A two-stage hydrocracking method

Abstract

The present invention relates to the technical field of heavy and low-quality wax oil processing, and discloses a two-stage hydrocracking method. The method comprises: introducing heavy and low-quality wax oil into a hydrorefining reaction zone I filled with a hydrorefining catalyst I to perform a first reaction to obtain a reaction effluent I; introducing the reaction effluent I into a hydrorefining reaction zone II filled with a hydrorefining catalyst II to perform a second reaction to obtain a reaction effluent II; introducing the reaction effluent II into a hydrocracking reaction zone filled with a hydrocracking catalyst to perform a third reaction to obtain a reaction effluent III; and separating the reaction effluent III to obtain a light naphtha fraction, a heavy naphtha fraction, an intermediate distillate, and a tail oil fraction. The method provided by the present invention can convert heavy and low-quality wax oil raw materials into high-quality chemical raw materials and clean fuels.

Description

Technical Field

[0001] The present invention relates to the technical field of heavy and inferior wax oil processing, and in particular to a two-stage hydrocracking method. Background Art

[0002] In recent years, domestic demand for automotive diesel among refined oil products has shrunk, while gasoline consumption has slowed. However, market demand for chemical raw materials, such as olefins and aromatics, has grown annually. Consequently, the transition from refining to chemical production is a key development direction. Heavy naphtha, a hydrocracking product, can be used as a feedstock for reforming units to produce aromatics, while tail oil can be used as a feedstock for catalytic cracking units to produce products such as ethylene and propylene. Furthermore, as crude oil production increases annually, the supply of high-quality and conventional crude oil decreases and its price rises, while the supply of heavy and low-quality crude oil increases annually and its price remains relatively low. However, the processing of heavy and low-quality crude oil is difficult and costly, and existing hydrocracking unit process conditions are insufficient to meet the requirements for its advanced processing.

[0003] Therefore, developing a method to directly process cheap and abundant heavy and inferior crude oil to produce reforming materials and high-quality tail oil that can be used as catalytic cracking raw materials has important practical significance for the chemical transformation of refineries and the enhancement of product value.

[0004] To meet the processing needs of heavy and inferior crude oil, delayed coking technology for lightening heavy oil, as well as slurry bed, ebullating bed, and suspension bed heavy oil hydrocracking technologies have been further developed in recent years. However, heavy oil delayed coking, slurry bed, ebullating bed, and suspension bed heavy oil hydrocracking technologies will produce a considerable proportion of wax oil fractions or heavy distillate oils during the process of lightening residual oil or heavy oil. Compared with the wax oil raw materials obtained by conventional crude oil fractionation, the heavy and inferior wax oil fractions or wide-fraction heavy and inferior wax oils obtained by lightening heavy and inferior crude oil have the characteristics of high density, high dry point, high sulfur content, high nitrogen content, and high carbon residue value. The density at 20°C is about 0.94g / cm 3 -0.99g / cm 3 The distillation dry point is about 600℃-720℃, the aromatic content is about 60%-85%, the sulfur content is about 1.5%-3.5%, the nitrogen content is about 1800μg / g-5000μg / g, the residual carbon value is about 1.5%-5.0%, etc. It is difficult to realize the conversion of heavy and inferior wax oil raw materials into light products and high-value products under the existing hydrocracking technology.

[0005] CN104611051A and CN103102957A disclose a two-stage hydrocracking method for high-drying-point heavy distillate oil. This method uses a two-stage denitrogenation method to process heavy straight-run wax oil raw materials with low nitrogen content but complex nitrogen-containing compound structures to produce conventional hydrocracking products.

[0006] CN104611053A discloses a high-drying-point raw material hydrocracking process, which adopts a two-stage denitrification method and arranges a gas-liquid countercurrent contact reaction zone and a gas-liquid separation zone in one stage to realize the processing of heavy and inferior deep-drawn wax oil raw materials with a final distillation point of about 580°C-620°C to produce chemical raw materials and conventional clean fuel oil.

[0007] CN1940030A discloses a two-stage hydrocracking method for producing more diesel from high-nitrogen heavy crude oil. The method realizes the conversion of high-nitrogen heavy low-quality raw materials into high-quality diesel products by partitioning the feed and setting a hot flash tank between the first refining stage and the second refining stage.

[0008] CN103059944A discloses a hydrocracking process for processing inferior raw materials. The method adopts a two-stage hydrocracking process equipped with two fractionation units to convert inferior raw oil with a nitrogen content greater than 2000 μg / g and a final distillation point of approximately 450°C-620°C into chemical raw materials and conventional clean fuel oil.

[0009] CN103443251A discloses a hydrocracking method with feed bottom logistics treatment, which realizes the conversion of heavy and inferior raw materials by adopting a combined process of adsorption denitrogenation and removal of polynuclear aromatics and hydrocracking.

[0010] CN104560169A discloses a hydrocracking method for producing heavy naphtha from a high-nitrogen feedstock. The method realizes the conversion of the high-nitrogen feedstock into a heavy naphtha product by setting a second tail oil fraction conversion reaction zone.

[0011] CN104611010A and CN104611016A disclose a two-stage hydrocracking method for high-drying-point raw materials. This method realizes the conversion of heavy and low-quality raw materials with a final distillation point of 580°C-620°C into conventional clean oil products and chemical raw materials by setting up a gas-liquid separation method in the second-stage refining reaction zone equipped with a bulk catalyst.

[0012] CN104611022A discloses a two-stage hydrocracking method for inferior heavy distillate oil. The method achieves the conversion of heavy and inferior raw materials with a nitrogen content of 2000μg / g-15000μg / g and a final distillation point of 470°C-550°C into conventional clean fuels and chemical fuels by loading refined catalysts with different average pore sizes in two-stage hydrorefining reaction zones.

[0013] CN1508232A discloses a full-cycle hydrocracking process, which achieves the conversion of heavy crude oil with a distillation range of 200°C-600°C by adopting a hydrocracking method of first cracking and then refining, and using two or more high-nitrogen-resistant hydrocracking catalysts in the cracking reaction zone.

[0014] However, there are two main problems in the above existing hydrocracking technology:

[0015] On the one hand, the raw materials processed by existing hydrocracking technology are not of low quality and are difficult to match the processing needs of low-quality raw materials; on the other hand, existing hydrocracking products mainly focus on processing conventional raw materials to produce clean fuel oil (diesel and jet fuel) and some chemical raw materials. There is little research on hydrocracking technology that directly processes heavy and low-quality wax oil to produce reforming and high-quality tail oil that can be used as feedstock for catalytic cracking units.

