High-low parallel countercurrent catalytic cracking / pyrolysis system and method

Abstract

The application provides a high-low parallel countercurrent catalytic cracking / cracking system and method, which comprises a countercurrent reactor unit, a stripping unit and a regenerator unit, the countercurrent reactor unit comprises at least two stages of reactors arranged in a cascade manner, each stage of reactors comprises a fast separation device communicated with the upper stage of reactors, and the fast separation device in the bottommost stage of reactors is correspondingly communicated with a settler, each settler is communicated with the lower stage of reactors to continuously and adjustably supply the collected catalyst into the lower stage of reactors, the bottommost stage of reactors performs a first stage of catalytic cracking / cracking reactions, the multi-stage reactors perform a step-by-step catalytic cracking / cracking reaction except the bottommost stage of reactors, and the topmost stage of reactors performs a last stage of catalytic cracking / cracking reactions. Through the system provided by the application, the flow stability of the catalyst in the reaction process is ensured, the catalytic cracking / cracking operation with high severity can be performed, and the yield of light olefins and aromatic hydrocarbons is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of catalytic cracking / cracking technology, in particular to a high-low parallel countercurrent catalytic cracking / cracking system and method. BACKGROUND

[0002] Catalytic cracking / cracking is an important industrial process in the oil refining industry. In the catalytic cracking / cracking process, high-value-added products are mostly intermediate products of consecutive chemical reactions, such as gasoline and kerosene, etc. Strictly controlling the reaction time and reducing the gas-solid back-mixing phenomenon in the reactor are beneficial to the generation of intermediate products in the reaction process. At present, most enterprises in the industry still use parallel upward fast circulating fluidized bed systems for catalytic cracking / cracking reactions. The raw oil and catalyst move from the bottom to the top of the reactor during the reaction, i.e. the movement direction of the raw oil and catalyst is in the direction of the inverse gravitational field. In this process, the catalyst is prone to downward sliding due to gravity, causing gas-solid back-mixing with the raw oil, resulting in uneven distribution of catalyst density in the axial direction of the reactor, and thus causing some catalyst to stay in the reactor for too long, leading to too long reaction time, which is not conducive to the generation of intermediate products.

[0003] Related researchers have proposed a multi-stage countercurrent catalytic cracking / cracking system, which reduces the occurrence of gas-solid back-mixing phenomenon, but the multi-stage reactors are only connected by a gas-solid rapid separation device, which requires a very high efficiency of the gas-solid rapid separation device. However, the gas-solid rapid separation device cannot always move in ideal working conditions. Once the operating conditions deviate from the ideal conditions, the separation efficiency will decrease, causing the feed amount of the next stage reactor to decrease, thus failing to ensure stable feeding of each stage reactor during the feeding process, and thus causing many adverse phenomena for catalytic cracking / cracking reactions. SUMMARY

[0004] To solve the above problems, one of the purposes of the present application is to provide a high-low parallel countercurrent catalytic cracking / cracking system to solve the problems of reduced catalyst / oil ratio, decreased reactor performance, and affected product yield and quality caused by unbalanced feeding of multi-stage reactors. The second purpose of the present application is to provide a catalytic cracking / cracking method to stably and continuously supply the required catalyst for each stage reactor, and to balance the catalyst supply demand of each stage reactor.

[0005] The first aspect of the present application provides a high-low parallel countercurrent catalytic cracking / cracking system, and the technical solution is:

[0006] A high-low parallel countercurrent catalytic cracking / pyrolysis system, comprising a countercurrent reactor unit, the countercurrent reactor unit comprising at least two stages of reactors arranged in cascade; the reactors comprising down-flow fluidized bed reactors or riser reactors, and the bottommost stage reactor being a down-flow fluidized bed reactor; wherein the outlet of each stage of the reactors is provided with a fast separation device, the gas phase outlet of the fast separation device being in communication with the gas supply port of the upper stage reactor; wherein,

[0007] The solid phase outlet of the fast separation device in each stage of the reactors, except the bottommost stage reactor, is in one-to-one correspondence with a corresponding settling vessel; wherein the settling vessel is configured to collect catalyst;

[0008] The outlet of each of the settling vessels is in communication with the solid supply port of the lower stage reactor to continuously and adjustably supply the collected catalyst to the lower stage reactor;

[0009] The bottommost stage reactor is configured to receive raw oil and carbonized catalyst, perform a first stage of catalytic cracking / pyrolysis reaction, and form transition oil gas;

[0010] Each stage of the reactors, except the bottommost stage reactor, is configured to receive the transition oil gas output by the gas phase outlet of the fast separation device at the outlet of the lower stage reactor, and receive the catalyst output by the outlet of the settling vessel in correspondence with the fast separation device at the outlet of the upper stage reactor, perform a stage-by-stage catalytic cracking / pyrolysis reaction, and form transition oil gas;

[0011] The topmost stage reactor is configured to receive transition oil gas and regenerated catalyst, perform a final stage of catalytic cracking / pyrolysis reaction, and form product oil gas.

[0012] As one of the preferred solutions, a fluidizing air ring pipe is provided in the settling vessel, which is used to fluidize the collected catalyst in the settling vessel to input the catalyst from the outlet of the settling vessel into the corresponding reactor.

[0013] As one of the preferred solutions, the system further comprises a stripping unit located downstream of the material flow of the countercurrent reactor unit; the stripping unit comprising a stripper; wherein,

[0014] The stripper is in communication with the solid phase outlet of the fast separation device at the outlet of the bottommost stage reactor of the countercurrent reactor unit;

[0015] Wherein, a steam distribution ring pipe and an internal member are provided in the stripper; the steam distribution ring pipe is used to transport stripping steam to strip the oil gas components in the catalyst by the stripping steam; the internal member, located in the internal space of the stripper above the steam distribution ring pipe, is used to increase the contact area of the catalyst with the stripping steam.

[0016] As one of the preferred solutions, the system further comprises a regenerator unit connected to the stripping unit and the countercurrent reactor unit; the regenerator unit comprises a lift regeneration pipe, a settling regeneration tank and an external circulation pipeline;

[0017] The lift regeneration pipe is in communication with the solid material outlet of the stripper to perform primary coke-burning regeneration on the catalyst stripped by the stripping unit.

[0018] The solid material outlet of the lift regeneration pipe is in communication with the middle position of the settling regeneration tank to perform deep coke-burning regeneration on the catalyst after primary coke-burning regeneration; the outlet of the settling regeneration tank is in communication with the solid material supply port of the topmost reactor of the countercurrent reactor unit to input the regenerated catalyst into the countercurrent reactor unit.

[0019] The external circulation pipeline is in communication between the settling regeneration tank and the bottom of the lift regeneration pipe, and a part of the carbon-deposited catalyst flows from the bottom of the settling regeneration tank to the bottom of the lift regeneration pipe.

[0020] As one of the preferred solutions, the lift regeneration pipe comprises a dense-phase bed pre-lift section, a dilute-phase bed conveying section and an outlet inertial separation device.

[0021] The dense-phase bed pre-lift section is used to introduce a pre-lift gas flow to partially coke-burn the carbon-deposited catalyst.

