Hydrogenation catalyst grading method for prolonging operation cycle of residue hydrogenation device and residue hydrotreating method

Abstract

The application provides a hydrogenation catalyst grading method and a residual oil hydroprocessing method for prolonging the operation cycle of a residual oil hydrogenation device. The hydrogenation catalyst grading method comprises the following steps: dividing four hydrogenation reactors in series into a filling area at the bottom and a reaction area above the filling area, filling metal-containing catalysts in the filling area of one or more hydrogenation reactors at the front stage of the four hydrogenation reactors in series, and filling carbon-containing catalysts in the filling area of one or more hydrogenation reactors at the rear stage; and the reaction areas of the four hydrogenation reactors in series form a total reaction area, and the total reaction area is sequentially filled with a hydrogenation protection catalyst, a hydrogenation demetallization catalyst, a hydrogenation desulfurization catalyst and a hydrogenation decarburization catalyst along the flow direction. The hydrogenation catalyst grading method provided by the application is suitable for a fixed-bed residual oil hydrogenation process, and prolongs the operation cycle of the residual oil hydrogenation device.

Description

TECHNICAL FIELD

[0001] The present application relates to a hydrogenation catalyst grading method for prolonging the operation cycle of a residual oil hydrogenation device and a residual oil hydroprocessing method, and belongs to the technical field of residual oil hydrogenation. BACKGROUND

[0002] In the petroleum refining industry, as crude oil becomes increasingly heavy and poor, residual oil hydrogenation process has gradually become a crucial processing process. The market competition is fierce, and the profit of crude oil processing process is meager. For refining enterprises, it is increasingly important to reduce the cost of crude oil processing process. The fixed bed residual oil hydrogenation process has a shorter catalyst life due to poor processing raw materials, and the catalyst needs to be replaced every year, and the consumption is large, which brings economic burden to refining enterprises. Therefore, technical personnel in the industry use various ways to improve the residual oil hydrogenation process to prolong the operation cycle of the device, so as to achieve the purpose of reducing the cost of the processing process.

[0003] At present, the main method to prolong the operation cycle of the fixed bed residual oil hydrogenation device is to improve the residual oil hydrogenation device. The first method is to cut off the reactor filled with metal impurities and carbon, such as switching the protection reactor. The second method is to remove metal impurities and carbon online, such as using a cleaning agent to clean the carbon. The third method is to increase the porosity of the catalyst bed, so that the existing catalyst can accommodate more metal impurities and carbon, such as using an upflow reactor. However, these methods all need to increase the hydrogenation reactor, which not only has high cost, but also has high operation difficulty.

[0004] In recent years, prolonging the operation cycle of the device by improving the performance and grading of residual oil hydrogenation catalysts has become a research hotspot in the industry. CN113856695A discloses a residual oil hydrogenation catalyst grading method. The method prolongs the operation cycle of the residual oil hydrogenation device by optimizing the components of the residual oil hydrogenation catalyst, especially the structure-activity relationship of the metal removal agent. However, the effect of prolonging the operation cycle of this method is limited, and the main reason is that the residual oil hydrogenation catalyst needs to consider both hydrogenation activity and stability. If the catalyst operation cycle is improved by increasing the pore volume, the hydrogenation catalytic activity will be affected. Therefore, for the existing catalyst system based on alumina carrier and active metal, there is a maximum value of the operation cycle, which is difficult to break through the upper limit.

[0005] CN107875978B discloses a grading and loading method of hydrogenation catalyst. The method is mainly for high-iron and high-calcium residual oil, and adjusts the placement position and quantity of different types of residual oil hydrogenation catalysts to improve the operation cycle. However, this grading method has too low activity for general residual oil that is not high in iron and calcium, and the temperature raising speed is too fast, which not only cannot improve the operation cycle, but also affects the operation cycle and stability.

[0006] CN109701452B discloses a gradation method for hydrotreating catalysts of paraffinic residue oil. This method is primarily designed for paraffinic residue oils, aiming to improve operating cycles by adjusting the placement and quantity of hydrotreating catalysts for different types of residue oils. However, this gradation method is too reactive for general non-paraffinic residue oils, resulting in rapid catalyst deactivation. This not only fails to improve operating cycles but also negatively impacts operating cycles and stability.

[0007] Therefore, developing a novel method for grading residue hydrotreating catalysts to improve the operating cycle of residue hydrotreating catalysts and thus enhance the economic efficiency of residue hydrotreating units remains one of the urgent problems to be solved in this field. Summary of the Invention

[0008] To address the aforementioned technical problems, the present invention aims to provide a method for hydrogenation catalyst gradation and a method for treating residue hydrotreating units, thereby extending the operating cycle of such units. The hydrogenation catalyst gradation method provided by this invention is applicable to fixed-bed residue hydrotreating processes and can extend the operating cycle of residue hydrotreating units.

[0009] To achieve the above objectives, the first aspect of the present invention provides a method for grading a hydrogenation catalyst to extend the operating cycle of a residue hydrotreating unit, comprising: dividing four hydrogenation reactors connected in series into a bottom filling zone and a reaction zone above the filling zone; filling one or more hydrogenation reactors in the front section of the four hydrogenation reactors with a metal-containing agent; filling one or more hydrogenation reactors in the rear section with a carbon-containing agent; and filling all four hydrogenation reactors in series with either a metal-containing agent or a carbon-containing agent.

[0010] The reaction zones of four hydrogenation reactors connected in series constitute a total reaction zone, in which hydrogenation protection catalyst, hydrogenation demetallization catalyst, hydrogenation desulfurization catalyst, and hydrogenation decarbonization catalyst are sequentially loaded along the flow direction.

[0011] The metal-containing agent includes at least a first alumina, which is an alumina containing mesopores and macropores;

[0012] The residual carbon agent includes at least a second alumina, which is alumina containing only mesoporous structures.

[0013] In the above-mentioned hydrogenation catalyst gradation method, preferably, the reaction zone of one or more hydrogenation reactors in the front section is sequentially filled with one or more of the following along the flow direction: hydrogenation protection catalyst, hydrogenation demetallization catalyst, and hydrogenation desulfurization catalyst; and the reaction zone of one or more hydrogenation reactors in the rear section is sequentially filled with one or more of the following along the flow direction: hydrogenation demetallization catalyst, hydrogenation desulfurization catalyst, and hydrogenation decarbonization catalyst.

[0014] In the above-mentioned hydrogenation catalyst gradation method, preferably, the metal-containing agent includes three equivalent diameters: fine, medium, and coarse. The equivalent diameter of the fine metal-containing agent is 2.5 to 3.5 mm, the equivalent diameter of the medium metal-containing agent is 5.5 to 6.5 mm, and the equivalent diameter of the coarse metal-containing agent is 11.5 to 12.5 mm.

[0015] In the above-described hydrogenation catalyst gradation method, preferably, the loading method of the metal-containing agent is as follows: coarse, medium, and fine equivalent diameter metal-containing agents are sequentially loaded from bottom to top in the loading zone of the hydrogenation reactor. More preferably, the loading method of the metal-containing agent is as follows: the coarse metal-containing agent is loaded above the outlet collector of the hydrogenation reactor; the bed volume of the medium and fine metal-containing agents is the same as the bed volume of the coarse metal-containing agent.

[0016] In the above-described hydrogenation catalyst gradation method, preferably, the loading amount of the metal-containing agent in a hydrogenation reactor is 0.5% to 3.0% of the volume of a hydrogenation reactor; more preferably, the loading amount of the metal-containing agent in a hydrogenation reactor is 1.5% to 2.5% of the volume of a hydrogenation reactor.

[0017] In the above-mentioned hydrogenation catalyst gradation method, preferably, the carbon-residual agent includes three equivalent diameters: fine, medium, and coarse. The equivalent diameter of the fine carbon-residual agent is 2.5–3.5 mm, the equivalent diameter of the medium carbon-residual agent is 5.5–6.5 mm, and the equivalent diameter of the coarse carbon-residual agent is 11.5–12.5 mm.

[0018] In the above-described hydrogenation catalyst gradation method, preferably, the loading method of the residual carbon agent is as follows: coarse, medium, and fine equivalent diameter residual carbon agents are sequentially loaded from bottom to top in the loading zone of the hydrogenation reactor. More preferably, the loading method of the residual carbon agent is as follows: the coarse residual carbon agent is loaded above the outlet collector of the hydrogenation reactor; the bed volume of the medium and fine residual carbon agents is the same as the bed volume of the coarse residual carbon agent.

