Method and system for producing low-carbon olefin by direct catalytic cracking of crude oil

Abstract

The invention relates to a method and a system for producing low-carbon olefin by direct catalytic cracking of crude oil, and the method comprises the following steps: the crude oil sequentially enters a first reaction section and a second reaction section of a catalytic cracking reactor for catalytic cracking reaction, and the reaction product and a spent catalyst are subjected to gas-solid separation; the spent catalyst is sequentially subjected to steam stripping, green coke supplementation and charring regeneration and then returns to the reactor for recycling; and separating the reaction product to obtain ethylene, propylene, a difficult-to-convert component and other products, wherein the difficult-to-convert component enters a second reaction zone of the first reaction section for further reaction to obtain ethylene and propylene. When the catalytic cracking method and system are used for the catalytic cracking reaction of the crude oil, the processing flow of the crude oil is further shortened, the atom utilization rate of the crude oil is improved, the yields of ethylene and propylene are high, and meanwhile, the possible problem of heat balance is solved.

Description

Technical Field

[0001] The present application relates to the field of petrochemical engineering, and in particular to a catalytic cracking method and system for producing low-carbon olefins from crude oil. Background Art

[0002] Ethylene, propylene and BTX (benzene-toluene-xylene) are key basic organic synthetic raw materials with huge demand. They can be used to produce a variety of organic chemical products, including many important high-end organic chemical products. They are closely related to people's food, clothing, housing and transportation, and are an important guarantee for the country's high-quality and sustainable development. The existing technical route for producing propylene and BTX from petroleum is developed on the basis of the traditional petroleum refining process that mainly produces oil products. There are problems such as long production process, low chemical yield and insignificant economic benefits. The technical measures to solve this problem are to develop key core technologies that mainly produce chemicals and can direct the conversion of crude oil hydrocarbon molecules into chemicals. Therefore, in recent years, petrochemical companies at home and abroad have been actively exploring the technical route of directly producing chemicals from crude oil, so as to make the processing path from crude oil to low-carbon olefins and BTX and other chemicals shorter, with lower energy consumption and smaller investment.

[0003] WO2005113722A3 and CN200780047937.2 disclose a process for producing crude oil directly into chemicals, wherein the crude oil directly enters a steam cracking furnace, and is flash evaporated to separate light components and heavy components, the light components (gaseous components) enter the steam cracking furnace for cracking, and the heavy components (liquid components) are used as refinery raw materials.

[0004] CN 201380015214.X discloses a process for producing olefins and aromatics from crude oil by integrating hydroprocessing, steam cracking and catalytic cracking processes. After the crude oil is hydroprocessed, impurities such as sulfur and high-boiling substances are removed, and the hydrogenated products are separated by distillation. The light components enter the steam cracking unit, and the heavy components are subjected to the catalytic cracking unit to maximize the production of olefins.

[0005] CN201780078199.1 discloses a method and system for converting crude oil into petrochemicals and fuel products by integrating steam cracking and fluid catalytic cracking. Crude oil is separated into straight-run naphtha and lighter component fractions, one or more intermediate distillate fractions, and atmospheric residue fractions. Vacuum distillate oil is then separated from the atmospheric residue fraction as a catalytic cracking feedstock. The light fraction is hydrogenated and used as naphtha and diesel fuel oil.

[0006] The above crude oil processing routes all use steam cracking as the main technical means to produce light olefins. Due to the high energy consumption of steam cracking technology and the poor flexibility of product solutions, researchers are also actively developing technical solutions for producing light olefins by catalytic cracking.

[0007] The method for preparing low-carbon olefins and aromatics by catalytic cracking of crude oil disclosed in CN20181189551.1 and CN201811190135.3 comprises the following steps: after desalting and dehydrating the crude oil, the crude oil is divided into light and heavy components, and the light component, i.e., light feed, and the heavy component, i.e., heavy feed, are respectively placed in two catalytic cracking reactors, and are contacted with a high-temperature catalyst under a steam atmosphere to react to produce low-carbon olefins and aromatics. Alternatively, the light component and the heavy component react in different reaction zones of the same reactor.

[0008] CN 201810523356.1 discloses a method for processing a whole fraction of crude oil. The method separates the whole fraction of crude oil to obtain light distillate oil, middle distillate oil and heavy distillate oil. The middle distillate oil and the heavy distillate oil are reacted in a first riser, and the light distillate oil is reacted in a fluidized bed reactor connected in series with the riser. The reaction conditions in the reactor vary according to the properties of the raw materials.

[0009] Existing crude oil catalytic cracking technologies all use crude oil distillation to separate fractions, and select technical routes with different catalytic cracking reaction environments based on the performance differences of different fractions, but have failed to achieve a truly direct catalytic cracking technology route for crude oil. Summary of the invention

[0010] The purpose of this application is to provide a method and system for direct catalytic cracking of crude oil whole fractions based on the current catalytic cracking technology, which can not only improve the yield and selectivity of ethylene and propylene produced by catalytic cracking of crude oil, but also solve the problem of insufficient heat in the potential catalytic cracking reaction of crude oil.

[0011] The first aspect of the present invention provides a method for producing light olefins by direct catalytic cracking of crude oil, comprising:

[0012] (1) A first raw material and a regenerated catalyst from a regenerator sequentially enter a first reaction zone and a second reaction zone of a first reaction zone of a catalytic cracking reactor to undergo a catalytic cracking reaction;

[0013] (2) The reaction products and the catalyst to be regenerated enter the oil separation equipment through the outlet zone for gas-solid separation. The separated reaction oil and gas are led out of the device for further separation to obtain ethylene, propylene, difficult-to-convert components and other products;

[0014] (3) The separated catalyst to be regenerated is stripped and then enters the auxiliary regenerator, where it is mixed with the regenerated catalyst from the regenerator and heated, and then contacts with the coking raw material to produce a coking reaction, thereby obtaining a coking catalyst with coke;

[0015] (4) the coked catalyst with coke enters the regenerator, contacts with the oxygen-containing gas to cause a complete combustion reaction of the coke to obtain a regenerated catalyst, the first part of the regenerated catalyst is returned to the first reaction zone of the first reaction stage of the catalytic cracking reactor for recycling, and the second part of the regenerated catalyst is returned to the second reaction zone of the first reaction stage at the lower part of the catalytic cracking reactor for reaction;

[0016] (5) The second raw material is fed into the second reaction zone of the first reaction section of the catalytic cracking reactor, where it contacts the mixture of the regenerated catalyst and the fresh catalyst to undergo a cracking reaction. The oil-agent mixture generated by the reaction enters the first reaction zone of the first reaction section, where it is mixed with the existing stream in the first reaction zone and continues to react;

[0017] Wherein, the first raw material is paraffin-based crude oil, paraffin-intermediate-based crude oil and / or intermediate-paraffin-based crude oil;

[0018] The second raw material is self-produced by the device and / or other difficult-to-convert components, and the difficult-to-convert components are C4 components and / or light distillate oil with a final boiling point of less than 280-360°C.