[0016] To this end, the development of hydrocracking technology for directly processing heavy and inferior wax oil raw materials to produce reforming materials and high-quality catalytic cracking raw materials is of great significance to the chemical transformation and product value enhancement of refining enterprises in processing heavy and inferior crude oil. Summary of the Invention

[0017] The purpose of the present invention is to solve the problems of difficulty in converting heavy and low-quality wax oil raw materials and relatively single product routes in the prior art, and to provide a hydrocracking method for converting heavy and low-quality wax oil into high-quality chemical raw materials (reforming materials and catalytic cracking raw materials) and clean fuels.

[0018] To achieve the above objectives, the present invention provides a two-stage hydrocracking method, which is carried out in an apparatus comprising a hydrofining reaction zone and a hydrocracking reaction zone, wherein the hydrofining reaction zone comprises a hydrofining reaction zone I and a hydrofining reaction zone II. The method comprises:

[0019] (1) introducing the heavy low-quality wax oil into the hydrotreating reaction zone I filled with a hydrotreating catalyst I to perform a first reaction to obtain a reaction effluent I; and sequentially performing gas-liquid separation and gas impurity removal on the reaction effluent I to obtain a mixture I1;

[0020] (2) introducing the mixture I1 into the hydrotreating reaction zone II filled with a hydrotreating catalyst II to perform a second reaction to obtain a reaction effluent II;

[0021] (3) introducing the reaction effluent II into the hydrocracking reaction zone filled with a hydrocracking catalyst to perform a third reaction to obtain a reaction effluent III;

[0022] (4) separating the reaction effluent III to obtain a light naphtha fraction, a heavy naphtha fraction, a middle distillate oil, and a tail oil fraction;

[0023] The heavy low-quality wax oil has a 95% distillation temperature of 580° C. to 700° C. according to ASTM D-1160, a nitrogen content of 1800 μg / g to 3500 μg / g, and a sum of two-ring or higher cycloalkanes and two-ring or higher aromatics of 50 wt % to 80 wt %.

[0024] The mixture I1 contains the liquid phase material obtained after the gas-liquid separation and the hydrogen obtained after the gas impurity removal;

[0025] The hydrorefining catalyst I contains a carrier I and an active metal component I supported on the carrier I, and the hydrorefining catalyst II contains a carrier II and an active metal component II supported on the carrier II, and the weight ratio of the content of the active metal component I calculated as oxide to the content of the active metal component II calculated as oxide is 1.55-1.70:1;

[0026] The conditions of the first reaction are controlled so that the desulfurization rate of the heavy low-quality wax oil is 85%-92%, and the total aromatic saturation rate in the reaction effluent I is 10%-25%.

[0027] The present invention introduces heavy and low-quality wax oil into a hydrorefining reaction zone I and a hydrorefining reaction zone II in sequence to carry out a two-stage hydrorefining reaction. The weight ratio of the metal active components contained in the hydrorefining catalyst I and the hydrorefining catalyst II is controlled simultaneously, and the process conditions of the hydrorefining reaction are coordinated to convert the heavy and low-quality wax oil raw material into a high-quality chemical raw material and a clean fuel. DETAILED DESCRIPTION

[0028] The endpoints of the ranges and any values disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0029] In the present invention, the content of two-ring or higher cycloalkanes in the heavy low-quality wax oil = the mass of two-ring or higher cycloalkanes in the heavy low-quality wax oil / the total mass of hydrocarbon groups in the heavy low-quality wax oil × 100%.

[0030] In the present invention, the content of two-ring or higher aromatic hydrocarbons in the heavy low-quality wax oil = the mass of two-ring or higher aromatic hydrocarbons in the heavy low-quality wax oil / the total mass of hydrocarbon groups in the heavy low-quality wax oil × 100%.

[0031] In the present invention, the hydrocarbon family includes alkanes, cycloalkanes and aromatic hydrocarbons, and the alkanes include straight-chain alkanes and branched-chain alkanes.

[0032] In the present invention, the desulfurization rate of heavy low-quality wax oil = (sulfur mass content in heavy low-quality wax oil - sulfur mass content in reaction effluent I) / sulfur mass content in heavy low-quality wax oil × 100%.

[0033] In the present invention, the total aromatic saturation rate in the reaction effluent I = (total aromatic mass content in the heavy inferior wax oil - total aromatic mass content in the reaction effluent I) / total aromatic mass content in the heavy inferior wax oil × 100%.

[0034] In the present invention, the total aromatic saturation rate in the reaction effluent II = (total aromatic mass content in the heavy inferior wax oil - total aromatic mass content in the reaction effluent II) / total aromatic mass content in the heavy inferior wax oil × 100%.

[0035] In the present invention, the 95% distillation temperature refers to the temperature corresponding to the moment when 95 wt% of the substances in the heavy inferior wax oil evaporate.

[0036] In the present invention, the pore size test is carried out with reference to the catalyst pore size distribution calculation method (nitrogen desorption isotherm calculation method) in SH / T 0572-1993, and the pore volume is tested with reference to the zeolite specific surface area and micropore volume determination method in NB / SH / T 0571-2021 catalyst.

[0037] In the present invention, the mesopore area and specific surface area are tested with reference to NB / SH / T 0571-2021 Method for Determining Specific Surface Area and Micropore Volume of Zeolite in Catalysts and GB / T 5816-1995 Method for Determining Surface Area of Catalysts and Adsorbents.

[0038] As described above, the present invention provides a two-stage hydrocracking method, which is carried out in an apparatus comprising a hydrofining reaction zone and a hydrocracking reaction zone, wherein the hydrofining reaction zone comprises a hydrofining reaction zone I and a hydrofining reaction zone II. The method comprises:

[0039] (1) introducing the heavy low-quality wax oil into the hydrotreating reaction zone I filled with a hydrotreating catalyst I to perform a first reaction to obtain a reaction effluent I; and sequentially performing gas-liquid separation and gas impurity removal on the reaction effluent I to obtain a mixture I1;

[0040] (2) introducing the mixture I1 into the hydrotreating reaction zone II filled with a hydrotreating catalyst II to perform a second reaction to obtain a reaction effluent II;

[0041] (3) introducing the reaction effluent II into the hydrocracking reaction zone filled with a hydrocracking catalyst to perform a third reaction to obtain a reaction effluent III;

[0042] (4) separating the reaction effluent III to obtain a light naphtha fraction, a heavy naphtha fraction, a middle distillate oil, and a tail oil fraction;

[0043] The heavy low-quality wax oil has a 95% distillation temperature of 580° C. to 700° C. according to ASTM D-1160, a nitrogen content of 1800 μg / g to 3500 μg / g, and a sum of two-ring or higher cycloalkanes and two-ring or higher aromatics of 50 wt % to 80 wt %.