[0019] In the above-described method for grading hydrogenation catalysts, preferably, the amount of the carbon-containing agent in a hydrogenation reactor is 0.5% to 3.0% of the volume of the hydrogenation reactor; more preferably, the amount of the carbon-containing agent in a hydrogenation reactor is 1.5% to 2.5% of the volume of the hydrogenation reactor.

[0020] In this invention, the equivalent diameter refers to the maximum straight-line distance between any two points on the catalyst geometry.

[0021] In the above-described hydrogenation catalyst gradation method, preferably, the first alumina comprises mesopores of 5-20 nm and macropores of 100-500 nm, and the mesopore volume is 0.60 cm³. 3Above / g, the pore size exhibits a bimodal distribution.

[0022] In the above-described hydrogenation catalyst gradation method, preferably, the metal-coating agent further includes a first active component supported on the first alumina; the first active component includes a first main active component and a first auxiliary active component, the first main active component includes molybdenum oxide and / or tungsten oxide, and the first auxiliary active component includes nickel oxide and / or cobalt oxide; based on the total weight of the metal-coating agent as 100%, the total loading of the first active component is 5% to 15%.

[0023] In the above-described hydrogenation catalyst gradation method, preferably, the first alumina further contains one or more of boron, germanium, zirconium, and phosphorus. More preferably, based on 100% of the total weight of the first alumina, the content of one or more of boron, germanium, zirconium, and phosphorus is 0.1% to 10%.

[0024] In the above-described hydrogenation catalyst gradation method, preferably, the first main active component is molybdenum oxide and the first auxiliary active component is nickel oxide.

[0025] In the above-described hydrogenation catalyst gradation method, preferably, based on the total weight of the metal-containing agent as 100%, the loading of the first main active component is 6% to 9%, and the loading of the first auxiliary active component is 1% to 3%.

[0026] In the above-described hydrogenation catalyst gradation method, preferably, the bulk density of the metal-containing agent is 0.20–0.60 g / cm³. 3 Specific surface area is 100-160 m² 2 / g.

[0027] In the above-described hydrogenation catalyst gradation method, preferably, the mesopore volume of the second alumina with a pore size of 5-15 nm accounts for 85%-95% of the total mesopore volume, and the total mesopore volume is 0.50 cm³. 3 / g or more.

[0028] In the above-described hydrogenation catalyst gradation method, preferably, the residual carbon agent further includes a second active component supported on the second alumina; the second active component includes a second main active component and a second auxiliary active component, the second main active component includes molybdenum oxide and / or tungsten oxide, and the second auxiliary active component includes nickel oxide and / or cobalt oxide; based on the total weight of the residual carbon agent as 100%, the total loading of the second active component is 10% to 25%.

[0029] In the above-described hydrogenation catalyst gradation method, preferably, the second alumina further contains one or more of boron, germanium, zirconium, and phosphorus. More preferably, based on 100% of the total weight of the second alumina, the content of one or more of boron, germanium, zirconium, and phosphorus is 0.1% to 10%.

[0030] In the above-described hydrogenation catalyst gradation method, preferably, the second main active component is molybdenum oxide and the second auxiliary active component is nickel oxide.

[0031] In the above-mentioned hydrogenation catalyst gradation method, preferably, based on the total weight of the carbon-containing agent as 100%, the loading of the second main active component is 12% to 15%, and the loading of the second auxiliary active component is 2% to 4%.

[0032] In the above-described hydrogenation catalyst gradation method, preferably, the bulk density of the residual carbon agent is 0.40–0.75 g / cm³. 3 Specific surface area is 150-250 m² 2 / g.

[0033] In the above-described hydrogenation catalyst gradation method, to achieve the goal of effectively extending the operating cycle, this invention provides different gradation schemes based on the different Ni+V metal contents in the residue feedstock. Preferably, when the Ni+V content in the residue feedstock is ≤40μg / g, the metal-containing agent is loaded in the filling zone of the first hydrogenation reactor along the flow direction, and the carbon-containing agent is loaded in the filling zones of the second, third, and fourth hydrogenation reactors; when the Ni+V content in the residue feedstock is >40μg / g and ≤70μg / g, the metal-containing agent is loaded in the filling zones of the first and second hydrogenation reactors along the flow direction, and the carbon-containing agent is loaded in the filling zones of the third and fourth hydrogenation reactors; when the Ni+V content in the residue feedstock is >70μg / g and ≤100μg / g, the metal-containing agent is loaded in the filling zones of the first, second, and third hydrogenation reactors along the flow direction, and the carbon-containing agent is loaded in the filling zone of the fourth hydrogenation reactor.

[0034] In this invention, the hydroprotection catalyst, hydrodemetallization catalyst, hydrodesulfurization catalyst, and hydrocarbon removal catalyst can be corresponding catalysts disclosed in the prior art in the field of residue hydrotreating. Preferably, the hydroprotection catalyst, hydrodemetallization catalyst, hydrodesulfurization catalyst, and hydrocarbon removal catalyst can be PHR series residue hydrotreating catalysts developed by the Petrochemical Research Institute of China Petroleum Group.

[0035] In the above-described method for grading hydrogenation catalysts, preferably, the loading amount of the hydrogenation protection catalyst is 2% to 10% of the total volume of the four hydrogenation reactors connected in series, the loading amount of the hydrogenation demetallization catalyst is 35% to 70% of the total volume of the four hydrogenation reactors connected in series, the loading amount of the hydrogenation desulfurization catalyst is 10% to 40% of the total volume of the four hydrogenation reactors connected in series, the loading amount of the hydrogenation decarbonization catalyst is 10% to 40% of the total volume of the four hydrogenation reactors connected in series, and the remaining amount of the total volume of the four hydrogenation reactors connected in series is the loading amount of the metal-containing agent and the carbon-containing agent.

[0036] In the above-described hydrogenation catalyst gradation method, preferably, the hydrogenation reactor is a fixed-bed downflow reactor.

[0037] The second aspect of the present invention provides a method for hydrotreating residual oil, comprising: under hydrotreating reaction conditions, passing residual oil feedstock and hydrogen sequentially through four hydrotreating reactors connected in series, and contacting the hydrogen with a catalyst packed in the hydrotreating reactors according to the above-mentioned hydrogenation catalyst gradation method for extending the operating cycle of the residual oil hydrotreating device to carry out a hydrogenation reaction, thereby obtaining a hydrotreating product.

[0038] In the above-mentioned method for treating residual oil hydrotreating, preferably, the residual oil feedstock includes one or a combination of several of atmospheric residue, vacuum residue, deasphalted oil, coal tar, and coal liquefaction heavy oil.

[0039] In the above-mentioned method for treating residual oil hydrotreating, preferably, the S content in the residual oil feedstock is less than 4.5% by weight, the MCR is less than 18% by weight, and the Ni+V content is less than 100 μg / g.

[0040] In the above-described method for hydrotreating residual oil, preferably, the hydrotreating reaction conditions include: a hydrogen partial pressure of 10.0 MPa to 18.0 MPa, a hydrogen-to-oil volume ratio of 200 to 2000, and a liquid hourly space velocity of 0.10 to 1.0 h⁻¹. -1 The reaction temperature of the first hydrogenation reactor is 310–420°C, and the reaction temperature of the other hydrogenation reactors is 300–420°C. More preferably, the hydrogenation reaction conditions include: a hydrogen partial pressure of 13.0 MPa–15.0 MPa, a hydrogen-to-oil volume ratio of 420–1500, and a liquid hourly space velocity of 0.14–0.45 h⁻¹. -1 The reaction temperature of the first hydrogenation reactor was 360–420°C, while the reaction temperature of the other hydrogenation reactors was 315–410°C.

[0041] It should be noted that the hydrogenation reaction conditions of each hydrogenation reactor can be the same or different, as long as they are within the above range.

[0042] This invention provides a method for grading hydrogenation catalysts to extend the operating cycle of a residue hydrotreating unit, and a method for treating residue hydrotreating. Addressing the need to extend the operating cycle of residue hydrotreating units in the petroleum refining industry, this invention proposes replacing the ceramic balls at the bottom of the hydrotreating reactor with metal-containing and carbon-containing agents, forming a new gradation with the existing hydroprotective catalyst, hydrodemetallization catalyst, hydrodesulfurization catalyst, and hydrodecarbonization catalyst in the hydrotreating reactor. The equivalent diameter of the metal-containing and carbon-containing agents in this invention is the same as or similar to the diameter of the original ceramic balls at the bottom of the hydrotreating reactor, and their strength meets the basic requirements for supporting the main components of the residue hydrotreating catalyst (i.e., the hydroprotective catalyst, hydrodemetallization catalyst, hydrodesulfurization catalyst, and hydrodecarbonization catalyst). Furthermore, the hydrogenation catalyst gradation method of this invention can accommodate more metal impurities and carbon deposits, significantly extending the operating cycle of the residue hydrotreating unit.

