Two-stage hydrocracking method

Abstract

The invention relates to the technical field of heavy inferior wax oil processing, and discloses a two-stage hydrocracking method. The method comprises the following steps: introducing heavy inferior wax oil into a hydrofining reaction zone I filled with a hydrofining catalyst I, and carrying out a first reaction to obtain a reaction effluent I; the reaction effluent I is introduced into a hydrofining reaction zone II filled with a hydrofining catalyst II for a second reaction, and a reaction effluent II is obtained; the reaction effluent II is introduced into a hydrocracking reaction zone filled with a hydrocracking catalyst for a third reaction, and a reaction effluent III is obtained; and separating the reaction effluent III to obtain a light naphtha fraction, a heavy naphtha fraction, middle distillate oil and a tail oil fraction. By adopting the method provided by the invention, the heavy inferior wax oil raw material can be converted into the high-quality chemical raw material and the clean fuel.

Description

Technical Field

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

[0002] In recent years, the demand for automotive diesel in domestic refined oil products has shrunk, the growth rate of gasoline consumption demand has slowed down, and the market demand for chemical raw materials represented by olefins and aromatics has increased year by year. Therefore, the transformation of refining to chemical industry is an important development direction at present. Heavy naphtha, a hydrocracking product, can be used as a raw material for the reforming unit to produce aromatics, and the product tail oil can be used as a raw material for the catalytic cracking unit to produce products such as ethylene and propylene. In addition, as the amount of crude oil production increases year by year, the supply of high-quality crude oil and conventional crude oil decreases year by year and the price rises, while the supply of heavy and inferior crude oil increases year by year and the price is relatively low. However, the processing of heavy and inferior crude oil is difficult and costly, and the process conditions of the existing hydrocracking unit cannot meet its deep processing needs.

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

[0004] In order to meet the processing needs of heavy and inferior crude oil, in recent years, delayed coking technology for lightening heavy oil, slurry bed, ebullating bed, and suspended bed heavy oil hydrocracking technology have been further developed. However, heavy oil delayed coking, slurry bed, ebullating bed, and suspended bed heavy oil hydrocracking technology will produce a considerable proportion of wax oil fractions or heavy distillate oils in 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 residual carbon value, among which the density at 20℃ 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 very 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. The method realizes the production of conventional hydrocracking products by processing heavy straight-run wax oil raw materials with low nitrogen content but complex nitrogen-containing compound structure through two-stage denitrogenation means.

[0006] CN104611053A discloses a high-drying point raw material hydrocracking process, which adopts a two-stage denitrification method, and by setting a gas-liquid countercurrent contact reaction zone and a gas-liquid separation zone in one stage, it is possible to process heavy and inferior deep-pulled 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 inferior 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 with two fractionation units to achieve conversion of inferior raw oil with a nitrogen content greater than 2000 μg / g and a final distillation point of about 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 raw material. The method realizes the conversion of the high-nitrogen raw material 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. The method realizes the conversion of heavy and inferior raw materials with a final distillation point of 580°C-620°C into conventional clean oil products and chemical raw materials by arranging a gas-liquid separation in the second refining reaction zone equipped with a bulk catalyst.

[0012] CN104611022A discloses a two-stage hydrocracking method for inferior heavy distillate oil. The method realizes the conversion of heavy inferior raw materials with a nitrogen content of 2000 μg / g-15000 μg / 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 realizes 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 highly nitrogen-resistant hydrocracking catalysts in the cracking reaction zone.

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

[0015] On the one hand, the raw materials processed by the existing hydrocracking technology are not of low quality and it is difficult to match the processing needs of low-quality raw materials; on the other hand, the 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 the hydrocracking technology for directly processing heavy and low-quality wax oil to produce reforming and high-quality tail oil that can be used as raw materials 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 of refining enterprises in processing heavy and inferior crude oil and the enhancement of product value. Summary of the invention

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

[0018] In order to achieve the above object, the present invention provides a two-stage hydrocracking method, which 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, and the method comprises:

[0019] (1) introducing the heavy low-quality wax oil into the hydrotreating reaction zone I filled with the hydrotreating catalyst I to carry out 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 carry out 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 carry out 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, an intermediate distillate oil and a tail oil fraction;