[0044] The mixture I1 contains the liquid phase material obtained after the gas-liquid separation and the hydrogen obtained after the gas impurity removal;

[0045] The hydrorefining catalyst I contains a carrier I and an active metal component I supported on the carrier I, and the hydrorefining catalyst II contains a carrier II and an active metal component II supported on the carrier II, and the weight ratio of the content of the active metal component I calculated as oxide to the content of the active metal component II calculated as oxide is 1.55-1.70:1;

[0046] The conditions of the first reaction are controlled so that the desulfurization rate of the heavy low-quality wax oil is 85%-92%, and the total aromatic saturation rate in the reaction effluent I is 10%-25%.

[0047] During the course of their research, the inventors of the present invention discovered that by loading different hydrorefining catalysts having active metal component content ratios within a certain range into the hydrorefining catalytic reaction zone I and the hydrorefining catalytic reaction zone II, on the one hand, it is possible to save catalyst activity costs while obtaining higher aromatic hydrocarbon saturation performance, and on the other hand, by reducing the number of hydrogenation active centers in the hydrorefining catalytic reaction zone II, the purpose of controlling aromatic hydrocarbon saturation in the hydrorefining catalytic reaction zone II and thus reducing reaction hydrogen consumption is achieved.

[0048] At the same time, the inventors of the present invention also discovered during the research process that, after carrying out the desulfurization reaction and light aromatic saturation in the hydrorefining catalytic reaction zone I, on the one hand, the competitive adsorption reaction of aromatic molecules on the metal active center of the hydrorefining catalyst I by removing hydrogen sulfide, ammonia, etc. in the reaction system can be carried out, thereby making the aromatic saturation in the hydrorefining catalytic reaction zone II and the ring-opening cracking in the cracking reaction zone more efficient; in addition, by retaining a certain content of sulfur-containing compounds, a certain concentration of hydrogen sulfide can be provided for the sulfurized active centers of the catalysts in the hydrorefining catalytic reaction zone II and the hydrocracking reaction zone, thereby ensuring the stability of the active centers of the catalysts.

[0049] Preferably, in step (2), the conditions of the second reaction are controlled so that the total aromatic saturation rate in the reaction effluent II is 55%-85%. The inventors of the present invention have found that increasing the aromatic saturation rate in the hydrotreating reaction zone II and converting aromatic molecules into cycloalkanes or monocyclic aromatic molecules containing cycloalkanes can not only enable the hydrocracking reaction zone to highly selectively convert polycyclic cycloalkanes or aromatic molecules containing cycloalkanes into reforming materials at a relatively low cracking reaction load, but also retain paraffins and monocyclic alkanes or aromatic molecules as high-quality catalytic cracking unit feedstocks.

[0050] Preferably, in step (3), the conditions of the third reaction are controlled so that the sum of the yields of the light naphtha fraction and the heavy naphtha fraction is 40%-70%. The inventors of the present invention have found that under this preferred embodiment, high aromatic potential heavy naphtha, qualified diesel, and high-quality tail oil with high product selectivity can be obtained.

[0051] Preferably, in step (1) and step (2), the loading volume ratio of the hydrorefining catalyst I to the hydrorefining catalyst II is 0.25-4:1. The inventors of the present invention have discovered that by controlling the loading volume ratio of the hydrorefining catalyst I to the hydrorefining catalyst II within the aforementioned range, it is possible to effectively increase the aromatics saturation rate while reducing the catalyst dosage, thereby reducing the investment cost of the reactor and the cost of using the catalyst.

[0052] Preferably, in step (4), the initial boiling point of the tail oil fraction is 340°C-360°C.

[0053] Preferably, in step (1), the loading volume content of the hydrotreating catalyst I is 60%-90% based on the total volume of the catalyst in the hydrotreating reaction zone I. The inventors of the present invention have found that under this preferred embodiment, high aromatic potential heavy naphtha, qualified diesel, and high-quality tail oil with high product selectivity can be obtained at a lower cost.

[0054] According to a preferred embodiment, in step (1), in the hydrorefining reaction zone I, according to the direction of flow of the liquid phase material, a hydrogenation protection catalyst and a hydrodemetallization catalyst are sequentially loaded upstream of the hydrorefining catalyst I.

[0055] Further preferably, in step (1), based on the total volume of the catalyst in the hydrorefining reaction zone I, the loading volume content of the hydrogenation protection catalyst is 5%-25%, and the loading volume content of the hydrodemetallization catalyst is 5%-15%.

[0056] According to another preferred embodiment, in step (1), in the hydrorefining catalyst I, the carrier I is alumina or silica-alumina, and the active metal component I contains at least one metal element selected from Group VIII non-precious metal elements and Group VIB non-precious metal elements; and the content of the active metal component I calculated as oxide is 35 wt% to 55 wt% based on the total weight of the hydrorefining catalyst I.

[0057] More preferably, in step (1), in the hydrotreating catalyst I, the Group VIII non-noble metal element is selected from at least one of nickel and cobalt, and the Group VIB non-noble metal element is a combination of molybdenum and tungsten.

[0058] Further preferably, in step (1), based on the total weight of the hydrotreating catalyst I, the content of the non-noble metal elements of Group VIII calculated as oxides is 1 wt%-15 wt%, and the content of the non-noble metal elements of Group VIB calculated as oxides is 5 wt%-40 wt%.

[0059] Furthermore, in step (1), in the hydrorefining catalyst I, in the carrier I, the ratio of the total volume of pores with a pore diameter greater than or equal to 10 nm to the total pore volume is 0.6-0.8:1. The total pore volume is the total pore volume of the carrier I.

[0060] Particularly preferably, in step (1), in the hydrorefining catalyst I, in the carrier I, the ratio of the mesopore area to the total specific surface area is 0.3-0.7:1. The mesopore area is also the surface area. The total specific surface area is the total specific surface area of the carrier I.

[0061] Preferably, in step (2), in the hydrorefining catalyst II, the carrier II is alumina or silica-alumina, and the active metal component II contains at least one metal element selected from Group VIII non-precious metal elements and Group VIB non-precious metal elements; and the content of the active metal component II calculated as oxide is 35wt%-55wt% based on the total weight of the hydrorefining catalyst II.

