CN112708452B

CN112708452B - Method for producing gasoline with low olefin content

Info

Publication number: CN112708452B
Application number: CN201911025818.8A
Authority: CN
Inventors: 杨超; 朱根权; 李红波; 沙有鑫; 马文明; 成晓洁
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2019-10-25
Filing date: 2019-10-25
Publication date: 2023-04-07
Anticipated expiration: 2039-10-25
Also published as: CN112708452A

Abstract

The invention relates to the field of petroleum processing, and discloses a method for producing gasoline with low olefin content, which comprises the following steps: (1) Introducing a catalyst from the upper part of the first reactor, introducing recycle oil from the bottom of the first reactor, and carrying out a cracking reaction by countercurrent contact between the catalyst and the recycle oil in the first reactor to obtain a first reaction oil gas and a first post-reaction catalyst; (2) Introducing the catalyst after the first reaction from the upper part of the second reactor, introducing fresh raw oil from the bottom of the second reactor, and carrying out a cracking reaction by countercurrent contact between the catalyst after the first reaction and the fresh raw oil in the second reactor to obtain a second reaction oil gas and a second catalyst after the second reaction; (3) And (3) stripping and regenerating the catalyst after the second reaction, and introducing the obtained regenerated catalyst into the first reactor for recycling. Compared with the prior art, the method provided by the invention not only can obviously reduce the olefin content of the gasoline, but also can obtain higher gasoline yield, and simultaneously obviously reduces the coke yield.

Description

Method for producing gasoline with low olefin content

Technical Field

The invention relates to the field of petroleum processing, in particular to a method for producing gasoline with low olefin content.

Background

With the increasing attention of people on environmental protection, countries in the world have set strict new standards for clean gasoline. The European V automotive gasoline standard promulgated in 2011 in the European Union stipulates that the olefin content be below 18V%. The national VI automotive gasoline standard promulgated in 2016, 12, 23 days in China requires that the olefin content is below 18v percent. At present, automobile gasoline blending pools in developed countries are widely distributed, wherein about 1/3 of the blending pools are catalytic cracking gasoline, about 1/3 of the blending pools are reformed gasoline without olefin content, and the gasoline which does not contain aromatic hydrocarbon or olefin, such as isomerization and alkylation accounts for about 1/3 of the blending pools, and a commercial gasoline can reach the standard by adopting a gasoline blending method. The main component of the motor gasoline in China is catalytic cracking gasoline (namely FCC gasoline) which accounts for more than 70 percent in a gasoline blending pool, and the catalytic cracking gasoline has the characteristic of high olefin (30-45 v percent) content. Under the premise of no change of the gasoline pool structure in China, the catalytic cracking gasoline olefin meeting the national VI automotive gasoline standard needs to be reduced to below 25 v%. The current technologies for reducing the olefin content in gasoline are mainly focused on developing novel catalysts, auxiliaries or developing new process technologies.

The riser reactor is a gas-solid parallel-flow upward riser reactor, and has the advantages of high gas-solid contact efficiency and high gas-solid flux, but the radial flow structure of the riser reactor has serious non-uniformity and large axial back mixing. The descending bed reactor is a gas-solid parallel flow descending reactor, the gas-solid back mixing is small, the gas-solid contact time is short, the uniformity of a radial flow structure is high, and the defect of low particle concentration exists. The gas-solid reverse contact can strengthen the mass transfer and heat transfer between the two phases, and the gas-solid reverse contact can improve the particle concentration of the bed layer.

CN109554192A discloses a method for catalytic conversion of kerogen shale oil, which adopts a fluidized bed reactor with relatively uniform axial temperature, and the kerogen shale oil gas and a catalyst are in dense-phase countercurrent contact, and the method can ensure that the flowing state of the catalyst and the oil gas is relatively stable, is beneficial to reducing side reactions such as thermal cracking and the like, and improves the gasoline selectivity. However, the method needs to arrange a catalyst cooler to cool the catalyst to be not higher than 620 ℃ and then return the catalyst to the fluidized bed reactor, the high temperature of the regenerated catalyst cannot be efficiently utilized in the cracking reaction, and the method does not relate to the purpose of reducing the olefin content of gasoline.

