A processing method for producing chemical raw materials from vacuum residue

Abstract

The present invention discloses a processing method for producing chemical raw materials from vacuum residue. The method includes: mixing the vacuum residue raw material with hydrogen and entering a fluidized bed hydrocracking reaction zone for hydrothermal cracking reaction, and obtaining fluidized bed light distillate oil through separation and fractionation; wherein, the mass content of bicyclic aromatic hydrocarbons in the fluidized bed light distillate oil is 0.1% to 1.0%; in the presence of hydrogen, the fluidized bed light distillate oil enters a first hydrocracking reaction zone to obtain a first hydrocracking product; wherein, the mass content of C7+ normal paraffin in the first hydrocracking product is controlled to be 0.1% to 5.0%; in the presence of hydrogen, the first hydrocracking product enters a second hydrocracking reaction zone to obtain a second hydrocracking product; the second hydrocracking product is separated and fractionated to obtain a gas fraction, light naphtha, and heavy naphtha. This method uses vacuum residue as a raw material, which can greatly improve the quality and yield of chemical raw materials.

Description

Technical Field

[0001] The present invention belongs to the field of heavy oil processing, and particularly relates to a processing method for combined production of chemical raw materials by ebullated bed residue hydrotreating and hydrocracking, especially a processing method for producing high-quality chemical raw materials from inferior heavy oil. Background Art

[0002] In recent years, with the gradual reduction of light crude oil resources and the continuous increase of its price, processing inferior heavy oil with rich reserves, wide sources and low price has become a global trend. At the same time, the market demand for light oil products is increasing continuously, and the environmental protection regulations are becoming increasingly strict on the quality requirements of oil products. The above situation forces refineries to seriously face the worldwide technical problem of deep processing of inferior heavy oil. The ebullated bed residue hydrotreating technology can be used to process high-sulfur, high-carbon residue and high-metal heavy crude oil, and has the advantages of uniform temperature in the reactor, long operation cycle and flexible unit operation. It can solve the problems of low space velocity, fast catalyst deactivation and large system pressure drop in fixed bed residue hydrotreating units, and has obvious advantages.

[0003] CN201580070326.4 discloses a method for preparing LPG and BTX, including: a) subjecting a mixed hydrocarbon stream to a first hydrocracking in the presence of a first hydrocracking catalyst to prepare a first hydrocracking product stream; b) separating the first hydrocracking product stream to provide at least one light hydrocarbon stream containing at least C2 and C3 hydrocarbons, an intermediate hydrocarbon stream composed of C4 and / or C5 hydrocarbons, and a heavy hydrocarbon stream containing at least C6+ hydrocarbons, and c) subjecting the heavy hydrocarbon stream to a second hydrocracking in the presence of a second hydrocracking catalyst to prepare a second hydrocracking product stream containing BTX, wherein the second hydrocracking is more severe than the first hydrocracking, d) wherein, in the presence of a C4 hydrocracking catalyst, at least part of the intermediate hydrocarbon stream is subjected to C4 hydrocracking to prepare a C4 hydrocracking product stream, and the C4 hydrocracking is optimized for converting C4 hydrocarbons into C3 hydrocarbons.

[0004] CN201480037272.7 discloses a method for producing light olefin hydrocarbon compounds from a hydrocarbon raw material, including the following steps: (a) feeding the hydrocarbon raw material to a reaction zone for ring opening; (b) separating the reaction product generated from the reaction zone into an overhead stream and a side stream; (c) feeding the side stream from (b) to a gasoline hydrocracker (GHC) unit; (d) separating the reaction product of the GHC in step (c) into an overhead stream containing hydrogen, methane, ethane and liquefied petroleum gas and a stream containing aromatic hydrocarbon compounds and a small amount of hydrogen and non-aromatic hydrocarbon compounds; (e) feeding the overhead stream from the gasoline hydrocracker (GHC) unit to a steam cracker unit.

[0005] In summary, petroleum hydrocarbons have a complex composition, mainly including alkanes, cycloalkanes and aromatics. Among them, alkanes, especially small-molecule alkanes, are high-quality ethylene raw materials, while cycloalkanes and aromatics are high-quality reforming feeds. ebullated bed residue hydrotreating is a thermal cracking reaction of heavy raw materials in a hydrogen environment, following the free radical reaction mechanism. The products have a high content of n-paraffins and cyclic hydrocarbons. In the prior art, it is impossible to efficiently achieve the conversion effect of "ethylene production for suitable feedstocks and aromatics production for suitable feedstocks" for the ebullated bed residue hydrotreating distillate oil. Therefore, it is of great significance to develop a processing method suitable for producing high-quality chemical raw materials from vacuum residue through ebullated bed hydrogenation and hydrocracking. Summary of the Invention

[0006] Aiming at the problems existing in the prior art, the purpose of the present invention is to provide a processing method for producing chemical raw materials from vacuum residue. This method uses vacuum residue as the raw material and can greatly improve the yield and quality of chemical raw materials.