[0043] The technical solution of the present invention has at least the following beneficial effects:

[0044] First, this invention is mainly based on the phenomenon of high accumulation of metal impurities and high carbon deposits caused by changes in the flow direction of the bottom material in a fixed-bed downflow reactor. The invention has developed a hydrogenation catalyst gradation method. Under the synergistic effect of the catalyst gradation method of this invention, not only can the metal impurities and carbon deposits at the bottom of the reactor be effectively removed, but the ability of the entire residue hydrogenation system to efficiently remove and accommodate metal impurities and carbon deposits can also be improved.

[0045] Secondly, compared with the conventional residue oil hydrogenation catalyst gradation system, the hydrogenation catalyst gradation system of the present invention adds metal-containing agents and carbon-containing agents, which improves the ability of the residue oil hydrogenation catalyst system to contain metal impurities and carbon deposits, extends the operating cycle of the residue oil hydrogenation unit, increases the operating efficiency of the residue oil hydrogenation unit, improves economic efficiency, and achieves the effect of reducing costs and increasing efficiency for heavy oil processing enterprises. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the filling method of the metal-containing agent in the filling area at the bottom of the hydrogenation reactor according to a specific embodiment of the present invention.

[0047] Figure 2 This is a schematic diagram of the filling method of the residual carbon agent in the filling area at the bottom of the hydrogenation reactor according to a specific embodiment of the present invention. Detailed Implementation

[0048] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0049] The first aspect of the present invention provides a method for grading a hydrogenation catalyst to extend the operating cycle of a residue hydrotreating unit, comprising: dividing four hydrogenation reactors connected in series into a bottom filling zone and a reaction zone above the filling zone; filling one or more hydrogenation reactors in the front section of the four hydrogenation reactors with a metal-containing agent; filling one or more hydrogenation reactors in the rear section with a carbon-containing agent; and filling all four hydrogenation reactors in series with either a metal-containing agent or a carbon-containing agent.

[0050] The reaction zones of four hydrogenation reactors connected in series constitute a total reaction zone, in which hydrogenation protection catalyst, hydrogenation demetallization catalyst, hydrogenation desulfurization catalyst and hydrogenation decarbonization catalyst are sequentially packed along the flow direction.

[0051] The metal-containing agent includes at least a first alumina, which is an alumina containing mesopores and macropores;

[0052] The residual carbon agent includes at least a second alumina, which is alumina containing only mesoporous structures.

[0053] In this invention, none of the four hydrogenation reactors connected in series are filled with conventional ceramic balls.

[0054] In this invention, the upstream one or more hydrogenation reactors are generally hydrogenation reactors with high metal impurity content, and the downstream one or more hydrogenation reactors are generally hydrogenation reactors with high carbon deposit content.

[0055] In this invention, the reaction zone of one or more hydrogenation reactors in the front section is sequentially filled with one or more of the following along the flow direction: a hydrogenation protection catalyst, a hydrogenation demetallization catalyst, and a hydrogenation desulfurization catalyst. The reaction zone of one or more hydrogenation reactors in the rear section is sequentially filled with one or more of the following along the flow direction: a hydrogenation demetallization catalyst, a hydrogenation desulfurization catalyst, and a hydrogenation decarbonization catalyst.

[0056] In existing fixed-bed residue hydrotreating processes, the basic principle of catalyst gradation is to decrease the catalyst pore size, increase the active component content, and decrease the catalyst particle size along the feed direction. However, industrial application results show that traditional fixed-bed residue hydrotreating units, when processing Middle Eastern vacuum residue meeting the upper limit of feed conditions (with an S content of 4.5 wt%, MCR of 18 wt%, and Ni+V content of 100 μg / g), will not have a maximum operating cycle of more than 10,000 hours (approximately 14 months), even with the optimal catalyst gradation currently available. This is because the pressure drop in the residue hydrotreating catalyst bed rises to the upper limit due to the deposition of metallic impurities and carbon deposits, forcing a shutdown. Modern refineries, in pursuit of maximum economic benefits, often require residue hydrotreating units to process vacuum residue close to the upper limit of feed conditions; therefore, the need for technologies to extend operating cycles is quite urgent.

[0057] Through in-depth research, the inventors of this invention discovered that the deposited metallic Ni and V, as well as coke, in the catalyst of a fixed-bed residue hydrotreating reactor are not evenly distributed in the catalyst bed, especially exhibiting a concentrated distribution at the bottom of the reactor. The main reason is the change in the flow direction of the bottom stream in a fixed-bed downflow reactor, gradually transitioning from axial flow to radial flow, leading to a significant increase in the amount of metallic impurities and coke deposits. Therefore, this invention replaces the ceramic balls at the bottom of the reactor, which cannot accommodate metallic impurities and coke, with metal-containing and carbon-containing agents, forming a new gradation with the existing protective agents, demetallizing agents, desulfurizing agents, and carbon-containing agents in the reactor. The metal-containing agent of this invention includes alumina with both mesoporous and macroporous structures, which has a high capacity for containing metals; the carbon-containing agent includes alumina with only mesoporous structures, which has a high capacity for containing carbon residues. Therefore, the gradation method of this invention significantly improves the capacity of the entire catalyst series to contain metallic impurities and coke, delaying the rise in bed pressure drop, thereby significantly extending the operating cycle of the residue hydrotreating unit, meeting the requirements for extended operating cycles of atmospheric and vacuum residue hydrotreating units commonly used in the petroleum refining industry.

[0058] In some specific embodiments of the present invention, the metal-containing agent includes three types of metal-containing agents with equivalent diameters of fine, medium and coarse; the equivalent diameter of the fine metal-containing agent is 2.5 to 3.5 mm; the equivalent diameter of the medium metal-containing agent is 5.5 to 6.5 mm; and the equivalent diameter of the coarse metal-containing agent is 11.5 to 12.5 mm.

[0059] In some specific embodiments of the present invention, the loading method of the metal-containing agent is as follows: coarse, medium, and fine equivalent diameter metal-containing agents are sequentially loaded from bottom to top in the loading zone of the hydrogenation reactor. Preferably, the loading method of the metal-containing agent is as follows: the coarse metal-containing agent is loaded above the outlet collector of the hydrogenation reactor (the loading amount of the coarse metal-containing agent can reach the junction of the bottom surface and the side wall of the hydrogenation reactor), more preferably, the distance between the upper surface of the coarse metal-containing agent bed and the lowest point of the bottom surface of the hydrogenation reactor is 150-300 mm; the bed volume of the neutral and fine metal-containing agents is the same as the bed volume of the coarse metal-containing agent. According to specific embodiments of the present invention, the loading method of the metal-containing agent in the loading zone of the hydrogenation reactor is as follows: Figure 1 As shown. Figure 1 The main catalysts in the process include one or more of the following: hydroprotection catalysts, hydrodemetallization catalysts, and hydrodesulfurization catalysts.

[0060] In some specific embodiments of the present invention, the loading amount of the metal-containing agent (including coarse, medium and fine equivalent diameter metal-containing agents) in a hydrogenation reactor is 0.5% to 3.0% of the volume of a hydrogenation reactor, preferably 1.5% to 2.5%.

[0061] In some specific embodiments of the present invention, the char-residue agent includes three equivalent diameters: fine, medium, and coarse. The equivalent diameter of the fine char-residue agent is 2.5 to 3.5 mm, the equivalent diameter of the medium char-residue agent is 5.5 to 6.5 mm, and the equivalent diameter of the coarse char-residue agent is 11.5 to 12.5 mm.

