Hydrogenation catalyst grading system and its use, and method for grading hydrogenation catalyst

Abstract

The present invention relates to the field of hydrogenation of oil products, and relates to a hydrogenation catalyst grading system and its use, as well as a hydrogenation catalyst grading method. The system of the present invention includes M hydrogenation catalysts packed sequentially along the direction of material flow, M is an integer of 2 or more, the R value of the Nth hydrogenation catalyst is equal to or greater than the R value of the N-1th hydrogenation catalyst, and the R value of at least one Nth hydrogenation catalyst is greater than the R value of the N-1th hydrogenation catalyst, N is an integer of 2 to M, and the R value is the ratio between the molar content of Group VIII metal elements in the hydrogenation catalyst characterized by X-ray photoelectron spectroscopy spectrum and the weight content of Group VIII metal elements in terms of oxides in the hydrogenation catalyst characterized by X-ray fluorescence spectrum. The hydrogenation catalyst grading system of the present invention is advantageous in improving the denitrification effect of the entire device and improving the hydrogenation saturation of the catalyst system by grading hydrogenation catalysts with different nickel atomic concentrations on the surface.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application is a Chinese patent application filed on October 25, 2021 202111242776.0 The benefit of this application is claimed, the contents of which are incorporated herein by reference.

[0002] [Technical Field] The present invention relates to the field of oil product hydrogenation, and to a hydrogenation catalyst grading system and its use, as well as a method for grading a hydrogenation catalyst. [Background technology]

[0003] In modern petroleum refining technology, hydrocracking refers to a hydrogenation process that converts more than 10% of the high molecular weight compounds in the raw material into low molecular weight compounds through hydrogenation reactions. It is characterized by high adaptability to raw materials, flexible production schemes, and good product quality. It can directly convert a variety of low-quality heavy feedstocks into high-quality jet fuel, diesel, lubricating oil base stock, chemical naphtha, and tail oil steam cracking feedstock for ethylene production, which are urgently needed in the market. This has become one of the most important heavy oil deep-processing processes in the modern petroleum refining and petrochemical industries, and is increasingly widely used both at home and abroad.

[0004] The core of hydrocracking technology is catalysts, including pretreatment catalysts and cracking catalysts. The main functions of hydrocracking pretreatment catalysts are as follows: to remove impurities such as sulfur, nitrogen, oxygen, and heavy metals from the feedstock through hydrogenation, and to saturate polycyclic aromatic hydrocarbons through hydrogenation, thereby improving the characteristics of petroleum products. Because nitrogen compounds, especially basic nitrogen compounds, in the feedstock can poison the acid centers of the cracking catalyst, hydrodenitrification performance is an important indicator for evaluating hydrocracking pretreatment catalysts.

[0005] Industrial equipment is an adiabatic reactor. As the reaction progresses, the reaction temperature rises significantly, the hydrogen partial pressure drops, the hydrogen sulfide and ammonia partial pressures increase, the nitrogen content in the reactants decreases, and the remaining nitrogen-containing compounds are molecules that are difficult to denitrify and generally have multiple side chains. There are significant differences in the reaction conditions between the upper and lower catalyst beds. To address these differences in reaction environment, a catalyst grading system can be developed to maximize catalyst performance and extend catalyst life.

[0006] CN112725014A discloses a method for grading hydrogenation catalysts, which involves filling N catalyst beds, where N is an integer greater than 2. The catalyst packed into the mth catalyst bed has the highest acid content between 250°C and 500°C, where m is an integer greater than 1 and less than N. The catalysts packed into the 1st to mth catalyst beds tend to have an increasing acid content between 250°C and 500°C, while the catalysts packed into the mth to Nth catalyst beds tend to have a decreasing acid content between 250°C and 500°C. The reaction temperature of the catalyst beds tends to increase along the flow. This method not only improves the overall denitrification and desulfurization performance of the hydrotreating reactor, but also improves the performance stability of the catalyst system.

[0007] CN109718867A relates to the field of hydrotreating catalysts and discloses a hydrotreating catalyst system and its use, a method for producing a hydrotreating catalyst, and a method for hydrotreating a distillate oil. The catalyst system includes a first catalyst bed and a second catalyst bed, the first catalyst containing alumina, a hydrodesulfurization catalytically active component, and a carboxylic acid, the second catalyst containing an inorganic refractory component, a hydrodesulfurization catalytically active component, and a carboxylic acid, and the second inorganic refractory component containing amorphous silicon aluminum and / or a molecular sieve and alumina. The first and second catalysts have pore diameters of 4-40 nm and 100-300 nm, respectively, with the pore volume of the pores with diameters of 4-40 nm accounting for 60-95% of the total pore volume and the pore volume of the pores with diameters of 100-300 nm accounting for 0.5-50% of the total pore volume. The first and second catalysts have pore sizes of 100-300 nm, which provide excellent performance, shorten the manufacturing process, and improve the catalytic system's ability to process distillate oil.

