamate and diisopropyl molybdenum dithiocarbamate. The organic gallium source is one or more of triethylgallium, triisopropylgallium, tritert-butylgallium, gallium acetylacetonate, gallium ethoxylate, and gallium isopropoxide.

[0058] Furthermore, in step (2), the impregnation can be performed using at least one of the conventional methods in the art, such as equal volume impregnation or supersaturated impregnation.

[0059] Further, in step (2), the drying is vacuum drying, with a vacuum degree of 0.5-5.0 torr, preferably 1.0-3.0 torr, a drying temperature of 60-150℃, preferably 70-120℃, and a drying time of 2.0-12.0h, preferably 4.0-8.0h.

[0060] Furthermore, the hydrodesulfurization catalyst and the hydrodenitrification catalyst need to be activated before use. The activation conditions include: hydrogen pressure of 0.1-1.0 MPa, preferably 0.2-0.8 MPa; activation temperature of 80-250℃, preferably 120-200℃; activation time of 0.5-5.0 h, preferably 1.0-3.0 h; and hydrogen flow rate of 3.0-15.0 mL / h·g. -1 The preferred hydrodenitrogenation catalyst is 5.0-10.0 mL / h·g. -1 Hydrogenation denitrification catalyst.

[0061] Furthermore, the operating conditions of the fixed-bed hydrogenation process are as follows: the reaction hydrogen pressure is 2.0-20.0 MPa, preferably 6.0-16.0 MPa; the hydrogen-to-oil volume ratio is 200:1-1500:1, preferably 500:1-1200:1; and the volume hourly space velocity is 0.2-3.0 h⁻¹. -1 Preferably 0.5-2.0h -1 The reaction temperature is 280-380℃ for the desulfurization catalyst bed, preferably 300-360℃, and 300-400℃ for the denitrification catalyst bed, preferably 320-380℃.

[0062] Furthermore, the loading volume ratio of the hydrodesulfurization catalyst to the hydrodenitrogenation catalyst has a wide range, for example, it can be 10-90:10-90. Furthermore, the inferior oil is a secondary processed oil with the following properties: nitrogen content of 300-3000 μg / g, sulfur content of 2000-30000 μg / g, and aromatic content of 15wt%-80wt%, preferably 30wt%-70wt%.

[0063] Compared with the prior art, the present invention has the following advantages:

[0064] 1. The hydrodenitrification catalyst and hydrodesulfurization catalyst used in this invention enable the alkoxysilane-vapor phase deposition method to ensure that alkoxysilanes preferentially block the pores of the catalyst, thereby optimizing the pore structure of the nickel-aluminum alloy catalyst and preventing the subsequent deposition of molybdenum metal in the pores. At the same time, the organosilicon on the surface of the nickel-aluminum alloy can effectively divide the nickel surface and prevent the accumulation of molybdenum species on the nickel surface.

[0065] 2. The hydrodesulfurization catalyst used in this invention employs alkyl molybdenum dithiophosphate (and / or alkyl molybdenum dithiocarbamate) as the molybdenum source. Due to the steric hindrance effect of alkyl substitution on the nickel-aluminum alloy surface, the molybdenum sulfide species are highly dispersed. After mild hydrogen treatment, the resulting Ni-Mo-S active phase has more active centers than the molybdenum species obtained from the oxidized state after sulfidation and unsupported MoS2 particles, thus improving molybdenum utilization and the catalyst's hydrogenation activity. Simultaneously, alkyl zinc dithiophosphate and / or alkyl zinc dithiocarbamate are used as additives. Because alkyl zinc dithiophosphate and / or alkyl zinc dithiocarbamate have similar physicochemical properties to specific active components, their distribution patterns on the modified nickel-aluminum alloy support surface are similar, and their distribution positions are close, avoiding phase separation between zinc and molybdenum. This makes the additive effect more pronounced and beneficial for deep desulfurization.

[0066] 3. The hydrodenitrification catalyst used in this invention uses a modified nickel-aluminum alloy as the support material for the catalytic substrate, which can provide a large amount of activated hydrogen and provide conditions for hydrogen transfer. It is combined with alkyl dithiophosphate molybdenum (and / or alkyl dithiocarbamate molybdenum) as an active component. The sulfur-containing molybdenum species combine with nickel to form Ni-Mo-S active sites, providing hydrogenation centers. At the same time, organogallium is used as an auxiliary agent to further improve the hydrodenitrification effect.

