CN118685204B

CN118685204B - A catalytic cracking slurry oil hydrotreating process and treatment system

Info

Publication number: CN118685204B
Application number: CN202310294277.9A
Authority: CN
Inventors: 王超; 张庆军; 宋永一; 周维; 刘继华
Original assignee: Sinopec Dalian Petrochemical Research Institute Co ltd; China Petroleum and Chemical Corp
Current assignee: Sinopec Dalian Petrochemical Research Institute Co ltd; China Petroleum and Chemical Corp
Priority date: 2023-03-24
Filing date: 2023-03-24
Publication date: 2025-09-05
Anticipated expiration: 2043-03-24
Also published as: CN118685204A

Abstract

The invention provides a catalytic cracking slurry oil hydrotreating process and a treatment system, wherein the treatment process comprises the steps of firstly separating catalytic cracking slurry oil to obtain light fraction and heavy fraction, enabling the obtained heavy fraction to enter a first hydrogenation reaction zone for reaction to obtain a first material flow, enabling the obtained light fraction and the first material flow to enter a second hydrogenation reaction zone for reaction, and separating a second material flow obtained by reaction to obtain the hydrogenated slurry oil. The invention also provides a catalytic slurry oil hydrotreating system, which comprises a fractionating unit and a slurry oil hydrotreating unit, wherein the fractionating unit is provided with a heating furnace and a fractionating tower, and the slurry oil hydrotreating unit is provided with a first hydrogenation reaction zone, a second hydrogenation reaction zone, a gas-liquid separator and a circulating hydrogen compressor.

Description

Catalytic cracking slurry oil hydrotreating process and treatment system

Technical Field

The invention belongs to the field of petroleum processing, and particularly relates to a catalytic cracking slurry oil hydrogenation process and system.

Background

The catalytic cracking slurry oil is a byproduct produced in the catalytic cracking process, the annual processing amount of catalytic cracking in China exceeds 1.5 hundred million tons, the yield of the slurry oil accounts for about 3% -5% of the catalytic cracking processing amount, and the slurry oil yield is increased year by year. At present, the slurry oil is mostly used as the blending material of boiler fuel oil or delayed coking raw materials, and the utilization value of the slurry oil is seriously reduced, because the slurry oil is rich in polycyclic aromatic hydrocarbon, and can be used as a potential high-quality raw material for producing high-added-value chemical products such as carbon black, carbon fiber, needle coke and the like.

The needle coke is a petroleum coke with excellent performance, has the advantages of small thermal expansion coefficient, large particle density, small void ratio, easy graphitization and the like, and is mainly used for high-power and ultra-high-power graphite electrodes for electric furnace steelmaking and special carbon products. Needle coke, a raw material for graphite electrodes, must have a low sulfur content. According to the coking mechanism of needle coke, the raw materials for producing needle coke are required to have higher aromatic hydrocarbon content, lower colloid asphaltene content and ash content. The catalytic cracking slurry oil is almost aromatic hydrocarbon with side chains, and is the best material for producing needle coke.

As crude oil becomes progressively inferior and heavier, the sulfur content of the catalytic cracking slurry is generally higher and hydrodesulfurization treatment is required. The hydrodesulfurization is carried out on the catalytic cracking slurry oil, and meanwhile, the aromatic hydrocarbon in the slurry oil is ensured not to be excessively hydrogenated and saturated as much as possible.

CN110628461a discloses a method for selectively hydrodesulfurizing oil slurry to retain aromatic hydrocarbon, removing catalyst particles in the oil slurry by ultrasonic-assisted centrifugation, and then separating colloid, asphaltene and residual catalyst powder in the oil slurry from ideal components enriched with aromatic hydrocarbon by vacuum distillation and double-solvent extraction.