[0019] The method according to the first aspect, wherein the C4 component comprises gaseous hydrocarbons rich in C4 fraction produced by the device itself and / or other devices, wherein the content of C4 olefins in the gaseous hydrocarbons rich in C4 fraction is greater than 50% by weight;

[0020] Preferably, the difficult-to-convert component is the C4 fraction produced by the device.

[0021] According to the method of the first aspect, the difficult-to-convert components include a light distillate oil produced by the device with a final boiling point of less than 280-360° C. and optionally one or more of the following fractions:

[0022] Straight-run naphtha, straight-run kerosene, and straight-run diesel produced by other primary processing units;

[0023] Other secondary processing units produce topped oil, raffinate oil, hydrocracked light naphtha, pentane oil, coker gasoline, Fischer-Tropsch synthetic oil, catalytic cracking light gasoline, hydrogenated gasoline, and hydrogenated diesel.

[0024] According to the method of the first aspect, the reaction conditions of the first reaction zone of the first reaction section of the catalytic cracking reactor include:

[0025] The reaction temperature is 550-650°C;

[0026] The reaction time is 0.1-5 seconds; and / or

[0027] The weight ratio of agent to oil is (5-30):1;

[0028] Preferably, the first raw material enters the first reaction zone of the first reaction stage after being preheated and steam atomized, the preheating temperature is 180-350°C, and the water-oil weight ratio is (0.05-0.5):1.

[0029] According to the method of the first aspect, the reaction conditions of the second reaction section of the catalytic cracking reactor include:

[0030] The reaction temperature is 450-600°C;

[0031] Weight hourly space velocity is 1-20 hours -1 ; and / or

[0032] The method according to the first aspect, wherein the weight ratio of fresh catalyst to regenerated catalyst in the second reaction zone of the first reaction section is 0.01-0.3:1.

[0033] According to the method of the first aspect, the reaction conditions of the second reaction zone of the first reaction section include:

[0034] The reaction temperature is 600-720°C;

[0035] Response time is 0.1-3 seconds; and / or

[0036] The weight ratio of agent to oil is (5-50):1;

[0037] Preferably, the second raw material is fed into the second reaction zone of the first reaction stage after being steam atomized, and the water-oil weight ratio is (0.05-0.5):1.

[0038] The method according to the first aspect, wherein the outlet temperature of the auxiliary regenerator is 550-650°C;

[0039] Line speed of 1.2-2.2 m / s; and / or

[0040] The coking raw material is straight-run distillate oil or secondary processed distillate oil; preferably, the secondary processed distillate oil is selected from one or more of the following: catalytic cracking diesel, catalytic cracking slurry oil, coker gasoline, coker diesel and coker wax oil.

[0041] A second aspect of the present invention provides a catalytic cracking system, comprising:

[0042] The catalytic cracking reaction unit comprises:

[0043] The first reaction section comprises a first reaction zone and a second reaction zone, wherein the first reaction zone is provided with an oil agent inlet, a feedstock oil inlet, a first regenerated catalyst inlet and a first oil agent mixture outlet, and the second reaction zone is provided with a pre-lifting medium inlet, a second regenerated catalyst inlet, a fresh catalyst inlet, a difficult-to-convert feedstock inlet and a second oil agent mixture outlet, and the second oil agent mixture outlet is connected to the oil agent inlet of the first reaction zone;

[0044] A second reaction section is provided with a first oil-agent mixture inlet, and the first oil-agent mixture outlet extends through the first oil-agent mixture inlet to the interior of the second reaction section;

[0045] An oil agent separation device is provided with an oil agent inlet, a catalyst outlet and a reaction product outlet, wherein the oil agent inlet of the oil agent separation device is connected to the second reaction stage, so that the oil agent mixture from the second reaction stage is separated into reaction oil gas and catalyst to be generated by the oil agent separation device;

[0046] and

[0047] A settler, the settler is arranged in the second reaction section, and is used to settle and collect the catalyst to be regenerated separated by the oil agent separation device. A stripping section is arranged below the settler, and is used to strip the catalyst to be regenerated. The stripping section is provided with an outlet for the catalyst to be regenerated and an inlet for a stripping medium.

[0048] A reaction product separation unit, the reaction product separation unit is connected to the oil agent separation device and is used to separate the reaction oil gas separated by the oil agent separation device;

[0049] Catalyst regeneration unit, comprising:

[0050] an auxiliary regenerator, used for contacting the catalyst to be regenerated separated by the catalytic cracking reaction unit with the coking raw material to generate a coking reaction to obtain a coking catalyst with coke, wherein the auxiliary regenerator is provided with an inlet for the catalyst to be regenerated, an inlet for the fluidized medium, at least one inlet for the coking raw material and an outlet for the coking catalyst, wherein the inlet for the catalyst to be regenerated is fluidically connected to the outlet for the catalyst to be regenerated of the stripping section of the settler; and

[0051] A regenerator, wherein the regenerator is provided with a coke catalyst inlet, an oxygen-containing gas inlet, a gas distributor, a cyclone separator, a regenerated flue gas pipeline and at least one regenerated catalyst outlet; the raw catalyst inlet of the regenerator is fluidly connected to the coke catalyst outlet of the auxiliary regenerator; one regenerated catalyst outlet is connected to the first regenerated catalyst inlet of the first reaction zone of the first reaction stage, for recycling a part of the regenerated catalyst back to the first reaction zone of the first reaction stage; one regenerated catalyst outlet is fluidly connected to the second regenerated catalyst inlet of the second reaction zone of the first reaction stage, so that the regenerated catalyst is recycled back to the second reaction zone of the first reaction stage;

[0052] A regenerated catalyst circulation pipeline connecting the auxiliary regenerator and the regenerator is arranged between the auxiliary regenerator and the regenerator, so as to allow a part of the regenerated catalyst to enter the auxiliary regenerator and mix with the catalyst to be regenerated to react with the coking raw material to form a coke.