[0067] 4. This invention uses specific hydrodesulfurization and hydronitrogenation catalysts in combination, which still have a strong desulfurization and denitrogenation effect on inferior secondary processed oils. Detailed Implementation

[0068] The present invention will be further described below with reference to the embodiments, but the following embodiments do not constitute a limitation of the present invention. Unless otherwise specified, the percentage content of the materials mentioned herein is a mass percentage content.

[0069] This invention selects two types of nickel-aluminum alloys as matrix supports for hydrodesulfurization catalyst and hydrodenitrification catalyst, respectively. The matrix support for hydrodesulfurization catalyst is designated as nickel-aluminum alloy-I, and the matrix support for hydrodenitrification catalyst is designated as nickel-aluminum alloy-II.

[0070] The properties of nickel-aluminum alloy-I are: average grain size 4.1 mm, pore volume 0.72 cm³. 3 / g, the average pore size of the support is 8.3nm, the pore volume of pores smaller than 3nm is 7.6%, the mass fraction of Al is 83.6%, and the mass fraction of Ni is 16.4%.

[0071] The properties of nickel-aluminum alloy II are: average grain size 3.2 mm, pore volume 0.68 cm³. 3 / g, the average pore size of the support is 7.5nm. The volume of pores smaller than 3nm is 8.1%. The mass fraction of Al is 80.1%, and the mass fraction of Ni is 19.9%.

[0072] Example 1

[0073] Place 100.0g of nickel-aluminum alloy-I particles into a vacuum drying oven, control the vacuum degree at 0.2 torr, the temperature at 80℃, and the processing time at 4.0 hours.

[0074] The temperature of the vacuum drying oven was raised to 220℃, and nitrogen and methyltrimethoxysilane gas were introduced into it. The partial pressure of methyltrimethoxysilane gas was 0.1 MPa, the gas flow rate was 400 mL / min, and the gas introduction time was 3.0 hours.

[0075] The temperature of the drying oven was adjusted to 160℃, and the drying oven was purged with nitrogen at a rate of 200 mL / min for 1 hour. The resulting modified nickel-aluminum alloy carrier was denoted as L-1.

[0076] Prepare impregnation solution Q-1 by taking 20.0g of molybdenum diisopropyl dithiophosphate, 6.0g of zinc dibutyl dithiophosphate, and 70.0g of n-heptane.

[0077] L-1 was impregnated with Q-1, and then vacuum dried at 70°C with a vacuum degree of 1.0 torr for 4.0 hours. The resulting catalyst is designated Cat-1.

[0078] Example 2

[0079] Place 100.0g of nickel-aluminum alloy-I particles into a vacuum drying oven, control the vacuum degree at 0.4 torr, the temperature at 100℃, and the processing time at 5.0 hours.

[0080] The temperature of the vacuum drying oven was raised to 240℃, and nitrogen and triethoxysilane were introduced into it. The partial pressure of the triethoxysilane was 0.1 MPa, the gas flow rate was 450 mL / min, and the gas introduction time was 4.0 hours.

[0081] The temperature of the drying oven was adjusted to 170℃, and the drying oven was purged with nitrogen at a rate of 200 mL / min for 1.5 hours. The resulting modified nickel-aluminum alloy carrier was denoted as L-2.

[0082] Prepare impregnation solution Q-2 by taking 25.0g of dibutyl dithiophosphate molybdenum sulfide, 8.0g of diisooctyl dithiophosphate zinc, and 70.0g of n-octane.

[0083] L-2 was impregnated with Q-2, and then vacuum dried at 90°C with the vacuum level controlled at 1.0 torr for 4.0 hours. The resulting catalyst is designated Cat-2.

[0084] Example 3

[0085] Place 100.0g of nickel-aluminum alloy-I particles into a vacuum drying oven, control the vacuum degree at 0.5 torr, the temperature at 120℃, and the processing time at 5.0 hours.

[0086] The temperature of the vacuum drying oven was raised to 270℃, and nitrogen and isobutyltriethoxysilane were introduced into it. The partial pressure of isobutyltriethoxysilane was 0.1 MPa, the gas flow rate was 500 mL / min, and the gas introduction time was 5.0 hours.

[0087] The temperature of the drying oven was adjusted to 200℃, and the drying oven was purged with nitrogen at a rate of 200 mL / min for 2.0 hours. The resulting modified nickel-aluminum alloy carrier was designated L-3.