[0008] CN106669861A discloses a method for grading hydrocracking catalysts and catalysts for a diesel hydroconversion process. The hydrocracking catalyst grading method of the present invention involves dividing a hydrocracking reactor into two to eight reaction zones along the material flow direction, and packing each reaction zone with a mixture of hydrocracking catalyst and regenerated catalyst. The mass ratio of hydrocracking catalyst to regenerated catalyst in each reaction zone is 10:1 to 1:10, and the mass ratio of hydrocracking catalyst to regenerated catalyst in each reaction zone gradually decreases along the material flow direction. A diesel hydroconversion process utilizing the above catalyst grading is also provided. By grading and packing catalysts with different reaction characteristics in the cracking reactor, the hydrogenation selectivity of diesel / gasoline components during the conversion process is improved, resulting in an increased yield of high-octane gasoline products. Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention provides a hydrogenation catalyst grading system, its use, and a hydrogenation catalyst grading method. By using the hydrogenation catalyst grading system of the present invention in the hydrogenation process of oil products, the overall denitrification performance and aromatic hydrocarbon saturation can be improved. [Means for solving the problem]

[0010] A first aspect of the present invention includes M hydrogenation catalysts packed sequentially along the direction of material flow, where M is an integer of 2 or more; the R value of the Nth hydrogenation catalyst is equal to or greater than the R value of the (N-1)th hydrogenation catalyst, and the R value of at least one Nth hydrogenation catalyst is greater than the R value of the (N-1)th hydrogenation catalyst, N being an integer of 2 or more and M or less; The R-value provides a grading system for hydrogenation catalysts, which is the ratio of the molar content of Group VIII metal elements in the hydrogenation catalyst characterized by X-ray photoelectron spectroscopy spectrum to the weight content of Group VIII metal elements in terms of oxides in the hydrogenation catalyst characterized by X-ray fluorescence spectrum.

[0011] Preferably, the R value of the Nth hydrogenation catalyst is 1% to 20%, preferably 2% to 10%, higher than the R value of the N-1th hydrogenation catalyst.

[0012] A second aspect of the present invention provides the use of a hydrogenation catalyst grading system according to the first aspect in the hydrotreating of an oil product, preferably in the hydrocracking of an oil product, more preferably in the hydrocracking pretreatment of an oil product.

[0013] A third aspect of the present invention provides a method for grading a hydrogenation catalyst, which is carried out in the grading system for a hydrogenation catalyst according to the first aspect.

[0014] Preferably, the reaction temperature of the Nth hydrogenation catalyst bed is equal to or greater than the reaction temperature of the first hydrogenation catalyst bed. [Effects of the Invention]

[0015] The hydrogenation catalyst grading system of the present invention grades hydrogenation catalysts with different nickel atomic concentrations on the surface, thereby enhancing the denitrification effect of the entire apparatus and improving the hydrogenation saturation of the catalyst system. DETAILED DESCRIPTION OF THE INVENTION

[0016] The endpoints of ranges and any values ​​disclosed herein are not intended to be limiting to the exact ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. In the case of numerical ranges, values ​​between the individual range endpoints, between the individual range endpoints and the individual point values, and between the individual point values ​​can be combined with each other to form one or more new numerical ranges, and these numerical ranges should be considered to be specifically disclosed herein.

[0017] A first aspect of the present invention includes M hydrogenation catalysts packed sequentially along the direction of material flow, where M is an integer of 2 or more; the R value of the Nth hydrogenation catalyst is equal to or greater than the R value of the (N-1)th hydrogenation catalyst, and the R value of at least one Nth hydrogenation catalyst is greater than the R value of the (N-1)th hydrogenation catalyst, N being an integer of 2 or more and M or less; The R-value provides a grading system for hydrogenation catalysts, which is the ratio of the molar content of Group VIII metal elements in the hydrogenation catalyst characterized by X-ray photoelectron spectroscopy spectrum to the weight content of Group VIII metal elements in terms of oxides in the hydrogenation catalyst characterized by X-ray fluorescence spectrum.

[0018] Unless otherwise specified, the content of a Group VIII metal element in a hydrogenation catalyst characterized by X-ray photoelectron spectroscopy spectrum refers to the mole percentage content of the Group VIII metal element in elemental terms in a hydrogenation catalyst characterized by X-ray photoelectron spectroscopy spectrum.