CN105586080A discloses a shale oil catalytic cracking processing method, which adopts a moving bed reactor, the particle size of a catalyst is 1-6mm, shale oil is in reverse contact with the catalyst, two functions of shale oil adsorption denitrification and shale oil hydrocarbon catalytic cracking are realized, the method can reduce the yield of dry gas and coke, and the yield of liquid products is improved. However, the main reason for realizing the reverse contact of the oil agent by the method is that the catalyst particles are large, and the large-particle catalyst has low activity and effective utilization rate and poor stripping performance and regeneration effect.

In conclusion, in order to upgrade the gasoline quality in China, a novel catalytic conversion process which is simple and feasible and can produce gasoline with low olefin content is urgently needed to be developed.

Disclosure of Invention

The invention aims to overcome the problems in the prior art and provide a method for producing gasoline with low olefin content.

In order to achieve the above object, the present invention provides a method for producing a low olefin content gasoline, comprising:

(1) Introducing a catalyst from the upper part of the first reactor, introducing recycle oil from the bottom of the first reactor, and carrying out a cracking reaction by countercurrent contact between the catalyst and the recycle oil in the first reactor to obtain a first reaction oil gas and a first post-reaction catalyst;

(2) Introducing the catalyst after the first reaction from the upper part of the second reactor, introducing fresh raw oil from the bottom of the second reactor, and carrying out cracking reaction on the catalyst after the first reaction and the fresh raw oil in the second reactor by countercurrent contact to obtain second reaction oil gas and a catalyst after the second reaction;

(3) And (3) stripping and regenerating the catalyst after the second reaction, and introducing the obtained regenerated catalyst into the first reactor for recycling.

Preferably, the first reactor and the second reactor are dilute phase transport bed reactors.

Preferably, the catalyst contains an active component and an inert component; further preferably, the catalyst is spherical and the active component is wrapped outside the inert component.

Preferably, the catalyst has an average particle size of from 70 μm to 2mm, more preferably from 150 μm to 1mm.

Compared with the prior art, the method provided by the invention can obviously reduce the olefin content of the gasoline, can obtain higher gasoline yield and obviously reduce the coke yield at the same time.

Drawings

FIG. 1 is a schematic flow diagram of one embodiment of the method of the present invention.

Description of the reference numerals

1: first reactor 2: second reactor

3: the regenerator 4: regenerated catalyst distributor

5: catalyst distributor 6: steam stripping device

11: the recycle oil inlet 12: first reaction oil gas outlet

13: catalyst conveying pipe

21: fresh feed oil inlet 22: second reaction oil gas outlet

31: regeneration air inlet 32: regenerated flue gas outlet

33: first regenerated catalyst inclined tube 34: second regenerated catalyst inclined tube

61: stripping steam inlet 62: spent catalyst inclined tube

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

In the present invention, the use of directional terms such as "upper, lower, top, bottom" without a contrary intention, generally refers to upper, lower, top, bottom as illustrated in the accompanying drawings.

The invention provides a method for producing gasoline with low olefin content, which comprises the following steps:

According to the present invention, preferably, the first reactor and the second reactor are dilute phase transport bed reactors; further preferably, the average void fraction of solids during dilute phase transport in the first reactor and the second reactor is greater than 0.8, more preferably between 0.8 and 0.9.

According to the method provided by the present invention, the first reactor and the second reactor are not particularly limited in structure, and the first reactor and the second reactor may be each independently of the other, of equal diameter, variable diameter, straight tube, or curved tube. Preferably, the first reactor and the second reactor are each independently straight tubes of equal or varying diameter, or curved tubes of equal or varying diameter. Further preferably, the first reactor and the second reactor are each independently straight tubes of equal diameter.

According to a preferred embodiment of the present invention, the first reactor and the second reactor are each independently a riser reactor.