[0062] In some specific embodiments of the present invention, the loading method of the carbon-containing agent is as follows: three types of carbon-containing agents with equivalent diameters of coarse, medium, and fine are sequentially loaded from bottom to top in the loading zone of the hydrogenation reactor. Preferably, the loading method of the carbon-containing agent is as follows: the coarse carbon-containing agent is loaded above the outlet collector of the hydrogenation reactor (the upper surface of the coarse carbon-containing agent bed can be perpendicular to the tangent at the intersection of the hydrogenation reactor wall and the bed), more preferably, the distance from the upper surface of the coarse carbon-containing agent bed to the lowest point of the bottom surface of the hydrogenation reactor is 150-300 mm; the bed volume of the neutral and fine carbon-containing agents is the same as the bed volume of the coarse carbon-containing agent. According to specific embodiments of the present invention, the loading method of the carbon-containing agent in the loading zone of the hydrogenation reactor is as follows: Figure 2 As shown. Figure 2 The main catalysts include one or more of the following: hydrodemetallization catalysts, hydrodesulfurization catalysts, and hydrodecarbonization catalysts.

[0063] In some specific embodiments of the present invention, the amount of the carbon-containing agent (including coarse, medium and fine equivalent diameter carbon-containing agents) in a hydrogenation reactor is 0.5% to 3.0% of the volume of a hydrogenation reactor, preferably 1.5% to 2.5%.

[0064] In this invention, the equivalent diameter refers to the maximum straight-line distance between any two points on the catalyst geometry.

[0065] In some specific embodiments of the present invention, the first alumina comprises mesopores of 5-20 nm and macropores of 100-500 nm, and the mesopore volume is 0.60 cm³. 3 Above / g, the pore size exhibits a bimodal distribution.

[0066] In some specific embodiments of the present invention, the metal-coating agent further includes a first active component supported on the first alumina; the first active component includes a first main active component and a first auxiliary active component, the first main active component includes molybdenum oxide and / or tungsten oxide, and the first auxiliary active component includes nickel oxide and / or cobalt oxide; based on the total weight of the metal-coating agent as 100%, the total loading of the first active component is 5% to 15%. The metal-coating agent of the present invention may include an active component, thereby possessing a certain catalytic hydrogenation function.

[0067] In some specific embodiments of the present invention, the second alumina further contains one or more of boron, germanium, zirconium, and phosphorus. Preferably, based on 100% of the total weight of the second alumina, the content of one or more of boron, germanium, zirconium, and phosphorus is 0.1% to 10%. The second alumina can be modified by introducing one or more of boron, germanium, zirconium, and phosphorus using methods found in the prior art.

[0068] In some specific embodiments of the present invention, the second main active component is molybdenum oxide, and the second auxiliary active component is nickel oxide.

[0069] In some specific embodiments of the present invention, based on the total weight of the metal-containing agent as 100%, the loading of the second main active component is 6% to 9%, and the loading of the second auxiliary active component is 1% to 3%.

[0070] In some specific embodiments of the present invention, the bulk density of the metal-containing agent is 0.20–0.60 g / cm³. 3 Specific surface area is 100-160 m² 2 / g.

[0071] In some specific embodiments of the present invention, the metal-containing agent can be in the shape of a four-leaf clover, a strip, or a sphere. Metal-containing agents with a certain shape can be prepared using conventional molding methods, such as, but not limited to, extrusion molding.

[0072] The present invention does not impose any particular limitation on the preparation method of the metal-coating agent, as long as the specific metal-coating agent described above can be prepared.

[0073] According to some preferred embodiments of the present invention, the method for preparing the metal-containing agent includes:

[0074] First, alumina with the required physicochemical properties is prepared from boehmite using molding, drying, and calcination methods. Then, the first main active component and the first auxiliary active component are selectively distributed to form an impregnation solution, and the metal-containing agent is prepared by an equal-volume impregnation method.

[0075] In some specific embodiments of the present invention, the pore volume of mesopores with a pore size of 5-15 nm in the second alumina accounts for 85%-95% of the total mesopore volume, and the total mesopore volume is 0.50 cm³. 3 / g or more. The mesopores contained in this second alumina are mainly distributed in the range of 5-15 nm, and the distribution is concentrated.

[0076] In some specific embodiments of the present invention, the carbonizing agent further includes a second active component loaded on the second alumina; the second active component includes a second main active component and a second auxiliary active component, the second main active component includes molybdenum oxide and / or tungsten oxide, and the second auxiliary active component includes nickel oxide and / or cobalt oxide; based on the total weight of the carbonizing agent as 100%, the total loading of the second active component is 10% to 25%.

[0077] In some specific embodiments of the present invention, the second alumina further contains one or more of boron, germanium, zirconium, and phosphorus. Preferably, based on 100% of the total weight of the second alumina, the content of one or more of boron, germanium, zirconium, and phosphorus is 0.1% to 10%. The second alumina can be modified by introducing one or more of boron, germanium, zirconium, and phosphorus using methods found in the prior art.

[0078] In some specific embodiments of the present invention, the second main active component is molybdenum oxide, and the second auxiliary active component is nickel oxide.

[0079] In some specific embodiments of the present invention, based on the total weight of the carbonizing agent as 100%, the loading of the second main active component is 12% to 15%, and the loading of the second auxiliary active component is 2% to 4%.

[0080] In some specific embodiments of the present invention, the bulk density of the residual char agent is 0.40–0.75 g / cm³. 3 Specific surface area is 150-250 m² 2 / g.

[0081] In some specific embodiments of the present invention, the shape of the char-forming agent can be clover-shaped, strip-shaped, or spherical, etc. The char-forming agent with a certain shape can be prepared using conventional molding methods, such as, but not limited to, extrusion molding.

[0082] The present invention does not impose any particular limitation on the preparation method of the aforementioned carbonizing agent, as long as the specific carbonizing agent can be prepared.

[0083] According to some preferred embodiments of the present invention, the method for preparing the residual char agent includes:

[0084] First, a second alumina with the required physicochemical properties is prepared from boehmite using molding, drying, and calcination methods. Then, the second main active component and the second auxiliary active component are selectively distributed to form an impregnation solution, and the aforementioned carbonizing agent is prepared using an equal-volume impregnation method.

[0085] Fixed-bed residue hydrotreating units typically employ four hydrotreating reactors. In industrial applications, conventional residue hydrotreating catalyst gradations often result in the following issues: when the residue feedstock has a high Ni+V content, the catalyst bed in one or more upstream reactors experiences excessive accumulation of metal impurities, causing the pressure drop to reach its upper limit first. Conversely, when processing residue feedstocks with low Ni+V content, the pressure drop in one or more downstream reactors reaches its upper limit first due to excessive accumulation of carbon deposits.

[0086] In order to delay the reactor pressure drop from reaching its upper limit, the present invention fills the bottom of one or more reactors with high metal impurity content (i.e., the filling zone) in the front section with a metal dissolving agent, and fills the bottom of one or more reactors with high carbon deposit content (i.e., the filling zone) in the rear section with a carbon residue dissolving agent.

[0087] To achieve the goal of effectively extending the operating cycle, this invention provides different gradation schemes based on the varying Ni+V content in the residue feedstock. When the Ni+V content in the residue feedstock is ≤40 μg / g, preferably, the metal-dissolving agent is loaded in the filling zone of the first hydrotreating reactor along the flow direction, and the carbon-dissolving agent is loaded in the filling zones of the second, third, and fourth hydrotreating reactors. When the Ni+V content in the residue feedstock is >40 μg / g and ≤70 μg / g, preferably, the metal-dissolving agent is loaded in the filling zones of the first and second hydrotreating reactors along the flow direction, and the carbon-dissolving agent is loaded in the filling zones of the third and fourth hydrotreating reactors. When the Ni+V content in the residue feedstock is >70 μg / g and ≤100 μg / g, preferably, the metal-dissolving agent is loaded in the filling zones of the first, second, and third hydrotreating reactors along the flow direction, and the carbon-dissolving agent is loaded in the filling zone of the fourth hydrotreating reactor.

[0088] In this invention, the hydroprotection catalyst, hydrodemetallization catalyst, hydrodesulfurization catalyst, and hydrocarbon removal catalyst can be corresponding catalysts disclosed in the prior art in the field of residue hydrotreating. In some preferred embodiments of this invention, the hydroprotection catalyst, hydrodemetallization catalyst, hydrodesulfurization catalyst, and hydrocarbon removal catalyst are PHR series residue hydrotreating catalysts developed by the Petrochemical Research Institute of China National Petroleum Corporation.