[0023] The 95% distillation temperature of the heavy low-quality wax oil according to ASTM D-1160 is 580° C.-700° C., the nitrogen content is 1800 μg / g-3500 μg / g, and the sum of the content of cycloalkanes with two or more rings and aromatics with two or more rings is 50 wt %-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 inferior wax oil into a hydrorefining reaction zone I and a hydrorefining reaction zone II in sequence to carry out a two-stage hydrorefining reaction, and simultaneously controls the weight ratio of the metal active components contained in the hydrorefining catalyst I and the hydrorefining catalyst II, and coordinates the process conditions of the hydrorefining reaction to convert the heavy and inferior wax oil raw material into a high-quality chemical raw material and clean fuel. DETAILED DESCRIPTION

[0028] The endpoints and any values ​​of the ranges disclosed in this article 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 endpoint values ​​of each range, the endpoint values ​​of each range and the 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 as specifically disclosed in this article.

[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 more aromatic hydrocarbons in the heavy low-quality wax oil=the mass of two-ring or more 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 chain alkanes, cycloalkanes and aromatic hydrocarbons, and the chain 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) of SH / T 0572-1993, and the pore volume is tested with reference to the zeolite specific surface area and micropore volume determination method in catalyst of NB / SH / T 0571-2021.

[0037] In the present invention, the mesopore area and specific surface area are tested with reference to the method for measuring specific surface area and micropore volume of zeolite in catalysts in NB / SH / T 0571-2021 and the method for measuring surface area of ​​catalysts and adsorbents in GB / T 5816-1995.

[0038] As mentioned above, the present invention provides a two-stage hydrocracking method, which 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, and the method comprises:

[0039] (1) introducing the heavy low-quality wax oil into the hydrotreating reaction zone I filled with the hydrotreating catalyst I to carry out 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 carry out 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 carry out 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, an intermediate distillate oil and a tail oil fraction;

[0043] The 95% distillation temperature of the heavy low-quality wax oil according to ASTM D-1160 is 580° C.-700° C., the nitrogen content is 1800 μg / g-3500 μg / g, and the sum of the content of cycloalkanes with two or more rings and aromatics with two or more rings is 50 wt %-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] The inventors of the present invention have discovered during the course of their research that by loading different hydrorefining catalysts having active metal component content ratios within a certain range in 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 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 the aromatic saturation in the hydrorefining catalytic reaction zone II to reduce the reaction hydrogen consumption is achieved.

[0048] At the same time, the inventors of the present invention also found during the research process that, after carrying out 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, so that the aromatic saturation in the hydrorefining catalytic reaction zone II and the ring-opening cracking in the cracking reaction zone can be carried out more efficiently; in addition, by retaining a certain content of sulfur-containing compounds, a certain concentration of hydrogen sulfide can be provided for the sulfide active center of the catalyst in the hydrorefining catalytic reaction zone II and the hydrocracking reaction zone, thereby ensuring the stability of the active center of the catalyst.

[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 hydrofining 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 raw materials.

[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 condition, 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 found 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 achieve a reduction in the amount of catalyst while effectively increasing the aromatic saturation rate, thereby reducing the investment cost of the reactor and the use cost of the catalyst.

[0052] Preferably, in step (4), the initial distillation 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 condition, 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 hydrotreating reaction zone I, according to the flow direction of the liquid phase material, a hydroprotection catalyst and a hydrodemetallization catalyst are sequentially loaded upstream of the hydrotreating catalyst I.

[0055] Further preferably, in step (1), based on the total volume of the catalyst in the hydrotreating reaction zone I, the loading volume content of the hydroprotection 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 based on the total weight of the hydrorefining catalyst I, the content of the active metal component I in terms of oxide is 35 wt%-55 wt%.

[0057] More preferably, in step (1), in the hydrotreating catalyst I, the Group VIII non-precious metal element is selected from at least one of nickel and cobalt, and the Group VIB non-precious 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-precious metal elements of Group VIII calculated as oxides is 1wt%-15wt%, and the content of the non-precious metal elements of Group VIB calculated as oxides is 5wt%-40wt%.