[0053] According to the system of the second aspect, the distance between the connection port of the external catalyst circulation pipe on the auxiliary regenerator and the bottom of the auxiliary regenerator is 5% to 10% of the height of the auxiliary regenerator;

[0054] The distance between the coke raw material inlet and the bottom of the auxiliary regenerator is 20% to 50% of the height of the auxiliary regenerator.

[0055] Compared with the prior art, the method and system of the present invention have the following beneficial effects:

[0056] 1) It can realize direct catalytic cracking of crude oil, reduce the crude oil distillation process, simplify the process and reduce operating costs.

[0057] 2) In the process of catalytic cracking of crude oil, the single-pass conversion rate is not pursued. The light distillate oil that is difficult to convert is recycled. By setting up specific reaction zones, a higher overall conversion rate and higher light olefin selectivity can be achieved.

[0058] 3) The light distillate oil reaction zone is upstream of the crude oil reaction zone. After the high-temperature regenerated catalyst passes through the light distillate oil reaction zone, a small amount of carbon deposits on the catalyst passivate the metal on the catalyst. When it contacts and reacts with crude oil again, the impact of heavy metals in the crude oil is reduced.

[0059] 4) Setting up an auxiliary regenerator can solve the problem of insufficient heat balance when processing high-quality crude oil.

[0060] By adopting the catalytic cracking method of the present application, chemical raw materials such as ethylene and propylene can be efficiently produced directly from crude oil, which not only further shortens the crude oil processing process, helps refineries transform, develop and extend from oil refining to chemical raw material production, but also improves the economic benefits of refineries. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] The accompanying drawings are used to provide a further understanding of the present application and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present application but do not constitute a limitation to the present application. In the accompanying drawings:

[0062] Figure 1 A schematic diagram of a process for producing light olefins by direct catalytic cracking of crude oil according to an embodiment of the present application.

[0063] Description of reference numerals:

[0064] I, first reaction zone of first reaction section; II, second reaction section; III, second reaction zone of first reaction section; 100, catalytic cracking reactor; 101, pre-lift medium pipeline; 102, fresh catalyst pipeline; 103, first regeneration agent pipeline; 104, first feed pipeline; 105, second feed pipeline; 106, second regeneration agent pipeline; 107, outlet of first reaction section; 200, settler; 201, stripping section; 202, stripping medium; 203, waiting The raw material is an inclined pipe; 204, an oil agent separation device; 205, a gas collecting chamber; 206, a large oil and gas pipe; 300, an auxiliary regenerator; 301, a fluidizing medium inlet; 302, a first gas distributor; 303, an external catalyst circulation pipe; 304, a fuel oil inlet; 305, a catalyst distributor; 400, a regenerator; 401, an oxygen-containing gas inlet; 402, a second gas distributor; 404, a cyclone separator; 405, a regenerated flue gas pipeline; 406, a regenerated catalyst outlet. DETAILED DESCRIPTION

[0065] 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.

[0066] 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.

[0067] Any specific numerical value disclosed herein (including the endpoint of the numerical range) is not limited to the exact value of the numerical value, but should be understood to also cover values ​​close to the exact value, such as all possible numerical values ​​within the range of ±5% of the exact value. In addition, for the disclosed numerical range, the endpoint values ​​of the range, the endpoint values ​​and the specific point values ​​in the range, and the specific point values ​​can be arbitrarily combined to obtain one or more new numerical ranges, and these new numerical ranges should also be regarded as specifically disclosed herein.

[0068] In this article, low-carbon olefins are a general term for ethylene, propylene and butene, and light aromatics (BTX) are a general term for benzene (BTX), toluene (T) and xylene (X).

[0069] In the present application, the terms "upstream" and "downstream" are based on the flow direction of the reactants. For example, when the reactants flow from bottom to top, "upstream" means the position below, while "downstream" means the position above.

[0070] Unless otherwise specified, the terms used herein have the same meaning as commonly understood by those skilled in the art. If a term is defined herein and its definition is different from the commonly understood meaning in the art, the definition herein shall prevail.

[0071] 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.

[0072] The present invention provides a method for producing light olefins by direct catalytic cracking of crude oil, comprising:

[0073] (1) A first raw material and a regenerated catalyst from a regenerator sequentially enter a first reaction section and a second reaction section of a catalytic cracking reactor to undergo a catalytic cracking reaction;

[0074] (2) The reaction products and the catalyst to be regenerated enter the oil separation equipment through the outlet zone for gas-solid separation. The separated reaction oil and gas are led out of the device for further separation to obtain ethylene, propylene, difficult-to-convert components and other products;

[0075] (3) The separated catalyst to be regenerated is stripped and then enters the auxiliary regenerator, where it is mixed with the regenerated catalyst from the regenerator and heated, and then contacts with the coking raw material to produce a coking reaction, thereby obtaining a coking catalyst with coke;

[0076] (4) The coked catalyst with coke enters the regenerator, contacts with the oxygen-containing gas to cause a complete combustion reaction of the coke to obtain a regenerated catalyst, and the first part of the regenerated catalyst is returned to the first reaction section of the catalytic cracking reactor for recycling, and the second part of the regenerated catalyst is returned to the second reaction zone of the first reaction section at the lower part of the catalytic cracking reactor for reaction;

[0077] (5) The second raw material is fed into the second reaction zone of the first reaction section of the catalytic cracking reactor, where it contacts the mixture of the regenerated catalyst and the fresh catalyst to undergo a cracking reaction. The oil-agent mixture generated by the reaction enters the first reaction section and is mixed with the existing stream in the first reaction section to continue the reaction;

[0078] Wherein, the first raw material is paraffin-based crude oil, paraffin-intermediate-based crude oil and / or intermediate-paraffin-based crude oil;

[0079] The second raw material is self-produced by the device and / or other difficult-to-convert components, and the difficult-to-convert components are C4 fractions and / or light distillate oil with a final boiling point of less than 280-360°C.

[0080] The present application will be further described below with reference to the preferred implementation modes shown in the accompanying drawings, but the present application is not limited thereby.

[0081] Figure 1A preferred embodiment of the catalytic cracking method of the present application is provided, wherein the catalytic cracking reactor 100 includes, from bottom to top, the second reaction zone III of the first reaction section, the first reaction zone I of the first reaction section, and the second reaction section II. The outlet of the second reaction zone III of the first reaction section is provided with a first feed pipeline 104 for the inlet of the difficult-to-convert raw material, and the bottom of the first reaction zone I of the first reaction section is provided with a second feed pipeline 105 for the raw material feed port and a second regeneration agent pipeline 106 for the regeneration catalyst inlet.