[0088] Prepare impregnation solution Q-3 by taking 20.0g of molybdenum diisopropyl dithiocarbamate, 4.0g of zinc diethyl dithiocarbamate, and 70.0g of n-nonane.

[0089] L-3 was impregnated with Q-3, and then vacuum dried at 120°C with the vacuum level controlled at 1.0 torr for 4.0 hours. The resulting catalyst is designated Cat-3.

[0090] Example 4

[0091] 100.0g of nickel-aluminum alloy-II carrier particles were placed in a vacuum drying oven, and the vacuum degree was controlled at 0.4 torr, the temperature at 100℃, and the processing time was 5.0 hours.

[0092] The temperature of the vacuum drying oven was raised to 240℃, and nitrogen and triethoxysilane gas were introduced into it. The partial pressure of the triethoxysilane gas was 0.1 MPa, the gas flow rate was 450 mL / min, and the gas introduction time was 4.0 hours.

[0093] The temperature of the drying oven was adjusted to 170℃, and the drying oven was purged with nitrogen at a rate of 200 mL / min for 1.5 hours. The resulting modified nickel-aluminum alloy carrier was designated L-4.

[0094] Prepare impregnation solution Q-4 by taking 25.0g of molybdenum sulfide dibutyl dithiophosphate, 8.0g of gallium acetylacetonate, 40.0g of n-heptane and 30.0g of ethanol.

[0095] L-4 was impregnated with Q-4, and then vacuum dried at 90°C with the vacuum level controlled at 1.0 torr for 4.0 hours. The resulting catalyst is designated Cat-4.

[0096] Example 5

[0097] Place 100.0g of nickel-aluminum alloy-II particles into a vacuum drying oven, control the vacuum degree at 0.5 torr, the temperature at 120℃, and the processing time at 5.0 hours.

[0098] The temperature of the vacuum drying oven was raised to 270℃, and nitrogen and isobutyltriethoxysilane gas were introduced into it. The partial pressure of the isobutyltriethoxysilane gas was 0.1 MPa, the gas flow rate was 500 mL / min, and the gas introduction time was 5.0 hours.

[0099] The temperature of the drying oven was adjusted to 200℃, and the drying oven was purged with nitrogen at a rate of 200 mL / min for 2.0 hours. The resulting modified nickel-aluminum alloy carrier was designated L-5.

[0100] Prepare impregnation solution Q-5 by taking 20.0g of molybdenum diisopropyl dithiocarbamate, 6.0g of gallium ethoxylate, 40.0g of n-nonane and 30.0g of ethanol.

[0101] L-5 was impregnated with Q-5, and then vacuum dried at 120°C with the vacuum level controlled at 1.0 torr for 4.0 hours. The resulting catalyst is designated Cat-5.

[0102] Example 6

[0103] Place 100.0g of nickel-aluminum alloy-II particles into a vacuum drying oven, control the vacuum degree at 0.5 torr, the temperature at 120℃, and the processing time at 5.0 hours.

[0104] The temperature of the vacuum drying oven was raised to 380℃, and nitrogen and n-octyltriethoxysilane gas were introduced into it. The partial pressure of the n-octyltriethoxysilane gas was 0.1 MPa, the gas flow rate was 600 mL / min, and the gas introduction time was 5.0 hours.

[0105] The temperature of the drying oven was adjusted to 200℃, and the drying oven was purged with nitrogen at a rate of 200 mL / min for 2.0 hours. The resulting modified nickel-aluminum alloy carrier was designated L-6.

[0106] Prepare impregnation solution Q-6 by taking 25.0g of molybdenum dibutyldithiocarbamate, 8.0g of gallium isopropoxide, and 60.0g of n-decane.

[0107] L-6 was impregnated with Q-6, and then vacuum dried at 120°C with the vacuum level controlled at 1.0 torr for 4.0 hours. The resulting catalyst is designated Cat-6.

[0108] Comparative Example 1

[0109] 100.0g of nickel-aluminum alloy-I particles were placed in a vacuum drying oven, with the vacuum level controlled at 0.5 torr, the temperature at 120℃, and the processing time at 5.0 hours. The resulting nickel-aluminum alloy carrier is designated as DL-1.

[0110] Prepare impregnation solution DQ-1 by taking 20.0g of molybdenum diisopropyl dithiocarbamate, 4.0g of zinc diethyl dithiocarbamate, and 75.0g of n-octane.