[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 size 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 hydrotreating 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 based on the total weight of the hydrotreating catalyst II, the content of the active metal component II in terms of oxide is 35wt%-55wt%.

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

[0063] More preferably, based on the total weight of the hydrotreating catalyst II, the content of the non-noble metal elements of Group VIII is 1 wt%-15 wt%, and the content of the non-noble metal elements of Group VIB in terms of oxide 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, based on the total weight of the acidic components, the content of the Y-type molecular sieve is 60wt%-100wt%. The inventors of the present invention have found that under this preferred condition, the heavy low-quality wax oil feedstock can be cracked and converted into heavy naphtha effectively and highly selectively.

[0067] Preferably, in step (1), the hydrogenation protection 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 non-precious metal elements of Group VIII and metal elements of Group VIB; and the content of the active metal component IV in terms of oxide is 0.1 wt%-15 wt% based on the total weight of the hydrogenation protection catalyst.

[0068] Furthermore, the linear average particle size of the hydrogenation protection catalyst is 0.5 mm-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 non-precious metal elements of Group VIII and metal elements of Group VIB; and the content of the active metal component V in terms of oxide is 3 wt%-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-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 volume ratio of hydrogen to oil is 300-2000.

[0072] According to another preferred embodiment, in step (3), the conditions of the third reaction include: hydrogen partial pressure of 6.0 MPa-20.0 MPa, reaction temperature of 290°C-420°C, liquid hourly space velocity of 0.3 h -1 -5h -1 , the volume ratio of hydrogen to oil 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 by way of 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 an outer 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 an alumina carrier I1;

[0079] 200 g of carrier I1 was placed in a polytetrafluoroethylene-lined self-pressure sealed autoclave, 100 g of deionized water was added to seal, and the autoclave was subjected to constant temperature hydrothermal treatment at 90° C. for 12 h, and then filtered. 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 then filtered for 1h. 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 soaked for 1h, then filtered, and the obtained solid was dried at 120°C for 3h to obtain refined CAT1.

[0081] In the following example,

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

[0083] The yield of the heavy naphtha fraction is defined as: the mass of the separated heavy naphtha fraction (initial distillation point is 65°C, final distillation point is 165°C-175°C) / the mass of the 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 inferior wax oil × 100%; T1 is the initial distillation 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 inferior wax oil × 100%.

[0086] raw material:

[0087] Hydrotreating catalysts:

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

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

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

[0091] Hydrogenation protection catalyst:

[0092] Protective CAT3: Brand 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 RG-201, carrier IV is alumina, calculated as oxide, the content of molybdenum is 1.2wt%, the content of nickel 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 RG-30A, carrier IV is alumina, calculated as oxide, the content of molybdenum is 2.5wt%, the content of nickel 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] Protection CAT6: Brand RG-30B, carrier IV is alumina, calculated as oxide, molybdenum content is 5.5wt%, nickel content is 1.0wt%, linear average particle size is 3.0mm, 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 molybdenum content is 7.5wt%, the nickel content 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 27.0wt% and a nickel content of 2.7wt% based on oxides, and the balance being carrier III; based on the total weight of carrier III, the acidic component content is 65wt%, and the balance is alumina; based on the total weight of the acidic components, the Y-type molecular sieve content is 100wt%;

[0100] Cracking CAT9: The brand is RHC-133. Calculated as oxide, 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 content of acidic components is 20wt%, and the balance is alumina; calculated based on the total weight of acidic components, the content of Y-type molecular sieve is 50wt%, and the balance is amorphous silicon aluminum.