[0022] The dilute-phase bed conveying section is used to convey the carbon-deposited catalyst into the settling regeneration tank and dilute-phase burn a part of the carbon deposits of the catalyst during the conveying process, and then perform dense-phase burn on the remaining carbon deposits of the catalyst in the settling regeneration tank.

[0023] The outlet inertial separation device is located at the top end of the dilute-phase bed conveying section to perform inertial separation on the partially coke-burned catalyst.

[0024] As one of the preferred solutions, the pipe diameter of the dense-phase bed pre-lift section is greater than the pipe diameter of the dilute-phase bed conveying section, and the pipe length of the dense-phase bed pre-lift section is less than the pipe length of the dilute-phase bed conveying section, so that the catalyst forms turbulent motion in the dense-phase bed pre-lift section and is transmitted by the dilute-phase bed conveying section into the settling regeneration tank.

[0025] A vertical cyclone separator is arranged in the settling regeneration tank to separate the catalyst entrained in the flue gas after deep coke-burning regeneration.

[0026] The second aspect of the present application provides a high-low parallel countercurrent catalytic cracking / cleavage method, which is performed by the high-low parallel countercurrent catalytic cracking device system provided in the first aspect of the present application, and comprises the following steps:

[0027] The feedstock oil is introduced into the bottommost reactor of the countercurrent reactor unit, and is contacted with the catalyst carrying the coke discharged from the upper reactor to perform the first-stage catalytic cracking / cleavage reaction, and the transition oil gas is obtained after separation of the catalyst by the corresponding quick separation device;

[0028] The catalyst separated by the quick separation device at the outlet of the bottommost reactor of the multistage reactor is introduced into the corresponding settling vessel to collect the catalyst;

[0029] The transition oil gas introduced into the bottommost reactor of the multistage reactor is contacted with the catalyst continuously output from the settling vessel corresponding to the quick separation device at the outlet of the upper reactor to perform the step-by-step catalytic cracking / cleavage reaction;

[0030] The transition oil gas and the regenerated catalyst are introduced into the topmost reactor to perform the last-stage catalytic cracking / cleavage reaction, and the product oil gas is obtained after separation of the catalyst by the corresponding quick separation device.

[0031] As one of the preferred solutions, the step of introducing the catalyst separated by the quick separation device at the outlet of the bottommost reactor of the multistage reactor into the corresponding settling vessel to collect the catalyst comprises:

[0032] The catalyst separated by the quick separation device at the outlet of the bottommost reactor is introduced into the stripping unit to strip the oil gas components carried by the catalyst.

[0033] As one of the preferred solutions, the step of introducing the catalyst separated by the quick separation device at the outlet of the bottommost reactor into the stripping unit to strip the oil gas components carried by the catalyst comprises:

[0034] The stripped catalyst is input into the riser regeneration pipe to perform the primary coke-burning regeneration;

[0035] The catalyst after the primary coke-burning regeneration is input into the settling regeneration tank to perform the deep coke-burning regeneration, and the regenerated catalyst is obtained;

[0036] The regenerated catalyst is input into the topmost reactor, and is contacted with the transition oil gas introduced into the topmost reactor to perform the last-stage catalytic cracking / cleavage reaction, and the product oil gas is obtained.

[0037] As one of the preferred solutions, the method further comprises: inputting the product oil gas obtained by the reaction of the topmost reactor into a fractionating column; conveying the oil gas components carried by the catalyst carrying the coke stripped in the stripping unit to the fractionating column; separating the gas phase components and the liquid phase components in the product oil gas and the oil gas components by the fractionating column to obtain the corresponding catalytic cracking / cleavage products.

[0038] Compared with the prior art, the present application has the following advantages:

[0039] The embodiment of the present application provides a high-low parallel countercurrent catalytic cracking / cracking system, comprising a countercurrent reactor unit, the countercurrent reactor unit comprising at least two stages of reactors arranged in a cascade manner; the reactors comprising a down-flowing fluidized bed reactor or a riser reactor, and the bottommost reactor being a down-flowing fluidized bed reactor; wherein the outlet of each reactor is provided with a fast separation device, and the gas phase outlet of the fast separation device is communicated with the gas supply port of the upper-stage reactor; the solid phase outlet of the fast separation device at the outlet of the bottommost reactor is one-to-one correspondingly communicated with a settler; wherein the settler is configured to collect catalyst; the discharge port of each settler is communicated with the solid supply port of the lower-stage reactor to continuously and adjustably supply the collected catalyst into the lower-stage reactor; the bottommost reactor is configured to receive raw oil and carbonized catalyst, perform a first-stage catalytic cracking / cracking reaction, and form transition oil gas; each reactor in the multi-stage reactor is configured to receive the transition oil gas output by the gas phase outlet of the fast separation device at the outlet of the lower-stage reactor, and receive the catalyst output by the discharge port of the settler correspondingly communicated with the fast separation device at the outlet of the upper-stage reactor, perform a step-by-step catalytic cracking / cracking reaction, and form transition oil gas; and the topmost reactor is configured to receive the transition oil gas and regenerated catalyst, perform a last-stage catalytic cracking / cracking reaction, and form product oil gas.

[0040] By adopting the technical scheme of the present application, the bottommost reactor receives raw oil and catalyst to form transition oil gas, the gas supply port of each reactor receives the transition oil gas output by the gas phase outlet of the fast separation device correspondingly communicated with the lower-stage reactor, and the solid supply port receives the catalyst output by the discharge port of the settler correspondingly communicated with the solid phase outlet of the fast separation device correspondingly communicated with the upper-stage reactor, so that the multi-stage countercurrent technology is used to realize deep catalytic cracking / cracking reaction and improve the yield of low-carbon olefin products.

[0041] Since the settler can collect the catalyst output by the solid phase outlet of the correspondingly communicated fast separation device, sufficient catalyst stock can be obtained to provide a buffering and adjusting function in the feeding process, so as to cope with the flow change and operation swing of the catalyst when the fast separation device deviates from the ideal working condition. The collected catalyst helps to balance the difference between the feeding rate and the demand rate of each reactor, realizes flexible adjustment and control of the catalyst feeding, makes the transfer of the catalyst more stable and uniform, thereby ensuring continuous and stable feeding of each reactor and maintaining the pressure balance of the system, and improving the quality and yield of the products.

[0042] The embodiment of the present application can improve the circulation amount of the catalytic cracking / cleavage device system, ensure the flow stability of the catalyst in the reaction process, can perform high-severity catalytic cracking / cleavage operation, and further improve the production of light olefins and aromatic hydrocarbons.

