Crude oil processing method and system capable of maximally producing chemicals and marine fuel

Abstract

The invention relates to a crude oil processing method for maximally producing chemicals and simultaneously producing marine fuels, which comprises the following steps: carrying out pyrolysis gasoline hydrotreatment and pyrolysis gasoline extraction treatment on hydrocracking gasoline, second pyrolysis gasoline and third pyrolysis gasoline to obtain C6-C8 aromatic hydrocarbons; performing ethane cracking treatment on the first cracking dry gas, the second cracking dry gas and the third cracking dry gas to obtain ethylene; carrying out gas separation on the first cracked liquefied gas, the second cracked liquefied gas and the third cracked liquefied gas to obtain a first stream of propylene, propane and C4 mixed hydrocarbon; carrying out propane dehydrogenation on the propane to obtain a second strand of propylene; and the pyrolysis slurry oil and part of residual oil hydrogenated heavy oil are blended to produce the low-sulfur ship fuel at low cost. According to the present invention, the catalytic cracking treatment of each fraction section of the crude oil is achieved, the resource utilization efficiency is improved, the maximum production of the low-carbon olefin and the C6-C8 aromatic hydrocarbon product is easily achieved while the ship combustion production is considered, and the yield of the low-carbon olefin and the C6-C8 aromatic hydrocarbon product is improved.

Description

Technical Field

[0001] The present invention relates to the field of petrochemical industry, and in particular to a crude oil processing method and system for maximizing the production of chemical products and concurrently producing marine fuel. Background Art

[0002] Currently, the production capacity of refined oil products is in a state of oversupply. With the continuous increase in refining capacity and the accelerated impact of new energy, the trend of oversupply of refined oil products will continue to intensify in the future.

[0003] In the refined oil market, diesel consumption has reached its peak, and gasoline demand is expected to reach its peak as well. At the same time, basic organic chemical raw materials such as aromatics and ethylene are in serious shortage. At present, the proportion of chemical demand in oil consumption will increase year by year. The situation of surplus refined oil and shortage of organic chemical raw materials has made it a general trend for oil refining enterprises to transform and upgrade from "fuel type" to "chemical type".

[0004] Marine fuel oil is fuel oil used for marine internal combustion engines. According to my country's national standard GB17411-2015, marine fuel oil is divided into Group D (distillate fuel oil, marine light oil) and Group R (residual fuel oil, marine heavy oil). Residual marine fuel oil is usually called heavy marine fuel oil, which is mainly used for low-speed diesel engines as ship propulsion power. In order to control ship emission pollution, according to the International Convention for the Prevention of Pollution from Ships (IMO), the sulfur content of global low-sulfur heavy marine fuel oil (hereinafter referred to as low-sulfur marine fuel) shall not exceed 0.5%. The consumption of low-sulfur marine fuel has been growing steadily. In the process of chemical transformation, hydrocarbons that are not easy to crack are used as marine fuel oil. Making full use of refinery resources for the production of low-sulfur marine fuel can also help release refining capacity.

[0005] In the existing refinery crude oil processing process, traditional refineries mainly produce fuel oils such as gasoline, kerosene and diesel, with a small amount of propylene and aromatics as by-products. The yield of chemical products is low, and the crude oil conversion rate is not high, which cannot meet the growing demand for organic chemical raw materials. The use of existing refining and chemical technologies to design refineries for full chemical product production, maximize the yield of chemical products, and produce marine fuel at the same time can break the traditional refinery process and provide guidance for the chemical transformation of existing refineries.

[0006] For example, patent documents CN113817500A, CN113817502A, CN113817505A, etc., first carry out targeted modification of crude oil, and then carry out selective hydrogenation, adsorption separation, aromatics production increase, olefins production increase and other processes.

[0007] However, among the products obtained from the existing refinery crude oil processing methods, the proportion of non-chemical products other than ethylene, propylene and C6-C8 aromatics is still relatively high. Summary of the invention

[0008] The purpose of the present invention is to further increase the proportion of ethylene, propylene and C6-C8 aromatics in the products obtained by the crude oil processing method, and take into account the production of marine fuel, so as to greatly improve the crude oil conversion efficiency.

[0009] In order to achieve the above-mentioned object, the first aspect of the present invention provides a crude oil processing method for maximizing the production of chemical products and concurrently producing marine fuel, the method comprising the following steps:

[0010] S1, separating crude oil into naphtha fraction, straight-run diesel fraction and atmospheric residue fraction;

[0011] S2, hydrogenating the atmospheric residue fraction to obtain residue hydrogenated diesel and residue hydrogenated heavy oil; separating a first stream of residue hydrogenated heavy oil and a second stream of residue hydrogenated heavy oil from the residue hydrogenated heavy oil, subjecting the first stream of residue hydrogenated heavy oil to a first catalytic cracking to obtain a first cracked dry gas, a first cracked liquefied gas, a first cracked gasoline, a first cracked diesel and a cracked oil slurry; mixing the second stream of residue hydrogenated heavy oil with the cracked oil slurry to obtain a marine fuel;

[0012] S3, hydrofining the straight-run diesel fraction and the residual oil hydrogenated diesel to obtain refined diesel; performing a second catalytic cracking on the refined diesel to obtain a second cracked dry gas, a second cracked liquefied gas, a second cracked gasoline and a second cracked diesel;

[0013] S4, subjecting the naphtha fraction and the first pyrolysis gasoline to a third catalytic cracking to obtain a third pyrolysis dry gas, a third pyrolysis liquefied gas and a third pyrolysis gasoline;

[0014] S5, hydrocracking the first pyrolysis diesel and the second pyrolysis diesel to obtain hydrocracking gasoline and hydrocracking diesel; returning the hydrocracking diesel to the first catalytic cracking of step S2; subjecting the hydrocracking gasoline, the second pyrolysis gasoline and the third pyrolysis gasoline 131 to pyrolysis gasoline hydrogenation treatment and pyrolysis gasoline extraction treatment to obtain C6-C8 aromatics, raffinate oil and heavy aromatics above C9; returning the raffinate oil to the third catalytic cracking of step S4; returning the heavy aromatics to the hydrocracking of step S5;

[0015] S6, subjecting the first cracked dry gas, the second cracked dry gas and the third cracked dry gas to ethane cracking treatment to obtain ethylene;

[0016] S7, the first cracked liquefied gas, the second cracked liquefied gas and the third cracked liquefied gas are subjected to gas separation to obtain a first stream of propylene, propane and C4 mixed hydrocarbons; the propane is subjected to propane dehydrogenation to obtain a second stream of propylene, and the C4 mixed hydrocarbons are subjected to superposition reaction to obtain superposition oil and remaining C4 hydrocarbons; the superposition oil is returned to the third catalytic cracking of step S4, the remaining C4 hydrocarbons are subjected to light hydrocarbon conversion to produce propane to obtain propane conversion gas, and the propane conversion gas is returned to the gas separation of step S7.

