Method for hydrotreating catalytic gasoline and optimizing components in gasoline pool by using diesel oil

Abstract

The invention provides a method for catalyzing gasoline through diesel hydrotreatment and optimizing components in a gasoline pool, and provides a method for catalyzing gasoline impurities through diesel hydrotreatment, increasing catalytic reforming raw materials and optimizing the components in the gasoline pool. Diesel oil and diesel oil hydrogenated naphtha are generated; processing the residual part of the catalytic gasoline through an S-Zorb device to generate S-Zorb gasoline, and feeding the S-Zorb gasoline into a gasoline pool; the diesel hydrogenated naphtha is processed by a catalytic reforming device to generate reformed gasoline, and the reformed gasoline enters a gasoline pool. The catalytic gasoline is treated by a diesel hydrogenation process, so that the catalytic gasoline meets the feeding requirement of a catalytic reforming process, the feeding amount of the catalytic reforming process is increased, the yield of reformed gasoline is increased, the proportion of S-Zorb gasoline in a gasoline pool is reduced, the olefin content in the gasoline pool is reduced, the octane number in the gasoline pool is increased, and the purchase amount of alkylated oil is reduced; the gasoline blending cost is reduced, and the delivery requirements of high-grade gasoline are met.

Description

Technical Field

[0001] The invention belongs to the field of petrochemical industry, and in particular relates to a method for utilizing diesel hydrogenation to treat catalytic gasoline and optimize components in a gasoline pool. Background Art

[0002] With the improvement of gasoline environmental protection standards, the olefin content of gasoline is required to be reduced to less than 15v%, and the octane number is as high as 92, 95, etc. according to different grades, while the olefin content of catalytic gasoline is generally above 32v%, and the octane number is about 90. The ultra-low pressure continuous reforming process design uses straight-run naphtha (straight-run gasoline) and residual oil hydrogenated naphtha as raw materials. In the presence of hydrogen and catalyst, at a certain temperature and pressure, naphtha is converted into reformed gasoline rich in aromatics. Reformed gasoline contains almost no olefins, has high quality, good stability, and an octane number of more than 100.

[0003] The existing technology often uses the general product flow of atmospheric and vacuum distillation-residue oil hydrogenation-heavy oil catalytic cracking-S-Zorb, catalytic reforming, and diesel hydrogenation. Due to insufficient crude oil supply, the crude oil processing capacity of the atmospheric and vacuum distillation unit has been greatly reduced, resulting in low production of straight-run naphtha and residue oil hydrogenation naphtha, which limits the feed of the catalytic reforming process, and thus affects the production of reformed gasoline, causing the S-Zorb gasoline in the gasoline blending pool to be mismatched with the reformed gasoline, and the gasoline pool has a high olefin content and a low octane number, which affects the gasoline leaving the factory according to the grade. The original solution was to purchase high-octane, low-olefin gasoline blending components-alkylate from outside, and to increase the octane number of the components in the gasoline pool through forward blending, and the gasoline blending cost was relatively high.

[0004] Therefore, it is very necessary to propose a method of utilizing the existing equipment of the oil refining enterprise to increase the output of reformed gasoline and thus reduce the amount of purchased alkylate oil. Summary of the invention

[0005] The technical problem solved by the present invention is to provide a method for utilizing diesel hydrogenation to treat catalytic gasoline and optimize the components in the gasoline pool, thereby increasing the output of reformed gasoline, reducing the proportion of S-Zorb gasoline in the gasoline pool, reducing the olefin content in the gasoline pool, increasing the octane number in the gasoline pool, and reducing the gasoline blending cost.

[0006] In order to solve the above problems, the present invention provides a method for treating catalytic gasoline by diesel hydrotreating and optimizing the components in the gasoline pool, comprising the following steps:

[0007] S1. Crude oil is processed by atmospheric and vacuum distillation unit to produce atmospheric and vacuum residue oil, wax oil, atmospheric and vacuum diesel oil and straight-run naphtha;

[0008] S2. The atmospheric and vacuum residue oil and a portion of the wax oil are processed by a residue oil hydrogenation unit to generate residue oil hydrogenated heavy oil, residue oil hydrogenated diesel and residue oil hydrogenated naphtha; wherein the portion of the wax oil is specifically 28-35% of the total feed amount of the residue oil hydrogenation unit;