[0043] The catalytic cracking / cleavage method provided by the embodiment of the present application has the same advantages as the high-low parallel counter-flow catalytic cracking / cleavage system described above, and will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the present application, the drawings required to be used in the description of the present application will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0045] Figure 1 is the overall schematic diagram of the high-low parallel counter-flow catalytic cracking / cleavage system described in an embodiment of the present application;

[0046] Figure 2 is the overall structural schematic diagram of the high-low parallel counter-flow catalytic cracking / cleavage system with a down-flow fluidized reactor described in an embodiment of the present application;

[0047] Figure 3 is the overall structural schematic diagram of the high-low parallel counter-flow catalytic cracking / cleavage system with a riser reactor described in an embodiment of the present application;

[0048] Figure 4 is the working principle schematic diagram of the regenerator unit described in another embodiment of the present application;

[0049] Figure 5 is the working principle flow chart of the regenerator unit described in another embodiment of the present application;

[0050] Figure 6 is the working principle flow chart of the high-low parallel counter-flow catalytic cracking / cleavage system described in another embodiment of the present application;

[0051] Figure 7 is the step flow chart of the catalytic cracking / cleavage method described in another embodiment of the present application.

[0052] BRIEF DESCRIPTION OF DRAWINGS

[0053] 1, settling regenerator; 2, topmost reactor; 3, fast separation device; 4, settler; 5, bottommost reactor; 6, stripper; 7, internals; 8, steam distribution ring; 9, lift regenerator; 10, external circulation pipeline; 11, vertical cyclone separator; 91, dense bed pre-lift section; 92, dilute bed conveying section; 93, outlet inertial separation device. DETAILED DESCRIPTION

[0054] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0055] It should be noted that, in the catalytic cracking / cleavage production process, due to various factors, such as changes in raw material properties, deviation of reaction conditions, equipment failure, operation errors and other factors, the operation condition will deviate from the ideal condition. And the gas-solid rapid separation device is used to realize the rapid separation of gas-solid two-phase, and cannot play a role in the stability and reserve of catalyst supply. Therefore, once the fast separation efficiency of the gas-solid rapid separation device decreases, it cannot meet the supply demand of the next stage reactor. Since each stage reactor is supplied by the fast separation device 3 corresponding to the upper stage reactor, it is easy to appear the problem of imbalance of feed in the coupled use of multiple reactors as mentioned in the background art, which only relies on the gas-solid rapid separation device to provide the supply source of the catalyst.

[0056] It can be known that the imbalance of catalyst supply between multiple reactors in the reaction system will cause the following adverse phenomena:

[0057] The distribution of catalysts in different stage reactors is uneven, some stage reactors may receive excessive catalysts, while other stage reactors are insufficiently supplied, resulting in differences in catalytic cracking / cleavage effect among different reactors, which will lead to inconsistent reaction effects among different reactors, affecting the conversion rate and yield of the reaction;

[0058] The uneven supply in the reaction system will cause changes in temperature and pressure, and then affect the stability and safety of the reactor.

[0059] Therefore, the embodiments of the present application provide a high-low parallel countercurrent catalytic cracking / cleavage system, Figures 1-3 respectively show an exemplary catalytic cracking / cleavage system according to some embodiments of the present disclosure, Figure 6 show the working principle flowchart of the catalytic cracking / cleavage system of the present application, wherein Figure 6The black arrows in the figure can represent the flow path of the transition oil gas, and the white arrows can represent the flow path of the catalyst. Please refer to the figure Figures 1-6 The system comprises a countercurrent reactor unit, the countercurrent reactor unit comprises at least two reactors arranged in a cascade manner; the reactors comprise down-flowing fluidized bed reactors or riser reactors, and the bottommost reactor 5 is a down-flowing fluidized bed reactor; wherein the outlet of each reactor is connected to a quick separation device 3, and the gas phase outlet of the quick separation device 3 is connected to the gas supply port of the upper reactor; wherein the solid phase outlet of the quick separation device 3 in the bottommost reactor 5 is connected to a corresponding settler 4 in the multi-stage reactor; wherein the settler 4 is configured to collect catalyst; the outlet of each settler 4 is connected to the solid supply port of the lower reactor to continuously and adjustably supply the collected catalyst to the lower reactor; the bottommost reactor 5 is configured to receive raw oil and coke catalyst, perform a first-stage catalytic cracking / cleavage reaction, and form transition oil gas; the bottommost reactor 5 in the multi-stage reactor is configured to receive the transition oil gas output by the gas phase outlet of the quick separation device 3 at the outlet of the lower reactor, and receive the catalyst output by the outlet of the settler 4 connected to the quick separation device 3 at the outlet of the upper reactor, perform a step-by-step catalytic cracking / cleavage reaction, and form transition oil gas; and the topmost reactor 2 is configured to receive transition oil gas and regenerated catalyst, perform a last-stage catalytic cracking / cleavage reaction, and form product oil gas.

[0060] Specifically, the down-flowing fluidized bed reactor is defined as a reactor in which the catalyst and the transition oil gas, or the catalyst and the raw oil, flow downward in parallel, and the down-flowing fluidized bed reactor generally comprises a turn-around head at the material inlet, a down-flowing bed body, and a quick separation device 3 at the material outlet; the riser reactor is defined as a reactor in which the catalyst and the transition oil gas, or the catalyst and the raw oil, flow upward in parallel, and the riser reactor generally comprises a pre-lifter at the material inlet, a riser body, and a quick separation device 3 at the material outlet. The bottommost reactor 5 being a down-flowing fluidized bed reactor facilitates the parallel flow of the material downward to the stripping unit located downstream of the material flow of the countercurrent reactor unit. In the embodiment, the countercurrent reactor unit can be composed of multiple down-flowing fluidized bed reactors arranged in a cascade manner (as shown in Figure 1 and Figure 2 ), or composed of multiple riser reactors arranged in a cascade manner combined with a down-flowing fluidized bed reactor at the bottommost end (as shown in Figure 3 ).

[0061] The plurality of reactors are arranged in a step-by-step manner or side by side. The bottommost reactor 5 receives raw oil and catalyst, and the raw oil and catalyst flow in parallel to perform a catalytic cracking / cleavage reaction, to obtain a gas-solid mixture of transition oil gas and catalyst. Each reactor except the bottommost reactor 5 receives the transition oil gas and catalyst, and the transition oil gas and catalyst flow in parallel to perform a catalytic cracking / cleavage reaction, to obtain a gas-solid mixture of transition oil gas and catalyst. In this embodiment, the raw oil can refer to crude oil and natural gas, etc. to be processed. The transition oil gas can refer to a mixture of gas phase and liquid phase formed in the reactor, including unreacted raw material substances, conversion products, intermediate products, and other substances generated during the reaction, such as hydrocarbon compounds, non-hydrocarbon gases, and diesel, gasoline, liquefied petroleum gas, and coke, etc.

[0062] It should be understood that the specific components and proportions of the transition oil gas will change in the reactor as the reaction proceeds, and are also affected by the reaction conditions and catalysts. Therefore, the transition oil gas in each reactor is of the same nature but different states, or in other words, the content of product components in the transition oil gas in each fluidized bed reactor increases and the degree of carbon deposition of the catalyst increases from the topmost reactor 2 to the bottommost reactor 5 in the multi-stage reactor.

[0063] Therefore, the bottommost reactor 5 receives raw oil and catalyst, and after contacting with the catalyst that has deposited carbon, performs a first-stage catalytic cracking reaction and forms a transition oil gas product; the topmost reactor 2 serves as a product oil gas generation unit, and the transition oil gas performs a last-stage catalytic cracking / cleavage reaction with regenerated catalyst to form a product oil gas and deliver it to a fractionating column.