[0082] The pre-lifting medium enters the bottom of the second reaction zone III of the first reaction stage through the pre-lifting medium pipeline 101. The lifting medium can be dry gas, water vapor or a mixture thereof. The hot regenerated catalyst from the first regeneration agent pipeline 103 and the fresh catalyst from the fresh catalyst pipeline 102 enter the second reaction zone III of the first reaction stage, move upward and mix under the lifting effect of the pre-lifting medium, the difficult-to-convert raw material and the atomized steam are injected into the middle and lower part of the second reaction zone III of the first reaction stage through the first feed pipeline 104, and are mixed, contacted and reacted with the existing catalyst in the catalytic cracking reactor, and the generated oil-agent mixture moves upward into the first reaction zone I of the first reaction stage, the hot regenerated catalyst from the second regeneration agent pipeline 106 is mixed and moves upward, the reaction raw material such as preheated crude oil and atomized steam are injected into the bottom of the first reaction zone I of the first reaction stage through the second feed pipeline 105, and are mixed and contacted with the existing oil gas and catalyst in the catalytic cracking reactor, and the catalytic cracking reaction is carried out in the process of passing through the first reaction zone I of the first reaction stage from bottom to top. The reaction oil gas and catalyst flow upward through the first reaction stage outlet 107 into the second reaction stage II to continue the catalytic cracking reaction. The catalyst with coke generated by the reaction and the reaction oil gas enter the oil agent separation device 204 such as a cyclone separator for gas-solid separation. The reaction oil gas obtained by separation is led out of the device through the gas collecting chamber 205 and the large oil and gas pipe 206 to enter the subsequent separation system; the catalyst to be regenerated with coke obtained by separation enters the lower part of the settler 200 and enters the auxiliary regenerator 300 through the inclined pipe to be regenerated 203.

[0083] The fluidizing medium enters the auxiliary regenerator 300 from the bottom of the auxiliary regenerator 300 through the fluidizing medium inlet 301 and the first gas distributor 302. The fluidizing medium may be nitrogen, water vapor or a mixture thereof. The high-temperature regenerated catalyst from the external catalyst circulation pipe 303 enters the lower part of the auxiliary regenerator 300, mixes with the fluidizing gas and moves upward, contacts the catalyst to be regenerated from the catalyst inlet to be regenerated inclined pipe 203 and continues to move upward, contacts the supplementary fuel oil from the fuel oil inlet 304 and undergoes a coking reaction; the catalyst with char and coke flows upward, enters the regenerator 400 through the catalyst distributor 305, contacts the oxygen-containing gas injected through the oxygen-containing gas inlet 401 and the second gas distributor 402 and undergoes a complete combustion reaction, completely releasing heat, and the regenerated catalyst is sent out of the regenerator through the regenerated catalyst outlet 406, a part of the regenerated catalyst is supplied to the first reaction zone I of the first reaction stage for recycling through the second regeneration agent pipeline 106, and a part of the regenerated catalyst is supplied to the second reaction zone III of the first reaction stage through the first regeneration agent pipeline 103; the regenerated flue gas is separated from the entrained catalyst by the cyclone separator 404 and enters the energy recovery system through the regeneration flue gas pipeline 405.

[0084] The crude oil applicable to the catalytic cracking method provided in the present application is selected from paraffin-based crude oil, paraffin-intermediate-based crude oil and intermediate-paraffin-based crude oil. The first key component of the paraffin-based crude oil and any component in the second key group belong to paraffin-based properties; the first key component of the paraffin-intermediate-based crude oil is paraffin-based and the second key group is intermediate-based; the first key component of the intermediate-paraffin-based crude oil is intermediate-based and the second key group is paraffin-based.

[0085] In one embodiment, the crude oil has a characteristic factor K value of not less than 12.0 and a relative density of 780-900 kg / m 3 .

[0086] In the present application, the difficult-to-convert component is one of the carbon four components or the light distillate oil with a final boiling point less than 280-360°C, or a mixture thereof.

[0087] In one embodiment, the C4 component refers to a low molecular hydrocarbon compound that exists in gaseous form at room temperature and pressure with C4 fraction as the main component, including alkanes, alkenes and alkynes with 4 carbon atoms in the molecule. It includes gaseous hydrocarbon products rich in C4 fraction produced by the device of the present invention, and may also include gaseous hydrocarbons rich in C4 fraction produced by other device processes, among which the C4 fraction produced by the device of the present invention is preferred. The C4 hydrocarbons are preferably C4 fractions rich in olefins, wherein the content of C4 olefins is greater than 50% by weight, preferably greater than 60% by weight, and preferably above 70% by weight.

[0088] In one embodiment, the C4 component includes gaseous hydrocarbons rich in C4 fraction produced by the device itself and / or other devices, wherein the content of C4 olefins in the gaseous hydrocarbons rich in C4 fraction is greater than 50% by weight;

[0089] Preferably, the difficult-to-convert component is the C4 fraction produced by the device.

[0090] In one embodiment, the difficult-to-convert components include a light distillate oil produced by the device with a final boiling point of less than 280-360° C. and optionally one or more of the following fractions:

[0091] Straight-run naphtha, straight-run kerosene, and straight-run diesel produced by other primary processing units;

[0092] Other secondary processing units produce topped oil, raffinate oil, hydrocracked light naphtha, pentane oil, coker gasoline, Fischer-Tropsch synthetic oil, catalytic cracking light gasoline, hydrogenated gasoline, and hydrogenated diesel.

[0093] In one embodiment, the reaction conditions in the first reaction zone of the first reaction section of the catalytic cracking reactor include:

[0094] The reaction temperature is 550-650°C;

[0095] The reaction time is 0.1-5 seconds; and / or

[0096] The weight ratio of agent to oil is (5-30):1;

[0097] Preferably, the first raw material enters the first reaction zone of the first reaction stage after being preheated and steam atomized, the preheating temperature is 180-350°C, and the water-oil weight ratio is (0.05-0.5):1.

[0098] In one embodiment, the reaction conditions of the second reaction section of the catalytic cracking reactor include:

[0099] The reaction temperature is 450-600°C;

[0100] Weight hourly space velocity is 1-20 hours -1 ; and / or

[0101] In one embodiment, the weight ratio of the fresh catalyst to the regenerated catalyst in the second reaction zone of the first reaction stage is 0.01-0.3:1.

