A method for grading a heavy oil hydroprocessing catalyst

Abstract

The application discloses a method for grading heavy oil hydro-treating catalysts, which comprises sequentially loading a hydrogenation pre-treating agent, a hydrogenation transition agent and a hydrogenation refining agent from top to bottom in a reactor, and maintaining the gradually increased content of active metal along the flow direction; the number of layers of active phase metal platelets of the hydrogenation pre-treating agent after sulfuration is within the range of 1.0-2.0 layers, and the pore volume of the catalyst with a pore diameter of 120nm-320nm accounts for 10%-25% of the total pore volume; the number of layers of active phase metal platelets of the hydrogenation transition agent after sulfuration is within the range of 3.0-4.5 layers, and the pore volume of the catalyst with a pore diameter of 6nm-15nm accounts for 40%-65% of the total pore volume; the number of layers of active phase metal platelets of the hydrogenation refining agent after sulfuration is within the range of 1.0-2.0 layers, and the pore volume of the catalyst with a pore diameter of 6nm-13nm accounts for 40%-60% of the total pore volume. The method can improve the activity and stability of the catalyst in removing metal, sulfur and nitrogen, and ensure the small change of aromatic hydrocarbon content and the long service life of the catalyst.

Description

Technical Field

[0001] This invention relates to a method for grading a catalyst, and more particularly to a method for grading a catalyst for heavy oil hydrotreating. Background Technology

[0002] Heavy oils such as residue oil, catalytic cracking slurry oil, and coking wax oil have high contents of polycyclic aromatic hydrocarbons (PAHs) and gums, making them excellent raw materials for the production of high-end carbon materials with broad market prospects. However, they contain large amounts of heteroatom compounds such as sulfur and nitrogen, and the content of these impurities must be reduced to a certain range to produce high-end carbon materials with qualified physicochemical properties. Current research focuses primarily on hydrotreating, using selective desulfurization catalysts to remove sulfur and nitrogen from the feedstock while retaining as many aromatics as possible, thus converting them into high-quality carbon materials during carbonization. However, there are few reports on extending the operating time of heavy oil hydrotreating units and improving catalyst lifespan. During the hydrotreating process, the stability of the heavy oil system itself is crucial; instability hinders the improvement of conversion rates during hydrotreating. Increasing the mass fraction of gums and aromatics is beneficial to improving the colloidal stability of heavy oil. If, during the reaction, large molecules such as gums and heavy aromatics decompose too quickly, or if the initial decomposition products fail to diffuse away from the catalyst surface in time, it will lead to excessive conversion of heavy oil macromolecules, a rapid decrease in aromatic content, a sudden deterioration in the colloidal stability of heavy oil, and a large amount of heavy components precipitating onto the catalyst, causing rapid coking and deactivation. This results in decreased catalyst activity and stability, reduced service life, shortened catalyst operating cycle, and increased hydrotreating costs. Existing catalyst gradation systems are insufficient to maintain high catalyst activity and stability while simultaneously removing sulfur, nitrogen, and other impurities from heavy oils such as residue oil, catalytic cracking slurry oil, and coking wax oil during hydrotreating.

[0003] Chinese patent CN103013567B discloses a method for producing needle coke feedstock from catalytic cracking slurry oil. The method includes a protected zone and a hydrotreating reaction zone. The protected zone is filled with an adsorbent capable of adsorbing catalytic cracking catalyst powder. The hydrotreating reaction zone is filled sequentially with a hydrotreating protective agent, a hydrodemetallizing agent, and a hydrodesulfurizing agent according to the flow direction of the reaction stream. In this patent's hydrotreating catalyst gradation, the hydrodesulfurizing agent at the final stage has a high number of metal flake crystal layers and high intrinsic hydrotreating activity, which easily leads to vigorous reactions, rapid catalyst deactivation, and affects the catalyst's service life.

[0004] Chinese Patent CN 114984970 A discloses a gradation method and application of a hydrodesulfurization catalyst for a solidification catalytic slurry. The gradation method includes: when the sulfur content of the solidification catalytic slurry is ≥0.8% and the content of tricyclic and tetracyclic aromatics is ≥55%, the reactor is sequentially loaded from top to bottom with a selective aromatics removal catalyst, a direct desulfurization catalyst, and a hydrodesulfurization catalyst; when the sulfur content of the solidification catalytic slurry is 0.35–0.8% and the content of tricyclic and tetracyclic aromatics is 40–55%, the reactor is sequentially loaded from top to bottom with a direct desulfurization catalyst and a hydrodesulfurization catalyst. This gradation method achieves efficient desulfurization while retaining as many tricyclic and tetracyclic aromatics as possible in the solidification catalytic slurry. The selective dearomatization catalyst used in the hydrogenation catalyst gradation method of this patent has too small a pore size. After shallow polycyclic aromatic hydrocarbon saturation ring opening, the active pores are quickly blocked, which seriously affects the activity of the metal inside the pores. This easily leads to excessive coking of the catalyst in the early stage, rapid deactivation, and consequently affects the operation cycle of the hydrogenation unit.

[0005] Chinese patent CN 111073689 A discloses a method for hydrotreating heavy oil, comprising the following steps: heavy oil feedstock enters a hydrotreating reactor and contacts a hydrotreating catalyst bed for a hydrotreating reaction; the reaction products flow out of the reactor; wherein the hydrotreating catalyst bed is graded and packed with at least two stages of sulfide-state hydrotreating catalyst along the feed direction, and in each stage of the sulfide-state hydrotreating catalyst, the average length of the metal active phase lamellar crystals increases progressively, the average number of lamellar layers decreases progressively, the content of active components increases progressively, and the probable pore size decreases progressively. This invention utilizes a specific catalyst gradation to effectively utilize the catalyst active centers, improve the coupling reaction performance between the active center structure and the reactant molecular structure, and significantly improve the stability of the entire system's hydrotreating reaction, such as demetallization, desulfurization, and denitrification. The hydrogenation catalyst gradation method described in this patent has several drawbacks. Due to the high number of lamellar layers at the front end of the catalyst, the intrinsic hydrogenation activity is high. However, the simultaneous deep hydrogenation and desulfurization of heavy oil leads to a sudden decrease in the instantaneous stability of the hydrogenated heavy oil, rapid catalyst coking, and a shortened operating cycle of the hydrogenation unit. Furthermore, the aromatic content in the hydrogenated product cannot be guaranteed. In addition, the catalyst in this technology uses an average number of lamellar layers within a certain range, which cannot guarantee that the number of each lamellar layer of the catalyst is within this range. This includes excessively large or small numbers of lamellar layers, which can easily cause problems such as severe catalyst carbon buildup and rapid deactivation.

[0006] Chinese patent CN 111196934 B discloses a method for grading catalysts for heavy oil hydrotreating. The reactor is sequentially loaded from top to bottom with a hydrodemetallization catalyst, a hydrodesulfurization catalyst, and a hydrodenitrogenation catalyst. The feed stream flows from top to bottom, maintaining the flow direction along the feed direction. The catalyst activity gradually increases, the pore size gradually decreases, the particle size gradually decreases, and the porosity gradually decreases. Each of the hydrodemetallization, hydrodesulfurization, and hydrodenitrogenation catalysts is independently composed of one or more catalysts. The active metal MoS2 in the sulfidated hydrodemetallization, hydrodesulfurization, and hydrodenitrogenation catalysts is highly dispersed. In the sulfidated hydrodemetallization catalyst, MoS2 is mainly dispersed in single and double layers, while in the sulfidated hydrodesulfurization catalyst, MoS2 is mainly dispersed in double layers. The catalyst gradation combination obtained by this method exhibits high activity and stability in demetallization, residual carbon removal, desulfurization, and denitrogenation, and has a long service life. The hydrogenation catalyst gradation method of this patent involves simultaneous deep hydrodesulfurization and aromatic removal of heavy oil, but it cannot selectively remove sulfur. The aromatic content in the hydrogenated product is greatly reduced, making it unsuitable for direct use as a raw material for the production of carbon materials.