[0062] Further preferably, in step (2), in the hydrotreating catalyst II, the Group VIII non-noble metal element is selected from at least one of nickel and cobalt, and the Group VIB non-noble metal element is selected from at least one of molybdenum and tungsten.

[0063] More preferably, based on the total weight of the hydrorefining catalyst II, the content of the Group VIII non-noble metal elements is 1 wt%-15 wt%, and the content of the Group VIB non-noble metal elements in terms of oxides is 5 wt%-40 wt%.

[0064] Preferably, in step (3), the hydrocracking catalyst contains a carrier III and an active metal component III supported on the carrier III, the carrier III contains a heat-resistant inorganic oxide and an acidic component, the heat-resistant inorganic oxide is selected from at least one of silicon oxide and aluminum oxide, and the acidic component contains a Y-type molecular sieve; the active metal component III contains at least two metal elements selected from Group VIB metal elements and Group VIII metal elements; and based on the total weight of the hydrocracking catalyst, the content of the Group VIB metal element calculated as oxide is 15wt%-33wt%, and / or the content of the Group VIII metal element calculated as oxide is 2wt%-8wt%.

[0065] More preferably, based on the total weight of the carrier III, the content of the acidic component is 40 wt%-75 wt%.

[0066] Particularly preferably, the content of the Y-type molecular sieve is 60 wt%-100 wt% based on the total weight of the acidic components. The inventors of the present invention have found that under this preferred condition, heavy low-quality wax oil feedstock can be cracked and converted into heavy naphtha efficiently and selectively.

[0067] Preferably, in step (1), the hydrogenation protected catalyst contains a carrier IV and / or an active metal component IV supported on the carrier IV, the carrier IV is selected from at least one of aluminum oxide, silicon oxide and titanium oxide, and the active metal component IV contains at least one metal element selected from Group VIII non-noble metal elements and Group VIB metal elements; and the content of the active metal component IV calculated as oxide is 0.1 wt% to 15 wt% based on the total weight of the hydrogenation protected catalyst.

[0068] Furthermore, the linear average particle size of the hydrogenation protection catalyst is 0.5 mm to 50.0 mm, and the bulk density is 0.3 g / cm 3 -1.2g / cm 3 , with a specific surface area of 50m 2 / g-300m 2 / g.

[0069] Preferably, in step (1), the hydrodemetallization catalyst contains a carrier V and an active metal component V supported on the carrier V, the carrier V is selected from at least one of aluminum oxide, silicon oxide and titanium oxide, and the active metal component V contains at least one metal element selected from Group VIII non-noble metal elements and Group VIB metal elements; and the content of the active metal component V calculated as oxide is 3 wt% to 30 wt% based on the total weight of the hydrodemetallization catalyst.

[0070] More preferably, the linear average particle size of the hydrodemetallization catalyst is 0.2 mm to 6.0 mm, and the bulk density is 0.3 g / cm 3 -0.8g / cm 3 , with a specific surface area of 100m 2 / g-250m 2 / g.

[0071] According to a preferred embodiment, in step (1) and step (2), the conditions of the first reaction and the second reaction independently include: a hydrogen partial pressure of 10.0 MPa-20.0 MPa, a reaction temperature of 280°C-400°C, a liquid hourly space velocity of 0.5 h -1 -6h -1 , the hydrogen-to-oil volume ratio is 300-2000.

[0072] According to another preferred embodiment, in step (3), the conditions of the third reaction include: hydrogen partial pressure of 6.0MPa-20.0MPa, reaction temperature of 290℃-420℃, liquid hourly space velocity of 0.3h -1 -5h -1 , the hydrogen-to-oil volume ratio is 300-2000.

[0073] Preferably, the heavy low-quality wax oil is selected from at least one of straight-run wax oil and secondary processed oil.

[0074] Further preferably, the straight-run wax oil is selected from at least one of second-line wax oil, third-line wax oil, fourth-line wax oil and fifth-line wax oil; the secondary processing oil is selected from at least one of slurry bed wax oil, boiling bed wax oil and deasphalted oil.

[0075] The present invention will be described in detail below through examples.

[0076] In the following examples, unless otherwise specified, all raw materials used were commercially available.

[0077] In the following examples, the preparation method of purified CAT1 is as follows:

[0078] Weigh 1000g of pseudo-boehmite (purchased from Sinopec Catalyst Changling Branch, with a dry basis of 0.73 and a specific surface area of 300m 2 / g, pore volume of 0.97 mL / g), extruded into clover-shaped strips with a circumscribed circle diameter of 1.6 mm, dried at 110 ° C for 8 h, ventilated with air, heated to 600 ° C at a rate of 3 ° C / min, and calcined for 3 h to prepare alumina support I1;

[0079] 200 g of carrier I1 was placed in a polytetrafluoroethylene-lined self-pressurized sealed autoclave, 100 g of deionized water was added and sealed, and the autoclave was subjected to a constant temperature hydrothermal treatment at 90°C for 12 h, followed by filtration. The obtained solid was dried at 120°C for 4 h to obtain carrier I2;

[0080] At room temperature (25±2°C), 200g of carrier I2 was placed in 242mL of an aqueous solution containing 68.5g of ammonium metatungstate, 13.7g of ammonium paramolybdate, 20.1g of basic nickel carbonate and 3.2g of boric acid, and the mixture was immersed for 1h and filtered. The obtained solid was dried at 120°C for 6h and then calcined at 400°C for 3h to obtain carrier I3; carrier I3 was placed in 242mL of an aqueous solution containing 23.14g of citric acid and immersed for 1h and filtered. The obtained solid was dried at 120°C for 3h to obtain refined CAT1.

[0081] In the following example,

[0082] The yield of light naphtha fraction is defined as: the mass of the separated light naphtha fraction (<65°C) / the mass of the heavy low-quality wax oil × 100%;

[0083] The yield of heavy naphtha fraction is defined as: the mass of the separated heavy naphtha fraction (initial boiling point is 65°C, final boiling point is 165°C-175°C) / the mass of heavy inferior wax oil × 100%;

[0084] The yield of diesel fraction is defined as: the weight of the separated middle distillate oil (175°C - T1°C) / the weight of the heavy low-quality wax oil × 100%; T1 is the initial boiling point of the tail oil fraction;

[0085] The yield of the tail oil fraction = the mass of the separated tail oil fraction / the mass of the heavy and inferior wax oil × 100%.