[0102] In one embodiment, the reaction conditions of the second reaction zone of the first reaction stage include:

[0103] The reaction temperature is 600-720°C;

[0104] Response time is 0.1-3 seconds; and / or

[0105] The weight ratio of agent to oil is (5-50):1;

[0106] Preferably, the second raw material is fed into the second reaction zone of the first reaction stage after being steam atomized, and the water-oil weight ratio is (0.05-0.5):1.

[0107] In one embodiment, a catalyst mixing zone is disposed at the lower portion of the second reaction zone of the first reaction stage, and the fresh catalyst and the regenerated catalyst are mixed in the catalyst mixing zone before entering the second reaction zone of the first reaction stage.

[0108] In one embodiment, the outlet temperature of the auxiliary regenerator is 550-650°C;

[0109] Line speed of 1.2-2.2 m / s; and / or

[0110] The coking raw material is straight-run distillate oil or secondary processed distillate oil; preferably, the secondary processed distillate oil is selected from one or more of the following: catalytic cracking diesel, catalytic cracking slurry oil, coker gasoline, coker diesel and coker wax oil.

[0111] In the present application, the auxiliary regenerator may be provided with one or more, for example, one, two or more fuel oil inlets, and the one or more fuel oil (coking raw material) inlets may be independently arranged at the outlet end of the auxiliary regenerator, or at the bottom of the auxiliary regenerator. Further preferably, the fuel oil inlets are independently arranged in the middle and upstream of the auxiliary regenerator. The fuel oil may include a straight run distillate or a secondary processed distillate. Preferably, the secondary processed distillate may be selected from a mixed oil of one or more of catalytic cracking diesel, catalytic cracking slurry, coker gasoline, coker diesel and coker gas oil.

[0112] In one embodiment, the distance between the connection port of the external catalyst circulation pipe on the auxiliary regenerator and the bottom of the auxiliary regenerator is 5% to 10% of the height of the auxiliary regenerator.

[0113] In one embodiment, the outlet temperature of the auxiliary regenerator is 550-650°C.

[0114] In one embodiment, the linear velocity of the auxiliary regenerator is 1.2 m / s-2.2 m / s, the atomizing medium of the auxiliary regenerator is nitrogen, and the mass ratio of the atomizing medium to the combustion oil is 1:1 to 1:100.

[0115] In one embodiment, the temperature in the regenerator is 550-750°C, more preferably 600-730°C, and further preferably 650-700°C; the gas superficial linear velocity is 0.3-3 m / s, preferably 0.5-2.5 m / s, and more preferably 0.6-1.5 m / s; the average residence time of the regenerated catalyst is 0.6-83 minutes, preferably 0.8-6 minutes, and more preferably 1-5 minutes.

[0116] In one embodiment, the catalyst used in the present invention comprises, based on the dry weight of the catalyst, 1-50% by weight, preferably 5-45% by weight, more preferably 10-40% by weight of zeolite; 5-99% by weight, preferably 10-80% by weight, more preferably 20-70% by weight of inorganic oxides; and 0-70% by weight, preferably 5-60% by weight, more preferably 10-50% by weight of clay.

[0117] In one embodiment, the zeolite includes a medium-pore zeolite and an optional large-pore zeolite, wherein the medium-pore zeolite is selected from ZSM series zeolites, ZRP zeolites, and any combination thereof; the large-pore zeolite is selected from rare earth Y-type zeolite, rare earth hydrogen Y-type zeolite, ultrastable Y-type zeolite and high silicon Y-type zeolite, and any combination thereof.

[0118] In one embodiment, the medium pore zeolite accounts for 10-100 wt %, preferably 50-90 wt %, of the total weight of the zeolite on a dry basis.

[0119] In the present application, the medium-pore zeolite and large-pore zeolite follow the conventional definition in the art, that is, the average pore diameter of the medium-pore zeolite is about 0.5-0.6 nm, and the average pore diameter of the large-pore zeolite is about 0.7-1.0 nm.

[0120] As an example, the large-pore zeolite can be selected from one or more of rare earth Y (REY) type zeolite, rare earth hydrogen Y (REHY) type zeolite, ultrastable Y type zeolite obtained by different methods and high silicon Y type zeolite. The medium-pore zeolite can be selected from zeolites with MFI structure, such as ZSM series zeolites and / or ZRP zeolites. Optionally, the above-mentioned medium-pore zeolites can also be modified with non-metallic elements such as phosphorus and / or transition metal elements such as iron, cobalt, and nickel. A more detailed description of ZRP zeolite can be found in U.S. Patent No. 5,232,675A. ZSM series zeolites are preferably selected from one or more mixtures of ZSM-5, ZSM-11, ZSM-12, ZSM-23, ZSM-35, ZSM-38, ZSM-48 and other zeolites of similar structure. A more detailed description of ZSM-5 can be found in U.S. Patent No. 3,702,886A.

[0121] According to the present application, the inorganic oxide is used as a binder, preferably silicon dioxide (SiO2) and / or aluminum oxide (Al2O3). The clay is used as a matrix (ie, a carrier), preferably kaolin and / or halloysite.

[0122] According to the present application, the separation of the reaction product and the catalyst to be produced is well known to those skilled in the art, for example, it can be carried out using a cyclone separator in a settler, and the method of further separating the reaction oil and gas to obtain dry gas, liquefied gas, light distillate oil in difficult-to-convert components, and cracked heavy oil is also well known to those skilled in the art. The dry gas and liquefied gas can be further separated by conventional separation means in the art to obtain target products such as ethylene and propylene and C4 components.

[0123] The present invention also provides a catalytic cracking system, comprising:

[0124] The catalytic cracking reaction unit comprises:

[0125] The first reaction section comprises a first reaction zone and a second reaction zone, wherein the first reaction zone is provided with an oil agent inlet, a feedstock oil inlet, a first regenerated catalyst inlet and a first oil agent mixture outlet, and the second reaction zone is provided with a pre-lifting medium inlet, a second regenerated catalyst inlet, a fresh catalyst inlet, a difficult-to-convert feedstock inlet and a second oil agent mixture outlet, and the second oil agent mixture outlet is connected to the oil agent inlet of the first reaction zone;

[0126] A second reaction section is provided with a first oil-agent mixture inlet, and the first oil-agent mixture outlet extends through the first oil-agent mixture inlet to the interior of the second reaction section;

[0127] an oil agent separation device, which is provided with an oil agent inlet, a catalyst outlet and a reaction product outlet, wherein the oil agent inlet of the oil agent separation device is connected to the second reaction stage, so that the oil agent mixture from the second reaction stage is separated into reaction oil gas and catalyst to be generated by the oil agent separation device; and

[0128] A settler, the settler is arranged in the second reaction section, and is used to settle and collect the catalyst to be regenerated separated by the oil agent separation device. A stripping section is arranged below the settler, and is used to strip the catalyst to be regenerated. The stripping section is provided with an outlet for the catalyst to be regenerated and an inlet for a stripping medium.

