Method and system for producing chemical material containing ethylene based on constant linear velocity fluidized bed reactor

Abstract

The invention relates to a method and a system for producing chemical materials including ethylene based on a constant linear velocity fluidized bed reactor, and the method comprises the following steps: (1) carrying out contact reaction on raw oil and a shape-selective molecular sieve catalyst in the constant linear velocity fluidized bed reactor to obtain an oil agent mixture; (2) separating the oil agent mixture to obtain reaction oil gas and a spent catalyst; and (3) separating the reaction oil gas in an oil-gas separation system to obtain chemical materials including ethylene, C4 olefin and the like. In a constant-linear-speed fluidized bed reactor, light petroleum hydrocarbons such as diesel oil are contacted with a shape-selective molecular sieve catalyst, and self-heat balance is maintained through regeneration flue gas circulation to produce ethylene, propylene and the like. According to the method disclosed by the invention, heavy oil such as naphtha, wax oil and residual oil can be processed while light hydrocarbon such as diesel oil is processed, the yield of ethylene and propylene is high, self-heating balance can be realized, the problem of excessive diesel oil production capacity of a refinery plant is solved, and the defects of chemical materials are made up.

Description

Technical Field

[0001] The present invention relates to the technical field of catalytic cracking of hydrocarbons, and in particular to a method and system for producing chemical materials including ethylene based on a constant linear velocity fluidized bed reactor. Background Art

[0002] In recent years, the diesel-to-gasoline ratio in the refined oil market has been decreasing. After reaching a peak of 176Mt in 2014, diesel consumption has experienced zero or negative growth. According to statistics, the unit mileage emissions of a heavy-duty diesel vehicle are about 150 times that of a light-duty gasoline vehicle at the same stage, and the annual emissions are about 750 times that of a light-duty gasoline vehicle at the same stage. This pollution situation further restricts the development of diesel vehicles. It is expected that by 2025, diesel consumption will be reduced to 168Mt, and the diesel-to-gasoline ratio will be reduced from the current 1.4 to less than 1. This will mean that there will be a surplus of hundreds of millions of tons of diesel products, and the high particulate matter emissions of diesel engines will further restrict the use of diesel, and there will be a surplus of millions of tons of diesel for vehicles in tens of millions of tons of refineries. Reducing the diesel-to-gasoline ratio of refinery products and finding a way out for diesel have become urgent issues to be solved. Straight-run diesel accounts for about 50% of the total diesel volume. Reducing the output of straight-run diesel or converting it into other high-value-added products to adapt to future changes in diesel demand is of great significance to ensuring the balance of supply and demand in my country's refined oil market.

[0003] For the conversion of straight-run diesel, usually less than 10% of light diesel can be blended into ethylene cracking raw materials. However, compared with other light raw materials, the steam cracking olefin yield of straight-run diesel is lower and the decoking cycle is short. In addition, hydrocracking can process straight-run diesel, with a hydrogen consumption of 2.5%, a naphtha yield of 50% to 60%, and a liquefied gas yield of 4% to 5%. In recent years, domestic refineries have also adopted conventional catalytic cracking units to blend straight-run diesel in order to reduce the diesel-gasoline ratio. For example, the conventional catalytic cracking unit of Sinopec Hainan Refining and Chemical Co., Ltd. blends the three-line straight-run diesel, with a gasoline yield of 41%, but the volume fraction of propylene in the liquefied gas decreases by 0.52 percentage points and the volume fraction of isobutylene decreases by 0.12 percentage points, which is not conducive to increasing the production of low-carbon olefins.

[0004] The catalytic cracking of straight-run diesel alone or the catalytic cracking technology has progressed slowly. On the one hand, straight-run diesel has always been of high value as a high-cetane number vehicle fuel, with large usage and limited resources. On the other hand, the yield of catalytic cracking of straight-run diesel to produce gasoline or chemical materials such as ethylene and propylene is low. In addition, the coke production of straight-run diesel catalytic cracking is low, which is not enough to maintain the conventional fluidized bed catalytic cracking of self-thermal equilibrium, and the catalytic cracking requires a higher temperature.

[0005] Existing research at home and abroad has mainly focused on improving conversion rate and compensating for heat balance. For example, China National Petroleum Corporation's patent CN111607425A discloses a method for cracking straight-run diesel, that is, straight-run diesel with alkaline nitrogen removed by dihydrogen phosphate and inert gases such as nitrogen enter a fixed bed or moving bed reactor equipped with activated pretreated ZSM-5 nanomolecular sieve for catalytic cracking, and patent CN111718751A discloses a method for preparing a ZSM-5 nanomolecular sieve catalyst modified by transition metals and / or non-metals in the method. As described in the two patents, straight-run diesel uses a fixed bed reactor to heat the reaction temperature up to 600°C to achieve a diesel conversion rate of up to 80.16% and a light olefin yield of 34.13%; however, its one-way cycle is as short as 47 hours, and the short reaction cycle requires frequent switching of reactors, while the one-way cycle of a moving bed reactor is extended to 78 hours, but the operation is difficult.

[0006] Sinopec's patents CN104418685B and CN104418686A both disclose a method for catalytic cracking of straight-run diesel in a riser reactor with methane as a diluent and the spent agent exchanging heat with flue gas. Patent CN104418686A also discloses a technology for extracting aromatics from cracked gasoline and steam cracking of H2+C1-C4 alkanes. As described in the two patents, the use of mature fluidized bed technology can achieve continuous reaction-regeneration and solve the heat balance problem by setting up a spent agent and flue gas heat exchanger. At a reaction temperature of up to 630°C and a catalyst / oil mass ratio of 18, the diesel conversion rate of up to 83.83% and the ethylene and propylene yields of 16.52% and 35.19% were achieved through C4 recycling; however, the heat exchange between the spent agent and flue gas requires the addition of a heat exchanger, which is complex in process, high in equipment investment, and low in heat exchange efficiency. In addition, the flue gas contains a certain amount of oxygen and the spent agent is not fully burned, which is prone to tail combustion and other hidden dangers.

[0007] Therefore, in view of the current diesel surplus, how to solve the problem of diesel cracking, so that diesel can be better converted into high-value products through catalytic cracking reactions, and increase the yield of ethylene and propylene while reducing the coke yield is a technical problem that needs to be solved urgently. Summary of the invention

[0008] The present invention provides a method and system for producing chemical materials including ethylene based on an isolinear fluidized bed reactor, the purpose of which is to enable light oil such as diesel to be better converted into high-value products such as ethylene and propylene through catalytic cracking reactions in an isolinear fluidized bed reactor.

[0009] In a first aspect, the present invention relates to a method for producing a chemical material including ethylene based on an isolinear fluidized bed reactor, the method comprising the following steps:

[0010] (1) contacting and reacting the crude oil with a shape-selective molecular sieve catalyst in a constant linear velocity fluidized bed reactor to obtain an oil-agent mixture;

[0011] The shape-selective molecular sieve catalyst comprises a shape-selective molecular sieve, and the shape-selective molecular sieve is selected from a molecular sieve with a ten-membered ring structure; the catalyst in the isolinear fluidized bed reactor flows upward, and the inner diameter of the reaction section decreases from top to bottom;

[0012] (2) separating the oil mixture to obtain reaction oil gas and a catalyst to be produced;

[0013] The oil mixture is subjected to cyclone separation and sedimentation to obtain a first reaction oil gas and a catalyst to be regenerated with residual oil gas; the catalyst to be regenerated with residual oil gas is subjected to stripping to obtain a second reaction oil gas and the catalyst to be regenerated; the reaction oil gas includes the first reaction oil gas and the second reaction oil gas;

[0014] (3) separating the reaction oil and gas in an oil and gas separation system to obtain chemical materials including ethylene, C4 olefins, light gasoline fraction, heavy aromatic fraction and slurry oil;

[0015] (4) allowing the catalyst to be regenerated to enter a regenerator for regeneration in an oxygen-containing atmosphere to obtain a regenerated catalyst and flue gas; returning at least a portion of the regenerated catalyst to the isolinear fluidized bed reactor for recycling, and returning at least a portion of the flue gas to the regenerator for recycling.

[0016] Optionally, in step (1):

[0017] The ten-membered ring structure molecular sieve is selected from a combination of one or more of ZSM-5 molecular sieve, ZSM-11 molecular sieve, ZSM-12 molecular sieve, ZSM-23 molecular sieve, ZSM-35 molecular sieve, ZSM-38 molecular sieve, ZSM-48 molecular sieve and ZRP-5 molecular sieve, and the average pore size of the ten-membered ring structure molecular sieve is 0.5-0.6 nm; and / or,

[0018] The shape-selective molecular sieve catalyst further comprises an oxide and optional clay, wherein the oxide is selected from a combination of one or more of aluminum oxide, silicon oxide and modified oxide; the modified oxide is selected from one or more metal element oxides and / or non-metal element oxides in Group IA, Group IIA, Group VA, Group IIIB and Group VIII;

[0019] The ten-membered ring structure molecular sieve is a molecular sieve obtained by modifying a mesoporous molecular sieve with the modified oxide;

[0020] The mass proportion of the ten-membered ring structure molecular sieve in the shape-selective molecular sieve catalyst is 40-70%, and the mass proportion of the modified oxide in the shape-selective molecular sieve catalyst is 1.0-10.0%;

[0021] and / or,

[0022] The average particle size of the shape-selective molecular sieve catalyst is 40 to 150 microns.