[0007] The present invention provides a processing method for producing chemical raw materials from vacuum residue, and the method includes:

[0008] (1) Mix the vacuum residue raw material with hydrogen and enter the ebullated bed hydrogenation reaction zone for hydrothermal cracking reaction, and obtain ebullated bed light distillate oil through separation and fractionation; wherein, the mass content of bicyclic aromatics in the ebullated bed light distillate oil is 0.1% - 1.0%;

[0009] (2) In the presence of hydrogen, the ebullated bed light distillate oil obtained in step (1) enters the first hydrocracking reaction zone to selectively crack the n-paraffins in the hydrocarbon oil raw material to obtain the first hydrocracking product; wherein, the mass content of C7 + n-paraffins in the first hydrocracking product is controlled at 0.1% - 5.0%;

[0010] (3) In the presence of hydrogen, the first hydrocracking product enters the second hydrocracking reaction zone to obtain a second hydrocracking product containing monocyclic cyclic hydrocarbons;

[0011] (4) The second hydrocracking product is separated and fractionated to obtain a gas fraction, light naphtha, and heavy naphtha.

[0012] According to the present invention, preferably, the mass content of C7 + n-paraffins in the first hydrocracking product is controlled at 1.0% - 4.0%.

[0013] According to the present invention, in the second hydrocracking product in step (3), the mass ratio of C6 - C8 monocyclic cyclic hydrocarbons to the total cyclic hydrocarbon mass in the ebullated bed light distillate oil is 0.40 - 0.80, preferably 0.48 - 0.60.

[0014] According to the present invention, in step (1), the initial boiling point of the vacuum residue is 420°C to 620°C, preferably 450°C to 550°C; the sulfur mass content is 2% to 10%, preferably 4% to 8%; the nitrogen mass content is 0.2% to 1.0%, preferably 0.3% to 0.5%; and the metal content is 100 mg / kg to 500 mg / kg, preferably 200 mg / kg to 300 mg / kg.

[0015] According to the present invention, in step (1), the reaction conditions in the ebullated bed hydrotreating reaction zone are as follows: the reaction pressure is 10 MPa to 25 MPa, preferably 15 MPa to 20 MPa; the reaction temperature is 350°C to 500°C, preferably 400°C to 450°C; the hydrogen-oil volume ratio is 100:1 to 2000:1, preferably 300:1 to 1000:1; and the volume hourly space velocity is 0.1 h -1 ~1.5 h -1 Preferably 0.2 h -1 ~1.0 h -1 .

[0016] According to the present invention, in step (1), the conversion rate of the vacuum residue feedstock in the ebullated bed hydrotreating reaction zone is controlled to be 60% to 90%, preferably 70% to 80%; the conversion rate is defined as the sum of the mass percentages of the gas fraction, light distillate oil, diesel, and wax oil in the ebullated bed hydrotreating product relative to the fresh feedstock.

[0017] According to the present invention, in step (1), the initial boiling point of the ebullated bed light distillate oil is 50°C to 80°C, preferably 60°C to 70°C, and the final boiling point is 190°C to 240°C, preferably 200°C to 220°C.

[0018] According to the present invention, preferably, the mass content of bicyclic aromatic hydrocarbons in the ebullated bed light distillate oil is 0.2% to 0.6%.

[0019] According to the present invention, the chemical raw materials mainly include ethane, propane, butane, and light naphtha, and may also include heavy naphtha. Among them, heavy naphtha is used as a reforming feedstock to produce BTX, and ethane, propane, butane, and light naphtha are used as raw materials for producing lower olefins. For example, they are used as steam cracking feedstocks to produce ethylene, and propane and butane can also be directly dehydrogenated to produce propylene and butene. Among them, lower olefins refer to olefins with four or fewer carbon atoms, especially ethylene, propylene, and butadiene.

[0020] According to the present invention, in step (2), the first hydrocracking reaction zone is filled with the first hydrocracking catalyst, and in step (3), the second hydrocracking reaction zone is filled with the second hydrocracking catalyst. Among them, the first hydrocracking catalyst can be one or more catalysts, and the second hydrocracking catalyst can be one or more catalysts.

[0021] According to the present invention, in step (2), the first hydrocracking catalyst comprises an active metal component and a support; the support comprises a molecular sieve having a selectivity for cracking n-paraffins, preferably selected from one or more of ZSM-5 molecular sieve, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35 and ZSM-38 molecular sieves, and more preferably ZSM-5 molecular sieve. The SiO2 / Al2O3 molar ratio of the ZSM-5 molecular sieve is 20 to 60. The support may further comprise a binder. Preferably, the binder is alumina. The active metal component comprises at least one of metals of Group VIB and Group VIII. The Group VIB metal is preferably molybdenum and / or tungsten, and the Group VIII metal is preferably cobalt and / or nickel.

[0022] According to the present invention, in step (2), preferably, in the first hydrocracking catalyst, based on the weight of the catalyst, the content of the Group VIB metal (calculated as the oxide) is 5.0% to 15.0%, the content of the Group VIII metal (calculated as the oxide) is 2.0% to 5.0%, and the content of the support is 80.0% to 93.0%.

[0023] According to the present invention, in step (2), preferably, in the support of the first hydrocracking catalyst, based on the weight of the support, the content of the binder is 8% to 60%, and the content of the molecular sieve is 40% to 92%.