[0009] S3. The remaining part of the wax oil and the hydrogenated heavy oil residue are processed by a heavy oil catalytic cracking unit to generate catalytic gasoline and catalytic diesel;

[0010] S4. A portion of the catalytic gasoline is separated according to a preset amount and mixed with the atmospheric and vacuum diesel, the residual oil hydrogenated diesel and the catalytic diesel, and processed together by a diesel hydrogenation unit to generate diesel and diesel hydrogenated naphtha; the remaining portion of the catalytic gasoline is processed by an S-Zorb unit to generate S-Zorb gasoline, which enters the gasoline pool;

[0011] The diesel hydrogenation unit adopts conventional medium- and high-pressure trickle bed hydrogenation process, with a feed pressure of 8-10 MPa and a hydrogen-to-oil ratio of Nm 3 / m 3 ≥350:1;

[0012] S5. The straight-run naphtha, the residual oil hydrogenated naphtha and the diesel hydrogenated naphtha are firstly subjected to a naphtha pre-hydrogenation unit for pretreatment to remove impurities, and then processed by a catalytic reforming unit to generate pentane oil, C6 extract, reformed gasoline and mixed xylene, wherein the pentane oil, the reformed gasoline and the mixed xylene enter the gasoline pool;

[0013] The naphtha pre-hydrogenation unit and the catalytic reforming unit are a combined unit;

[0014] The catalytic reforming device adopts an ultra-low pressure continuous reforming process, and the catalyst adopts a platinum-rhenium dual-function catalyst.

[0015] Preferably, in S3, the operating conditions in the heavy oil catalytic cracking unit include: a reaction temperature of 500 to 520° C. and a reaction time of 1 to 4 seconds.

[0016] Preferably, in S4, the feed pressure of the diesel hydrotreating unit is 8.75 MPa.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention utilizes a diesel hydrogenation process to process catalytic gasoline, so that the catalytic gasoline meets the feed requirements of the catalytic reforming process, increases the feed amount of the catalytic reforming process, improves the output of reformed gasoline, reduces the proportion of S-Zorb gasoline in the gasoline pool, reduces the olefin content in the gasoline pool, improves the octane number in the gasoline pool, reduces the purchase amount of alkylate oil, reduces the gasoline blending cost, and meets the ex-factory requirements of high-grade gasoline;

[0019] 2. The present invention utilizes the existing equipment of the oil refining enterprise, comprehensively considers the distillation capacity of the diesel hydrotreating unit fractionation tower according to the reduction ratio of the crude oil processing volume, and reasonably controls the preset amount of separated catalytic gasoline entering the diesel hydrotreating unit for processing to meet the grade gasoline blending requirements, thereby improving the process flexibility of the existing equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a process flow chart of the method for utilizing diesel hydrogenation to treat catalytic gasoline and optimize components in a gasoline pool as described in Example 1 of the present invention. DETAILED DESCRIPTION

[0021] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solution of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] The present invention provides a method for treating catalytic gasoline by hydrogenating diesel and optimizing the components in a gasoline pool, comprising the following steps:

[0023] S1. Crude oil is processed by atmospheric and vacuum distillation unit to produce atmospheric and vacuum residue oil, wax oil, atmospheric and vacuum diesel oil and straight-run naphtha;

[0024] S2. The atmospheric and vacuum residue oil and a portion of the wax oil are processed by a residue oil hydrogenation unit to generate residue oil hydrogenated heavy oil, residue oil hydrogenated diesel and residue oil hydrogenated naphtha; wherein the portion of the wax oil is specifically 28-35% of the total feed amount of the residue oil hydrogenation unit;

[0025] S3. The remaining part of the wax oil and the hydrogenated heavy oil residue are processed by a heavy oil catalytic cracking unit to generate catalytic gasoline and catalytic diesel;

[0026] S4. A portion of the catalytic gasoline is separated according to a preset amount and mixed with the atmospheric and vacuum diesel, the residual oil hydrogenated diesel and the catalytic diesel, and processed together by a diesel hydrogenation unit to generate diesel and diesel hydrogenated naphtha; the remaining portion of the catalytic gasoline is processed by an S-Zorb unit to generate S-Zorb gasoline, which enters the gasoline pool;

