A hydrocracking method for producing more chemical raw materials

Abstract

The present invention relates to the technical field of heavy and low-quality wax oil processing, and discloses a hydrocracking method for producing high-yield chemical raw materials. The method comprises: introducing heavy and low-quality wax oil into a hydrorefining reaction zone for a first reaction to obtain a reaction effluent I; introducing the reaction effluent I into a hydrocracking reaction zone I for a second reaction to obtain a reaction effluent II, thereby obtaining a light naphtha fraction I, a heavy naphtha fraction I, an intermediate distillate oil I, and a tail oil fraction I; introducing the intermediate material into a hydrocracking reaction zone II for a third reaction to obtain a reaction effluent III, thereby obtaining a light naphtha fraction II, a heavy naphtha fraction II, an intermediate distillate oil II, and a tail oil fraction II; and recycling the recycled material to the hydrocracking reaction zone II for a third reaction. The method provided by the present invention can convert the heavy and low-quality wax oil feedstock into chemical raw materials at the maximum ratio.

Description

Technical Field

[0001] The present invention relates to the technical field of heavy and inferior wax oil processing, in particular to a hydrocracking method for producing high-yield chemical raw materials. Background Art

[0002] In recent years, with the continued development of the international energy and chemical industries, crude oil production has increased annually. However, as a non-renewable resource, the supply of high-quality and conventional crude oil has decreased and its price has risen with increasing production. Meanwhile, the supply of heavy and low-quality crude oil has increased annually, and its price has remained relatively low. Although heavy and low-quality crude oil is difficult and costly to process, refineries can achieve significant economic returns by selecting appropriate refining technologies and product solutions, processing this inexpensive and abundant source of crude oil.

[0003] 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.

[0004] 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.

[0005] 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.

[0006] 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.

[0007] 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.

[0008] 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.

[0009] 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.

[0010] 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.

[0011] 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.

[0012] 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.

[0013] However, there are two main problems in the above existing hydrocracking technology:

[0014] On the one hand, the raw materials processed by existing hydrocracking technology are not of low quality and cannot meet 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, and there is little research on the conversion of heavy and low-quality wax oil and product route development.

[0015] To this end, the development of hydrocracking technology to lighten and enhance the value of heavy and inferior wax oil raw materials is of great significance for refining and chemical companies to achieve high-value conversion of heavy and inferior crude oil. Summary of the Invention

[0016] The purpose of the present invention is to solve the problems of difficult conversion of heavy and inferior wax oil raw materials and relatively single product routes in the prior art, and to provide a flexible and high-yield heavy and inferior wax oil hydrocracking method for chemical raw materials.

[0017] To achieve the above-mentioned object, the present invention provides a hydrocracking method for producing a large amount of chemical raw materials. The method is carried out in an apparatus comprising a hydrorefining reaction zone and a hydrocracking reaction zone, wherein the hydrocracking reaction zone comprises a hydrocracking reaction zone I and a hydrocracking reaction zone II. The method comprises:

[0018] (1) introducing the heavy low-quality wax oil into the hydrotreating reaction zone filled with a hydrotreating catalyst to carry out a first reaction to obtain a reaction effluent I;

[0019] (2) introducing the reaction effluent I into the hydrocracking reaction zone I filled with a hydrocracking catalyst I to carry out a second reaction to obtain a reaction effluent II; separating the reaction effluent II to obtain a light naphtha fraction I, a heavy naphtha fraction I, a middle distillate oil I, and a tail oil fraction I;

[0020] (3) introducing the intermediate material into the hydrocracking reaction zone II filled with a hydrocracking catalyst II to carry out a third reaction to obtain a reaction effluent III; and separating the reaction effluent III to obtain a light naphtha fraction II, a heavy naphtha fraction II, a middle distillate oil II, and a tail oil fraction II;

[0021] (4) circulating the recycled material to the hydrocracking reaction zone II to carry out the third reaction;

[0022] 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 %.

[0023] The hydrorefining catalyst contains a carrier I and an active metal component I supported on the carrier I, and the hydrocracking catalyst I 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 1.35-1.60:1;

[0024] The intermediate material is selected from at least one of the middle distillate oil I and the tail oil fraction I; the recycled material is selected from at least one of the middle distillate oil II and the tail oil fraction II.

[0025] The present invention introduces heavy low-quality wax oil into a hydrorefining reaction zone for a hydrorefining reaction, then introduces the obtained reaction effluent into a hydrocracking reaction zone I for a hydrocracking reaction, partially introduces the obtained reaction effluent into a hydrocracking reaction zone II for a further hydrocracking reaction, and recycles a portion of the reaction effluent to the hydrocracking reaction zone II. Meanwhile, the weight ratio of the metal active components contained in the hydrorefining catalyst I and the hydrocracking catalyst I is controlled, thereby converting the heavy low-quality wax oil raw material into a chemical raw material at a maximum ratio. DETAILED DESCRIPTION

[0026] 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.

