A catalytic conversion method and system for reducing the aromatic content of gasoline

Abstract

This invention provides a catalytic conversion method for reducing the aromatic content of gasoline. The method includes the following steps: S1, contacting a hydrocarbon feedstock with a first catalyst in a riser reactor to perform a first catalytic conversion reaction, obtaining a first oil-catalyst mixture; S2, introducing the first oil-catalyst mixture into a fast bed reactor to contact with a second catalyst, performing a second catalytic conversion reaction, obtaining a second oil-catalyst mixture; S3, subjecting the second oil-catalyst mixture to gas-solid separation and stripping to obtain reacted oil gas and a mixed pre-regenerating agent; S4, introducing the mixed pre-regenerating agent into a regenerator for regeneration. This invention also provides a catalytic conversion system. Through the above technical solutions, this invention further reduces the aromatic content and benzene content of gasoline.

Description

Technical Field

[0001] This invention relates to the field of petrochemicals, and specifically to a catalytic conversion method and system for reducing the aromatic content of gasoline. Background Technology

[0002] In recent years, environmental regulations and gasoline quality standards have been continuously upgraded, with stricter requirements for the olefin, aromatic, and benzene content in automotive gasoline. The current standard requires that the aromatic content in gasoline not exceed 35% and the benzene content not exceed 0.8%. More than 70% of gasoline blending components come from catalytic cracking gasoline, with the remainder including reformed gasoline and alkylate oils. Therefore, reducing the aromatic and benzene content in catalytic cracking gasoline is of great significance for improving gasoline quality.

[0003] For example, CN101440302A discloses a method for reducing the benzene content in gasoline and improving the yield of liquid hydrocarbons in a catalytic cracking process, as well as a catalyst for this method. The method is characterized by setting up a catalytic reaction system in the catalytic cracking unit, introducing dry gas and gasoline fractions into the reaction system. Under the action of the catalyst, olefins in the dry gas react with benzene in the gasoline fractions to form macromolecules, and benzene is converted into alkylbenzenes. The catalyst consists of 15-95% active components and 5-85% binders and supports. The active components consist of modified ZSM-5 molecular sieves and modified Y molecular sieves.

[0004] For example, CN101362964A discloses a catalytic conversion method for reducing the benzene content of gasoline. This method involves contacting gasoline feedstock and gas containing small molecule olefins with a catalytic cracking catalyst at a temperature of 250-550℃ and a weight hourly space velocity of 2-100 h⁻¹. -1 The alkylation reaction is carried out under the following conditions: reaction pressure 0.1-1.0 MPa, catalyst to gasoline feedstock weight ratio 1-30, gasoline feedstock to small molecule olefin weight ratio 2-30, and steam to feedstock weight ratio 0.05-1.0. The reaction products are sent to the subsequent separation system, and the catalyst after the reaction is regenerated by stripping and coking and then recycled.

[0005] However, the aromatic content in the products obtained by existing catalytic cracking methods for reducing gasoline aromatic content still needs to be further reduced. Summary of the Invention

[0006] The purpose of this invention is to further reduce the aromatic content of gasoline.

[0007] To achieve the above objectives, the present invention provides a catalytic conversion method for reducing the aromatic content of gasoline. This catalytic conversion method includes the following steps: S1, contacting a hydrocarbon feedstock with a first catalyst in a riser reactor to perform a first catalytic conversion reaction, obtaining a first oil-catalyst mixture; S2, introducing the first oil-catalyst mixture into a fast bed reactor to contact with a second catalyst, performing a second catalytic conversion reaction, obtaining a second oil-catalyst mixture; S3, subjecting the second oil-catalyst mixture to gas-solid separation and stripping to obtain reaction oil gas and a mixed pre-regenerated agent; S4, introducing the mixed pre-regenerated agent into a regenerator for regeneration to obtain a mixed regenerated agent, then filtering the mixed regenerated agent using a catalyst filter installed in the regenerator to obtain a filtered second regenerated agent and the remaining first regenerated agent; and returning the first regenerated agent to step S1 as the first catalyst to participate in the first catalytic conversion reaction, and returning the second regenerated agent to step S2 as the second catalyst to participate in the second catalytic conversion reaction.