[0111] DL-1 was impregnated with DQ-1, and then vacuum dried at 120°C with the vacuum level controlled at 1.0 torr for 4.0 hours. The resulting catalyst was designated DCT-1.

[0112] Comparative Example 2

[0113] The preparation method of the modified nickel-aluminum alloy carrier L-3 is the same as in Example 3.

[0114] Prepare solution DQ-2 by taking 20.0g of molybdenum carbonyl, 7.0g of zinc octanoate, and 70.0g of toluene.

[0115] L-3 was impregnated with DQ-2, and then vacuum dried at 120°C with the vacuum level controlled at 1.0 torr for 4.0 hours. The resulting catalyst was in its oxidized state.

[0116] Weigh 20.0g of the above-mentioned oxidized catalyst and place it in a tubular reactor for conventional sulfidation treatment. The treatment conditions are as follows: the sulfidation solution is a cyclohexane solution containing 5.0% dithiodimethyl, the sulfidation solution volume is 40.0g / h, the hydrogen pressure is 4.0MPa, the hydrogen flow rate is 200mL / min, the sulfidation temperature is 340℃, and the sulfidation time is 6.0 hours. The obtained catalyst is designated as DCT-2.

[0117] Comparative Example 3

[0118] The preparation method of the modified nickel-aluminum alloy carrier L-3 is the same as in Example 3.

[0119] Take 12.0g of molybdenum disulfide powder and 2.0g of zinc sulfide powder, dissolve them in a mixed solution of 40.0g of n-octane and 30.0g of DMDS, and prepare an impregnation solution labeled DQ-3.

[0120] L-3 was impregnated with DQ-3, and then vacuum dried at 120°C with the vacuum level controlled at 1.0 torr for 4.0 hours. The resulting catalyst was designated DCT-3.

[0121] Comparative Example 4

[0122] 100.0g of nickel-aluminum alloy-II carrier particles were placed in a vacuum drying oven, with the vacuum level controlled at 0.5 torr, the temperature at 120℃, and the processing time at 5.0 hours. The resulting nickel-aluminum alloy carrier was designated DL-4.

[0123] Prepare impregnation solution DQ-4 by taking 25.0g of molybdenum dibutyldithiocarbamate, 8.0g of gallium isopropoxide, and 60.0g of n-decane.

[0124] DL-4 was impregnated with DQ-4, and then vacuum dried at 120°C with the vacuum level controlled at 1.0 torr for 4.0 hours. The resulting catalyst was designated DCT-4.

[0125] Comparative Example 5

[0126] The preparation method of the modified nickel-aluminum alloy carrier L-6 is the same as in Example 6.

[0127] Prepare solution DQ-5 by taking 22.0g of molybdenum carbonyl, 6.0g of gallium ethoxylate, 60.0g of cyclohexane and 10.0g of ethanol.

[0128] L-6 was impregnated with DQ-5, and then vacuum dried at 120°C with the vacuum level controlled at 1.0 torr for 4.0 hours. This yielded the oxidized catalyst.

[0129] Weigh 20.0g of the above-mentioned oxidized catalyst and place it in a tubular reactor for conventional sulfidation treatment. The treatment conditions are as follows: the sulfidation solution is a cyclohexane solution containing 5.0% dithiodimethyl, the sulfidation solution volume is 40.0g / h, the hydrogen pressure is 4.0MPa, the hydrogen flow rate is 200mL / min, the sulfidation temperature is 340℃, and the sulfidation time is 6.0 hours. The obtained catalyst is designated as DCT-5.

[0130] Comparative Example 6

[0131] The preparation method of the modified nickel-aluminum alloy carrier L-6 is the same as in Example 6.

[0132] Take 13.0g of molybdenum disulfide powder and 6.0g of gallium ethoxylate, dissolve them in a mixed solution of 30.0g of isopropanol and 40.0g of dimethyl disulfide, and prepare an impregnation solution labeled DQ-6.

[0133] L-6 was impregnated with DQ-6, and then vacuum dried at 120°C with the vacuum level controlled at 1.0 torr for 4.0 hours. The resulting catalyst was designated DCT-6.

[0134] Table 1. Composition and properties of the catalysts obtained in each example and comparative example.

[0135]

[0136]

[0137] Examples 7-9

[0138] The catalysts obtained in Examples 1-6 were graded and packed (see Table 3), and the properties of the secondary processed oils used are shown in Table 2. A fixed-bed process was adopted, and the packing volume ratio of hydrodesulfurization catalyst to hydrodenitrification catalyst was 1:1.