[0027] 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%.

[0028] 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%.

[0029] In the present invention, the hydrocarbon family includes alkanes, cycloalkanes and aromatic hydrocarbons, and the alkanes include straight-chain alkanes and branched-chain alkanes.

[0030] 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%.

[0031] 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.

[0032] In the present invention, the pore size test is carried out with reference to the SH / T0572-1993 catalyst pore size distribution calculation method (nitrogen desorption isotherm calculation method), and the pore volume is tested with reference to the NB / SH / T0571-2021 zeolite specific surface area and micropore volume determination method in catalysts.

[0033] In the present invention, the mesopore area and specific surface area are tested with reference to the NB / SH / T0571-2021 method for determining the specific surface area and micropore volume of zeolite in catalysts and the GB / T5816-1995 method for determining the surface area of catalysts and adsorbents.

[0034] As described above, the present invention provides a hydrocracking method for increasing the yield of chemical raw materials. The method is carried out in an apparatus comprising a hydrorefining reaction zone and a hydrocracking reaction zone, wherein the hydrocracking reaction zone comprises a hydrocracking reaction zone I and a hydrocracking reaction zone II. The method comprises:

[0035] (1) introducing the heavy low-quality wax oil into the hydrotreating reaction zone filled with a hydrotreating catalyst to carry out a first reaction to obtain a reaction effluent I;

[0036] (2) introducing the reaction effluent I into the hydrocracking reaction zone I filled with a hydrocracking catalyst I to carry out a second reaction to obtain a reaction effluent II; separating the reaction effluent II to obtain a light naphtha fraction I, a heavy naphtha fraction I, a middle distillate oil I, and a tail oil fraction I;

[0037] (3) introducing the intermediate material into the hydrocracking reaction zone II filled with a hydrocracking catalyst II to carry out a third reaction to obtain a reaction effluent III; and separating the reaction effluent III to obtain a light naphtha fraction II, a heavy naphtha fraction II, a middle distillate oil II, and a tail oil fraction II;

[0038] (4) circulating the recycled material to the hydrocracking reaction zone II to carry out the third reaction;

[0039] 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 %.

[0040] The hydrorefining catalyst contains a carrier I and an active metal component I supported on the carrier I, and the hydrocracking catalyst I 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 1.35-1.60:1;

[0041] The intermediate material is selected from at least one of the middle distillate oil I and the tail oil fraction I; the recycled material is selected from at least one of the middle distillate oil II and the tail oil fraction II.

[0042] During the research process, the inventors of the present invention discovered that due to the high content of sulfur and nitrogen impurities in heavy and inferior wax oil raw materials, the high carbon number and condensation degree of aromatic hydrocarbons, during the hydrogenation refining reaction, on the one hand, the removal of sulfur and nitrogen compounds will generate hydrogen sulfide and ammonia, which will increase the partial pressure of hydrogen sulfide and ammonia in the reaction system, thereby inhibiting the saturation reaction of aromatic hydrocarbons, which is not conducive to the saturation reaction of aromatic hydrocarbons in heavy and inferior wax oil raw materials; on the other hand, the carbon number and condensation degree of aromatic hydrocarbons in heavy and inferior wax oil raw materials are high, and deep hydrogenation saturation is more difficult. Typically, in the hydrorefining reaction of heavy, low-quality wax oil raw materials, when the nitrogen content in the feed is removed to ≯20μg / g, a relatively high proportion of aromatics in the refined oil still remain unsaturated. In order to ensure that the aromatic compounds in the hydrocracking reaction can meet the reaction requirements of ring-opening cracking, the hydrocracking catalyst is usually required to have at least a considerable proportion of active metal component content to ensure that the number of metal active centers can meet the saturation of aromatic rings into cycloalkanes capable of ring-opening cracking. In addition, when heavy, low-quality wax oil raw materials are used to produce heavy naphtha as a reforming material, an excessively high active metal component content in the hydrocracking catalyst will not only cause the aromatic compounds in the heavy naphtha to continue to be saturated into cycloalkanes and open the ring, thereby leading to excessive consumption of hydrogen and increased catalyst costs, but also unreasonable process economics. Therefore, according to the processing requirements of heavy and inferior wax oil raw materials, the contents of active metal components in the hydrorefining catalyst and the hydrocracking catalyst I need to be reasonably matched. Specifically, 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 1.35-1.60:1.

[0043] Preferably, in step (1), the conditions of the first reaction are controlled so that the total aromatic saturation rate in the reaction effluent I is 43%-60%. The inventors of the present invention have found that under this preferred condition, hydrogenation saturation of aromatics, especially polycyclic aromatic hydrocarbons, can be achieved. This can, on the one hand, slow down the deactivation of the cracking catalyst and extend the operating cycle of the device, and on the other hand, improve the conversion capacity of the cracking agent and reduce the reaction severity of the cracking catalyst.

