CN113736511A

CN113736511A - Method for converting hydrocarbon oil

Info

Publication number: CN113736511A
Application number: CN202010476022.0A
Authority: CN
Inventors: 白风宇; 唐津莲; 陈骞; 毛安国
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: 2020-05-29
Filing date: 2020-05-29
Publication date: 2021-12-03

Abstract

The invention relates to the technical field of catalytic conversion of hydrocarbon oil in the absence of hydrogen, and discloses a hydrocarbon oil conversion method, which comprises the following steps: (1) carrying out catalytic cracking reaction on a hydrogenated catalytic diesel raw material and a catalyst in a first reaction zone to obtain a material flow I, wherein the first reaction zone contains a riser reactor; (2) introducing a transalkylation agent and the material flow I into a second reaction zone for transalkylation reaction to obtain a material flow II; (3) and separating the material flow II to obtain reaction oil gas and a spent catalyst. The method provided by the invention has the advantages that firstly, the reduction effect of the hydrogenated catalytic diesel oil is obvious, and the treatment capacity of the hydrogenated diesel oil raw material can reach more than 70 percent, namely, the conversion rate of the hydrogenated catalytic diesel oil is high; secondly, the content of aromatic hydrocarbon in the gasoline in the obtained reaction oil gas is increased; thirdly, the diesel oil load can be reduced, and simultaneously the yield of high-quality aromatic hydrocarbon products, especially the yield of Paraxylene (PX), can be increased remarkably.

Description

Method for converting hydrocarbon oil

Technical Field

The invention relates to the technical field of catalytic conversion of hydrocarbon oil under the condition of no hydrogen, in particular to a hydrocarbon oil conversion method.

Background

With the growth of national economy and the influence of factors such as road traffic electrification process, in recent years, the demand of diesel oil in the domestic product oil market is reduced to some extent, so that the diesel oil is taken out for low-quality diesel oil and increasingly becomes one of the primary problems to be considered by oil refining enterprises. Meanwhile, the demand of the domestic market for aromatic hydrocarbon products is rapidly increased, the conversion is carried out in the chemical industry direction, and the yield increase of high-value aromatic hydrocarbon products represented by Paraxylene (PX) becomes a future target of the development of the catalytic cracking technology. The domestic paraxylene supply still cannot meet domestic needs for a long time in the future. It is estimated that 1075 million tons of p-xylene are still imported domestically in 2020. The annual gap of the supply and demand of paraxylene in the domestic market is still more than 740 ten thousand tons in the expected 2020-plus 2025 years. In recent years, the increase in the production of aromatic hydrocarbon products represented by paraxylene has been a direction of attention of those skilled in the art in catalytic cracking of a main secondary processing unit of an oil refinery.

Catalytic cracking is one of the important technical means for heavy oil conversion, and the contribution of domestic refinery catalytic diesel to the product diesel is more than 20%. Therefore, the optimization of the structure and operation of the catalytic cracking unit is one of the main methods for adjusting the product structure and reducing the delivery pressure of diesel oil.

The catalytic cracking unit uses a terminator technology, which is one of important means for adjusting reaction severity to meet product requirements, and 80% of domestic catalytic units use the technology. The terminating agent medium commonly used on the catalytic device comprises various components with different properties, such as crude gasoline, stable gasoline, acidic water, purified water, light sump oil, coking light oil and the like. The reaction severity of different parts of the riser can be effectively controlled by adjusting the injection position of the terminating agent and the using amount of the terminating agent, and beneficial chemical reactions are promoted, so that the property of the product is improved, and the selectivity of the product is improved.

US5954942A discloses a process using water or gasifiable hydrocarbons as a terminating medium. The terminating medium is injected into the back of the riser to enhance the conversion of heavy hydrocarbons and improve the product structure. The method gives the influence of different terminator dosages and terminator injection positions on product distribution under corresponding working conditions. However, this termination technique is silent as to the hydrocarbon composition of the product, and in particular as to the olefin content of the gasoline.

US5217602A discloses a method for improving the structure of a product by extremely cold termination. The method firstly leads the catalyst and the reaction oil gas out of the lifting pipe and then quickly separates, and the catalyst enters a stripping section to carry out extremely cold operation on the reaction oil gas. The method can inhibit secondary cracking and avoid energy consumption increase caused by extreme cold of the catalyst. However, the method only terminates the secondary cracking reaction directionally, and has little effect on oil product modification requiring the participation of a catalyst and the like.