Disclosure of Invention

Based on the above circumstances, the invention aims to provide a catalytic cracking slurry oil hydrotreating process and a treatment system, wherein the hydrotreating process can be used for desulfurizing efficiently and simultaneously reserving aromatic hydrocarbons in a catalytic slurry oil raw material to the maximum extent, especially reserving tricyclic and tetracyclic aromatic hydrocarbons in the raw material to the maximum extent, so that the problem that two indexes of desulfurizing and reserving aromatic hydrocarbons cannot be simultaneously considered in the existing catalytic slurry oil hydrotreating process is solved.

The technical scheme provided by the invention comprises the following aspects:

the invention provides a catalytic cracking slurry oil hydrotreating process, which comprises the following steps:

(1) Cutting and separating the catalytic cracking slurry oil to obtain a light fraction and a heavy fraction;

(2) In the presence of hydrogen, the heavy fraction obtained in the step (1) enters a first hydrogenation reaction zone, and a first hydrogenation catalyst filled in the first hydrogenation reaction zone is contacted and reacts to obtain a first material flow;

(3) In the presence of hydrogen, the light fraction obtained in the step (1) and the first material flow obtained in the step (2) enter a second hydrogenation reaction zone to be contacted and reacted with a second hydrogenation catalyst filled in the second hydrogenation reaction zone, and the second material flow obtained by the reaction is separated to obtain hydrogenated slurry oil.

Further, as a specific embodiment, the cutting temperature of the light fraction and the heavy fraction in the step (1) is 410 to 470 ℃, preferably 430 to 450 ℃.

Further, as a specific embodiment, the catalytic cracking slurry is subjected to a solid removal and purification treatment, wherein the solid removal and purification treatment can be performed by any of the solid removal and purification methods existing in the art, such as filtration, a filtering device for purification can be at least one of a wire mesh, an inorganic membrane filter, a hollow fiber membrane filter and the like, and the solid content of the catalytic cracking slurry after the purification treatment is less than 50mg/L.

Further, as a specific embodiment, the first hydrogenation reaction zone is operated under the conditions that the reaction temperature is 200-450 ℃, preferably 320-390 ℃, the reaction pressure is 3.0-8.0 MPa, preferably 4.0-6.0 MPa, the volume space velocity is 0.2-1.0 h ^-1, preferably 0.3-0.7 h ^-1, and the hydrogen-oil volume ratio is 50-1000, preferably 200-500.

Further, as a specific embodiment, the second hydrogenation reaction zone is operated under the conditions that the reaction temperature is 100-350 ℃, preferably 200-300 ℃, the reaction pressure is 2.0-6.0 MPa, preferably 3.0-5.0 MPa, the volume space velocity is 0.5-2.0 h ^-1, preferably 0.8-1.6 h ^-1, and the hydrogen-oil volume ratio is 50-1000, preferably 200-500.

Further, as a specific embodiment, the reaction pressure in the first hydrogenation reaction zone is 1.0 to 4.0mpa, preferably 2.0 to 3.0mpa, higher than the reaction pressure in the second hydrogenation reaction zone.

Further, as a specific embodiment, the volume space velocity of the first hydrogenation reaction zone is 0.2-1.2 h ^-1, preferably 0.5-1.0 h ^-1 lower than the volume space velocity of the second hydrogenation reaction zone.

Further, as a specific embodiment, the reaction temperature of the first hydrogenation reaction zone is 20 to 150 ℃, preferably 50 to 100 ℃, higher than the reaction temperature of the second hydrogenation reaction zone.

Further, as a specific embodiment, the first hydrogenation catalyst loaded in the first hydrogenation reaction unit is a hydrogenation catalyst with active metal components of molybdenum and nickel, wherein the content of the molybdenum is 1-5wt% based on the weight of the first hydrogenation catalyst, the content of the nickel is 0.5-4.5wt% based on the weight of the first hydrogenation catalyst, the first hydrogenation catalyst comprises a carrier and the active metal components, and the carrier is at least one of inorganic refractory metal oxides such as alumina, silica and the like, preferably alumina.