[0008] The present invention also provides a catalytic conversion system for reducing the aromatic content of gasoline. The catalytic conversion system includes a riser reactor, a fast bed reactor, a settling tank, and a regenerator. The upper end of the riser reactor is connected to the lower end of the fast bed reactor. The settling tank is equipped with a gas-solid separation device and a stripper. The oil-solid mixture inlet of the gas-solid separation device is connected to the upper end of the fast bed reactor, and the solid outlet of the gas-solid separation device is located in or above the stripper. The regenerator is connected to the stripper via a mixed regenerator transport connection. The upper middle part of the regenerator is provided with a regeneration zone, and the lower part is provided with a catalyst filtration zone. The catalyst filtration zone is equipped with a catalyst filter, which divides the catalyst filtration zone into an upper first filtration zone and a lower second filtration zone. The first filtration zone is connected to the riser reactor via a first regenerator transport connection, and the second filtration zone is connected to the fast bed reactor via a second regenerator transport connection.

[0009] Through the above technical solution, the present invention first reacts hydrocarbon feedstock with a first catalyst that can promote the conversion of hydrocarbon feedstock, and then reacts the resulting oil mixture with a second catalyst that can inhibit aromatization reaction, thereby reducing the aromatic content and benzene content in gasoline.

[0010] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0011] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0012] Figure 1 This is a schematic diagram of the structure of a catalytic conversion system according to one embodiment of the present invention.

[0013] Explanation of reference numerals in the attached figures

[0014] Figure 1 The reference numerals in the attached figures are explained as follows:

[0015] 1-Riser reactor; 2-Rapid bed reactor; 3-Settler

[0016] 4-Stripper 5-Second Filtration Zone 6-First Filtration Zone

[0017] 7-Catalyst filter 8-Regeneration zone

[0018] 11-Hydrocarbon feedstock; 12-Pre-lift gas; 13-Oil-agent mixture conveying pipe

[0019] 14-Stripping gas 15-Stripping baffle 16-Regenerating agent delivery pipe

[0020] 17-Cyclone separator; 18-Gas collection chamber; 19-Reaction oil and gas

[0021] 20 - Main airflow; 21 - First regenerant delivery pipe; 22 - Second regenerant delivery pipe

[0022] 23-Cyclone separator 24-Gas collection chamber 25-Regenerated flue gas

[0023] 26-Purge gas Detailed Implementation

[0024] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0025] refer to Figure 1This invention provides a catalytic conversion method for reducing the aromatic content of gasoline. The catalytic conversion method includes the following steps: S1, contacting a hydrocarbon feedstock with a first catalyst in a riser reactor to carry out a first catalytic conversion reaction, obtaining a first oil-catalyst mixture; S2, introducing the first oil-catalyst mixture into a fast bed reactor to contact with a second catalyst, carrying out a second catalytic conversion reaction, obtaining a second oil-catalyst mixture; S3, subjecting the second oil-catalyst mixture to gas-solid separation and stripping to obtain reaction oil gas and a mixed pre-regenerated agent; S4, introducing the mixed pre-regenerated agent into a regenerator for regeneration to obtain a mixed regenerated agent, and then using a catalyst filter provided in the regenerator to filter the mixed regenerated agent to obtain a filtered second regenerated agent and the remaining first regenerated agent; and returning the first regenerated agent to step S1 as the first catalyst to participate in the first catalytic conversion reaction, and returning the second regenerated agent to step S2 as the second catalyst to participate in the second catalytic conversion reaction.

[0026] In this invention, the materials that have undergone the first catalytic conversion in the riser reactor (including the first catalyst, reaction oil and gas, and fluidizing medium) are all introduced into the fast bed reactor without separation to contact the second catalyst and carry out the second catalytic conversion reaction, which means that the first catalytic conversion reaction and the second catalytic conversion reaction can be carried out in succession.

[0027] Optionally, to facilitate the separation of the first and second regenerators, the particle size of the first catalyst is larger than the pore size of the catalyst filter; the particle size of the second catalyst is smaller than the pore size of the catalyst filter. The pore size of the catalyst filter is 40–100 μm, preferably 60–80 μm.