CN1600832A discloses a method for reducing the olefin content of gasoline in the catalytic cracking process. The method takes a plurality of inert media and light petroleum hydrocarbons as termination media, and gives the influence of different injection positions and injection termination dosage on the catalytic process and product distribution. However, the light petroleum hydrocarbon termination medium disclosed by the method is gasoline fraction, has high content of easily-reacting components such as olefin and the like, can generate cracking reaction in the process of terminating the main reaction, and is difficult to control the coke growth and the like.

The technology of using the terminator technology to reduce the diesel load and simultaneously increasing the yield of high-quality aromatic hydrocarbon products is rarely reported.

Disclosure of Invention

The invention aims to overcome the defects that the method in the prior art can not reduce the diesel load and increase the yield of high-quality aromatic hydrocarbon products at the same time, and provides a hydrocarbon oil conversion method.

In order to achieve the above object, the present invention provides a method for converting hydrocarbon oil, comprising:

(1) carrying out catalytic cracking reaction on a hydrogenated catalytic diesel raw material and a catalyst in a first reaction zone to obtain a material flow I, wherein the first reaction zone contains a riser reactor;

(2) introducing a transalkylation agent and the material flow I into a second reaction zone for transalkylation reaction to obtain a material flow II;

(3) and separating the material flow II to obtain reaction oil gas and a spent catalyst.

Compared with the prior art, the method for converting the hydrocarbon oil provided by the invention has the advantages that the second reaction zone for the transalkylation reaction is arranged, and the catalytic cracking reaction and the transalkylation reaction of the hydrogenated catalytic diesel oil are carried out in a partitioning manner, so that firstly, the reduction effect of the hydrogenated catalytic diesel oil is obvious, the conversion rate of the hydrogenated catalytic diesel oil is high, and the treatment capacity of the hydrogenated diesel oil raw material can reach more than 70%; secondly, the aromatic hydrocarbon content in the gasoline in the obtained reaction oil gas is increased, and the octane number (RON) is increased by 0.2-2 units; thirdly, the diesel load can be reduced, and simultaneously the yield of high-quality aromatic hydrocarbon products can be increased, especially the yield of Paraxylene (PX) is obviously improved; fourthly, the introduced second reaction zone is beneficial to independently adjusting parameters such as catalyst inventory, reaction temperature and the like in the transalkylation reaction process, and the operation is more flexible; and fifthly, devices related to the method are all existing equipment, so that the reconstruction capital required by oil refining enterprises is less, the cost is low, and the effect is quick.

Drawings

FIG. 1 is a schematic view of a hydrocarbon oil conversion scheme of the present invention.

Description of the reference numerals

1-raw material 2-lifting steam 3-lifting pipe reactor

4-second reaction zone 5-transalkylation agent 6-settler

7-stripper 8-reaction oil gas 9-standby vertical pipe

10-circulation inclined pipe 11-regenerator 12-regenerator main air

13-cyclone separator 14-regeneration flue gas 15-external heat collector

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.

As previously mentioned, the present invention provides a process for the conversion of hydrocarbon oils, which process comprises:

The invention adopts a method of oil-gas relay zone-division conversion, in the first reaction zone, ring-opening cracking reaction of hydrogenation catalytic diesel raw material naphthenic rings mainly occurs, and the obtained material flow I contains a large amount of multi-methyl monocyclic aromatic hydrocarbon; in the second reaction zone, the transalkylation reaction between the multi-methyl monocyclic aromatic hydrocarbon and the methyl-deficient transalkylation agent mainly occurs, and high-value aromatic hydrocarbon products such as xylene with middle carbon number (C8) and the like are generated to the maximum extent.

In the invention, the spent catalyst is stripped by a stripper after the reaction is finished. The separation method and the separation apparatus described in the step (3) are not limited by the present invention, and separation can be performed using, for example, a settler.

According to the invention, the reaction oil gas obtained in step (3) can be further processed according to conventional methods in the field, for example, the reaction oil gas can enter a subsequent separation system to separate products such as liquefied gas, gasoline fraction, diesel oil fraction and the like.

Preferably, the second reaction zone contains a fluidized bed reactor.

In a preferred embodiment of the present invention, the method further comprises: introducing at least part of the spent catalyst into a regenerator for regeneration, and recycling the obtained regenerated catalyst to the first reaction zone to participate in the catalytic cracking reaction. In the preferred embodiment, the regeneration may be preceded by conventional treatments of settling and stripping the spent catalyst.

Preferably, the carbon content in the regenerated catalyst is from 0.01 to 0.1 wt%.