[0064] In this embodiment, the quick separation device 3 located at the material outlet of the reactor is defined as a device that can separate the transition oil gas and the catalyst. The transition oil gas and the catalyst generated by the reaction of each reactor are input into the corresponding quick separation device 3. The gas phase outlet of the corresponding quick separation device 3 of each reactor is in communication with the gas inlet of the corresponding upper-stage reactor, so as to input the separated transition oil gas into the upper-stage reactor. The solid phase outlet of the corresponding quick separation device 3 of each reactor is in communication with the inlet of the corresponding settler 4, and the outlet of each settler 4 is in communication with the solid supply inlet of the corresponding lower-stage reactor, so as to input the separated catalyst into the lower-stage reactor. This makes the transition oil gas transported from the bottommost reactor 5 to the corresponding upper-stage reactor, and the catalyst transported from the topmost reactor 2 to the corresponding lower-stage reactor, so that the transition oil gas and the catalyst perform countercurrent contact, and the depth of the catalytic cracking / cleavage reaction is realized by using the multi-stage countercurrent technology, and the yield of low-carbon olefin products is improved.

[0065] In the present embodiment, a settling tank 4 is arranged between two adjacent reactors; the settling tank 4 is arranged to collect the catalyst output from the solid phase outlet of the fast separation device 3, to provide a certain storage amount during the catalyst feeding process, to form a buffer storage amount, to provide the function of buffering and adjusting during the feeding process. The outlet of each settling tank 4 is in communication with the solid feeding port of the next stage reactor, and the collected catalyst can be continuously supplied to the corresponding next stage reactor in a controllable manner. Due to the existence of the buffer storage amount, under the condition that the fast separation efficiency of the fast separation device 3 is reduced, the catalyst flow is changed, or other operation fluctuations, the difference between the feeding rate and the demand rate of the next stage reactor can be balanced by the buffer storage amount, to maintain the stable and balanced feeding of each stage reactor except the bottommost reactor 5.

[0066] Specifically, the outlet of each settling tank 4 is in communication with the solid feeding port of the next stage reactor, the opening of the valve at the outlet of the settling tank 4 can be controlled to adjust the feeding rate of the catalyst, when the demand rate of the next stage reactor is low, the catalyst can accumulate in the settling tank 4 to maintain a certain storage amount, when the demand rate increases, the storage amount in the settling tank 4 can be released to meet the feeding demand of each stage reactor.

[0067] Illustratively, when the fast separation efficiency is reduced, the supply amount of the catalyst can be insufficient, at this time the demand rate increases, by adjusting the storage amount in the settling tank, additional catalyst supply can be provided to make up for the decrease in the feeding amount. Therefore, even if the feeding amount of the next stage reactor is reduced due to the reduction of the fast separation efficiency of the fast separation device 3, the settling tank 4 can always provide stable catalyst supply to ensure the stable and balanced feeding of each stage reactor except the bottommost reactor 5, thereby solving the imbalance of catalyst feeding between the multi-stage reactors and the adverse phenomena that may occur.

[0068] Wherein, the buffer storage amount of the catalyst can affect the gas flow and pressure distribution, by adjusting the buffer storage amount, the pressure distribution inside the system can be adjusted to maintain the pressure balance between the reactors, thereby improving the stability of the system.

[0069] It can be understood that the topmost reactor 2 to the bottommost reactor 5 in the multi-stage reactor of the present application are defined according to the sequence of the flow path of the catalyst. Among them, the catalyst in the topmost reactor 2 cannot be input from the upper stage reactor, which can be directly input into the topmost reactor 2, or input into the topmost reactor 2 by the regenerator unit; the catalyst in the bottommost reactor 5 does not need to be input to the next stage reactor, that is, there is no need to balance the difference between the feeding rate and the demand rate of the next stage reactor, therefore the solid phase outlet of the fast separation device 3 at the outlet of the bottommost reactor 5 does not need to be additionally provided with a settling tank 4.

[0070] AsFigures 1-3 The system with two-stage reactors is shown, wherein the topmost reactor 2 and the bottommost reactor 5 are respectively shown.

[0071] The embodiment is used to further illustrate the settler 4. The settler 4 is provided with a fluidizing air ring pipe for fluidizing the catalyst collected in the settler 4 to input the catalyst from the discharge port of the settler 4 into the corresponding reactor.

[0072] Specifically, the settler 4 can include a tank body with a volume to form a buffer zone that can accommodate a buffer storage amount of a certain material level height, which generally has a bottom outlet and a top outlet. When the catalyst enters the settling tank, it will gradually settle to the bottom due to gravity to form a certain material level height. The catalyst can be stably stored in the buffer zone, and the opening degree of the valve at the bottom outlet of the settling tank can be controlled to adjust the catalyst supply rate as a continuous, stable and adjustable supply source for the next stage or the bottommost reactor 5.

[0073] The fluidizing air ring pipe is located inside the settling tank and has a ring pipe structure. The fluidizing air ring pipe can be connected to introduce fluidizing air to generate a proper air flow speed and pressure, and the fluidizing air is input into the tank body through a plurality of air holes on the fluidizing air ring pipe to loosen and fluidize the catalyst collected in the tank body by providing a proper air flow speed to ensure that the catalyst can smoothly enter the next stage reactor.

[0074] It should be further noted that in the related art, in addition to the problems mentioned in the background art, the settler regeneration tank 1 is connected to the reactor through the lifting regeneration pipe 9, which requires additional introduction of lifting air, resulting in a large air consumption of the system.

[0075] Another object of the present application is to solve the problem of large air consumption in the catalyst regeneration and circulation process. A new embodiment is proposed, and the present application achieves the object by the following technical measures:

[0076] The system further comprises:

[0077] A stripping unit located downstream of the material flow of the countercurrent reactor unit; the stripping unit comprises a stripper 6; wherein the stripper 6 is in communication with the solid phase outlet of the fast separation device 3 at the outlet of the bottommost reactor 5 of the countercurrent reactor unit; wherein the stripper 6 is provided with a steam distribution ring pipe 8 and an inner member 7; the steam distribution ring pipe 8 is used to transport stripping steam to strip the oil gas components in the catalyst; the inner member 7 is located in the internal space of the stripper 6 above the steam distribution ring pipe 8 to increase the contact area of the catalyst and the stripping steam.

[0078] Specifically, in this embodiment, after the catalytic cracking / cleavage reaction, the catalyst can carry oil and gas components generated during the reaction, which are usually in the form of adsorption or adhesion on the surface of the catalyst particles. The oil and gas components can be incompletely reacted or incompletely separated reaction products, such as volatile hydrocarbons or hydrocarbon substances generated during the reaction. By transporting the catalyst at the solid phase outlet of the quick separation device 3 at the outlet of the bottommost reactor 5 into the stripper 6, the stripper 6 can be used to evaporate and separate the oil and gas components in the catalyst, which are released in the form of gas or steam.