Further, as a specific embodiment, the first hydrogenation reaction unit is further filled with a hydrogenation protecting agent and a hydrodemetallization catalyst, and the hydrogenation protecting agent, the hydrodemetallization catalyst and the first hydrogenation catalyst are sequentially filled according to the flowing direction of the liquid phase material. The hydrogenation protecting agent and the hydrodemetallization catalyst can be commercial products or can be prepared according to the method disclosed in the field, and specifically, FZC series hydrogenation protecting agents and hydrodemetallization catalysts developed by China petrochemical Co-Ltd and followed by the petrochemical institute can be adopted.

Further, as a specific embodiment, the second hydrogenation catalyst loaded in the second hydrogenation reaction unit is a hydrogenation catalyst with active metal components of molybdenum and cobalt, wherein the content of the molybdenum is 3-18wt% based on the weight of the second hydrogenation catalyst, and the content of the cobalt is 1-4wt% based on the weight of the second hydrogenation catalyst, the second hydrogenation catalyst comprises a carrier and an active metal component, and the carrier is at least one of inorganic refractory metal oxides such as alumina, silica and the like, and preferably alumina.

Further, as a specific implementation mode, the separation in the step (3) is gas-liquid separation, the gas obtained by separation is purified and then is used as circulating hydrogen to enter the first hydrogenation reaction zone and the second hydrogenation reaction zone respectively after being pressurized by a circulating hydrogen compressor, the circulating hydrogen compressor is arranged to be compressed in multiple stages, the outlet of the first compressor is communicated with the second hydrogenation reaction zone to keep the second hydrogenation reaction zone to operate under lower hydrogenation pressure, and the outlet of the multiple stages of compressors is communicated with the first hydrogenation reaction zone to keep the first hydrogenation reaction zone to operate under higher hydrogenation pressure.

Further, as a specific embodiment, the first hydrogenation reaction zone has no special requirement on the form and number of the reactors, and in general, the first hydrogenation reaction zone is provided with more than one hydrogenation reactor, when more than 2 hydrogenation reactors are provided, the reactors are connected in series and/or in parallel, preferably in series, and the hydrogenation reactors can be at least one of a fixed bed hydrogenation reactor, a fluidized bed hydrogenation reactor, a ebullated bed hydrogenation reactor and a suspended bed hydrogenation reactor, and preferably a fixed bed hydrogenation reactor is adopted.

Further, as a specific embodiment, the second hydrogenation reaction zone has no special requirement on the form and number of the reactors, and in general, the first hydrogenation reaction zone is provided with more than one hydrogenation reactor, when more than 2 hydrogenation reactors are provided, the reactors are connected in series and/or in parallel, preferably in series, and the hydrogenation reactors can be at least one of a fixed bed hydrogenation reactor, a fluidized bed hydrogenation reactor, a ebullated bed hydrogenation reactor and a suspended bed hydrogenation reactor, preferably a fixed bed hydrogenation reactor is adopted.

Further, as a specific embodiment, the sulfur content of the hydrogenated slurry oil obtained in the step (3) meets the requirement of the downstream needle coke raw material, and is generally not more than 0.5w%, the total aromatic hydrocarbon content is not more than 2 percent compared with the hydrogenation feeding loss rate, and the tricyclic and tetracyclic aromatic hydrocarbon contents are not more than 4 percent compared with the hydrogenation feeding loss rate.

The invention also provides a catalytic slurry oil hydrotreating system, which comprises a fractionating unit and a slurry oil hydrotreating unit, wherein the fractionating unit is provided with a heating furnace and a fractionating tower, and the slurry oil hydrotreating unit is provided with a first hydrogenation reaction zone, a second hydrogenation reaction zone, a gas-liquid separator and a circulating hydrogen compressor.

Further, as a specific embodiment, the catalytic slurry oil hydrotreatment system further includes a slurry oil removing and purifying unit, where the slurry oil removing and purifying unit adopts a filtering device, and specifically may adopt at least one of a wire mesh, an inorganic membrane filter, a hollow fiber membrane filter, and the like.