In a preferred embodiment of the present invention, the method further comprises: recycling the remaining portion of the spent catalyst to the second reaction zone to participate in the transalkylation reaction. Further preferably, in this preferred embodiment, the amount of spent catalyst recycled to the second reaction zone is from 5 to 20% by weight of the total amount of said spent catalyst obtained in step (3).

The invention has wider selection range of the types of the transalkylation agents; in order to obtain high quality aromatics, especially to increase the yield of para-xylene and xylene, preferably the transalkylation agent is selected from benzene and/or toluene.

Preferably, the weight ratio of the amount of said transalkylation agent to the hydrocarbon oil component introduced into the second reaction zone is (0.015-0.5): 1. in the present invention, the "hydrocarbon oil component introduced into the second reaction zone" refers to the sum of the hydrocatalytic diesel feedstock in step (1) and an optionally introduced gasoline fraction obtained by separating the reaction oil gas obtained in step (3).

In a preferred embodiment of the present invention, the method further comprises: and (4) separating the reaction oil gas obtained in the step (3) to obtain gasoline fraction and diesel oil fraction.

Further preferably, the method further comprises: introducing said gasoline fraction into said second reaction zone to participate in said transalkylation reaction with said transalkylation agent. By adopting the preferred scheme, the catalyst inventory and the reaction temperature of the second reaction zone are favorably regulated.

In a preferred embodiment of the present invention, the catalytic cracking reaction is performed under conditions satisfying: the reaction temperature is 450-650 ℃, the reaction pressure is 100-450KPa, and the weight ratio of the catalyst to the hydrogenation catalyst diesel oil raw material is (2-20): 1, the weight ratio of the water vapor to the hydrogenated catalytic diesel raw material is (0.01-0.5): 1, the reaction time is 0.1s-30 s.

More preferably, the conditions of the catalytic cracking reaction satisfy: the reaction temperature is 500-550 ℃, the reaction pressure is 100-300KPa, and the weight ratio of the catalyst to the hydrogenation catalyst diesel oil raw material is (3-10): 1, the weight ratio of the water vapor to the hydrogenated catalytic diesel raw material is (0.02-0.3): 1, the reaction time is 0.1s-10 s.

In the present invention, the steam is referred to as lift steam, and the hydrocatalytic diesel fuel feedstock is introduced into the first reaction zone under the action of the lift steam. The lift steam is a pre-lift medium well known to those skilled in the art, and the function of the lift steam is to accelerate the catalyst to rise, so that a plug flow of the catalyst with uniform density is formed at the bottom of the riser reactor. The amount of the lifting steam is known to those skilled in the art, and generally, the amount of the lifting steam is 1 to 30% by weight, preferably 2 to 15% by weight, based on the total amount of the hydrocarbon oil.

According to the invention, the catalyst can be a fresh catalyst, wherein the fresh catalyst refers to an unreacted catalyst, or can be a regenerated catalyst in a reaction system, and is preferably a regenerated catalyst in the reaction system. The fresh catalyst is preferably an acidic catalytic cracking catalyst with or without molecular sieves. The molecular sieve is preferably at least one of Y or HY type zeolite containing or not containing rare earth, ultrastable Y type zeolite containing or not containing rare earth, ZSM-5 series zeolite or high-silicon zeolite, beta zeolite and ferrierite with five-membered ring structure, and the catalyst is preferably an acidic catalytic cracking catalyst containing no molecular sieve, and is more preferably an amorphous silicon-aluminum catalyst.

Preferably, the transalkylation reaction is such that: the reaction temperature is 450-500 ℃, the reaction pressure is 100-300KPa, and the weight ratio of the catalyst to the hydrocarbon oil component introduced into the second reaction zone is (6-10): 1, the weight ratio of the amount of the water vapor to the hydrocarbon oil component introduced into the second reaction zone is (0.02-0.5): 1, the reaction time is 2s-12 s.

In the invention, the hydrogenated catalytic diesel oil raw material is not limited and can be catalytic diesel oil produced by any catalytic cracking unit; preferably, the hydrocatalytic diesel feedstock satisfies the following conditions: the density is less than or equal to 0.95g/cm³And/or a hydrogen content of not less than 10% by weight.

More preferably, the hydrocatalytic diesel feedstock meets the following conditions: the density is less than or equal to 0.92g/cm³And/or a hydrogen content of not less than 12% by weight.

Preferably, the initial boiling point of the gasoline fraction is 60-95 ℃ and the final boiling point is 180-205 ℃.