[0027] The diesel hydrogenation unit adopts conventional medium- and high-pressure trickle bed hydrogenation process, with a feed pressure of 8-10 MPa and a hydrogen-to-oil ratio of Nm 3 / m 3 ≥350:1;

[0028] S5. The straight-run naphtha, the residual oil hydrogenated naphtha and the diesel hydrogenated naphtha are firstly subjected to a naphtha pre-hydrogenation unit for pretreatment to remove impurities, and then processed by a catalytic reforming unit to generate pentane oil, C6 extract, reformed gasoline and mixed xylene, wherein the pentane oil, the reformed gasoline and the mixed xylene enter the gasoline pool;

[0029] The naphtha pre-hydrogenation unit and the catalytic reforming unit are a combined unit;

[0030] The catalytic reforming device adopts an ultra-low pressure continuous reforming process, and the catalyst adopts a platinum-rhenium dual-function catalyst.

[0031] In the existing technology of oil refining enterprises, all catalytic gasoline passes through the S-Zorb device to generate S-Zorb gasoline, and the catalytic reforming feed is straight-run naphtha and residual oil hydrogenated naphtha. When the crude oil supply is normal, the ratio of S-Zorb gasoline and reformed gasoline in the gasoline pool can meet the ex-factory requirements of high-grade gasoline; when the crude oil supply is insufficient, the crude oil processing volume of the atmospheric and vacuum distillation unit is greatly reduced, resulting in low output of straight-run naphtha and residual oil hydrogenated naphtha, insufficient catalytic reforming feed, and low output of reformed gasoline. As a result, the proportion of S-Zorb gasoline in the gasoline pool is as high as more than 50%, the olefin content is high, the octane number is low, and the high-grade gasoline is difficult to blend. It can only be solved by increasing the purchase of high-octane blending components-alkylation oil, which increases the blending cost of gasoline.

[0032] Based on the existing process, the present invention separates a part of the catalytic gasoline according to a preset amount and enters the diesel hydrogenation device, and the remaining part of the catalytic gasoline enters the S-Zorb device according to the original process to generate S-Zorb gasoline. The catalytic gasoline is treated with the diesel hydrogenation process to make the catalytic gasoline meet the feed requirements of the catalytic reforming process, increase the feed amount of the catalytic reforming process, increase the output of reformed gasoline, reduce the proportion of S-Zorb gasoline in the gasoline pool, reduce the olefin content in the gasoline pool, increase the octane number in the gasoline pool, reduce the purchase amount of alkylate oil, reduce the gasoline blending cost, and meet the ex-factory requirements of high-grade gasoline. The specific implementation principle is as follows:

[0033] A naphtha pre-hydrogenation device is provided in front of the catalytic reforming device described in S5 of the present invention, which is used for pre-treatment of the catalytic reforming feed for impurity removal. The naphtha pre-hydrogenation device and the catalytic reforming device are a combined device. The catalytic reforming adopts an ultra-low pressure continuous reforming process, and the reaction conditions are relatively harsh, ultra-low pressure, high temperature, low hydrogen-to-oil ratio, RON104, and the designed feed is straight-run naphtha, residual oil hydrogenated naphtha and diesel hydrogenated naphtha. The reforming reaction catalyst adopts a platinum-rhenium bifunctional catalyst, which is very expensive and has strict requirements on the impurities of the feed, especially requiring the S content of the reaction feed to be ≤0.5ppm and the N content to be ≤0.5ppm. Because sulfides will be converted into H2S under reforming conditions and adsorbed on metal platinum, inhibiting the hydrogenation and dehydrogenation functions of the reaction catalyst, which is not conducive to reforming dehydrogenation and cyclization reactions; and the removal of organic nitrogen compounds is much more difficult than desulfurization under naphtha pre-hydrogenation conditions. Once the nitrogen compounds enter the reforming reactor, they will be converted into NH3 and further combined with chloride ions in the reforming circulating hydrogen to form ammonium chloride, reducing the chlorine content of the reforming catalyst, which strongly inhibits the acidic function of the reforming reaction catalyst and is not conducive to isomerization. Therefore, it is necessary to ensure that the sulfur and nitrogen content of the reforming hydrogenation reaction feed meets the requirements.

[0034] In the prior art, when the catalytic reforming feed is straight-run naphtha and residual oil hydrogenated naphtha, the naphtha pre-hydrogenation unit can remove impurities from the two feeds to make them meet the catalytic reforming feed requirements.