[0023] Optionally, the feedstock oil is diesel, and the diesel is fed into the isolinear fluidized bed reactor from the lower part of the reaction section;

[0024] Preferably, at least part of one or more of the C4 olefins, the light gasoline fraction, the heavy aromatic fraction and the slurry oil is fed into the isolinear fluidized bed reactor through the reaction section for recycling;

[0025] The feed positions of the C4 olefins, the light gasoline fraction and the heavy aromatic fraction are located below the feed position of the diesel, or are fed through the feed position of the diesel; the feed position of the oil slurry is located above the feed position of the diesel.

[0026] Optionally, the feedstock oil includes diesel and heavy oil, the diesel is fed into the isolinear fluidized bed reactor from the lower part of the reaction section, and the heavy oil is fed into the isolinear fluidized bed reactor from the middle part of the reaction section;

[0027] Preferably, at least part of one or more of the C4 olefins, the light gasoline fraction, the heavy aromatic fraction and the slurry oil is fed into the isolinear fluidized bed reactor through the reaction section for recycling;

[0028] The feed positions of the C4 olefins, the light gasoline fraction and the heavy aromatic fraction are located below the feed position of the diesel, or are fed through the feed position of the diesel; and the oil slurry is fed through the feed position of the heavy oil.

[0029] Optionally, the feedstock oil is diesel, and the diesel is fed into the isolinear fluidized bed reactor from the lower part of the reaction section;

[0030] Furthermore, step (1) further comprises:

[0031] The heavy oil is contacted and reacted with a shape-selective molecular sieve catalyst in a riser reactor;

[0032] In step (2), a portion of the oil mixture is derived from the contact reaction between the diesel and the shape-selective molecular sieve catalyst, and another portion is derived from the contact reaction between the heavy oil and the shape-selective molecular sieve catalyst; in step (4), a portion of the regenerated catalyst is returned to the isolinear fluidized bed reactor for recycling, and another portion of the regenerated catalyst is returned to the riser reactor for recycling;

[0033] Preferably, at least part of one or more of the C4 olefins, the light gasoline fraction, the heavy aromatic fraction and the slurry oil is fed into the riser reactor for recycling;

[0034] The feed positions of the C4 olefins, the light gasoline fraction and the heavy aromatic fraction are located below the feed position of the heavy oil, and the slurry oil is fed through the feed position of the heavy oil.

[0035] Optionally, the diesel is selected from a combination of one or more of straight-run diesel, catalytic cracking diesel and hydrogenated diesel; and / or,

[0036] The boiling point of the diesel is 180-380°C and the density is less than or equal to 850kg / m 3 .

[0037] Optionally, the heavy oil is wax oil and / or residual oil.

[0038] Optionally, the conditions for the contact reaction between the diesel and the shape-selective molecular sieve catalyst in step (1) include:

[0039] The reaction temperature is 620-720° C., the reaction pressure is 0.2-0.5 MPa, the reaction time is 3.0-7.0 seconds, and the weight ratio of the shape-selective molecular sieve catalyst to the diesel is (6-10):1;

[0040] The diesel is fed into the isolinear fluidized bed reactor under fluidization of a fluidizing medium;

[0041] The fluidizing medium is atomized water, and the mass ratio of the atomized water to the diesel is (0.20-0.30):1;

[0042] The oil and gas linear velocity in the reaction zone is 1.0-2.0 m / s;

[0043] and / or,

[0044] The method further comprises the following steps before step (1):

[0045] Preheating the feedstock oil to a preheating temperature of 200 to 400° C., preferably 260 to 360° C.;

[0046] The preheating is carried out by heating in a heating furnace, or by exchanging heat between the crude oil and the chemical material obtained from step (3).

[0047] Optionally, the conditions for the contact reaction between the heavy oil and the shape-selective molecular sieve catalyst in the riser reactor include:

[0048] The reaction temperature is 620-720° C., the reaction pressure is 0.2-0.5 MPa, the weight ratio of the shape-selective molecular sieve catalyst to the heavy oil is (6-10):1, and the reaction time is 3.0-7.0 seconds;

[0049] The heavy oil is fed into the riser reactor under fluidization of a fluidizing medium;

[0050] The fluidizing medium is atomized water, and the mass ratio of the atomized water to the heavy oil is (0.20-0.30):1;

[0051] The oil and gas linear velocity in the riser reactor is 2.0-12.0 m / s.

[0052] Optionally, in step (3), the oil-gas separation system is selected from a combination of one or more of two or more fractionation towers with a theoretical plate number greater than 20, an absorption stabilization system, and a gas separation system;

[0053] Propylene, H2 and C1-C4 alkanes, a BTX fraction and a methyl naphthalene oil fraction are also obtained through the separation described in step (3).

[0054] Optionally, in step (4):

[0055] The regeneration temperature of the regenerator is 640-780°C and the pressure is 0.3-0.6MPa;

[0056] The circulation rate of the regenerated catalyst is 150-200 kg / (m 2 ·Second);

[0057] The regeneration atmosphere in the regenerator is selected from one of air, oxygen-enriched and pure oxygen;

[0058] The flue gas is optionally returned to the regenerator for recycling after heat exchange, and the temperature of the flue gas returned to the regenerator for recycling is 340-580°C.

[0059] In a second aspect, the present invention relates to a system for producing chemical materials including ethylene based on an isolinear fluidized bed reactor, the system comprising an isolinear fluidized bed reactor, a cyclone separator, a settler, an oil-gas separation system and a regenerator;

[0060] The isolinear fluidized bed reactor is provided with a reactor pre-lifting section, a reactor reaction section, a reactor outlet section and a catalyst stripping section; the catalyst in the isolinear fluidized bed reactor flows upward; the cyclone separator and the settler are located above the catalyst stripping section; the inner diameter of the reactor outlet section is smaller than that of the reactor reaction section;

[0061] The outlet of the pre-lifting section of the reactor is connected to the inlet of the reaction section of the reactor, and the outlet of the reaction section of the reactor is connected to the inlet of the outlet section of the reactor;

[0062] The reactor reaction section is a variable diameter reaction section, and the inner diameter of the reactor reaction section gradually decreases from top to bottom; a light hydrocarbon feedstock oil inlet and a first atomizing steam inlet are arranged at the lower part of the reactor reaction section, and the light hydrocarbon feedstock oil inlet and the first atomizing steam inlet are connected;

[0063] The oil agent outlet of the reactor outlet section is connected to the oil agent inlet of the cyclone separator, the catalyst outlet of the cyclone separator is connected to the inlet of the settler, and the oil and gas outlet of the cyclone separator is connected to the oil and gas inlet of the oil and gas separation system;

[0064] The outlet of the settler is connected to the inlet of the catalyst stripping section, the catalyst outlet of the catalyst stripping section is connected to the inlet of the regenerator to be regenerated catalyst, and the oil and gas outlet of the catalyst stripping section is connected to the oil and gas separation system;

[0065] The regenerator is provided with an oxygen-containing regeneration gas inlet and a flue gas outlet, the flue gas outlet is connected with the oxygen-containing regeneration gas inlet through a flue gas circulation system, the regeneration catalyst outlet of the regenerator is connected with the catalyst inlet of the reactor pre-lift section through a first regeneration agent delivery pipeline, and the bottom of the reactor pre-lift section is provided with a first fluidizing medium inlet;

[0066] The oil-gas separation system is provided with an ethylene outlet, a propylene outlet, an H2 and C1-C4 alkane outlet, a C4 olefin outlet, a light gasoline fraction outlet, a BTX fraction outlet, a heavy aromatic fraction outlet, a methyl naphthalene oil fraction outlet and an oil slurry outlet;

[0067] Preferably, the oil and gas outlet of the cyclone separator is connected to the oil and gas inlet of the oil and gas separation system through a reaction oil and gas pipeline, and the oil and gas outlet of the catalyst stripping section is connected to the oil and gas inlet of the oil and gas separation system through the reaction oil and gas pipeline;

[0068] Preferably, a stripping medium inlet is provided at the lower portion of the catalyst stripping section;

[0069] Preferably, the catalyst outlet of the catalyst stripping section is connected to the catalyst inlet to be regenerated of the regenerator through a regenerated catalyst delivery pipeline;

[0070] Preferably, a first heavy feedstock oil inlet and a second atomizing steam inlet are provided in the middle of the reaction section of the reactor, and the first heavy feedstock oil inlet is connected to the second atomizing steam inlet;

[0071] Preferably, the reactor reaction section is provided with a first refining inlet and a second refining inlet, wherein the first refining inlet and the second refining inlet are respectively located below and above the light hydrocarbon feedstock oil inlet;

[0072] The C4 olefin outlet, the light gasoline fraction outlet and the heavy aromatic fraction outlet are respectively connected to the first refining inlet, or are respectively connected to the light hydrocarbon feedstock oil inlet; the slurry oil outlet is connected to the second refining inlet, or is connected to the first heavy feedstock oil inlet.

[0073] Optionally, the system is further provided with a riser reactor, the riser reactor is provided with a second heavy feedstock oil inlet and a third atomizing steam inlet, and the second heavy feedstock oil inlet is connected to the third atomizing steam inlet;

[0074] The regenerated catalyst outlet of the regenerator is connected to the catalyst inlet at the bottom of the riser reactor through a second regeneration agent delivery pipeline, and a second fluidizing medium inlet is also provided at the bottom of the riser reactor;

[0075] The oil agent outlet of the riser reactor is connected to the oil agent inlet of the cyclone separator;

[0076] Preferably, the riser reactor is provided with a third recycle port, the third recycle port is located below the second heavy feedstock oil inlet, the C4 olefin outlet, the light gasoline fraction outlet and the heavy aromatic fraction outlet are respectively connected to the third recycle port, and the slurry oil outlet is connected to the second heavy feedstock oil inlet.