[0129] A reaction product separation unit, the reaction product separation unit is connected to the oil agent separation device and is used to separate the reaction oil gas separated by the oil agent separation device;

[0130] Catalyst regeneration unit, comprising:

[0131] an auxiliary regenerator, used for contacting the catalyst to be regenerated separated by the catalytic cracking reaction unit with the coking raw material to generate a coking reaction to obtain a coking catalyst with coke, wherein the auxiliary regenerator is provided with an inlet for the catalyst to be regenerated, an inlet for the fluidized medium, at least one inlet for the coking raw material and an outlet for the coking catalyst, wherein the inlet for the catalyst to be regenerated is fluidically connected to the outlet for the catalyst to be regenerated of the stripping section of the settler; and

[0132] A regenerator, wherein the regenerator is provided with a coke catalyst inlet, an oxygen-containing gas inlet, a gas distributor, a cyclone separator, a regenerated flue gas pipeline and at least one regenerated catalyst outlet; the raw catalyst inlet of the regenerator is fluidly connected to the coke catalyst outlet of the auxiliary regenerator; one regenerated catalyst outlet is connected to the first regenerated catalyst inlet of the first reaction stage, for recycling a portion of the regenerated catalyst back to the first reaction stage; one regenerated catalyst outlet is fluidly connected to the second regenerated catalyst inlet of the second reaction zone of the first reaction stage, so that the regenerated catalyst is recycled back to the second reaction zone of the first reaction stage;

[0133] A regenerated catalyst circulation pipeline connecting the auxiliary regenerator and the regenerator is arranged between the auxiliary regenerator and the regenerator, so as to allow a part of the regenerated catalyst to enter the auxiliary regenerator and mix with the catalyst to be regenerated to react with the coking raw material to form a coke.

[0134] In one embodiment, the distance between the connection port of the external catalyst circulation pipe on the auxiliary regenerator and the bottom of the auxiliary regenerator is 5% to 10% of the height of the auxiliary regenerator;

[0135] The distance between the coke raw material inlet and the bottom of the auxiliary regenerator is 20% to 50% of the height of the auxiliary regenerator.

[0136] In one embodiment, the fluidizing medium of the auxiliary regenerator enters into the auxiliary regenerator through a first gas distributor disposed at the bottom.

[0137] According to the present application, the first gas distributor may be a main air distributor known to those skilled in the art. For example, the main air distributor may be a distribution plate and a distribution pipe. Preferably, the distribution pipe is an annular distribution pipe and a dendrite distribution pipe.

[0138] In the present application, a catalyst distribution plate can be arranged at the position where the catalyst enters the bottom of the regenerator, for example, at the outlet end of the auxiliary regenerator. According to the present application, the catalyst distribution plate can be a distribution plate of various types commonly used in the industry, for example, one or more of a flat plate, an arch, a dish, an annular shape and an umbrella shape. The use of a catalyst distribution plate helps to make the catalyst uniformly contact with the oxygen-rich gas in the axial direction of the regenerator for a charring reaction, improve the charring efficiency, and reduce the occurrence of local hot spots in the catalyst bed.

[0139] By setting up an auxiliary regenerator, the injected fuel oil is mixed with the catalyst under low-temperature, oxygen-deficient fluidized conditions to form coke. The catalyst with coke attached is back-mixed in the auxiliary regenerator so that the coke is evenly distributed on the catalyst, which helps to achieve uniform distribution of catalyst surface temperature.

[0140] In one embodiment, a second gas distributor is provided at the bottom of the regenerator, so that the oxygen-enriched gas injected through the oxygen-enriched gas inlet enters the regenerator through the second gas distributor. According to the present application, the second gas distributor can adopt a main air distributor well known to those skilled in the art. For example, the main air distributor can be a distribution plate and a distribution pipe. Preferably, the distribution pipe is an annular distribution pipe and a dendrite distribution pipe.

[0141] According to the present application, the oil agent separation equipment and the reaction product separation equipment are both well known to those skilled in the art. For example, the oil agent separation equipment may include a cyclone separator, a settler and a stripper, etc., and the reaction product separation equipment may be a distillation tower, etc.

[0142] Example

[0143] The following examples will further illustrate the present application, but are not intended to limit the present application.

[0144] The raw oil used in the following examples and comparative examples is Subei crude oil from Jiangsu Oilfield, and its properties are shown in Table 1. The catalyst used is a commercial catalytic cracking catalyst purchased from the Catalyst Branch of Sinopec Corporation, with the trade name DMMC-2.

[0145] Example 1

[0146] Using the feedstock oil and DMMC-2 catalyst shown in Table 1, Figure 1 The experiment was carried out on the pilot plant shown in the figure, wherein the structure of the reactor used is as follows:

[0147] The total height of a conventional riser reactor (first reaction stage) connected in series with a fluidized bed reactor (second reaction stage) is 7 meters, wherein the second reaction zone of the first reaction stage is arranged at the lower part of the first reaction stage, with a height of 1 meter and an inner diameter of 0.2 meters.

[0148] The inner diameter of the auxiliary regenerator is 0.3 meters and the height is 2 meters. The distance between the fuel oil inlet 304 of the auxiliary regenerator and the bottom of the auxiliary regenerator is 30% of the height of the auxiliary regenerator. The outlet of the auxiliary regenerator is directly connected to the bottom opening of the regenerator, and a catalyst distributor is arranged at the outlet.

[0149] The hot regenerated catalyst of the first regeneration agent pipeline 103 and the fresh catalyst of the fresh catalyst pipeline 102 enter the second reaction zone III of the first reaction section, and move upward under the lifting effect of the pre-lifting medium injected through the pre-lifting medium pipeline 101. The light distillate oil from the separation system enters the lower part of the reactor through the first feed pipeline 104 with a water-oil weight ratio of 0.2:1, and contacts and reacts with the mixed catalyst to generate an oil-agent mixture.