[0086] raw material:

[0087] Hydrorefining catalyst:

[0088] Refined CAT1: Carrier I is alumina, and as oxides, the content of molybdenum is 5.6wt%, the content of tungsten is 32wt%, and the content of nickel is 6.3wt%. The ratio of the total volume of pores with a pore diameter greater than or equal to 10nm in carrier I to the total pore volume is 0.693:1. The surface area of carrier I is 71.68m2 / g, and the ratio of the total specific surface area is 0.3106:1;

[0089] Refined CAT2-1: Brand RN-32V, carrier II is alumina, calculated as oxide, the tungsten content is 23.0wt%, the molybdenum content is 2.3wt%, and the nickel content is 2.4wt%;

[0090] Refined CAT2-2: Brand RN-410B, carrier II is alumina, calculated as oxide, the molybdenum content is 26.5wt%, and the nickel content is 4.2wt%;

[0091] Hydrogenation protection catalyst:

[0092] Protection CAT3: Brand is RG-200, carrier IV is alumina, does not contain active metal components, linear average particle size is 16mm, specific surface area is 100m 2 / g, bulk density is 0.65g / cm 3 ;

[0093] Protective CAT4: Brand is RG-201, carrier IV is alumina, calculated as oxide, the molybdenum content is 1.2wt%, the nickel content is 0.3wt%, the linear average particle size is 10mm, and the specific surface area is 95m 2 / g bulk density is 0.56g / cm 3 ;

[0094] Protection CAT5: Brand is RG-30A, carrier IV is alumina, calculated as oxide, the molybdenum content is 2.5wt%, the nickel content is 0.5wt%, the linear average particle size is 6.0mm, and the specific surface area is 90m 2 / g, bulk density is 0.48g / cm;

[0095] Protective CAT6: Brand is RG-30B, carrier IV is alumina, calculated as oxide, the molybdenum content is 5.5wt%, the nickel content is 1.0wt%, the linear average particle size is 3.0mm, and the specific surface area is 90.0m 2 / g, bulk density is 0.50g / cm 3 ;

[0096] Hydrodemetallization catalyst:

[0097] Demetallized CAT7: The brand is RAM-100, the carrier V is alumina, the content of molybdenum is 7.5wt%, the content of nickel is 1.3wt%, the linear average particle size is 1.8mm, and the specific surface area is 160m 2 / g, bulk density is 0.45g / cm 3 ;

[0098] Hydrocracking catalyst:

[0099] Cracking CAT8: RHC-210, with a tungsten content of 27.0 wt% and a nickel content of 2.7 wt% based on oxides, with the balance being carrier III; an acidic component content of 65 wt% based on the total weight of carrier III, with the balance being alumina; and a Y-type molecular sieve content of 100 wt% based on the total weight of the acidic components;

[0100] Cracking CAT9: The brand is RHC-133. Calculated as oxides, the tungsten content is 24.5wt%, the nickel content is 6.5wt%, and the balance is carrier III; calculated based on the total weight of carrier III, the acidic component content is 20wt%, and the balance is alumina; calculated based on the total weight of the acidic components, the Y-type molecular sieve content is 50wt%, and the balance is amorphous silica-alumina.

[0101] In the following examples, the properties of the heavy low-quality wax oil used are shown in Table 1.

[0102] Table 1

[0103]

[0104]

[0105] Example 1

[0106] (1) introducing the heavy low-quality wax oil into the hydrotreating reaction zone I filled with a hydrotreating catalyst I to perform a first reaction to obtain a reaction effluent I; and sequentially performing gas-liquid separation and gas impurity removal on the reaction effluent I to obtain a mixture I1;

[0107] (2) introducing the mixture I1 into the hydrotreating reaction zone II filled with a hydrotreating catalyst II to perform a second reaction to obtain a reaction effluent II;

[0108] (3) introducing the reaction effluent II into the hydrocracking reaction zone filled with a hydrocracking catalyst to perform a third reaction to obtain a reaction effluent III;

[0109] (4) separating the reaction effluent III to obtain a light naphtha fraction, a heavy naphtha fraction, a middle distillate oil, and a tail oil fraction;

[0110] The mixture I1 contains the liquid phase material obtained after the gas-liquid separation and the hydrogen obtained after the gas impurity removal;

[0111] The specific process parameters are shown in Table 2, and the yield and property parameters of the product are shown in Table 3.

[0112] Example 2

[0113] This embodiment is carried out in the same manner as in embodiment 1, except that:

[0114] The reaction temperature of the second reaction is 365°C;

[0115] The reaction temperature of the third reaction was 362°C;

[0116] The remaining process parameters are the same as those in Example 1.

[0117] The nitrogen mass fraction in the reaction effluent II in this example is 9 μg·g -1 , the total aromatic saturation rate is 67.24%;

[0118] The total yield of the light naphtha fraction and the heavy naphtha fraction was 41.00%.

[0119] The yield and property parameters of the product are shown in Table 3.

[0120] Example 3

[0121] This embodiment is carried out in the same manner as in embodiment 1, except that:

[0122] The reaction temperature of the second reaction is 365°C;

[0123] The reaction temperature of the third reaction is 366°C;

[0124] The remaining process parameters are the same as those in Example 1.

[0125] The nitrogen mass fraction in the reaction effluent II in this example is 9 μg·g -1 , the total aromatic saturation rate is 67.24%;

[0126] The total yield of the light naphtha fraction and the heavy naphtha fraction was 62.70%.

[0127] The yield and property parameters of the product are shown in Table 3.

[0128] Example 4

[0129] This embodiment is carried out in the same manner as in embodiment 1, except that:

[0130] The reaction temperature of the third reaction is 374°C;

[0131] The remaining process parameters are the same as those in Example 1.

[0132] In this embodiment, the total yield of the light naphtha fraction and the heavy naphtha fraction is 80.00%.

[0133] The yield and property parameters of the product are shown in Table 3.

[0134] Example 5

[0135] This embodiment is carried out in the same manner as in embodiment 1, except that:

[0136] The reaction temperature of the third reaction is 392°C;

[0137] In the hydrocracking reaction zone, an equal volume of cracking CAT8 is replaced by cracking CAT9.

[0138] The remaining process parameters are the same as those in Example 1.

[0139] In this embodiment, the total yield of the light naphtha fraction and the heavy naphtha fraction is 40.00%.