[0089] In some specific embodiments of the present invention, the loading amount of the hydrogenation protection catalyst is 2% to 10% of the total volume of the four hydrogenation reactors connected in series, the loading amount of the hydrogenation demetallization catalyst is 35% to 70% of the total volume of the four hydrogenation reactors connected in series, the loading amount of the hydrogenation desulfurization catalyst is 10% to 40% of the total volume of the four hydrogenation reactors connected in series, the loading amount of the hydrogenation decarbonization catalyst is 10% to 40% of the total volume of the four hydrogenation reactors connected in series, and the remaining amount of the total volume of the four hydrogenation reactors connected in series is the loading amount of the metal-containing agent and the carbon-containing agent.

[0090] In some specific embodiments of the present invention, the hydrogenation reactor is a fixed-bed downflow reactor. A downflow reactor is a reactor in which the material flows from top to bottom. In the residue hydrogenation process, the flow pattern of the material at the bottom of the downflow reactor changes from axial flow to radial flow. The hydrogenation catalyst gradation method of the present invention is applicable to fixed-bed downflow reactors.

[0091] The second aspect of the present invention provides a method for hydrotreating residual oil, comprising: under hydrotreating reaction conditions, passing residual oil feedstock and hydrogen sequentially through four hydrotreating reactors connected in series, and contacting the hydrogen with a catalyst packed in the hydrotreating reactors according to the above-mentioned hydrogenation catalyst gradation method for extending the operating cycle of the residual oil hydrotreating device to carry out a hydrogenation reaction, thereby obtaining a hydrotreating product.

[0092] In some specific embodiments of the present invention, the residue feedstock includes one or a combination of several of atmospheric residue, vacuum residue, deasphalted oil, coal tar, and coal liquefaction heavy oil. Preferably, the residue feedstock is vacuum residue.

[0093] In some specific embodiments of the present invention, the S content in the residual oil feedstock is less than 4.5% by weight, the MCR is less than 18% by weight, and the Ni+V content is less than 100 μg / g.

[0094] In some specific embodiments of the present invention, the hydrogenation reaction conditions include: a hydrogen partial pressure of 10.0 MPa to 18.0 MPa, a hydrogen-to-oil volume ratio of 200 to 2000, and a liquid hourly space velocity of 0.10 to 1.0 h⁻¹. -1 The reaction temperature of the first hydrogenation reactor is 310–420°C, and the reaction temperature of the other hydrogenation reactors is 300–420°C. Preferably, the hydrogenation reaction conditions include: a hydrogen partial pressure of 13.0 MPa–15.0 MPa, a hydrogen-to-oil volume ratio of 420–1500, and a liquid hourly space velocity of 0.14–0.45 h⁻¹. -1 The reaction temperature of the first hydrogenation reactor was 360–420°C, while the reaction temperature of the other hydrogenation reactors was 315–410°C.

[0095] It should be noted that the hydrogenation reaction conditions of each hydrogenation reactor can be the same or different, as long as they are within the above range.

[0096] The technical solutions of the present invention are illustrated in detail below through embodiments and comparative examples. However, the present invention is not limited to these embodiments, and various modifications can be made within the scope of the key points of the present invention.

[0097] The main hydrogenation catalysts used in the examples and comparative examples are the PHR series residue hydrogenation catalysts developed by the Petrochemical Research Institute of China National Petroleum Corporation and produced by the Catalyst Plant of Fushun Petrochemical Company of China National Petroleum Corporation; among them, the hydrogenation protection catalyst is PHR-404, the hydrogenation demetallization catalysts are PHR-101, PHR-102, PHR-103 and PHR-104, the hydrogenation desulfurization catalysts are PHR-201, PHR-202 and PHR-203, and the hydrogenation decarbonization catalyst is PHR-301.

[0098] In the examples and comparative examples, residue feedstock A was a mixed vacuum residue from the Middle East, and residue feedstock B was an atmospheric residue from the Middle East. The properties of residue feedstock A and residue feedstock B are shown in Table 1.

[0099] Example 1

[0100] This embodiment provides a method for grading a hydrogenation catalyst to extend the operating cycle of a residue hydrotreating unit. This method uses four fixed-bed downflow reactors, each with a volume of 300 ml, connected in series. The four reactors are named reactor a, reactor b, reactor c, and reactor d from front to back. Each of the four series-connected hydrogenation reactors is divided into a bottom packing zone and a reaction zone above the packing zone. Reactors a, b, and c are each filled with 2 ml of coarse, medium, and fine equivalent diameter metal-containing agents sequentially from bottom to top. Reactor d is filled with 2 ml of coarse, medium, and fine equivalent diameter carbon-containing agents sequentially from bottom to top. The equivalent diameter of the fine metal-containing agent is 3 mm, the medium is 6 mm, and the coarse is 12 mm. The equivalent diameter of the fine carbon-containing agent is 3 mm, the medium is 6 mm, and the coarse is 12 mm.

[0101] The reaction zones of reactors a, b, c, and d constitute the total reaction zone. In the total reaction zone, the following catalysts are sequentially loaded along the flow direction: hydrogenation protection catalyst PHR-404, hydrogenation demetallization catalysts PHR-101, PHR-102, PHR-103, and PHR-104, hydrogenation desulfurization catalysts PHR-201, PHR-202, and PHR-203, and hydrogenation residual carbon removal catalyst PHR-301. The total filling volume of PHR-404 accounts for 5% of the total volume of the four reactors; the total filling volume of PHR-101, PHR-102, PHR-103, and PHR-104 accounts for 53% of the total volume of the four reactors, and the filling volume ratio of PHR-101, PHR-102, PHR-103, and PHR-104 is 1:1:5:5; the total filling volume of PHR-201, PHR-202, PHR-203, and PHR-301 accounts for 40% of the total volume of the four reactors, and the filling volume ratio of PHR-201, PHR-202, PHR-203, and PHR-301 is 1:1:1:3.

[0102] The metal-coating agent comprises a first alumina and a first active component supported on the first alumina; the first active component comprises a first primary active component and a first secondary active component, the first primary active component being molybdenum oxide and the first secondary active component being nickel oxide; based on the total weight of the metal-coating agent being 100%, the total loading of the first active component is 10%, wherein the loading of the first primary active component is 8% and the loading of the first secondary active component is 2%.

[0103] The first alumina comprises mesopores of 5–20 nm and macropores of 100–500 nm, with the mesopore volume being 0.60–0.70 cm³. 3 / g, the pore size exhibits a bimodal distribution.

[0104] The bulk density of the metal-containing agent is 0.58–0.60 g / cm³. 3 Specific surface area is 120-140 m² 2 / g.

[0105] The metal-containing agent is shaped like a four-leaf clover.

[0106] The preparation method of the metal-containing agent includes the following steps: First, a pure alumina carrier (i.e., the first alumina) with the required physicochemical properties is prepared by means of extrusion molding and drying calcination using boehmite as raw material. Then, the first main active component and the first auxiliary active component are prepared into an impregnation solution, and the metal-containing agent is prepared by equal volume impregnation method.

[0107] The residual char agent comprises a second alumina and a second active component supported on the second alumina; the second active component comprises a second main active component and a second auxiliary active component, the second main active component being molybdenum oxide and the second auxiliary active component being nickel oxide; based on the total weight of the residual char agent being 100%, the total loading of the second active component is 17%, of which the loading of the second main active component is 14% and the loading of the second auxiliary active component is 3%.

[0108] The second alumina contains only mesopores, with mesopores having a pore size of 5–15 nm accounting for 90% of the total mesopore volume, and the total mesopore volume being 0.50–0.60 cm³. 3 / g.

[0109] The bulk density of the residual char agent is 0.70–0.75 g / cm³. 3 Specific surface area is 180-200 m² 2 / g.

[0110] The charcoal-containing agent is shaped like a four-leaf clover.

[0111] The preparation method of the carbon-containing agent includes the following steps: First, a pure alumina carrier (i.e., second alumina) with physicochemical properties meeting the requirements is prepared by means of extrusion molding and drying calcination. Then, the second main active component and the second auxiliary active component are divided into impregnation solution, and the metal-containing agent is prepared by equal volume impregnation method.

[0112] This embodiment also provides a method for hydrotreating residual oil, which includes: under hydrotreating reaction conditions, passing residual oil feedstock A and hydrogen gas sequentially through the above-mentioned four reactors a, b, c and d connected in series, and contacting the hydrogenation reaction with the catalysts packed in reactors a, b, c and d according to the above-mentioned hydrogenation catalyst gradation method to obtain hydrotreating residual oil.

[0113] In each reactor, the residual oil feedstock A and hydrogen flow in a top-down manner.