[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 the hydrotreating catalyst I to carry out 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 carry out 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 carry out 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, an intermediate 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 condition 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 in this embodiment:

[0114] The reaction temperature of the second reaction was 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 in this embodiment:

[0122] The reaction temperature of the second reaction was 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 in this embodiment:

[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 example, 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 in this embodiment:

[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 example, 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 in this embodiment:

[0143] The loading amount of each catalyst in the hydrofining reaction zone I is 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 carry out 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 carry out 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 carry out 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, an intermediate distillate oil and a tail oil fraction;

[0155] The specific process condition 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 in this comparative example:

[0158] The reaction temperature of 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 is replaced by refined CAT1;

[0161] The loading volume ratio of the hydrofining catalyst I to the 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 in this comparative example:

[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 is replaced by 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 was 365°C;

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

[0188] The loading volume ratio of the hydrofining catalyst I to the 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 is 24.2%, and the desulfurization rate is 91.5%; the nitrogen mass fraction in the reaction effluent II is 10 μg·g -1 , the total aromatic saturation rate is 67.51%; the sum of the yields of the light naphtha fraction and the 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 is carried out in the same manner as comparative example 5, except that in this example: the reaction temperature of the third reaction is 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 comparative example 5, except that in this embodiment:

[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+Demetallized CAT7+Refined CAT1 means that according to the flow direction of liquid materials, protection CAT3, protection CAT4, protection CAT5, protection CAT6, demetallized CAT7 and refined CAT1 are loaded in sequence;

[0208] 2. The column of packing volume ratio refers to the packing 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 inferior wax oil is controlled within the range of 85%-92%, and 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 hydrotreating catalyst I and the hydrotreating catalyst II in terms of 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; 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 could be 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 with an acidic component, especially a Y-type molecular sieve content of less than 60 wt%, was used. Although qualified products could be obtained, a very high operating temperature was required due to the significant reduction in catalyst activity, resulting in a mismatch between the operating temperatures of the hydrofining reaction zone II and the hydrocracking reaction zone, requiring additional heating measures, which increased the operating cost.

[0215] In Example 9, the loading volume ratio of the hydroprotection catalyst and the hydrodemetallization catalyst in the hydrofining reaction zone I is increased, so that the loading volume ratio of the hydrofining catalyst I is less than 60%. Although the product distribution and quality similar to those of Example 1 can be obtained under similar reaction conditions, due to the low number of active centers of the hydroprotection catalyst and the hydrodemetallization catalyst, a large loading ratio will lead to a significant increase in the reactor volume, thereby increasing the reactor manufacturing cost and the device 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 relatively low, 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°C, the sum of the yields of light naphtha fraction and heavy naphtha is 47.33%; it can be seen that when the method provided by the present invention is not adopted, it is difficult to realize the conversion of heavy and inferior wax oil raw materials into chemical raw materials in large proportion;

[0217] In comparative example 2, the loading volume ratio of the hydrofining catalyst I to the hydrofining catalyst II is adjusted to 0.2:1. At the harsh reaction temperature of 385°C, the desulfurization rate of the heavy inferior wax oil is only 63.2%, and the total aromatic saturation rate of the reaction effluent I is only 7.5%, which increases the severity of the reaction in the hydrofining reaction zone II. At a reaction temperature of 385°C, the total aromatic saturation rate of the reaction effluent II is only 53.56%, which increases the difficulty of the hydrocracking reaction. The corresponding naphtha fraction yield at a cracking reaction temperature of 387°C is only 51.51%, which not only increases the fuel gas consumption in the reaction process, increases the energy consumption of the device, but also shortens the operation cycle of the catalyst, making the economic efficiency of the reaction process worse.

[0218] In Comparative Examples 3 and 5 to 7, hydrofining catalyst CAT2-2 and hydrofining catalyst CAT are used to replace hydrofining catalyst CAT2-1, so that the weight ratio of the content of active metal component I to the content of active metal component II is not 1.55-1.70:1, and a higher reaction temperature is used in the hydrofining reaction zone II. Although similar effects to those of the embodiments provided by the present invention can be obtained, the diesel yield of the product is high and the heavy naphtha aromatic potential is low, indicating that the hydrogen consumption in the reaction process increases, and the expectation of reducing hydrogen consumption is not achieved;

[0219] In Comparative Example 4, the reaction temperature in the hydrotreating reaction zone I was increased to 395° C. to increase the total aromatic saturation rate of the reaction effluent I to 27.3%, while keeping the reaction conditions of the hydrotreating reaction zone II and the hydrocracking reaction zone similar. 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 hydrotreating reaction zone I is too high, which is not conducive to the long-term operation of the hydrotreating reaction zone I.