[0035] The heavy oil catalytic cracking unit described in S3 of the present invention is fed with the remaining part of the wax oil generated by the atmospheric and vacuum distillation process in S1 and the residual oil hydrogenated heavy oil generated by the residual oil hydrogenation process in S2. The generated catalytic gasoline has an olefin content of about 32% (V), a total S content of about 230-550ppm, an N content of about 126ppm, and an octane number of about 90. However, the naphtha pre-hydrogenation reaction pressure is 2.5MPa, which cannot make the catalytic gasoline denitrification meet the requirements. Therefore, the catalytic gasoline cannot be directly used as the feed of the catalytic reforming unit, and more stringent reaction conditions must be used to remove the nitrogen compounds.

[0036] Preferably, the heavy oil catalytic cracking reaction temperature is 500-520°C, and the reaction time is 1 to 4 seconds. More preferably, the reaction temperature is 510°C, and the reaction time is 2 seconds.

[0037] The diesel hydrogenation unit described in S4 adopts the conventional medium-high pressure trickle bed hydrogenation process, with a feed pressure of 8-10MPa and a hydrogen-to-oil ratio of Nm 3 / m 3 ≥350:1, high hydrogen partial pressure, capable of removing sulfur-containing compounds and nitrogen-containing compounds in catalytic gasoline, and can remove sulfur and nitrogen compounds to below 0.5ppm, making catalytic gasoline meet the feed conditions for catalytic reforming reaction.

[0038] Preferably, the feed pressure of the diesel hydrotreating unit is 8.75 MPa.

[0039] In the present invention, S4 divides the catalytic gasoline into two parts, separates a part according to a preset amount, mixes it with the atmospheric and vacuum diesel generated in S1, the residual oil hydrogenated diesel generated in S2, and the catalytic diesel generated in S3, and enters the diesel hydrogenation device together; removes sulfur and nitrogen compounds through a refining reaction, and then passes through the fractionation part of diesel hydrogenation to separate diesel and diesel hydrogenated naphtha with sulfur and nitrogen contents less than 0.5ppm. Among them, diesel is collected as a finished product and enters the storage and sales link; after the diesel hydrogenated naphtha has the feeding conditions for the catalytic reforming reaction, it first enters the naphtha pre-hydrogenation device for impurity removal pretreatment, and then is processed by the catalytic reforming device to generate pentane oil, C6 extract, reformed gasoline and mixed xylene. Among them, pentane oil, reformed gasoline and mixed xylene enter the gasoline pool. The C6 extract enters the benzene extraction device of the next process for processing to generate benzene and residual oil, which does not participate in the blending of the gasoline pool and is not described here. The remaining part of the catalytic gasoline maintains the original process, passes through the S-Zorb device, undergoes adsorption desulfurization and refines, and enters the gasoline pool after desulfurization.

[0040] The method for determining the preset amount is as follows: the amount of reformed gasoline required is calculated based on the olefin content and octane number in the gasoline pool, the distillation capacity of the diesel hydrotreating unit fractionation tower is comprehensively considered, the output of diesel hydrotreating naphtha is deduced, and then the amount of catalytic gasoline entering the catalytic hydrogenation unit in S4 is determined.

[0041] The reformed gasoline produced after catalytic reforming reaction-fractionation has the characteristics of octane number as high as RON104-108 and olefin content as low as 0.2% (V). After the catalytic gasoline is processed by the S-Zorb device, the S-Zorb gasoline obtained has only greatly reduced sulfur content compared to the feed catalytic gasoline, and the olefin and octane number are slightly reduced (negligible change), the olefin is still as high as 32% (V), and the octane number is about RON90.

[0042] In summary, the present invention increases the yield of reformed gasoline, reduces the proportion of S-Zorb gasoline in the gasoline pool, reduces the olefin content in the gasoline pool, increases the octane number in the gasoline pool, reduces the purchase amount of alkylated oil, reduces the gasoline pool blending cost, and meets the high-grade gasoline ex-factory requirements. The gasoline production standards of the present invention are 92# / 95# National VI / Beijing VI, National VI ethanol / Beijing VI ethanol, and 98# National VI.