[0007] Chinese Patent CN 105623717 A discloses a method for grading hydrogenation catalysts. This method includes sequentially loading a hydrogenation protection catalyst, a hydrogenation demetallization catalyst, a hydrogenation desulfurization catalyst, a hydrogenation denitrogenation catalyst, and / or a hydrogenation decarbonization catalyst along the flow direction. Each of the hydrogenation demetallization catalyst, hydrogenation desulfurization catalyst, hydrogenation denitrogenation catalyst, and hydrogenation decarbonization catalyst contains at least a portion of a bimodal porous catalyst. Furthermore, along the flow direction, in each of the bimodal porous catalysts, the most probable pore sizes of the small pore peaks and large pore peaks gradually decrease, the proportion of the pore volume of the small pore peaks to the total pore volume gradually increases, and the proportion of the pore volume of the large pore peaks to the total pore volume gradually decreases. This invention also discloses a method for heavy oil hydrogenation using the above-mentioned hydrogenation catalyst grading method. The method disclosed in this invention can improve the impurity removal rate and extend the operating cycle of the heavy oil hydrogenation unit. The hydrogenation catalyst gradation method of this patent, the combination of catalyst channel structure and active phase crystal layer number, enables simultaneous deep hydrogenation desulfurization and aromatic removal of heavy oil. However, it cannot selectively desulfurize, and the effects of desulfurization and removal of residual carbon and nitrogen are also generally poor. The aromatic content in the hydrogenated product is greatly reduced, making it unsuitable for direct use as a raw material for the production of carbon materials. Summary of the Invention

[0008] The purpose of this invention is to provide a gradation method for heavy oil hydrotreating catalysts. This method effectively utilizes the role of various catalysts, protects the stability of the heavy oil system during hydrotreating to a greater extent, improves the demetallization, desulfurization, and denitrification activity and stability of the catalyst, and ensures small changes in aromatic content, high aromatic retention rate, and long catalyst life.

[0009] To achieve the above objectives, the present invention provides a method for grading a catalyst for heavy oil hydrotreating. The method includes: sequentially loading a hydrotreating pretreatment agent, a hydrotreating transition agent, and a hydrorefining agent into a reactor from top to bottom, with the feedstock flowing from top to bottom, maintaining a gradual increase in the content of active metals in the catalyst along the flow direction.

[0010] The hydrogenation pretreatment agent, after sulfidation, has active phase metal flakes with a layer count all within the range of 1.0 to 2.0 layers. The catalyst pore volume with a diameter of 120 nm to 320 nm accounts for 10% to 25% of the total pore volume. If the proportion of pores with a diameter of 120 nm to 320 nm is too low, it will affect macromolecular diffusion; if the proportion is too high, it will affect the effective reaction activity specific surface area. Since the number of active phase metal flakes after sulfidation is all within the range of 1.0 to 2.0 layers, if the number of active phase metal flakes after sulfidation is higher than 2.0 layers, it is easy to experience high initial reaction activity, a sudden deterioration in the stability of heavy oil colloids, and a large amount of heavy components precipitating onto the catalyst, resulting in rapid coking and deactivation, and poor catalyst activity stability.

[0011] The hydrogenation transition agent, after sulfidation, has active phase metal lamellar crystals with a layer count all within the range of 3.0 to 4.5 layers. The catalyst pores with a diameter of 6 nm to 15 nm account for 40% to 65% of the total pore volume. If the proportion of pores with a diameter of 6 nm to 15 nm is too low, the effective active reaction space will be affected; if the proportion is too high, over-reaction of intermediate products will occur, leading to increased coking and a significant decrease in aromatic content. Furthermore, if the number of lamellar crystals is less than 3.0 layers, the desulfurization activity will decrease; if the number of lamellar crystals is higher than 4.5 layers, aromatic oversaturation will occur, resulting in a decrease in aromatic content.

[0012] In the aforementioned hydrorefining agent, the number of layers of the active phase metal lamellar crystals after sulfidation is entirely within the range of 1.0 to 2.0 layers, and the pore volume of the catalyst with a diameter of 6 nm to 13 nm accounts for 40% to 60% of the total pore volume. If the proportion of pore volume with a diameter of 6 nm to 13 nm is too low, it will affect the reaction space of sulfur and nitrogen-containing molecules, reducing the desulfurization and denitrification activity. If the proportion of pore volume with a diameter of 6 nm to 13 nm is too high, there will be problems with the deep removal of aromatics and a significant decrease in their content. The number of layers of the active phase metal lamellar crystals after sulfidation of the hydrorefining agent is entirely within the range of 1.0 to 2.0 layers. If the number of lamellar crystal layers is higher than 2.0 layers, there will be a disadvantage of increased aromatic condensation and coking.

[0013] The method for grading the heavy oil hydrotreating catalyst according to the present invention, wherein, by weight percentage, the hydrotreating pretreatment agent accounts for 10% to 30%, the hydrotreating transition agent accounts for 20% to 45%, and the hydrorefining agent accounts for 40% to 70%.

[0014] The method for grading heavy oil hydrotreating catalysts according to the present invention, wherein the sulfidation process of the hydrotreating pretreatment agent, the hydrotreating transition agent and the hydrorefining agent is not particularly limited, and they can be selected independently from dry sulfidation or wet sulfidation.

[0015] The method for grading the heavy oil hydrotreating catalyst according to the present invention, wherein the sulfiding agent in the sulfidation process of the hydrotreating pretreatment agent, the hydrotreating transition agent, and the hydrorefining agent is independently selected from at least one of H2S, thiols, disulfides, polysulfides, and thiophene carboxylic acid compounds; preferably, it is further independently selected from at least one of H2S, carbon disulfide, dimethyl sulfide, and dimethyl disulfide.

[0016] The method for grading the heavy oil hydrotreating catalyst according to the present invention preferably includes a hydrotreating pretreatment agent with an inorganic oxide as a support and a Group VIB metal and / or a Group VIII metal as an active component. Based on the weight of the catalyst, the active metals, calculated as oxides, are 3 wt% to 26 wt% for Group VIB metals, preferably 4.0 wt% to 8.0 wt%, and 0.5 wt% to 8 wt% for Group VIII metals, preferably 0.8 wt% to 2.2 wt%.

[0017] The method for grading the heavy oil hydrotreating catalyst according to the present invention preferably further includes an auxiliary agent selected from at least one of P, Si, F, and B.

[0018] The method for grading the heavy oil hydrotreating catalyst according to the present invention preferably includes a hydrotreating transition agent with an inorganic oxide as a support and a Group VIB metal and / or a Group VIII metal as an active component. Based on the weight of the catalyst, the active metals, calculated as oxides, are: Group VIB metals 3 wt% to 26 wt%, preferably 9.0 wt% to 15.0 wt%, and Group VIII metals 0.5 wt% to 8 wt%, preferably 2.3 wt% to 4.5 wt%.

[0019] The method for grading the heavy oil hydrotreating catalyst according to the present invention, wherein the hydrotreating transition agent preferably further includes an auxiliary agent selected from at least one of P, Si, F, and B.

[0020] The method for grading the heavy oil hydrotreating catalyst according to the present invention preferably includes a hydrorefining agent with an inorganic oxide as a support and a Group VIB metal and / or a Group VIII metal as an active component. Based on the weight of the catalyst, the active metals, calculated as oxides, are: Group VIB metals 3 wt% to 26 wt%, preferably 16.0 wt% to 22.0 wt%, and Group VIII metals 0.5 wt% to 8 wt%, preferably 3.0 wt% to 6.0 wt%.

[0021] The method for grading the heavy oil hydrotreating catalyst according to the present invention preferably further includes an auxiliary agent selected from at least one of P, Si, F, and B.

[0022] The method for grading the heavy oil hydrotreating catalyst according to the present invention preferably includes the following: the inorganic oxide is selected from at least one of alumina and silicon oxide; the group VIB metal is selected from at least one of W and Mo; and the group VIII metal is selected from at least one of Co and Ni.

[0023] The method for grading the catalyst for heavy oil hydrotreating according to the present invention preferably includes the following conditions: hydrogen pressure 3.0 MPa to 18.0 MPa, temperature 280°C to 420°C, and liquid hourly space velocity 0.15 h⁻¹. -1 ~3.5h -1 The hydrogen-to-oil volume ratio is 300–2000.

[0024] The method for grading the catalyst for heavy oil hydrotreating according to the present invention further preferably includes the following conditions: hydrogen pressure of 5.0 MPa to 16.0 MPa, temperature of 300°C to 390°C, and liquid hourly space velocity of 0.2 h⁻¹. -1 ~2.5h -1 The hydrogen-to-oil volume ratio is 400–1800.

[0025] The method for grading the heavy oil hydrotreating catalyst according to the present invention does not particularly limit the sources of the hydrotreating pretreatment agent, hydrotreating transition agent, and hydrorefining agent. They can be prepared using conventional commercial catalysts or conventional methods of the prior art. For example, the catalyst preparation method is as follows: the alumina support is saturated with a solution containing an active metal component to obtain a catalyst precursor, which is then dried and calcined to obtain the desired oxidized hydrotreating catalyst. The drying temperature is 90℃~260℃, preferably 100℃~200℃, and the drying time is 1h~7h, preferably 3h~5h; the calcination temperature is 400℃~600℃, preferably 450℃~560℃, and the calcination time is 1h~7h, preferably 3h~5h.