[0017] Optionally, in step S7, the gas fraction further produces at least one of 1-butene, 2-butene and butadiene.

[0018] Optionally, in step S1, the cutting point between the naphtha fraction and the straight-run diesel fraction is any temperature between 175-205°C, and the cutting point between the straight-run diesel fraction and the atmospheric residue fraction is any temperature between 335-370°C.

[0019] Optionally, in step S2, the reaction conditions of the hydrotreatment include: reaction temperature of 300-460°C, reaction pressure of 6-25MPa, hydrogen-oil volume ratio of (100-1500):1; the separation cut point of hydrogenated diesel and residual oil hydrogenated heavy oil is any temperature between 335-370°C.

[0020] Optionally, the first catalytic cracking conditions include: a reaction temperature of 400-650°C, a reaction pressure of 0.05-1MPa, and a catalyst-oil weight ratio of (5-50):1; the separation cut point of the first cracked dry gas and the first cracked liquefied gas is any temperature between 14-16°C, the separation cut point of the first cracked liquefied gas and the first cracked gasoline is any temperature between 38-62°C, and the separation cut point of the first cracked gasoline and the first cracked diesel is any temperature between 175-205°C; the weight ratio of the first residue oil hydrogenated heavy oil to the second residue oil hydrogenated heavy oil is (1-15):1.

[0021] Optionally, in step S3, the reaction conditions of the hydrotreating include: a reaction temperature of 200-400° C., a reaction pressure of 2-16 MPa, and a hydrogen-to-oil volume ratio of (400-1000):1.

[0022] Optionally, the second catalytic cracking conditions include: a reaction temperature of 500-750°C, a reaction pressure of 0.05-1MPa, a catalyst-oil weight ratio of (5-100):1, preferably (10-50):1; the separation cut point of the second cracked dry gas and the second cracked liquefied gas is any temperature between 14-16°C, the separation cut point of the second cracked liquefied gas and the second cracked gasoline is any temperature between 38-62°C, and the separation cut point of the second cracked gasoline and the second cracked diesel is any temperature between 175-205°C.

[0023] Optionally, in step S4, the third catalytic cracking conditions include: a reaction temperature of 500-750°C, a reaction pressure of 0.05-1MPa, a catalyst-oil weight ratio of (5-100):1, preferably (10-50):1; the separation cut point of the third cracking dry gas and the third cracking liquefied gas is any temperature between 14-16°C, and the separation cut point of the third cracking liquefied gas and the third cracking gasoline is any temperature between 38-62°C.

[0024] Optionally, in step S5, the reaction conditions of the hydrocracking treatment include: a reaction temperature of 260 to 500°C, a hydrogen partial pressure of 3 to 10 MPa, and a volume space velocity of 0.5 to 6 h -1 The separation cutting point of hydrocracking gasoline and hydrocracking diesel is any temperature between 175-205℃.

[0025] Optionally, the reaction conditions for the pyrolysis gasoline hydrotreatment include: a hydrogenation unit reaction temperature of 300-400°C, a reaction pressure of 4-16MPa, and a hydrogen-to-oil volume ratio of (300-1000):1; the conditions for the pyrolysis gasoline extraction include: a temperature of 20-100°C, a pressure of 0.05-0.5MPa, and a weight ratio of the extraction solvent to the feedstock oil of (0.5-2.5):1.

[0026] Optionally, in step S6, the reaction conditions of the ethane cracking treatment include: a reaction pressure of 0.10 to 0.25 MPa, a reaction temperature of 810 to 870° C., and a residence time of 0.25 to 0.4 s.

[0027] Optionally, in step S7, the reaction conditions of the propane dehydrogenation treatment include: reaction temperature 400-700°C, reaction pressure 0.05-1 MPa, reaction time 40-60 h, propane mass space velocity 2-9 h -1 .

[0028] Optionally, the reaction conditions of the superposition reaction include: reaction temperature of 40-350°C, preferably 200-300°C, reaction pressure of 0.5-10 MPa, mass space velocity of 0.2-20 h -1; The separation cutting point of the superimposed oil and the remaining C4 hydrocarbons is any temperature between 30-65°C.

[0029] Optionally, the reaction conditions for converting light hydrocarbons to propane include: reaction temperature of 250-550°C, reaction pressure of 0.1-2 MPa, mass space velocity of 0.1-3 h -1 .

[0030] The second aspect of the present invention provides a crude oil processing system for maximizing the production of chemical products and concurrently producing marine fuel, the system comprising: an atmospheric pressure unit, a third catalytic cracking unit, a diesel hydrorefining unit, a residual oil hydrogenation unit, an ethane cracking unit, a gas separation unit, a second catalytic cracking unit, a first catalytic cracking unit, a pyrolysis gasoline hydrogenation unit, a pyrolysis gasoline extraction unit, a catalytic diesel hydrocracking unit to produce aromatics, a propane dehydrogenation unit, a superposition unit and a light hydrocarbon conversion unit to produce propane.

[0031] Optionally, the naphtha fraction outlet of the atmospheric pressure device is connected to the third catalytic cracking inlet of the third catalytic cracking device; the third cracking dry gas outlet of the third catalytic cracking device is connected to the cracking dry gas inlet of the ethane cracking device.

[0032] Optionally, the straight-run diesel fraction outlet of the atmospheric pressure unit is connected to the first diesel hydrorefining inlet of the diesel hydrorefining unit, and the refined diesel outlet of the diesel hydrorefining unit is connected to the refined diesel inlet of the second catalytic cracking unit.

[0033] Optionally, the atmospheric residue fraction outlet of the atmospheric pressure unit is connected to the atmospheric residue fraction inlet of the residue hydrogenation unit, the residue hydrogenated diesel outlet of the residue hydrogenation unit is connected to the second diesel hydrogenation refining inlet of the diesel hydrotreating unit, the first residue hydrogenated heavy oil outlet of the residue hydrogenation unit is connected to the residue hydrogenated heavy oil inlet of the first catalytic cracking unit, and the second residue hydrogenated heavy oil outlet of the residue hydrogenation unit is connected to the cracked oil slurry outlet of the first catalytic cracking unit; the first cracked dry gas outlet of the first catalytic cracking unit and the second cracked dry gas outlet of the second catalytic cracking unit are respectively connected to the connecting pipelines between the third cracked dry gas outlet of the third catalytic cracking unit and the cracked dry gas inlet of the ethane cracking unit.

