Hydrocracking method for increasing yield of chemical raw materials

Abstract

The invention relates to the technical field of heavy inferior wax oil processing, and discloses a hydrocracking method for producing high-yield chemical raw materials. The method comprises the following steps: heavy inferior wax oil is introduced into a hydrofining reaction zone for a first reaction, and a reaction effluent I is obtained; the reaction effluent I is introduced into a hydrocracking reaction zone I for a second reaction, a reaction effluent II is obtained, and a light naphtha fraction I, a heavy naphtha fraction I, middle distillate oil I and a tail oil fraction I are obtained; the intermediate material is introduced into a hydrocracking reaction zone II for a third reaction, a reaction effluent III is obtained, and a light naphtha fraction II, a heavy naphtha fraction II, intermediate distillate oil II and a tail oil fraction II are obtained; and circulating the circulating material to the hydrocracking reaction zone II for a third reaction. By adopting the method provided by the invention, the heavy inferior wax oil raw material can be converted into the chemical raw material in a maximum proportion.

Description

Technical Field

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

[0002] In recent years, with the continuous development of the international energy and chemical industries, crude oil production has increased year by year. However, as a non-renewable oil resource, with the increase in production, the supply of high-quality crude oil and conventional crude oil has decreased year by year and the price has risen; at the same time, the supply of heavy and inferior crude oil has increased year by year and the price is relatively low. Although the processing of heavy and inferior crude oil is difficult and costly, by selecting appropriate refining technology and product solutions, refineries can also obtain higher economic benefits by processing heavy and inferior crude oil with low prices and sufficient supply.

[0003] 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.

[0004] 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.

[0005] 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.

[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 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.

[0007] 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.

[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 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.

[0010] 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.

[0011] 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.

[0012] 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.

[0013] However, there are mainly the following two 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 it is difficult to match the processing needs of low-quality raw materials; on the other hand, existing hydrocracking products mainly focus on processing conventional raw materials to produce clean fuel oil (diesel and jet fuel) and some chemical raw materials, 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 the heavy and inferior wax oil raw material products and enhance their value 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 route in the prior art, and to provide a flexible and high-yield heavy and inferior wax oil hydrocracking method for chemical raw materials.

[0017] In order to achieve the above object, the present invention provides a hydrocracking method for producing more chemical raw materials, which 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, and 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, an intermediate 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, an intermediate distillate II, and a tail oil fraction II;

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

[0022] 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 %;

[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 circulating 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 hydrorefining reaction, then introduces the obtained reaction effluent into a hydrocracking reaction zone I for hydrocracking reaction, partially introduces the obtained reaction effluent into a hydrocracking reaction zone II for further hydrocracking reaction, and circulates part of the reaction effluent to the hydrocracking reaction zone II, and simultaneously controls the weight ratio of the metal active components contained in the hydrorefining catalyst I and the hydrocracking catalyst I, so that the heavy low-quality wax oil raw material can be converted into a chemical raw material at a maximum ratio. DETAILED DESCRIPTION

[0026] 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.

[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 chain alkanes, cycloalkanes and aromatic hydrocarbons, and the chain 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 95wt% 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 catalyst pore size distribution calculation method (nitrogen desorption isotherm calculation method) of SH / T0572-1993, and the pore volume is tested with reference to the zeolite specific surface area and micropore volume determination method in the catalyst of NB / SH / T0571-2021.

[0033] 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 of NB / SH / T0571-2021 and the method for measuring surface area of ​​catalysts and adsorbents of GB / T5816-1995.

[0034] As mentioned above, the present invention provides a hydrocracking method for producing more chemical raw materials, which 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, and 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, an intermediate 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, an intermediate distillate II, and a tail oil fraction II;

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

[0039] 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 %;

[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 circulating material is selected from at least one of the middle distillate oil II and the tail oil fraction II.