According to a particularly preferred embodiment of the present invention, the method for converting hydrocarbon oil comprises:

(1) carrying out catalytic cracking reaction on a hydrogenated catalytic diesel raw material and a catalyst in a first reaction zone to obtain a material flow I, wherein the first reaction zone contains a riser reactor; the first reaction zone contains a riser reactor;

(2) introducing a transalkylation agent and the material flow I into a second reaction zone for transalkylation reaction to obtain a material flow II; the second reaction zone contains a fluidized bed reactor;

(3) separating the material flow II to obtain reaction oil gas and a spent catalyst;

introducing at least part of the spent catalyst into a regenerator for regeneration, and recycling the obtained regenerated catalyst to the first reaction zone to participate in the catalytic cracking reaction;

recycling the remaining portion of the spent catalyst to the second reaction zone to participate in the transalkylation reaction.

The foregoing particularly preferred embodiment of the present invention will now be described in detail with reference to FIG. 1, wherein the process for converting hydrocarbon oil, as shown in FIG. 1, comprises:

(1) introducing a hydrogenated catalytic diesel raw material 1 into a riser reactor 3 in a first reaction zone under the action of a lifting steam 2, contacting with a catalyst, ascending, and carrying out a catalytic cracking reaction to obtain a material flow I;

(2) introducing a transalkylation agent 5 and the material flow I into a fluidized bed reactor in a second reaction zone 4 for transalkylation reaction to obtain a material flow II;

(3) introducing the material flow II into a settler 6 for separation to obtain reaction oil gas 8 and a spent catalyst;

introducing at least part of the spent catalyst into a regenerator 11 for regeneration through a stripper 7 and a spent riser 9 in sequence, and recycling the obtained regenerated catalyst to the first reaction zone to participate in the catalytic cracking reaction;

the rest part of the spent catalyst is recycled to the second reaction zone 4 through a circulating inclined tube 10 to participate in the transalkylation reaction; the amount of spent catalyst recycled to the second reaction zone 4 is 5 to 20 wt% of the total amount of spent catalyst obtained in step (3);

and (4) separating the reaction oil gas 8 obtained in the step (3) to obtain a gasoline fraction and a diesel fraction, wherein the initial boiling point of the gasoline fraction is 60-95 ℃, and the final boiling point is 180-205 ℃. Optionally introducing said gasoline fraction into said second reaction zone to participate in said transalkylation reaction with said transalkylation agent.

The bottom of the regenerator 11 is provided with a regenerator main air 12, and the regenerator main air 12 is used for conveying main air into the regenerator 11; the cyclone separator 13 is arranged on the side surface inside the regenerator 11, and the cyclone separator 13 is used for settling and separating the catalyst to be regenerated in the regenerator 11 again to obtain regenerated flue gas 14 and the regenerated catalyst; an external heat collector 15 is arranged on the side surface of the regenerator 11.

In the invention, the first reaction zone and the second reaction zone are configured in series, and share one settler, a stripper and a regenerator.

In the present invention, the regenerator, the settler, the cyclone separator and the external heat exchanger are all common devices in the field, and the present invention is not limited thereto, as long as the corresponding functions can be realized, and thus, the details are not described herein.

In the invention, the stripping medium in the stripper is preferably stripped by adopting water vapor, and the effect of the stripping medium is to replace oil gas filled between catalyst particles and in particle pores, thereby improving the yield of oil products. The amount of steam used for stripping is well known to those skilled in the art. Generally, the amount of steam used for stripping is from 0.1 to 0.8% by weight, preferably from 0.2 to 0.4% by weight, based on the amount of catalyst circulated.

The present invention will be described in detail below by way of examples. In the following examples, the starting materials were all commercially available materials unless otherwise specified.

Wherein, the raw materials: hydrocatalytic diesel, purchased from Yanshan division of the China petrochemical group company, with properties listed in Table 2;

catalyst: CGP-YS catalyst, purchased from China petrochemical catalyst division, with properties as shown in Table 1;

a transalkylation agent: toluene.

In the following examples, a riser reactor with a second reaction zone of expanded diameter cylindrical configuration with a diameter of 100 mm was used.

In the following comparative examples, a medium-sized riser reactor having a cylindrical structure with a total height of 10 m and a diameter of 25 mm was used.

The composition of the reaction oil or gas or gasoline described in the examples below was determined using a gas chromatograph.

Example 1

This example is intended to illustrate the process for the catalytic conversion of hydrocarbon oils according to the invention.