[0077] Beneficial effects:

[0078] The present invention allows the crude oil to contact and react with the shape-selective molecular sieve catalyst in a constant linear velocity fluidized bed reactor. By controlling the inner diameter of the reaction section to decrease from top to bottom, the catalyst flows upward, and the feed position of the crude oil is controlled, so that light crude oil such as diesel can be better converted into low-carbon olefins, and the yield of ethylene and propylene is significantly improved. Self-heating balance can be achieved by returning the flue gas after regeneration to the regenerator for recycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Figure 1It is a structural schematic diagram of a specific embodiment of a system for producing chemical materials including ethylene based on a constant linear velocity fluidized bed reactor of the present invention;

[0080] Figure 2 It is a structural schematic diagram of another specific embodiment of a system for producing chemical materials including ethylene based on a constant linear velocity fluidized bed reactor of the present invention;

[0081] Description of Reference Numerals

[0082] I Reactor pre-lifting section II Reactor reaction section III Reactor outlet section

[0083] IV Settler IV-1 Cyclone separator IV-2 Catalyst stripping section

[0084] 1 Constant linear velocity fluidized bed reactor 2 Light hydrocarbon feedstock inlet 3 First atomizing steam inlet

[0085] 4First fluidizing medium inlet 5Reaction oil and gas pipeline 6Oil and gas separation system

[0086] 7 Ethylene outlet 8 Propylene outlet 9 H2 and C1-C4 alkane outlet

[0087] 10C4 olefin export 11Light gasoline fraction export 12BTX fraction export

[0088] 13 Heavy aromatic fraction outlet 14 Methyl naphthalene oil fraction outlet 15 Slurry oil outlet

[0089] 16 First heavy crude oil inlet 17 Second atomizing steam inlet 18 Stripping medium inlet

[0090] 19 Regenerated agent delivery pipeline 20 Regenerator 21 Oxygen-containing regeneration gas inlet

[0091] 22 First regeneration agent delivery pipeline 23 Flue gas outlet 24 Flue gas circulation system

[0092] 25 Riser reactor 26 Second fluidizing medium inlet 27 Second regeneration agent delivery pipeline

[0093] 28 second heavy crude oil inlet 29 third atomizing steam inlet. DETAILED DESCRIPTION

[0094] The present application is further described in detail below through the accompanying drawings and embodiments. Through these descriptions, the characteristics and advantages of the present application will become clearer and more specific.

[0095] The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise noted.

[0096] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0097] In a first aspect, the present invention relates to a method for producing a chemical material including ethylene based on an isolinear fluidized bed reactor, the method comprising the following steps:

[0098] (1) contacting and reacting the crude oil with a shape-selective molecular sieve catalyst in a constant linear velocity fluidized bed reactor to obtain an oil-agent mixture;

[0099] The shape-selective molecular sieve catalyst comprises a shape-selective molecular sieve, and the shape-selective molecular sieve is selected from a molecular sieve with a ten-membered ring structure; the catalyst in the isolinear fluidized bed reactor flows upward, and the inner diameter of the reaction section decreases from top to bottom;

[0100] (2) separating the oil mixture to obtain reaction oil gas and a catalyst to be produced;

[0101] The oil mixture is subjected to cyclone separation and sedimentation to obtain a first reaction oil gas and a catalyst to be regenerated with residual oil gas; the catalyst to be regenerated with residual oil gas is subjected to stripping to obtain a second reaction oil gas and the catalyst to be regenerated; the reaction oil gas includes the first reaction oil gas and the second reaction oil gas;

[0102] (3) separating the reaction oil and gas in an oil and gas separation system to obtain chemical materials including ethylene, C4 olefins, light gasoline fraction, heavy aromatic fraction and slurry oil;

[0103] (4) allowing the catalyst to be regenerated to enter a regenerator for regeneration in an oxygen-containing atmosphere to obtain a regenerated catalyst and flue gas; returning at least a portion of the regenerated catalyst to the isolinear fluidized bed reactor for recycling, and returning at least a portion of the flue gas to the regenerator for recycling.

[0104] It should be noted that the catalyst in the constant linear velocity fluidized bed reactor may also flow downward, preferably upward; the flammable gases such as oil and gas entrained by the catalyst can be removed by stripping in step (2). In the method of the present invention, the crude oil and the shape-selective molecular sieve catalyst are contacted and reacted in the constant linear velocity fluidized bed reactor, the catalyst flows upward in the constant linear velocity fluidized bed reactor, and the inner diameter of the reaction section of the constant linear velocity fluidized bed reactor decreases from top to bottom. Such a flow mode and inner diameter setting enable the crude oil to be better catalytically cracked into high-value products such as ethylene and propylene in the constant linear velocity fluidized bed reactor.

[0105] Moreover, the self-heating balance is maintained by circulating the regenerated flue gas, so that chemical materials such as ethylene can be better produced, and the yield of high-value products such as ethylene and propylene is high. The method of the present invention can process light oils such as diesel and heavy oils such as naphtha, wax oil, and residual oil at the same time, which not only solves the problem of excess diesel production capacity in refineries, but also makes up for the shortage of chemical materials.

[0106] According to a specific implementation of the method according to the first aspect of the present invention, in step (1):

[0107] The ten-membered ring structure molecular sieve is selected from a combination of one or more of ZSM-5 molecular sieve, ZSM-11 molecular sieve, ZSM-12 molecular sieve, ZSM-23 molecular sieve, ZSM-35 molecular sieve, ZSM-38 molecular sieve, ZSM-48 molecular sieve and ZRP-5 molecular sieve, and the average pore size of the ten-membered ring structure molecular sieve is 0.5-0.6 nm; and / or,

[0108] The shape-selective molecular sieve catalyst further comprises an oxide and optional clay, wherein the oxide is selected from a combination of one or more of aluminum oxide, silicon oxide and modified oxide; the modified oxide is selected from one or more metal element oxides and / or non-metal element oxides in Group IA, Group IIA, Group VA, Group IIIB and Group VIII;

[0109] The ten-membered ring structure molecular sieve is a molecular sieve obtained by modifying a mesoporous molecular sieve with the modified oxide;

[0110] The mass proportion of the ten-membered ring structure molecular sieve in the shape-selective molecular sieve catalyst is 40-70%, and the mass proportion of the modified oxide in the shape-selective molecular sieve catalyst is 1.0-10.0%;

[0111] and / or,

[0112] The average particle size of the shape-selective molecular sieve catalyst is 40 to 150 microns.

[0113] It should be noted that the shape-selective molecular sieve is modified by the modified oxide; the oxide other than the modified oxide may include heat-resistant binders such as aluminum oxide and silicon oxide and / or optional natural porous carrier materials such as clay. Preferably, the shape-selective molecular sieve catalyst is a composite composed of metal and / or non-metal modified ZSM-5 series mesoporous molecular sieves with MFI structure, binders such as aluminum oxide and silicon oxide, and optional natural porous carrier materials such as clay.

[0114] It should be noted that when producing chemical materials such as ethylene in a variable diameter constant linear velocity fluidized bed reactor based on the method of the present invention, using a catalyst containing a shape-selective molecular sieve with a ten-membered ring structure, such as an MFI molecular sieve with a ten-membered ring structure, can further and better catalyze the reaction of crude oil into high-value products such as ethylene and propylene, thereby increasing the yield of products such as low-carbon olefins.

[0115] According to a first specific implementation of the method of the first aspect of the present invention, the feedstock oil is diesel, and the diesel is fed into the isolinear fluidized bed reactor from the lower part of the reaction section;

[0116] Preferably, at least part of one or more of the C4 olefins, the light gasoline fraction, the heavy aromatic fraction and the slurry oil is fed into the isolinear fluidized bed reactor through the reaction section for recycling;

[0117] The feed positions of the C4 olefins, the light gasoline fraction and the heavy aromatic fraction are located below the feed position of the diesel, or are fed through the feed position of the diesel; the feed position of the oil slurry is located above the feed position of the diesel.

[0118] It should be noted that, compared with fixed bed and moving bed reactors, isolinear fluidized bed reactors do not require external heating and can be produced continuously; compared with conventional riser reactors, the oil agent is more fully contacted and is more suitable for catalytic cracking of light hydrocarbons such as diesel with volume expansion. The inventors of this application have innovatively discovered in the process of many years of research and development that feeding diesel at the lower part of the reaction section is conducive to better conversion of diesel into ethylene, propylene, etc. In addition, by feeding C4 olefins, light gasoline fractions and heavy aromatic fractions according to the above positions for recycling, the yield of ethylene, propylene, etc. can be further improved. By feeding the slurry oil according to the above positions for recycling, the heat can be better utilized and the thermal balance of the reactor can be maintained, so that the reaction can proceed better.

[0119] According to a second specific implementation of the method described in the first aspect of the present invention, the feedstock oil includes diesel and heavy oil, the diesel is fed into the isolinear fluidized bed reactor from the lower part of the reaction section, and the heavy oil is fed into the isolinear fluidized bed reactor from the middle part of the reaction section;

[0120] Preferably, at least part of one or more of the C4 olefins, the light gasoline fraction, the heavy aromatic fraction and the slurry oil is fed into the isolinear fluidized bed reactor through the reaction section for recycling;

[0121] The feed positions of the C4 olefins, the light gasoline fraction and the heavy aromatic fraction are located below the feed position of the diesel, or are fed through the feed position of the diesel; and the oil slurry is fed through the feed position of the heavy oil.

[0122] It should be noted that in this embodiment, diesel and heavy oil are catalytically cracked in the same reactor. The inventors of the present application have innovatively discovered in the long-term research and development process that the diesel and heavy oil are fed at the above positions respectively, which can increase the proportion of high-value products such as ethylene and propylene in the final chemical materials, that is, the yield of high-value products such as ethylene and propylene can be increased. By feeding C4 olefins, light gasoline fractions and heavy aromatic fractions at the above positions for recycling, the yield of high-value products such as ethylene and propylene can be further increased. By feeding slurry at the above positions for recycling, the heat can be better utilized, the reactor can be better kept in thermal balance, and the reaction can be better carried out.