The present invention has no particular limitation in inner diameter and height of the first and second reactors, and those skilled in the art can appropriately select them according to the material throughput and material residence time, and preferably, the ratio of height to diameter of the first and second reactors is 20 to 100:1.

according to a preferred embodiment of the invention, the catalyst contains an active component and an inert component. The adoption of the preferred embodiment is more beneficial to the counter-current contact reaction and can ensure the exertion of the catalyst activity.

Preferably, the catalyst is spherical and the active component is wrapped outside the inert component. The spherical shape of the present invention also includes a spheroidal shape without specific reference.

Further preferably, the catalyst has an average particle size of 70 μm to 2mm, more preferably 150 μm to 1mm. The average particle diameter referred to herein refers to the linear average diameter of the catalyst.

According to a preferred embodiment of the invention, the mass ratio of the inert component to the active component is between 1 and 10:1, preferably 3 to 7:1.

the active ingredients are selected from a wide range of materials, preferably comprising zeolites, inorganic oxides and optionally clays. By "optional" is meant that the active ingredient may or may not contain clay.

Preferably, the content of the zeolite is 1-60 wt%, the content of the inorganic oxide is 5-99 wt%, and the content of the clay is 0-70 wt% based on the total amount of the active components; further preferably, the content of the zeolite is 30 to 60 wt%, the content of the inorganic oxide is 10 to 50 wt%, and the content of the clay is 10 to 40 wt%. The zeolite may be at least one selected from the group consisting of rare earth-containing or non-rare earth-containing Y or HY type zeolite, rare earth-containing or non-rare earth-containing ultrastable Y type zeolite, ZSM-5 series zeolite, high-silica zeolite having a pentasil structure, and beta zeolite. The inorganic oxide is preferably selected from silicon dioxide (SiO) as a binder ₂ ) And/or aluminum oxide (Al) ₂ O ₃ ). The clay may be various clays conventionally used in the art, such as kaolin and/or halloysite.

According to a preferred embodiment of the invention, the inert component is selected from the group consisting of iron, copper, cobalt, nickel and SiO ₂ At least one of (a).

The catalyst with the structure and the composition can further improve the yield of the gasoline and further reduce the content of olefin in the gasoline. The method for preparing the catalyst is not particularly limited, and the present invention provides an exemplary illustration of a specific method of the above catalyst, and is not intended to limit the present invention.

The catalyst can be prepared by the following method, the preparation method of the micron-sized inert component belongs to the technical field of powder metallurgy, and preferably, the method comprises the following steps: the micron-sized inert component (for example, 70-2 mm) is placed in a rotating disc inclined at 30-60 degrees, active component powder and a mist-shaped binder (preferably water) are sprayed, the inert component gradually grows into larger round balls along with the continuous rotation of the rotating disc, the friction coefficient of the larger round balls is small, the inert component floats on the surface and rolls out from the lower edge of the rotating disc when the particle size requirement is met, and therefore the required catalyst is prepared.

The method for obtaining the micron-sized inert component is not particularly limited, and may be any suitable conventional technique, for example, by heating inert component powder to form molten droplets, rapidly cooling, solidifying to form spherical inert powder (which may be carried out in a conveying reactor), and sieving to obtain the micron-sized inert component (which may be carried out in a fluidized bed) as described above.

According to the invention, the average particle size and the active component content of the prepared catalyst can be controlled by adjusting the inclination angle and the rotation speed of the rotating disc. On the basis of the above disclosure, the person skilled in the art knows how to prepare catalysts of fixed size and specific active component content.

According to the present invention, preferably, the mass ratio of the recycle oil to the fresh raw oil is 0.1 to 0.6:1, preferably 0.15 to 0.35:1.

according to a preferred embodiment of the present invention, the reaction conditions of the first reactor comprise: the inlet temperature of the recycle oil is 600-670 ℃, more preferably 620-650 ℃, the oil gas retention time is 0.1-5 seconds, more preferably 0.5-2 seconds, and the weight ratio of the oil to the solvent is 1-50, more preferably 10-30.