[0028] The first catalyst contains 80-100% by mass of heavy oil catalyst and 0-20% by mass of light oil catalyst; the second catalyst contains 0-20% by mass of heavy oil catalyst and 80-100% by mass of light oil catalyst.

[0029] Preferably, the first catalyst contains 90-100% by mass of heavy oil catalyst and 0-10% by mass of light oil catalyst; the second catalyst contains 0-10% by mass of heavy oil catalyst and 90-100% by mass of light oil catalyst.

[0030] Optionally, the heavy oil catalyst comprises unmodified or modified Y-type molecular sieves, clay, and a binder. The clay can serve as an acidic matrix.

[0031] Optionally, based on the total weight of the heavy oil catalyst, the content of unmodified or modified Y-type molecular sieve is 10-80%, preferably 30-60%, the content of clay is 10-80%, preferably 15-60%, and the content of binder is 10-30%, preferably 10-20%.

[0032] Optionally, the particle size range of the heavy oil catalyst is 60–250 μm, preferably 80–200 μm.

[0033] In the heavy oil catalyst, the modified or unmodified Y-type molecular sieve may be selected from one or more of HY, USY, REUSY, REY, REHY, DASY, and REDASY, or Y-type molecular sieves obtained by treatment with various metal oxides. The clay is selected from various clays that can be used as catalyst components, such as kaolin, montmorillonite, and bentonite. The binder is selected from one or a mixture of two or three of silica sol, alumina sol, and boehmite, wherein the preferred binder is a double-alumina binder of alumina sol and boehmite.

[0034] Optionally, the light oil catalyst comprises unmodified or modified β-zeolite, a non-acidic matrix, and a binder.

[0035] Optionally, based on the total weight of the catalyst, the content of unmodified or modified β-zeolite is 10-60%, preferably 20-50%, the content of non-acidic matrix is ​​10-80%, preferably 20-70%, and the content of binder is 10-30%, preferably 10-20%.

[0036] Optionally, the particle size range of the light oil catalyst is 10–100 μm, preferably 30–80 μm.

[0037] In the light oil catalyst, the modified β-zeolite can be selected from β-type zeolites modified with phosphorus and transition metal M, wherein M is selected from one or more of Fe, Co, Ni, Cu, Mn, Zn, and Sn. The β-type zeolite modified with phosphorus and transition metal M can be prepared by various methods, such as introducing phosphorus and the transition metal M during the synthesis of the β-type zeolite, or introducing phosphorus and the transition metal M by ammonium exchange, phosphorus modification, modification with the transition metal M, and calcination after the synthesis of the β-type zeolite. The non-acidic matrix is ​​one or a mixture of silica, titanium dioxide, zirconium dioxide, and titanium-silicon zeolites. The binder is selected from one or a mixture of two or three of silica sol, alumina sol, and boehmite, wherein the preferred binder is a double-alumina binder of alumina sol and boehmite.

[0038] Optionally, the catalytic conversion method further includes purging the mixed regenerator on the catalyst filter to allow the second regenerator to pass through the catalyst filter. The gas used for purging can be an inert gas or purified regenerated flue gas.

[0039] The mixed regenerant is introduced into the regeneration zone of the regenerator for regeneration, and main air is introduced into the regeneration zone. The mixed regenerant enters the filtration zone of the regenerator and is filtered by the catalyst filter; what passes through the catalyst filter is the filtered second regenerant; what is retained by the catalyst filter is the remaining first regenerant.

[0040] Optionally, the regeneration conditions include: a regeneration temperature of 670–730°C, preferably 690–710°C, and a catalyst distribution density of 30–350 kg / m³. 3 Preferred weight is 80-250 kg / m³. 3 The dwell time of the main wind is 0.5 to 15 seconds, preferably 2 to 10 seconds.

[0041] Optionally, the reaction temperature of the riser reactor is 460–580°C, preferably 480–540°C, the agent-to-oil ratio is 1–15, preferably 2–8, and the reaction time is 1–10 seconds, preferably 2–8 seconds.

[0042] Optionally, the reaction temperature of the rapid bed reactor is 440–560°C, preferably 460–520°C, the agent-to-oil ratio is 2–20, preferably 4–15, and the reaction time is 1–15 seconds, preferably 2–10 seconds.