[0019] In the present invention, X-ray photoelectron spectroscopy (XPS) measurements are performed using a MultiLab 2000 X-ray photoelectron spectrometer manufactured by Thermo Fisher Scientific, with MgKα as the excitation source and C1s (284.8 eV) as the internal standard to calibrate the charge effect.

[0020] Unless otherwise specified, the content of Group VIII metal elements in a hydrogenation catalyst characterized by X-ray fluorescence spectroscopy (XRF) refers to the weight percentage content of Group VIII metal elements in terms of oxides in a hydrogenation catalyst characterized by X-ray fluorescence spectroscopy.

[0021] In this invention, a Rigaku ZSX100e wavelength dispersive X-ray fluorescence spectrometer is used to characterize the X-ray fluorescence spectra (XRF). Elements such as aluminum and silicon are analyzed using a PET analyzing crystal, and elements such as Ni, Co, Mo, and W are analyzed using a LiF1 analyzing crystal. The results are then normalized using the standard-less sample analysis software ZSX.

[0022] According to the present invention, the grading system of the present invention includes M hydrogenation catalysts packed sequentially along the direction of material flow. There is no particular limitation on the specific packing method, and the M hydrogenation catalysts may be packed into M hydrogenation catalyst beds, and two or more of the hydrogenation catalysts may be packed into one hydrogenation catalyst bed, as long as the material can be contacted sequentially with the M hydrogenation catalysts. In the present invention, the arrangement of the hydrogenation catalyst beds is not particularly limited, and they may be arranged in the same hydrogenation reactor or in two or more hydrogenation reactors connected in series, as long as it is possible to ensure that the M hydrogenation catalysts are packed sequentially along the direction of material flow.

[0023] In the present invention, the R values ​​of the hydrogenation catalysts sequentially loaded along the material flow direction show an increasing trend, i.e., the R value of the Nth catalyst is equal to or greater than the R value of the (N-1)th hydrogenation catalyst. Here, the R value showing an increasing trend means that the system as a whole shows an increasing trend, but the R value of one or more loaded hydrogenation catalysts is allowed to be the same as or similar to the R value of the previous hydrogenation catalyst.

[0024] The phrase "the R value of at least one Nth hydrogenation catalyst is greater than the R value of the (N-1)th hydrogenation catalyst" used in the present invention means that the R value of at least one (Nth) hydrogenation catalyst loaded subsequently in the entire system is greater than the R value of the (N-1)th hydrogenation catalyst loaded previously.

[0025] In the present invention, the loading of the hydrogenation catalyst and the arrangement of the hydrogenation catalyst bed are not particularly limited, and those skilled in the art can realize the embodiments of the present invention by any means, which are all within the protection scope of the grading system of the present invention.

[0026] In the present invention, the range of the value of M is wide, that is, the range of the number of hydrogenation catalysts packed in the grading system is wide. In consideration of both efficiency and economy, M is preferably an integer of 3 or more, and may be an integer of 3 to 10, for example, 3, 4, 5, 6, 7, 8, 9, or 10, but is preferably 3 to 7.

[0027] According to one preferred embodiment of the present invention, the R value of the Nth hydrogenation catalyst is 1% to 20%, preferably 2% to 10%, higher than the R value of the (N-1)th hydrogenation catalyst, which contributes to improving the hydrodenitrification capacity and aromatic hydrocarbon saturation capacity of the grading system.

[0028] According to the grading system of the present invention, the content of Group VIII metal elements in terms of molar content in the hydrogenation catalyst characterized by X-ray photoelectron spectroscopy spectrum is preferably 0.1 to 6%, more preferably 0.5 to 3%.

[0029] According to the grading system of the present invention, the content of Group VIII metal elements by oxide weight in the hydrogenation catalyst characterized by X-ray fluorescence spectrum is preferably 1-15%, more preferably 1.5-10%.

[0030] According to one preferred embodiment of the present invention, the R value of the hydrogenation catalyst is 3 to 150%, preferably 10 to 50%.

[0031] According to one preferred embodiment of the present invention, the reduction temperature of the (N-1)th hydrogenation catalyst is equal to or higher than the reduction temperature of the (N)th hydrogenation catalyst, and the reduction temperature of the hydrogenation catalyst refers to the peak-top temperature of the reduction peak characterized by H-TPR. In this preferred embodiment, for M hydrogenation catalysts sequentially packed along the material flow direction, the reduction temperatures of the hydrogenation catalysts tend to decrease, where the decrease in reduction temperature means that the system as a whole tends to decrease, but the reduction temperature of one or more hydrogenation catalysts is allowed to be the same or similar to the reduction temperature of the previous hydrogenation catalyst.