[0044] Preferably, the conditions of the second reaction are controlled so that the ratio of the sum of the masses of the middle distillate oil I and the tail oil fraction I to the mass of the heavy and inferior wax oil is 0.6-0.8:1. The inventors of the present invention have discovered that when the mass ratio of the sum of the mass fractions of the middle distillate oil I and the tail oil distillate oil I to the mass of the heavy and inferior wax oil is controlled at below 0.6:1, the conversion ratio of the hydrocracking reaction zone I is insufficient, resulting in a high proportion of feedstock entering the hydrocracking reaction zone II and poor feed properties, thereby increasing the reaction severity of the hydrocracking reaction zone II. It is usually necessary to reduce the space velocity of the hydrocracking reaction zone II, that is, to increase the volume of the reactor of the hydrocracking reaction zone II, thereby increasing the investment in the reactor. When the mass ratio of the sum of the mass fractions of the middle distillate oil I and the tail oil distillate oil I to the heavy and inferior wax oil is controlled at above 0.8:1, on the one hand, the severity of the cracking reaction is sharply increased, shortening the operating cycle of the device. On the other hand, at excessively high reaction temperatures, the proportion of secondary cracking reactions is increased, resulting in an increase in the yield of the product dry gas and liquefied gas, making the selectivity of the reaction process unreasonable. When the mass ratio of the sum of the mass fractions of the middle distillate oil I and the tail oil distillate oil I to the mass of the heavy low-quality wax oil is controlled within the range of 0.6-0.8:1, the operating cycle of the device is effectively extended by matching the catalyst activities in the hydrocracking reaction zone I and the hydrocracking reaction zone II. At the same time, by optimizing the reaction conditions, the reactor volume of the hydrocracking reaction zone II is reduced while reducing the secondary cracking reaction in the hydrocracking reaction zone I, thereby reducing the reactor investment cost and operating cost, and making the process economical more reasonable.

[0045] Preferably, the conditions of the third reaction are controlled so that the ratio of the sum of the masses of the middle distillate oil II and the tail oil fraction II to the mass of the intermediate material is 0.4-0.6:1. The inventors of the present invention have found that when the ratio of the sum of the masses of the middle distillate oil II and the tail oil fraction II to the mass of the intermediate material is controlled below 0.4:1, the intermediate material is in a low-sulfur, low-nitrogen reaction environment, the reaction conversion depth is high, and on the one hand, a large amount of cold hydrogen is required to control the reaction temperature, which increases the investment cost of the circulating hydrogen compressor. At the same time, due to the excessive heat release of the reaction, the proportion of secondary cracking increases, and accordingly the yield of the dry gas and liquefied gas products increases, and the selectivity of the target product decreases. When the ratio of the sum of the masses of the middle distillate oil II and the tail oil fraction II to the mass of the intermediate material is controlled above 0.6:1, although cold hydrogen can be saved and the selectivity of the target product can be improved, the investment cost of the circulating oil pump will be correspondingly increased, and the energy consumption of the device operation will be significantly increased. When the ratio of the sum of the masses of the intermediate distillate oil II and the tail oil distillate II to the mass of the intermediate material is controlled within the range of 0.4-0.6:1, the amount of circulating oil can be reduced while saving cold hydrogen, thereby reducing the investment cost of the circulating hydrogen compressor and the circulating oil pump, and at the same time improving the selectivity of the target product of the reaction process.

[0046] Preferably, in step (2), in the hydrocracking catalyst I, the carrier II contains a heat-resistant inorganic oxide I and an acidic component I, the heat-resistant inorganic oxide I is selected from at least one of silicon oxide and aluminum oxide, and the acidic component I contains a Y-type molecular sieve; the active metal component II 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 I, 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%.

[0047] More preferably, based on the total weight of the carrier II, the content of the acidic component I is 45 wt%-75 wt%.

[0048] Preferably, in step (3), the hydrocracking catalyst II contains a carrier III and an active metal component III supported on the carrier III; the carrier III contains a heat-resistant inorganic oxide II and an acidic component II, the heat-resistant inorganic oxide II is selected from at least one of silicon oxide and aluminum oxide, and the acidic component II 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 II, 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%.

[0049] Preferably, in steps (2) and (3), the content of the Y-type molecular sieve in the hydrocracking catalyst I is 0-25 wt% higher than the content of the Y-type molecular sieve in the hydrocracking catalyst II. The inventors of the present invention have found that this preferred embodiment not only improves the cracking ability of heavy and low-quality wax oil feedstocks and reduces the reaction severity, but also improves the selectivity of converting heavy and low-quality wax oils into heavy naphtha fractions.