[0079] It can be understood that the stripper 6 has a shell for accommodating internal components and processing fluids. The shell is usually a closed container with appropriate solid material inlets and solid material outlets, which can be in communication with the solid phase outlet of the quick separation device 3 at the outlet of the bottommost reactor 5 and the inlet of the subsequent regenerator unit. The internal components can include a steam distribution ring pipe 8 and an inner member 7.

[0080] The steam distribution ring pipe 8 is located at the bottom of the stripper 6 and is a ring pipe system. The stripping steam enters the stripper 6 through the steam distribution ring pipe 8 and is uniformly distributed to the catalyst bed through the steam distribution ring pipe 8. The steam is fully fluidized with a certain steam injection angle and nozzle structure to the oil and gas containing catalyst particles, so as to contact and act with the catalyst entering the stripper 6, and realize the processes of mass transfer and heat transfer. When the stripping steam contacts the catalyst, heat is released, which causes the oil and gas components in the catalyst to evaporate and separate. Subsequently, the stripping steam and the volatiles rise together, thereby realizing the extraction and recovery of the oil and gas components in the oil and gas containing catalyst particles.

[0081] Specifically, when the stripping steam enters the catalyst bed through the steam distribution ring pipe 8 at the bottom of the stripper 6, the catalyst particles rise with the stripping steam. The inner member 7 is arranged above the steam distribution ring pipe 8, which guides the flow of gas during the rising of the catalyst particles, and increases the contact area between the catalyst particles and the steam. The increased contact area allows the catalyst particles to be more fully exposed to the stripping steam, thereby realizing the effects of heat transfer and mass transfer.

[0082] The inner member 7 is triangular and is arranged in a stacked manner at different heights along the axial direction of the stripper 6. The arrangement of multiple triangular inner members 7 at different bed material heights can form multiple levels of material distribution. Through the arrangement of the inner member 7, the catalyst particles sink with the rising of the gas flow, and the catalyst particles form surges and mix at different height positions, thereby increasing the contact area between the catalyst and the stripping steam, and helping to promote the mass transfer and reaction process between the catalyst particles and the stripping steam, and improving the reaction efficiency.

[0083] Referring to Figure 4 and Figure 5 as shown, Figure 4 The structure mechanism of the exemplary settling regenerator 1 and the lift regeneration pipe 9 according to some embodiments of the present disclosure is shown. Figure 5 The working mechanism of the exemplary settling regenerator 1 and the lift regeneration pipe 9 according to some embodiments of the present disclosure is shown. In further technical solutions,

[0084] The system further comprises:

[0085] A regenerator unit connecting the stripping unit and the reverse flow reactor unit; the regenerator unit comprises a lift regeneration pipe 9, a settling regenerator 1 and an external circulation pipeline 10; wherein the lift regeneration pipe 9 is in communication with the solid material outlet of the stripper 6 to perform primary coke-burning regeneration on the carbon deposition catalyst after stripping of the catalyst entrained oil gas by the stripping unit; wherein the solid material outlet of the lift regeneration pipe 9 is in communication with the middle position of the settling regenerator 1 to perform deep coke-burning regeneration on the catalyst after primary coke-burning regeneration; the outlet of the settling regenerator 1 is in communication with the solid material supply port of the topmost reactor 2 of the reverse flow reactor unit to input the regenerated catalyst into the reverse flow reactor unit; wherein the external circulation pipeline 10 connects the bottom of the settling regenerator 1 and the lift regeneration pipe 9, and a part of the catalyst flows from the bottom of the settling regenerator 1 to the bottom of the lift regeneration pipe 9.

[0086] Specifically, the catalyst at the solid material outlet of the stripper 6 in the prior art first flows to the settling regenerator 1, then to the lift regeneration pipe 9, and then to the solid material supply port of the topmost reactor 2, and the carbon deposition substances have been removed in the settling regenerator 1, in this way, the lift regeneration pipe 9 needs to additionally use the lift gas flow and is only used for the transportation of the catalyst.

[0087] In the present application, the catalyst at the solid material outlet of the stripper 6 first flows to the lift regeneration pipe 9, and then to the settling regenerator 1, part of the carbon deposition substances have been burned in the lift regeneration pipe 9 to realize primary coke-burning regeneration, and the remaining part of the carbon deposition substances enter the settling regenerator 1 to realize deep coke-burning regeneration. In the regeneration mode of the present application, the lift regeneration pipe 9 plays multiple roles in the catalytic cracking / cracking system, it is not only used for the transportation of the catalyst, the lift gas flow participates in the partial combustion and regeneration process of the carbon deposition substances, realizes the efficient regeneration cycle of the catalyst, reduces the energy consumption of the system, and utilizes the lift air volume to ensure the effective operation of the settling regenerator 1.

[0088] The solid material outlet of the lifting regeneration pipe 9 is communicated with the middle part of the settling regeneration tank 1, and a dense-phase fluidized bed with a certain bed height is formed in the tank body to perform deep coke-burning regeneration on the catalyst regenerated by the primary coke-burning regeneration; the outlet of the settling regeneration tank 1 is communicated with the solid material supply port of the top reactor 2 of the countercurrent reactor unit, and the regenerated catalyst after deep coke-burning regeneration can be input into the top reactor 2 of the countercurrent reactor unit.

[0089] The outer circulation pipeline 10 is communicated with the bottom of the lifting regeneration pipe 9 and the settling regeneration tank 1, and a part of the carbonized catalyst flows from the bottom of the settling regeneration tank 1 to the bottom of the lifting regeneration pipe 9, so as to improve the coke-burning intensity of the whole device system and realize the heat balance of the regenerator unit.

[0090] In the embodiment, the lifting gas flow can refer to air or oxygen-rich gas introduced from the outside through the bottom of the lifting regeneration pipe 9, which is used to push the catalyst to move upward in the lifting regeneration pipe 9 and be transported to the settling regeneration tank 1. During the transportation, the lifting gas flow can be partially combusted with the carbonized substances to promote the oxidation and desorption of the carbonized substances and reduce the accumulation of carbon on the surface of the catalyst.

[0091] It needs to be explained that the catalyst in the lifting regeneration pipe 9 is mixed with the lifting gas flow, and partial combustion and regeneration reactions occur therein. Compared with the settling regeneration tank 1, the function and scale of the lifting regeneration pipe 9 are limited and are not sufficient to complete the complete regeneration process, and the regeneration gas in the lifting regeneration pipe 9 does not need to be discharged and can flow to the settling regeneration tank 1 together with the catalyst, so that the input requirement of the regeneration gas in the settling regeneration tank 1 is relatively small. Therefore, the settling regeneration tank 1 does not need to additionally input a large amount of regeneration gas. In some embodiments, the lifting gas flow introduced by the lifting regeneration pipe 9 is sufficient to provide the gas required for regeneration, and the lifting gas flow can be used as the regeneration gas, and the settling regeneration tank 1 does not need to additionally input the regeneration gas. In this way, the embodiment of the present application can reduce the consumption of system air volume and the use of energy and reduce the cost.