[0032] Preferably, the reduction temperature of the N-1th hydrogenation catalyst bed is 5 to 150°C, more preferably 10 to 50°C higher than the reduction temperature of the Nth hydrogenation catalyst bed.

[0033] In the present invention, the reduction temperature of the hydrogenation catalyst is obtained by characterizing it with H2-TPR. Specifically, a fully automated chemical adsorption apparatus (AMI-200 model) manufactured by Altamira, USA, is used for the H2-TPR characterization. High-purity argon gas is used as the carrier gas, and 5% by volume of H2-Ar is used as the reactant gas. The temperature is raised to 700°C at a heating rate of 10°C / min.

[0034] Preferably, the reduction temperature of the first hydrogenation catalyst packed is 350 to 550°C.

[0035] In the present invention, the loading amount of each hydrogenation catalyst is not particularly limited, and a person skilled in the art may appropriately determine it based on the above disclosure. Preferably, the loading volume ratio of adjacent hydrogenation catalysts is 1:20 to 20:1, preferably 1:10 to 10:1, and more preferably 1:5 to 5:1.

[0036] In the grading system according to the present invention, the support and active component of each hydrogenation catalyst may be the same or different. The composition of the hydrogenation catalyst is not particularly limited, and any catalyst that can be used in hydrotreating reactions in the art can be used in the present invention. Preferably, each hydrogenation catalyst independently contains a support, a Group VIB metal active component, and a Group VIII metal active component.

[0037] Preferably, the Group VIB metal active component is W and / or Mo, and the Group VIII metal active component is Ni and / or Co.

[0038] The support may be any of various inorganic heat-resistant oxides commonly used in the art, and preferably, the support is at least one selected from alumina, silica, silica-alumina, magnesium oxide, zirconia, boron oxide, and titanium dioxide.

[0039] In the present invention, the support may further contain a doping element, and the doping element may be, for example, one or more of elements such as phosphorus, silicon, boron, fluorine, sodium, etc. The amount of the doping element added may be a normal amount, but preferably accounts for 0.5% to 6% of the mass of the support.

[0040] In the present invention, the composition range of each hydrogenation catalyst is broad and can be varied or adjusted over a wide range, as long as it satisfies the trends in the above-mentioned grading system. The contents of the Group VIB metal active component and the Group VIII metal active component in each hydrogenation catalyst may be the same or different. Along the material flow direction, the contents of the Group VIII metal active component and the Group VIB metal active component in different hydrogenation catalysts may independently show trends of low to high, high to low, stable, or irregular, but the present invention does not particularly limit this. Preferably, the contents of the Group VIII metal active component and the Group VIB metal active component in the Nth hydrogenation catalyst are equal to or greater than the contents of the Group VIII metal active component and the Group VIB metal active component in the N-1th hydrogenation catalyst.

[0041] Preferably, the content of the Group VIB metal active component calculated as an oxide is 9 to 50% by weight, and the content of the Group VIII metal active component calculated as an oxide is 1 to 15% by weight, based on the total weight of the hydrogenation catalyst.