[0050] Preferably, in step (1), in the hydrorefining catalyst, 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%-55 wt% based on the total weight of the hydrorefining catalyst.

[0051] Further preferably, in step (1), in the hydrorefining catalyst, 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;

[0052] More preferably, in step (1), based on the total weight of the hydrotreating catalyst, 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%.

[0053] Preferably, in step (1), in the hydrorefining catalyst, 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.

[0054] Furthermore, in step (1), in the hydrorefining catalyst, 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 external surface area.

[0055] According to a preferred embodiment, in step (1), in the hydrorefining reaction zone, 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.

[0056] Further preferably, in step (1), in the hydrorefining reaction zone, the hydroprotected catalyst comprises a combination of at least four hydroprotected catalysts, wherein the active metal component content increases sequentially in the direction of liquid phase flow. The inventors of the present invention have discovered that this preferred embodiment allows for the effective removal of metal impurities from heavy, low-quality wax oil while rationally matching the reaction temperature steps and distributing the refining reaction heat, thereby extending the operating cycle of the demetallization catalyst.

[0057] Particularly preferably, in step (1), based on the total volume of the catalyst in the hydrorefining reaction zone, the loading volume content of the hydrogenation protection catalyst is 5%-25%, the loading volume content of the hydrodemetallization catalyst is 5%-15%, and the loading volume content of the hydrorefining catalyst is 60%-90%.

[0058] According to another preferred embodiment, in step (3), a hydrogenation protection catalyst is loaded upstream of the hydrocracking catalyst II in the hydrocracking reaction zone II, and the loading volume of the hydrocracking catalyst II is 75% to 92% based on the total volume of the catalyst in the hydrocracking reaction zone II. The inventors of the present invention have discovered that this preferred embodiment can effectively remove impurities or polycyclic aromatic hydrocarbons from the circulating material or device system, thereby achieving the goal of slowing the deactivation rate of the hydrocracking catalyst II.

[0059] Preferably, in step (1) and step (3), 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-precious 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.

[0060] More preferably, 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.

[0061] 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.

[0062] 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.

[0063] According to a preferred embodiment, in step (1), the conditions of the first reaction include: hydrogen partial pressure of 14.0 MPa-20.0 MPa, reaction temperature of 280°C-420°C, liquid hourly space velocity of 0.5 h -1-6h -1 , the hydrogen-to-oil volume ratio is 300-2000.

[0064] According to another preferred embodiment, in step (2) and step (3), the conditions of the second reaction and the third reaction independently 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.

[0065] Preferably, the heavy low-quality wax oil is selected from at least one of straight-run wax oil and secondary processed oil.

[0066] 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.

[0067] In the present invention, the feed to the hydrocracking reaction zone II includes at least one of the middle distillate oil and the tail oil fraction from both the hydrocracking reaction zone I and the hydrocracking reaction zone II. Specifically, when only naphtha products are produced, the feed to the hydrocracking reaction zone II includes the middle distillate oil and the tail oil fraction from both the hydrocracking reaction zone I and the hydrocracking reaction zone II; when both naphtha and middle distillate oil are produced, the feed to the hydrocracking reaction zone II includes the tail oil fraction from both the hydrocracking reaction zone I and the hydrocracking reaction zone II.

[0068] The present invention will be described in detail below through examples.

[0069] In the following examples, unless otherwise specified, all raw materials used were commercially available.

[0070] In the following examples, the preparation method of purified CAT1 is as follows:

[0071] 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;

[0072] 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;

[0073] 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.

[0074] In the following example,

[0075] The yield of C1-C4 gas is defined as: the mass of separated C1-C4 gas / the mass of heavy low-quality wax oil × 100%;

[0076] Yield of light naphtha fraction (<65°C) = (mass of light naphtha fraction I + mass of light naphtha fraction II) / mass of heavy low-quality wax oil feedstock × 100%;

[0077] Yield of heavy naphtha fraction (initial boiling point 65°C, final boiling point 165°C-175°C) = (mass of heavy naphtha fraction I + mass of heavy naphtha fraction II) / mass of heavy low-quality wax oil feedstock × 100%;

[0078] The yield of the diesel fraction (175°C - T1°C) = (the mass of the middle distillate I + the mass of the middle distillate II) / the mass of the heavy low-quality wax oil feedstock × 100%; T1 is the initial distillation point of the tail oil fraction.