[0042] The inventors of the present invention discovered during the course of research that due to the high content of sulfur and nitrogen impurities in the heavy and inferior wax oil raw materials, and 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 the heavy and inferior wax oil raw materials; on the other hand, the carbon number and condensation degree of aromatic hydrocarbons in the heavy and inferior wax oil raw materials are high, and deep hydrogenation saturation is difficult. Usually, in the hydrorefining reaction of heavy and inferior wax oil raw materials, when the nitrogen content in the feed is removed to ≯20μg / g, there is still a high proportion of aromatics in the refined oil that have not undergone saturation reaction. In order to ensure that the aromatic compounds in the hydrocracking reaction can meet the reaction requirements of ring-opening cracking, it is usually necessary for the hydrocracking catalyst 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 that can undergo ring-opening cracking; in addition, when heavy and inferior wax oil raw materials are used to produce heavy naphtha as reforming material, excessively high active metal component content of 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 resulting in excessive consumption of hydrogen and increased catalyst costs, but also unreasonable process economy. Therefore, according to the processing requirements of heavy low-quality 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, the hydrogenation saturation of aromatics, especially polycyclic aromatics, can be achieved, which can slow down the deactivation of the cracking catalyst and extend the operation cycle of the device, and can also 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 inferior wax oil is 0.6-0.8:1. The inventors of the present invention have found 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 ratio of the heavy inferior wax oil is controlled below 0.6:1, due to the insufficient conversion ratio of the hydrocracking reaction zone I, the raw material ratio entering the hydrocracking reaction zone II is high and the feed property is poor, 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 reactor investment; and 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 ratio of the heavy inferior wax oil is controlled above 0.8:1, on the one hand, it will cause a sharp increase in the severity of the cracking reaction and shorten the operation cycle of the device, and secondly, at an excessively high reaction temperature, the proportion of the secondary cracking reaction will increase, so that the yield of the product dry gas and liquefied gas will increase, making the selectivity of the reaction process unreasonable. When the mass ratio of the sum of the mass fractions of the intermediate distillate oil I and the tail oil distillate oil I to the mass of the heavy inferior wax oil is controlled within the range of 0.6-0.8:1, the operation 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, so that the reactor investment cost and operating cost are reduced, and the process economy is 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, since the intermediate material is in a low-sulfur, low-nitrogen reaction environment, the reaction conversion depth is high. 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 secondary cracking ratio increases, and the yield of the product dry gas and liquefied gas increases accordingly, and the selectivity of the target product decreases; and 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 increased accordingly, and the energy consumption of the device operation will be greatly increased. When the ratio of the sum of the masses of the intermediate distillate oil II and the tail oil fraction 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 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 step (2) and step (3), the content of the Y-type molecular sieve in the hydrocracking catalyst I is 0-25wt% higher than the content of the Y-type molecular sieve in the hydrocracking catalyst II. The inventors of the present invention have found that in this preferred case, not only the cracking ability of the heavy low-quality wax oil feedstock can be improved, the reaction severity can be reduced, but also the selectivity of converting the heavy low-quality wax oil into the heavy naphtha fraction can be improved.

[0050] Preferably, in step (1), in the hydrotreating 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 based on the total weight of the hydrotreating catalyst, the content of the active metal component I in terms of oxide is 35 wt%-55 wt%.

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

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

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

[0054] Further, in step (1), in the hydrotreating 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 hydrotreating reaction zone, 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.

[0056] Further preferably, in step (1), in the hydrofining reaction zone, according to the direction of flow of the liquid phase material, the hydroprotected catalyst is a combination of at least four hydroprotected catalysts with increasing active metal component contents. The inventors of the present invention have found that under this preferred condition, the reaction temperature ladder and the refining reaction heat can be reasonably matched while effectively removing metal impurities from heavy low-quality wax oil, thereby extending the operation cycle of the demetallization catalyst.

[0057] Particularly preferably, in step (1), based on the total volume of the catalyst in the hydrotreating 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 hydrotreating catalyst is 60%-90%.

[0058] According to another preferred embodiment, 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. The inventors of the present invention have found that under this preferred embodiment, impurities or polycyclic aromatic hydrocarbons from the circulating material or device system can be effectively removed, thereby achieving the goal of slowing down the deactivation rate of the hydrocracking catalyst II.

[0059] Preferably, in step (1) and step (3), the hydrogenation protection 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 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.

[0060] More 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.

[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 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.

[0062] 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.

[0063] According to a preferred embodiment, in step (1), the conditions of the first reaction include: a hydrogen partial pressure of 14.0 MPa-20.0 MPa, a reaction temperature of 280°C-420°C, a liquid hourly space velocity of 0.5 h -1-6h -1 , the volume ratio of hydrogen to oil 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: a hydrogen partial pressure of 6.0 MPa-20.0 MPa, a reaction temperature of 290°C-420°C, a liquid hourly space velocity of 0.3 h -1 -5h -1 , the volume ratio of hydrogen to oil 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 of the hydrocracking reaction zone II includes at least one of the middle distillate oil and the tail oil fraction from the hydrocracking reaction zone I and the hydrocracking reaction zone II, wherein, in the case of producing only naphtha products, the feed of the hydrocracking reaction zone II includes the middle distillate oil and the tail oil fraction from the hydrocracking reaction zone I and the hydrocracking reaction zone II; in the case of producing naphtha and middle distillate oil at the same time, the feed of the hydrocracking reaction zone II includes the tail oil fraction from the hydrocracking reaction zone I and the hydrocracking reaction zone II.