[0042] In the grading system according to the present invention, the loaded hydrogenation catalyst may be a commercially available product or may be prepared by any conventional catalyst preparation technique. For example, the distribution of Group VIII metal atoms can be improved and the reduction temperature of the hydrogenation catalyst can be controlled by introducing various inorganic or organic additives during the preparation process of the support and catalyst, or by changing the heat treatment temperature of the catalyst. Taking the introduction of various inorganic or organic additives during the preparation process of the support and catalyst as an example, the inorganic additive may be one or more of fluorine, silicon, phosphorus, boron, magnesium, zirconium, etc., and the organic additive may be one or more of nitrogen-containing organic compounds, sulfur-containing organic compounds, and oxygen-containing organic compounds. The inorganic or organic additive may be introduced at any step, such as before, simultaneously with, or at any one or more steps after impregnation with the Group VIB and Group VIII metal components. The nitrogen-containing organic compound may be an organic compound containing at least one covalently bonded nitrogen atom, such as ethanolamine, diethanolamine, triethanolamine, ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), and cycloethylenediaminetetraacetic acid. The sulfur-containing organic compound may be an organic compound containing at least one covalently bonded sulfur atom, such as a thiol (general formula R-SH), a thioether (general formula R-SR), or a disulfide (general formula R-SR). R in these sulfur-containing organic compounds may be an alkyl group containing 1 to 10 carbon atoms, such as ethyl mercaptan, ethyl propyl sulfide, or dimethyl disulfide. The sulfur-containing organic compound may contain one or more carboxyl, carbonyl, ester, ether, hydroxyl, or mercapto group substitutions, such as thioglycolic acid, mercaptopropionic acid, or dimercaptopropanol. In addition to the above sulfur-containing organic compounds, sulfone and sulfoxide compounds, such as dimethyl sulfoxide and dimethyl sulfone, may also be included. The oxygen-containing organic compound is an organic substance containing at least one carbon atom and one oxygen atom. The oxygen-containing moiety may be a carboxyl, carbonyl, or hydroxyl moiety, or a combination thereof.These substances may be acids such as acetic acid, oxalic acid, malonic acid, tartaric acid, malic acid, citric acid, etc.; alcohols such as ethylene glycol, propylene glycol, butylene glycol, glycerin, trimethylolethane, etc.; ethers such as diethylene glycol, dipropylene glycol, triethylene glycol, tributyl glycol, tetraethylene glycol, polyethylene glycol, etc.; sugars such as glucose, fructose, lactose, maltose, sucrose, etc.; ketones; phenols; aldehydes, and lipids.

[0043] The heat treatment temperature of drying and / or roasting also has a significant effect on the concentration of Group VIII metal atoms on the surface of the hydrogenation catalyst. Taking Ni as an example, when treated at a low temperature, the nickel atom concentration on the surface of the hydrogenation catalyst is high and the reduction temperature of the resulting hydrogenation catalyst is low for the same mass content of nickel element. When treated at a high temperature, the nickel atom concentration on the surface of the hydrogenation catalyst is low and the reduction temperature of the resulting hydrogenation catalyst is high for the same mass content of nickel element. The terms low temperature and high temperature are relative, and the treatment temperature range is 80 to 700°C. For example, a heat treatment temperature of 80 to 300°C, preferably 120 to 200°C, is considered to be a low-temperature treatment, while a heat treatment temperature of 350 to 800°C, preferably 400 to 600°C, is considered to be a high-temperature treatment.

[0044] A second aspect of the present invention provides use of the hydrogenation catalyst grading system according to the first aspect in the hydrotreating of oil products, preferably in the hydrocracking of oil products, more preferably in the pretreatment of hydrocracking of oil products. The use of the grading system according to the present invention in the pretreatment of hydrocracking of oil products can remove as many impurities as possible from the oil products, such as sulfur, nitrogen, oxygen, and heavy metals, while also hydrosaturating polycyclic aromatic hydrocarbons, improving the properties of the oil products and enabling the hydrocracking pretreatment to perform its intended function.

[0045] A third aspect of the present invention provides a method for grading a hydrogenation catalyst, which is carried out in the hydrogenation catalyst grading system according to the first aspect.

[0046] Preferably, this method includes a step of introducing the oil product to be hydrotreated into the grading system to carry out a hydrogenation reaction. Specifically, the oil product to be hydrotreated is introduced into the grading system and brought into contact with a first hydrogenation catalyst packed therein, and then successively brought into contact with the hydrogenation catalysts packed in the grading system to undergo a reaction.

[0047] Preferably, the hydrogenation reaction conditions are a reaction pressure of 3 to 20 MPa and a total liquid hourly space velocity of 0.2 to 4 h -1 and a reaction temperature of 260 to 430°C. More preferably, the conditions for the hydrogenation reaction include a reaction pressure of 8 to 17 MPa and a total liquid hourly space velocity of 0.8 to 2 h -1 , reaction temperature 300-400°C.

[0048] The method of the present invention can process feedstocks including petroleum fractions, coal-based liquid oil, biomass oil, shale oil, coal tar, etc., and preferably processes petroleum fractions including, but not limited to, at least one of diesel, VGO, CGO, and DAO, etc. The main properties of the feedstock are preferably an initial boiling point of 180°C or higher, a final boiling point of 600°C or lower, and a density of 0.8 to 0.95 g cm. -3 (20°C), nitrogen content 100 to 6000 μg g -1 , a sulfur content of 0.05 to 3 wt. %, and a total aromatic hydrocarbon content of 20 to 80 wt. %.

[0049] According to the method of the present invention, preferably, said hydrogenation reaction includes at least one of, but is not limited to, hydrodesulfurization, hydrodenitrification, hydrodeoxygenation, and hydrosaturation.