[0114] The hydrogenation reaction conditions include: a hydrogen partial pressure of 15.0 MPa, a hydrogen-to-oil volume ratio of 700:1, and a liquid hourly space velocity of 0.217 h⁻¹. -1 The reaction temperature is 380℃. The reaction conditions are the same for reactors a, b, c, and d.

[0115] The pressure drop of each reactor was 0.18 MPa in the initial stage of operation. The reactor was shut down when the pressure drop of reactor a rose to 0.7 MPa. The calculated operating time was 12,000 hours.

[0116] Example 2

[0117] This embodiment provides a method for grading a hydrogenation catalyst to extend the operating cycle of a residue hydrotreating unit. The method employs four 300ml fixed-bed downflow reactors connected in series. The four reactors are named reactor a, reactor b, reactor c, and reactor d from front to back. Each of the four reactors is divided into a bottom packing zone and a reaction zone above the packing zone. Reactor a's packing zone is filled with 2ml each of coarse, medium, and fine equivalent diameter metal-containing agents from bottom to top. Reactors b, c, and d's packing zones are each filled with 2ml each of coarse, medium, and fine equivalent diameter carbon-containing agents from bottom to top. The equivalent diameter of the fine metal-containing agent is 3mm, the medium is 6mm, and the coarse is 12mm. The equivalent diameter of the fine carbon-containing agent is 3mm, the medium is 6mm, and the coarse is 12mm.

[0118] The reaction zones of reactors a, b, c, and d constitute the total reaction zone. In the total reaction zone, the following catalysts are sequentially loaded along the flow direction: hydrogenation protection catalyst PHR-404, hydrogenation demetallization catalysts PHR-101, PHR-102, PHR-103, and PHR-104, hydrogenation desulfurization catalysts PHR-201, PHR-202, and PHR-203, and hydrogenation residual carbon removal catalyst PHR-301. The total filling volume of PHR-404 accounts for 5% of the total volume of the four reactors; the total filling volume of PHR-101, PHR-102, PHR-103 and PHR-104 accounts for 40% of the total volume of the four reactors, and the filling volume ratio of PHR-101, PHR-102, PHR-103 and PHR-104 is 1:1:5:5; the total filling volume of PHR-201, PHR-202, PHR-203 and PHR-301 accounts for 53% of the total volume of the four reactors, and the filling volume ratio of PHR-201, PHR-202, PHR-203 and PHR-301 is 1:1:1:3.

[0119] The metal-containing agent and carbon-containing agent of this embodiment, and their preparation methods are the same as those of Example 1.

[0120] The hydrogenation catalyst gradation method of this embodiment is used to process residue oil feedstock B, and the process conditions for residue oil hydrogenation are the same as in Example 1.

[0121] The pressure drop of each reactor was 0.18 MPa at the beginning of operation. The reactor was shut down when the pressure drop of reactor d rose to 0.7 MPa. The calculated operating time was 15,000 hours.

[0122] Example 3

[0123] This embodiment provides a method for grading a hydrogenation catalyst to extend the operating cycle of a residue hydrotreating unit. This method uses four fixed-bed downflow reactors, each with a volume of 300 ml, connected in series. The four reactors are named reactor a, reactor b, reactor c, and reactor d from front to back. Each of the four series-connected hydrogenation reactors is divided into a bottom packing zone and a reaction zone above the packing zone. Reactors a, b, and c are each filled with 2 ml of coarse, medium, and fine equivalent diameter metal-containing agents sequentially from bottom to top. Reactor d is filled with 2 ml of coarse, medium, and fine equivalent diameter carbon-containing agents sequentially from bottom to top. The equivalent diameter of the fine metal-containing agent is 3 mm, the medium is 6 mm, and the coarse is 12 mm. The equivalent diameter of the fine carbon-containing agent is 3 mm, the medium is 6 mm, and the coarse is 12 mm. The main catalyst (i.e., the hydrogenation protection catalyst, the hydrogenation demetallization catalyst, the hydrogenation desulfurization catalyst, and the hydrogenation decarbonization catalyst) was loaded in the same manner as in Example 1.

[0124] The difference between this embodiment and Embodiment 1 is that the active component content of the metal-containing agent and the carbon-containing agent is appropriately increased; the loading of the first main active component in the metal-containing agent is 9%, and the loading of the second auxiliary active component is 3%; the loading of the second main active component in the carbon-containing agent is 15%, and the loading of the second auxiliary active component is 4%.

[0125] The hydrogenation catalyst gradation method was used to process residue oil feedstock A, and the hydrogenation process conditions for residue oil were the same as in Example 1.

[0126] The pressure drop of each reactor was 0.18 MPa in the initial stage of operation. The reactor was shut down when the pressure drop of reactor a rose to 0.7 MPa. The calculated operating time was 11,900 hours.

[0127] Example 4

[0128] This embodiment provides a method for grading a hydrogenation catalyst to extend the operating cycle of a residue hydrotreating unit. This method uses four fixed-bed downflow reactors, each with a volume of 300 ml, connected in series. The four reactors are named reactor a, reactor b, reactor c, and reactor d from front to back. Each of the four series-connected hydrogenation reactors is divided into a bottom packing zone and a reaction zone above the packing zone. Reactors a, b, and c are each filled with 2 ml of coarse, medium, and fine equivalent diameter metal-containing agents sequentially from bottom to top. Reactor d is filled with 2 ml of coarse, medium, and fine equivalent diameter carbon-containing agents sequentially from bottom to top. The equivalent diameter of the fine metal-containing agent is 3 mm, the medium is 6 mm, and the coarse is 12 mm. The equivalent diameter of the fine carbon-containing agent is 3 mm, the medium is 6 mm, and the coarse is 12 mm. The main catalyst (i.e., the hydrogenation protection catalyst, the hydrogenation demetallization catalyst, the hydrogenation desulfurization catalyst, and the hydrogenation decarbonization catalyst) was loaded in the same manner as in Example 1.

[0129] The difference between this embodiment and Embodiment 1 is that the specific surface area of ​​the metal-containing agent and the carbon-containing agent is appropriately increased; the specific surface area of ​​the metal-containing agent is 140–160 m². 2 / g; the specific surface area of ​​the residual charcoal agent is 200-220m². 2 / g.

[0130] The hydrogenation catalyst gradation method was used to process residue oil feedstock A, and the hydrogenation process conditions for residue oil were the same as in Example 1.

[0131] The pressure drop of each reactor was 0.18 MPa at the beginning of operation. The reactor was shut down when the pressure drop of reactor a rose to 0.7 MPa. The calculated operating time was 11,920 hours.

[0132] Example 5

[0133] This embodiment provides a method for grading hydrogenation catalysts to extend the operating cycle of a residue hydrotreating unit. This method uses four fixed-bed downflow reactors, each with a volume of 300 ml, connected in series. The four reactors are named reactor a, reactor b, reactor c, and reactor d from front to back. The catalyst gradation and physicochemical properties of the four reactors are exactly the same as in Example 1.

[0134] The hydrogenation catalyst gradation method was used to process residue feedstock A, but the reaction conditions for residue hydrogenation differed from those in Example 1. The reaction conditions in this example included: a hydrogen partial pressure of 18.0 MPa, a hydrogen-to-oil volume ratio of 1000:1, and a liquid hourly space velocity of 0.217 h⁻¹. -1The reaction temperature was 380°C, and other reaction conditions were exactly the same as in Example 1, and the reaction conditions in reactors a, b, c and d were the same.

[0135] The pressure drop of each reactor was 0.18 MPa in the initial stage of operation. The reactor was shut down when the pressure drop of reactor a rose to 0.7 MPa. The calculated operating time was 12,000 hours.

[0136] Example 6

[0137] This embodiment provides a method for grading hydrogenation catalysts to extend the operating cycle of a residue hydrotreating unit. The method uses four fixed-bed downflow reactors, each with a volume of 300 ml, connected in series. The four reactors are named reactor a, reactor b, reactor c, and reactor d from front to back. The catalyst gradation and physicochemical properties of the four reactors are exactly the same as in Example 1.

[0138] The hydrogenation catalyst gradation method was used to process residue feedstock A, but the reaction conditions for residue hydrogenation differed from those in Example 1. The reaction conditions in this example included: a hydrogen partial pressure of 15.0 MPa, a hydrogen-to-oil volume ratio of 700:1, and a liquid hourly space velocity of 0.5 h⁻¹. -1 The reaction temperature was 390°C, and other reaction conditions were exactly the same as in Example 1, and the reaction conditions in reactors a, b, c and d were the same.