[0139] Activation and evaluation of catalysts

[0140] Weigh 20.0g of catalysts Cat-1, Cat-2, Cat-3, Cat-4, Cat-5, and Cat-6 respectively, and place them in a tubular reactor. The activation conditions are: temperature 120℃, hydrogen pressure 0.5MPa, hydrogen flow rate 150.0ml / min, and activation time 2.0 hours.

[0141] Comparative Examples 7-9

[0142] The catalysts obtained from Comparative Examples 1-3 and 4-6 were graded and loaded (Table 3). The properties of the secondary processed oils used are shown in Table 2. A fixed-bed process was adopted, with a loading volume ratio of 1:1 for hydrodesulfurization catalyst to hydrodenitrogenation catalyst.

[0143] 20.0g of catalysts DCT-1, DCT-2, DCT-3, DCT-4, DCT-5, and DCT-6 were weighed and placed into a tubular reactor. The activation conditions were: temperature 120℃, hydrogen pressure 0.5MPa, hydrogen flow rate 150.0mL / min, and activation time 2.0 hours.

[0144] Table 2 Properties of Crude Oil

[0145]

[0146]

[0147] The evaluation conditions were: hydrogen pressure of 10.0 MPa, hydrogen flow rate of 500 mL / min, oil feed rate of 50.0 g / h, and catalyst total volume hourly space velocity of 1.0 h⁻¹. -1 The reaction temperature of the desulfurization catalyst bed was 320℃, and the reaction temperature of the denitrification catalyst bed was 350℃. After 1200 hours of reaction, the sample analysis results are as follows:

[0148] Table 3

[0149]

[0150] The evaluation results show that the hydrodesulfurization catalyst and hydronitrogenation catalyst gradation process of this invention have good hydrodesulfurization, hydronitrogenation and aromatic saturation effects on heavy secondary crude oil.

Claims

1. A method for hydrotreating inferior oil, employing a fixed-bed hydrotreating process, wherein, in the presence of hydrogen, the inferior oil is sequentially contacted with at least one hydrodesulfurization catalyst and at least one hydrodenitrogenation catalyst to undergo a hydrotreating reaction, yielding hydrotreated oil; characterized in that, The hydrodesulfurization catalyst comprises a hydrodesulfurization support, an active component, and an auxiliary agent. The hydrodesulfurization support comprises an organosilicon-modified nickel-aluminum alloy, the active component is an organomolybdenum, wherein the organomolybdenum is alkyl dithiophosphate molybdenum and / or alkyl dithiocarbamate molybdenum, and the auxiliary agent is an organozinc, wherein the organozinc is alkyl dithiophosphate zinc and / or alkyl dithiocarbamate zinc. The hydrodenitrogenation catalyst comprises a hydrodenitrogenation support and an active component. The hydrodenitrogenation support comprises an organosilicon-modified nickel-aluminum alloy, the active component comprises an organomolybdenum, wherein the organomolybdenum is alkyl dithiophosphate molybdenum and / or alkyl dithiocarbamate molybdenum; the hydrodenitrogenation catalyst includes an organogallium auxiliary agent.

2. The method according to claim 1, characterized in that, The alkyl dithiophosphate molybdenum in the hydrodesulfurization catalyst and the hydrodenitrogenation catalyst are each independently selected from one or more of diisopropyl molybdenum dithiophosphate, dibutyl molybdenum dithiophosphate oxysulfide, and diisooctyl molybdenum dithiophosphate; the alkyl dithiocarbamate molybdenum in the hydrodesulfurization catalyst and the hydrodenitrogenation catalyst are each independently selected from one or more of dibutyl molybdenum dithiocarbamate and diisopropyl molybdenum dithiocarbamate.

3. The method according to claim 1, characterized in that, In the hydrodesulfurization catalyst, the alkyl dithiophosphate zinc is selected from one or more of dibutyl dithiophosphate zinc, isodecyl dithiophosphate zinc, diisooctyl dithiophosphate zinc, and di(tetradecyl)alkyl dithiophosphate zinc; the alkyl dithiocarbamate zinc is selected from one or more of diethyl dithiocarbamate zinc, ethylphenyl dithiocarbamate zinc, and dibutyl dithiocarbamate zinc.