[0024] According to the present invention, in step (2), the specific surface area of the first hydrocracking catalyst is 200 to 400 m 2 2 / g, and the pore volume is 0.25 to 0.45 mL / g.

[0025] According to the present invention, the preparation method of the first hydrocracking catalyst in step (2) can be prepared according to conventional methods in the art. The preparation method includes the preparation of the support and the loading of the active metal component. The preparation process of the support is as follows: the shape-selective cracking molecular sieve and the binder are mechanically mixed, formed, and then dried and calcined to make the catalyst support. The drying and calcination of the support can adopt conventional conditions. The drying conditions are: drying at 100°C to 150°C for 1 to 12 hours. The calcination conditions are: calcining at 450°C to 550°C for 2.5 to 6.0 hours.

[0026] According to the present invention, in step (2), in the preparation method of the first hydrocracking catalyst, the method for loading the active metal component is a conventional method, such as kneading method, impregnation method, etc., and the impregnation method is preferably used. The impregnation method can be saturated impregnation method, excess impregnation method or complex impregnation method, that is, the catalyst carrier is impregnated with a solution containing the required active component, and then dried and calcined to obtain the first hydrocracking catalyst. The conditions for drying are: drying at 100°C to 150°C for 1 to 12 hours. The conditions for calcination are: calcining at 450°C to 550°C for 2.5 to 6.0 hours.

[0027] According to the present invention, in step (3), the second hydrocracking catalyst has the function of selectively cracking the side chains of isoparaffins or cyclic hydrocarbons and retaining the monocyclic cyclic hydrocarbons. The second hydrocracking catalyst includes a cracking component, a hydrogenation component and a binder. The second hydrocracking catalyst can be a commercially available product or prepared according to the prior art. The hydrogenation component is at least one of a metal, a metal oxide, and a metal sulfide of the active metal component; the active metal component includes Group VIB and / or Group VIII metals; the active metal component is more preferably at least one of iron, chromium, molybdenum, tungsten, cobalt, and nickel. In the second hydrocracking catalyst, the binder is alumina and / or silica; the cracking component includes an acidic molecular sieve, preferably at least one of Beta zeolite and Y zeolite, and more preferably Beta zeolite.

[0028] According to the present invention, for the second hydrocracking catalyst in step (3), based on the weight of the second hydrocracking catalyst, the content of the hydrogenation component calculated as the oxide is 5 wt% to 40 wt%, preferably 10 wt% to 20 wt%; the content of the cracking component is 20 wt% to 80 wt%, preferably 30 wt% to 70 wt%; the content of the binder is 5 wt% to 75 wt%, preferably 10 wt% to 50 wt%.

[0029] According to the present invention, the preparation method of the second hydrocracking catalyst in step (3) can be prepared according to the conventional methods in the art. The preparation method includes the preparation of the carrier and the loading of the hydrogenation component. The process of preparing the carrier is as follows: the cracking component and the binder are mechanically mixed, formed, and then dried and calcined to make the catalyst carrier. The drying and calcination of the carrier can adopt conventional conditions. The conditions for drying are: drying at 100°C to 150°C for 1 to 12 hours. The conditions for calcination are: calcining at 450°C to 550°C for 2.5 to 6.0 hours.

[0030] According to the present invention, in step (3), in the preparation method of the second hydrocracking catalyst, the method for loading the hydrocracking component is a conventional method, such as kneading method, impregnation method, etc., and the impregnation method is preferred. The impregnation method can be saturated impregnation method, excess impregnation method or complex impregnation method, that is, impregnating the catalyst carrier with a solution containing the required hydrocracking component, and then drying and calcining to obtain the second hydrocracking catalyst. The drying conditions are: drying at 100°C to 150°C for 1 to 12 hours. The calcining conditions are: calcining at 450°C to 550°C for 2.5 to 6.0 hours.

[0031] According to the present invention, in step (2), the reaction conditions of the first hydrocracking reaction are as follows: the reaction pressure is 1.0 to 5.0 MPa, preferably 2.0 to 4.0 MPa.

[0032] According to the present invention, in step (2), the reaction conditions of the first hydrocracking reaction are as follows: the average reaction temperature is 250 to 450°C, preferably 300 to 400°C; the liquid hourly space velocity is 0.1 to 15.0 h -1 , preferably 1.0 to 5.0 h -1 ; the hydrogen-oil volume ratio is 100:1 to 2500:1, preferably 400:1 to 2000:1.

[0033] According to the present invention, in step (3), the reaction conditions of the second hydrocracking reaction are as follows: the reaction pressure is 1.0 to 5.0 MPa, preferably 2.0 to 4.0 MPa.

[0034] According to the present invention, in step (3), the reaction conditions of the second hydrocracking reaction are as follows: the average reaction temperature is 250 to 450°C, preferably 300 to 400°C; the liquid hourly space velocity is 0.1 to 15.0 h -1 , preferably 1.0 to 5.0 h -1 ; the hydrogen-oil volume ratio is 100:1 to 2500:1, preferably 400:1 to 2000:1.

[0035] According to the present invention, preferably, the first hydrocracking reaction zone and the second hydrocracking reaction zone adopt the same pressure.