[0123] According to a third specific implementation of the method of the first aspect of the present invention, the feedstock oil is diesel, and the diesel is fed into the isolinear fluidized bed reactor from the lower part of the reaction section;

[0124] Furthermore, step (1) further comprises:

[0125] The heavy oil is contacted and reacted with a shape-selective molecular sieve catalyst in a riser reactor;

[0126] In step (2), a portion of the oil mixture is derived from the contact reaction between the diesel and the shape-selective molecular sieve catalyst, and another portion is derived from the contact reaction between the heavy oil and the shape-selective molecular sieve catalyst; in step (4), a portion of the regenerated catalyst is returned to the isolinear fluidized bed reactor for recycling, and another portion of the regenerated catalyst is returned to the riser reactor for recycling;

[0127] Preferably, at least part of one or more of the C4 olefins, the light gasoline fraction, the heavy aromatic fraction and the slurry oil is fed into the riser reactor for recycling;

[0128] The feed positions of the C4 olefins, the light gasoline fraction and the heavy aromatic fraction are located below the feed position of the heavy oil, and the slurry oil is fed through the feed position of the heavy oil.

[0129] It should be noted that in this embodiment, diesel and heavy oil are catalytically cracked in different reactors, and this embodiment is a catalytic cracking process method in which an isolinear fluidized bed reactor is coupled with a riser reactor. The oil-agent mixture after the diesel reaction and the oil-agent mixture after the heavy oil reaction can be separated from the oil-agent separately, or can be separated from the oil-agent together. In this embodiment, during refining, C4 olefins, light gasoline fractions, heavy aromatic fractions and oil slurry are fed and refined according to the above positions, which can make the reactions in the two reactors proceed better, improve the yields of ethylene and propylene, and obtain more high-value products.

[0130] According to a specific embodiment of the method according to the first aspect of the present invention, the diesel is selected from a combination of one or more of straight-run diesel, catalytic cracking diesel and hydrogenated diesel; and / or,

[0131] The boiling point of the diesel is 180-380°C and the density is less than or equal to 850kg / m 3 .

[0132] It should be noted that the method of the present invention has a wide range of applicability. In addition to the above-mentioned diesel, it can also be applied to a variety of other light hydrocarbon feedstock oils.

[0133] According to a specific implementation of the method described in the first aspect of the present invention, the heavy oil is wax oil and / or residual oil.

[0134] It should be noted that the method of the present invention has a wide range of applicability, and can be applied to a variety of other heavy oils in addition to the above-mentioned heavy oils.

[0135] According to a specific embodiment of the method of the first aspect of the present invention, the conditions for the contact reaction between the diesel and the shape-selective molecular sieve catalyst in step (1) include:

[0136] The reaction temperature is 620-720° C., the reaction pressure is 0.2-0.5 MPa, the reaction time is 3.0-7.0 seconds, and the weight ratio of the shape-selective molecular sieve catalyst to the diesel is (6-10):1;

[0137] The diesel is fed into the isolinear fluidized bed reactor under fluidization of a fluidizing medium;

[0138] The fluidizing medium is atomized water, and the mass ratio of the atomized water to the diesel is (0.20-0.30):1;

[0139] The oil and gas linear velocity in the reaction zone is 1.0-2.0 m / s;

[0140] and / or,

[0141] The method further comprises the following steps before step (1):

[0142] Preheating the feedstock oil to a preheating temperature of 200 to 400° C., preferably 260 to 360° C.;

[0143] The preheating is carried out by heating in a heating furnace, or by exchanging heat between the crude oil and the chemical material obtained from step (3).

[0144] It should be noted that the method of the present invention is to contact diesel with a high-activity catalyst in a variable diameter constant-speed fluidized bed reactor to carry out a high-temperature, high-dose-to-oil ratio catalytic cracking reaction, which can convert diesel into gasoline and liquefied gas, achieve a higher conversion rate at a higher reaction temperature, and achieve efficient continuous production. In the method of the present invention, by controlling the reaction conditions as above, the yield of ethylene, propylene, etc. can be further improved.

[0145] According to a specific embodiment of the method of the first aspect of the present invention, the conditions for the contact reaction between the heavy oil and the shape-selective molecular sieve catalyst in the riser reactor include:

[0146] The reaction temperature is 620-720° C., the reaction pressure is 0.2-0.5 MPa, the weight ratio of the shape-selective molecular sieve catalyst to the heavy oil is (6-10):1, and the reaction time is 3.0-7.0 seconds;

[0147] The heavy oil is fed into the riser reactor under fluidization of a fluidizing medium;

[0148] The fluidizing medium is atomized water, and the mass ratio of the atomized water to the heavy oil is (0.20-0.30):1;

[0149] The oil and gas linear velocity in the riser reactor is 2.0-12.0 m / s.

[0150] It should be noted that in this embodiment, by controlling the reaction conditions of the heavy oil as described above, the reaction in the riser reactor can be better performed, so that more heavy oil can be converted into high-value products such as ethylene and propylene.

[0151] According to a specific embodiment of the method described in the first aspect of the present invention, in step (3), the oil-gas separation system is selected from a combination of one or more of two distillation towers with a theoretical plate number higher than 20, an absorption stabilization system, and a gas separation system;

[0152] Propylene, H2 and C1-C4 alkanes, a BTX fraction and a methyl naphthalene oil fraction are also obtained through the separation described in step (3).

[0153] It should be noted that the oil-gas separation system is a high-precision separation system, which can accurately separate ethylene, propylene, H2 and C1-C4 alkanes, C4 olefins, light gasoline fractions, BTX fractions, heavy aromatic fractions, methyl naphthalene oil fractions and oil slurry, etc. BTX fraction refers to a mixture of benzene, toluene and xylene, referred to as light aromatics.

[0154] Specifically, the oil and gas are precisely separated by the high-precision separation system, and the gas product separation obtains ethylene, propylene, C4 olefins, H2 and C1-C4 alkanes, and the liquid product separation obtains light gasoline fraction with an initial boiling point of -60°C, BTX fraction with a boiling point of 60-150°C, heavy aromatic fraction with a boiling point of 150-240°C, methyl naphthalene oil fraction with a boiling point of 240-340°C, and slurry oil with a boiling point of >340°C. The BTX fraction is hydrogenated and extracted to obtain BTX and light aromatic raffinate oil; it can better meet the demand for catalytic cracking of light hydrocarbons to produce more chemical materials, and is different from the conventional catalytic cracking separation system, which cuts the liquid product into gasoline fraction (initial boiling point -200°C), diesel fraction (200-360°C), and slurry oil fraction (>360°C). Preferably, the C4 olefins, light gasoline fraction, light aromatic raffinate oil, heavy aromatic fraction, and slurry oil obtained by high-precision separation can be returned to the reactor for refining. Ethylene and BTX can be better produced by recycling light gasoline fractions, light aromatic raffinate oil and heavy aromatic fractions, and the heat required by the reactor can be further supplemented by recycling slurry oil.

[0155] According to a specific implementation of the method according to the first aspect of the present invention, in step (4):

[0156] The regeneration temperature of the regenerator is 640-780°C and the pressure is 0.3-0.6MPa;

[0157] The circulation rate of the regenerated catalyst is 150-200 kg / (m 2 ·Second);

[0158] The regeneration atmosphere in the regenerator is selected from one of air, oxygen-enriched and pure oxygen;

[0159] The flue gas is optionally returned to the regenerator for recycling after heat exchange, and the temperature of the flue gas returned to the regenerator for recycling is 340-580°C.

[0160] It should be noted that in the method of the present invention, the regeneration atmosphere is preferably an oxygen-enriched and / or pure oxygen atmosphere. Compared with conventional air regeneration, less heat is required to heat up the regeneration gas, the charring intensity is high, the regeneration temperature is also high, and a relatively high regeneration agent temperature can be maintained. The high-temperature flue gas after regeneration can be partially or completely circulated back to the regenerator, and the oxygen-containing high-temperature flue gas can be partially or completely returned to the regenerator for recycling under the above conditions without heat exchange or after partial heat exchange, which can make full use of the oxygen in the flue gas and maintain a relatively high regeneration temperature and a relatively high regeneration agent temperature of the regenerator, and solve the problem of flue gas carrying heat out of the regeneration system, and reduce the emission of waste gases such as carbon dioxide, thereby greatly saving energy and reducing emissions.