[0140] The yield and property parameters of the product are shown in Table 3.

[0141] Example 6

[0142] This embodiment is carried out in the same manner as in embodiment 1, except that:

[0143] In the hydrofining reaction zone I, the loading amount of each catalyst was adjusted to: 3+4+7+8+25+53;

[0144] The reaction temperature of the third reaction was 392°C.

[0145] The remaining process parameters are the same as those in Example 1.

[0146] In this embodiment, the total aromatic saturation rate in the reaction effluent I is 23.5%, and the desulfurization rate is 90.5%;

[0147] The nitrogen mass fraction in the reaction effluent II is 17 μg·g -1 , the total aromatic saturation rate is 58.64%;

[0148] The total yield of the light naphtha fraction and the heavy naphtha fraction was 40.50%.

[0149] The yield and property parameters of the product are shown in Table 3.

[0150] Comparative Example 1

[0151] (1) introducing the heavy low-quality wax oil into the hydrotreating reaction zone I filled with a hydrotreating catalyst I to perform a first reaction to obtain a reaction effluent I;

[0152] (2) introducing the reaction effluent I into the hydrotreating reaction zone II filled with a hydrotreating catalyst II to perform a second reaction to obtain a reaction effluent II;

[0153] (3) introducing the reaction effluent II into the hydrocracking reaction zone filled with a hydrocracking catalyst to perform a third reaction to obtain a reaction effluent III;

[0154] (4) separating the reaction effluent III to obtain a light naphtha fraction, a heavy naphtha fraction, a middle distillate oil, and a tail oil fraction;

[0155] The specific process parameters are shown in Table 2, and the yield and property parameters of the product are shown in Table 3.

[0156] Comparative Example 2

[0157] This comparative example was carried out in the same manner as in Example 1, except that:

[0158] The reaction temperature for the first reaction was 385°C;

[0159] The reaction temperature of the second reaction is 385°C;

[0160] In the hydrofining reaction zone II, an equal volume of refined CAT2-1 was replaced with refined CAT1;

[0161] The loading volume ratio of hydrofining catalyst I to hydrofining catalyst II is 0.2:1;

[0162] The reaction temperature of the third reaction is 387°C;

[0163] The remaining process parameters are the same as those in Example 1.

[0164] In this embodiment, the total aromatic saturation rate in the reaction effluent I is 7.5%, and the desulfurization rate is 63.2%;

[0165] The nitrogen mass fraction in the reaction effluent II is 12 μg·g -1 , the total aromatic saturation rate is 53.56%;

[0166] The total yield of the light naphtha fraction and the heavy naphtha fraction was 51.51%.

[0167] The yield and property parameters of the product are shown in Table 3.

[0168] Comparative Example 3

[0169] This comparative example was carried out in the same manner as in Example 1, except that:

[0170] The reaction temperature of the second reaction is 370°C;

[0171] In the hydrofining reaction zone II, an equal volume of refined CAT2-1 was replaced with refined CAT2-2;

[0172] The reaction temperature of the third reaction was 359°C;

[0173] The remaining process parameters are the same as those in Example 1.

[0174] The nitrogen mass fraction in the reaction effluent II in this example is 14 μg·g -1 , the total aromatic saturation rate is 57.34%;

[0175] The total yield of the light naphtha fraction and the heavy naphtha fraction was 40.50%.

[0176] The yield and property parameters of the product are shown in Table 3.

[0177] Comparative Example 4

[0178] This comparative example was carried out in the same manner as in Example 1, except that: in this comparative example: the reaction temperature of the first reaction was 395°C;

[0179] The reaction temperature of the second reaction was 367°C;

[0180] The reaction temperature of the third reaction is 360°C;

[0181] The remaining process parameters are the same as those in Example 1.

[0182] In this example, the total aromatic saturation rate in the reaction effluent I is 27.3%, and the desulfurization rate is 96.2%. The nitrogen mass fraction in the reaction effluent II is 7 μg·g -1 , the total aromatic saturation rate is 70.3%; the sum of the yields of the light naphtha fraction and the heavy naphtha fraction is 43.20%.

[0183] The yield and property parameters of the product are shown in Table 3.

[0184] Comparative Example 5

[0185] This comparative example was carried out in the same manner as in Example 1, except that in this example: the reaction temperature of the first reaction was 380°C;

[0186] The reaction temperature of the second reaction is 365°C;

[0187] In the hydrofining reaction zone II, an equal volume of refined CAT2-1 was replaced with refined CAT1;

[0188] The loading volume ratio of hydrofining catalyst I to hydrofining catalyst II is 2:1;

[0189] The reaction temperature of the third reaction is 363°C;

[0190] The remaining process parameters are the same as those in Example 1.

[0191] In this comparative example, the total aromatic saturation rate in the reaction effluent I was 24.2%, and the desulfurization rate was 91.5%. The nitrogen mass fraction in the reaction effluent II was 10 μg·g -1 , the total aromatic saturation rate is 67.51%; the sum of the yields of light naphtha fraction and heavy naphtha fraction is 53.37%.

[0192] The yield and property parameters of the product are shown in Table 3.

[0193] Comparative Example 6

[0194] This comparative example was carried out in the same manner as in Comparative Example 5, except that in this example: the reaction temperature of the third reaction was 367°C;

[0195] The remaining process parameters are the same as those in Example 1.

[0196] The total yield of the light naphtha fraction and the heavy naphtha fraction was 64.57%.

[0197] The yield and property parameters of the product are shown in Table 3.

[0198] Comparative Example 7

[0199] This comparative example was carried out in the same manner as in Comparative Example 5, except that:

[0200] The reaction temperature of the third reaction is 370°C;

[0201] The remaining process parameters are the same as those in Example 1.

[0202] The total yield of the light naphtha fraction and the heavy naphtha fraction was 69.23%.

[0203] The yield and property parameters of the product are shown in Table 3.

[0204] Table 2

[0205]

[0206]

[0207] Note: 1. Protection CAT3+Protection CAT4+Protection CAT5+Protection CAT6+Demetallization CAT7+Refined CAT1 means that according to the direction of liquid material flow, Protection CAT3, Protection CAT4, Protection CAT5, Protection CAT6, Demetallization CAT7 and Refined CAT1 are loaded in sequence;

[0208] 2. The column of "Packing Volume Ratio" refers to the loading volume ratio of hydrotreating catalyst I to hydrotreating catalyst II.