[0092] The catalyst entering the settling regeneration tank 1 has a deep regeneration function, and the remaining carbonized substances are subjected to dense-phase combustion. The regeneration gas and / or the lifting gas flow enter the bed layer of the settling regeneration tank 1 and contact the carbonized catalyst particles. At high temperature, the regeneration gas and / or the lifting gas flow are subjected to dense-phase combustion with the carbonized substances, and the carbonized substances are converted into harmless substances such as carbon dioxide and water vapor, so as to remove the carbonized substances from the surface of the catalyst. After the regeneration reaction, the remaining gas and products are discharged from the settling regeneration tank 1 to the flue gas turbine.

[0093] In some embodiments, the lift regeneration pipe 9 comprises a dense phase bed pre-lift section 91, a dilute phase bed transport section 92 and an outlet inertial separation device 93; the dense phase bed pre-lift section 91 is used to introduce a pre-lift gas flow to partially coke the catalyst with carbon deposition; the dilute phase bed transport section 92 is used to transport the catalyst with carbon deposition to the settling regeneration tank 1 and to burn part of the carbon deposition of the catalyst with carbon deposition in a dilute phase during the transport, and then to burn the remaining carbon deposition of the catalyst in a dense phase in the settling regeneration tank 1; the outlet inertial separation device 93 is located at the top end of the dilute phase bed transport section 92 and is used to inertially separate the partially coked catalyst.

[0094] Further, the pipe diameter of the dense phase bed pre-lift section 91 is greater than the pipe diameter of the dilute phase bed transport section 92, and the pipe length of the dense phase bed pre-lift section 91 is less than the pipe length of the dilute phase bed transport section 92, so that the catalyst forms a turbulent motion in the dense phase bed pre-lift section 91 and is transported by the dilute phase bed transport section 92 into the settling regeneration tank; a vertical cyclone 11 is arranged in the settling regeneration tank to separate the catalyst entrained in the flue gas after deep coking regeneration.

[0095] Specifically, the dense phase bed pre-lift section 91 forms a turbulent flow zone, and the dilute phase bed transport section 92 forms a transport zone; the pipe diameter of the dense phase bed pre-lift section 91 is greater than the pipe diameter of the dilute phase bed transport section 92, and the gas velocity in the dense phase bed pre-lift section 91 is less than the gas velocity in the dilute phase bed transport section 92, which promotes more lift gas flow to participate in turbulent motion in the turbulent flow zone, and the turbulent motion in the turbulent flow bed can improve the degree of gas-solid contact and the uniformity of mixing to improve the combustion efficiency of the lift. In the transport zone, due to the small inner diameter of the bed and the large gas velocity, the flow velocity of the gas-solid mixture is fast, and the catalyst flows at high speed with the lift gas flow, reducing the contact time between the lift gas flow and the catalyst. Therefore, the residence time of the catalyst in the transport zone can be effectively reduced, the gas-solid backmixing phenomenon can be reduced, and most of the catalyst can be quickly transported from the turbulent flow zone to the settling regeneration tank 1 for complete regeneration treatment. The outlet inertial separation device 93 is located at the top end of the dilute phase bed transport section 92 and is used to inertially separate the partially coked catalyst particles, avoiding excessive catalyst particles from being entrained by the flue gas and effectively settling in the settling regeneration tank 1.

[0096] Please refer again to Figure 4The design of the lift regeneration pipe 9 is improved, and the catalyst output from the stripper 6 firstly enters the dense phase bed pre-lift section 91 for pre-coking, in the dense phase bed pre-lift section 91, the diffusion rate of the catalyst and the pre-lift gas flow is accelerated, and the catalyst is quickly sent to the dilute phase bed conveying section 92 for coking, and the dilute phase bed conveying section 92 is small in inner diameter and high in gas speed, so that the catalyst is smoothly conveyed from the dense phase bed pre-lift section 91 to the settling regeneration tank 1, the residence time and back mixing of the catalyst are reduced, the partial carbon deposition of the catalyst is burned in the dilute phase, and the carbon deposition content in the catalyst is reduced.

[0097] The catalyst output from the dilute phase bed conveying section 92 enters the settling regeneration tank 1 for dense phase combustion, realizes deep coking regeneration of the catalyst, and separates the catalyst entrained in the flue gas after deep coking regeneration through the vertical cyclone separator 11, so that too many catalyst particles are not entrained by the flue gas and effectively settled in the settling regeneration tank 1.

[0098] Preferably, the lift regeneration pipe 9 is in communication with the settling regeneration tank 1 through the external circulation pipeline 10. In this embodiment, a catalyst outlet is arranged on the lower part of the side wall of the settling regeneration tank 1, a catalyst inlet is arranged on the lower part of the side wall of the lift regeneration pipe 9, and the external circulation pipeline 10 is inserted into the two catalyst outlets and the catalyst inlet, so that the coking intensity of the whole device system is improved, and the heat balance of the regenerator unit is realized.

[0099] It should be explained that the reactor, the fast separation device 3, the settler 4, the stripper 6, the lift regeneration pipe 9 and the settling regeneration tank 1 in the system of the present application all belong to devices with known functions, and for the sake of clarity and simplicity, part of the description of the corresponding devices is omitted, and the other parts not described in detail can be referred to the prior art with the functions described in the present application.

[0100] The present application also provides a catalytic cracking / cracking method, Figure 7 The step flow chart of the catalytic cracking / cracking method of the present application is shown, which is realized by relying on the high-low parallel catalytic cracking / cracking system as described above, and the method comprises the following steps:

[0101] S1, the raw oil is introduced into the bottommost reactor 5 in the countercurrent reactor unit to contact with the catalyst with carbon deposition output from the upper reactor for first-stage catalytic cracking / cracking reaction, and the transition oil gas is obtained after the catalyst is separated through the corresponding fast separation device 3;

[0102] S2, the catalyst separated by the fast separation device 3 at the outlet of the bottommost reactor 5 in the multi-stage reactor is introduced into the corresponding connected settler 4 for catalyst collection;

[0103] S3, the transition oil gas separated by the fast separation device 3 at the outlet of the next stage reactor is introduced into the multi-stage reactor, and the catalyst continuously output by the settler 4 corresponding to the fast separation device 3 at the outlet of the previous stage reactor is contacted to carry out the catalytic cracking / cleavage reaction stage by stage;

[0104] S4, the transition oil gas and regenerated catalyst are introduced into the topmost reactor 2 to carry out the last stage of catalytic cracking / cleavage reaction, and the product oil gas is separated after the catalyst is separated by the corresponding fast separation device 3.

[0105] In the embodiment, the raw oil is subjected to catalytic cracking / cleavage reaction under the action of the catalyst by using the countercurrent reactor unit, the generated transition oil gas flows into the fractionating column, and the catalyst containing oil gas carbon is introduced into the stripping unit after the catalytic cracking reaction is completed. The water vapor of the stripper 6 is uniformly fluidized and contacted with the catalyst containing oil gas carbon to remove the oil gas adsorbed on the carbonized catalyst and replace the oil gas between the catalyst particles, and the oil gas is further introduced into the fractionating column for separation; the carbonized catalyst after stripping is the spent catalyst, which is further introduced into the regenerator unit. The spent catalyst is coked and regenerated by using the regenerator unit, and the spent catalyst is subjected to dilute phase combustion and dense phase combustion in the regenerator unit in sequence to form regenerated catalyst, which is further introduced into the topmost reactor 2 in the countercurrent reactor unit.