[0161] In a second aspect, the present invention relates to a system for producing chemical materials including ethylene based on an isolinear fluidized bed reactor, such as Figure 1 As shown, the system includes a constant linear velocity fluidized bed reactor 1, a cyclone separator IV-1, a settler IV, an oil-gas separation system 6 and a regenerator 20;

[0162] The isolinear fluidized bed reactor 1 is provided with a reactor pre-lifting section I, a reactor reaction section II, a reactor outlet section III and a catalyst stripping section IV-2; the catalyst in the isolinear fluidized bed reactor 1 is in an upward flow; the cyclone separator IV-1 and the settler IV are located above the catalyst stripping section IV-2; the inner diameter of the reactor outlet section III is smaller than that of the reactor reaction section II;

[0163] The outlet of the pre-lifting section I of the reactor is connected to the inlet of the reaction section II of the reactor, and the outlet of the reaction section II of the reactor is connected to the inlet of the outlet section III of the reactor;

[0164] The reactor reaction section II is a variable diameter reaction section, and the inner diameter of the reactor reaction section II gradually decreases from top to bottom; a light hydrocarbon feedstock oil inlet 2 and a first atomizing steam inlet 3 are provided at the lower part of the reactor reaction section II, and the light hydrocarbon feedstock oil inlet 2 and the first atomizing steam inlet 3 are connected;

[0165] The oil agent outlet of the reactor outlet section III is connected to the oil agent inlet of the cyclone separator IV-1, the catalyst outlet of the cyclone separator IV-1 is connected to the inlet of the settler IV, and the oil and gas outlet of the cyclone separator IV-1 is connected to the oil and gas inlet of the oil and gas separation system 6;

[0166] The outlet of the settler IV is connected to the inlet of the catalyst stripping section IV-2, the catalyst outlet of the catalyst stripping section IV-2 is connected to the inlet of the regenerator 20 to be regenerated catalyst, and the oil and gas outlet of the catalyst stripping section IV-2 is connected to the oil and gas separation system 6;

[0167] The regenerator 20 is provided with an oxygen-containing regeneration gas inlet 21 and a flue gas outlet 23, the flue gas outlet 23 is connected to the oxygen-containing regeneration gas inlet 21 through a flue gas circulation system 24, the regeneration catalyst outlet of the regenerator 20 is connected to the catalyst inlet of the reactor pre-lift section I through a first regeneration agent delivery pipeline 22, and the bottom of the reactor pre-lift section I is provided with a first fluidizing medium inlet 4;

[0168] The oil-gas separation system 6 is provided with an ethylene outlet 7, a propylene outlet 8, an H2 and C1-C4 alkane outlet 9, a C4 olefin outlet 10, a light gasoline fraction outlet 11, a BTX fraction outlet 12, a heavy aromatic fraction outlet 13, a methyl naphthalene oil fraction outlet 14 and an oil slurry outlet 15;

[0169] Preferably, the oil and gas outlet of the cyclone separator IV-1 is connected to the oil and gas inlet of the oil and gas separation system 6 through the reaction oil and gas pipeline 5, and the oil and gas outlet of the catalyst stripping section IV-2 is connected to the oil and gas inlet of the oil and gas separation system 6 through the reaction oil and gas pipeline 5;

[0170] Preferably, a stripping medium inlet 18 is provided at the lower portion of the catalyst stripping section IV-2;

[0171] Preferably, the catalyst outlet of the catalyst stripping section IV-2 is connected to the catalyst inlet to be regenerated of the regenerator 20 through a regenerated catalyst delivery pipeline 19;

[0172] Preferably, a first heavy feedstock oil inlet 16 and a second atomizing steam inlet 17 are provided in the middle of the reaction section II of the reactor, and the first heavy feedstock oil inlet 16 is connected to the second atomizing steam inlet 17;

[0173] Preferably, the reactor reaction section II is provided with a first recycling inlet and a second recycling inlet, wherein the first recycling inlet and the second recycling inlet are respectively located below and above the light hydrocarbon feedstock inlet 2;

[0174] The C4 olefin outlet 10, the light gasoline fraction outlet 11 and the heavy aromatic fraction outlet 13 are respectively connected to the first recycling inlet, or are respectively connected to the light hydrocarbon feedstock oil inlet 2; the slurry oil outlet 15 is connected to the second recycling inlet, or is connected to the first heavy feedstock oil inlet 16.

[0175] It should be noted that, in the system of the present invention, the isolinear fluidized bed reactor 1 and the regenerator 20 can be arranged in parallel or overlappingly, and the isolinear fluidized bed reactor 1 and the settler IV can be built-in or external; the catalyst is lifted by media such as air and / or water vapor so that it circulates between the reactor and the regenerator.

[0176] The constant linear velocity fluidized bed reactor described in the present invention refers to a fluidized bed reactor in which the oil and gas in the catalytic cracking reaction maintain a relatively uniform linear velocity. Compared with an ordinary fluidized bed with a uniform diameter, the oil and gas in the constant linear velocity fluidized bed reactor contact the catalyst in a plug flow state at a uniform linear velocity, the catalyst density is high, and the oil and gas contact is more complete.

[0177] It should be noted that light hydrocarbon feedstock oil such as diesel can be fed to the lower part of the reactor reaction section II through the light hydrocarbon feedstock oil inlet 2 and under the atomization of the atomizing steam entering the first atomizing steam inlet 3. The oil-agent mixture after the reaction flows into the cyclone separator IV-1 through the reactor outlet section III for cyclone separation to obtain the first reaction oil gas and the residual oil gas to be regenerated catalyst; the first reaction oil gas flows into the oil-gas separation system 6 through the reaction oil-gas pipeline 5 for separation, and the residual oil gas to be regenerated catalyst flows into the settler IV for sedimentation, and the residual oil gas to be regenerated catalyst after sedimentation enters the catalyst stripping section IV-2 for stripping to obtain the second reaction oil gas and the catalyst to be regenerated; the obtained second reaction oil gas enters the oil-gas separation system 6 through the reaction oil-gas pipeline 5 for separation, the obtained catalyst to be regenerated enters the regenerator 20 through the regenerator delivery pipeline 19 for regeneration, and the obtained regenerated catalyst enters the reactor pre-lifting section I through the first regenerator delivery pipeline 22, and the regenerated flue gas can be partially or completely returned to the regenerator 20 for recycling after heat exchange or without heat exchange.

[0178] The heavy oil can enter the middle part of the reactor reaction section II through the first heavy crude oil inlet 16 and under the atomization of the atomizing steam entering from the second atomizing steam inlet 17, and contact with the catalyst to react. The oil mixture after the reaction enters the cyclone separator IV-1 for cyclone separation, and then the catalyst is sequentially settled, stripped, the catalyst to be regenerated, and the oil and gas are separated.

[0179] The system of the present invention is based on a constant linear velocity fluidized bed reactor for catalytic reaction of diesel or diesel and heavy oil. In particular, by setting the positions of the feed ports of diesel and heavy oil and the feed position of recycled oil as above, diesel and heavy oil can react better, and the yield of high-value products such as ethylene and propylene can be significantly improved.

[0180] According to a specific implementation of the system described in the second aspect of the present invention, Figure 2 As shown, the system is further provided with a riser reactor 25, and the riser reactor 25 is provided with a second heavy feedstock oil inlet 28 and a third atomizing steam inlet 29, and the second heavy feedstock oil inlet 28 is connected to the third atomizing steam inlet 29;

[0181] The regenerated catalyst outlet of the regenerator 20 is connected to the catalyst inlet at the bottom of the riser reactor 25 through a second regeneration agent delivery pipeline 27. The bottom of the riser reactor 25 is also provided with a second fluidizing medium inlet 26.

[0182] The oil agent outlet of the riser reactor 25 is connected to the oil agent inlet of the cyclone separator IV-1;

[0183] Preferably, the riser reactor 25 is provided with a third recycle port, which is located below the second heavy feedstock oil inlet 28, the C4 olefin outlet 10, the light gasoline fraction outlet 11 and the heavy aromatic fraction outlet 13 are respectively connected to the third recycle port, and the slurry oil outlet 15 is connected to the second heavy feedstock oil inlet 28.

[0184] It should be noted that, in this embodiment, light hydrocarbon feedstock oil such as diesel is reacted in the isolinear fluidized bed reactor 1, and heavy oil is reacted in the riser reactor 25. The heavy oil can enter the riser reactor 25 through the second heavy feedstock oil inlet 28, and the regenerated catalyst enters the bottom of the riser reactor 25 through the second regeneration agent delivery pipeline 27. The heavy oil contacts the catalyst for catalytic reaction, and the resulting oil-agent mixture enters the cyclone separator IV-1 for oil-agent separation, and then sedimentation, stripping, and oil-gas separation are performed. By allowing the two feedstock oils to undergo catalytic reactions in the above-mentioned two reactors respectively, especially controlling the positions of the feedstock oil and the recycled oil after feeding as described above, the reaction can be better carried out, and more high-value products such as ethylene and propylene can be prepared.

[0185] It should be noted that the system described in the second aspect of the present invention can carry out catalytic cracking of crude oil to produce chemical materials including ethylene based on the method described in the first aspect of the present invention, and the method of the first aspect of the present invention can be implemented based on the system described in the second aspect.

[0186] A specific implementation of the present disclosure is as follows: Figure 1 As shown, in this embodiment, an upward variable diameter constant linear velocity fluidized bed reactor 1 is used, and light hydrocarbon feedstock oil enters the reactor through a light hydrocarbon feedstock oil inlet 2 by downward feeding to contact the regeneration agent for catalytic cracking reaction, and the spent agent after the reaction is separated from the oil and gas and then regenerated, and the regenerated flue gas is partially circulated back to the regenerator. The process flow is as follows:

[0187] The light hydrocarbon feedstock oil enters the bottom or lower part of the reactor reaction section II in the isolinear fluidized bed reactor 1 through the light hydrocarbon feedstock oil inlet 2 by being atomized by the atomizing steam flowing in through the first atomizing steam inlet 3, and the hot regenerated agent is introduced into the reactor pre-lifting section I of the isolinear fluidized bed reactor through the first regenerated agent delivery pipeline 22, and ascends into the reactor reaction section II under the fluidization of the fluidized medium entering through the first fluidized medium inlet 4, and the light hydrocarbon feedstock oil contacts the hot regenerated agent to undergo catalytic cracking reaction.

[0188] The oil-agent mixture formed by the reaction of oil gas and catalyst enters the cyclone separator IV-1 through the reactor outlet section III for oil-agent separation. The separated catalyst is settled to the catalyst stripping section IV-2 through the settler IV. The stripping medium entering through the stripping medium inlet 18 is stripped and then enters the regenerator 20 through the spent catalyst delivery pipeline 19.