4. The method according to claim 1, characterized in that, In the hydrogenation denitrification catalyst, the organogallium is one or more of triethylgallium, triisopropylgallium, tritert-butylgallium, gallium acetylacetone, gallium ethoxy, and gallium isopropoxide.

5. The method according to claim 1, characterized in that, In the hydrodesulfurization catalyst or hydrodenitrogenation catalyst, the organosilicon is specifically an alkoxysilane.

6. The method according to claim 5, characterized in that, The alkoxysilane is selected from at least one of methyltrimethoxysilane, triethoxysilane, methyltriethoxysilane, propyltrimethoxysilane, butyltriethoxysilane, and octyltriethoxysilane.

7. The method according to claim 1, characterized in that, Based on the dry total weight of the hydrodesulfurization catalyst, the content of Al (calculated as aluminum oxide) is 62%~84%, the content of Ni (calculated as nickel oxide) is 8%~18%, the content of molybdenum (calculated as molybdenum trioxide) is 6%~18%, the content of silicon (calculated as silicon dioxide) is 0.2%~3%, and the content of additives (calculated as metal oxides) is 1.5%~7%.

8. The method according to claim 7, characterized in that, Based on the dry total weight of the hydrodesulfurization catalyst, the content of Al (calculated as aluminum oxide) is 68%~80%, the content of Ni (calculated as nickel oxide) is 9%~15%, the content of molybdenum (calculated as molybdenum trioxide) is 8%~17%, the content of silicon (calculated as silicon dioxide) is 0.5%~2%, and the content of additives (calculated as metal oxides) is 2%~5.5%.

9. The method according to claim 1, characterized in that, Based on the dry total weight of the hydrodenitrification catalyst, the content of Al (calculated as aluminum oxide) is 62%~84%, the content of Ni (calculated as nickel oxide) is 8%~18%, the content of molybdenum (calculated as molybdenum trioxide) is 6%~18%, the content of silicon (calculated as silicon dioxide) is 0.2%~3%, and the content of additives (calculated as metal oxides) is 1.5%~7%.

10. The method according to claim 9, characterized in that, Based on the dry total weight of the hydrodenitrification catalyst, the content of Al (calculated as aluminum oxide) is 68%~80%, the content of Ni (calculated as nickel oxide) is 9%~15%, the content of molybdenum (calculated as molybdenum trioxide) is 8%~17%, the content of silicon (calculated as silicon dioxide) is 0.5%~2%, and the content of additives (calculated as metal oxides) is 2%~5.5%.

11. The method according to claim 1, characterized in that, The preparation method of the hydrodesulfurization catalyst includes: An impregnation solution containing active components and additives is prepared and then impregnated onto an organosilicon-modified nickel-aluminum alloy carrier. After drying, a hydrodesulfurization catalyst is obtained.

12. The method according to claim 11, characterized in that, The method for modifying the organosilicon-based nickel-aluminum alloy carrier includes: contacting the nickel-aluminum alloy with alkoxysilane gas to perform silicon modification.

13. The method according to claim 12, characterized in that, The nickel-aluminum alloy was subjected to vacuum treatment before silicone modification and to displacement treatment after silicone modification.

14. The method according to claim 11 or 12, characterized in that, The preparation method of the hydrodesulfurization catalyst includes: (a) Vacuum treatment of the nickel-aluminum alloy carrier; (b) Introduce alkoxysilane gas into the carrier treated in step (a) for modification treatment; (c) Replace the alkoxysilane gas described in step (b) with nitrogen and / or an inert gas to obtain a modified nickel-aluminum alloy carrier; (d) Prepare an impregnation solution containing active components and additives, and then impregnate it onto the modified nickel-aluminum alloy support obtained in step (c). After drying, a hydrodesulfurization catalyst is obtained.

15. The method according to claim 14, characterized in that, In step (a), based on the total amount of the nickel-aluminum alloy, the aluminum content is 50wt%~95wt% and the nickel content is 5wt%~50wt%; based on the total amount of the nickel-aluminum alloy, the aluminum content is 70wt%~90wt% and the nickel content is 10wt%~30wt%.

16. The method according to claim 14, characterized in that, In step (a), the conditions for vacuuming are: vacuum degree of 0.05-1.0 torr, processing time of 2-10 hours, and temperature of 50-140℃.

17. The method according to claim 16, characterized in that, In step (a), the conditions for vacuuming are: vacuum degree of 0.1-0.5 torr, processing time of 4-8 hours, and temperature of 60-120℃.