Further, as a specific implementation mode, the catalytic cracking slurry oil firstly enters a slurry oil removing and purifying unit for removing solid, the purified slurry oil enters a vacuum fractionation unit, is heated by a heating furnace and enters a fractionation tower for separation, and then light fraction and heavy fraction are obtained.

Further, as a specific embodiment, the heavy fraction obtained from the fractionating tower is fed into the second hydrogenation reaction zone through a pipeline, and the first stream is obtained after the reaction.

Further, as a specific embodiment, the light fraction obtained from the fractionating tower and the first stream obtained from the first hydrogenation reaction zone enter the second hydrogenation reaction zone through a pipeline, and a second stream is obtained after the reaction.

Further, as a specific implementation mode, a second material flow obtained in the second hydrogenation reaction zone enters a gas-liquid separator through a pipeline, gas and purified oil slurry are obtained after separation, and the separated gas is compressed by a circulating hydrogen compressor and then is communicated with the first hydrogenation reaction zone and the second hydrogenation reaction zone respectively.

Compared with the prior art, the catalytic cracking slurry oil hydrotreating process and the catalytic cracking slurry oil hydrotreating system provided by the invention have the advantages that:

In the catalytic cracking slurry oil hydrotreating process provided by the invention, the purified slurry oil is subjected to fractionation treatment, and then the light fraction and the heavy fraction obtained by fractionation are further subjected to hydrotreating respectively. The light fraction is treated under lower reaction pressure and reaction temperature and higher volume space velocity and matched with the molybdenum-cobalt hydrogenation catalyst, the desulfurization route of the light fraction component under the reaction condition is carried out more according to the direct desulfurization route, so that the hydrogenation saturation of aromatic hydrocarbon, especially tricyclic and tetracyclic aromatic hydrocarbon, in the light fraction component is avoided, the heavy fraction is hydrogenated under relatively higher reaction pressure and reaction temperature and lower volume space velocity and matched with the molybdenum-nickel hydrogenation catalyst, the desulfurization route of the heavy fraction component under the reaction condition can be carried out simultaneously according to the direct desulfurization route and the hydrogenation saturation desulfurization route, and the five-ring and above aromatic hydrocarbon can be converted into tricyclic and tetracyclic aromatic hydrocarbon to a certain degree while the desulfurization effect is ensured. Through the technology, the composition of aromatic hydrocarbon in the slurry oil, especially tricyclic and tetracyclic aromatic hydrocarbon can be reserved to the greatest extent, so as to meet the requirements of high-quality needle coke raw materials. Solves the problem that the prior art can not simultaneously realize high-efficiency desulfurization and maximum reservation of tricyclic and tetracyclic aromatic hydrocarbons in the raw materials when the needle coke raw materials are produced by the full-fraction hydrotreatment of the catalytic cracking slurry oil.

The catalytic cracking slurry oil hydrotreating process provided by the invention is provided with two hydrogenation reaction areas, is flexible to operate, can adjust operation in time when the slurry oil raw material property is changed, ensures the hydrofining effect, and simultaneously furthest retains the composition of aromatic hydrocarbon in the slurry oil.

Drawings

FIG. 1 is a schematic diagram of a catalytic cracking slurry hydroprocessing process flow provided by the invention.

Detailed Description

The following detailed description of the present application is provided by way of specific embodiments, and is provided by way of example with reference to the accompanying drawings, so as to ensure that a person skilled in the art can fully understand the technical scheme, but not so much so that the scope of the technical scheme of the present application is now defined by the claims.

Here, the slurry materials used in examples and comparative examples of the present invention are shown in Table 1 in terms of slurry properties after purification by a solid removal purification unit.

The hydrogenation protective agent and the hydrodemetallization agent used in the invention are FZC hydrogenation protective agents and FZC hydrodemetallization catalysts developed by China petrochemical industry Co-Ltd. The specific properties of the first hydrogenation catalyst and the second hydrogenation catalyst are shown in Table 2. The first hydrogenation catalyst and the second hydrogenation catalyst may be prepared by methods known in the art, such as those disclosed in patent CN101492612 a.