As shown in figure 1, (1) preheated hydrocatalytic diesel raw material 1 is introduced into a riser reactor 3 in a first reaction zone under the action of lifting steam 2, contacts with a fresh CGP-YS catalyst, moves upwards, and undergoes catalytic cracking reaction to obtain a material flow I;

(3) introducing the material flow II into a settler 6 for separation to obtain reaction oil gas 8 and a spent catalyst; the carbon content in the spent catalyst is 1.12 wt%;

introducing part of the spent catalyst into a regenerator 11 for regeneration through a stripper 7 and a spent riser 9 in sequence, and recycling the obtained regenerated catalyst to the first reaction zone to participate in the catalytic cracking reaction; the carbon content in the regenerated catalyst is 0.1 wt%;

the rest of the spent catalyst is recycled to the second reaction zone 4 through a recycling inclined tube 10 to participate in the transalkylation reaction. The amount of the spent catalyst recycled to the second reaction zone 4 accounts for 10% by weight of the total amount of the spent catalyst obtained in step (3).

And (4) separating the reaction oil gas obtained in the step (3) to obtain a gasoline fraction and a diesel fraction, wherein the distillation range of the gasoline fraction is 71-202 ℃.

The process parameters involved in this example are shown in table 3. The product distribution of the reaction oil gas is shown in table 4, and the composition of gasoline in the reaction oil gas is shown in table 5.

Comparative example 1

Introducing a hydrogenated catalytic diesel raw material 1a preheated at 200 ℃ into the bottom of a medium-sized riser reactor under the action of pre-lifting steam, mixing the hydrogenated catalytic diesel raw material with a regenerated catalyst or a fresh catalyst for reaction, then enabling the hydrogenated catalytic diesel raw material to flow upwards to an outlet of the medium-sized riser reactor and enter a settler, and separating the mixture by a cyclone separator to obtain a spent catalyst and a reaction product; wherein the reaction temperature of the medium-sized riser reactor is 502 ℃ and the pressure is 140 kPa; the dosage of the pre-lifting steam is 5 wt% of the raw oil, the catalyst-oil ratio (weight ratio of the catalyst to the raw oil) is 6, and the retention time (namely reaction time) of the raw oil in the medium-sized riser reactor is 4 seconds.

And the reaction product enters a subsequent separation system to be separated to obtain product oil, the catalyst with carbon is stripped to obtain a spent catalyst, and the spent catalyst enters a regenerator to be burned and regenerated at 670 ℃ and then recycled.

The process parameters involved in this example are shown in table 3. The product distribution of the product oil obtained is shown in table 4, and the composition of the gasoline in said product oil is shown in table 5.

Example 2

Hydrocarbon oil conversion was carried out according to the method of example 1, except that the feedstock of the second reaction zone was a mixture of stream I, toluene and a gasoline fraction, the gasoline fraction was a portion of the gasoline fraction obtained by separating the reaction oil gas obtained in step (3) with a separation system, and the portion of the gasoline fraction was 50 wt% of the hydrocatalytic diesel feedstock; and the hydrocatalytic diesel oil is: gasoline fraction: the weight ratio of toluene is 10: 5: 1.

examples 3 to 5

Hydrocarbon oil conversion was carried out in the same manner as in example 1 except that the process parameters shown in Table 3 were used in place of those of example 1.

TABLE 1

TABLE 2

TABLE 3

Note: the pre-lifting steam amount of the riser reactor refers to the weight part of steam relative to 100 weight parts of hydrocatalytic diesel raw material, and the pre-lifting steam amount of the second reaction zone refers to the weight part of steam relative to 100 weight parts of hydrocarbon oil component introduced into the second reaction zone; the riser reactor and the second reaction zone are respectively a riser reactor and a second reaction zone reactor; the riser reactor agent-oil ratio refers to the weight ratio of the dosage of the catalyst in the riser reactor to the dosage of the hydrogenation catalytic diesel raw material; the second reaction zone catalyst-to-oil ratio is the weight ratio of the amount of catalyst in the second reaction zone to the oil component introduced into the second reaction zone.