[0139] The pressure drop of each reactor was 0.18 MPa at the beginning of operation. The reactor was shut down when the pressure drop of reactor a rose to 0.7 MPa. The calculated operating time was 11,100 hours.

[0140] The properties of the hydrotreated residue oils provided in Examples 1 to 6 are shown in Table 1.

[0141] Table 1 Properties of residue feedstock and hydrotreated residue from Examples 1-6

[0142]

[0143]

[0144] As can be seen from the operating results of Examples 1 to 6, when producing hydrotreated residue oil with the same properties, by changing the physical properties of the metal-containing agent and the carbon-containing agent, as well as the hydrotreating reaction conditions within the scope of this invention, the hydrotreating catalyst gradation method provided by this invention can improve the operating time of the residue oil hydrotreating unit.

[0145] Comparative Example 1

[0146] This comparative example provides a method for grading a hydrogenation catalyst. This method utilizes four 300 ml fixed-bed downflow reactors connected in series. The four reactors are named reactor a, reactor b, reactor c, and reactor d from front to back. The four hydrogenation reactors are divided into a bottom packing zone and a reaction zone above the packing zone. The packing zones of reactors a, b, c, and d are all packed sequentially from bottom to top. and Each of the ceramic balls (inert alumina ceramic balls) contains 2 ml. The main catalyst (i.e., the hydrogenation protection catalyst, the hydrogenation demetallization catalyst, the hydrogenation desulfurization catalyst, and the hydrogenation decarbonization catalyst) is packed in the same way as in Example 1.

[0147] The hydrogenation catalyst gradation method was used to process residue oil feedstock A, and the hydrogenation process conditions for residue oil were the same as in Example 1.

[0148] The pressure drop of each reactor was 0.18 MPa at the beginning of operation. The reactor was shut down when the pressure drop of reactor a rose to 0.7 MPa. The calculated operating time was 7000 hours.

[0149] Comparative Example 2

[0150] This comparative example provides a method for grading a hydrogenation catalyst. This method utilizes four 300 ml fixed-bed downflow reactors connected in series. The four reactors are named reactor a, reactor b, reactor c, and reactor d from front to back. The four hydrogenation reactors are divided into a bottom packing zone and a reaction zone above the packing zone. The packing zones of reactors a, b, c, and d are all packed sequentially from bottom to top. and Each of the ceramic balls (inert alumina ceramic balls) contains 2 ml. The main catalyst (i.e., the hydrogenation protection catalyst, the hydrogenation demetallization catalyst, the hydrogenation desulfurization catalyst, and the hydrogenation decarbonization catalyst) is packed in the same way as in Example 2.

[0151] The hydrogenation catalyst gradation method was used to process residue feedstock B, and the hydrogenation process conditions for residue feedstock B were the same as in Example 2.

[0152] The pressure drop of each reactor was 0.18 MPa at the beginning of operation. The reactor was shut down when the pressure drop of reactor d rose to 0.7 MPa. The calculated operating time was 8000 hours.

[0153] Comparative Example 3

[0154] This comparative example provides a method for grading a hydrogenation catalyst. This method is the same as the main catalyst loading method in Example 1, except that in reactors a, b, c, and d, 2 ml each of a 12 mm, 6 mm, and 3 mm equivalent diameter char agent is sequentially loaded from bottom to top. This char agent is the same as that used in Example 1.

[0155] The hydrogenation catalyst gradation method was used to process residue oil feedstock A, and the hydrogenation process conditions for residue oil were the same as in Example 1.

[0156] The pressure drop of each reactor was 0.18 MPa at the beginning of operation. The reactor was shut down when the pressure drop of reactor a rose to 0.7 MPa. The calculated operating time was 10,000 hours.

[0157] Comparative Example 4

[0158] This comparative example provides a method for grading a hydrogenation catalyst. This method is the same as the main catalyst loading method in Example 1, except that in reactors a, b, c, and d, 2 ml each of a metal-containing agent with equivalent diameters of 12 mm, 6 mm, and 3 mm are sequentially loaded from bottom to top. This metal-containing agent is the same as that used in Example 1.

[0159] The hydrogenation catalyst gradation method was used to process residue oil feedstock A, and the hydrogenation process conditions for residue oil were the same as in Example 1.

[0160] The pressure drop of each reactor was 0.18 MPa in the initial stage of operation. The reactor was shut down when the pressure drop of reactor a rose to 0.7 MPa. The calculated operating time was 11,000 hours.

[0161] Comparative Example 5

[0162] This comparative example provides a method for grading a hydrogenation catalyst. This method is essentially the same as that of Example 1, except that the pore volumes of the first and second alumina are lower than those in Example 1. However, the preparation methods of the metal-containing agent and the carbon-containing agent, the active components and their contents, and other physical properties are the same as in Example 1. Specifically, the first alumina contains mesopores of 5–20 nm and macropores of 100–500 nm, with a mesopore volume of 0.54 cm³. 3 / g, the pore size exhibits a bimodal distribution. The second alumina contains only mesopores, with mesopores of 5–15 nm accounting for 99% of the total mesopore volume, and the total mesopore volume is 0.44 cm³. 3 / g.

[0163] The hydrogenation catalyst gradation method was used to process residue oil feedstock A, and the hydrogenation process conditions for residue oil were the same as in Example 1.

[0164] The pressure drop of each reactor was 0.18 MPa at the beginning of operation. The reactor was shut down when the pressure drop of reactor a rose to 0.7 MPa. The calculated operating time was 10,600 hours.

[0165] Comparative Example 6

[0166] This comparative example provides a method for grading a hydrogenation catalyst. This method is the same as the main catalyst loading method in Example 1, except that: in reactors a, b, and c, 2 ml each of a carbon-containing agent with equivalent diameters of 12 mm, 6 mm, and 3 mm are sequentially loaded from bottom to top; and in reactor d, 2 ml each of a metal-containing agent with equivalent diameters of 12 mm, 6 mm, and 3 mm are sequentially loaded from bottom to top. The carbon-containing agent and the metal-containing agent are the same as those in Example 1.

[0167] The hydrogenation catalyst gradation method was used to process residue oil feedstock A, and the hydrogenation process conditions for residue oil were the same as in Example 1.

[0168] The pressure drop of each reactor was 0.18 MPa at the beginning of operation. The reactor was shut down when the pressure drop of reactor a rose to 0.7 MPa. The calculated operating time was 10,500 hours.

[0169] The properties of the hydrotreated residue oils provided by Comparative Examples 1 to 6 are shown in Table 2.

[0170] Table 2 Properties of Hydrogenated Residue Oils from Comparative Examples 1–6

[0171]

[0172]

[0173] The operating results of Examples 1-2 and Comparative Examples 1-2 show that, when producing hydrotreated residue oil with the same properties, the hydrotreating catalyst gradation method of the present invention can improve the operating time of the residue oil hydrotreating unit for both residue oil feedstocks A and B.

[0174] The operational results of Examples 1 and Comparative Examples 3-6 show that, when producing hydrotreated residue oil with the same properties, the metal-containing agent and carbon-containing agent of this invention, when packed in the bottom packing area of ​​the reactor, exhibit a synergistic effect, significantly extending the operating time. Conversely, using either the metal-containing agent or the carbon-containing agent alone in the bottom packing area of ​​the reactor, changing the packing order of the metal-containing agent and carbon-containing agent in the reactor, or using a metal-containing agent or carbon-containing agent with lower mesoporous volume in the bottom packing area of ​​the reactor, all reduce the overall operating cycle of the unit.

Claims

1. A method for grading a hydrotreating catalyst to extend the operating cycle of a residue hydrotreating unit, comprising: The four hydrogenation reactors connected in series are divided into a bottom filling zone and a reaction zone above the filling zone. Metal-containing agents are filled in the filling zone of one or more hydrogenation reactors in the front section of the four hydrogenation reactors connected in series, and carbon-containing agents are filled in the filling zone of one or more hydrogenation reactors in the rear section. All four hydrogenation reactors connected in series are filled with either metal-containing agents or carbon-containing agents. The reaction zones of four hydrogenation reactors connected in series constitute a total reaction zone, in which hydrogenation protection catalyst, hydrogenation demetallization catalyst, hydrogenation desulfurization catalyst and hydrogenation decarbonization catalyst are sequentially packed along the flow direction. The metal-containing agent includes at least a first alumina, which is an alumina containing mesopores and macropores; The residual carbon agent includes at least a second alumina, which is alumina containing only mesoporous structures.