The catalytic cracking slurry oil 1 enters a slurry oil removal purification unit 2, a purified catalytic cracking slurry oil raw material 4 and a solid-containing concentrated slurry oil raw material 3 are obtained after treatment, the purified catalytic cracking slurry oil raw material 4 enters a fractionating tower 6 after being heated by a heating furnace 5, gas 7, light fraction 8 and heavy fraction 9 are obtained after fractionation by the fractionating tower, the heavy fraction 9 and new hydrogen 10 enter a first hydrogenation reaction zone 12 to be contacted with a hydrogenation protecting agent filled in the first hydrogenation reaction zone, a hydrogenation demetallization catalyst and the first hydrogenation catalyst for reaction, a reaction product (first material flow) obtained after the reaction, light fraction 8 and new hydrogen 10 enter a second hydrogenation reaction zone 11 to be contacted with a second hydrogenation catalyst filled in the second hydrogenation reaction zone for reaction, a reaction effluent (second material flow) obtained after the reaction enters a gas-liquid separator 13 to be separated to obtain hydrogen-rich gas 14 and hydrogenation slurry oil 16, and the hydrogen-rich gas 14 is circulated back to the first hydrogenation reaction zone and the second hydrogenation reaction zone after being pressurized by a circulating hydrogen compressor 15.

Example 1

The process flow described in fig. 1 was used, using the catalytic cracking slurry oil described in table 1 as a feedstock. Wherein the cleavage temperature of the light fraction and the heavy fraction is 445 ℃, and the reaction conditions of the first hydrogenation reaction zone and the second hydrogenation reaction zone are shown in table 3. Wherein the first hydrogenation catalyst and the second hydrogenation catalyst properties are shown in Table 2. The properties of the hydrogenated slurry obtained after the reaction are shown in Table 4.

Example 2

The process flow described in fig. 1 was used, using the catalytic cracking slurry oil described in table 1 as a feedstock. Wherein the cleavage temperature of the light fraction and the heavy fraction is 425 ℃, and the reaction conditions of the first hydrogenation reaction zone and the second hydrogenation reaction zone are shown in Table 3. Wherein the first hydrogenation catalyst and the second hydrogenation catalyst properties are shown in Table 2. The properties of the hydrogenated slurry obtained after the reaction are shown in Table 4.

Example 3

Comparative example 1

Compared with the example 1, the difference is that the catalytic cracking slurry oil is not fractionated, the whole fraction sequentially enters a first hydrogenation reaction zone and a second hydrogenation reaction zone for reaction, the specific reaction conditions are shown in Table 5, and the reaction results are shown in Table 6.

Comparative example 2

Substantially the same as in example 1, except that the first hydrogenation reaction zone and the second hydrogenation reaction zone were each filled with the first hydrogenation catalyst. The specific reaction conditions are shown in Table 5, and the reaction results are shown in Table 6.

Comparative example 3

Substantially the same as in example 2, except that the first hydrogenation reaction zone and the second hydrogenation reaction zone were each filled with the second hydrogenation catalyst. The specific reaction conditions are shown in Table 5, and the reaction results are shown in Table 6.

Comparative example 4

In contrast to example 3, the operating conditions of the first hydrogenation reaction zone and the second hydrogenation reaction zone were not designed in accordance with the principles of the present application. The specific reaction conditions are shown in Table 5, and the reaction results are shown in Table 6.