[0026] The gradation method of the present invention can be used in conventional fixed-bed hydrotreating units. In the actual use of the gradation method of the present invention, after the heavy oil feedstock and hydrogen are mixed, they enter the hydrotreating unit and pass through the supporting protective agent, hydrotreating pretreatment agent, hydrotreating transition agent and hydrotreating refining agent in sequence. The reacted oil and gas enter the subsequent separation unit for separation.

[0027] This invention discovers a method for grading heavy oil hydrotreating catalysts that can effectively and selectively desulfurize and delay coking. The catalyst gradation combination of this invention fully utilizes the physicochemical characteristics of several catalysts, exhibiting good activity and stability in removing sulfur, nitrogen, and other impurities, high aromatic hydrocarbon retention, and slowing down catalyst deactivation, thus extending the catalyst's operating cycle. It demonstrates beneficial effects that some existing catalyst gradations cannot achieve. The hydrotreating pretreatment agent has low intrinsic activity, contains a small number of large pores, and has few metal active sites, thus improving heavy oil stability and shallow conversion, and preventing rapid coking and deactivation. The hydrotreating transition agent has a large number of active metal lamellar layers, high intrinsic hydrodesulfurization activity, and a suitable pore distribution, reducing steric hindrance effects. This allows sulfur-containing macromolecules with significant steric hindrance to undergo ring opening or chain breakage, while having fewer active sites for aromatic hydrocarbon hydrosaturation. Reaction products diffuse away from the catalyst surface in a timely manner, avoiding deep reactions. The hydrorefining agent has fewer active metal lamellar layers, more metal active sites, and a suitable pore size distribution, primarily using direct hydrodesulfurization to achieve selective deep desulfurization.

[0028] Existing catalysts employ an average number of lamellar layers within a certain range, but this includes excessively large or small lamellar layer counts, easily leading to severe catalyst carbon buildup and rapid deactivation. After discovering this problem during their research, the inventors innovatively adopted a method where the number of active phase metal lamellar layers after sulfidation with the hydrogenation pretreatment agent is entirely within the range of 1.0–2.0 layers; the number of active phase metal lamellar layers after sulfidation with the hydrogenation transition agent is entirely within the range of 3.0–4.5 layers; and the number of active phase metal lamellar layers after sulfidation with the hydrogenation refining agent is entirely within the range of 1.0–2.0 layers. This solves the technical problems of severe catalyst carbon buildup and rapid deactivation in existing technologies.

[0029] Large molecules such as gums and heavy aromatics in heavy oil are slowly decomposed by a pretreatment agent containing large, unobstructed pores and low intrinsic activity. The products of the initial decomposition quickly leave the catalyst surface and then pass through a transition agent with a relatively large number of active metal crystal layers, high intrinsic activity for hydrodesulfurization, suitable pore distribution, and a moderate number of active sites. By reducing steric hindrance, this transition agent promotes ring-opening or chain breaking of sulfur-containing macromolecules, forming a moderate reaction. Finally, the product enters the refining agent treatment zone, which has a large number of metal active sites, a suitable pore distribution, and is mainly used for direct hydrodesulfurization. This process significantly reduces the content of impurities such as sulfur and nitrogen while effectively slowing down the condensation and coking of polycyclic aromatic hydrocarbons, achieving selective deep desulfurization, ensuring minimal changes in aromatic content, and maintaining high stability of the heavy oil system. This extends the catalyst's lifespan and reduces the operating cost of the hydrotreating unit. Attached Figure Description

[0030] Figure 1 This is a transmission electron microscope image of the hydrogenation pretreatment agent in Example 1 of the present invention.

[0031] Figure 2 This is a transmission electron microscope (TEM) image of the hydrogenation transition agent in Example 1 of the present invention.

[0032] Figure 3 This is a transmission electron microscope image of the hydrogenated refining preparation of Example 1 of the present invention. Detailed Implementation

[0033] The method of the present invention will be described in detail below with reference to specific embodiments, but this does not limit the scope of protection of the present invention. wt% is the mass fraction.

[0034] Analysis method:

[0035] The number of lamellar layers of the sulfide catalyst was statistically analyzed using transmission electron microscopy (TEM) (the average value was calculated manually from 30 TEM images); JEOL 2100PLus high-resolution TEM, magnification 250K, accelerating voltage 200kV, LaB filament, line resolution 0.14nm, point resolution 0.23nm.

[0036] The pore volume and pore size distribution of the catalyst were measured using a cryogenic liquid nitrogen adsorption method, employing a Micrometeritics ASAP 2010 automated adsorption system (USA). The pore size distribution of the catalyst was measured using the BJH method.

[0037] Example 1

[0038] Preparation of the hydrotreating pretreatment agent: The support was saturated with a solution containing MoO3 and NiO active components to obtain a catalyst precursor. This precursor was dried at 120℃ for 5 h, then heated to 500℃ at a rate of 5℃ / min and calcined at that temperature for 4 h to obtain the hydrotreating pretreatment agent. The catalyst contained 4.1 wt% MoO3 and 3.1 wt% NiO, with pores ranging from 120 nm to 320 nm in diameter accounting for 15% of the total pore volume.

[0039] Preparation of the hydrogenation transition agent: The support was saturated with a solution containing MoO3, NiO active components, and phosphoric acid to obtain a catalyst precursor. This precursor was dried at 110℃ for 6 h, then heated to 480℃ at a rate of 5℃ / min and calcined at that temperature for 5 h to obtain the hydrogenation transition agent. This catalyst contained 13.1 wt% MoO3, 1.2 wt% NiO, and 4.5 wt% P2O5, with pores ranging from 6 nm to 15 nm in diameter accounting for 50% of the total pore volume.

[0040] Preparation of the hydrorefining agent: The support was saturated with a solution containing MoO3, CoO active components, and ammonium phosphate to obtain a catalyst precursor. This precursor was dried at 150°C for 5 h, then heated to 550°C at a rate of 5°C / min and calcined at this temperature for 4 h to obtain the hydrorefining agent. The catalyst contained 20.5 wt% MoO3, 5 wt% CoO, and 0.8 wt% P2O5, with pores ranging from 6 nm to 13 nm in diameter accounting for 42% of the total pore volume.

[0041] Then, wet vulcanization was adopted, using CS2 as the vulcanizing agent at an addition amount of 2.0 wt%, and conventional four-line diesel oil as the vulcanizing oil. Hydrogen was passed through once, and the vulcanization conditions were constant temperature at 280℃ for 20 hours and constant temperature at 320℃ for 8 hours, with a heating rate of 10℃ / h.

[0042] The active metal MoS2 flakes in the hydrogenation pretreatment agent after sulfidation are all 1.0 to 2.0 layers; the active metal MoS2 flakes in the hydrogenation transition agent after sulfidation are all 3.0 to 4.5 layers; and the active metal MoS2 flakes in the hydrogenation refining agent after sulfidation are all 1.0 to 2.0 layers.

[0043] The hydrogenation pretreatment agent, hydrogenation transition agent, and hydrogenation refining agent are sequentially loaded into the bed of the reactor from top to bottom, with the mass ratios of 15%, 20%, and 65%, respectively.

[0044] Example 2

[0045] Preparation of hydrogenation pretreatment agent: Same as in Example 1.

[0046] Preparation of hydrogenation transition agent: Same as in Example 1.

[0047] Preparation of hydrogenated concentrate: Same as in Example 1.

[0048] Then, wet vulcanization was adopted, using CS2 as the vulcanizing agent at an addition amount of 2.0 wt%, and ordinary four-line diesel oil as the vulcanizing oil. Hydrogen was passed through once, and the vulcanization conditions were constant temperature at 280℃ for 20 hours and constant temperature at 320℃ for 8 hours, with a heating rate of 10℃ / h.

[0049] The active metal MoS2 flakes in the hydrogenation pretreatment agent after sulfidation are all 1.0 to 2.0 layers; the active metal MoS2 flakes in the hydrogenation transition agent after sulfidation are all 3.0 to 4.5 layers; and the active metal MoS2 flakes in the hydrogenation refining agent after sulfidation are all 1.0 to 2.0 layers.

[0050] The hydrogenation pretreatment agent, hydrogenation transition agent, and hydrogenation refining agent are sequentially loaded into the bed of the reactor from top to bottom, with the mass ratios of 25%, 30%, and 45%, respectively.

[0051] Example 3

[0052] Preparation of the hydrogenation pretreatment agent: A silicon-containing support was saturated with a solution containing MoO3 and NiO active components to obtain a catalyst precursor. This precursor was dried at 120℃ for 5 h, then heated to 500℃ at a rate of 5℃ / min and calcined at that temperature for 4 h to obtain the hydrogenation pretreatment agent. The catalyst contained 7.5 wt% MoO3, 2.0 wt% NiO, and 0.5 wt% SiO2, with pores ranging from 120 nm to 320 nm in diameter accounting for 11% of the total pore volume.