[0036] According to the present invention, preferably, the second hydrocracking product in step (3) is subjected to supplementary hydrofining. The supplementary hydrofining can be carried out by loading a hydrofining catalyst at the bottom of the first hydrocracking reaction zone, or it can enter a separate hydrofining reaction zone.

[0037] According to the present invention, preferably, the second hydrocracking product in step (3) can also first enter the fractionation system, and the separated heavy naphtha component is subjected to supplementary hydrofining.

[0038] Petroleum hydrocarbons have a complex composition, mainly including alkanes, cycloalkanes, and aromatics. High-quality ethylene raw materials are small-molecule normal alkanes, and reforming raw materials are monocyclic cycloalkanes and aromatics. Through research, the inventor found that by passing the fluidized-bed light distillate oil raw material through the shape-selective cracking of straight-chain alkanes and the selective hydrocracking of long side chains on isohydrocarbons or cyclic hydrocarbons in sequence, monocyclic cyclic hydrocarbons can be retained as much as possible, and small-molecule normal alkanes can be selectively produced, thereby achieving the efficient enrichment of small-molecule normal alkanes in the low-carbon olefin raw material, and at the same time retaining monocyclic cyclic hydrocarbons in heavy naphtha as much as possible to achieve the efficient enrichment of high-quality reforming raw materials. In this way, the yield of chemical raw materials (i.e., low-carbon olefin raw materials and reforming raw materials) and the quality of low-carbon olefin raw materials and reforming raw materials can be greatly improved, thus completing the present invention.

[0039] Compared with the prior art, the present invention has the following beneficial technical effects:

[0040] (1) In the processing method of producing chemical raw materials from vacuum residue of the present invention, an appropriate conversion depth is controlled in the fluidized-bed hydrotreating reaction zone to ensure a high content of normal hydrocarbons in the fluidized-bed hydrotreated light distillate oil. By controlling the aromatic content of the fluidized-bed light distillate oil, the reforming raw material distillation range is broadened, which can not only improve the chemical raw material yield, but also increase the aromatic content in the fluidized-bed light distillate oil. Through hydrocracking, heavy naphtha with a higher aromatic enrichment degree is produced, and at the same time, the ethylene raw material production is increased. Specifically, the fluidized-bed hydrotreated light distillate oil first contacts with the first hydrocracking catalyst to carry out chain-breaking reactions on straight-chain hydrocarbons, and by controlling the C7 normal hydrocarbon content in the shape-selective cracking reaction effluent within a certain range, it is ensured that the straight-chain hydrocarbons are enriched in the light naphtha and gas products after the cracking reaction. Then, the second hydrocracking is carried out to selectively break the chains of isohydrocarbons, so as to realize the efficient separation of alkanes and cyclic hydrocarbons in the fluidized-bed hydrotreated light distillate oil, increase the production of high-quality ethylene cracking feed, and improve the quality of heavy naphtha as the catalytic reforming feed. + The cyclic hydrocarbon enrichment degree in the hydrocracked product light distillate oil is high, and the alkane content is low. Using this as the catalytic reforming raw material, the catalytic reforming unit only needs to adopt two reaction zones of six-membered ring dehydrogenation and five-membered ring isomerization dehydrogenation, cancel the alkane cyclization reaction zone, and greatly reduce the energy consumption of the catalytic reforming unit. At the same time, since the hydrocracking reaction follows the carbocation reaction mechanism, the side-chain breaking reaction of cyclic hydrocarbons above C9 can be selectively carried out, so that the C6-C8 cyclic hydrocarbons in the product have a high enrichment degree, and the BTX yield can be greatly increased after catalytic reforming and aromatics extraction.

[0041] (2) The cyclic hydrocarbon enrichment degree in the hydrocracked product light distillate oil is high, and the alkane content is low. Using this as the catalytic reforming raw material, the catalytic reforming unit only needs to adopt two reaction zones of six-membered ring dehydrogenation and five-membered ring isomerization dehydrogenation, cancel the alkane cyclization reaction zone, and greatly reduce the energy consumption of the catalytic reforming unit. At the same time, since the hydrocracking reaction follows the carbocation reaction mechanism, the side-chain breaking reaction of cyclic hydrocarbons above C9 can be selectively carried out, so that the C6-C8 cyclic hydrocarbons in the product have a high enrichment degree, and the BTX yield can be greatly increased after catalytic reforming and aromatics extraction.

[0042] (4) The present invention selectively converts alkanes in the light fraction of the ebullated bed into small - molecule alkanes. This process consumes a certain amount of hydrogen. However, as the light hydrocarbons are used as raw materials for the ethylene plant, their hydrogen production rate is also high, and the lower the carbon number, the higher the hydrogen production rate. Therefore, most of the hydrogen consumed in the hydrogenation process can be recovered after passing through the ethylene plant. At the same time, as raw materials for ethylene, the light hydrocarbons can significantly increase the yields of ethylene, propylene, and butadiene, and extend the cleaning cycle of the ethylene plant, significantly improving the economic benefits of the plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is a schematic process flow diagram of the process method of the present invention;

[0044] Description of the main reference numerals:

[0045] 1 - vacuum residue, 2 - hydrogen, 3 - ebullated bed hydrogenation reaction zone, 4 - effluent from the ebullated bed hydrogenation reaction, 5 - separator, 6 - gas - phase stream, 7 - liquid - phase stream, 8 - fractionating tower, 9 - gas fraction, 10 - light fraction oil, 11 - diesel oil, 12 - wax oil, 13 - tail oil, 14 - hydrogen, 15 - first hydrocracking reaction zone, 16 - effluent from the first hydrocracking reaction, 17 - second hydrocracking reaction zone, 18 - effluent from the second hydrocracking reaction, 19 - separator, 20 - hydrogen - rich gas in the gas - phase stream, 21 - liquid - phase stream, 22 - fractionating tower, 23 - gas fraction, 24 - light naphtha, 25 - heavy naphtha. DETAILED DESCRIPTION OF THE INVENTION

[0046] The functions and effects of the present invention will be further illustrated by the following examples, but the following examples do not limit the method of the present invention.

[0047] In the present invention, unless otherwise specified, % are all mass fractions.

[0048] The overall volume space velocity in the examples and comparative examples is the ratio of the fresh feed volume to the total volume of the catalyst.

[0049] The method of the present invention, as Figure 1As shown in the figure, it includes: vacuum residue 1 and hydrogen 2 are mixed and enter the ebullated bed hydrotreating reaction zone 3. The ebullated bed hydrotreating reaction effluent 4 obtained enters the separator 5. The separated gas-phase stream 6 is recycled. The liquid-phase stream 7 enters the fractionating tower 8, and gas fractions 9, light distillate oil 10, diesel 11, wax oil 12, and tail oil 13 are fractionated. The light distillate oil 10 and hydrogen 14 are mixed and enter the first hydrocracking reaction zone 15 for the first hydrocracking reaction. The first hydrocracking reaction effluent 16 enters the second hydrocracking reaction zone 17 for the hydrocracking reaction. The second hydrocracking reaction effluent 18 enters the separator 19. The separated gas-phase stream rich in hydrogen gas 20 is recycled. The liquid-phase stream 21 enters the fractionating tower 22, and gas fractions 23, light naphtha 24, and heavy naphtha 25 are fractionated.

[0050] In the present invention, in each example, the first hydrocracking catalyst is represented by Cat-A plus a number, such as Cat-A1, Cat-A2, Cat-A3. The first hydrocracking catalyst is prepared by a conventional active metal saturation impregnation method, and the physicochemical properties of the obtained catalyst are shown in Table 1.

[0051] In the present invention, in each example, the second hydrocracking catalyst is represented by Cat-B plus a number, such as Cat-B1, Cat-B2. The physicochemical properties of the catalyst are shown in Table 2. In each example, the second hydrocracking catalyst is prepared by a conventional active metal saturation impregnation method. Among them, the properties of the Beta zeolite used in Cat-B1 are as follows: the SiO2 / Al2O3 molar ratio is 30, the specific surface area is 350 m 2 / g, and the pore volume is 0.32 cm 3 / g. The properties of the Y zeolite used in Cat-B2 are as follows: the SiO2 / Al2O3 molar ratio is 15, the specific surface area is 400 m 2 / g, and the pore volume is 0.30 cm 3 / g. The physicochemical properties of the obtained catalyst are shown in Table 2.

[0052] In the present invention, in each example, the feedstock oil is vacuum residue, and its main properties are shown in Table 3.

[0053] In the present invention, the ethylene feedstock in each example refers to ethane, propane, butane, and light naphtha obtained in step (3). Ethane, propane, butane, and light naphtha can be directly used as feedstocks for steam cracking to produce ethylene.

[0054] In the present invention, the distillation range of light naphtha is the liquid component with a boiling point less than 60 °C, and the distillation range of heavy naphtha is 60 - 175 °C.

[0055] In the present invention, the yield of ethylene raw materials refers to the mass ratio of ethane, propane, butane, and light naphtha in the hydrocracking product to the fresh hydrocracking raw material (light distillate oil), and the yield of heavy naphtha refers to the mass ratio of heavy naphtha in the hydrocracking product to the fresh hydrocracking raw material (light distillate oil).

[0056] Example 1

[0057] The method of this example adopts the process as Figure 1 follows, including:

[0058] (1) The heavy oil raw material is mixed with hydrogen and enters the ebullated bed hydrotreating reaction zone for hydrothermal cracking reaction. The effluent from the ebullated bed hydrotreating reaction enters the separator. The separated gas-phase stream is recycled, and the liquid-phase stream enters the fractionating tower, where gas fractions, light distillate oil, diesel oil, wax oil, and tail oil are fractionated;

[0059] (2) The light distillate oil obtained in step (1) is mixed with hydrogen and sequentially enters the first hydrocracking reaction zone and the second hydrocracking reaction zone. The first hydrocracking reaction zone is filled with the shape-selective cracking catalyst Cat-A1; the second hydrocracking reaction zone is filled with the hydrocracking catalyst Cat-B1. In step (2), the content of C7 n-paraffins in the effluent from the first hydrocracking reaction is controlled to be 1%. +

[0060] (3) The effluent from the second hydrocracking reaction zone in step (2) is separated into a gas-phase stream and a liquid-phase stream. The gas-phase stream is recycled, and the liquid-phase stream enters the fractionating tower, where gas fractions, light naphtha, and heavy naphtha are fractionated.