[0079] raw material:

[0080] Hydrorefining catalyst:

[0081] 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 71.68m 2 / g, and the ratio of the total specific surface area is 0.3106:1;

[0082] Hydrogenation protection catalyst:

[0083] Protective CAT2: Brand RG-200, carrier III 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 ;

[0084] Protective CAT3: Brand is RG-201, carrier III 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 ;

[0085] Protection CAT4: Brand is RG-30A, carrier III 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 3 ;

[0086] Protection CAT5: Brand is RG-30B, carrier III 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 ;

[0087] Hydrodemetallization catalyst:

[0088] Demetallized CAT6: The brand is RAM-100, the carrier IV 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 ;

[0089] Hydrocracking catalyst:

[0090] Cracking CAT7: RHC-210, with a tungsten content of 27.0 wt% and a nickel content of 2.7 wt% as oxides, with the balance being carrier II; based on the total weight of the carrier, the acidic component (all Y-type molecular sieves) contains 65 wt% of the acidic component, with the balance being alumina;

[0091] Cracking CAT8: The brand is RHC-210F. Calculated as oxides, the molybdenum content is 15.5wt%, the nickel content is 4.5wt%, and the balance is carrier III; calculated on the total weight of the carrier, the content of the acidic component (all Y-type molecular sieves) is 45wt%, and the balance is alumina.

[0092] In the following examples, the properties of the heavy low-quality wax oil used are shown in Table 1.

[0093] Table 1

[0094]

[0095] Example 1

[0096] (1) introducing the heavy low-quality wax oil into the hydrotreating reaction zone filled with a hydrotreating catalyst to carry out a first reaction to obtain a reaction effluent I;

[0097] (2) introducing the reaction effluent I into the hydrocracking reaction zone I filled with a hydrocracking catalyst I to carry out a second reaction to obtain a reaction effluent II; separating the reaction effluent II to obtain a light naphtha fraction I, a heavy naphtha fraction I, a middle distillate oil I, and a tail oil fraction I;

[0098] (3) introducing the intermediate material into the hydrocracking reaction zone II filled with a hydrocracking catalyst II to carry out a third reaction to obtain a reaction effluent III; and separating the reaction effluent III to obtain a light naphtha fraction II, a heavy naphtha fraction II, a middle distillate oil II, and a tail oil fraction II;

[0099] (4) circulating the recycled material to the hydrocracking reaction zone II to carry out the third reaction;

[0100] The specific process parameters are shown in Table 2, and the yield and property parameters of the product are shown in Table 3.

[0101] Example 2

[0102] This embodiment is carried out in the same manner as in embodiment 1, except that:

[0103] The reaction temperature of the second reaction is 380°C;

[0104] In this embodiment, the ratio of the sum of the mass of the middle distillate oil I and the tail oil fraction I to the mass of the heavy low-quality wax oil is 0.645:1; the ratio of the mass of the intermediate material to the mass of the heavy low-quality wax oil is 0.645:1;

[0105] The reaction temperature of the third reaction was 364°C;

[0106] In this embodiment, the ratio of the sum of the mass of the middle distillate II and the tail oil fraction II to the mass of the intermediate material is 0.5:1; and the ratio of the mass of the recycled material to the mass of the intermediate material is 0.5:1.

[0107] The remaining process parameters are the same as those in Example 1.

[0108] The yield and property parameters of the product are shown in Table 3.

[0109] Example 3

[0110] This embodiment is carried out in the same manner as in embodiment 1, except that:

[0111] The reaction temperature of the second reaction was 385°C and the hourly space velocity of the cracking liquid was 0.9h -1 ;

[0112] In this embodiment, the ratio of the sum of the mass of the middle distillate oil I and the tail oil fraction I to the mass of the heavy low-quality wax oil is 0.5267:1; the ratio of the mass of the intermediate material to the mass of the heavy low-quality wax oil is 0.5267:1;

[0113] The reaction temperature of the third reaction was 361°C;

[0114] In this embodiment, the ratio of the sum of the mass of the middle distillate II and the tail oil fraction II to the mass of the intermediate material is 0.4:1; and the ratio of the mass of the recycled material to the mass of the intermediate material is 0.4:1.

[0115] The remaining process parameters are the same as those in Example 1.

[0116] The yield and property parameters of the product are shown in Table 3.

[0117] Example 4

[0118] This embodiment is carried out in the same manner as in embodiment 1, except that:

[0119] The reaction temperature for the first reaction was 375°C;

[0120] The reaction temperature of the second reaction was 378°C;

[0121] The reaction temperature of the third reaction was 370°C.

[0122] The other specific process parameters are the same as those in Example 1.

[0123] The nitrogen mass fraction in the reaction effluent I in this example is 9 μg·g -1 , the total aromatic saturation rate is 49.22%.

[0124] The yield and property parameters of the product are shown in Table 3.