[0053] Preparation of the hydrogenation transition agent: The support was saturated with a solution containing MoO3, NiO active components, and phosphoric acid to obtain a catalyst precursor. This precursor was dried at 120℃ for 5 h, then heated to 500℃ at a rate of 5℃ / min and calcined at that temperature for 4 h to obtain the hydrogenation transition agent. This catalyst contained 10.0 wt% MoO3, 2.5 wt% NiO, and 3.5 wt% P2O5, with pores ranging from 6 nm to 15 nm in diameter accounting for 58% of the total pore volume.

[0054] Preparation of the hydrorefining agent: The support was saturated with a solution containing MoO3 and CoO active components to obtain a catalyst precursor. This precursor was dried at 120℃ for 5 h, then heated to 500℃ at a rate of 5℃ / min and calcined at that temperature for 4 h to obtain the hydrorefining agent. The catalyst contained 17.0 wt% MoO3 and 4.1 wt% CoO, with pores ranging from 6 nm to 13 nm in diameter accounting for 52% of the total pore volume.

[0055] Then, wet vulcanization was adopted, using CS2 as the vulcanizing agent at an addition amount of 2.0 wt%, and conventional four-line diesel oil as the vulcanizing oil. Hydrogen was passed through once, and the vulcanization conditions were constant temperature at 280℃ for 20 hours and constant temperature at 320℃ for 8 hours, with a heating rate of 10℃ / h.

[0056] The active metal MoS2 flakes in the hydrogenation pretreatment agent after sulfidation are all 1.0 to 2.0 layers; the active metal MoS2 flakes in the hydrogenation transition agent after sulfidation are all 3.0 to 4.5 layers; and the active metal MoS2 flakes in the hydrogenation refining agent after sulfidation are all 1.0 to 2.0 layers.

[0057] The hydrogenation pretreatment agent, hydrogenation transition agent, and hydrogenation refining agent are sequentially loaded into the bed of the reactor from top to bottom, with the mass ratios of 10%, 35%, and 55%, respectively.

[0058] Example 4

[0059] Preparation of the hydrotreating pretreatment agent: The support was saturated with a solution containing MoO3, NiO active components, and ammonium phosphate to obtain a catalyst precursor. This precursor was dried at 120℃ for 5 h, then heated to 500℃ at a rate of 5℃ / min and calcined at that temperature for 4 h to obtain the hydrotreating pretreatment agent. The catalyst contained 3.7 wt% MoO3, 0.8 wt% NiO, and 0.3 wt% P2O5, with pores ranging from 120 nm to 320 nm in diameter accounting for 23% of the total pore volume.

[0060] Preparation of the hydrogenation transition agent: The support was saturated with a solution containing MoO3, NiO active components, and phosphoric acid to obtain a catalyst precursor. This precursor was dried at 110℃ for 6 h, then heated to 480℃ at a rate of 5℃ / min and calcined at that temperature for 5 h to obtain the hydrogenation transition agent. The catalyst contained 9.7 wt% MoO3 and 2.1 wt% NiO, and the pore volume with a diameter of 6 nm to 15 nm accounted for 62% of the total pore volume.

[0061] Preparation of the hydrorefining agent: The support was saturated with a solution containing MoO3, CoO active components, and ammonium phosphate to obtain a catalyst precursor. This precursor was dried at 150°C for 5 h, then heated to 550°C at a rate of 5°C / min and calcined at this temperature for 4 h to obtain the hydrorefining agent. The catalyst contained 12.6 wt% MoO3, 3.1 wt% CoO, and 3.8 wt% P2O5, with pores ranging from 6 nm to 13 nm in diameter accounting for 60% of the total pore volume.

[0062] Then, wet vulcanization was adopted, using CS2 as the vulcanizing agent at an addition amount of 2.0 wt%, and conventional four-line diesel oil as the vulcanizing oil. Hydrogen was passed through once, and the vulcanization conditions were constant temperature at 280℃ for 20 hours and constant temperature at 320℃ for 8 hours, with a heating rate of 10℃ / h.

[0063] The active metal MoS2 flakes in the hydrogenation pretreatment agent after sulfidation are all 1.0 to 2.0 layers; the active metal MoS2 flakes in the hydrogenation transition agent after sulfidation are all 3.0 to 4.5 layers; and the active metal MoS2 flakes in the hydrogenation refining agent after sulfidation are all 1.0 to 2.0 layers.

[0064] The hydrogenation pretreatment agent, hydrogenation transition agent, and hydrogenation refining agent are sequentially loaded into the bed of the reactor from top to bottom, with the mass ratios of 25%, 30%, and 45%, respectively.

[0065] Example 5

[0066] Preparation of the hydrotreating pretreatment agent: The support was saturated with a solution containing MoO3 and NiO active components to obtain a catalyst precursor. This precursor was dried at 120℃ for 5 h, then heated to 480℃ at a rate of 5℃ / min and calcined at that temperature for 4 h to obtain the hydrotreating pretreatment agent. The catalyst contained 8.0 wt% MoO3 and 2.0 wt% NiO, with pores ranging from 120 nm to 320 nm in diameter accounting for 18% of the total pore volume.

[0067] Preparation of the hydrogenation transition agent: The support was saturated with a solution containing MoO3, NiO active components, and phosphoric acid to obtain a catalyst precursor. This precursor was dried at 110℃ for 6 h, then heated to 480℃ at a rate of 5℃ / min and calcined at that temperature for 5 h to obtain the hydrogenation transition agent. The catalyst contained 13.6 wt% MoO3, 4.5 wt% NiO, and 3.5 wt% P2O5, with pores ranging from 6 nm to 15 nm in diameter accounting for 42% of the total pore volume.

[0068] Preparation of the hydrorefining agent: The support was saturated with a solution containing MoO3, CoO active components, and ammonium phosphate to obtain a catalyst precursor. This precursor was dried at 150°C for 5 h, then heated to 550°C at a rate of 5°C / min and calcined at this temperature for 4 h to obtain the hydrorefining agent. The catalyst contained 21.2 wt% MoO3, 3.5 wt% CoO, and 5.8 wt% P2O5, with pores ranging from 6 nm to 13 nm in diameter accounting for 55% of the total pore volume.

[0069] Then, wet vulcanization was adopted, using CS2 as the vulcanizing agent at an addition amount of 2.0 wt%, and conventional four-line diesel oil as the vulcanizing oil. Hydrogen was passed through once, and the vulcanization conditions were constant temperature at 280℃ for 20 hours and constant temperature at 320℃ for 8 hours, with a heating rate of 10℃ / h.

[0070] The active metal MoS2 flakes in the hydrogenation pretreatment agent after sulfidation are all 1.0 to 2.0 layers; the active metal MoS2 flakes in the hydrogenation transition agent after sulfidation are all 3.0 to 4.5 layers; and the active metal MoS2 flakes in the hydrogenation refining agent after sulfidation are all 1.0 to 2.0 layers.

[0071] The hydrogenation pretreatment agent, hydrogenation transition agent, and hydrogenation refining agent are sequentially loaded into the bed of the reactor from top to bottom, with the mass ratios of 15%, 20%, and 65%, respectively.

[0072] Example 6

[0073] Preparation of the hydrotreating pretreatment agent: The support was saturated with a solution containing MoO3 and NiO active components to obtain a catalyst precursor. This precursor was dried at 120℃ for 5 h, then heated to 500℃ at a rate of 5℃ / min and calcined at that temperature for 4 h to obtain the hydrotreating pretreatment agent. The catalyst contained 12.0 wt% MoO3 and 2.1 wt% NiO, with pores ranging from 120 nm to 320 nm in diameter accounting for 20% of the total pore volume.

[0074] Preparation of the hydrogenation transition agent: The support was saturated with a solution containing MoO3, NiO active components, and phosphoric acid to obtain a catalyst precursor. This precursor was dried at 110℃ for 6 h, then heated to 480℃ at a rate of 5℃ / min and calcined at that temperature for 5 h to obtain the hydrogenation transition agent. The catalyst contained 18.0 wt% MoO3, 3.3 wt% NiO, and 5.5 wt% P2O5, with pores ranging from 6 nm to 15 nm in diameter accounting for 47% of the total pore volume.

[0075] Preparation of the hydrorefining agent: The support was saturated with a solution containing MoO3, CoO active components, and ammonium phosphate to obtain a catalyst precursor. This precursor was dried at 150°C for 5 h, then heated to 550°C at a rate of 5°C / min and calcined at this temperature for 4 h to obtain the hydrorefining agent. The catalyst contained 21.0 wt% MoO3, 5.7 wt% CoO, and 3.8 wt% P2O5, with pores ranging from 6 nm to 13 nm in diameter accounting for 52% of the total pore volume.