[0189] The regenerated catalyst is regenerated in an oxygen-containing atmosphere in the regenerator. The oxygen-containing regeneration gas entering the oxygen-containing regeneration gas inlet 21 includes air, oxygen, etc. The regeneration temperature is 640-780°C. The regenerated catalyst is recycled. The regenerated flue gas flows out through the flue gas outlet 23 and can be partially circulated back to the regenerator through the flue gas circulation system 24.

[0190] The separated reaction oil and gas enter the oil and gas separation system 6 through the reaction oil and gas pipeline 5, and are separated to obtain ethylene flowing out of the ethylene outlet 7, propylene flowing out of the propylene outlet 8, H2 and C1-C4 alkanes flowing out of the H2 and C1-C4 alkane outlet 9, C4 olefins flowing out of the C4 olefin outlet 10, light gasoline fraction flowing out of the light gasoline fraction outlet 11, BTX fraction flowing out of the BTX fraction outlet 12, heavy aromatic fraction flowing out of the heavy aromatic fraction outlet 13, methyl naphthalene oil fraction flowing out of the methyl naphthalene oil fraction outlet 14, and slurry oil flowing out of the slurry oil outlet 15.

[0191] C4 olefins, light gasoline fractions, heavy aromatic fractions, and slurry oil can be recycled and / or not recycled according to production needs. In order to produce more chemical materials, C4 olefins, light gasoline and heavy aromatic fractions are preferably recycled. After being mixed with light crude oil, they can enter the isolinear fluidized bed reactor 1 through the light hydrocarbon crude oil inlet 2, and further preferably enter the bottom of the reactor reaction section II, that is, feed at the bottom of the light hydrocarbon crude oil nozzle. In order to meet the needs of the device's self-heating balance, slurry oil recycling is preferred, that is, slurry oil and / or heavy crude oil are atomized by atomizing steam and enter the reactor, preferably entering the middle of the reactor reaction section II, that is, feeding at the top of the light hydrocarbon crude oil nozzle.

[0192] Figure 2This is a process flow diagram of another embodiment of the present disclosure. The light hydrocarbon feedstock uses a variable diameter constant linear velocity fluidized bed reactor 1 as in the above embodiment. The difference is that the oil slurry is recycled and / or the heavy feedstock enters a conventional riser reactor 25. The two reactors can each use a separate settler or share a settler. In this embodiment, the two reactors use a single settler. The process flow is as follows:

[0193] The light hydrocarbon feedstock oil fed into the light hydrocarbon feedstock oil inlet 2 is atomized by the atomizing steam entering the first atomizing steam inlet 3 and enters the bottom of the reactor reaction section II in the constant linear velocity fluidized bed reactor 1. The hot regeneration agent is introduced into the reactor pre-lifting section I of the constant linear velocity fluidized bed reactor through the first regeneration agent delivery pipeline 22, and enters the reactor reaction section II upward under the fluidization of the fluidizing medium entering the first fluidizing medium inlet 4, and the light hydrocarbon feedstock oil contacts the hot regeneration agent to perform catalytic cracking reaction.

[0194] The heavy crude oil enters the lower part of the riser reactor 25 through the second heavy crude oil inlet 28 after being atomized by the atomizing steam entering the third atomizing steam inlet 29, while the hot regeneration agent is introduced into the bottom of the riser reactor through the second regeneration agent delivery pipeline 27, and ascends under the fluidization of the fluidizing medium entering the second fluidizing medium inlet 26, and the heavy crude oil contacts the hot regeneration agent to perform catalytic cracking reaction.

[0195] The oil-agent mixture after the reaction of light hydrocarbon feedstock oil and heavy feedstock oil enters the cyclone separator IV-1 for oil-agent separation; the oil-agent mixture formed by the reaction of oil gas and catalyst enters the cyclone separator IV-1 through the reactor outlet section III for oil-agent separation, and the separated catalyst is settled to the catalyst stripping section IV-2 through the settler IV, and the stripping medium entering through the stripping medium inlet 18 is stripped and enters the regenerator 20 through the spent catalyst conveying pipeline 19.

[0196] The regenerated catalyst is regenerated in an oxygen-containing atmosphere in the regenerator. The oxygen-containing regeneration gas entering the oxygen-containing regeneration gas inlet 21 includes air, oxygen, etc. The regeneration temperature is 640-780°C. The regenerated catalyst is recycled; the regenerated flue gas part is circulated back to the regenerator through the flue gas circulation system 24.

[0197] The separated reaction oil and gas enter the oil and gas separation system 6 through the reaction oil and gas pipeline 5, and are separated to obtain ethylene flowing out of the ethylene outlet 7, propylene flowing out of the propylene outlet 8, H2 and C1-C4 alkanes flowing out of the H2 and C1-C4 alkane outlet 9, C4 olefins flowing out of the C4 olefin outlet 10, light gasoline fraction flowing out of the light gasoline fraction outlet 11, BTX fraction flowing out of the BTX fraction outlet 12, heavy aromatic fraction flowing out of the heavy aromatic fraction outlet 13, methyl naphthalene oil fraction flowing out of the methyl naphthalene oil fraction outlet 14, and slurry oil flowing out of the slurry oil outlet 15.

[0198] C4 olefins, light gasoline fractions, heavy aromatic fractions and slurry oil can be recycled and / or not recycled according to production needs. For slurry oil recycling, it is preferred that the heavy crude oil enters the riser reactor 25 after being atomized by the atomizing steam entering through the second heavy crude oil inlet 28 and the third atomizing steam inlet 29. In order to meet the demand for more chemical materials, C4 olefins, light gasoline and heavy aromatic fractions are preferentially recycled, and their recycling can be preferentially selected to enter the bottom of the riser reactor 25, that is, to feed the lower part of the second heavy crude oil inlet 28 for catalytic cracking reaction.

[0199] The present invention is further described in detail below by way of examples, but the present invention is not limited thereto. The raw materials used in the examples can all be obtained through commercial routes.

[0200] The light hydrocarbon feedstock used in the embodiment is hydrogenated diesel A obtained by hydrofining straight-run diesel from a refinery, and the heavy feedstock oil is cracked tail oil B obtained by hydrocracking wax oil from a refinery. The properties of the two are shown in Table 1.

[0201] Table 1

[0202]

[0203]

[0204] The catalysts used in the examples are the same, and their preparation methods are briefly described as follows:

[0205] 1) Use 150kg of decationized water to slurry 22.6kg of halloysite (industrial product of Suzhou Clay Company, solid content 71.6m%), then add 16.4kg of pseudo-boehmite (industrial product of Shandong Aluminum Plant, solid content 63m%), adjust the pH to 2-4 with hydrochloric acid, stir evenly, stand and age at 60-70°C for 1 hour, keep the pH at 2-4, reduce the temperature to below 60°C, add 12.5Kg of aluminum sol (product of Sinopec Catalyst Qilu Branch, Al2O3 content is 21.7m%), stir for 40 minutes, and obtain a mixed slurry.

[0206] 2) Add the medium-pore ZRP-5 molecular sieve with MFI structure (industrial product of Sinopec Catalyst Qilu Branch, SiO2 / Al2O3=39, phosphorus content P2O5=4.6% by weight, iron content Fe2O3=0.5% by weight, dry basis 35.8kg) to the mixed slurry obtained in step 2), stir evenly, put it in a bonding machine after mixing, add appropriate amount of water, stir well, place it in the air for 4 hours, and spray dry it into shape.

[0207] 3) The catalyst obtained by spray drying in step 2) was dried in a drying oven at 120°C for 3 hours, and then washed with diammonium phosphate solution (phosphorus content of 1m%) to remove free Na+ , washing to remove free Na + , and dried again to obtain a catalyst named CAT-4.

[0208] The catalyst comprises 55.1 wt% phosphorus / iron modified shape selective molecular sieve ZRP-5, 15.9 wt% pseudo-boehmite, 4.2 wt% aluminum sol and 24.8 wt% kaolin. Its properties are listed in Table 2.

[0209] Table 2

[0210]

[0211]

[0212] Example 1

[0213] This embodiment follows Figure 1 The process was tested, using hydrogenated straight-run diesel A in Table 1 as raw material, and the test was carried out on an isolinear fluidized bed reactor using a CAT-4 catalyst. After being preheated at 360°C, the hydrogenated straight-run diesel A enters the bottom of the reaction section of the isolinear fluidized bed reactor. At a reaction pressure of 0.35MPa, water vapor is used as the fluidizing medium, and the mass ratio of atomized steam to crude oil is 0.30. As the fluidizing medium flows from bottom to top, a catalytic cracking reaction is carried out at a reaction temperature (based on the reactor outlet, the same below) of 680°C, a weight ratio of catalyst to crude oil of 9.0, and a reaction time of 5.0 seconds; after the reaction, the oil agent is separated, and the separated reaction oil and gas are separated by an oil and gas separation system to obtain the product H2, ethylene, Propylene, C1-C4 alkanes, BTX, methyl naphthalene oil and C4 olefins, light gasoline fractions, heavy aromatic fractions and slurry oil, C4 olefins, light gasoline fractions, heavy aromatic fractions and slurry oil are recycled; the spent catalyst after oil separation is stripped by steam to remove the oil and gas adsorbed inside, and then sent to the regenerator, using oxygen as the regeneration gas, and regenerating it at a regeneration temperature of 680-730℃; the regenerated regenerated agent is recycled, 40% of the flue gas after regeneration is recycled, the circulating flue gas temperature is 500℃, and the regeneration dense phase temperature is maintained at 730℃. The operating conditions and product distribution are listed in Table 3.