According to a preferred embodiment of the present invention, the reaction conditions of the second reactor comprise: the fresh raw oil inlet temperature is 480-530 ℃, the further optimization is 490-520 ℃, the oil gas residence time is 0.5-5 seconds, the further optimization is 1-3 seconds, and the weight ratio of the agent to the oil is 1-50, the further optimization is 8-20.

According to a most preferred embodiment of the present invention, a process for producing a low olefin content gasoline comprises:

(1) Introducing a catalyst from the upper part of a first reactor, introducing recycle oil from the bottom of the first reactor, and carrying out a cracking reaction by countercurrent contact between the catalyst and the recycle oil in the first reactor to obtain a first reaction oil gas and a first post-reaction catalyst, wherein the reaction conditions of the first reactor comprise: the inlet temperature of the recycle oil is 600-670 ℃, preferably 620-650 ℃, the oil gas residence time is 0.1-5 seconds, preferably 0.5-2 seconds, the weight ratio of the oil to the solvent is 1-50, preferably 10-30;

(2) Introducing a catalyst after the first reaction from the upper part of a second reactor, introducing fresh raw oil from the bottom of the second reactor, and carrying out a cracking reaction by countercurrent contact between the catalyst after the first reaction and the fresh raw oil in the second reactor to obtain a second reaction oil gas and a catalyst after the second reaction, wherein the reaction conditions of the second reactor comprise: the inlet temperature of fresh raw oil is 480-530 ℃, preferably 490-520 ℃, the oil gas retention time is 0.5-5 seconds, preferably 1-3 seconds, the weight ratio of the agent to the oil is 1-50, preferably 8-20;

(3) Stripping and regenerating the catalyst after the second reaction, and introducing the obtained regenerated catalyst into the first reactor for recycling;

wherein the catalyst contains an active component and an inert component; the catalyst is spherical, and the active component is wrapped outside the inert component.

The inventor of the invention discovers in the research process that the catalyst is uniquely designed, and the catalyst is used for producing the gasoline with low olefin content in a reactor mode that the catalyst is in countercurrent contact with the gasoline from top to bottom along with the gravity, wherein the first reactor is used for processing the olefin and the diesel oil light fraction in the gasoline at high temperature, short retention time and high activity, so that the diesel oil light fraction is converted into the gasoline fraction to ensure the maximum gasoline yield, and the olefin in the gasoline fraction is converted into the micromolecule low-carbon olefin to reduce the olefin content in the gasoline; the second reactor adopts low-temperature and low-activity catalyst to process fresh raw oil which is easy to crack, and can improve the selectivity of gasoline. By adopting the preferred embodiment, the olefin content of the gasoline can be further reduced, higher gasoline yield can be obtained, and the coke yield is obviously reduced.

According to the invention, the fresh raw oil is preferably petroleum hydrocarbon and/or mineral oil; wherein the petroleum hydrocarbon is selected from at least one of vacuum gas oil, atmospheric gas oil, coker gas oil, deasphalted oil, vacuum residue, atmospheric residue, and hydrogenated heavy oil; wherein the mineral oil is selected from at least one of coal liquefaction oil, oil sand oil, shale oil, synthetic oil, and partial fraction or whole fraction of animal and vegetable oil and fat. In the present invention, the fresh feedstock refers to the feedstock which is reacted for the first time in the process of the present invention.

According to the invention, in particular, the method further comprises: and sending the first reaction oil gas and/or the second reaction oil gas into a subsequent separation system. Preferably, the first reaction oil gas and the second reaction oil gas are mixed and jointly sent to a subsequent separation system.

According to the invention, preferably, the recycle oil is a fraction with a distillation range of 40-300 ℃ in a cracked product, more preferably a fraction with a distillation range of 40-140 ℃ in a cracked product and/or a fraction with a distillation range of 200-260 ℃ in a cracked product, wherein the cracked product is a product obtained by mixing a first reaction oil gas and a second reaction oil gas.

The stripping and regeneration method in step (3) is not particularly limited, and the stripping and regeneration method is well known to those skilled in the art and will not be described herein.

According to the method provided by the invention, preferably, the method further comprises introducing the regenerated catalyst obtained in the step (3) into the second reactor for recycling. In this preferred embodiment, the regenerated catalyst obtained in step (3) and the catalyst after the first reaction are introduced together into the second reactor and used as a catalyst.