[0076] Then, wet vulcanization was adopted, using CS2 as the vulcanizing agent at an addition amount of 2.0 wt%, and conventional four-line diesel oil as the vulcanizing oil. Hydrogen was passed through once, and the vulcanization conditions were constant temperature at 280℃ for 20 hours and constant temperature at 320℃ for 8 hours, with a heating rate of 10℃ / h.

[0077] The active metal MoS2 flakes in the hydrogenation pretreatment agent after sulfidation are all 1.0 to 2.0 layers; the active metal MoS2 flakes in the hydrogenation transition agent after sulfidation are all 3.0 to 4.5 layers; and the active metal MoS2 flakes in the hydrogenation refining agent after sulfidation are all 1.0 to 2.0 layers.

[0078] The hydrogenation pretreatment agent, hydrogenation transition agent, and hydrogenation refining agent are sequentially loaded into the bed of the reactor from top to bottom, with the mass ratios of 15%, 20%, and 65%, respectively.

[0079] Example 7

[0080] Preparation of the hydrotreating pretreatment agent: The support was saturated with a solution containing WO3 and CoO active components to obtain a catalyst precursor. This precursor was dried at 120℃ for 5 h, then heated to 500℃ at a rate of 5℃ / min and calcined at this temperature for 4 h to obtain the hydrotreating pretreatment agent. The catalyst contained 12.0 wt% WO3 and 2.1 wt% CoO, with pores ranging from 120 nm to 320 nm in diameter accounting for 20% of the total pore volume.

[0081] Preparation of the hydrogenation transition agent: A support containing B was saturated with a solution containing WO3 and CoO active components to obtain a catalyst precursor. This precursor was dried at 110℃ for 6 h, then heated to 480℃ at a rate of 5℃ / min and calcined at that temperature for 5 h to obtain the hydrogenation transition agent. The catalyst contained 18.0 wt% WO3, 3.3 wt% CoO, and 1.5 wt% B2O3, with pores ranging from 6 nm to 15 nm in diameter accounting for 52% of the total pore volume.

[0082] Preparation of the hydrorefining agent: A Si-containing support was saturated with a solution containing WO3, NiO active components, and ammonium phosphate to obtain a catalyst precursor. This precursor was dried at 150°C for 5 hours, then heated to 550°C at a rate of 5°C / min and calcined at this temperature for 4 hours to obtain the hydrorefining agent. The catalyst contained 21.0 wt% WO3, 5.7 wt% NiO, and 0.8 wt% SiO2, with pores ranging from 6 nm to 13 nm in diameter accounting for 58% of the total pore volume.

[0083] Then, dry vulcanization was adopted, using DMDS as the vulcanizing agent. The pressure of the vulcanization process was 16 MPa, the circulating hydrogen volume was 300 L / h, and the vulcanization conditions were constant temperature at 230℃ for 10 h, constant temperature at 280℃ for 4 h, and constant temperature at 320℃ for 6 h, with a heating rate of 10℃ / h.

[0084] The active metal flakes of the hydrogenation pretreatment agent after sulfidation are all 1.0 to 2.0 layers thick; the active metal flakes of the hydrogenation transition agent after sulfidation are all 3.0 to 4.5 layers thick; and the active metal flakes of the hydrogenation refining agent after sulfidation are all 1.0 to 2.0 layers thick.

[0085] The hydrogenation pretreatment agent, hydrogenation transition agent, and hydrogenation refining agent are sequentially loaded into the bed of the reactor from top to bottom, with the mass ratios of 15%, 20%, and 65%, respectively.

[0086] Comparative Example 1

[0087] Referring to Example 1 of CN 111073689 A, the following catalyst gradation method was adopted.

[0088] Hydrogenation catalyst I: MoO3 content 12.0wt%, NiO content 2.1wt%, and pore volume with diameter of 120nm~320nm accounts for 5% of the total pore volume.

[0089] Hydrogenation catalyst II: MoO3 content 18.0wt%, NiO content 3.3wt%, and pore volume with a diameter of 6nm to 15nm accounts for 75% of the total pore volume.

[0090] Hydrogenation catalyst III: MoO3 content 21.0wt%, NiO content 5.7wt%, and pore volume with a diameter of 6nm to 13nm accounts for 85% of the total pore volume.

[0091] The vulcanization conditions were the same as those in Example 1 of CN 111073689 A.

[0092] The average number of active phase metal lamellar layers in the sulfidated hydrogenation catalyst I is 8.7, with 8.0 layers accounting for 60% of all lamellar layers, 9.0 layers accounting for 20%, 10.0 layers accounting for 10%, and 11.0 layers accounting for 10%. The average number of active phase metal lamellar layers in the sulfidated hydrogenation catalyst II is 5.7, with 4.0 layers accounting for 20%, 5.0 layers accounting for 50%, and 8.0 layers accounting for 30%. The average number of active phase metal lamellar layers in the sulfidated hydrogenation catalyst III is 2.4, with 1.0 layers accounting for 20%, 2.0 layers accounting for 50%, and 4 layers accounting for 30%.

[0093] Hydrogenation catalyst I, hydrogenation catalyst II, and hydrogenation catalyst III are loaded sequentially from top to bottom in the bed of the reactor, with the mass proportions of 20%, 30%, and 50%, respectively.

[0094] Comparative Example 2

[0095] Referring to Comparative Example 1 of CN 111073689 A, the following catalyst gradation method was adopted.

[0096] Hydrogenation catalyst I: MoO3 content 12.0wt%, NiO content 2.7wt%, and pore volume with diameter of 120nm~320nm accounts for 5% of the total pore volume.

[0097] Hydrogenation catalyst II: MoO3 content 18.7wt%, NiO content 4.6wt%, and pore volume with a diameter of 6nm to 15nm accounts for 75% of the total pore volume.

[0098] Hydrogenation catalyst III: MoO3 content 24.5wt%, NiO content 6.7wt%, and pore volume with diameter of 6nm to 13nm accounts for 72% of the total pore volume.

[0099] The vulcanization conditions are the same as those in CN 111073689 A. (Comparative Example 1)

[0100] The average number of active phase metal lamellar layers in the sulfidated hydrogenation catalyst I is 7.9, with 7.0 layers accounting for 40% of all lamellar layers, 8.0 layers accounting for 40%, 9.0 layers accounting for 10%, and 10.0 layers accounting for 10%. The average number of active phase metal lamellar layers in the sulfidated hydrogenation catalyst II is 8.8, with 7.0 layers accounting for 20%, 8.0 layers accounting for 40%, 10.0 layers accounting for 20%, and 11.0 layers accounting for 20%. The average number of active phase metal lamellar layers in the sulfidated hydrogenation catalyst III is 8.2, with 7.0 layers accounting for 20%, 8.0 layers accounting for 40%, and 9.0 layers accounting for 40%.

[0101] Hydrogenation catalyst I, hydrogenation catalyst II, and hydrogenation catalyst III are loaded sequentially from top to bottom in the reactor bed, with the mass proportions of 20%, 30%, and 50%, respectively.

[0102] Comparative Example 3

[0103] Referring to Comparative Example 2 of CN 111073689 A, the following catalyst gradation method was adopted.

[0104] Hydrogenation catalyst I: MoO3 content 11.2wt%, NiO content 2.9wt%, and pore volume with diameter of 120nm~320nm accounts for 6% of the total pore volume.

[0105] Hydrogenation catalyst II: MoO3 content 20.0wt%, NiO content 3.7wt%, and pore volume with a diameter of 6nm to 15nm accounts for 88% of the total pore volume.

[0106] Hydrogenation catalyst III: MoO3 content 24.8wt%, NiO content 5.7wt%, and pore volume with diameter of 6nm to 13nm accounts for 80% of the total pore volume.

[0107] Comparative Example 2: Vulcanization conditions are the same as those specified in CN 111073689 A.

[0108] The average number of active phase metal lamellar layers in the sulfidated hydrogenation catalyst I is 4.0, with lamellar layers 1.0 accounting for 10% of all lamellar layers, lamellar layers 2.0 accounting for 10% of all lamellar layers, lamellar layers 3.0 accounting for 10% of all lamellar layers, lamellar layers 4.0 accounting for 50% of all lamellar layers, lamellar layers 5.0 accounting for 10% of all lamellar layers, and lamellar layers 9.0 accounting for 10% of all lamellar layers. The average number of active phase metal lamellar layers in the sulfidated hydrogenation catalyst II is 4.5, with lamellar layers 2.0 accounting for 10% of all lamellar layers, lamellar layers 3.0 accounting for 10% of all lamellar layers, lamellar layers 4.0 accounting for 40% of all lamellar layers, and lamellar layers 6.0 accounting for 40% of all lamellar layers. The average number of active phase metal lamellar layers in the sulfidated hydrogenation catalyst III is 5.2, of which 3.0 lamellar layers account for 20% of all lamellar layers, 5.0 lamellar layers account for 40% of all lamellar layers, 6.0 lamellar layers account for 20% of all lamellar layers, and 7.0 lamellar layers account for 20% of all lamellar layers.