[0214] As can be seen from Table 3, in Example 1, the hydrogenated straight-run diesel was subjected to catalytic cracking reaction in a constant linear velocity fluidized bed reactor, with an ethylene yield of 17.26% by weight, a propylene yield of 18.40% by weight, a light aromatics (BTX: benzene + toluene + xylene) yield of 14.51% by weight, and a coke yield of 12.70% by weight.

[0215] Comparative Example 1

[0216] The catalytic cracking reaction was carried out by using the same feedstock oil, catalyst and process conditions as in Example 1, except that: 1) the riser reactor was used in Example 1; 2) air was used as the regeneration gas, and the flue gas was not circulated; 3) in order to maintain the same process conditions as in Example 1, it was necessary to spray combustion oil in the regenerator to provide heat. The operating conditions and product distribution are listed in Table 3.

[0217] As can be seen from Table 3, compared with Comparative Example 1 (riser reactor), Example 1 (constant linear velocity fluidized bed reactor) has an ethylene yield increased by 1.40 percentage points, a propylene yield increased by 1.61 percentage points, a light aromatics (BTX: benzene + toluene + xylene) yield increased by 1.15 percentage points, and a coke yield decreased by 1.81 percentage points.

[0218] Example 2

[0219] This embodiment follows Figure 2 The process was tested, using 70% hydrogenated straight-run diesel A and 30% cracked tail oil B in Table 1 as raw materials. The two were tested on an isolinear fluidized bed reactor and a riser reactor, respectively, using a CAT-4 catalyst. The hydrogenated straight-run diesel A was preheated at 260°C and entered the bottom of the reaction section of the isolinear fluidized bed reactor, and the cracked tail oil B was preheated at 260°C and entered the bottom of the conventional riser reactor; both were at a reaction pressure of 0.30MPa, with water vapor as the fluidizing medium, and a mass ratio of atomized steam to crude oil of 0.20. As the fluidized medium flows from bottom to top in different reactors, catalytic cracking reactions are carried out under the conditions of a reaction temperature (based on the reactor outlet) of 640°C, a weight ratio of catalyst to crude oil of 7.5, and a reaction time of 6.5 seconds; the oil and gas and catalyst after the reaction of the cracked tail oil B in the riser reactor are merged into the isolinear fluidized bed reactor, and the oil agent is separated together with the oil agent after the reaction of the hydrogenated straight-run diesel A. ; The reaction oil and gas after oil separation are separated by oil and gas separation system to obtain products H2, ethylene, propylene, C1-C4 alkanes, BTX, methyl naphthalene oil and C4 olefins, light gasoline fraction, heavy aromatic fraction and oil slurry, C4 olefins, light gasoline fraction, heavy aromatic fraction and oil slurry are recycled; the catalyst to be regenerated after oil separation is stripped by steam to remove the oil and gas adsorbed inside it and then sent to the regenerator, using 20% ​​oxygen and 80% air enriched air as regeneration gas, and regenerating at a regeneration temperature of 680-710℃ with the catalyst to be regenerated; the regenerated regenerated agent is recycled, and the flue gas after regeneration is partially recycled, the circulating flue gas temperature is 400℃, and the regeneration dense phase temperature is maintained at 710℃. The operating conditions and product distribution are listed in Table 3.

[0220] As can be seen from Table 3, in Example 2, the hydrogenated straight-run diesel was subjected to catalytic cracking reactions in a constant linear velocity fluidized bed reactor and the cracked tail oil was subjected to catalytic cracking reactions in a riser reactor at the same time, and the ethylene yield was 16.45 wt%, the propylene yield was 19.83 wt%, the light aromatics (BTX: benzene + toluene + xylene) yield was 16.61 wt%, and the coke yield was 7.49 wt%.

[0221] Comparative Example 2

[0222] The catalytic cracking reaction was carried out by using the same feedstock oil, catalyst and process conditions as in Example 2, except that: 1) both hydrogenated straight-run diesel A and cracked tail oil B in Comparative Example 2 used riser reactors; 2) air was used as the regeneration gas, and the flue gas was not circulated; 3) in order to maintain the same process conditions as in Example 2 for the reverse regeneration system operation, it was necessary to spray combustion oil in the regenerator to provide heat. The operating conditions and product distribution are listed in Table 3.

[0223] As can be seen from Table 3, compared with Comparative Example 2 (riser reactor), Example 2 (constant linear velocity fluidized bed reactor + riser reactor) has an ethylene yield increased by 1.72 percentage points, a propylene yield increased by 0.85 percentage points, a light aromatics (BTX: benzene + toluene + xylene) yield increased by 0.36 percentage points, and a coke yield decreased by 1.69 percentage points.

[0224] Table 3

[0225]

[0226]

[0227] The inventors of the present application have found through years of research that: (1) Diesel catalytic cracking is different from heavy oil catalytic cracking, and small molecules are difficult to crack, thus requiring a higher reaction severity; (2) The isolinear fluidized bed reactor is adapted to the volume expansion reaction system and reduces the dry gas and coke yields under the high reaction severity of diesel; (3) Diesel catalytic cracking produces low coke, and it is difficult to maintain the heat required for its own reaction through self-heating balance using conventional heavy oil regeneration technology; (4) The traditional catalytic cracking oil-gas separation system oil product cutting according to gasoline fraction (initial distillation point -200°C), diesel fraction (200-360°C), and oil slurry fraction (>360°C) cannot meet the demand for catalytic cracking of light hydrocarbons to produce more chemical materials. The present application not only solves the problem of heat balance of light hydrocarbon catalytic cracking itself, but also achieves a higher conversion rate of catalytic cracking of light hydrocarbons at a higher reaction temperature by using an isolinear fluidized bed reactor and oxygen-enriched and / or pure oxygen regeneration, and partially and / or completely returning the high-temperature flue gas after regeneration to the regenerator, so as to better convert raw oils such as diesel into high-value products such as ethylene and propylene.

[0228] In the description of the present application, it should be noted that the terms "upper", "lower", "inside", "outside", "front", "back", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships in the working state of the present application. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the present application.

[0229] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "install", "connect" and "connect" should be understood in a broad sense. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0230] The present application has been described above in conjunction with preferred embodiments, but these embodiments are only exemplary and serve only as an illustration. On this basis, various replacements and improvements may be made to the present application, all of which fall within the scope of protection of the present application.

Claims

1. A method for producing chemical materials including ethylene based on an isolinear fluidized bed reactor, characterized in that: The method comprises the following steps: (1) contacting and reacting the crude oil with a shape-selective molecular sieve catalyst in a constant linear velocity fluidized bed reactor to obtain an oil-agent mixture; The shape-selective molecular sieve catalyst comprises a shape-selective molecular sieve, and the shape-selective molecular sieve is selected from a molecular sieve with a ten-membered ring structure; the catalyst in the isolinear fluidized bed reactor flows upward, and the inner diameter of the reaction section decreases from top to bottom; (2) separating the oil mixture to obtain reaction oil gas and a catalyst to be produced; The oil mixture is subjected to cyclone separation and sedimentation to obtain a first reaction oil gas and a catalyst to be regenerated with residual oil gas; the catalyst to be regenerated with residual oil gas is subjected to stripping to obtain a second reaction oil gas and the catalyst to be regenerated; the reaction oil gas includes the first reaction oil gas and the second reaction oil gas; (3) separating the reaction oil and gas in an oil and gas separation system to obtain chemical materials including ethylene, C4 olefins, light gasoline fraction, heavy aromatic fraction and slurry oil; (4) allowing the catalyst to be regenerated to enter a regenerator for regeneration in an oxygen-containing atmosphere to obtain a regenerated catalyst and flue gas; returning at least a portion of the regenerated catalyst to the isolinear fluidized bed reactor for recycling, and returning at least a portion of the flue gas to the regenerator for recycling.

2. The method according to claim 1, characterized in that In step (1): The ten-membered ring structure molecular sieve is selected from a combination of one or more of ZSM-5 molecular sieve, ZSM-11 molecular sieve, ZSM-12 molecular sieve, ZSM-23 molecular sieve, ZSM-35 molecular sieve, ZSM-38 molecular sieve, ZSM-48 molecular sieve and ZRP-5 molecular sieve, and the average pore size of the ten-membered ring structure molecular sieve is 0.5-0.6 nm; and / or, The shape-selective molecular sieve catalyst further comprises an oxide and optional clay, wherein the oxide is selected from a combination of one or more of aluminum oxide, silicon oxide and modified oxide; the modified oxide is selected from one or more metal element oxides and / or non-metal element oxides in Group IA, Group IIA, Group VA, Group IIIB and Group VIII; The ten-membered ring structure molecular sieve is a molecular sieve obtained by modifying a mesoporous molecular sieve with the modified oxide; The mass proportion of the ten-membered ring structure molecular sieve in the shape-selective molecular sieve catalyst is 40-70%, and the mass proportion of the modified oxide in the shape-selective molecular sieve catalyst is 1.0-10.0%; and / or, The average particle size of the shape-selective molecular sieve catalyst is 40 to 150 microns.

3. The method according to claim 1, characterized in that The raw oil is diesel, and the diesel is fed into the isolinear fluidized bed reactor from the lower part of the reaction section; Preferably, at least part of one or more of the C4 olefins, the light gasoline fraction, the heavy aromatic fraction and the slurry oil is fed into the isolinear fluidized bed reactor through the reaction section for recycling; The feed positions of the C4 olefins, the light gasoline fraction and the heavy aromatic fraction are located below the feed position of the diesel, or are fed through the feed position of the diesel; the feed position of the oil slurry is located above the feed position of the diesel.