18. The method according to claim 14, characterized in that, The alkoxysilane gas is selected from one or more of methyltrimethoxysilane, triethoxysilane, methyltriethoxysilane, propyltrimethoxysilane, isobutyltriethoxysilane, and n-octyltriethoxysilane.

19. The method according to claim 14, characterized in that, In step (d), the active component and the auxiliary agent are mixed with a solvent to prepare an impregnation solution; the solvent is one or a mixture of several of n-hexane, n-heptane, n-octane or n-nonane; in the impregnation solution, the concentration of the active component and the auxiliary agent is independently 0.1~3 mol / L.

20. The method according to claim 1, characterized in that, The method for preparing the hydrodenitrification catalyst includes the following steps: (1) Preparation of organosilicon-modified nickel-aluminum alloy carrier; (2) Prepare an impregnation solution containing active components and additives, impregnate it onto the silicon-modified nickel-aluminum alloy support obtained in step (1), and dry it to obtain a hydrodenitrification catalyst.

21. The method according to claim 20, characterized in that, In step (1), the method for modifying the nickel-aluminum alloy carrier with organosilicon includes: contacting the nickel-aluminum alloy with a gaseous organosilicon compound to modify it with silicon.

22. The method according to claim 20, characterized in that, The method for modifying the nickel-aluminum alloy carrier with organosilicon includes: evacuating the nickel-aluminum alloy carrier under vacuum, then introducing a gaseous organosilicon compound for organosilicon modification, and then introducing nitrogen and / or an inert gas for replacement, thereby obtaining the organosilicon-modified nickel-aluminum alloy carrier.

23. The method according to claim 21 or 22, characterized in that, Based on the total amount of the nickel-aluminum alloy, the aluminum content is 50wt%~95wt% and the nickel content is 5wt%~50wt%.

24. The method according to claim 23, characterized in that, Based on the total amount of the nickel-aluminum alloy, the aluminum content is 70wt%~90wt% and the nickel content is 10wt%~30wt%.

25. The method according to claim 22, characterized in that, The vacuuming process is carried out at a temperature of 50-200℃, a vacuum degree of 0.05-1.0 torr, and a processing time of 2-10 hours.

26. The method according to claim 25, characterized in that, The vacuuming process is carried out at a temperature of 80-150℃, with a vacuum level of 0.1-0.5 torr, and for a duration of 4-8 hours.

27. The method according to claim 21 or 22, characterized in that, The gaseous organosilicon compound is a gaseous alkoxysilane, which is one or more of methyltrimethoxysilane, triethoxysilane, methyltriethoxysilane, propyltrimethoxysilane, isobutyltriethoxysilane, and n-octyltriethoxysilane.

28. The method according to claim 20, characterized in that, In step (2), the active component and the auxiliary agent are mixed with a solvent to prepare an impregnation solution; the solvent is one or a mixture of several of the following: n-hexane, n-heptane, n-octane, n-nonane, cyclohexane, ethanol, methanol, and isopropanol; in the impregnation solution, the concentration of the active component and the auxiliary agent is independently 0.1~3 mol / L.

29. The method according to claim 1, characterized in that, The operating conditions for the fixed-bed hydrogenation process are as follows: reaction hydrogen pressure is 2.0-20.0 MPa, hydrogen-to-oil volume ratio is 200:1-1500:1, and volume hourly space velocity is 0.2-3.0 h⁻¹. -1 Reaction temperature: 280-380℃ for desulfurization catalyst bed and 300-400℃ for denitrification catalyst bed.

30. The method according to claim 29, characterized in that, The operating conditions for the fixed-bed hydrogenation process are as follows: reaction hydrogen pressure is 6.0-16.0 MPa, hydrogen-to-oil volume ratio is 500:1-1200:1, and volume hourly space velocity is 0.5-2.0 h⁻¹. -1 Reaction temperature: 300-360℃ for desulfurization catalyst bed and 320-380℃ for denitrification catalyst bed.

31. The method according to claim 1, characterized in that, The inferior oil is a secondary processed oil with the following properties: nitrogen content of 300-3000 μg / g, sulfur content of 2000-30000 μg / g, and aromatic content of 15wt%-80wt%.

32. The method according to claim 1, characterized in that, The inferior oil is a secondary processed oil with the following properties: aromatic content of 30wt%-70wt%.

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