[0109] Hydrogenation catalyst I, hydrogenation catalyst II, and hydrogenation catalyst III are loaded sequentially from top to bottom in the reactor bed, with the mass proportions of 20%, 30%, and 50%, respectively.

[0110] Comparative Example 4

[0111] Referring to Comparative Example 3 of CN 111073689 A, the following catalyst gradation method was adopted.

[0112] Hydrogenation catalyst I: MoO3 content 11.5wt%, NiO content 2.8wt%, and pore volume with diameter of 120nm~320nm accounts for 9% of the total pore volume.

[0113] Hydrogenation catalyst II: MoO3 content 20.5wt%, NiO content 3.8wt%, and pore volume with a diameter of 6nm to 15nm accounts for 80% of the total pore volume.

[0114] Hydrogenation catalyst III: MoO3 content 25.8wt%, NiO content 5.5wt%, and pore volume with a diameter of 10nm to 15nm accounts for 92% of the total pore volume.

[0115] The vulcanization conditions are the same as those in CN 111073689 A. (Comparative Example 3)

[0116] The average number of active phase metal lamellar layers in the sulfidated hydrogenation catalyst I is 2.5, of which 1.0 lamellar layers account for 20% of all lamellar layers, 2.0 lamellar layers account for 40% of all lamellar layers, 3.0 lamellar layers account for 10% of all lamellar layers, and 4.0 lamellar layers account for 30% of all lamellar layers. The average number of active phase metal lamellar layers in the sulfidated hydrogenation catalyst II is 2.8, with 2.0 lamellar layers accounting for 50% of all lamellar layers, 3.0 lamellar layers accounting for 20% of all lamellar layers, and 4.0 lamellar layers accounting for 30% of all lamellar layers. The average number of active phase metal lamellar layers in the sulfidated hydrogenation catalyst III is 3.0, with 1.0 lamellar layers accounting for 20% of all lamellar layers, 2.0 lamellar layers accounting for 20% of all lamellar layers, 3.0 lamellar layers accounting for 20% of all lamellar layers, 4.0 lamellar layers accounting for 30% of all lamellar layers, and 6.0 lamellar layers accounting for 10% of all lamellar layers.

[0117] Hydrogenation catalyst I, hydrogenation catalyst II, and hydrogenation catalyst III are loaded sequentially from top to bottom in the reactor bed, with the mass proportions of 20%, 30%, and 50%, respectively.

[0118] Comparative Example 5

[0119] Referring to Example 2 of CN 105623717 A, the following catalyst gradation method was adopted.

[0120] Protective agents: MoO3 content 3.0wt%, NiO content 0.8wt%.

[0121] Metal removal agent: MoO3 content 8.4wt%, NiO content 1.5wt%, and pore volume with diameter of 120nm~320nm accounts for 8% of the total pore volume.

[0122] Desulfurizer: MoO3 content 16.2wt%, NiO content 4.5wt%, and pores with diameters of 6nm to 15nm account for 70% of the total pore volume.

[0123] Carbon removal agent: MoO3 content 18.0wt%, NiO content 5.0wt%, and pore volume with diameter of 6nm to 13nm accounts for 65% of the total pore volume.

[0124] The vulcanization conditions are the same as in Example 1.

[0125] After sulfidation, the active phase metal flakes of the demetallizing agent with 1.0 to 2.0 layers account for 86.5% of all flakes, with the remainder being flakes with 2 or more layers; after sulfidation, the active phase metal flakes of the desulfurizing agent with 1.0 to 2.0 layers account for 20% of all flakes, the flakes with 3.0 to 4.5 layers account for 20% of all flakes, the flakes with 2.0 to 3.0 layers account for 51% of all flakes, with the remainder being flakes with 4.5 or more layers; after sulfidation, the active phase metal flakes of the carbon removal agent with 1.0 to 2.0 layers account for 4% of all flakes, the flakes with 3.0 to 4.5 layers account for 60% of all flakes, with the remainder being flakes with 4.5 or more layers.

[0126] The protective agent, demetallizing agent, desulfurizing agent, and decarbonizing agent are sequentially packed in the bed of the reactor from top to bottom, with the mass ratios of 5%, 35%, 30%, and 30%, respectively.

[0127] Comparative Example 6

[0128] The difference from Example 1 is that the pore volume of the hydrogenation pretreatment agent with a diameter of 120 nm to 320 nm accounts for 5% of the total pore volume.

[0129] Preparation of the hydrotreating pretreatment agent: The support was saturated with a solution containing MoO3 and NiO active components to obtain a catalyst precursor. This precursor was dried at 120℃ for 5 h, then heated to 480℃ at a rate of 5℃ / min and calcined at that temperature for 4 h to obtain the hydrotreating pretreatment agent. The catalyst contained 4.1 wt% MoO3 and 3.1 wt% NiO, with a pore volume of 120 nm to 320 nm accounting for 5% of the total pore volume.

[0130] Preparation of the hydrogenation transition agent: The support was saturated with a solution containing MoO3, NiO active components, and phosphoric acid to obtain a catalyst precursor. This precursor was dried at 110℃ for 6 h, then heated to 480℃ at a rate of 5℃ / min and calcined at that temperature for 5 h to obtain the hydrogenation transition agent. This catalyst contained 13.1 wt% MoO3, 1.2 wt% NiO, and 4.5 wt% P2O5, with pores ranging from 6 nm to 15 nm in diameter accounting for 50% of the total pore volume.

[0131] Preparation of the hydrorefining agent: The support was saturated with a solution containing MoO3, CoO active components, and ammonium phosphate to obtain a catalyst precursor. This precursor was dried at 150°C for 5 h, then heated to 550°C at a rate of 5°C / min and calcined at this temperature for 4 h to obtain the hydrorefining agent. The catalyst contained 20.5 wt% MoO3, 5 wt% CoO, and 0.8 wt% P2O5, with pores ranging from 6 nm to 13 nm in diameter accounting for 42% of the total pore volume.

[0132] Then, wet vulcanization was adopted, using CS2 as the vulcanizing agent at an addition amount of 2.0 wt%, and conventional four-line diesel oil as the vulcanizing oil. Hydrogen was passed through once, and the vulcanization conditions were constant temperature at 280℃ for 20 hours and constant temperature at 320℃ for 8 hours, with a heating rate of 10℃ / h.

[0133] The active metal MoS2 flakes in the hydrogenation pretreatment agent after sulfidation are all 1.0 to 2.0 layers; the active metal MoS2 flakes in the hydrogenation transition agent after sulfidation are all 3.0 to 4.5 layers; and the active metal MoS2 flakes in the hydrogenation refining agent after sulfidation are all 1.0 to 2.0 layers.

[0134] The hydrogenation pretreatment agent, hydrogenation transition agent, and hydrogenation refining agent are sequentially loaded into the bed of the reactor from top to bottom, with the mass ratios of 15%, 20%, and 65%, respectively.

[0135] Comparative Example 7

[0136] The difference from Example 1 is that the hydrogenation transition agent has a pore volume of 6 nm to 15 nm in diameter, accounting for 70% of the total pore volume.

[0137] Preparation of the hydrotreating pretreatment agent: The support was saturated with a solution containing MoO3 and NiO active components to obtain a catalyst precursor. This precursor was dried at 120℃ for 5 h, then heated to 500℃ at a rate of 5℃ / min and calcined at that temperature for 4 h to obtain the hydrotreating pretreatment agent. The catalyst contained 4.1 wt% MoO3 and 3.1 wt% NiO, with pores ranging from 120 nm to 320 nm in diameter accounting for 15% of the total pore volume.

[0138] Preparation of the hydrogenation transition agent: The support was saturated with a solution containing MoO3, NiO active components, and phosphoric acid to obtain a catalyst precursor. This precursor was dried at 110℃ for 6 h, then heated to 450℃ at a rate of 5℃ / min and calcined at that temperature for 5 h to obtain the hydrogenation transition agent. This catalyst contained 13.1 wt% MoO3, 1.2 wt% NiO, and 4.5 wt% P2O5, with pores ranging from 6 nm to 15 nm in diameter accounting for 70% of the total pore volume.

[0139] Preparation of the hydrorefining agent: The support was saturated with a solution containing MoO3, CoO active components, and ammonium phosphate to obtain a catalyst precursor. This precursor was dried at 150°C for 5 h, then heated to 550°C at a rate of 5°C / min and calcined at this temperature for 4 h to obtain the hydrorefining agent. The catalyst contained 20.5 wt% MoO3, 5 wt% CoO, and 0.8 wt% P2O5, with pores ranging from 6 nm to 13 nm in diameter accounting for 42% of the total pore volume.