TABLE 4

TABLE 5

Gasoline composition, wt%	Example 1	Example 2	Comparative example 1	Example 3	Example 4	Example 5	Example 6
								N-alkanes	13.6	15.5	13.5	12.9	13.4	16.7	23.9
Isoalkanes	20.5	20.9	20.2	20.4	20.6	18.8	14.6
								Olefins	14.4	14.5	14.3	15.1	13.9	12.2	10.4
Cycloalkanes	16.6	15.0	16.4	16.5	16.7	18.9	20.3
								Aromatic hydrocarbons	34.9	34.1	35.6	35.1	35.4	33.4	30.8
Net yield of xylene, wt.%	15.3	16.1	8.6	15.6	16.2	12.3	9.1
								Net yield of p-xylene, wt.%	3.6	4.1	2.1	3.8	4.2	2.4	2.3
Octane number (xylene withdrawn), wt%	90.9	91.1	90.5	91.1	91.0	90.7	89.9

As can be seen from tables 3-5, by adopting the method provided by the invention and controlling the reaction temperature of the second reaction zone to be lower than the reaction temperature of the riser reactor, the modification effect of gasoline in the prepared reaction oil gas is more obvious, the yield of liquefied gas is improved by at least 0.1 percent, and the yield of other products is also improved.

It can be seen from table 5 that the method provided by the present invention, especially the second reaction zone, is used for the guided promotion of the transalkylation reaction between the low carbon number transalkylation agent aromatic hydrocarbon and the heavy aromatic hydrocarbon, so that the yields of the high value xylene and paraxylene in the gasoline in the reaction oil gas are significantly improved.

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 the conversion of hydrocarbon oils, characterized in that it comprises:

2. The process of claim 1 wherein the second reaction zone contains a fluidized bed reactor.

3. The method of claim 1 or 2, wherein the method further comprises: introducing at least part of the spent catalyst into a regenerator for regeneration, and recycling the obtained regenerated catalyst to the first reaction zone to participate in the catalytic cracking reaction;

4. The method of claim 3, wherein the method further comprises: recycling the remaining portion of the spent catalyst to the second reaction zone to participate in the transalkylation reaction.

5. The process according to claim 4, wherein the amount of spent catalyst recycled to the second reaction zone is 5 to 20% by weight of the total amount of spent catalyst obtained in step (3).

6. The process of any one of claims 1-5, wherein the transalkylation agent is selected from benzene and/or toluene.

7. The process of any of claims 1-6, wherein the weight ratio of the amount of said transalkylation agent to the hydrocarbon oil component introduced into the second reaction zone is (0.015-0.5): 1.

8. the method of any of claims 1-7, wherein the method further comprises: and (4) separating the reaction oil gas obtained in the step (3) to obtain gasoline fraction and diesel oil fraction.

9. The method of claim 8, wherein the method further comprises: introducing said gasoline fraction into said second reaction zone to participate in said transalkylation reaction with said transalkylation agent.

10. The process according to any one of claims 1 to 9, wherein the conditions of the catalytic cracking reaction are such that: the reaction temperature is 450-650 ℃, the reaction pressure is 100-450KPa, and the weight ratio of the catalyst to the hydrogenation catalyst diesel oil raw material is (2-20): 1, the weight ratio of the water vapor to the hydrogenated catalytic diesel raw material is (0.01-0.5): 1, the reaction time is 0.1s-30 s;

preferably, the conditions of the catalytic cracking reaction satisfy: the reaction temperature is 500-550 ℃, the reaction pressure is 100-300KPa, and the weight ratio of the catalyst to the hydrogenation catalyst diesel oil raw material is (3-10): 1, the weight ratio of the water vapor to the hydrogenated catalytic diesel raw material is (0.02-0.3): 1, the reaction time is 0.1s-10 s.

11. The process according to claim 9 or 10, wherein the transalkylation reaction is subject to the following conditions: the reaction temperature is 450-500 ℃, the reaction pressure is 100-300KPa, and the weight ratio of the catalyst to the hydrocarbon oil component introduced into the second reaction zone is (6-10): 1, the weight ratio of the amount of the water vapor to the hydrocarbon oil component introduced into the second reaction zone is (0.02-0.5): 1, the reaction time is 2s-12 s.

12. The process according to any one of claims 1-11, wherein the hydrocatalytic diesel feedstock meets the following conditions: the density is less than or equal to 0.95g/cm³And/or the hydrogen content is more than or equal to 10 wt%;

preferably, the hydrocatalytic diesel feedstock satisfies the following conditions: the density is less than or equal to 0.92g/cm³And/or a hydrogen content of not less than 12% by weight.

13. The process as claimed in any one of claims 9 to 12, wherein the initial boiling point of the gasoline fraction is from 60 ℃ to 95 ℃ and the final boiling point is from 180 ℃ to 205 ℃.