[0043] At the same time, the present invention utilizes the existing equipment of the oil refining enterprise, and reasonably controls the preset amount of catalytic gasoline separated from S4 and entered into the diesel hydrogenation unit for processing according to the reduction ratio of the crude oil processing amount, so as to meet the grade gasoline blending requirements. For example, when the crude oil supply is sufficient, the catalytic reforming feed supply is sufficient, and the ratio of the generated reformed gasoline and S-Zorb gasoline in the gasoline pool is appropriate, which can meet the gasoline delivery requirements, then the catalytic gasoline in S4 only needs to enter the S-Zorb unit for processing to generate S-Zorb gasoline according to the original process; when the crude oil supply is insufficient, and the crude oil processing amount of the atmospheric and vacuum straight distillation process is reduced to different proportions, the amount of reformed gasoline required is calculated according to the olefin content and octane number in the gasoline pool, and the fractionation capacity of the diesel hydrogenation unit fractionation tower is comprehensively considered to deduce the output of diesel hydrogenation naphtha, and then determine the amount of catalytic gasoline entering the catalytic hydrogenation unit in S4 to meet the high-grade gasoline blending requirements. The process flexibility of the existing equipment is improved.

[0044] Example 1

[0045] like Figure 1 As shown, a process flow chart of a method of utilizing diesel hydrogenation to treat catalytic gasoline and optimize the components in the gasoline pool of this embodiment, the components involved in the gasoline pool blending are S-Zorb gasoline, pentane oil, reformed gasoline, mixed xylene, MTBE and purchased alkylate oil, MTBE is methyl tert-butyl ether, an anti-knock agent, which can be purchased or synthesized by the enterprise itself. The processing equipment includes: 10 million tons / year atmospheric and vacuum distillation unit, 3.4 million tons / year residual oil hydrogenation unit, (1.2+1.6) million tons / year heavy oil catalytic cracking unit, 1.2 million tons / year S-Zorb unit, 1.3 million tons / year catalytic reforming unit and 2.2 million tons / year diesel hydrogenation unit. The processing method steps are as follows:

[0046] S1. Crude oil is processed by atmospheric and vacuum distillation unit to produce atmospheric and vacuum residue oil, wax oil, atmospheric and vacuum diesel oil and straight-run naphtha;

[0047] S2. A portion of the atmospheric and vacuum residue and wax oil is processed by a residue hydrogenation unit to generate residue hydrogenated heavy oil, residue hydrogenated diesel and residue hydrogenated naphtha; a portion of the wax oil is specifically 30% of the total feed amount of the residue hydrogenation unit;

[0048] S3. The remaining part of the wax oil and the residual oil hydrogenated heavy oil are processed in a heavy oil catalytic cracking unit to produce catalytic gasoline and catalytic diesel; the reaction temperature is 510°C and the reaction time is 2 seconds.

[0049] S4 catalytic gasoline is separated at a rate of 20 tons / hour, mixed with atmospheric and vacuum diesel, residual oil hydrogenated diesel and catalytic diesel, and processed together by a diesel hydrogenation unit to generate diesel and diesel hydrogenated naphtha; the remaining portion of the catalytic gasoline is processed by an S-Zorb unit to generate S-Zorb gasoline and enter the gasoline pool;

[0050] The diesel hydrogenation unit adopts conventional medium- and high-pressure trickle bed hydrogenation process, with a reaction feed pressure of 8.75Mpa and a hydrogen-to-oil ratio of Nm 3 / m 3 =350:1;

[0051] S5. Straight-run naphtha, residue hydrotreated naphtha and diesel hydrotreated naphtha are first processed by a naphtha pre-hydrogenation unit for impurity removal pretreatment, with a reaction pressure of 2.5MPa. They are then processed by a catalytic reforming unit to generate pentane oil, C6 extract, reformed gasoline and mixed xylene. Among them, pentane oil, reformed gasoline and mixed xylene enter the gasoline pool; the C6 extract enters the next process benzene extraction unit for processing to generate benzene and raffinate oil, which does not participate in the blending of the gasoline pool;

[0052] The catalytic reforming unit adopts an ultra-low pressure continuous reforming process, and the catalyst uses a platinum-rhenium bifunctional catalyst.