[0034] Optionally, the second cracked liquefied gas outlet of the second catalytic cracking unit is connected to the first cracked liquefied gas inlet of the gas separation unit, and the third cracked liquefied gas outlet of the third catalytic cracking unit and the first cracked liquefied gas outlet of the first catalytic cracking unit are respectively connected to the connecting pipeline between the second cracked liquefied gas outlet and the first cracked liquefied gas inlet; the third cracked gasoline outlet of the third catalytic cracking unit is connected to the cracked gasoline inlet of the cracked gasoline hydrogenation unit, the second cracked gasoline outlet of the second catalytic cracking unit is connected to the connecting pipeline between the third cracked gasoline outlet and the first cracked gasoline inlet, and the first cracked gasoline outlet of the first catalytic cracking unit is connected to the third catalytic cracking inlet.

[0035] Optionally, the first cracking diesel outlet of the first catalytic cracking unit is connected to the first cracking diesel inlet of the catalytic diesel hydrocracking unit to produce aromatics, and the second cracking diesel outlet of the second catalytic cracking unit is connected to the connecting pipeline between the first cracking diesel outlet and the first cracking diesel inlet; the hydrocracking gasoline outlet of the catalytic diesel hydrocracking unit to produce aromatics is connected to the cracking gasoline inlet of the cracking gasoline hydrogenation unit; the hydrocracking diesel outlet of the catalytic diesel hydrocracking unit to produce aromatics is connected to the first catalytic cracking inlet of the first catalytic cracking unit.

[0036] Optionally, the propane outlet of the gas separation device is communicated with the propane inlet of the propane dehydrogenation device, and the first propylene outlet of the gas separation device is communicated with the second propylene outlet of the propane dehydrogenation device.

[0037] Optionally, the product outlet of the pyrolysis gasoline hydrogenation unit is connected to the feedstock inlet of the pyrolysis gasoline extraction unit.

[0038] Optionally, the raffinate outlet of the pyrolysis gasoline extraction unit is connected to the connecting pipeline between the naphtha fraction outlet and the third catalytic cracking inlet; the heavy aromatics outlet of the pyrolysis gasoline extraction unit is connected to the heavy aromatics inlet of the catalytic diesel hydrocracking aromatics unit.

[0039] Optionally, the C4 mixed hydrocarbon outlet of the gas separation device is connected to the C4 mixed hydrocarbon inlet of the superposition device, and the superposition oil outlet of the superposition device is connected to the connecting pipeline between the naphtha fraction outlet and the third catalytic cracking inlet; the remaining C4 hydrocarbon outlet of the superposition device is connected to the remaining C4 hydrocarbon inlet of the light hydrocarbon conversion to propane device, and the propane conversion gas outlet of the light hydrocarbon conversion to propane device is connected to the second cracked liquefied gas inlet of the gas separation device.

[0040] Through the above technical scheme, the present invention provides a crude oil processing method and system for producing all chemical products. The present invention introduces crude oil into a normal pressure device for normal pressure separation, and naphtha, diesel and atmospheric residue fractions can be obtained, which is conducive to catalytic cracking reactions of each separated fraction segment; the present invention catalytically cracks naphtha, diesel and atmospheric residue fractions respectively, which is conducive to improving the yield of ethylene, propylene and C6-C8 aromatic products; the present invention sends the cracked dry gas to the ethane cracking device to improve the ethylene yield; the present invention performs propane dehydrogenation reaction on the gas fraction propane to improve the propylene yield; the present invention can also perform catalytic diesel hydrocracking on the cracked diesel in the cracking product, and return it as hydrocracking gasoline to the cracked gasoline hydrogenation device and the extraction device for extraction and separation, thereby improving the aromatic yield. The cracked oil slurry and part of the residue oil hydrogenation heavy oil are blended to produce low-sulfur marine fuel at low cost. The present invention can also return the gas fraction liquefied gas to the light oil catalytic cracking device and the gas fraction device after superposition and light hydrocarbon conversion to propane production device, which is conducive to improving the yield of chemical products. The present invention realizes catalytic cracking treatment of each fraction of crude oil, improves resource utilization efficiency, and is beneficial to maximizing the production of low-carbon olefins and C6-C8 aromatic products while taking into account the production of marine fuel, thereby realizing a production plan of producing only chemical products without producing any oil products.

[0041] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention, but do not constitute a limitation of the present invention. In the accompanying drawings:

[0043] Figure 1 The present invention provides a schematic flow diagram of a crude oil processing system for maximizing the production of chemical products and concurrently producing marine fuel.

[0044] Description of Reference Numerals

[0045] 9-normal pressure unit, 10-third catalytic cracking unit, 11-diesel hydrorefining unit, 12-residue oil hydrogenation unit, 13-ethane cracking unit, 14-gas separation unit, 15-second catalytic cracking unit, 16-first catalytic cracking unit, 17-pyrolysis gasoline hydrogenation unit, 18-catalytic diesel hydrocracking aromatics unit, 19-propane dehydrogenation unit, 20-superposition unit, 21-light hydrocarbon conversion propane unit, 22-pyrolysis gasoline extraction unit;

[0046] 125-crude oil, 126-naphtha fraction, 127-straight-run diesel fraction, 128-atmospheric residue fraction, 129-third cracking dry gas, 130-third cracking liquefied gas, 131-third cracking gasoline, 132-refined diesel, 133-residue oil hydrogenated diesel, 134-residue oil hydrogenated heavy oil, 135-propane, 136-C4 liquefied gas, 137-second cracking dry gas, 138-second cracking liquefied gas, 139-second cracking gasoline, 140-second cracking Diesel, 141-first cracking dry gas, 142-first cracking liquefied gas, 143-first cracking gasoline, 144-first cracking diesel, 145-raffinate oil, 146-heavy aromatics, 147-hydrogenated cracking gasoline, 148-hydrogenated cracking diesel, 149-ethylene, 150-propylene, 151-C6-C8 aromatics, 152-cracking slurry, 153-low-sulfur heavy marine fuel oil, 154-composite oil, 155-residual C4 hydrocarbons, 156-propane conversion gas. DETAILED DESCRIPTION

[0047] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0048] In the present invention, unless otherwise stated, the words "first", "second", etc. are used only to distinguish different components and do not have actual meanings such as the front-to-back connection order. In the present invention, the directional words used, such as "upper", "lower", "left", and "right", refer to the upper and lower, left, and right of the device in normal use, and "inside" and "outside" refer to the outline of the device.