[0068] The present invention will be described in detail below by way of 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 1000 g of pseudo-boehmite (purchased from Sinopec Catalyst Changling Branch, with a dry basis of 0.73 and a specific surface area of ​​300 m 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;

[0072] 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;

[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 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.

[0074] In the following example,

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

[0077] The yield of heavy naphtha fraction (initial distillation point is 65°C, final distillation point is 165°C-175°C) = (mass of heavy naphtha fraction I + mass of heavy naphtha fraction II) / mass of heavy inferior wax oil feedstock × 100%;

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

[0079] raw material:

[0080] Hydrotreating catalysts:

[0081] 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 71.68m 2 / g, and the ratio to 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 RG-201, carrier III is alumina, calculated as oxide, the molybdenum content is 1.2wt%, the nickel content is 0.3wt%, the linear average particle size is 10mm, and the specific surface area is 95m 2 / g, bulk density is 0.56g / cm 3 ;

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

[0086] Protection CAT5: Brand 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: RAM-100, carrier IV is alumina, calculated as oxide, molybdenum content is 7.5wt%, nickel content is 1.3wt%, linear average particle size is 1.8mm, 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 27.0wt% and a nickel content of 2.7wt% based on oxides, and the balance being carrier II; based on the total weight of the carrier, the acidic component (all Y-type molecular sieves) is 65wt%, and the balance is alumina;

[0091] Cracking CAT8: The brand is RHC-210F. Calculated as oxide, the content of molybdenum is 15.5wt%, the content of nickel 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, an intermediate 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, an intermediate distillate II, and a tail oil fraction II;

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

[0100] The specific process condition 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 in this embodiment:

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

[0104] 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 in this embodiment 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 is 364°C;

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

[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] 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 in this embodiment 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 oil II and the tail oil fraction II to the mass of the intermediate material is 0.4:1; the ratio of the mass of the circulating 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 in this embodiment:

[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 in this embodiment:

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

[0128] 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 in this embodiment 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 oil II and the tail oil fraction II to the mass of the intermediate material is 0.4:1; the ratio of the mass of the circulating 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 in this embodiment:

[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 oil II and the tail oil fraction II to the mass of the intermediate material is 0.6:1; the ratio of the mass of the circulating 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 in this embodiment:

[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 oil II and the tail oil fraction II to the mass of the intermediate material is 0.6:1; the ratio of the mass of the circulating 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 example 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 in this embodiment:

[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 oil II and the tail oil fraction II to the mass of the intermediate material is 0.2:1; 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, an intermediate distillate oil I and a tail oil fraction I;

[0161] The specific process condition 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 in this example:

[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 is replaced by cracking CAT8;

[0167] 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 in this embodiment 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 oil II and the tail oil fraction II to the mass of the intermediate material is 0.6:1; the ratio of the mass of the circulating 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 example 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 flow direction of liquid materials.

[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 in the hydrorefining catalyst and the hydrocracking catalyst I in terms of oxides is controlled to be 1.35-1.60:1, heavy naphtha with a yield of more than 69% and an aromatic potential content of more than 48wt% can be obtained, which can be used as a high-quality reforming material;

[0182] In Example 4, the reaction temperature in the hydrofining reaction zone is reduced to 375° C., so that the total aromatic saturation rate in the reaction effluent I is 41.20%, and the corresponding refined oil nitrogen content is 26 μg / g. Since the aromatic saturation rate in the hydrofining reaction zone is reduced, on the one hand, it is necessary to significantly increase the operating temperature in the hydrocracking reaction zone I to compensate in order to obtain a higher heavy naphtha product yield; however, reducing the total aromatic saturation rate in the hydrofining reaction zone will lead to an increase in the refined oil nitrogen content, which will cause the catalyst in the hydrocracking reaction zone I to be poisoned by organic nitrogen, which is not conducive to the long-term operation of the device;