[0140] Then, wet vulcanization was adopted, using CS2 as the vulcanizing agent at an addition amount of 2.0 wt%, and conventional four-line diesel oil as the vulcanizing oil. Hydrogen was passed through once, and the vulcanization conditions were constant temperature at 280℃ for 20 hours and constant temperature at 320℃ for 8 hours, with a heating rate of 10℃ / h.

[0141] The active metal MoS2 flakes in the hydrogenation pretreatment agent after sulfidation are all 1.0 to 2.0 layers; the active metal MoS2 flakes in the hydrogenation transition agent after sulfidation are all 3.0 to 4.5 layers; and the active metal MoS2 flakes in the hydrogenation refining agent after sulfidation are all 1.0 to 2.0 layers.

[0142] The hydrogenation pretreatment agent, hydrogenation transition agent, and hydrogenation refining agent are sequentially loaded into the bed of the reactor from top to bottom, with the mass ratios of 15%, 20%, and 65%, respectively.

[0143] Comparative Example 8

[0144] The difference from Example 1 is that the hydrogenated refining agent has a pore volume of 6 nm to 13 nm in diameter, which accounts for 72% of the total pore volume.

[0145] Preparation of the hydrotreating pretreatment agent: The support was saturated with a solution containing MoO3 and NiO active components to obtain a catalyst precursor. This precursor was dried at 120℃ for 5 h, then heated to 500℃ at a rate of 5℃ / min and calcined at that temperature for 4 h to obtain the hydrotreating pretreatment agent. The catalyst contained 4.1 wt% MoO3 and 3.1 wt% NiO, with pores ranging from 120 nm to 320 nm in diameter accounting for 15% of the total pore volume.

[0146] Preparation of the hydrogenation transition agent: The support was saturated with a solution containing MoO3, NiO active components, and phosphoric acid to obtain a catalyst precursor. This precursor was dried at 110℃ for 8 h, then heated to 480℃ at a rate of 5℃ / min and calcined at that temperature for 5 h to obtain the hydrogenation transition agent. This catalyst contained 13.1 wt% MoO3, 1.2 wt% NiO, and 4.5 wt% P2O5, with pores ranging from 6 nm to 15 nm in diameter accounting for 50% of the total pore volume.

[0147] Preparation of the hydrorefining agent: The support was saturated with a solution containing MoO3, CoO active components, and ammonium phosphate to obtain a catalyst precursor. This precursor was dried at 150°C for 5 h, then heated to 500°C at a rate of 5°C / min and calcined at this temperature for 4 h to obtain the hydrorefining agent. The catalyst contained 20.5 wt% MoO3, 5 wt% CoO, and 0.8 wt% P2O5, with pores ranging from 6 nm to 13 nm in diameter accounting for 72% of the total pore volume.

[0148] Then, wet vulcanization was adopted, using CS2 as the vulcanizing agent at an addition amount of 2.0 wt%, and conventional four-line diesel oil as the vulcanizing oil. Hydrogen was passed through once, and the vulcanization conditions were constant temperature at 280℃ for 20 hours and constant temperature at 320℃ for 8 hours, with a heating rate of 10℃ / h.

[0149] The active metal MoS2 flakes in the hydrogenation pretreatment agent after sulfidation are all 1.0 to 2.0 layers; the active metal MoS2 flakes in the hydrogenation transition agent after sulfidation are all 3.0 to 4.5 layers; and the active metal MoS2 flakes in the hydrogenation refining agent after sulfidation are all 1.0 to 2.0 layers.

[0150] The hydrogenation pretreatment agent, hydrogenation transition agent, and hydrogenation refining agent are sequentially loaded into the bed of the reactor from top to bottom, with the mass ratios of 15%, 20%, and 65%, respectively.

[0151] Comparative Example 9

[0152] The difference from Example 1 is that the number of active metal MoS2 flakes after sulfurization with hydrogenated refining agent is only partially in the range of 1.0 to 2.0 layers, the number of active metal MoS2 flakes after sulfurization with hydrogenated transition agent is only partially in the range of 3.0 to 4.5 layers, and the number of active metal MoS2 flakes after sulfurization with hydrogenated refining agent is only partially in the range of 1.0 to 2.0 layers.

[0153] Preparation of the hydrotreating pretreatment agent: The support was saturated with a solution containing MoO3 and NiO active components to obtain a catalyst precursor. This precursor was dried at 120℃ for 5 h, then heated to 520℃ at a rate of 5℃ / min and calcined at that temperature for 5 h to obtain the hydrotreating pretreatment agent. The catalyst contained 4.1 wt% MoO3 and 3.1 wt% NiO, with pores ranging from 120 nm to 320 nm in diameter accounting for 15% of the total pore volume.

[0154] Preparation of the hydrogenation transition agent: The support was saturated with a solution containing MoO3, NiO active components, and phosphoric acid to obtain a catalyst precursor. This precursor was dried at 100℃ for 5 h, then heated to 490℃ at a rate of 5℃ / min and calcined at that temperature for 5 h to obtain the hydrogenation transition agent. This catalyst contained 13.1 wt% MoO3, 1.2 wt% NiO, and 4.5 wt% P2O5, with pores ranging from 6 nm to 15 nm in diameter accounting for 50% of the total pore volume.

[0155] Preparation of the hydrorefining agent: The support was saturated with a solution containing MoO3, CoO active components, and ammonium phosphate to obtain a catalyst precursor. This precursor was dried at 150°C for 5 h, then heated to 580°C at a rate of 5°C / min and calcined at that temperature for 5 h to obtain the hydrorefining agent. The catalyst contained 20.5 wt% MoO3, 5 wt% CoO, and 0.8 wt% P2O5, with pores ranging from 6 nm to 13 nm in diameter accounting for 42% of the total pore volume.

[0156] Then, wet vulcanization was adopted, using CS2 as the vulcanizing agent at an addition amount of 2.0 wt%, and conventional four-line diesel oil as the vulcanizing oil. Hydrogen was passed through once, and the vulcanization conditions were constant temperature at 280℃ for 20 hours and constant temperature at 320℃ for 8 hours, with a heating rate of 10℃ / h.

[0157] The average number of lamellae in the sulfidated hydrogenation pretreatment agent MoS2 is 1.0–2.0 layers, with 1.0 layers accounting for 50% of all lamellae, 2.0 layers accounting for 30%, 3.0 layers accounting for 10%, and 4.0 layers accounting for 10%. The average number of lamellae in the sulfidated hydrogenation transition agent MoS2 is 3.0–4.5 layers, with 1.0 layers accounting for 10%, 3.0 layers accounting for 40%, 4.0 layers accounting for 30%, and 5.0 layers accounting for 10%. The average number of active metal MoS2 lamellar crystals after sulfidation and refining is 1.0 to 2.0 layers, of which 1.0 layers account for 60% of all lamellar crystals, 2.0 layers account for 20%, 3.0 layers account for 10%, and 4.0 layers account for 10%.

[0158] Example 8

[0159] This example is a comparative test of the activity and stability of the catalyst combinations in Examples 1-7 and Comparative Examples 1-9. The evaluation was conducted on a 300mL small fixed-bed hydrogenation unit, and the properties of the feedstock are shown in Table 1.

[0160] Table 1. Main Properties of Catalytic Cracking Slurry Oil

[0161] <![CDATA[Density (20 °C), kg / m 3 > 1100 Sulfur, wt% 1.10 Nitrogen, μg / g 1900 Aromatics, wt% 71.3 Gel, wt% 16.1

[0162] The evaluation criteria are shown in Table 2.

[0163] Table 2 Evaluation Process Conditions

[0164] Pressure, MPa 8 Hydrogen-to-oil ratio (by volume) 800 Reaction temperature, °C 350 <![CDATA[Liquid hourly space velocity, h -1 > 0.7

[0165] The activity evaluation results of the catalyst combination system after 1000 hours of operation are listed in Table 3.

[0166] Table 3. Activity evaluation results of the catalyst combination system after 1000 hours of operation.

[0167]

[0168]

[0169] As can be seen from Table 3, the desulfurization rate and denitrification rate of the catalyst gradation combination in the examples are higher than those in the comparative examples; the aromatic content of the examples is also higher than that of the comparative examples. This proves that the gradation method of the heavy oil hydrotreating catalyst of the present invention has a better aromatic retention rate.

[0170] The results of the 5000-hour activity stability evaluation are listed in Table 4.

[0171] Table 4. Results of activity stability evaluation after 5000 hours

[0172]

[0173]

[0174] As shown in Table 4, with the extension of operating time, the desulfurization rate and denitrification rate of the catalyst gradation combination in the example were significantly higher than those of the comparative catalyst combination, and the aromatic content was higher than that of the comparative, exhibiting excellent impurity removal activity stability and aromatic retention rate. This is because the catalyst gradation method of the present invention effectively achieves the gradient synergy between the number of crystal layers of the catalyst active phase and the pore structure, achieving the effect of directional and precise reaction of impurities to be removed in the oil slurry.