[0049] The first aspect of the present invention provides a crude oil processing method for maximizing the production of chemical products and concurrently producing marine fuel, the method comprising the following steps:

[0050] S1, separating the crude oil 125 into a naphtha fraction 126, a straight-run diesel fraction 127 and an atmospheric residue fraction 128;

[0051] S2, hydrogenating the atmospheric residue fraction 128 to obtain residue hydrogenated diesel 133 and residue hydrogenated heavy oil 134; separating a first stream of residue hydrogenated heavy oil and a second stream of residue hydrogenated heavy oil from the residue hydrogenated heavy oil 134, performing a first catalytic cracking on the first stream of residue hydrogenated heavy oil to obtain a first cracked dry gas 141, a first cracked liquefied gas 142, a first cracked gasoline 143, a first cracked diesel 144 and a cracked oil slurry 152; mixing the second stream of residue hydrogenated heavy oil with the cracked oil slurry 152 to obtain a marine fuel 153;

[0052] S3, hydrofining the straight-run diesel fraction 127 and the residual oil hydrogenated diesel 133 to obtain refined diesel 132; performing a second catalytic cracking on the refined diesel 132 to obtain a second cracking dry gas 137, a second cracking liquefied gas 138, a second cracking gasoline 139 and a second cracking diesel 140;

[0053] S4, performing a third catalytic cracking on the naphtha fraction 126 and the first pyrolysis gasoline 143 to obtain a third pyrolysis dry gas 129, a third pyrolysis liquefied gas 130 and a third pyrolysis gasoline 131;

[0054] S5, hydrocracking the first pyrolysis diesel 144 and the second pyrolysis diesel 140 to obtain hydrocracking gasoline 147 and hydrocracking diesel 148; returning the hydrocracking diesel 148 to the first catalytic cracking of step S2; subjecting the hydrocracking gasoline 147, the second pyrolysis gasoline 139 and the third pyrolysis gasoline 131 to pyrolysis gasoline hydrogenation treatment and pyrolysis gasoline extraction treatment to obtain C6-C8 aromatics 151, raffinate 145 and heavy aromatics 146; returning the raffinate 145 to the third catalytic cracking of step S4; returning the heavy aromatics 146 to the hydrocracking of step S5;

[0055] S6, performing ethane cracking treatment on the first cracked dry gas 141, the second cracked dry gas 137 and the third cracked dry gas 129 to obtain ethylene 149;

[0056] S7, gas separation is performed on the first cracked liquefied gas 142, the second cracked liquefied gas 138 and the third cracked liquefied gas 130 to obtain a first stream of propylene 150, propane 135 and C4 mixed hydrocarbons 136; the propane 135 is subjected to propane dehydrogenation to obtain a second stream of ethylene 149 and a second stream of propylene 150, and the C4 mixed hydrocarbons 136 are subjected to superposition reaction to obtain superposition oil 154 and remaining C4 hydrocarbons 155; the superposition oil 154 is returned to the third catalytic cracking of step S4, and the remaining C4 hydrocarbons 155 are subjected to light hydrocarbon conversion to produce propane to obtain propane conversion gas 156, and the propane conversion gas 156 is returned to the gas separation of step S7.

[0057] In the present invention, crude oil is introduced into a normal pressure device for normal pressure separation, and naphtha, straight-run diesel and atmospheric residue fractions can be obtained, which is conducive to catalytic cracking reactions of the separated fractions; the present invention catalytically cracks naphtha, straight-run diesel and atmospheric residue fractions respectively, which is conducive to improving the yield of ethylene, propylene and C6-C8 aromatic products; the present invention sends the cracked dry gas to the ethane cracking device to improve the ethylene yield; the propane in the gas fraction is subjected to propane dehydrogenation reaction to improve the propylene yield; the present invention can also catalytically hydrogenate the cracked diesel in the cracking product, and then return it to the cracked gasoline hydrogenation device and the extraction device as hydrogenated cracking gasoline for extraction and separation, thereby improving the yield of aromatics. The cracked oil slurry and part of the residual oil hydrogenated heavy oil are blended to produce low-sulfur marine fuel at low cost. The present invention can also return the gas fraction liquefied gas to the light oil catalytic cracking device and the gas fraction device after superposition and light hydrocarbon conversion to propane production device, which is conducive to improving the yield of chemical products. At the same time, the raffinate is sent back to the third catalytic cracking unit to further increase the yield of olefins; and the heavy aromatics are sent back to the catalytic diesel hydrocracking aromatics unit to further increase the yield of C6-C8 aromatics.

[0058] The present invention realizes catalytic cracking treatment of each fraction of crude oil, improves resource utilization efficiency, and is beneficial to maximizing the production of low-carbon olefins and C6-C8 aromatic products while taking into account the production of marine fuel, thereby realizing a production plan of producing only chemical products without producing any oil products.

[0059] According to the present invention, optionally, in step S7, the gas fraction further produces at least one of 1-butene, 2-butene and butadiene.

[0060] According to the present invention, optionally, in step S1, the cutting point between the naphtha fraction 126 and the straight-run diesel fraction 127 is any temperature between 175-205°C, and the cutting point between the straight-run diesel fraction 127 and the atmospheric residue fraction 128 is any temperature between 335-370°C.

[0061] According to the present invention, optionally, in step S2, the reaction conditions of the hydrotreatment include: a reaction temperature of 300-460°C, a reaction pressure of 6-25MPa, a hydrogen-to-oil volume ratio of (100-1500):1; the separation cut point of the hydrogenated diesel 133 and the residue hydrogenated heavy oil 134 is any temperature between 335-370°C; and the weight ratio between the first residue hydrogenated heavy oil and the second residue hydrogenated heavy oil is (1-15):1.

[0062] According to the present invention, optionally, the first catalytic cracking conditions include: a reaction temperature of 400-650°C, a reaction pressure of 0.05-1MPa, and a catalyst-oil weight ratio of (5-50):1; the separation cut point of the first cracked dry gas 141 and the first cracked liquefied gas 142 is any temperature between 14-16°C, the separation cut point of the first cracked liquefied gas 142 and the first cracked gasoline 143 is any temperature between 38-62°C, and the separation cut point of the first cracked gasoline 143 and the first cracked diesel 144 is any temperature between 175-205°C.

[0063] According to the present invention, optionally, in step S3, the reaction conditions of the hydrotreating include: a reaction temperature of 200-400°C, a reaction pressure of 2-16MPa, and a hydrogen-to-oil volume ratio of (400-1000):1.