Further preferably, in the second reactor, the mass ratio of the introduced amount of the regenerated catalyst to the introduced amount of the catalyst after the first reaction is from 0.1 to 1:1, more preferably 0.1 to 0.5:1.

the method provided by the present invention is described in detail below with reference to the accompanying drawings, but the present invention is not limited thereto.

As shown in fig. 1, the regenerated catalyst enters the regenerated catalyst distributor 4 of the first reactor 1 through the first regenerated catalyst inclined tube 33, the catalyst flows from top to bottom under the action of gravity, the recycle oil fraction is injected from the bottom of the first reactor 1 through the recycle oil inlet 11, and contacts and cracks with the catalyst along the first reactor 1 in a counter-current and upward manner, and the cracked product flows out from the first reaction oil gas outlet 12. The catalyst after the reaction in the first reactor 1 enters the catalyst distributor 5 through the catalyst conveying pipe 13, the catalyst after the first reaction flows downwards from the upper part of the second reactor 2 along the gravity direction, fresh raw oil is injected from a fresh raw oil inlet 21 at the bottom of the second reactor, and is subjected to countercurrent upward contact cracking with the catalyst after the first reaction along the second reactor 2, the regenerated catalyst can also directly enter the catalyst distributor 5 through a second regenerated catalyst inclined pipe 34, the cracked product of the second reactor 2 flows out from a second reaction oil gas outlet 22, and the second reaction oil gas and the first reaction oil gas jointly enter a subsequent separation system. The catalyst reacted in the second reactor 2 is stripped in the stripper 6 and then enters the regenerator 3 through the spent catalyst inclined tube 62 for coke burning regeneration, and the regenerated catalyst returns to the first reactor 1 and the optional second reactor 2 for recycling.

The process according to the invention is further illustrated by the following examples, without the invention being restricted thereby.

The basic properties of the fresh hydrocarbon feedstock used in the examples and comparative examples are shown in table 1. The essential properties of the recycle oil fraction used are shown in Table 2.

TABLE 1

TABLE 2 recycle oil

Example 1

The catalyst used in this example had an average particle diameter of 158 μm and a mass ratio of the inert component to the active component of the catalyst was 3.

The process was carried out in a medium-sized apparatus for continuous reaction-regeneration operation, as shown in FIG. 1, wherein the inner diameter (diameter) of the riser reactor of the first reactor 1 was 28 mm and the height was 2 m. The second reactor 2 had a riser reactor internal diameter (diameter) of 38 mm and a height of 6 m. The medium-sized devices use electrical heating to maintain the temperature of the reaction-regeneration system.

The catalyst used in this example consisted of an active component and an inert component, wherein the inert component was spherical iron having an average particle size of 110 μm, and the active component was a powder consisting of 55 wt% of ZSM-5 zeolite, 20 wt% of kaolin and 25 wt% of alumina. The spherical iron was placed in a 50 ° inclined turntable, and active ingredient powder and atomized water were sprayed in at a turntable speed of 100rpm. With the continuous rotation of the rotating disc, the active component is wrapped outside the spherical iron, the spherical iron gradually grows into larger spheres, the spheres float on the surface of the rotating disc and roll, and the spheres with the diameter of 140-170 μm roll out from the lower edge of the rotating disc to form the catalyst. The average particle size of the catalyst is 158 μm, and the mass ratio of the inert component to the active component of the catalyst is 3. The catalyst is treated by saturated steam hydrothermal aging at 800 ℃ for 14 hours before use.

The regenerated catalyst with the temperature of about 690 ℃ enters the regenerated catalyst distributor 4 of the first reactor 1 through the first regenerated catalyst inclined tube 33, the catalyst flows from top to bottom under the action of gravity, the first recycled oil fraction is injected from the bottom of the first reactor through the recycled oil inlet 11 under the action of atomized steam, and is in contact cracking with the catalyst along the first reactor 1 in a countercurrent and upward manner, and the reaction conditions in the first reactor are listed in table 3. Cracked products flow out of the first reaction oil gas outlet 12. The average void fraction of solids during dilute phase transport in the first reactor was 0.84.