[0061] In this example, the process conditions and hydrotreating effects are shown in Table 5.

[0062] Example 2

[0063] The method of this example adopts the process as Figure 1 follows, including:

[0064] (1) The heavy oil raw material is mixed with hydrogen and enters the ebullated bed hydrotreating reaction zone for hydrothermal cracking reaction. The effluent from the ebullated bed hydrotreating reaction enters the separator. The separated gas-phase stream is recycled, and the liquid-phase stream enters the fractionating tower, where gas fractions, light distillate oil, diesel oil, wax oil, and tail oil are fractionated;

[0065] (2) The light distillate oil obtained in step (1) is mixed with hydrogen and sequentially enters the first hydrocracking reaction zone and the second hydrocracking reaction zone. The first hydrocracking reaction zone is filled with the shape-selective cracking catalyst Cat-A2; the second hydrocracking reaction zone is filled with the hydrocracking catalyst Cat-B2. In step (2), the content of C7 n-paraffins in the effluent from the first hydrocracking reaction is controlled to be 2%. + ​​

[0066] (3) The reaction effluent from the second hydrocracking reaction zone in step (2) is separated into a gas-phase stream and a liquid-phase stream. The gas-phase stream is recycled, and the liquid-phase stream enters the fractionating tower, where gas fractions, light naphtha, and heavy naphtha are fractionated out.

[0067] In this example, the process conditions and the hydrotreating effect are shown in Table 5.

[0068] Example 3

[0069] The method of this example uses the following Figure 1 process, including:

[0070] (1) The heavy oil feedstock is mixed with hydrogen and enters the ebullated bed hydrotreating reaction zone for hydrothermal cracking reaction. The resulting ebullated bed hydrotreating reaction effluent enters the separator. The separated gas-phase stream is recycled, and the liquid-phase stream enters the fractionating tower, where gas fractions, light distillate oil, diesel, wax oil, and tail oil are fractionated out;

[0071] (2) The light distillate oil obtained in step (1) is mixed with hydrogen and sequentially enters the first hydrocracking reaction zone and the second hydrocracking reaction zone. The first hydrocracking reaction zone is filled with the shape-selective cracking catalyst Cat-A3; the second hydrocracking reaction zone is filled with the hydrocracking catalyst Cat-B1. In step (2), the content of C7 + n-paraffins in the effluent from the first hydrocracking reaction is controlled to be 4%.

[0072] (3) The reaction effluent from the second hydrocracking reaction zone in step (2) is separated into a gas-phase stream and a liquid-phase stream. The gas-phase stream is recycled, and the liquid-phase stream enters the fractionating tower, where gas fractions, light naphtha, and heavy naphtha are fractionated out.

[0073] In this example, the process conditions and the hydrotreating effect are shown in Table 5.

[0074] Example 4

[0075] The first hydrocracking reaction zone is filled with the same first hydrocracking catalyst Cat-A1 as in Example 1.

[0076] The second hydrocracking reaction zone is filled with the second hydrocracking catalyst Cat-B2.

[0077] The method of this example uses the following Figure 1 process, including:

[0078] (1) The heavy oil feedstock is mixed with hydrogen and enters the ebullated bed hydrotreating reaction zone for hydrothermal cracking reaction. The resulting ebullated bed hydrotreating reaction effluent enters the separator. The separated gas-phase stream is recycled, and the liquid-phase stream enters the fractionating tower, where gas fractions, light distillate oil, diesel, wax oil, and tail oil are fractionated out;

[0079] (2) The light distillate oil obtained in step (1) is mixed with hydrogen and successively enters the first hydrocracking reaction zone and the second hydrocracking reaction zone; the first hydrocracking reaction zone is filled with the shape-selective cracking catalyst Cat-A1; the second hydrocracking reaction zone is filled with the hydrocracking catalyst Cat-B2; in step (2), the content of C7 n-paraffins in the effluent of the first hydrocracking reaction is controlled + to be 1%.

[0080] (3) The effluent of the second hydrocracking reaction zone in step (2) is separated into a gas-phase stream and a liquid-phase stream by gas-liquid separation. The gas-phase stream is recycled, and the liquid-phase stream enters the fractionating tower, where gas fractions, light naphtha, and heavy naphtha are fractionated.

[0081] In this example, the process conditions and the hydrotreating effect are shown in Table 5.

[0082] Comparative Example 1

[0083] The difference from Example 1 is that the ebullated-bed light distillate oil directly enters the second hydrocracking reaction zone and reacts with the Cat-B1 catalyst.

[0084] In this example, the process conditions and the hydrotreating effect are shown in Table 5.

[0085] Comparative Example 2

[0086] The difference from Example 1 is that in step (2), the content of C7 n-alkanes in the product of the first hydrocracking reaction is controlled + to be 6%.

[0087] In this example, the process conditions and the hydrotreating effect are shown in Table 5.

[0088] Comparative Example 3

[0089] The difference from Example 3 is that the first hydrocracking reaction zone is filled with the catalyst Cat-B2.

[0090] In this example, the process conditions and the hydrotreating effect are shown in Table 5.