4. The method according to claim 1, characterized in that: The raw oil includes diesel and heavy oil, the diesel is fed into the isolinear fluidized bed reactor from the lower part of the reaction section, and the heavy oil is fed into the isolinear fluidized bed reactor from the middle part of the reaction section; Preferably, at least part of one or more of the C4 olefins, the light gasoline fraction, the heavy aromatic fraction and the slurry oil is fed into the isolinear fluidized bed reactor through the reaction section for recycling; The feed positions of the C4 olefins, the light gasoline fraction and the heavy aromatic fraction are located below the feed position of the diesel, or are fed through the feed position of the diesel; and the oil slurry is fed through the feed position of the heavy oil.

5. The method according to claim 1, characterized in that The raw oil is diesel, and the diesel is fed into the isolinear fluidized bed reactor from the lower part of the reaction section; Furthermore, step (1) further comprises: The heavy oil is contacted and reacted with a shape-selective molecular sieve catalyst in a riser reactor; In step (2), a portion of the oil mixture is derived from the contact reaction between the diesel and the shape-selective molecular sieve catalyst, and another portion is derived from the contact reaction between the heavy oil and the shape-selective molecular sieve catalyst; in step (4), a portion of the regenerated catalyst is returned to the isolinear fluidized bed reactor for recycling, and another portion of the regenerated catalyst is returned to the riser reactor for recycling; Preferably, at least part of one or more of the C4 olefins, the light gasoline fraction, the heavy aromatic fraction and the slurry oil is fed into the riser reactor for recycling; The feed positions of the C4 olefins, the light gasoline fraction and the heavy aromatic fraction are located below the feed position of the heavy oil, and the slurry oil is fed through the feed position of the heavy oil.

6. The method according to any one of claims 3 to 5, characterized in that: The diesel is selected from a combination of one or more of straight-run diesel, catalytic cracking diesel and hydrogenated diesel; and / or, The boiling point of the diesel is 180-380°C and the density is less than or equal to 850kg / m 3 .

7. The method according to claim 4 or 5, characterized in that: The heavy oil is wax oil and / or residual oil.

8. The method according to any one of claims 3 to 5, characterized in that: The conditions for the contact reaction between the diesel and the shape-selective molecular sieve catalyst in step (1) include: The reaction temperature is 620-720° C., the reaction pressure is 0.2-0.5 MPa, the reaction time is 3.0-7.0 seconds, and the weight ratio of the shape-selective molecular sieve catalyst to the diesel is (6-10):1; The diesel is fed into the isolinear fluidized bed reactor under fluidization of a fluidizing medium; The fluidizing medium is atomized water, and the mass ratio of the atomized water to the diesel is (0.20-0.30):1; The oil and gas linear velocity in the reaction zone is 1.0-2.0 m / s; and / or, The method further comprises the following steps before step (1): Preheating the feedstock oil to a preheating temperature of 200 to 400° C., preferably 260 to 360° C.; The preheating is carried out by heating in a heating furnace, or by exchanging heat between the crude oil and the chemical material obtained from step (3).

9. The method according to claim 5, characterized in that The conditions for the contact reaction between the heavy oil and the shape-selective molecular sieve catalyst in the riser reactor include: The reaction temperature is 620-720° C., the reaction pressure is 0.2-0.5 MPa, the weight ratio of the shape-selective molecular sieve catalyst to the heavy oil is (6-10):1, and the reaction time is 3.0-7.0 seconds; The heavy oil is fed into the riser reactor under fluidization of a fluidizing medium; The fluidizing medium is atomized water, and the mass ratio of the atomized water to the heavy oil is (0.20-0.30):1; The oil and gas linear velocity in the riser reactor is 2.0-12.0 m / s.

10. The method according to any one of claims 1 to 5, characterized in that: In step (3), the oil-gas separation system is selected from a combination of one or more of two or more fractionation towers with a theoretical plate number greater than 20, an absorption stabilization system, and a gas separation system; Propylene, H2 and C1-C4 alkanes, a BTX fraction and a methyl naphthalene oil fraction are also obtained through the separation described in step (3).

11. The method according to any one of claims 1 to 5, characterized in that: In step (4): The regeneration temperature of the regenerator is 640-780°C and the pressure is 0.3-0.6MPa; The circulation rate of the regenerated catalyst is 150-200 kg / (m 2 ·Second); The regeneration atmosphere in the regenerator is selected from one of air, oxygen-enriched and pure oxygen; The flue gas is optionally returned to the regenerator for recycling after heat exchange, and the temperature of the flue gas returned to the regenerator for recycling is 340-580°C.

12. A system for producing chemical materials including ethylene based on an isolinear fluidized bed reactor, characterized in that: The system comprises a constant linear velocity fluidized bed reactor (1), a cyclone separator (IV-1), a settler (IV), an oil-gas separation system (6) and a regenerator (20); The isolinear fluidized bed reactor (1) is provided with a reactor pre-lifting section (I), a reactor reaction section (II), a reactor outlet section (III) and a catalyst stripping section (IV-2); the catalyst in the isolinear fluidized bed reactor (1) flows in an upward manner; the cyclone separator (IV-1) and the settler (IV) are located above the catalyst stripping section (IV-2); the inner diameter of the reactor outlet section (III) is smaller than that of the reactor reaction section (II); The outlet of the pre-lifting section (I) of the reactor is connected to the inlet of the reaction section (II) of the reactor, and the outlet of the reaction section (II) of the reactor is connected to the inlet of the outlet section (III) of the reactor; The reactor reaction section (II) is a variable diameter reaction section, and the inner diameter of the reactor reaction section (II) gradually decreases from top to bottom; a light hydrocarbon feedstock oil inlet (2) and a first atomizing steam inlet (3) are provided at the lower part of the reactor reaction section (II), and the light hydrocarbon feedstock oil inlet (2) and the first atomizing steam inlet (3) are connected; The oil agent outlet of the reactor outlet section (III) is connected to the oil agent inlet of the cyclone separator (IV-1), the catalyst outlet of the cyclone separator (IV-1) is connected to the inlet of the settler (IV), and the oil and gas outlet of the cyclone separator (IV-1) is connected to the oil and gas inlet of the oil and gas separation system (6); The outlet of the settler (IV) is connected to the inlet of the catalyst stripping section (IV-2), the catalyst outlet of the catalyst stripping section (IV-2) is connected to the inlet of the catalyst to be regenerated of the regenerator (20), and the oil and gas outlet of the catalyst stripping section (IV-2) is connected to the oil and gas separation system (6); The regenerator (20) is provided with an oxygen-containing regeneration gas inlet (21) and a flue gas outlet (23), the flue gas outlet (23) is connected to the oxygen-containing regeneration gas inlet (21) through a flue gas circulation system (24), the regenerated catalyst outlet of the regenerator (20) is connected to the catalyst inlet of the reactor pre-lift section (I) through a first regeneration agent delivery pipeline (22), and the bottom of the reactor pre-lift section (I) is provided with a first fluidizing medium inlet (4); The oil-gas separation system (6) is provided with an ethylene outlet (7), a propylene outlet (8), an H2 and C1-C4 alkane outlet (9), a C4 olefin outlet (10), a light gasoline fraction outlet (11), a BTX fraction outlet (12), a heavy aromatic fraction outlet (13), a methyl naphthalene oil fraction outlet (14) and an oil slurry outlet (15); Preferably, the oil and gas outlet of the cyclone separator (IV-1) is connected to the oil and gas inlet of the oil and gas separation system (6) through a reaction oil and gas pipeline (5), and the oil and gas outlet of the catalyst stripping section (IV-2) is connected to the oil and gas inlet of the oil and gas separation system (6) through the reaction oil and gas pipeline (5); Preferably, a stripping medium inlet (18) is provided at the lower portion of the catalyst stripping section (IV-2); Preferably, the catalyst outlet of the catalyst stripping section (IV-2) is connected to the catalyst inlet to be regenerated of the regenerator (20) via a regenerated catalyst delivery pipeline (19); Preferably, a first heavy feedstock oil inlet (16) and a second atomizing steam inlet (17) are provided in the middle of the reaction section (II) of the reactor, and the first heavy feedstock oil inlet (16) is connected to the second atomizing steam inlet (17); Preferably, the reactor reaction section (II) is provided with a first recycling inlet and a second recycling inlet, wherein the first recycling inlet and the second recycling inlet are respectively located below and above the light hydrocarbon feedstock inlet (2); The C4 olefin outlet (10), the light gasoline fraction outlet (11) and the heavy aromatic fraction outlet (13) are respectively connected to the first recycle inlet, or are respectively connected to the light hydrocarbon feedstock oil inlet (2); the slurry oil outlet (15) is connected to the second recycle inlet, or is connected to the first heavy feedstock oil inlet (16).

13. The system according to claim 12, characterized in that The system is further provided with a riser reactor (25), wherein the riser reactor (25) is provided with a second heavy feedstock oil inlet (28) and a third atomizing steam inlet (29), wherein the second heavy feedstock oil inlet (28) is connected to the third atomizing steam inlet (29); The regenerated catalyst outlet of the regenerator (20) is connected to the catalyst inlet at the bottom of the riser reactor (25) through a second regeneration agent delivery pipeline (27), and a second fluidizing medium inlet (26) is also provided at the bottom of the riser reactor (25); The oil agent outlet of the riser reactor (25) is connected to the oil agent inlet of the cyclone separator (IV-1); Preferably, the riser reactor (25) is provided with a third recycle port, and the third recycle port is located below the second heavy feedstock oil inlet (28); the C4 olefin outlet (10), the light gasoline fraction outlet (11) and the heavy aromatic fraction outlet (13) are respectively connected to the third recycle port; and the slurry oil outlet (15) is connected to the second heavy feedstock oil inlet (28).

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