[0220] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope 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 hydrotreating reaction zone I filled with the hydrotreating 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; (3) introducing the reaction effluent II into the hydrocracking reaction zone filled with a hydrocracking catalyst to carry out 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; The 95% distillation temperature of the heavy low-quality wax oil according to ASTM D-1160 is 580° C.-700° C., the nitrogen content is 1800 μg / g-3500 μg / g, and the sum of the content of cycloalkanes with two or more rings and aromatics with two or more rings is 50 wt %-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; 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%.

2. The method according to claim 1, wherein: 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%.

3. The method according to claim 1 or 2, wherein: 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%.

4. The method according to any one of claims 1 to 3, wherein: 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.

5. The method according to any one of claims 1 to 4, wherein: In step (4), the initial distillation point of the tail oil fraction is 340°C-360°C.

6. The method according to any one of claims 1 to 5, 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%; Preferably, in step (1), in the hydrofining reaction zone I, according to the flow direction of the liquid phase material, a hydroprotection catalyst and a hydrodemetallization catalyst are sequentially loaded upstream of the hydrofining catalyst I; Preferably, in step (1), based on the total volume of the catalyst in the hydrotreating 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%.

7. The method according to any one of claims 1 to 6, 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 the non-precious metal elements of Group VIII and the non-precious metal elements of Group VIB; and the content of the active metal component I in terms of oxide is 35 wt% to 55 wt% based on the total weight of the hydrorefining catalyst I; Preferably, in step (1), in the hydrotreating catalyst I, the non-precious metal element of Group VIII is selected from at least one of nickel and cobalt, and the non-precious metal element of Group VIB is a combination of molybdenum and tungsten; Preferably, in step (1), based on the total weight of the hydrotreating catalyst I, the content of the non-precious metal elements of Group VIII calculated as oxides is 1wt%-15wt%, and the content of the non-precious metal elements of Group VIB calculated as oxides is 5wt%-40wt%.

8. The method according to claim 7, wherein: In step (1), in the hydrotreating 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; Preferably, in step (1), in the hydrotreating catalyst I, in the carrier I, the ratio of the mesopore area to the total specific surface area is 0.3-0.7:

1.

9. The method according to any one of claims 1 to 8, wherein: In step (2), in the hydrorefining catalyst II, the carrier II is alumina or silicon oxide-alumina, and the active metal component II contains at least one metal element selected from the non-precious metal elements of Group VIII and the non-precious metal elements of Group VIB; 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; Preferably, in step (2), in the hydrotreating catalyst II, the non-noble metal element of Group VIII is selected from at least one of nickel and cobalt, and the non-noble metal element of Group VIB is selected from at least one of molybdenum and tungsten; Preferably, based on the total weight of the hydrotreating catalyst II, the content of the non-noble metal element of Group VIII is 1 wt%-15 wt%, and the content of the non-noble metal element of Group VIB in terms of oxide is 5 wt%-40 wt%.

10. The method according to any one of claims 1 to 9, 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%; Preferably, based on the total weight of the carrier III, the content of the acidic component is 40wt%-75wt%; Preferably, based on the total weight of the acidic components, the content of the Y-type molecular sieve is 60wt%-100wt%.

11. The method according to any one of claims 6 to 10, wherein: In step (1), the hydrogenation protection 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 non-precious metal elements of Group VIII and metal elements of Group VIB; 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 protection catalyst; Preferably, the linear average particle size of the hydrogenation protection catalyst is 0.5 mm-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.

12. The method according to any one of claims 6 to 11, 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 non-precious metal elements of Group VIII and metal elements of Group VIB; 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; 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.

13. The method according to any one of claims 1 to 12, wherein: 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 volume ratio of hydrogen to oil is 300-2000.

14. The method according to any one of claims 1 to 13, wherein: In step (3), the conditions of the third reaction include: hydrogen partial pressure of 6.0MPa-20.0MPa, reaction temperature of 290°C-420°C, liquid hourly space velocity of 0.3h -1 -5h -1 , the volume ratio of hydrogen to oil is 300-2000.

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