TABLE 1 Properties of the feedstock

Project	Slurry oil raw material	Purifying slurry oil
			Density/g.cm ^-3	1.1262	1.1253
Condensation point/° C	21	20
			Residual carbon/%	10.34	8.81
Ash/%	0.263	0.007
			Elemental composition
Carbon/hydrogen	89.51/7.26	90.05/7.24
			Sulfur/nitrogen	2.15/0.22	2.15/0.23
Solid content/mg.L ^-1	3250	42
			Total aromatic hydrocarbon	92.8	92.5
Monocyclic and bicyclic aromatic hydrocarbons	23.5	23.2
			Tricyclic and tetracyclic aromatic hydrocarbons	52.3	52.1

TABLE 2 catalyst Properties

TABLE 3 example reaction conditions

Project	Example 1	Example 2	Example 3
				First hydrogenation reaction zone
Pressure/MPa	6	6	5
				Reaction temperature/°c	335	345	345
Airspeed/h ^-1	0.42	0.45	0.42
				Hydrogen to oil volume ratio	500	500	500
Second hydrogenation reaction zone
				Pressure/MPa	4	4	5
Reaction temperature/°c	290	280	280
				Airspeed/h ^-1	1.2	1.2	1.2
Hydrogen to oil volume ratio	400	400	400

Table 4 example reaction results

Project	Example 1	Example 2	Example 3
				Hydrogenated slurry properties
Sulfur content/%	0.39	0.42	0.41
				Nitrogen content/%	0.18	0.19	0.18
Total aromatics (mass spectrum)/%	92.2	91.8	91.5
				Tricyclic and tetracyclic aromatics, wt%	51.8	51.5	51.0

Table 5 comparative example reaction conditions

Table 6 comparative example reaction results

Project	Comparative example 1	Comparative example 2	Comparative example 3	Comparative example 4
					Hydrogenated slurry properties
Sulfur content/%	0.56	0.36	0.38	0.68
					Nitrogen content/%	0.21	0.17	0.20	0.21
Total aromatics (mass spectrum)/%	89.2	84.8	87.8	90.2
					Tricyclic and tetracyclic aromatics, wt%	49.7	47.5	50.5	50.8

Through the description, the comparison analysis of the implementation cases and the comparison cases, the invention can realize the excellent desulfurization effect of the slurry oil hydrogenation, simultaneously reserve the aromatic hydrocarbon composition in the slurry oil to the greatest extent, and meet the production requirement of high-quality needle coke raw materials.

Claims

1. A catalytic cracking oil slurry hydrotreating process comprising the following steps:

(1) Catalytic cracking slurry is cut and separated to obtain light fraction and heavy fraction;

(2) In the presence of hydrogen, the heavy fraction obtained in step (1) enters a first hydrogenation reaction zone, where it contacts and reacts with a first hydrogenation catalyst loaded therein to obtain a first feed stream;

(3) In the presence of hydrogen, the light fraction obtained in step (1) and the first stream obtained in step (2) enter a second hydrogenation reaction zone, contact with a second hydrogenation catalyst loaded therein, and react. The second stream obtained by the reaction is separated to obtain a hydrogenated oil slurry;

The cutting temperature of the light fraction and the heavy fraction in step (1) is 410-470°C;

The first hydrogenation catalyst loaded in the first hydrogenation reaction zone is a hydrogenation catalyst having active metal components of molybdenum and nickel, wherein the molybdenum content as oxide is 1 to 5 wt%, and the nickel content as oxide is 0.5 to 4.5 wt%, based on the weight of the first hydrogenation catalyst; the first hydrogenation catalyst comprises a carrier and an active metal component, wherein the carrier is at least one of an inorganic refractory metal oxide selected from alumina and silica;

The second hydrogenation reaction zone is loaded with a second hydrogenation catalyst having active metal components of molybdenum and cobalt, wherein the molybdenum content as oxide is 3-18 wt%, and the cobalt content as oxide is 1-4 wt%, based on the weight of the second hydrogenation catalyst; the second hydrogenation catalyst comprises a carrier and an active metal component, wherein the carrier is at least one of an inorganic refractory metal oxide selected from the group consisting of aluminum oxide and silicon oxide;

The reaction pressure of the first hydrogenation reaction zone is 1.0-4.0 MPa higher than that of the second hydrogenation reaction zone; the volume space velocity of the first hydrogenation reaction zone is 0.2-1.2 h ^-1 lower than that of the second hydrogenation reaction zone; and the reaction temperature of the first hydrogenation reaction zone is 20-150° C. higher than that of the second hydrogenation reaction zone.