[0050] According to the method of the present invention, the reaction temperature of the Nth hydrogenation catalyst bed is preferably equal to or higher than the reaction temperature of the 1st hydrogenation catalyst bed, more preferably equal to or higher than the reaction temperature of the N-1th hydrogenation catalyst bed, and is preferably 5 to 50°C, for example, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, or a range consisting of any two of these. As a result of research, the present inventors have found that the above-mentioned reaction temperature change tendency of a hydrogenation catalyst grading system having a specific distribution of Group VIII metal elements is more advantageous for improving the hydrodenitrification performance and the hydrogenation saturation performance of the grading system for aromatic hydrocarbons.

[0051] In the present invention, the Nth hydrogenation catalyst bed is the hydrogenation section formed by the Nth hydrogenation catalyst.

[0052] In the present invention, in an industrial device, the reaction temperature refers to the average reaction temperature. Hydrogenation is an exothermic reaction, and the temperature of the hydrogenation catalyst bed gradually increases. The algebraic sum of the temperatures of each catalyst segment is obtained and divided by the number of segments, which is recorded as the average reaction temperature. In laboratory evaluation or small-scale equipment, if the reaction temperature is fixed and the operation is isothermal, the reaction temperature will be the fixed reaction temperature.

[0053] Preferably, the reaction temperature of the final hydrogenation catalyst bed is 410° C. or less, for example, 370 to 410° C. According to such a preferred embodiment, the stability of the hydrogenation catalyst in the grading system is further ensured. [Example]

[0054] The grading system and its use according to the present invention will be further described below with reference to examples and comparative examples, but the following examples do not limit the system and method of the present invention.

[0055] In the hydrogenation catalysts of the following Examples and Comparative Examples, the R value is the ratio of the content of Group VIII metal elements in the hydrogenation catalyst characterized by X-ray photoelectron spectroscopy spectrum to the content of Group VIII metal elements in the hydrogenation catalyst characterized by X-ray fluorescence spectroscopy. The methods for characterizing the X-ray photoelectron spectroscopy spectrum and the X-ray fluorescence spectrum are as described above. The reduction temperature is measured by H-TPR as described above.

[0056] In the following examples and comparative examples, all %'s are mass percentages unless otherwise specified.

[0057] The following preparation examples illustrate the preparation of hydrogenation catalysts. The properties of the supports used in the following preparation examples are given in Table 1 below.

[0058] [Table 1]

[0059] Manufacturing Example 1 Manufacturing method of catalyst A: Alumina support Z was impregnated with an equal volume of an impregnation solution containing Mo and Ni. The impregnation solution contained diethylene glycol and citric acid so that the molar ratio to nickel atoms was 0.5:0.5:1. The catalyst was dried at 120°C for 3 hours and roasted at 540°C for 2 hours. The resulting catalyst was designated as catalyst A. Manufacturing method of catalyst B: Alumina support Z was impregnated with an equal volume of an impregnation solution containing Mo and Ni. The impregnation solution contained diethylene glycol and citric acid so that the molar ratio to nickel atoms was 0.5:0.5:1. The catalyst was dried at 120°C for 3 hours and roasted at 440°C for 2 hours. The catalyst obtained was designated as catalyst B. Manufacturing method of catalyst C: Alumina support Z was impregnated with an equal volume of an impregnation solution containing Mo and Ni. The impregnation solution contained diethylene glycol and citric acid so that the molar ratio with respect to nickel atoms was 0.5:0.5:1. The catalyst was dried at 120°C for 3 hours and named catalyst C. Manufacturing method of catalyst D: Alumina support Z was impregnated with an equal volume of an impregnation solution containing Mo and Ni. The impregnation solution contained diethylene glycol and citric acid so that the molar ratio to nickel atoms was 0.5:0.5:1. The catalyst was dried at 120°C for 3 hours and named catalyst D.

[0060] The properties of the catalyst prepared in Preparation Example 1 are shown in Table 2 below.

[0061] [Table 2]

[0062] Example 1 In this embodiment, a grading method for the grading system according to the present invention will be described. The grading system includes three hydrogenation catalyst beds arranged along the direction of material flow, with bed volumes of 30 mL, 30 mL, and 30 mL, respectively, and reaction temperatures controlled at 340°C, 360°C, and 380°C, respectively. When the test number is PS1, catalyst A, catalyst B, and catalyst C are sequentially loaded into three reaction beds along the direction of reactant flow. When the test number is PS2, the three reaction beds are sequentially filled with catalyst A, catalyst A, and catalyst C along the direction of the reactant flow. When the test number is PS3, the three reaction beds are sequentially filled with catalyst B, catalyst B, and catalyst C along the direction of the reactant flow. When the test number is PS4, catalyst A, catalyst B, and catalyst D are sequentially loaded into three reaction beds along the direction of reactant flow.