[0125] Example 5

[0126] This embodiment is carried out in the same manner as in embodiment 1, except that:

[0127] The temperature of the second reaction was 389°C;

[0128] In this embodiment, the ratio of the sum of the mass of the middle distillate oil I and the tail oil fraction I to the mass of the heavy low-quality wax oil is 0.5267:1; the ratio of the mass of the intermediate material to the mass of the heavy low-quality wax oil is 0.5267:1;

[0129] The reaction temperature of the third reaction is 356°C;

[0130] In the hydrocracking reaction zone II, the protected CAT5 is replaced by refined CAT1, and the loading volume content of refined CAT1 is 30%, and the loading volume content of cracked CAT-7 is 70%;

[0131] In this embodiment, the ratio of the sum of the mass of the middle distillate II and the tail oil fraction II to the mass of the intermediate material is 0.4:1; and the ratio of the mass of the recycled material to the mass of the intermediate material is 0.4:1.

[0132] The other specific process parameters are the same as those in Example 1.

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

[0134] Example 6

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

[0136] In this embodiment, the ratio of the sum of the mass of the middle distillate oil I and the tail oil fraction I to the mass of the heavy low-quality wax oil is 0.8:1; the ratio of the mass of the intermediate material to the mass of the heavy low-quality wax oil is 0.42:1;

[0137] The reaction temperature of the third reaction is 360°C;

[0138] In this embodiment, the ratio of the sum of the mass of the middle distillate II and the tail oil fraction II to the mass of the intermediate material is 0.6:1; and the ratio of the mass of the recycled material to the mass of the intermediate material is 0.6:1.

[0139] The remaining process parameters are the same as those in Example 1.

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

[0141] Example 7

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

[0143] The reaction temperature of the first reaction was 384°C;

[0144] The reaction temperature of the second reaction was 394°C;

[0145] In this embodiment, the ratio of the sum of the mass of the middle distillate oil I and the tail oil fraction I to the mass of the heavy low-quality wax oil is 0.4:1; the ratio of the mass of the intermediate material to the mass of the heavy low-quality wax oil is 0.4:1;

[0146] The reaction temperature of the third reaction is 357°C;

[0147] In this embodiment, the ratio of the sum of the mass of the middle distillate II and the tail oil fraction II to the mass of the intermediate material is 0.6:1; and the ratio of the mass of the recycled material to the mass of the intermediate material is 0.6:1.

[0148] The remaining process parameters are the same as those in Example 1.

[0149] The nitrogen mass fraction in the reaction effluent I in this embodiment is 11 μg·g -1 , the total aromatic saturation rate is 47.81%.

[0150] The yield and property parameters of the product are shown in Table 3.

[0151] Example 8

[0152] This embodiment is carried out in the same manner as in embodiment 1, except that:

[0153] The reaction temperature of the second reaction is 370°C;

[0154] The reaction temperature of the third reaction is 380°C;

[0155] In this embodiment, the ratio of the sum of the mass of the middle distillate II and the tail oil fraction II to the mass of the intermediate material is 0.2:1; and the ratio of the mass of the recycled material to the mass of the intermediate material is 0.2:1.

[0156] The remaining process parameters are the same as those in Example 1.

[0157] The yield and property parameters of the product are shown in Table 3.

[0158] Comparative Example 1

[0159] (1) introducing the heavy low-quality wax oil into the hydrotreating reaction zone filled with a hydrotreating catalyst to carry out a first reaction to obtain a reaction effluent I;

[0160] (2) introducing the reaction effluent I into the hydrocracking reaction zone I filled with a hydrocracking catalyst I to carry out a second reaction to obtain a reaction effluent II; separating the reaction effluent II to obtain a light naphtha fraction I, a heavy naphtha fraction I, a middle distillate oil I, and a tail oil fraction I;

[0161] The specific process parameters are shown in Table 2, and the yield and property parameters of the product are shown in Table 3.

[0162] Comparative Example 2

[0163] This comparative example was carried out in the same manner as in Example 1, except that:

[0164] The reaction temperature of the first reaction was 384°C;

[0165] The reaction temperature of the second reaction was 396°C;

[0166] In the hydrocracking reaction zone I, an equal volume of cracking CAT7 was replaced by cracking CAT8;

[0167] In this embodiment, the ratio of the sum of the mass of the middle distillate oil I and the tail oil fraction I to the mass of the heavy low-quality wax oil is 0.645:1; the ratio of the mass of the intermediate material to the mass of the heavy low-quality wax oil is 0.645:1;

[0168] The reaction temperature of the third reaction is 367°C;

[0169] In this embodiment, the ratio of the sum of the mass of the middle distillate II and the tail oil fraction II to the mass of the intermediate material is 0.6:1; and the ratio of the mass of the recycled material to the mass of the intermediate material is 0.6:1.

[0170] The remaining process parameters are the same as those in Example 1.

[0171] The nitrogen mass fraction in the reaction effluent I in this embodiment is 11 μg·g -1 , the total aromatic saturation rate is 47.81%.

[0172] The yield and property parameters of the product are shown in Table 3.