[0064] According to the present invention, optionally, the second catalytic cracking conditions include: a reaction temperature of 500-750°C, a reaction pressure of 0.05-1MPa, a catalyst-oil weight ratio of (5-100):1, preferably (10-50):1; the separation cut point of the second cracked dry gas 137 and the second cracked liquefied gas 138 is any temperature between 14-16°C, the separation cut point of the second cracked liquefied gas 138 and the second cracked gasoline 139 is any temperature between 38-62°C, and the separation cut point of the second cracked gasoline 139 and the second cracked diesel 140 is any temperature between 175-205°C.

[0065] According to the present invention, optionally, in step S4, the third catalytic cracking conditions include: a reaction temperature of 500-750°C, a reaction pressure of 0.05-1MPa, a catalyst-oil weight ratio of (5-100):1, preferably (10-50):1; the separation cutting point of the third cracking dry gas 129 and the third cracking liquefied gas 130 is any temperature between 14-16°C, and the separation cutting point of the third cracking liquefied gas 130 and the third cracking gasoline 131 is any temperature between 38-62°C.

[0066] According to the present invention, optionally, in step S5, the reaction conditions of the hydrocracking treatment include: a reaction temperature of 260 to 500°C, a hydrogen partial pressure of 3 to 10 MPa, and a volume space velocity of 0.5 to 6 h -1 The separation cutting point of the hydrocracked gasoline 147 and the hydrocracked diesel 148 is any temperature between 175-205°C.

[0067] According to the present invention, optionally, the reaction conditions of the pyrolysis gasoline hydrotreatment include: the reaction temperature of the hydrogenation unit is 300-400°C, the reaction pressure is 4-16MPa, and the hydrogen-oil volume ratio is (300-1000): 1, and the conditions of the pyrolysis gasoline extraction include: the temperature is 20-100°C, the pressure is 0.05-0.5MPa, and the weight ratio of the extraction solvent to the raw oil is (0.5-2.5): 1. The heavy aromatics are heavy aromatics above C9.

[0068] According to the present invention, optionally, in step S6, the reaction conditions of the ethane cracking treatment include: a reaction pressure of 0.10 to 0.25 MPa, a reaction temperature of 810 to 870° C., and a residence time of 0.25 to 0.4 s.

[0069] According to the present invention, optionally, in step S7, the reaction conditions of the propane dehydrogenation treatment include: reaction temperature 400-700°C, reaction pressure 0.05-1MPa, reaction time 40-60h, propane mass space velocity 2-9h -1 .

[0070] According to the present invention, optionally, the reaction conditions of the superposition reaction include: a reaction temperature of 40 to 350°C, a reaction pressure of 0.5 to 10 MPa, and a mass space velocity of 0.2 to 20 h -1 The separation cutting point of the superimposed oil 152 and the remaining C4 hydrocarbons 153 is any temperature between 30-65°C; the reaction conditions for the conversion of light hydrocarbons to propane are: reaction temperature of 250-550°C, reaction pressure of 0.1-2MPa, mass space velocity of 0.1-3h -1 .

[0071] The second aspect of the present invention provides a crude oil processing system for maximizing the production of chemical products and producing marine fuel, the system comprising: an atmospheric pressure device 9, a third catalytic cracking device 10, a diesel hydrofining device 11, a residual oil hydrogenation device 12, an ethane cracking device 13, a gas separation device 14, a second catalytic cracking device 15, a first catalytic cracking device 16, a cracking gasoline hydrogenation device 17, a cracking gasoline extraction device 22, a catalytic diesel hydrocracking aromatics device 18, a propane dehydrogenation device 19, a superposition device 20 and a light hydrocarbon conversion propane device 21. Each device used in the present invention is a conventional device used in the art. In the processing process of the present invention, the third catalytic cracking device and the second catalytic cracking device have insufficient heat supply due to the light raw materials, which is provided by the cracking oil slurry and char produced as by-products of the first catalytic cracking device.

[0072] According to the present invention, optionally, the naphtha fraction outlet of the atmospheric pressure device 9 is connected to the third catalytic cracking inlet of the third catalytic cracking device 10; the third cracked dry gas outlet of the third catalytic cracking device 10 is connected to the cracked dry gas inlet of the ethane cracking device 13.

[0073] According to the present invention, optionally, the straight-run diesel fraction outlet of the atmospheric pressure device 9 is connected to the first diesel hydrotreating inlet of the diesel hydrotreating device 11, and the refined diesel outlet of the diesel hydrotreating device 11 is connected to the refined diesel inlet of the second catalytic cracking device 15.

[0074] According to the present invention, optionally, the atmospheric residue fraction outlet of the atmospheric pressure device 9 is connected to the atmospheric residue fraction inlet of the residue hydrogenation device 12, the residue hydrogenated diesel outlet of the residue hydrogenation device 12 is connected to the second diesel hydrogenation refining inlet of the diesel hydrotreating device 11, the first residue hydrogenated heavy oil outlet of the residue hydrogenation device 12 is connected to the residue hydrogenated heavy oil inlet of the first catalytic cracking device 16, and the second residue hydrogenated heavy oil outlet of the residue hydrogenation device 16 is connected to the cracked oil slurry outlet of the first catalytic cracking device 16; the first cracked dry gas outlet of the first catalytic cracking device 16 and the second cracked dry gas outlet of the second catalytic cracking device 15 are respectively connected to the connecting pipelines between the third cracked dry gas outlet of the third catalytic cracking device 10 and the cracked dry gas inlet of the ethane cracking device 13.

[0075] According to the present invention, optionally, the second cracked liquefied gas outlet of the second catalytic cracking unit 15 is connected to the first cracked liquefied gas inlet of the gas separation unit 14, and the third cracked liquefied gas outlet of the third catalytic cracking unit 10 and the first cracked liquefied gas outlet of the first catalytic cracking unit 16 are respectively connected to the connecting pipeline between the second cracked liquefied gas outlet and the first cracked liquefied gas inlet; the third cracked gasoline outlet of the third catalytic cracking unit 10 is connected to the cracked gasoline inlet of the cracked gasoline hydrogenation unit 17, and the second cracked gasoline outlet of the second catalytic cracking unit 15 is connected to the connecting pipeline between the third cracked gasoline outlet and the first cracked gasoline inlet.

[0076] According to the present invention, optionally, the first cracking gasoline outlet of the first catalytic cracking unit 16 is connected to the third catalytic cracking inlet; the first cracking diesel outlet of the first catalytic cracking unit 16 is connected to the first cracking diesel inlet of the catalytic diesel hydrocracking unit 18 to produce aromatics, and the second cracking diesel outlet of the second catalytic cracking unit 15 is connected to the connecting pipeline between the first cracking diesel outlet and the first cracking diesel inlet; the hydrocracking gasoline outlet of the catalytic diesel hydrocracking unit 18 to produce aromatics is connected to the cracking gasoline inlet of the cracking gasoline hydrogenation unit 17; the hydrocracking diesel outlet of the catalytic diesel hydrocracking unit 18 to produce aromatics is connected to the first catalytic cracking inlet of the first catalytic cracking unit 16.