2. The hydrogenation catalyst gradation method according to claim 1, wherein, The reaction zones of one or more hydrogenation reactors in the front section are sequentially filled with one or more of the following along the flow direction: a hydrogenation protection catalyst, a hydrogenation demetallization catalyst, and a hydrogenation desulfurization catalyst. The reaction zones of one or more hydrogenation reactors in the rear section are sequentially filled with one or more of the following along the flow direction: a hydrogenation demetallization catalyst, a hydrogenation desulfurization catalyst, and a hydrogenation decarbonization catalyst.

3. The method for grading hydrogenation catalysts according to claim 1, wherein, The metal-containing agent includes three equivalent diameters: fine, medium, and coarse. The equivalent diameter of the fine metal-containing agent is 2.5~3.5mm, the equivalent diameter of the medium metal-containing agent is 5.5~6.5mm, and the equivalent diameter of the coarse metal-containing agent is 11.5~12.5mm.

4. The hydrogenation catalyst gradation method according to claim 3, wherein, The loading method of the metal-containing agent is as follows: coarse, medium and fine equivalent diameter metal-containing agents are loaded sequentially from bottom to top in the loading zone of the hydrogenation reactor.

5. The hydrogenation catalyst gradation method according to claim 4, wherein, The loading method of the metal-containing agent is as follows: the crude metal-containing agent is loaded above the outlet collector of the hydrogenation reactor; the bed volume of the neutralized fine metal-containing agent is the same as the bed volume of the crude metal-containing agent.

6. The method for grading hydrogenation catalysts according to claim 1, wherein, The loading amount of the metal-containing agent in a hydrogenation reactor is 0.5% to 3.0% of the volume of a hydrogenation reactor.

7. The method for grading hydrogenation catalysts according to claim 1, wherein, The charring agent includes three equivalent diameters: fine, medium, and coarse. The equivalent diameter of the fine charring agent is 2.5~3.5mm, the equivalent diameter of the medium charring agent is 5.5~6.5mm, and the equivalent diameter of the coarse charring agent is 11.5~12.5mm.

8. The method for grading hydrogenation catalysts according to claim 7, wherein, The loading method of the residual carbon agent is as follows: coarse, medium and fine equivalent diameters of residual carbon agent are loaded sequentially from bottom to top in the loading area of ​​the hydrogenation reactor.

9. The method for grading hydrogenation catalysts according to claim 8, wherein, The loading method of the residual carbon agent is as follows: the coarse residual carbon agent is loaded above the outlet collector of the hydrogenation reactor; the bed volume of the neutralized fine residual carbon agent is the same as the bed volume of the coarse residual carbon agent.

10. The method for grading a hydrogenation catalyst according to claim 1, wherein, The loading amount of the residual carbon agent in a hydrogenation reactor is 0.5% to 3.0% of the volume of a hydrogenation reactor.

11. The method for grading hydrogenation catalysts according to claim 1, wherein, The first alumina comprises mesopores of 5-20 nm and macropores of 100-500 nm, with a mesopore volume of 0.60 cm³. 3 Above / g, the pore size exhibits a bimodal distribution.

12. The method for grading hydrogenation catalysts according to claim 1, wherein, The metal-coating agent further includes a first active component loaded on the first alumina; the first active component includes a first main active component and a first auxiliary active component, the first main active component includes molybdenum oxide and / or tungsten oxide, and the first auxiliary active component includes nickel oxide and / or cobalt oxide; based on the total weight of the metal-coating agent as 100%, the total loading of the first active component is 5% to 15%.

13. The method for grading a hydrogenation catalyst according to claim 12, wherein, The first alumina also contains one or more of the elements boron, germanium, zirconium, and phosphorus.

14. The method for grading a hydrogenation catalyst according to claim 12, wherein, The first primary active component is molybdenum oxide, and the first secondary active component is nickel oxide.

15. The method for grading a hydrogenation catalyst according to claim 12, wherein, Based on the total weight of the metal-containing agent as 100%, the loading of the first main active component is 6% to 9%, and the loading of the first auxiliary active component is 1% to 3%.

16. The method for grading hydrogenation catalysts according to claim 1, wherein, The bulk density of the metal-containing agent is 0.20~0.60 g / cm³. 3 Specific surface area is 100~160m² 2 / g.

17. The method for grading a hydrogenation catalyst according to claim 1, wherein, In the second alumina, the pore volume of mesopores with a pore size of 5~15 nm accounts for 85%~95% of the total mesopore volume, and the total mesopore volume is 0.50 cm³. 3 / g or more.

18. The method for grading a hydrogenation catalyst according to claim 1, wherein, The carbonizing agent further includes a second active component loaded on the second alumina; the second active component includes a second main active component and a second auxiliary active component, the second main active component includes molybdenum oxide and / or tungsten oxide, and the second auxiliary active component includes nickel oxide and / or cobalt oxide; based on the total weight of the carbonizing agent as 100%, the total loading of the second active component is 10% to 25%.

19. The method for grading a hydrogenation catalyst according to claim 18, wherein, The second alumina also contains one or more of the elements boron, germanium, zirconium, and phosphorus.

20. The method for grading a hydrogenation catalyst according to claim 18, wherein, The second main active component is molybdenum oxide, and the second auxiliary active component is nickel oxide.

21. The method for grading a hydrogenation catalyst according to claim 18, wherein, Based on the total weight of the activated carbon agent as 100%, the loading of the second main active component is 12%~15%, and the loading of the second auxiliary active component is 2%~4%.

22. The method for grading hydrogenation catalysts according to claim 1, wherein, The bulk density of the residual char agent is 0.40~0.75 g / cm³. 3 Specific surface area is 150~250m² 2 / g.

23. The method for grading hydrogenation catalysts according to claim 1, wherein, When the Ni+V content in the residue feedstock is ≤40μg / g, the metal-containing agent is loaded in the filling zone of the first hydrotreating reactor along the flow direction, and the carbon-containing agent is loaded in the filling zones of the second, third and fourth hydrotreating reactors. When the Ni+V content in the residue feedstock is >40μg / g and ≤70μg / g, the metal-containing agent is filled in the filling zone of the first and second hydrotreating reactors along the flow direction, and the carbon-containing agent is filled in the filling zone of the third and fourth hydrotreating reactors. When the Ni+V content in the residue feedstock is >70μg / g and ≤100μg / g, the metal-containing agent is loaded into the loading zones of the first, second, and third hydrotreating reactors along the flow direction, and the carbon-containing agent is loaded into the loading zone of the fourth hydrotreating reactor.

24. The method for grading hydrogenation catalysts according to claim 1, wherein, The hydrogenation reactor is a fixed-bed downflow reactor.

25. A method for hydrotreating residual oil, comprising: exist Under hydrotreating reaction conditions, residual oil feedstock and hydrogen are sequentially passed through four hydrotreating reactors connected in series, and the hydrogen is reacted with the catalyst packed in the hydrotreating reactors according to the hydrotreating catalyst gradation method for extending the operating cycle of the residual oil hydrotreating unit as described in any one of claims 1-24, to obtain the hydrotreating product.

26. The method for hydrotreating residual oil according to claim 25, wherein, The residue feedstock includes one or a combination of several of the following: atmospheric residue, vacuum residue, deasphalted oil, coal tar, and coal liquefaction heavy oil.

27. The method for hydrotreating residual oil according to claim 25, wherein, The residual oil feedstock has an S content of less than 4.5% by weight, an MCR of less than 18% by weight, and a Ni+V content of less than 100 μg / g.

28. The method for hydrotreating residual oil according to claim 25, wherein, The hydrogenation reaction conditions include: a hydrogen partial pressure of 10.0 MPa to 18.0 MPa, a hydrogen-to-oil volume ratio of 200 to 2000, and a liquid hourly space velocity of 0.10 to 1.0 h⁻¹. -1 The reaction temperature of the first hydrogenation reactor is 310~420℃, and the reaction temperature of the other hydrogenation reactors is 300~420℃.

29. The method for hydrotreating residual oil according to claim 28, wherein, The hydrogenation reaction conditions include: a hydrogen partial pressure of 13.0 MPa to 15.0 MPa, a hydrogen-to-oil volume ratio of 420 to 1500, and a liquid hourly space velocity of 0.14 to 0.45 h⁻¹. -1 The reaction temperature of the first hydrogenation reactor is 360~420℃, and the reaction temperature of the other hydrogenation reactors is 315~410℃.

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