The catalyst reacted in the first reactor 1 directly enters the catalyst distributor 5 through the catalyst conveying pipe 13 and the regenerated catalyst through the second regenerated catalyst inclined pipe 34, the catalyst and the regenerated catalyst after the first reaction flow downwards from the upper part of the second reactor 2 along the gravity direction, fresh raw oil is injected from the fresh raw oil inlet 21 at the bottom of the second reactor under the action of atomized steam, and is subjected to contact cracking along the second reactor 2 and the catalyst after the first reaction in a countercurrent upward manner, and the reaction conditions in the second reactor are listed in table 3. Cracked products of the second reactor 2 flow out of the second reaction oil gas outlet 22. The average void fraction of solids during dilute phase transport in the second reactor was 0.82.

The catalyst reacted in the second reactor 2 is stripped by steam injected from a stripping steam inlet 61 in a stripper 6, enters the regenerator 3 through a spent catalyst inclined pipe 62 and is in contact with heated air injected from a regeneration air inlet 31 for regeneration at 700 ℃, regenerated flue gas is discharged from a regenerated flue gas outlet 32, and the regenerated catalyst which is burnt, regenerated and has activity recovered is returned to the first reactor 1 and the second reactor 2 for recycling. The reaction oil gas of the first reactor and the reaction oil gas of the second reactor enter a subsequent separation system and are separated into dry gas, liquefied gas, recycle oil, gasoline fraction, diesel oil fraction and heavy oil fraction. Returning the recycle oil to the first reactor for reaction. The results are shown in Table 3.

Example 2

According to the method of example 1, except that the inert component of the catalyst was spherical iron having an average particle size of 440 μm, the spherical iron was placed in a rotating disk inclined at 50 °, active component powder and atomized water were sprayed in, the rotating disk rotating speed was 105rpm, and a catalyst having an average particle size of 600 μm was obtained, the mass ratio of the inert component to the active component of the catalyst was 3. Wherein the active component is powder consisting of 55 wt% of ZSM-5 zeolite, 20 wt% of kaolin and 25 wt% of alumina. The results are shown in Table 3.

Example 3

According to the method of example 1, except that the inert component of the catalyst was spherical copper having an average particle size of 250 μm, the spherical copper was placed in a rotating disk inclined at 48 °, active component powder and atomized water were sprayed in, the rotating disk rotating speed was 92rpm, and a catalyst having an average particle size of 300 μm was obtained, the mass ratio of the inert component to the active component of the catalyst was 7. Wherein the active component is powder consisting of 60 wt% of ZSM-5 zeolite, 25 wt% of kaolin and 15 wt% of alumina. The results are shown in Table 3.

Example 4

The process of example 1 was followed except that a second recycle oil recycle was added. The results are shown in Table 3.

Comparative example 1

The process of example 1 was followed except that the first reactor 1 was not subjected to the treatment of the first recycle oil, and specifically, acidic water was injected from the recycle oil inlet 11 to maintain the outlet temperature of the first reactor 1. The results are shown in Table 3.

Comparative example 2

The process of example 1 is followed except that the first reactor 1 and the second reactor 2 both use regenerated catalyst, i.e. the catalyst reacted in the first reactor 1 is directly fed to the regenerator for regeneration. The results are shown in Table 3.

Comparative example 3

The process of example 1 was followed except that the first reactor 1 and the second reactor 2 both flowed from bottom to top with the regenerated catalyst and the hydrocarbon feedstock, and the catalyst used did not contain inert components and had an average particle size of 78 μm. The results are shown in Table 3.