[0077] According to the present invention, optionally, the propane outlet of the gas separation device 14 is connected to the propane inlet of the propane dehydrogenation device 19 , and the first propylene outlet of the gas separation device 14 is connected to the second propylene outlet of the propane dehydrogenation device 19 .

[0078] According to the present invention, optionally, the product outlet of the pyrolysis gasoline hydrogenation device 17 is connected to the feedstock inlet of the pyrolysis gasoline extraction device 22 .

[0079] According to the present invention, optionally, the raffinate outlet of the pyrolysis gasoline extraction device 22 is connected to the connecting pipeline between the naphtha fraction outlet and the third catalytic cracking inlet; the heavy aromatics outlet of the pyrolysis gasoline extraction device 22 is connected to the heavy aromatics inlet of the catalytic diesel hydrocracking aromatics production device 18.

[0080] According to the present invention, optionally, the C4 mixed hydrocarbon outlet of the gas separation device 14 is connected to the C4 mixed hydrocarbon inlet of the superposition device 20, and the superposition oil outlet of the superposition device 20 is connected to the connecting pipeline between the naphtha fraction outlet and the third catalytic cracking inlet; the remaining C4 hydrocarbon outlet of the superposition device 20 is connected to the remaining C4 hydrocarbon inlet of the light hydrocarbon conversion to propane device 21, and the propane conversion gas outlet of the light hydrocarbon conversion to propane device 21 is connected to the second cracking liquefied gas inlet of the gas separation device 14.

[0081] The present invention is further illustrated by the following examples, but the present invention is not limited thereto.

[0082] The crude oil used in Example 1 is Saudi Arabian medium crude oil, and the density of crude oil is 869.2 kg / m 3 , sulfur mass fraction 2.6%, acid value 0.19mgKOH / g.

[0083] Example 1

[0084] according to Figure 1The crude oil processing system shown in the figure, which maximizes the production of chemical products and also produces marine fuel, produces light olefins and C6-C8 aromatics. The specific process is as follows:

[0085] S1, separating the crude oil 125 into a naphtha fraction 126, a straight-run diesel fraction 127 and an atmospheric residue fraction 128;

[0086] S2, hydrogenating the atmospheric residue fraction 128 to obtain residue hydrogenated diesel 133 and residue hydrogenated heavy oil 134; separating a first stream of residue hydrogenated heavy oil and a second stream of residue hydrogenated heavy oil from the residue hydrogenated heavy oil 134, subjecting the first stream of residue hydrogenated heavy oil to a first catalytic cracking to obtain a first cracking dry gas 141, a first cracking liquefied gas 142, a first cracking gasoline 143, a first cracking diesel 144 and a cracking oil slurry 152; mixing the second stream of residue hydrogenated heavy oil with the cracking oil slurry 152 to obtain a marine fuel 153; wherein the reaction temperature of the hydrogenation treatment is 400°C, the pressure is 16MPa, and the hydrogen-to-oil volume ratio is 800:1; the reaction temperature of the first catalytic cracking is 550°C, the reaction pressure is 0.35MPa, and the catalyst-to-oil weight ratio is 30:1; the weight ratio between the first stream of residue hydrogenated heavy oil and the second stream of residue hydrogenated heavy oil is 13:1;

[0087] S3, hydrofining the straight-run diesel fraction 127 and the residual oil hydrogenated diesel 133 to obtain refined diesel 132; performing a second catalytic cracking on the refined diesel 132 to obtain a second cracking dry gas 137, a second cracking liquefied gas 138, a second cracking gasoline 139 and a second cracking diesel 140; wherein the reaction temperature of the hydrofining is 300° C., the reaction pressure is 12 MPa, and the hydrogen-oil volume ratio is 700:1; the second catalytic cracking reaction temperature is 650° C., the reaction pressure is 0.1 MPa, and the catalyst-oil weight ratio is 11:1;

[0088] S4, subjecting the naphtha fraction 126 and the first pyrolysis gasoline 143 to a third catalytic cracking to obtain a third pyrolysis dry gas 129, a third pyrolysis liquefied gas 130 and a third pyrolysis gasoline 131; wherein the reaction temperature is 670° C., the reaction pressure is 0.1 MPa, and the catalyst-oil weight ratio is 12:1;

[0089] S5, the first pyrolysis diesel 144 and the second pyrolysis diesel 140 are subjected to hydrocracking to obtain hydrocracking gasoline 147 and hydrocracking diesel 148; the hydrocracking diesel 148 is returned to the first catalytic cracking of step S2; the hydrocracking gasoline 147, the second pyrolysis gasoline 139 and the third pyrolysis gasoline 131 are subjected to pyrolysis gasoline hydrogenation treatment and pyrolysis gasoline extraction treatment to obtain C6-C8 aromatics 151, raffinate 145 and heavy aromatics above C9 146; the raffinate 145 is returned to the third catalytic cracking of step S4; the heavy aromatics 146 are returned to the hydrocracking of step S5; wherein the reaction temperature of the hydrocracking is 360°C, the hydrogen partial pressure is 6MPa, and the volume space velocity is 2h -1 The reaction temperature of the hydrogenation unit of the pyrolysis gasoline hydrotreatment is 350°C, the reaction pressure is 10MPa, the hydrogen-to-oil volume ratio is 600:1, the temperature of the pyrolysis gasoline extraction is 40°C, the pressure is 0.1MPa, and the weight ratio of the extraction solvent to the raw oil is 1.5:1;

[0090] S6, subjecting the first cracked dry gas 141, the second cracked dry gas 137 and the third cracked dry gas 129 to ethane cracking treatment to obtain ethylene 149; wherein the reaction pressure is 0.10 MPa, the reaction temperature is 820° C., and the residence time is 0.25 to 0.4 s;

[0091] S7, gas separation of the first cracked liquefied gas 142, the second cracked liquefied gas 138 and the third cracked liquefied gas 130 to obtain the first propylene 150, propane 135 and C4 mixed hydrocarbons 136; propane dehydrogenation of the propane 135 to obtain the second propylene 150, and the C4 mixed hydrocarbons 136 are subjected to superposition reaction to obtain superposition oil 154 and remaining C4 hydrocarbons 155; the superposition oil 154 is returned to the third catalytic cracking of step S4, and the remaining C4 hydrocarbons 155 are subjected to light hydrocarbon conversion to produce propane to obtain propane conversion gas 156, and the propane conversion gas 156 is returned to the gas separation of step S7. Wherein, the reaction temperature of propane dehydrogenation is 600°C, the reaction pressure is 0.2MPa, the reaction time is 50h, and the propane mass space velocity is 5h -1 ; The superposition reaction temperature is 250℃, the reaction pressure is 5MPa, and the mass space velocity is 3h -1 ; The reaction temperature for light hydrocarbon conversion to propane is 380°C, the reaction pressure is 0.8MPa, and the mass space velocity is 0.9h -1 .