[0183] In Example 5, the hydroprotection catalyst CAT5 is replaced with the hydrofining catalyst CAT1 in the hydrocracking reaction zone II, and the loading volume ratio of the hydrocracking catalyst CAT7 is greatly reduced, so that its loading volume content ratio is less than 72%, which will cause the material entering the hydrocracking reaction zone II to be oversaturated, thereby causing the aromatics potential content of the target product heavy naphtha to decrease, the reaction hydrogen consumption to increase, and the process economy to deteriorate;

[0184] In Example 7, the reaction temperature of the hydrocracking reaction zone I was greatly increased to 394°C to achieve deep conversion of heavy and inferior raw materials, and the ratio of the sum of the mass of the middle distillate oil I and the tail oil fraction I to the heavy and inferior wax oil was 0.4:1. However, under the excessively high severity of the hydrocracking reaction, not only will the operating cycle of the device be compressed, but also the yield of C1-C4 gas and light naphtha will increase, and the yield of the target product heavy naphtha will decrease;

[0185] In Example 8, the reaction temperature in the hydrocracking reaction zone II is increased to reduce the flow rate of the circulating material in the hydrocracking reaction zone II, and the ratio of the circulating material to the intermediate material is controlled at 0.2: 1. However, increasing the operating temperature in the hydrocracking reaction zone II will lead to an intensification of the secondary hydrocracking reaction, resulting in an increase in the yield of C1-C4 gas and light naphtha, and a deterioration in the selectivity of 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 , under the condition of cracking reaction temperature of 410℃, it is still difficult to achieve the complete conversion of heavy and inferior wax oil raw materials, and the yield of fractions >175℃ 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 is used to replace the hydrocracking catalyst CAT7 in the hydrocracking reaction zone I, so that the content ratio of the active metal components in the hydrorefining catalyst and the hydrocracking catalyst I is not in the range of 1.35-1.60:1. On the one hand, this leads to a decrease in the number of metal active centers of the hydrocracking catalyst and a decrease in the saturated conversion capacity of aromatics. On the other hand, the reduction in the number of cracking centers leads to a deterioration in the conversion capacity of heavy and inferior wax oil feedstocks, making the severity of the hydrocracking reaction zone I high, and the reaction temperature is 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 product heavy naphtha.

[0188] 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 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 hydrotreating reaction zone filled with a hydrotreating catalyst to carry out a first reaction to obtain a reaction effluent I; (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; (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; (4) circulating the circulating 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-700°C, the nitrogen content is 1800μg / g-3500μg / g, and the sum of the content of cycloalkanes with two or more rings and aromatics with two or more rings is 50wt%-80wt%; 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 circulating 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 (1), the conditions of the first reaction are controlled so that the total aromatic saturation rate in the reaction effluent I is 43%-60%.

3. The method according to claim 1 or 2, wherein: In step (2), 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 low-quality wax oil is 0.6-0.8:

1.

4. The method according to any one of claims 1 to 3, wherein: In step (3), 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.

5. The method according to any one of claims 1 to 4, 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%; Preferably, based on the total weight of the carrier II, the content of the acidic component I is 45 wt%-75 wt%.

6. The method according to any one of claims 1 to 5, 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%.

7. The method according to claim 6, 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.

8. The method according to any one of claims 1 to 7, 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 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; Preferably, in step (1), in the hydrotreating 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; Preferably, in step (1), based on the total weight of the hydrotreating catalyst, 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%.

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

1.

10. The method according to any one of claims 1 to 9, wherein: In step (1), in the hydrofining reaction zone, a hydroprotection catalyst and a hydrodemetallization catalyst are sequentially loaded upstream of the hydrofining catalyst in the direction of flow of the liquid phase material; Preferably, in step (1), based on the total volume of the catalyst in the hydrotreating 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 hydrotreating catalyst is 60%-90%.

11. The method according to any one of claims 1 to 10, 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.

12. The method according to claim 11, wherein: In step (1) and step (3), the hydrogenation protection 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 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.

13. The method according to claim 10, 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-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.

14. The method according to any one of claims 1 to 13, wherein: The method according to any one of claims 1 to 10, wherein in step (1), the conditions of the first reaction include: a hydrogen partial pressure of 14.0 MPa-20.0 MPa, a reaction temperature of 280° C.-420° C., a liquid hourly space velocity of 0.5 h -1 -6h -1 , the volume ratio of hydrogen to oil is 300-2000.

15. The method according to any one of claims 1 to 14, 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°C-420°C, liquid hourly space velocity of 0.3h -1 -5h -1 , the volume ratio of hydrogen to oil is 300-2000.

Images