[0063] Example 2 This example describes a grading system and a grading method according to the present invention. The grading system includes four hydrogenation catalyst beds arranged in the same fixed-bed hydrogenation reactor along the direction of material flow. The four reaction beds in the direction of reaction material flow are sequentially filled with catalyst A, catalyst B, catalyst D, and catalyst C. The bed volumes are 10 mL, 20 mL, 30 mL, and 30 mL, respectively. The reaction temperatures are controlled at 330°C, 345°C, 360°C, and 380°C, respectively.

[0064] Comparative Example 1 The grading system includes three hydrogenation catalyst beds arranged in the same fixed-bed hydrogenation reactor along the direction of material flow, with bed volumes of 30 mL, 30 mL, and 30 mL, respectively, and reaction temperatures controlled at 340°C, 360°C, and 380°C, respectively. When the test number is PD1, the catalyst C, catalyst B, and catalyst A are sequentially loaded into three reaction beds along the direction of reactant flow. When the test number is PD2, the three reaction beds are sequentially filled with catalyst B, catalyst B, and catalyst B along the direction of the reactant flow. When the test number is PD3, the three reaction beds are sequentially filled with catalyst C, catalyst C, and catalyst C along the direction of the reactant flow.

[0065] Comparative Example 2 This comparative example illustrates the preparation and grading of three catalysts by conventional methods, with metals arranged in ascending order of metal content. Manufacturing method of catalyst cat-21: Alumina support Z was impregnated with an equal volume of an impregnation solution containing Mo and Ni, dried at 120°C for 3 hours, and roasted at 500°C for 2 hours. The resulting catalyst was named cat-21. Manufacturing method of catalyst cat-22: Alumina support Z was impregnated with an equal volume of an impregnation solution containing Mo and Ni, dried at 20°C for 3 hours, and roasted at 500°C for 2 hours. The resulting catalyst was named cat-22. Manufacturing method of catalyst cat-23: Alumina support Z was impregnated with an equal volume of an impregnation solution containing Mo and Ni, dried at 120°C for 3 hours, and roasted at 500°C for 2 hours. The resulting catalyst was named cat-23.

[0066] The catalysts are graded according to the grading principle of gradually increasing metal content, and the properties, contents and packing forms of the catalysts used are shown in Table 3 below.

[0067] [Table 3]

[0068] Comparative Example 3 For the case where the Ni content is gradually increased, and the Mo content of the catalyst is kept almost constant, the catalyst is graded and the properties and packing form of the catalyst used are shown in Table 4. Manufacturing method of catalyst cat-31: Alumina support Z was impregnated with an equal volume of an impregnation solution containing Mo and Ni, dried at 120°C for 3 hours, and roasted at 550°C for 2 hours. The resulting catalyst was designated as cat-31. Manufacturing method of catalyst cat-32: Alumina support Z was impregnated with an equal volume of an impregnation solution containing Mo and Ni, dried at 120°C for 3 hours, and roasted at 550°C for 2 hours. The resulting catalyst was named cat-32. Manufacturing method of catalyst cat-33: Alumina support Z was impregnated with an equal volume of an impregnation solution containing Mo and Ni, dried at 120°C for 3 hours, and roasted at 550°C for 2 hours. The resulting catalyst was designated as cat-33.

[0069] [Table 4]

[0070] Application Examples This application example evaluates the performance of the grading system and grading method according to the above-mentioned examples and comparative examples. This performance evaluation experiment was carried out in a small hydrogenation device. The catalyst was pre-vulcanized before activity evaluation. The vulcanization conditions were straight-run aviation kerosene containing 3% by volume of dimethyl disulfide as the sulfurized oil, the vulcanization pressure was 14.5 MPa, and the total liquid hourly space velocity was 2 h -1The hydrogen / oil volume ratio is 1000:1, and the temperatures are maintained at 230°C and 370°C for 8 hours. The evaluation conditions were a total reaction pressure of 14.5 MPa and a total liquid hourly space velocity of 1 h -1 The hydrogen / oil volume ratio was 1000:1. The properties of the feedstock oil used in the performance evaluation experiments are shown in Table 5, and the activity evaluation results are shown in Table 6. In Table 6, the denitrification activity is calculated according to the following formula in accordance with a first-order reaction. Relative denitrification activity = ln (nitrogen content in product / nitrogen content in raw material) / ln (nitrogen content in PD1 product / nitrogen content in raw material) x 100%. The denitrification activity of Test PD1 in Comparative Example 1 was set to 100%.