[0092] The products obtained in Example 1 and their indicators are listed in the following Table 1.

[0093] Under the production condition that the total crude oil processing volume is 10 million tons / year, the raw material and product indicators of the above-mentioned embodiment are listed in the following Table 1:

[0094] Table 1

[0095] Example 1 Carbon content Total crude oil 100 84.81％ Yield of main products, % Chemicals 65.58 57.05％ Ethylene 19.90 17.06％ Propylene 30.35 26.01％ C6-C8 Aromatics 15.33 13.98％ benzene 2.81 2.59％ Toluene 6.28 5.73％ Mixed xylene 6.24 5.65％ Fuel oil 11.64 10.77％

[0096] The yield in Table 1 is the percentage obtained by dividing the weight of the product by the weight of the crude oil; the data in Table 1 show that of the 84.81 tons of carbon contained in every 100 tons of crude oil, 57.05 tons are converted into chemical products, 10.77 tons are converted into fuel oil, and the remaining 16.99 tons are converted into flue gas after providing heat.

[0097] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0098] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0099] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A crude oil processing method for maximizing the production of chemical products and concurrently producing marine fuel, characterized in that: The method comprises the following steps: S1, separating crude oil into naphtha fraction, straight-run diesel fraction and atmospheric residue fraction; S2, hydrogenating the atmospheric residue fraction to obtain residue hydrogenated diesel and residue hydrogenated heavy oil; separating a first stream of residue hydrogenated heavy oil and a second stream of residue hydrogenated heavy oil from the residue hydrogenated heavy oil, subjecting the first stream of residue hydrogenated heavy oil to a first catalytic cracking to obtain a first cracked dry gas, a first cracked liquefied gas, a first cracked gasoline, a first cracked diesel and a cracked oil slurry; mixing the second stream of residue hydrogenated heavy oil with the cracked oil slurry to obtain a marine fuel; S3, hydrofining the straight-run diesel fraction and the residual oil hydrogenated diesel to obtain refined diesel; performing a second catalytic cracking on the refined diesel to obtain a second cracked dry gas, a second cracked liquefied gas, a second cracked gasoline and a second cracked diesel; S4, subjecting the naphtha fraction and the first pyrolysis gasoline to a third catalytic cracking to obtain a third pyrolysis dry gas, a third pyrolysis liquefied gas and a third pyrolysis gasoline; S5, hydrocracking the first pyrolysis diesel and the second pyrolysis diesel to obtain hydrocracking gasoline and hydrocracking diesel; returning the hydrocracking diesel to the first catalytic cracking of step S2; subjecting the hydrocracking gasoline, the second pyrolysis gasoline and the third pyrolysis gasoline to pyrolysis gasoline hydrogenation treatment and pyrolysis gasoline extraction treatment to obtain C6-C8 aromatics, raffinate oil and heavy aromatics above C9; returning the raffinate oil to the third catalytic cracking of step S4; returning the heavy aromatics to the hydrocracking of step S5; S6, subjecting the first cracked dry gas, the second cracked dry gas and the third cracked dry gas to ethane cracking treatment to obtain ethylene; S7, the first cracked liquefied gas, the second cracked liquefied gas and the third cracked liquefied gas are subjected to gas separation to obtain a first stream of propylene, propane and C4 mixed hydrocarbons; the propane is subjected to propane dehydrogenation to obtain a second stream of propylene, and the C4 mixed hydrocarbons are subjected to superposition reaction to obtain superposition oil and remaining C4 hydrocarbons; the superposition oil is returned to the third catalytic cracking of step S4, the remaining C4 hydrocarbons are subjected to light hydrocarbon conversion to produce propane to obtain propane conversion gas, and the propane conversion gas is returned to the gas separation of step S7.

2. The method according to claim 1, wherein: In step S7, the gas fraction also obtains at least one of 1-butene, 2-butene and butadiene.

3. The method according to claim 1, wherein: In step S1, the cutting point between the naphtha fraction and the straight-run diesel fraction is any temperature between 175-205°C, and the cutting point between the straight-run diesel fraction and the atmospheric residue fraction is any temperature between 335-370°C.

4. The method according to claim 1, wherein: In step S2, the reaction conditions of the hydrotreatment include: reaction temperature of 300-460°C, reaction pressure of 6-25MPa, hydrogen-oil volume ratio of (100-1500):1; the separation cutting point of hydrogenated diesel and residual oil hydrogenated heavy oil is any temperature between 335-370°C; The first catalytic cracking conditions include: a reaction temperature of 400-650°C, a reaction pressure of 0.05-1 MPa, a catalyst-oil weight ratio of (5-50):1; a separation cut point of the first cracked dry gas and the first cracked liquefied gas at any temperature between 14-16°C, a separation cut point of the first cracked liquefied gas and the first cracked gasoline at any temperature between 38-62°C, and a separation cut point of the first cracked gasoline and the first cracked diesel at any temperature between 175-205°C; The weight ratio between the first stream of residual oil hydrogenated heavy oil and the second stream of residual oil hydrogenated heavy oil is (1-15):

1.

5. The method according to claim 1, wherein: In step S3, the reaction conditions of the hydrotreating include: reaction temperature of 200-400° C., reaction pressure of 2-16 MPa, and hydrogen-to-oil volume ratio of (400-1000):1; The second catalytic cracking conditions include: a reaction temperature of 500-750°C, a reaction pressure of 0.05-1MPa, a catalyst-oil weight ratio of (5-100):1, preferably (10-50):1; the separation cut point of the second cracked dry gas and the second cracked liquefied gas is any temperature between 14-16°C, the separation cut point of the second cracked liquefied gas and the second cracked gasoline is any temperature between 38-62°C, and the separation cut point of the second cracked gasoline and the second cracked diesel is any temperature between 175-205°C.

6. The method according to claim 1, wherein: In step S4, the third catalytic cracking conditions include: a reaction temperature of 500-750°C, a reaction pressure of 0.05-1MPa, a catalyst-oil weight ratio of (5-100):1, preferably (10-50):1; the separation cut point of the third cracked dry gas and the third cracked liquefied gas is any temperature between 14-16°C, and the separation cut point of the third cracked liquefied gas and the third cracked gasoline is any temperature between 38-62°C.