[0209] Table 3

[0210]

[0211] From the data in Table 2 and Table 3, we can see that:

[0212] In Examples 1 to 6, the desulfurization rate of the heavy low-quality wax oil is controlled within the range of 85%-92%, the total aromatic saturation rate in the reaction effluent I is controlled within the range of 10%-25%, and the weight ratio of the active metal components in the hydrorefining catalyst I and the hydrorefining catalyst II, calculated as oxides, is controlled to be 1.55-1.70:1; the aromatic latent content of the obtained heavy naphtha is not less than 52wt%, which can be used as a high-quality reforming material; the cetane index of the obtained diesel fraction is not less than 48wt%, which can be used as a clean diesel blending component; and the hydrogen content of the obtained tail oil fraction is not less than 13.5wt%, which can meet the raw material feed requirements of a high-quality DCC unit.

[0213] In Example 7, the yields of light naphtha and heavy naphtha were controlled at 80%. Although qualified products were obtained, there were problems such as low tail oil product yield, increased light naphtha product yield, and poor heavy naphtha selectivity.

[0214] In Example 8, a hydrocracking catalyst containing an acidic component, especially a Y-type molecular sieve content of less than 60 wt%, was used. Although qualified products were obtained, the catalyst activity was significantly reduced, requiring a very high operating temperature. This resulted in a mismatch between the operating temperatures of the hydrofinishing reaction zone II and the hydrocracking reaction zone, necessitating additional heating measures and increasing operating costs.

[0215] In Example 9, the loading volume ratio of the hydroprotected catalyst and the hydrodemetallization catalyst in the hydrorefining reaction zone I was increased, so that the loading volume ratio of the hydrorefining catalyst I was less than 60%. Although a product distribution and quality similar to those of Example 1 were obtained under similar reaction conditions, due to the low number of active sites of the hydroprotected catalyst and the hydrodemetallization catalyst, the large loading ratio would result in a significant increase in the reactor volume, thereby increasing the reactor manufacturing cost and the equipment investment cost.

[0216] In Comparative Example 1, the reaction effluent I was not subjected to gas-liquid separation and gas impurity removal. Under the influence of the reaction atmosphere and competitive adsorption, the total aromatic saturation rate of the reaction effluent was still low at only 49.22% under the harsh hydrorefining reaction conditions. This will increase the difficulty of the hydrocracking reaction conversion. -1 Under the condition of cracking reaction temperature of 390℃, the total yield of light naphtha fraction and heavy naphtha is 47.33%. It can be seen that if the method provided by the present invention is not adopted, it is difficult to achieve a large-scale conversion of heavy and inferior wax oil raw materials into chemical raw materials;

[0217] In Comparative Example 2, the loading volume ratio of the hydrorefining catalyst I to the hydrorefining catalyst II was adjusted to 0.2:1. At the harsh reaction temperature of 385°C, the desulfurization rate of the heavy low-quality wax oil was only 63.2%, and the total aromatic saturation rate of the reaction effluent I was only 7.5%. This increased the reaction severity of the hydrorefining reaction zone II. At a reaction temperature of 385°C, the total aromatic saturation rate of the reaction effluent II was only 53.56%, which increased the difficulty of the hydrocracking reaction. The corresponding naphtha fraction yield at a cracking reaction temperature of 387°C was only 51.51%. This not only increased the fuel gas consumption of the reaction process and increased the energy consumption of the device, but also shortened the operating cycle of the catalyst, making the reaction process less economical.

[0218] In Comparative Examples 3 and 5 to 7, hydrorefining catalyst CAT2-2 and hydrorefining catalyst CAT were used to replace hydrorefining catalyst CAT2-1, so that the weight ratio of the content of active metal component I to the content of active metal component II was not 1.55-1.70:1. At the same time, a higher reaction temperature was used in the hydrorefining reaction zone II. Although similar effects to those of the embodiments provided by the present invention were obtained, the diesel yield of the product was high and the heavy naphtha aromatic potential was low, indicating that hydrogen consumption increased during the reaction process, failing to achieve the expected reduction in hydrogen consumption.

[0219] In Comparative Example 4, the reaction temperature in the hydrorefining reaction zone I was increased to 395° C. to increase the total aromatic saturation rate of the reaction effluent I to 27.3%, while maintaining similar reaction conditions in the hydrorefining reaction zone II and the hydrocracking reaction zone. Although a higher yield of high aromatic potential heavy naphtha, qualified diesel, and high-quality tail oil can be obtained, the operating temperature of the hydrorefining reaction zone I is too high, which is not conducive to the long-term operation of the hydrorefining reaction zone I.

[0220] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A two-stage hydrocracking method, characterized in that: The method is carried out in a device containing a hydrofining reaction zone and a hydrocracking reaction zone, wherein the hydrofining reaction zone contains a hydrofining reaction zone I and a hydrofining reaction zone II. The method comprises: (1) introducing the heavy low-quality wax oil into the hydrorefining reaction zone I filled with the hydrorefining catalyst I to carry out a first reaction to obtain a reaction effluent I, and sequentially subjecting the reaction effluent I to gas-liquid separation and gas impurity removal to obtain a mixture I1; (2) introducing the mixture I1 into the hydrotreating reaction zone II filled with a hydrotreating catalyst II to carry out a second reaction to obtain a reaction effluent II; controlling the conditions of the second reaction so that the total aromatic saturation rate in the reaction effluent II is 55%-85%; (3) introducing the reaction effluent II into the hydrocracking reaction zone filled with a hydrocracking catalyst to perform a third reaction to obtain a reaction effluent III; (4) separating the reaction effluent III to obtain a light naphtha fraction, a heavy naphtha fraction, an intermediate distillate oil, and a tail oil fraction; controlling the conditions of the third reaction so that the sum of the yields of the light naphtha fraction and the heavy naphtha fraction is 40%-70%; and the initial boiling point of the tail oil fraction is 340°C-360°C; The heavy low-quality wax oil has a 95% distillation temperature of 580° C. to 700° C. according to ASTM D-1160, a nitrogen content of 1800 μg / g to 3500 μg / g, and a sum of two-ring or higher cycloalkanes and two-ring or higher aromatics of 50 wt % to 80 wt %. The mixture I1 contains the liquid phase material obtained after the gas-liquid separation and the hydrogen obtained after the gas impurity removal; The hydrorefining catalyst I contains a carrier I and an active metal component I supported on the carrier I, and the hydrorefining catalyst II contains a carrier II and an active metal component II supported on the carrier II, and the weight ratio of the content of the active metal component I calculated as oxide to the content of the active metal component II calculated as oxide is 1.55-1.70:1; Controlling the conditions of the first reaction so that the desulfurization rate of the heavy low-quality wax oil is 85%-92%, and the total aromatic saturation rate in the reaction effluent I is 10%-25%; In step (1) and step (2), the loading volume ratio of the hydrotreating catalyst I to the hydrotreating catalyst II is 0.25-4:

1.