[0071] [Table 5]

[0072] [Table 6]

[0073] As can be seen from the evaluation results of catalytic activity after 500 hours shown in Table 6, compared with the comparative example, the use of the hydrogenation catalyst grading system according to the present invention significantly improved the denitrification activity and also provided good aromatic hydrocarbon saturation, thereby providing high-quality materials for the hydrocracking segment.

Claims

1. A grading system for hydrogenation catalysts, comprising: M hydrogenation catalysts are packed sequentially along the material flow direction, where M is an integer of 2 or more; the R value of the Nth hydrogenation catalyst is equal to or greater than the R value of the (N-1)th hydrogenation catalyst, and at least one Nth hydrogenation catalyst has an R value greater than the R value of the (N-1)th hydrogenation catalyst, N being an integer of 2 or greater and M or less; The R value is the ratio of the molar content of the Group VIII metal element in the hydrogenation catalyst characterized by X-ray photoelectron spectroscopy spectrum to the weight content of the Group VIII metal element in terms of oxide in the hydrogenation catalyst characterized by X-ray fluorescence spectrum; each hydrogenation catalyst independently comprises a support, a Group VIB metal active component, and a Group VIII metal active component; A grading system for hydrogenation catalysts, characterized in that the Group VIB metal active component is Mo and the Group VIII metal active component is Ni.

2. 2. The grading system of claim 1, wherein M is an integer greater than or equal to 3.

3. A grading system as described in claim 2, wherein M is 3 to 7.

4. 2. The grading system of claim 1, wherein the R value of the Nth hydrogenation catalyst is 1% to 20% higher than the R value of the N-1th hydrogenation catalyst.

5. The grading system described in claim 4, wherein the R value of the Nth hydrogenation catalyst is 2% to 10% higher than the R value of the N-1th hydrogenation catalyst.

6. 2. The grading system according to claim 1, wherein the R value of the hydrogenation catalyst is 3 to 150%.

7. The grading system described in claim 6, wherein the R value of the hydrogenation catalyst is 10 to 50%.

8. The reduction temperature of the N-1th hydrogenation catalyst is equal to or higher than the reduction temperature of the Nth hydrogenation catalyst, and the reduction temperature of the hydrogenation catalyst is H ２ - The grading system according to claim 1, wherein the peak top temperature of the reduction peak characterized by TPR.

9. A grading system as described in claim 8, wherein the reduction temperature of the N-1th hydrogenation catalyst is 5 to 150°C higher than the reduction temperature of the Nth hydrogenation catalyst.

10. The grading system described in claim 9, wherein the reduction temperature of the first hydrogenation catalyst loaded is 350 to 550°C.

11. 2. The grading system according to claim 1, wherein the packing volume ratio of adjacent hydrogenation catalysts is 1:20 to 20:

1.

12. The grading system described in claim 1, wherein the content of the Group VIB metal active component in terms of oxide is 9 to 50 weight % and the content of the Group VIII metal active component in terms of oxide is 1 to 15 weight % based on the total weight of the hydrogenation catalyst.

13. The grading system of claim 1, wherein the carrier is at least one selected from alumina, silica, silica-alumina, magnesium oxide, zirconia, boron oxide, and titanium dioxide.

14. Use of the hydrogenation catalyst grading system according to any one of claims 1 to 13 in the hydrotreatment of oil products.

15. A method for hydrogenating a target for hydrotreatment, carried out using the grading system described in any one of claims 1 to 13.

16. The oil product to be hydrotreated is introduced into the grading system to carry out a hydrogenation reaction, The conditions for the hydrogenation reaction are a reaction pressure of 3 to 20 MPa and a total liquid hourly space velocity of 0.2 to 4 h －１ , reaction temperature 260 to 430 ° C.; The oil product to be hydrotreated is at least one selected from diesel, VGO, CGO, and DAO, 16. The hydrogenation process of claim 15, wherein the hydrogenation reaction comprises at least one of hydrodesulfurization, hydrodenitrification, hydrodeoxygenation, and hydrosaturation.

17. the reaction temperature of the Nth hydrogenation catalyst bed is equal to or greater than the reaction temperature of the first hydrogenation catalyst bed; the reaction temperature of the Nth hydrogenation catalyst bed is equal to or greater than the reaction temperature of the N-1th hydrogenation catalyst bed; 16. The hydrogenation process according to claim 15, wherein the reaction temperature of the last hydrogenation catalyst bed is 410°C or less.

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