[0043] Optionally, the hydrocarbon feedstock is selected from one or more of the following: vacuum gas oil, atmospheric residue, vacuum residue, coking wax oil, deasphalted oil, furfural refined raffinate, coal liquefaction oil, oil sands oil, shale oil, Fischer-Tropsch synthetic distillate oil, or bio-oil.

[0044] Optionally, the method further includes introducing a pre-lifting gas into the bottom of the riser reactor. The pre-lifting gas may be selected from one or more of water vapor, nitrogen, and dry gas, with water vapor being preferred.

[0045] The present invention also provides a catalytic conversion system for reducing the aromatic content of gasoline. The catalytic conversion system includes a riser reactor, a fast bed reactor, a settling tank, and a regenerator. The upper end of the riser reactor is connected to the lower end of the fast bed reactor. The settling tank is equipped with a gas-solid separation device and a stripper. The oil-solid mixture inlet of the gas-solid separation device is connected to the upper end of the fast bed reactor, and the solid outlet of the gas-solid separation device is located in or above the stripper. The regenerator is connected to the stripper via a mixed regenerator transport connection. The upper middle part of the regenerator is provided with a regeneration zone, and the lower part is provided with a catalyst filtration zone. The catalyst filtration zone is equipped with a catalyst filter, which divides the catalyst filtration zone into an upper first filtration zone and a lower second filtration zone. The first filtration zone is connected to the riser reactor via a first regenerator transport connection, and the second filtration zone is connected to the fast bed reactor via a second regenerator transport connection.

[0046] The riser reactor is selected from one or a combination of two types: constant diameter riser reactor and variable diameter riser reactor. The riser reactor and the rapid bed reactor are arranged in series, with the riser reactor located below the rapid bed reactor. The height ratio of the riser reactor to the rapid bed reactor is 1:0.5 to 1.5, preferably 1:0.7 to 1.2.

[0047] The catalyst filter is preferably a plate filter, and the pore size of the catalyst filter is 40-100 μm, preferably 60-80 μm.

[0048] In a particularly preferred embodiment of the present invention, the catalytic conversion system includes a riser reactor 1, a fast bed reactor 2, a settling tank 3, and a regenerator. The riser reactor 1 and the fast bed reactor 2 are arranged in series, with the riser reactor 1 located below the fast bed reactor 2. The height ratio of the riser reactor 1 to the fast bed reactor 2 is 1:0.5 to 1.5, preferably 1:0.7 to 1.2. A cyclone separator (gas-solid separation device) 17 is installed in the upper part of the settling tank 3. The oil-solid mixture inlet of the cyclone separator 17 is connected to the top of the fast bed reactor 2 via an oil-solid mixture conveying pipe 13. The catalyst outlet of the cyclone separator 17 allows the catalyst to enter the stripper 4, and the oil-gas outlet of the cyclone separator 17 is connected to a gas collecting chamber 18. A mixed catalyst conveying connection 16 connects the regenerator and the stripper 4. A regeneration zone 8 is provided in the upper middle part of the regenerator, and a catalyst filtration zone is provided in the lower part. A catalyst filter 7 is provided in the catalyst filtration zone. The catalyst filter 7 divides the catalyst filtration zone into an upper first filtration zone 6 and a lower second filtration zone 5. The catalyst filter 7 is preferably a plate filter. The pore size of the catalyst filter 7 is 40–100 μm, preferably 60–80 μm. Main air 20 is introduced into the lower part of the regeneration zone to undergo a regeneration reaction with the mixed regenerator, and the resulting regenerated flue gas 25 is discharged from the device. The outlet of the stripper 4 is connected to the regeneration zone via a regenerator delivery pipe 16. The first filtration zone 6 is connected to the riser reactor 1 via a first regenerator delivery pipe 21, and the second filtration zone 5 is connected to the rapid bed reactor 2 via a second regenerator delivery pipe 22. The catalyst delivery speed can be adjusted by valves on the catalyst delivery pipes.