TABLE 3

As can be seen from the data in Table 3, the method provided by the invention can obviously reduce the olefin content of the gasoline, can obtain higher gasoline yield, and can obviously reduce the coke yield.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. A process for producing a low olefin content gasoline, the process comprising:

(2) Introducing the catalyst after the first reaction from the upper part of the second reactor, introducing fresh raw oil from the bottom of the second reactor, and carrying out a cracking reaction by countercurrent contact between the catalyst after the first reaction and the fresh raw oil in the second reactor to obtain a second reaction oil gas and a second catalyst after the second reaction;

wherein the average particle size of the catalyst is 150 mu m-2mm;

the first reactor and the second reactor are dilute phase conveying bed reactors, and the average solid porosity is respectively and independently more than 0.8 in the dilute phase conveying process in the first reactor and the second reactor;

the catalyst contains an active component and an inert component, the catalyst is spherical, and the active component is wrapped outside the inert component;

the mass ratio of the inert component to the active component is 1-10:1;

the active component comprises a zeolite, an inorganic oxide, and optionally a clay;

the reaction conditions of the first reactor include: the inlet temperature of the recycle oil is 600-670 ℃, the oil gas retention time is 0.1-5 seconds, and the weight ratio of the oil to the solvent is 1-50;

the reaction conditions of the second reactor include: the inlet temperature of fresh raw oil is 480-530 ℃, the oil gas retention time is 0.5-5 seconds, and the weight ratio of the agent to the oil is 1-50;

the fresh raw oil is at least one selected from coal liquefied oil, oil sand oil, shale oil, vacuum gas oil, atmospheric gas oil, coking gas oil, deasphalted oil, vacuum residual oil, atmospheric residual oil, hydrogenated heavy oil, synthetic oil and animal and vegetable oil;

the recycle oil is a fraction with the distillation range of 40-300 ℃ in the cracked product.

2. The process of claim 1, wherein the average void fraction of solids during dilute phase transport in the first and second reactors is from 0.8 to 0.9.

3. A process according to claim 1 or 2, wherein the first and second reactors are each independently straight or curved of equal or varying diameter.

4. A process according to claim 1 or 2, wherein the catalyst has an average particle size of from 150 μm to 1mm.

5. The method according to claim 1 or 2, wherein the mass ratio of the inert component to the active component is 3-7:1.

6. the process according to claim 1 or 2, wherein the zeolite is present in an amount of 1 to 60 wt%, the inorganic oxide is present in an amount of 5 to 99 wt% and the clay is present in an amount of 0 to 70 wt%, based on the total amount of the active components.

7. The method according to claim 1 or 2, wherein the zeolite is selected from at least one of Y or HY type zeolite with or without rare earth, ultrastable Y type zeolite with or without rare earth, ZSM-5 series zeolite, high silica zeolite having pentasil structure, and beta zeolite.

8. The process according to claim 1 or 2, wherein the inert component is selected from iron, copper, cobalt, nickel and SiO ₂ At least one of (a).

9. The process according to claim 1 or 2, wherein the mass ratio of the recycle oil to the fresh raw oil is 0.1-0.6:1.

10. the method according to claim 8, wherein the mass ratio of the recycle oil to the fresh raw oil is 0.15-0.35:1.

11. the method of claim 1 or 2, wherein the reaction conditions of the first reactor comprise: the inlet temperature of the recycle oil is 620-650 ℃, the oil gas retention time is 0.5-2 seconds, and the weight ratio of the oil to the solvent is 10-30;

the reaction conditions of the second reactor include: the fresh raw oil inlet temperature is 490-520 ℃, the oil gas retention time is 1-3 seconds, and the weight ratio of the agent to the oil is 8-20.

12. The method of claim 1 or 2, wherein the cracked product is a mixture of a first reacted hydrocarbon and a second reacted hydrocarbon.

13. The process according to claim 1 or 2, wherein the recycle oil is a fraction having a distillation range of 40 to 140 ℃ in the cracked product and/or a fraction having a distillation range of 200 to 260 ℃ in the cracked product.

14. The method according to claim 1 or 2, wherein the method further comprises introducing the regenerated catalyst obtained in the step (3) into the second reactor for recycling.

15. The process according to claim 1 or 2, wherein in the second reactor, the mass ratio of the introduced amount of the regenerated catalyst to the introduced amount of the catalyst after the first reaction is from 0.1 to 1:1.