[0091] Comparative Example 4

[0092] The difference from Example 1 is that the mass content of bicyclic aromatic hydrocarbons in the ebullated-bed light distillate oil is 2.5%.

[0093] In this example, the process conditions and the hydrotreating effect are shown in Table 5.

[0094] Table 1 Physicochemical properties of the first hydrocracking catalyst

[0095] Catalyst Cat-A1 Cat-A2 Cat-A3 <![CDATA[Pore volume, cm 3 / g]]> 0.35 0.45 0.25 <![CDATA[Specific surface area, m 2 / g]]> 300 200 400 Content, wt%, based on the weight of the support ZSM-5 58 42 85 Aluminum oxide 42 58 15 Active metal content in the catalyst, wt% <![CDATA[MoO3]]> 10.0 15.0 5.0 NiO 3.5 2.0 5.0 <![CDATA[SiO2 / Al2O3 molar ratio of ZSM-5]]> 40 60 20

[0096] Table 2 Physicochemical properties of the second hydrocracking catalyst

[0097] Catalyst properties Cat-B1 Cat-B2 <![CDATA[Pore volume, cm 3 / g]]> 0.35 0.35 <![CDATA[Specific surface area, m 2 / g]]> 300 300 Catalyst composition and content Beta, wt% 50 - Y, wt% - 50 <![CDATA[MoO3, wt%]]> 10 10 NiO, wt% 5 5 Aluminum oxide, wt% 35 35

[0098] Table 3 Main Properties of Raw Materials

[0099] Name of feedstock Vacuum residue <![CDATA[Density (20 °C) / kg·m -3 > 1.032 Distillation range / °C IBP / 10% 464 / 558 30％ / 50％ 606 / 646 70％ / 90％ 749 / 973 95% / EBP 1025 / 1055 Sulfur content, wt% 5.61 Nitrogen content, wt% 0.38 Ni + V, mg / kg 200

[0100] Table 4 Fluidized Bed Hydroprocessing Conditions and Main Properties of Fluidized Bed Light Distillate Oil

[0101]

[0102] Continued Table 4

[0103]

[0104]

[0105] Table 5 Hydroprocessing Effect

[0106]

[0107] Continued Table 5

[0108]

[0109]

[0110] The specific embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A processing method for producing chemical raw materials from vacuum residue, the method comprising: (1) Mixing the vacuum residue raw material with hydrogen and entering a fluidized bed hydrocracking reaction zone for hydrothermal cracking reaction, and separating and fractionating to obtain fluidized bed light distillate oil; wherein, the mass content of bicyclic aromatic hydrocarbons in the fluidized bed light distillate oil is 0.1% - 1.0%; (2) In the presence of hydrogen, the light fraction of the fluidized bed obtained in step (1) enters the first hydrocracking reaction zone to selectively crack the n-alkanes in the hydrocarbon oil feedstock to obtain a first hydrocracking product; wherein, the mass content of C7 + n-alkanes in the first hydrocracking product is controlled to be 0.1% to 5.0%; (3) In the presence of hydrogen, the first hydrocracking product enters a second hydrocracking reaction zone to obtain a second hydrocracking product containing monocyclic cyclic hydrocarbons; (4) The second hydrocracking product is separated and fractionated to obtain a gas fraction, light naphtha, and heavy naphtha; The first hydrocracking reaction zone is filled with a first hydrocracking catalyst, and the second hydrocracking reaction zone is filled with a second hydrocracking catalyst; In step (2), the first hydrocracking catalyst includes an active metal component and a carrier; the carrier includes a molecular sieve having the selectivity to crack n-paraffins, and the molecular sieve is selected from one or more of ZSM-5 molecular sieve, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35, and ZSM-38 molecular sieves; the active metal component includes at least one of Group VIB metals and Group VIII metals; In step (2), for the first hydrocracking catalyst, based on the weight of the catalyst, the content of the Group VIB metal in terms of oxide is 5.0% - 15.0%, the content of the Group VIII metal in terms of oxide is 2.0% - 5.0%, and the content of the carrier is 80.0% - 93.0%; in the carrier of the first hydrocracking catalyst, based on the weight of the carrier, the content of the binder is 8% - 60%, and the content of the molecular sieve is 40% - 92%; In step (3), the second hydrocracking catalyst has the function of selectively cracking the side chains of isoparaffins or cyclic hydrocarbons and retaining monocyclic cyclic hydrocarbons; The second hydrocracking catalyst includes a cracking component, a hydrogenation component, and a binder; the cracking component includes at least one of Beta molecular sieve and Y molecular sieve; In step (3), for the second hydrocracking catalyst, based on the weight of the second hydrocracking catalyst, the content of the hydrogenation component in terms of oxide is 5wt% - 40wt%; the content of the cracking component is 20wt% - 80wt%; the content of the binder is 5wt% - 75wt%; The chemical raw materials include ethane, propane, butane, light naphtha, and heavy naphtha, wherein, the heavy naphtha is used as a reforming raw material to produce BTX, and ethane, propane, butane, and light naphtha are used as raw materials for producing low-carbon olefins.

2. The method according to claim 1, characterized in that, In step (1), the mass content of bicyclic aromatic hydrocarbons in the fluidized bed light distillate oil is 0.2% - 0.6%.