[0049] In a particularly preferred embodiment of the present invention, the hydrocarbon feedstock 11 is preheated to 180–340°C and then sprayed into the bottom of the riser reactor 1 through a nozzle. It contacts the first catalyst introduced into the bottom of the riser reactor 1 via the first regenerator line 21 and undergoes a first catalytic conversion reaction at a reaction temperature of 460–580°C, preferably 480–540°C, a catalyst-to-oil ratio of 1–15, preferably 2–8, and a reaction time of 1–10 seconds, preferably 2–8 seconds. The resulting first oil-catalyst mixture is then introduced into a fast bed reactor 2, where it contacts the second catalyst introduced into the bottom of the fast bed reactor 2 via the second regenerator line 22 and undergoes a second catalytic conversion reaction at a reaction temperature of 440–560°C, preferably 460–520°C, a catalyst-to-oil ratio of 2–20, preferably 4–15, and a reaction time of 1–15 seconds, preferably 2–10 seconds. The second oil-agent mixture obtained from the reaction is introduced into the cyclone separator 17 in the settling tank 3 for separation, and the resulting reaction oil gas 19 is led out through the gas collection chamber 18. The mixed reactant is introduced into the stripper 4, and the stripped mixed reactant is introduced into the regeneration zone 8 at the top of the regenerator through the reactant conveying pipe 16, with a regeneration temperature of 640-700℃, preferably 660-680℃, and a catalyst density of 50-400 kg / m³. 3 Preferred weight: 100–300 kg / m³ 3 The main air residence time is 0.5–20 s, preferably 2–10 s, to regenerate a mixed regenerant. The mixed regenerant enters the catalyst filtration zone at the bottom of the regenerator and is filtered by the catalyst filter 7 with the assistance of purge gas 26. The regenerant that passes through the catalyst filter 7 is the filtered second regenerant; the regenerant that is retained by the catalyst filter 7 is the remaining first regenerant. The second regenerant enters the second filtration zone 5 below the catalyst filter 7, while the first regenerant remains in the first filtration zone 6 above the catalyst filter 7. The first regenerant enters the riser reactor 1 from the first filtration zone 6 via the first regenerant transport connection 21 to participate in the first catalytic conversion; the second regenerant enters the fast bed reactor 2 from the second filtration zone 5 via the second regenerant transport connection 22 to participate in the second catalytic conversion. The regenerated flue gas 25 is separated by a cyclone separator 23 to remove a small amount of catalyst before being led out through the gas collection chamber 24. The reaction oil gas 19 enters the subsequent product separation system (not shown in the figure). In the product separation system, the catalytic cracking products are separated into dry gas, cracked gas, gasoline, diesel, and slurry oil.

[0050] The present invention will be further described in detail below through examples.

[0051] The catalysts used in the examples and comparative examples were self-made catalysts, designated CAT-1 and CAT-2, respectively. Their specific properties are shown in Table 1. The specific preparation process of the catalysts was as follows: molecular sieves were uniformly mixed, deionized water was added and stirred to obtain a molecular sieve slurry with a solid content of 20–40% by weight; clay (or non-acidic matrix), binder, and deionized water were mixed and stirred to obtain a support slurry with a solid content of 15–25% by weight; the homogenized molecular sieve slurry and the homogenized support slurry were mixed and stirred, and then spray-dried, washed, filtered, and dried sequentially to obtain the catalyst. Before the experiment, the catalyst was aged at 790°C and 100% steam for 12 hours.

[0052] The raw material oil used in the examples and comparative examples is wax oil, and its specific properties are shown in Table 2.

[0053] Table 1. Composition and properties of catalysts

[0054]

[0055]

[0056] Table 2 Composition and Properties of Wax Oils

[0057] project Wax oil <![CDATA[Density (20 °C) / (kg / m 3 )]]> 856.5 Residual carbon mass fraction / % 0.12 Elemental mass composition / % C 86.12 H 13.47 S 0.85 N 0.41 Mass family composition / % Saturated hydrocarbons 83.4 Aromatics 14.7 gelatinous 1.9 Asphalt <0.1 Metal mass composition (mg / kg) Fe 1.9 Ni 8.0 V 9.5 Na 3.1 Ca 1.8 Distillation range / ℃ Initial boiling point 284 10％ 342 30％ 390 50％ 420 70％ 449 90％ 497 Final boiling point 526

[0058] Examples 1-2

[0059] The experiment was conducted in Figure 1 The experiment was conducted on the apparatus shown. This apparatus includes a riser reactor and a rapid bed reactor. The riser reactor has an inner diameter of 16 mm and a length of 2000 mm, while the rapid bed reactor has an inner diameter of 35 mm and a length of 1800 mm. A catalyst filter with a pore size of 70 μm is installed in the lower part of the regenerator.