2. The method according to claim 1, wherein In step (1), based on the total volume of the catalyst in the hydrotreating reaction zone I, the loading volume content of the hydrotreating catalyst I is 60%-90%.

3. The method according to claim 2, wherein: In step (1), in the hydrorefining reaction zone I, according to the flow direction of the liquid phase material, a hydrogenation protection catalyst and a hydrodemetallization catalyst are sequentially loaded upstream of the hydrorefining catalyst I.

4. The method according to claim 3, wherein: In step (1), based on the total volume of the catalyst in the hydrorefining reaction zone I, the loading volume content of the hydrogenation protection catalyst is 5%-25%, and the loading volume content of the hydrodemetallization catalyst is 5%-15%.

5. The method according to any one of claims 1 to 4, wherein: In step (1), in the hydrorefining catalyst I, the carrier I is alumina or silica-alumina, and the active metal component I contains at least one metal element selected from Group VIII non-precious metal elements and Group VIB non-precious metal elements; and the content of the active metal component I calculated as oxide is 35 wt% to 55 wt% based on the total weight of the hydrorefining catalyst I.

6. The method according to claim 5, wherein: In step (1), in the hydrorefining catalyst I, the Group VIII non-noble metal element is selected from at least one of nickel and cobalt, and the Group VIB non-noble metal element is a combination of molybdenum and tungsten.

7. The method according to claim 6, wherein: In step (1), based on the total weight of the hydrorefining catalyst I, the content of the non-noble metal elements of Group VIII calculated as oxides is 1 wt%-15 wt%, and the content of the non-noble metal elements of Group VIB calculated as oxides is 5 wt%-40 wt%.

8. The method according to claim 5, wherein In step (1), in the hydrorefining catalyst I, in the carrier I, the ratio of the total volume of pores with a pore diameter greater than or equal to 10 nm to the total pore volume is 0.6-0.8:

1.

9. The method according to claim 8, wherein In step (1), in the hydrorefining catalyst I, in the carrier I, the ratio of the mesopore area to the total specific surface area is 0.3-0.7:

1.

10. The method according to any one of claims 1 to 4, wherein: In step (2), in the hydrorefining catalyst II, the carrier II is alumina or silica-alumina, and the active metal component II contains at least one metal element selected from Group VIII non-precious metal elements and Group VIB non-precious metal elements; and the content of the active metal component II calculated as oxide is 35 wt% to 55 wt% based on the total weight of the hydrorefining catalyst II.

11. The method according to claim 10, wherein: In step (2), in the hydrorefining catalyst II, the Group VIII non-noble metal element is selected from at least one of nickel and cobalt, and the Group VIB non-noble metal element is selected from at least one of molybdenum and tungsten.

12. The method according to claim 10, wherein: Based on the total weight of the hydrorefining catalyst II, the content of the Group VIII non-noble metal elements is 1 wt%-15 wt%, and the content of the Group VIB non-noble metal elements calculated as oxides is 5 wt%-40 wt%.

13. The method according to any one of claims 1 to 4, wherein: In step (3), the hydrocracking catalyst contains a carrier III and an active metal component III supported on the carrier III, the carrier III contains a heat-resistant inorganic oxide and an acidic component, the heat-resistant inorganic oxide is selected from at least one of silicon oxide and aluminum oxide, and the acidic component contains a Y-type molecular sieve; the active metal component III contains at least two metal elements selected from Group VIB metal elements and Group VIII metal elements; and based on the total weight of the hydrocracking catalyst, the content of the Group VIB metal element calculated as oxide is 15wt%-33wt%, and / or the content of the Group VIII metal element calculated as oxide is 2wt%-8wt%.

14. The method according to claim 13, wherein Based on the total weight of the carrier III, the content of the acidic component is 40 wt%-75 wt%.

15. The method according to claim 13, wherein Based on the total weight of the acidic components, the content of the Y-type molecular sieve is 60wt%-100wt%.

16. The method according to claim 5, wherein In step (1), the hydrogenation protected catalyst contains a carrier IV and an active metal component IV supported on the carrier IV, the carrier IV is selected from at least one of aluminum oxide, silicon oxide and titanium oxide, and the active metal component IV contains at least one metal element selected from Group VIII non-noble metal elements and Group VIB metal elements; and the content of the active metal component IV in terms of oxide is 0.1 wt% to 15 wt% based on the total weight of the hydrogenation protected catalyst.

17. The method according to claim 16, wherein: The linear average particle size of the hydrogenation protection catalyst is 0.5 mm to 50.0 mm, and the bulk density is 0.3 g / cm 3 -1.2g / cm 3 , with a specific surface area of 50m 2 / g-300m 2 / g.

18. The method according to claim 5, wherein: In step (1), the hydrodemetallization catalyst contains a carrier V and an active metal component V supported on the carrier V, the carrier V is selected from at least one of aluminum oxide, silicon oxide and titanium oxide, and the active metal component V contains at least one metal element selected from Group VIII non-noble metal elements and Group VIB metal elements; and the content of the active metal component V calculated as oxide is 3 wt% to 30 wt% based on the total weight of the hydrodemetallization catalyst.

19. The method according to claim 18, wherein The linear average particle size of the hydrodemetallization catalyst is 0.2 mm to 6.0 mm, and the bulk density is 0.3 g / cm 3 -0.8g / cm 3 , with a specific surface area of 100m 2 / g-250m 2 / g.

20. The method according to any one of claims 1 to 4, wherein: In step (1) and step (2), the conditions of the first reaction and the second reaction independently include: hydrogen partial pressure of 10.0 MPa-20.0 MPa, reaction temperature of 280°C-400°C, liquid hourly space velocity of 0.5 h -1 -6h -1 , the hydrogen-to-oil volume ratio is 300-2000.

21. The method according to any one of claims 1 to 4, wherein: In step (3), the conditions of the third reaction include: hydrogen partial pressure of 6.0MPa-20.0MPa, reaction temperature of 290℃-420℃, liquid hourly space velocity of 0.3h -1 -5h -1 , the hydrogen-to-oil volume ratio is 300-2000.

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