[0173] Table 2

[0174]

[0175]

[0176] Note: 1. Protection CAT2+Protection CAT3+Protection CAT4+Protection CAT5+Demetallized CAT6+Refined CAT1 means that according to the direction of liquid material flow, Protection CAT2, Protection CAT3, Protection CAT4, Protection CAT5, Demetallized CAT6 and Refined CAT1 are loaded in sequence;

[0177] 2. Protection CAT5 + cracking CAT7 means that protection CAT5 and cracking CAT7 are loaded in sequence according to the direction of liquid material flow.

[0178] Table 3

[0179]

[0180] From the data in Table 2 and Table 3, we can see that:

[0181] In Examples 1 to 3 and 6, when the weight ratio of the active metal components, calculated as oxides, in the hydrorefining catalyst to the hydrocracking catalyst I was controlled to be 1.35-1.60:1, heavy naphtha with a yield of 69% or more and an aromatic latent content of 48 wt% or more was obtained, which can be used as a high-quality reforming material.

[0182] In Example 4, the reaction temperature in the hydrotreating reaction zone was lowered to 375° C., resulting in a total aromatic saturation ratio of 41.20% in the reaction effluent I, and a corresponding refined oil nitrogen content of 26 μg / g. Due to the reduced aromatic saturation ratio in the hydrotreating reaction zone, it was necessary to significantly increase the operating temperature in the hydrocracking reaction zone I to compensate for the reduced aromatic saturation ratio in order to obtain a higher heavy naphtha product yield. However, lowering the total aromatic saturation ratio in the hydrotreating reaction zone would result in an increase in the refined oil nitrogen content, which would cause organic nitrogen poisoning of the catalyst in the hydrocracking reaction zone I, hindering long-term operation of the device.

[0183] In Example 5, the hydroprotected catalyst CAT5 was replaced with the hydrorefining catalyst CAT1 in the hydrocracking reaction zone II, and the loading volume ratio of the hydrocracking catalyst CAT7 was significantly reduced, so that its loading volume content ratio was less than 72%. This would cause the material entering the hydrocracking reaction zone II to be oversaturated, thereby reducing the aromatics potential content of the target product heavy naphtha, increasing the reaction hydrogen consumption, and deteriorating the process economy.

[0184] In Example 7, the reaction temperature in hydrocracking reaction zone I was significantly increased to 394°C to achieve deep conversion of the heavy, low-quality feedstock. The ratio of the combined mass of middle distillate I and tail oil fraction I to the heavy, low-quality wax oil was 0.4:1. However, excessively high hydrocracking reaction severity not only shortens the unit's operating cycle but also increases the yields of C1-C4 gas and light naphtha, while reducing the yield of the target heavy naphtha product.

[0185] In Example 8, the reaction temperature in hydrocracking reaction zone II was increased to reduce the flow rate of the recycle material in hydrocracking reaction zone II, thereby controlling the ratio of the recycle material to the intermediate material to be 0.2:1. However, increasing the operating temperature in hydrocracking reaction zone II intensifies the secondary hydrocracking reaction, resulting in increased yields of C1-C4 gas and light naphtha, and reduced selectivity for the target product, heavy naphtha.

[0186] In Comparative Example 1, under the single-stage hydrocracking process, the liquid hourly space velocity is 1.1h -1 Even at a cracking reaction temperature of 410°C, it is still difficult to achieve complete conversion of heavy and inferior wax oil raw materials. The yield of fractions above 175°C is still as high as 10.0%, which cannot meet the requirement of producing more chemical raw materials from heavy and inferior wax oil.

[0187] In Comparative Example 2, the hydrocracking catalyst CAT8 was used in place of the hydrocracking catalyst CAT7 in the hydrocracking reaction zone I, so that the ratio of the active metal component content in the hydrorefining catalyst to that in the hydrocracking catalyst I was not within the range of 1.35-1.60:1. This, on the one hand, resulted in a reduction in the number of metal active centers in the hydrocracking catalyst and a decrease in the saturation conversion capacity of aromatics. On the other hand, the reduction in the number of cracking centers resulted in a deterioration in the conversion capacity of heavy and inferior wax oil feedstocks, making the severity of the hydrocracking reaction zone I high, with a reaction temperature of 396°C, which is not conducive to the long-term operation of the device. In addition, the reaction at high temperature will lead to an increase in the yield of C1-C4 gas and light naphtha products, and a deterioration in the selectivity of the heavy naphtha product.