[0106] The transition oil gas mixture is reacted in the countercurrent reactor unit along the downflowing fluidized bed reactor or the riser reactor of each stage from the bottommost reactor 5 to the topmost reactor 2, and then is contacted with the regenerated catalyst transported from the regenerator unit to carry out the last stage of catalytic cracking / cleavage reaction to form the final oil gas product.

[0107] A slide valve is arranged on the feed pipe of each reactor in the countercurrent reactor unit, and the opening size of the slide valve is adjusted during operation to accurately control the catalyst circulation amount and the catalyst / oil ratio in the reaction process. The catalyst separated by the fast separation device 3 at the outlet of the bottommost reactor 5 in the multi-stage reactor is introduced into the settler 4 corresponding to each fast separation device 3 for catalyst collection. The settler 4 in the countercurrent reactor unit must always maintain a certain material level during operation, and the sufficient amount of catalyst in the settler 4 ensures the stability of the reactor feed and widens the operation interval of the catalyst circulation amount in the reactor.

[0108] Further, step S2 comprises:

[0109] S5, the catalyst separated by the fast separation device 3 at the outlet of the bottommost reactor 5 is introduced into the stripping unit to strip the oil gas components carried by the catalyst.

[0110] Further, step S5 is followed by:

[0111] S6, inputting the stripped catalyst into the riser regeneration pipe 9 for primary coke-burning regeneration;

[0112] S7, inputting the primary coke-burning regenerated catalyst into the settling regeneration tank 1 for deep coke-burning regeneration, to obtain regenerated catalyst;

[0113] S8, inputting the regenerated catalyst into the topmost reactor 2, and contacting with the transition oil gas introduced into the topmost reactor 2, to perform the last stage of catalytic cracking / cleavage reaction, to obtain product oil gas.

[0114] Further, step S8 is followed by:

[0115] S9, inputting the product oil gas obtained from the reaction of the topmost reactor 2 into the fractionating column;

[0116] Step S5 is followed by:

[0117] S10, transporting the oil gas components carried by the carbonized catalyst stripped in the stripping unit to the fractionating column;

[0118] Step S9 and step S10 are followed by:

[0119] S11, separating the gas phase components and liquid phase components in the product oil gas and the oil gas components by using the fractionating column, to obtain corresponding catalytic cracking / cleavage products.

[0120] It can be understood that the above steps S1-S11 are not strictly in sequence, and some steps can be performed simultaneously, or some steps with later serial numbers can be performed before steps with earlier serial numbers.

[0121] In the method embodiment provided by the present application, the catalyst can be a molecular sieve with a particle size of 20-100 μm; and / or, the temperature of the catalytic cracking / cleavage reaction is 550-700 ℃. Specifically, the molecular sieve can be a main agent with Y-type molecular sieve as the main body and an auxiliary agent with ZSM-5 as the main body, and the mass ratio of the main agent to the auxiliary agent is 1.5:1-8:1, and / or the specific surface area of the special-purpose catalyst composed of the main agent and the auxiliary agent is 600-800 m 2 / / g. 2 / g.

[0122] The following describes a catalytic cracking / cleavage method of the present application by taking a three-stage reactor as an example:

[0123] S101, the molecular sieve with a particle size of 25 μm is introduced into the first stage reactor, the raw oil is introduced into the third stage reactor, the molecular sieve flows from the outlet of the first stage reactor to the third stage reactor via the second stage reactor and is mixed with the raw oil, the temperature in the third stage reactor is controlled to be 550-650 ℃, the catalytic cracking / cracking reaction is carried out for a period of time, and the transition oil gas is obtained;

[0124] S102, the transition oil gas and the catalyst are introduced into the second stage reactor to mix the raw oil and the catalyst, the temperature in the second stage reactor is controlled to be 650-700 ℃, the catalytic cracking / cracking reaction is carried out for a period of time; the transition oil gas is introduced into the first stage reactor to mix with the catalyst inside, the temperature in the first stage reactor is controlled to be 550-650 ℃, the catalytic cracking / cracking reaction is carried out for a period of time, and the product oil gas is obtained;

[0125] S103, the product oil gas and the transition oil gas obtained by the catalytic cracking / cracking reaction of the first stage reactor, the second stage reactor and the third stage reactor, and the catalyst participating in the catalytic cracking / cracking reaction are respectively input to the corresponding fast separation device 3 for gas-solid separation, and the catalyst after the catalytic cracking / cracking reaction of each stage reactor and the transition oil gas or the product oil gas are obtained;

[0126] S104, the transition oil gas after reaction in the third stage reactor is introduced into the second stage reactor, the catalyst after reaction in the third stage reactor is introduced into the stripper 6, the oil gas components carried by the catalyst are evaporated, and the evaporated oil gas components are introduced into the fractionating column; the transition oil gas after reaction in the second stage reactor is introduced into the first stage reactor, the catalyst after reaction in the second stage reactor is introduced into the settler 4; the product oil gas after reaction in the first stage reactor is introduced into the fractionating column, and the catalyst after reaction in the first stage reactor is introduced into the settler 4;

[0127] S105, the catalyst after reaction in the second stage reactor is continuously and adjustably input into the third stage reactor by the settler 4; the catalyst after reaction in the first stage reactor is adjustably input into the second stage reactor by the settler 4;

[0128] S106, the catalyst after evaporation of the oil gas components by the stripper 6 is input into the settling regeneration tank 1 after primary coke-burning regeneration by the lifting regeneration pipe 9 for deep coke-burning regeneration, forming regenerated catalyst, and the regenerated catalyst flows into the first stage reactor;

[0129] S107, separating the gas phase component and the liquid phase component in the product oil gas and the oil gas component input in step S104 by using a fractionating column, and outputting the separated gas phase component and the liquid phase component respectively, to obtain hydrogen, methane, ethane, ethylene, propane, propylene, n-butane, iso-butane, iso-butene, butene, gasoline, diesel, heavy oil, coke and the like.

[0130] It should be noted that each of the embodiments in the specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the embodiments can be referred to each other.

[0131] It should also be noted that in this document, the terms "upper", "lower", "left", "right", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the application and simplify the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application. In addition, relationship terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations, nor can it be understood as indicating or implying relative importance. Moreover, the term "comprise" or any other variation thereof is intended to cover non-exclusive inclusion, so that the process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed or inherent to such process, method, article or terminal device.

[0132] The above provides a high-low parallel countercurrent catalytic cracking / cleavage system and method, and the principles and implementation modes of the application are described by specific examples. The above embodiment description is only used to help understand the application, and the content of the specification should not be understood as a limitation on the application. Meanwhile, for those skilled in the art, according to the application, there will be different forms of changes in specific implementation modes and application ranges, which do not need and cannot be exhaustively enumerated here, and the obvious changes or variations derived therefrom are still within the protection scope of the application.