[0060] Wax oil and the first catalyst are introduced into a riser reactor for contact reaction. The resulting oil-catalyst mixture is then introduced into a fast bed reactor, where it contacts the second catalyst and continues to react. The resulting oil-catalyst mixture is separated by a cyclone separator. The mixed regenerated agent enters a stripper and then the regeneration zone in a regenerator for regeneration, yielding a mixed regenerated agent. This mixed regenerated agent enters the catalyst filtration zone at the bottom of the regenerator. After separation by the catalyst filter, it is divided into retained first regenerated agent and filtered second regenerated agent. The first regenerated agent is returned to the riser reactor for recycling, while the second regenerated agent is returned to the fast bed reactor for recycling. The oil and gas are then introduced into a fractionation system for separation. The reaction conditions and results are shown in Table 3.

[0061] Comparative Example 1

[0062] The method was the same as in Example 1, except that CAT-1 catalyst was used in both reaction zones. The reaction conditions and results are shown in Table 3.

[0063] Comparative Example 2

[0064] The experiment was conducted in Figure 1 The experiment was conducted on the apparatus shown. This apparatus includes a riser reactor and a rapid bed reactor. The riser reactor has an inner diameter of 16 mm and a length of 2000 mm, while the rapid bed reactor has an inner diameter of 35 mm and a length of 1800 mm. No catalyst filter is installed inside the regenerator.

[0065] A mixture of wax oil and CAT-1 and CAT-2 catalysts (in a 1:1 mass ratio) was introduced into the bottom of a riser reactor. The two catalysts reacted in contact within the riser reactor. The resulting oil-catalyst mixture was then introduced into a fast bed reactor for further reaction, with additional mixed catalyst added. The resulting oil-catalyst mixture was separated by a cyclone separator. The catalyst then entered a stripper and subsequently a regenerator for regeneration. The regenerated catalyst was returned to the riser reactor for recycling. The oil and gas mixture was introduced into a fractionation system for separation. The reaction conditions and results are shown in Table 3.

[0066] Table 3. Reaction conditions and results of Examples 1-2 and Comparative Examples 1-2

[0067]

[0068]

[0069] As shown in Table 3, the method and apparatus provided by this invention can reduce the content of aromatics and benzene in gasoline.

[0070] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0071] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0072] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A catalytic conversion method for reducing the aromatic content of gasoline, characterized in that, The catalytic conversion method includes the following steps: S1. The hydrocarbon feedstock is brought into contact with the first catalyst in a riser reactor to carry out the first catalytic conversion reaction, and the first oil-catalyst mixture is obtained. S2. The first oil-agent mixture is introduced into a fast bed reactor and contacted with the second catalyst to carry out the second catalytic conversion reaction, thereby obtaining the second oil-agent mixture. S3. The second oil mixture is subjected to gas-solid separation and stripping to obtain reactive oil gas and mixed pre-generated agent; S4. The mixed regenerator is introduced into the regenerator for regeneration to obtain a mixed regenerator. Then, the mixed regenerator is filtered using a catalyst filter provided in the regenerator to obtain a filtered second regenerator and the remaining first regenerator. The first regenerator is returned to step S1 as a first catalyst to participate in the first catalytic conversion reaction, and the second regenerator is returned to step S2 as a second catalyst to participate in the second catalytic conversion reaction. The particle size of the first catalyst is larger than the pore size of the catalyst filter; the particle size of the second catalyst is smaller than the pore size of the catalyst filter. The first catalyst contains 80-100% by mass of heavy oil catalyst and 0-20% by mass of light oil catalyst; the second catalyst contains 0-20% by mass of heavy oil catalyst and 80-100% by mass of light oil catalyst; the heavy oil catalyst comprises unmodified or modified Y-type molecular sieve, clay, and binder; based on the total weight of the heavy oil catalyst, the content of unmodified or modified Y-type molecular sieve is 10-80%, the content of clay is 10-80%, and the content of binder is 10-30%; The light oil catalyst comprises unmodified or modified β-zeolite, a non-acidic matrix, and a binder. By total weight of the light oil catalyst, the content of unmodified or modified β-zeolite is 10-60%, the content of non-acidic matrix is ​​10-80%, and the content of binder is 10-30%.