[0188] 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 hydrocracking method for producing more chemical raw materials, characterized in that: The method is carried out in a device containing a hydrofining reaction zone and a hydrocracking reaction zone, wherein the hydrocracking reaction zone contains a hydrocracking reaction zone I and a hydrocracking reaction zone II. The method comprises: (1) introducing the heavy low-quality wax oil into the hydrorefining reaction zone filled with a hydrorefining catalyst to carry out a first reaction to obtain a reaction effluent I; controlling the conditions of the first reaction so that the total aromatic saturation rate in the reaction effluent I is 43%-60%; (2) introducing the reaction effluent I into the hydrocracking reaction zone I filled with a hydrocracking catalyst I to carry out a second reaction to obtain a reaction effluent II; separating the reaction effluent II to obtain a light naphtha fraction I, a heavy naphtha fraction I, an intermediate distillate oil I, and a tail oil fraction I; controlling the conditions of the second reaction so that the ratio of the sum of the masses of the intermediate distillate oil I and the tail oil fraction I to the mass of the heavy inferior wax oil is 0.6-0.8:1; (3) introducing the intermediate material into the hydrocracking reaction zone II filled with a hydrocracking catalyst II to carry out a third reaction to obtain a reaction effluent III; and separating the reaction effluent III to obtain a light naphtha fraction II, a heavy naphtha fraction II, an intermediate distillate II, and a tail oil fraction II; and controlling the conditions of the third reaction so that the ratio of the sum of the mass of the intermediate distillate II and the tail oil fraction II to the mass of the intermediate material is 0.4-0.6:1; (4) circulating the recycled material to the hydrocracking reaction zone II to carry out the third reaction; The 95% distillation temperature of the heavy low-quality wax oil according to ASTM D-1160 is 580° C. to 700° C., the nitrogen content is 1800 μg / g to 3500 μg / g, and the sum of the content of two-ring or higher cycloalkanes and two-ring or higher aromatic hydrocarbons is 50 wt % to 80 wt %; The hydrorefining catalyst contains a carrier I and an active metal component I supported on the carrier I, and the hydrocracking catalyst I 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 1.35-1.60:1; The intermediate material is selected from at least one of the middle distillate oil I and the tail oil fraction I; the recycled material is selected from at least one of the middle distillate oil II and the tail oil fraction II.

2. The method according to claim 1, wherein In step (2), in the hydrocracking catalyst I, the carrier II contains a heat-resistant inorganic oxide I and an acidic component I, the heat-resistant inorganic oxide I is selected from at least one of silicon oxide and aluminum oxide, and the acidic component I contains a Y-type molecular sieve; the active metal component II 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 I, 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%.

3. The method according to claim 2, wherein: Based on the total weight of the carrier II, the content of the acidic component I is 45 wt%-75 wt%.

4. The method according to any one of claims 1 to 3, wherein: In step (3), the hydrocracking catalyst II contains a carrier III and an active metal component III supported on the carrier III; the carrier III contains a heat-resistant inorganic oxide II and an acidic component II, the heat-resistant inorganic oxide II is selected from at least one of silicon oxide and aluminum oxide, and the acidic component II 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 II, 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%.

5. The method according to claim 4, wherein In step (2) and step (3), the content of the Y-type molecular sieve in the hydrocracking catalyst I is 0-25 wt% higher than the content of the Y-type molecular sieve in the hydrocracking catalyst II.

6. The method according to any one of claims 1 to 3, wherein: In step (1), in the hydrorefining catalyst, 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.

7. The method according to claim 6, wherein: In step (1), in the hydrorefining catalyst, 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 a combination of molybdenum and tungsten.

8. The method according to claim 7, wherein: In step (1), based on the total weight of the hydrorefining catalyst, 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%.

9. The method according to claim 6, wherein: In step (1), in the hydrorefining catalyst, 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.

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

1.

11. The method according to any one of claims 1 to 3, wherein: In step (1), in the hydrorefining reaction zone, 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.

12. The method according to claim 11, wherein In step (1), based on the total volume of the catalyst in the hydrorefining reaction zone, the loading volume content of the hydrogenation protection catalyst is 5%-25%, the loading volume content of the hydrodemetallization catalyst is 5%-15%, and the loading volume content of the hydrorefining catalyst is 60%-90%.

13. The method according to any one of claims 1 to 3, wherein: In step (3), in the hydrocracking reaction zone II, a hydrogenation protection catalyst is loaded upstream of the hydrocracking catalyst II, and the loading volume content of the hydrocracking catalyst II is 75%-92% based on the total volume of the catalyst in the hydrocracking reaction zone II.

14. The method according to claim 13, wherein In step (1) and step (3), 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 calculated as oxide is 0.1 wt% to 15 wt% based on the total weight of the hydrogenation protected catalyst.

15. The method according to claim 14, 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.

16. The method according to claim 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 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.

17. The method according to claim 16, 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.

18. The method according to any one of claims 1 to 3, wherein: In step (1), the conditions of the first reaction include: hydrogen partial pressure of 14.0 MPa-20.0 MPa, reaction temperature of 280°C-420°C, liquid hourly space velocity of 0.5 h -1 -6h -1 , the hydrogen-to-oil volume ratio is 300-2000.

19. The method according to any one of claims 1 to 3, wherein: In step (2) and step (3), the conditions of the second reaction and the third reaction independently 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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