3. The method according to claim 1, wherein Step (2) The mass content of C7 n-alkanes in the first hydrocracking product + is controlled to be 1.0% - 4.0%.

4. The method according to claim 1, characterized in that, In step (3), the ratio of the mass of C6 - C8 monocyclic cyclic hydrocarbons in the second hydrocracking product to the total mass of cyclic hydrocarbons in the fluidized bed light distillate oil is 0.40 - 0.

80.

5. The method according to claim 1, characterized in that, In step (3), the ratio of the mass of C6 - C8 monocyclic cyclic hydrocarbons in the second hydrocracking product to the total mass of cyclic hydrocarbons in the fluidized bed light distillate oil is 0.48 - 0.

60.

6. The method according to claim 1, characterized in that, In step (1), the initial boiling point of the vacuum residue is 420°C to 620°C; the sulfur mass content is 2% to 10%; the nitrogen mass content is 0.2% to 1.0%; the metal content is 100 mg / kg to 500 mg / kg.

7. The method according to claim 1, characterized in that In step (1), the initial boiling point of the vacuum residue is 450°C to 550°C; the sulfur mass content is 4% to 8%; the nitrogen mass content is 0.3% to 0.5%; the metal content is 200 mg / kg to 300 mg / kg.

8. The method according to claim 1, characterized in that, The reaction conditions in the fluidized bed hydrotreating reaction zone described in step (1) are as follows: reaction pressure is 10 MPa to 25 MPa; reaction temperature is 350 °C to 500 °C; hydrogen-oil volume ratio is 100:1 to 2000:1; volumetric space velocity is 0.1 h -1 ~1.5 h -1 .

9. The method according to claim 1, characterized in that, The reaction conditions in the fluidized bed hydrotreating reaction zone described in step (1) are as follows: reaction pressure is 15 MPa to 20 MPa; reaction temperature is 400 °C to 450 °C; hydrogen-oil volume ratio is 300:1 to 1000:1; volume space velocity is 0.2 h -1 ~1.0 h -1 .

10. The method according to claim 1, characterized in that In step (1), the conversion rate of the vacuum residue raw material in the ebullated bed hydrotreating reaction zone is controlled to be 60% to 90%; the conversion rate is the sum of the mass percentages of the gas fraction, light distillate oil, diesel, and wax oil in the ebullated bed hydrotreating product relative to the fresh raw material.

11. The method according to claim 1, characterized in that, In step (1), the conversion rate of the vacuum residue raw material in the ebullated bed hydrotreating reaction zone is controlled to be 70% to 80%; the conversion rate is the sum of the mass percentages of the gas fraction, light distillate oil, diesel, and wax oil in the ebullated bed hydrotreating product relative to the fresh raw material.

12. The method according to claim 1, wherein In step (1), the initial boiling point of the ebullated bed light distillate oil is 50°C to 80°C, and the final boiling point is 190°C to 240°C; and / or, the mass content of bicyclic aromatic hydrocarbons in the ebullated bed light distillate oil is 0.2% to 0.6%.

13. The method according to claim 1, characterized in that In step (1), the initial boiling point of the ebullated bed light distillate oil is 60°C to 70°C, and the final boiling point is 200°C to 220°C.

14. The method according to claim 1, wherein In step (2), in the first hydrocracking catalyst, the molecular sieve is ZSM-5 molecular sieve; the Group VIB metals are molybdenum and / or tungsten, and the Group VIII metals are cobalt and / or nickel.

15. The method according to claim 1, wherein In step (3), for the second hydrocracking catalyst, based on the weight of the second hydrocracking catalyst, the content of the hydrogenation component in terms of oxide is 10 wt% to 20 wt%; the content of the cracking component is 3 wt% to 70 wt%; the content of the binder is 10 wt% to 50 wt%.

16. The method according to claim 1, wherein In step (2), the reaction conditions of the first hydrocracking reaction are as follows: The reaction pressure is 1.0 to 5.0 MPa; The average reaction temperature is 250 to 450°C; The hourly space velocity of the liquid is 0.1 to 15.0 h -1 ; The hydrogen-oil volume ratio is 100:1 to 2500:

1.

17. The method according to claim 1, wherein In step (2), the reaction conditions of the first hydrocracking reaction are as follows: The reaction pressure is 2.0 to 4.0 MPa; The average reaction temperature is 300 to 400°C; The hourly space velocity of the liquid is 1.0 to 5.0 h -1 ; The hydrogen-oil volume ratio is 400:1 to 2000:

1.

18. The method according to claim 1, characterized in that In step (3), the reaction conditions of the second hydrocracking reaction are as follows: The reaction pressure is 1.0 to 5.0 MPa; The average reaction temperature is 250 to 450°C; The hourly space velocity of the liquid is 0.1 to 15.0 h -1 ; The hydrogen-oil volume ratio is 100:1 to 2500:

1.

19. The method according to claim 1, wherein In step (3), the reaction conditions of the second hydrocracking reaction are as follows: The reaction pressure is 2.0 to 4.0 MPa; The average reaction temperature is 300 to 400°C; The hourly space velocity of the liquid is 1.0 to 5.0 h -1 ; The hydrogen-oil volume ratio is 400:1 to 2000:1.

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