2. The catalytic conversion method according to claim 1, wherein, The first catalyst contains 90-100% by mass of heavy oil catalyst and 0-10% by mass of light oil catalyst; the second catalyst contains 0-10% by mass of heavy oil catalyst and 90-100% by mass of light oil catalyst.

3. The catalytic conversion method according to claim 2, wherein, Based on the total weight of the heavy oil catalyst, the content of unmodified or modified Y-type molecular sieve is 30-60%, the content of clay is 15-60%, and the content of binder is 10-20%. The particle size range of the heavy oil catalyst is 60–250 μm.

4. The catalytic conversion method according to claim 3, wherein, The particle size range of the heavy oil catalyst is 80–200 μm.

5. The catalytic conversion method according to claim 1 or 4, wherein, Based on the total weight of the light oil catalyst, the content of unmodified or modified β-zeolite is 20-50%, the content of non-acidic matrix is ​​20-70%, and the content of binder is 10-20%. The particle size range of the light oil catalyst is 10–100 μm; The non-acidic matrix is ​​one or more of silicon dioxide, titanium dioxide, zirconium dioxide, and titanium-silicon molecular sieves.

6. The catalytic conversion method according to claim 5, wherein the particle size range of the light oil catalyst is 30-80 μm.

7. The catalytic conversion method according to claim 1, wherein, The catalytic conversion method further includes purging the mixed regenerator on the catalyst filter so that the second regenerator passes through the catalyst filter.

8. The catalytic conversion method according to claim 1, wherein, The regeneration conditions include: a regeneration temperature of 670–730℃ and a catalyst distribution density of 30–350 kg / m³. 3 The duration of the prevailing wind is 0.5 to 15 seconds.

9. The catalytic conversion method according to claim 8, wherein, The regeneration conditions include: a regeneration temperature of 690–710℃ and a catalyst distribution density of 80–250 kg / m³. 3 The duration of the prevailing wind is 2 to 10 seconds.

10. The catalytic conversion method according to claim 1, wherein, The reaction temperature of the riser reactor is 460–580°C, the agent-to-oil ratio is 1–15, and the reaction time is 1–10 seconds. The rapid bed reactor has a reaction temperature of 440–560°C, a catalyst-to-oil ratio of 2–20, and a reaction time of 1–15 seconds.

11. The catalytic conversion method according to claim 10, wherein, The reaction temperature of the riser reactor is 480–540°C, the agent-to-oil ratio is 2–8, and the reaction time is 2–8 seconds. The rapid bed reactor has a reaction temperature of 460–520°C, a catalyst-to-oil ratio of 4–15, and a reaction time of 2–10 seconds.

12. The catalytic conversion method according to claim 1, wherein, The hydrocarbon feedstock is selected from one or a mixture of two or more of the following: vacuum wax oil, atmospheric residue oil, vacuum residue oil, coking wax oil, deasphalted oil, furfural refined raffinate oil, coal liquefaction oil, oil sands oil, shale oil, and Fischer-Tropsch synthetic distillate oil.

13. A catalytic conversion system for use in the catalytic conversion method according to any one of claims 1-12, characterized in that, The catalytic conversion system includes a riser reactor, a fast bed reactor, a settler, and a regenerator; the upper end of the riser reactor is connected to the lower end of the fast bed reactor. The settler is equipped with a gas-solid separation device and a stripper. The oil-solid mixture inlet of the gas-solid separation device is connected to the upper end of the rapid bed reactor, and the solid outlet of the gas-solid separation device is located in or above the stripper. The regenerator and the stripper are connected by a mixed feed agent conveying connection; the lower part of the regenerator is provided with a catalyst filtration zone, and a catalyst filter is provided in the catalyst filtration zone, which divides the catalyst filtration zone into an upper first filtration zone and a lower second filtration zone. The first filtration zone is connected to the riser reactor via a first regenerant delivery connection; the second filtration zone is connected to the rapid bed reactor via a second regenerant delivery connection.

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