Claims

1. A high-low parallel countercurrent catalytic cracking / pyrolysis system characterized in that, The system comprises a countercurrent reactor unit, which comprises at least two reactors arranged in a cascade manner; the reactors comprise down-flow fluidized bed reactors or riser reactors, and the bottommost reactor is a down-flow fluidized bed reactor; wherein, The outlet of each reactor is provided with a fast separation device, and the gas phase outlet of the fast separation device is communicated with the gas supply port of the upper reactor; The solid phase outlet of the fast separation device in the bottommost reactor is communicated with a corresponding settler in the countercurrent reactor unit; wherein, the settler is configured to collect catalysts; The settler is configured to collect catalysts; The outlet of each settler is communicated with the solid supply port of the lower reactor to continuously and adjustably supply the collected catalysts to the lower reactor; The bottommost reactor is configured to receive raw oil and carbonized catalysts, perform a first-stage catalytic cracking / cleavage reaction, and form transition oil gas; The bottommost reactor is configured to receive the transition oil gas output by the gas phase outlet of the fast separation device at the outlet of the lower reactor, and receive the catalysts output by the outlet of the settler corresponding to the fast separation device at the outlet of the upper reactor, perform a step-by-step catalytic cracking / cleavage reaction, and form transition oil gas; The topmost reactor is configured to receive transition oil gas and regenerated catalysts, perform a last-stage catalytic cracking / cleavage reaction, and form product oil gas, 2. A high-low parallel countercurrent catalytic cracking / pyrolysis system according to claim 1, wherein The settler is provided with a fluidizing air ring pipe for fluidizing the collected catalysts in the settler to input the catalysts from the outlet of the settler into the corresponding reactor. The system further comprises a stripping unit downstream of the material flow of the countercurrent reactor unit; the stripping unit comprises a stripper; wherein, The stripper is communicated with the solid phase outlet of the fast separation device at the outlet of the bottommost reactor of the countercurrent reactor unit; 3. A high-low parallel countercurrent catalytic cracking / pyrolysis system according to claim 2, wherein The stripper is provided with a steam distribution ring pipe and an internal member; the steam distribution ring pipe is used to transport stripping steam to strip oil gas components in the catalyst by the stripping steam; the internal member is located in the internal space of the stripper above the steam distribution ring pipe to increase the contact area of the catalyst and the stripping steam. The system further comprises a regenerator unit connected to the stripping unit and the countercurrent reactor unit; the regenerator unit comprises a lifting regeneration pipe, a settling regeneration tank, and an external circulation pipeline; The lifting regeneration pipe is communicated with the solid outlet of the stripper to perform primary coke-burning regeneration on the catalyst stripped by the stripper; The solid outlet of the lifting regeneration pipe is communicated at the middle position of the settling regeneration tank to perform deep coke-burning regeneration on the catalyst after primary coke-burning regeneration; The outlet of the settling regeneration tank is communicated with the solid supply port of the topmost reactor of the countercurrent reactor unit to input the regenerated catalyst into the topmost reactor; The external circulation pipeline communicates the settling regeneration tank with the bottom of the lifting regeneration pipe, and a part of the carbonized catalysts flow from the bottom of the settling regeneration tank to the bottom of the lifting regeneration pipe.

4. A high-low parallel countercurrent catalytic cracking / pyrolysis system according to claim 3 wherein, The lifting regeneration pipe comprises a dense phase bed pre-lifting section, a dilute phase bed conveying section and an outlet inertial separation device; The dense phase bed pre-lifting section is used for introducing a pre-lifting gas flow to partially coke the catalyst with coke; The dilute phase bed conveying section is used for conveying the catalyst with coke to the settling regeneration tank and performing dilute phase combustion on part of the coke of the catalyst during the conveying process, and then performing dense phase combustion on the remaining coke of the catalyst in the settling regeneration tank; The outlet inertial separation device is located at the top end of the dilute phase bed conveying section and is used for performing inertial separation on the partially-cooked catalyst.

5. A high-low parallel countercurrent catalytic cracking / pyrolysis system according to claim 4 wherein, The pipe diameter of the dense phase bed pre-lifting section is greater than the pipe diameter of the dilute phase bed conveying section, and the pipe length of the dense phase bed pre-lifting section is less than the pipe length of the dilute phase bed conveying section, so that the catalyst forms turbulent motion in the dense phase bed pre-lifting section and is transmitted to the settling regeneration tank by the dilute phase bed conveying section; A vertical cyclone separator is arranged in the settling regeneration tank to separate the catalyst entrained in the flue gas after deep coke-burning regeneration.

6. A high-low parallel counter-current catalytic cracking / pyrolysis process characterized by, The high-low parallel countercurrent catalytic cracking device system based on any one of claims 1 to 5 performs catalytic cracking / cracking, comprising the following steps: The raw oil is introduced into the bottommost reactor in the countercurrent reactor unit to contact with the catalyst with coke output from the upper reactor to perform the first-stage catalytic cracking / cracking reaction, and the catalyst is separated by the corresponding quick separation device to obtain transition oil gas; The catalyst separated by the quick separation device at the outlet of the bottommost reactor in the multi-stage reactor is introduced into the corresponding settling tank to collect the catalyst; The transition oil gas separated by the quick separation device at the outlet of the bottommost reactor in the multi-stage reactor is introduced into the bottommost reactor to contact with the catalyst continuously output from the settling tank corresponding to the quick separation device at the outlet of the upper reactor to perform the step-by-step catalytic cracking / cracking reaction; The transition oil gas and regenerated catalyst are introduced into the topmost reactor to perform the last-stage catalytic cracking / cracking reaction, and the catalyst is separated by the corresponding quick separation device to obtain product oil gas.

7. A high-low parallel countercurrent catalytic cracking / pyrolysis process according to claim 6 wherein, The step of introducing the catalyst separated by the quick separation device at the outlet of the bottommost reactor into the corresponding settling tank to collect the catalyst comprises: The catalyst separated by the quick separation device at the outlet of the bottommost reactor is introduced into the stripping unit to strip the oil gas components carried by the catalyst.

8. A high-low parallel countercurrent catalytic cracking / pyrolysis process according to claim 7, characterized in that, The step of introducing the catalyst separated by the quick separation device at the outlet of the bottommost reactor into the stripping unit to strip the oil gas components carried by the catalyst comprises: The stripped catalyst is input into the lifting regeneration pipe to perform primary coke-burning regeneration; The catalyst after primary coke-burning regeneration is input into the settling regeneration tank to perform deep coke-burning regeneration to obtain regenerated catalyst; The regenerated catalyst is input into the topmost reactor to contact with the transition oil gas introduced into the topmost reactor to perform the last-stage catalytic cracking / cracking reaction to obtain product oil gas.

9. A high-low parallel countercurrent catalytic cracking / pyrolysis process according to claim 8, characterized in that, The method further comprises: The product oil gas obtained by the reaction of the topmost reactor is input into a fractionating column. delivering the oil gas components stripped in the stripping unit to a fractionating column; separating the gaseous and liquid phase components in the product oil gas and the oil gas components using the fractionating column to obtain corresponding catalytic cracking / cleavage products.

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