[0175] Example 9

[0176] This example is a comparative test of the activity and stability of the catalyst combinations in Examples 1-7 and Comparative Examples 1-9. The evaluation was conducted on a 300 mL small fixed-bed hydrotreating unit, and the properties of the feedstock are shown in Table 5.

[0177] Table 5. Main Properties of Feed Oil from a Domestic Residue Hydrotreating Unit

[0178] <![CDATA[Density (20 °C), kg / m 3 > 959 sulfur,% 1.82 Nitrogen, μg / g 3500 Residual carbon, wt% 8.8 (Ni+V), wt% 30.1

[0179] The evaluation criteria are shown in Table 6.

[0180] Table 6 Evaluation Process Conditions

[0181] Pressure, MPa 13.0 Hydrogen-to-oil ratio (by volume) 1000 Reaction temperature, °C 375 <![CDATA[Liquid hourly space velocity, h -1 > 0.3

[0182] The activity evaluation results of the catalyst combination system after 1000 hours of operation are listed in Table 7.

[0183] Table 7. Activity evaluation results of the catalyst combination system after 1000 hours of operation.

[0184]

[0185]

[0186] As can be seen from Table 7, the desulfurization rate and denitrification rate of the catalyst gradation combination in the examples are higher than those of the comparative catalyst gradation combination, and the aromatic content is higher than that of the comparative example.

[0187] The results of the 5000-hour activity stability evaluation are listed in Table 8.

[0188] Table 8. Results of activity stability evaluation after 5000 hours

[0189]

[0190]

[0191] As shown in Table 8, with the extension of operating time, the desulfurization rate and denitrification rate of the catalyst gradation combination in the example are significantly higher than those in the comparative catalyst combination, and the aromatic content is higher than that in the comparative example, exhibiting excellent activity stability and aromatic retention rate. The catalyst gradation method of the present invention effectively achieves the gradient synergy between the number of crystal layers of the catalyst active phase and the pore structure, achieving the effect of directional and precise reaction of impurities to be removed in heavy oil.

[0192] As can be seen from the comparison results of Examples 1-7 and Comparative Examples 1-5 in Tables 3, 4, 7 and 8, compared with the prior art, the gradation method of the heavy oil hydrotreating catalyst of the present invention has higher desulfurization and denitrification activity and stability, better aromatics retention rate, and can effectively slow down the deactivation rate of the catalyst and extend the catalyst's operating cycle.

[0193] The comparison results of Example 1 and Comparative Examples 6-8 in Tables 3, 4, 7, and 8 show that the proportion of pore volumes of each diameter in the hydrogenation pretreatment agent, hydrogenation transition agent, and hydrogenation refining agent all affect the effect of the gradation method. If the pore volume proportion is too high or too low, the desulfurization and denitrification activity and stability of the obtained catalyst gradation combination are poor, and the aromatic hydrocarbon retention rate is low. Within the range of pore diameter distribution and pore volume proportion of the present invention, the obtained catalyst gradation combination has higher desulfurization and denitrification activity and stability, better aromatic hydrocarbon retention rate, and can effectively slow down the deactivation rate of the catalyst and extend the catalyst operating cycle.

[0194] The comparison results of Example 1 and Comparative Example 9 in Tables 3, 4, 7, and 8 show that when the average number of lamellar layers of the active phase metal flakes after sulfidation of the hydrotreating agent, hydrotreating transition agent, and hydrorefining agent is only within the range of 1.0–2.0 layers, 3.0–4.5 layers, and 1.0–2.0 layers, respectively, and other numbers of lamellar layers are included, the resulting catalyst gradation combination is poor. When the number of lamellar layers of the active phase metal flakes after sulfidation of the hydrotreating agent, hydrotreating transition agent, and hydrorefining agent is all within the range of 1.0–2.0 layers, 3.0–4.5 layers, and 1.0–2.0 layers, respectively, the resulting catalyst gradation combination has higher desulfurization and denitrification activity and stability, better aromatic hydrocarbon retention rate, and can effectively slow down the catalyst deactivation rate and extend the catalyst operating cycle.

[0195] In summary, compared with the prior art, this invention proposes a hydrogenation catalyst gradation combination that can effectively utilize the effects of various catalysts. The gradation method of this invention has better performance than the prior art. When the pore diameter distribution, pore volume ratio, and number of lamellar layers of this invention are all within the selected layer range, the obtained catalyst gradation combination has higher desulfurization and denitrification activity and stability, better aromatic hydrocarbon retention rate, and can effectively slow down the catalyst deactivation rate and extend the catalyst operating cycle.

[0196] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.

Claims

1. A method for grading a catalyst for heavy oil hydrotreating, characterized in that, include: The reactor is filled sequentially from top to bottom with hydrogenation pretreatment agent, hydrogenation transition agent, and hydrogenation refining agent. The feed stream flows from top to bottom, and the content of active metal of the catalyst gradually increases along the flow direction. The hydrogenation pretreatment agent has active phase metal flakes with a layer count of 1.0 to 2.0 after sulfidation, and the catalyst pores with a diameter of 120 nm to 320 nm account for 10% to 25% of the total pore volume. The hydrogenation transition agent has active phase metal lamellar crystals with a layer count of 3.0 to 4.5 after sulfidation, and the catalyst pores with a diameter of 6 nm to 15 nm account for 40% to 65% of the total pore volume. The hydrogenated refining agent has active phase metal flakes with a layer count of 1.0 to 2.0 after sulfidation, and catalyst pores with a diameter of 6 nm to 13 nm account for 40% to 60% of the total pore volume. In the gradation method, by weight percentage, the hydrogenation pretreatment agent accounts for 10% to 30%, the hydrogenation transition agent accounts for 20% to 45%, and the hydrogenation refining agent accounts for 40% to 70%.

2. The method for grading the heavy oil hydrotreating catalyst according to claim 1, characterized in that, The sulfidation processes of the hydrogenation pretreatment agent, the hydrogenation transition agent, and the hydrogenation refining agent are each independently selected from dry sulfidation or wet sulfidation.

3. The method for grading the heavy oil hydrotreating catalyst according to claim 1, characterized in that, The sulfiding agent used in the sulfidation process of the hydrogenation pretreatment agent, the hydrogenation transition agent, and the hydrogenation refining agent is independently selected from at least one of H2S, thiols, polysulfides, and thiophene carboxylic acid compounds.

4. The method for grading the heavy oil hydrotreating catalyst according to claim 1, characterized in that, The sulfiding agents used in the sulfidation processes of the hydrogenation pretreatment agent, the hydrogenation transition agent, and the hydrogenation refining agent are all independently disulfides.

5. The method for grading the heavy oil hydrotreating catalyst according to claim 1, characterized in that, The hydrogenation pretreatment agent uses an inorganic oxide as a carrier and a Group VIB metal and / or a Group VIII metal as an active component. Based on the weight of the catalyst, the active metal is calculated as an oxide, with the Group VIB metal at 3wt% to 26wt% and the Group VIII metal at 0.5wt% to 8wt%.

6. The method for grading the heavy oil hydrotreating catalyst according to claim 5, characterized in that, The hydrogenation pretreatment agent also includes an auxiliary agent selected from at least one of P, Si, F, and B.

7. The method for grading the heavy oil hydrotreating catalyst according to claim 1, characterized in that, The hydrogenation transition agent uses an inorganic oxide as a support and a Group VIB metal and / or a Group VIII metal as an active component. Based on the weight of the catalyst, the active metal is calculated as an oxide, with the Group VIB metal at 3wt% to 26wt% and the Group VIII metal at 0.5wt% to 8wt%.

8. The method for grading the heavy oil hydrotreating catalyst according to claim 7, characterized in that, The hydrogenation transition agent also includes an auxiliary agent selected from at least one of P, Si, F, and B.

9. The method for grading the heavy oil hydrotreating catalyst according to claim 1, characterized in that, The hydrogenated refining agent uses an inorganic oxide as a carrier and a Group VIB metal and / or a Group VIII metal as an active component. Based on the weight of the catalyst, the active metal is calculated as an oxide, with the Group VIB metal at 3wt% to 26wt% and the Group VIII metal at 0.5wt% to 8wt%.

10. The method for grading the heavy oil hydrotreating catalyst according to claim 9, characterized in that, The hydrogenated refining agent also includes an adjuvant selected from at least one of P, Si, F, and B.

11. The method for grading the heavy oil hydrotreating catalyst according to any one of claims 5, 7, and 9, characterized in that, The inorganic oxide is selected from at least one of aluminum oxide and silicon oxide, the group VIB metal is selected from at least one of W and Mo, and the group VIII metal is selected from at least one of Co and Ni.

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