[0053] In this embodiment, the output of the atmospheric and vacuum distillation unit is reduced to 56% of the designed output, and the two sets of heavy oil catalytic cracking units are at full load. In S4, catalytic gasoline is separated at a rate of 20 tons / hour, mixed with atmospheric and vacuum diesel, residual oil hydrogenated diesel and catalytic diesel, and enters the 2.2 million tons / year diesel hydrogenation unit together. After high hydrogen partial pressure refining treatment, sulfur and nitrogen are removed to 0.4ppm, and fractionated at the top of the diesel hydrogenation fractionation tower. After adding 18 tons / hour of diesel hydrogenated naphtha, it enters the naphtha pre-hydrogenation unit as the additional feed, and then enters the catalytic reforming reaction part, which can increase the reformed gasoline output by 15 tons / hour. The components of the gasoline pool are shown in Table 1.

[0054] Table 1

[0055]

[0056] Comparative Example

[0057] In S4 of this comparative example, all the catalytic gasoline enters the S-Zorb unit for processing to generate S-Zorb gasoline, and does not enter the diesel hydrogenation unit for processing. The feed of the catalytic reforming process is straight-run naphtha and residual oil hydrogenated naphtha. The remaining steps are the same as those in Example 1. The gasoline pool components are shown in Table 2.

[0058] Table 2

[0059]

[0060]

[0061] It can be seen from the results in Tables 1 and 2 that, without any additional engineering investment, the refinery reduced the proportion of S-Zorb gasoline in the gasoline pool of the entire plant from 52% to 48%, increased the proportion of reformed gasoline from 13% to 18%, reduced the proportion of purchased alkylate from 16% to less than 10%, reduced the proportion of olefins in the gasoline blending pool from 17.4% to 16.51%, and increased the octane number from 92.64 to 92.85, thus reducing the gasoline blending cost and ensuring that the gasoline can be shipped smoothly according to specifications.

[0062] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A method for treating catalytic gasoline by hydrogenating diesel and optimizing the components in the gasoline pool, characterized in that: The steps include: S1. Crude oil is processed by a normal and low pressure distillation unit to produce normal and low pressure residue oil, wax oil, normal and low pressure diesel oil and straight run naphtha; S2. The atmospheric and vacuum residue oil and a portion of the wax oil are processed by a residue oil hydrogenation unit to generate residue oil hydrogenated heavy oil, residue oil hydrogenated diesel and residue oil hydrogenated naphtha; wherein the portion of the wax oil is specifically 28-35% of the total feed amount of the residue oil hydrogenation unit; S3. The remaining part of the wax oil and the hydrogenated heavy oil residue are processed by a heavy oil catalytic cracking unit to generate catalytic gasoline and catalytic diesel; S4. A portion of the catalytic gasoline is separated according to a preset amount and mixed with the atmospheric and vacuum diesel, the residual oil hydrogenated diesel and the catalytic diesel, and processed together by a diesel hydrogenation unit to generate diesel and diesel hydrogenated naphtha; the remaining portion of the catalytic gasoline is processed by an S-Zorb unit to generate S-Zorb gasoline, which enters the gasoline pool; The diesel hydrogenation unit adopts conventional medium- and high-pressure trickle bed hydrogenation process, with a feed pressure of 8-10 MPa and a hydrogen-to-oil ratio of Nm 3 / m 3 ≥350:1; S5. The straight-run naphtha, the residual oil hydrogenated naphtha and the diesel hydrogenated naphtha are firstly subjected to a naphtha pre-hydrogenation unit for pretreatment to remove impurities, and then processed by a catalytic reforming unit to generate pentane oil, C6 extract, reformed gasoline and mixed xylene; wherein the pentane oil, the reformed gasoline and the mixed xylene enter the gasoline pool; The naphtha pre-hydrogenation unit and the catalytic reforming unit are a combined unit; The catalytic reforming device adopts an ultra-low pressure continuous reforming process, and the catalyst adopts a platinum-rhenium dual-function catalyst.

2. The method for utilizing diesel fuel to hydrotreat catalytic gasoline and optimize the components in the gasoline pool according to claim 1, characterized in that: In S3, the operating conditions in the heavy oil catalytic cracking unit include: a reaction temperature of 500 to 520° C. and a reaction time of 1 to 4 seconds.

3. The method for utilizing diesel fuel to hydrotreat catalytic gasoline and optimize the components in the gasoline pool according to claim 1, characterized in that: In S4, the feed pressure of the diesel hydrotreating unit is 8.75 MPa.

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