7. The method according to claim 1, wherein: In step S5, the reaction conditions of the hydrocracking treatment include: reaction temperature of 260-500°C, hydrogen partial pressure of 3-10 MPa, volume space velocity of 0.5-6 h -1 ; The separation cut point of hydrocracked gasoline and hydrocracked diesel is any temperature between 175-205℃; The reaction conditions of the pyrolysis gasoline hydrotreatment include: the reaction temperature of the hydrogenation unit is 300-400°C, the reaction pressure is 4-16MPa, and the volume ratio of hydrogen to oil is (300-1000):

1. The conditions of the pyrolysis gasoline extraction include: the temperature is 20-100°C, the pressure is 0.05-0.5MPa, and the weight ratio of the extraction solvent to the raw oil is (0.5-2.5):

1.

8. The method according to claim 1, wherein: In step S6, the reaction conditions of the ethane cracking treatment include: reaction pressure of 0.10-0.25 MPa, reaction temperature of 810-870° C., and residence time of 0.25-0.4 s.

9. The method according to claim 1, wherein: In step S7, the reaction conditions of the propane dehydrogenation treatment include: reaction temperature 400-700°C, reaction pressure 0.05-1 MPa, reaction time 40-60 h, propane mass space velocity 2-9 h -1 ; The reaction conditions of the superposition reaction include: reaction temperature of 40-350°C, preferably 200-300°C, reaction pressure of 0.5-10 MPa, mass space velocity of 0.2-20 h -1 ; The separation cutting point of the superimposed oil and the remaining C4 hydrocarbons is any temperature between 30-65°C; The reaction conditions for converting light hydrocarbons to propane include: a reaction temperature of 250 to 550° C., a reaction pressure of 0.1 to 2 MPa, and a mass space velocity of 0.1 to 3 h -1 .

10. A crude oil processing system for maximizing the production of chemicals and also producing marine fuel, characterized in that: The system includes: an atmospheric pressure unit, a third catalytic cracking unit, a diesel hydrofining unit, a residual oil hydrogenation unit, an ethane cracking unit, a gas separation unit, a second catalytic cracking unit, a first catalytic cracking unit, a pyrolysis gasoline hydrogenation unit, a pyrolysis gasoline extraction unit, a catalytic diesel hydrocracking aromatics unit, a propane dehydrogenation unit, a superposition unit and a light hydrocarbon conversion propane unit; The naphtha fraction outlet of the atmospheric pressure device is communicated with the third catalytic cracking inlet of the third catalytic cracking device; the third cracked dry gas outlet of the third catalytic cracking device is communicated with the cracked dry gas inlet of the ethane cracking device; The straight-run diesel fraction outlet of the atmospheric pressure unit is connected to the first diesel hydrofining inlet of the diesel hydrofining unit, and the refined diesel outlet of the diesel hydrofining unit is connected to the refined diesel inlet of the second catalytic cracking unit; The atmospheric residue fraction outlet of the atmospheric pressure unit is communicated with the atmospheric residue fraction inlet of the residue hydrogenation unit, the residue hydrogenated diesel outlet of the residue hydrogenation unit is communicated with the second diesel hydrogenation refining inlet of the diesel hydrotreating unit, the first residue hydrogenated heavy oil outlet of the residue hydrogenation unit is communicated with the residue hydrogenated heavy oil inlet of the first catalytic cracking unit, and the second residue hydrogenated heavy oil outlet of the residue hydrogenation unit is communicated with the cracked oil slurry outlet of the first catalytic cracking unit; the first cracked dry gas outlet of the first catalytic cracking unit and the second cracked dry gas outlet of the second catalytic cracking unit are respectively communicated with the connecting pipeline between the third cracked dry gas outlet of the third catalytic cracking unit and the cracked dry gas inlet of the ethane cracking unit; The second cracked liquefied gas outlet of the second catalytic cracking device is communicated with the first cracked liquefied gas inlet of the gas separation device, the third cracked liquefied gas outlet of the third catalytic cracking device and the first cracked liquefied gas outlet of the first catalytic cracking device are respectively communicated with the connecting pipeline between the second cracked liquefied gas outlet and the first cracked liquefied gas inlet; the third cracked gasoline outlet of the third catalytic cracking device is communicated with the cracked gasoline inlet of the cracked gasoline hydrogenation device, the second cracked gasoline outlet of the second catalytic cracking device is communicated with the connecting pipeline between the third cracked gasoline outlet and the first cracked gasoline inlet, and the first cracked gasoline outlet of the first catalytic cracking device is communicated with the third catalytic cracking inlet; The first cracked diesel outlet of the first catalytic cracking unit is communicated with the first cracked diesel inlet of the catalytic diesel hydrocracking unit to produce aromatics, and the second cracked diesel outlet of the second catalytic cracking unit is communicated with the connecting pipeline between the first cracked diesel outlet and the first cracked diesel inlet; the hydrocracking gasoline outlet of the catalytic diesel hydrocracking unit to produce aromatics is communicated with the pyrolysis gasoline inlet of the pyrolysis gasoline hydrogenation unit; the hydrocracking diesel outlet of the catalytic diesel hydrocracking unit to produce aromatics is communicated with the first catalytic cracking inlet of the first catalytic cracking unit; The propane outlet of the gas separation device is connected to the propane inlet of the propane dehydrogenation device, and the first propylene outlet of the gas separation device is connected to the second propylene outlet of the propane dehydrogenation device; The product outlet of the pyrolysis gasoline hydrogenation device is connected to the raw material inlet of the pyrolysis gasoline extraction device; The raffinate outlet of the pyrolysis gasoline extraction device is connected to the connecting pipeline between the naphtha fraction outlet and the third catalytic cracking inlet; the heavy aromatics outlet of the pyrolysis gasoline extraction device is connected to the heavy aromatics inlet of the catalytic diesel hydrocracking aromatics production device; The C4 mixed hydrocarbon outlet of the gas separation device is connected to the C4 mixed hydrocarbon inlet of the superposition device, and the superposition oil outlet of the superposition device is connected to the connecting pipeline between the naphtha fraction outlet and the third catalytic cracking inlet; the remaining C4 hydrocarbon outlet of the superposition device is connected to the remaining C4 hydrocarbon inlet of the light hydrocarbon conversion to propane device, and the propane conversion gas outlet of the light hydrocarbon conversion to propane device is connected to the second cracked liquefied gas inlet of the gas separation device.

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