[0150] The hot regenerated catalyst of the first regeneration agent pipeline 103 enters the lower part of the first reaction zone I of the first reaction stage, contacts with the existing oil-agent mixture in the reactor and moves upward. The preheated crude oil and atomized steam are injected into the upstream of the first reaction zone I of the first reaction stage through the first feed pipeline 104, with a water-oil weight ratio of 0.2:1, and are mixed and contacted with the existing catalyst in the catalytic cracking reactor. The catalytic cracking reaction is carried out in the process of passing through the first reaction zone I and the second reaction zone II of the first reaction stage from bottom to top. The obtained catalyst with coke and the reaction oil gas enter the oil-agent separation device 204 such as a cyclone separator for gas-solid separation. The reaction oil gas obtained by separation is led out of the device through the gas collecting chamber 205 and the large oil and gas pipe 206, and enters the subsequent separation system; the separated catalyst with coke enters the lower part of the settler 200, and enters the auxiliary regenerator 300 through the inclined pipe 203 to be regenerated.

[0151] Nitrogen is introduced into the bottom of the auxiliary regenerator 300, mixed with the regenerated catalyst and the catalyst to be regenerated in turn and moved upward to heat the catalyst to be regenerated; the fuel oil atomized by nitrogen is injected into the auxiliary regenerator, the mass ratio of the atomizing medium to the combustion oil is 0.2:1, and contacts with the flow in the auxiliary regenerator to generate coke; the catalyst with coke enters the regenerator, contacts with the air to generate a complete combustion reaction, and the regenerated catalyst is divided into two parts, one part of the regenerated catalyst is returned to the second reaction zone III of the first reaction stage through the first regeneration agent pipeline 103 for recycling, and the other part of the regenerated catalyst is returned to the first reaction zone of the first reaction stage through the second regeneration agent pipeline 106 for recycling, and the regenerated flue gas enters the energy recovery system through pipeline 405.

[0152] At the same height of the regenerator, which is 40% of the axial height of the regenerator from the bottom, two temperature measuring points are set close to the regenerator wall (the angles of the two relative to the axial direction are 180 degrees), and the middle temperatures at different positions at the same height are measured; a temperature measuring point is set at the top of the regenerator to measure the upper temperature of the regenerator.

[0153] The operating conditions and product distribution are listed in Table 2. As can be seen from Table 2, the ethylene yield of this embodiment reaches 7.34% by weight, and the propylene yield reaches 28.64% by weight. The temperatures at different positions in the middle of the regenerator are 685°C and 680°C, respectively, with a radial temperature difference of only 5°C, and the temperature at the top of the regenerator is 693°C, with an axial temperature difference of 8-13°C.

[0154] Comparative Example 1

[0155] The crude oil and NCC catalyst shown in Table 1 were used to conduct the test on a medium-sized device. The reactor was a conventional riser reactor (first reaction stage) connected in series with a fluidized bed reactor (second reaction stage). The preheated crude oil entered the riser reaction zone and the fluidized bed reactor in turn to contact with the catalytic cracking catalyst for catalytic cracking reaction. After the reaction, the logistics entered the subsequent oil agent separation device and product separation equipment. The separated catalyst to be regenerated entered the lower part of the regenerator and contacted with the air distributed into the regenerator through the main air distributor to cause a scorching reaction. The fuel oil was injected into the catalyst dense phase bed layer. After the fuel oil contacted with the high-temperature air, a scorching reaction occurred and heat was released. The regenerated catalyst returned to the reactor for recycling. The operating conditions and product distribution are listed in Table 2.

[0156] At the same height of the regenerator, which is 40% of the axial height of the regenerator from the bottom, two temperature measuring points are set close to the regenerator wall (the angles of the two relative to the axial direction are 180 degrees), and the middle temperatures at different positions at the same height are measured; a temperature measuring point is set at the top of the regenerator to measure the upper temperature of the regenerator.

[0157] From the results in Table 2, it can be seen that the ethylene yield of the comparative example is only 5.10 wt%, and the propylene yield is only 20.43 wt%. The temperatures at different positions in the middle of the regenerator are 666°C and 724°C, respectively, with a radial temperature difference of 58°C. The temperature at the top of the regenerator is 738°C, with a large axial temperature difference.

[0158] It can be seen from the results of the above examples and comparative examples that when the catalytic cracking method and system of the present application are used for crude oil catalytic cracking reaction, the crude oil atomic utilization rate is high and the ethylene and propylene yields are significantly improved. When the heat balance is insufficient, the auxiliary regenerator is used to make the coke combustion environment in the regenerator moderate and stable, and the radial and axial catalyst temperatures are helpful to maintain the physical and chemical properties of the catalyst.

[0159] The preferred embodiments of the present application are described in detail above; however, the present application is not limited to the specific details in the above embodiments. Within the technical concept of the present application, a variety of simple modifications can be made to the technical solution of the present application, and these simple modifications all fall within the protection scope of the present application.

[0160] 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, this application will not further describe various possible combinations.

[0161] In addition, the various implementation modes of the present application may be arbitrarily combined, and as long as they do not violate the concept of the present application, they should also be regarded as the content invented by the present application.

[0162] 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.

[0163] 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.

[0164] Table 1 Properties of crude oil used

[0165]

[0166] Table 2 Comparison of reaction results between Example 1 and Comparative Example 1

[0167]

[0168]

Claims

1. A method for producing light olefins by direct catalytic cracking of crude oil, comprising: (1) A first feedstock and a regenerated catalyst from a regenerator sequentially enter a first reaction zone and a second reaction zone of a first reaction zone of a catalytic cracking reactor to undergo a catalytic cracking reaction; (2) The reaction products and the catalyst to be regenerated enter the oil separation equipment through the outlet zone for gas-solid separation. The separated reaction oil and gas are led out of the device for further separation to obtain ethylene, propylene, difficult-to-convert components and other products; (3) The separated catalyst to be regenerated is stripped and then enters the auxiliary regenerator, where it is mixed with the regenerated catalyst from the regenerator and heated, and then contacts with the coking raw material to produce a coking reaction, thereby obtaining a coking catalyst with coke; (4) the coked catalyst with coke enters the regenerator, contacts with the oxygen-containing gas to cause a complete combustion reaction of the coke to obtain a regenerated catalyst, the first part of the regenerated catalyst is returned to the first reaction zone of the first reaction stage of the catalytic cracking reactor for recycling, and the second part of the regenerated catalyst is returned to the second reaction zone of the first reaction stage at the lower part of the catalytic cracking reactor for reaction; (5) The second raw material is fed into the second reaction zone of the first reaction section of the catalytic cracking reactor, where it contacts the mixture of the regenerated catalyst and the fresh catalyst to undergo a cracking reaction. The oil-agent mixture generated by the reaction enters the first reaction zone of the first reaction section, where it is mixed with the existing stream in the first reaction zone and continues to react; Wherein, the first raw material is paraffin-based crude oil, paraffin-intermediate-based crude oil and / or intermediate-paraffin-based crude oil; The second raw material is self-produced by the device and / or other difficult-to-convert components, and the difficult-to-convert components are C4 components and / or light distillate oil with a final boiling point of less than 280-360°C.