2. The catalytic cracking slurry oil hydrotreatment process according to claim 1, characterized in that the cutting temperature of the light fraction and the heavy fraction in step (1) is 430-450°C.

3. The catalytic cracking oil slurry hydrotreatment process according to claim 1, wherein the catalytic cracking oil slurry is subjected to a solid removal purification treatment, and the solid content of the catalytic cracking oil slurry after the purification treatment is less than 50 mg/L.

4. The catalytic cracking slurry oil hydrotreating process according to claim 1, characterized in that the operating conditions of the first hydrogenation reaction zone are: reaction temperature of 200-450°C; reaction pressure of 3.0-8.0 MPa; volume space velocity of 0.2-1.0 h ^-1 ; and hydrogen-to-oil volume ratio of 50-1000.

5. The catalytic cracking slurry oil hydrotreating process according to claim 1, characterized in that the operating conditions of the first hydrogenation reaction zone are: reaction temperature of 320-390°C; reaction pressure of 4.0-6.0 MPa; volume space velocity of 0.3-0.7 h ^-1 ; and hydrogen-to-oil volume ratio of 200-500.

6. The catalytic cracking slurry oil hydrotreating process according to claim 1, characterized in that the operating conditions of the second hydrogenation reaction zone are: reaction temperature of 100-350°C; reaction pressure of 2.0-6.0 MPa; volume space velocity of 0.5-2.0 h ^-1 ; and hydrogen-to-oil volume ratio of 50-1000.

7. The catalytic cracking slurry oil hydrotreating process according to claim 1, characterized in that the operating conditions of the second hydrogenation reaction zone are: reaction temperature of 200-300°C; reaction pressure of 3.0-5.0 MPa; volume space velocity of 0.8-1.6 h ^-1 ; and hydrogen-to-oil volume ratio of 200-500.

8. The catalytic cracking slurry oil hydrotreating process according to claim 1, wherein the reaction pressure in the first hydrogenation reaction zone is 2.0 to 3.0 MPa higher than the reaction pressure in the second hydrogenation reaction zone.

9. The catalytic cracking slurry oil hydrotreating process according to claim 1, wherein the volume space velocity of the first hydrogenation reaction zone is 0.5 to 1.0 h ^-1 lower than the volume space velocity of the second hydrogenation reaction zone.

10. The catalytic cracking slurry oil hydrotreating process according to claim 1, wherein the reaction temperature of the first hydrogenation reaction zone is 50-100°C higher than the reaction temperature of the second hydrogenation reaction zone.

11. The catalytic cracking slurry oil hydrotreating process according to claim 1, wherein the carrier of the first hydrogenation catalyst is alumina.

12. The catalytic cracking slurry oil hydrotreating process according to claim 1, characterized in that the first hydrogenation reaction zone is further filled with a hydrogenation protective agent and a hydrodemetallization catalyst, and the hydrogenation protective agent, the hydrodemetallization catalyst and the first hydrogenation catalyst are sequentially filled in the direction of flow of the liquid phase material.

13. The catalytic cracking slurry oil hydrotreating process according to claim 1, wherein the carrier of the second hydrogenation catalyst is alumina.

14. The catalytic cracking slurry oil hydrotreating process according to claim 1, characterized in that the separation in step (3) is gas-liquid separation, and the separated gas is purified and then pressurized by a circulating hydrogen compressor as circulating hydrogen and then enters the first hydrogenation reaction zone and the second hydrogenation reaction zone for use.

15. The catalytic cracking slurry oil hydrotreating process according to claim 1, characterized in that the sulfur content of the hydrogenated slurry oil obtained in step (3) is not more than 0.5w%, the total aromatic hydrocarbon content loss rate compared with the hydrogenation feed is not higher than 2 percentage points, and the three-ring and four-ring aromatic hydrocarbon content loss rate compared with the hydrogenation feed is not higher than 4 percentage points.