2. The method according to claim 1, characterized in that: The C4 component includes gaseous hydrocarbons rich in C4 fraction produced by the device itself and / or other devices, wherein the content of C4 olefins in the gaseous hydrocarbons rich in C4 fraction is greater than 50% by weight; Preferably, the difficult-to-convert component is the C4 fraction produced by the device.

3. The method according to claim 1, characterized in that The difficult-to-convert components include the light distillate oil produced by the device with a final boiling point of less than 280-360° C. and one or more of the following fractions: Straight-run naphtha, straight-run kerosene, and straight-run diesel produced by other primary processing units; Other secondary processing units produce topped oil, raffinate oil, hydrocracked light naphtha, pentane oil, coker gasoline, Fischer-Tropsch synthetic oil, catalytic cracking light gasoline, hydrogenated gasoline, and hydrogenated diesel.

4. The method according to claim 1, characterized in that The reaction conditions of the first reaction zone of the first reaction section of the catalytic cracking reactor include: The reaction temperature is 550-650°C; The reaction time is 0.1-5 seconds; and / or The weight ratio of agent to oil is (5-30):1; Preferably, the first raw material enters the first reaction zone of the first reaction stage after being preheated and steam atomized, the preheating temperature is 180-350°C, and the water-oil weight ratio is (0.05-0.5):

1.

5. The method according to claim 1, characterized in that The reaction conditions of the second reaction section of the catalytic cracking reactor include: The reaction temperature is 450-600°C; and / or Weight hourly space velocity is 1-20 hours -1 .

6. The method according to claim 1, characterized in that The weight ratio of the fresh catalyst to the regenerated catalyst in the second reaction zone of the first reaction section is 0.01-0.3:

1.

7. The method according to claim 1, characterized in that The reaction conditions of the second reaction zone of the first reaction stage include: The reaction temperature is 600-720°C; Response time is 0.1-3 seconds; and / or The weight ratio of agent to oil is (5-50):1; Preferably, the second raw material is fed into the second reaction zone of the first reaction stage after being steam atomized, and the water-oil weight ratio is (0.05-0.5):

1.

8. The method according to claim 1, characterized in that The outlet temperature of the auxiliary regenerator is 550-650°C; Line speed of 1.2-2.2 m / s; and / or The coking raw material is straight-run distillate oil or secondary processed distillate oil; preferably, the secondary processed distillate oil is selected from one or more of the following: catalytic cracking diesel, catalytic cracking slurry oil, coker gasoline, coker diesel and coker wax oil.

9. A catalytic cracking system comprising: The catalytic cracking reaction unit comprises: The first reaction section comprises a first reaction zone and a second reaction zone, wherein the first reaction zone is provided with an oil agent inlet, a raw oil inlet, a first regenerated catalyst inlet and a first oil agent mixture outlet, and the second reaction zone is provided with a pre-lifting medium inlet, a second regenerated catalyst inlet, a fresh catalyst inlet, a difficult-to-convert raw material inlet and a second oil agent mixture outlet, The second oil agent mixture outlet is connected to the oil agent inlet of the first reaction zone; A second reaction section is provided with a first oil-agent mixture inlet, and the first oil-agent mixture outlet extends through the first oil-agent mixture inlet to the interior of the second reaction section; an oil agent separation device, which is provided with an oil agent inlet, a catalyst outlet and a reaction product outlet, wherein the oil agent inlet of the oil agent separation device is connected to the second reaction stage, so that the oil agent mixture from the second reaction stage is separated into reaction oil gas and catalyst to be generated by the oil agent separation device; and A settler, the settler is arranged in the second reaction section, and is used to settle and collect the catalyst to be regenerated separated by the oil agent separation device. A stripping section is arranged below the settler, and is used to strip the catalyst to be regenerated. The stripping section is provided with an outlet for the catalyst to be regenerated and an inlet for a stripping medium. A reaction product separation unit, the reaction product separation unit is connected to the oil agent separation device and is used to separate the reaction oil gas separated by the oil agent separation device; Catalyst regeneration unit, comprising: an auxiliary regenerator, used for contacting the catalyst to be regenerated separated by the catalytic cracking reaction unit with the coking raw material to generate a coking reaction to obtain a coking catalyst with coke, wherein the auxiliary regenerator is provided with an inlet for the catalyst to be regenerated, an inlet for the fluidized medium, at least one inlet for the coking raw material and an outlet for the coking catalyst, wherein the inlet for the catalyst to be regenerated is fluidically connected to the outlet for the catalyst to be regenerated of the stripping section of the settler; and A regenerator, wherein the regenerator is provided with a coke catalyst inlet, an oxygen-containing gas inlet, a gas distributor, a cyclone separator, a regenerated flue gas pipeline and at least one regenerated catalyst outlet; the raw catalyst inlet of the regenerator is fluidly connected to the coke catalyst outlet of the auxiliary regenerator; one regenerated catalyst outlet is connected to the first regenerated catalyst inlet of the first reaction zone of the first reaction stage, for recycling a part of the regenerated catalyst back to the first reaction zone of the first reaction stage; one regenerated catalyst outlet is fluidly connected to the second regenerated catalyst inlet of the second reaction zone of the first reaction stage, so that the regenerated catalyst is recycled back to the second reaction zone of the first reaction stage; A regenerated catalyst circulation pipeline connecting the auxiliary regenerator and the regenerator is arranged between the auxiliary regenerator and the regenerator, for allowing a portion of the regenerated catalyst to enter the auxiliary regenerator and mix with the catalyst to be regenerated to react with the coking raw material to form a coke.

10. The catalytic cracking system according to claim 9, characterized in that: The distance between the connection port of the external catalyst circulation pipe on the auxiliary regenerator and the bottom of the auxiliary regenerator is 5% to 10% of the height of the auxiliary regenerator; The distance between the coke raw material inlet and the bottom of the auxiliary regenerator is 20% to 50% of the height of the auxiliary regenerator.

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