CN118685204A - A catalytic cracking oil slurry hydroprocessing process and processing system - Google Patents

Abstract

The present invention provides a catalytic cracking oil slurry hydroprocessing process and treatment system, wherein the treatment process is to first separate the catalytic cracking oil slurry to obtain a light fraction and a heavy fraction; the obtained heavy fraction enters a first hydrogenation reaction zone for reaction to obtain a first stream; the obtained light fraction and the first stream enter a second hydrogenation reaction zone for reaction, and the second stream obtained by the reaction is separated to obtain a hydrogenated oil slurry. The present invention also provides a catalytic oil slurry hydroprocessing system, comprising a fractionation unit and an oil slurry hydrogenation unit, wherein the fractionation unit is provided with a heating furnace and a fractionation tower, and the oil slurry hydrogenation unit is provided with a first hydrogenation reaction zone, a second hydrogenation reaction zone, a gas-liquid separator and a circulating hydrogen compressor.

Description

A catalytic cracking oil slurry hydroprocessing process and processing system

Technical Field

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

Background Art

Catalytic cracking slurry oil is a by-product produced in the catalytic cracking process. The annual processing volume of catalytic cracking in my country exceeds 150 million tons, and the output of slurry oil accounts for about 3% to 5% of the catalytic cracking processing volume. The output of slurry oil is increasing year by year. At present, slurry oil is mostly used as a blending material for boiler fuel oil or delayed coking raw materials, which seriously reduces the utilization value of slurry oil. This is because slurry oil is rich in polycyclic aromatic hydrocarbons and can be used as a potential high-quality raw material for the production of high-value-added chemical products such as carbon black, carbon fiber and needle coke.

Needle coke is a kind of petroleum coke with excellent performance. It has the advantages of small thermal expansion coefficient, large particle density, small porosity, easy graphitization, etc. It is mainly used for high-power and ultra-high-power graphite electrodes and special carbon products for electric furnace steelmaking. Needle coke, as the raw material of graphite electrode, 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 a high aromatic content, low colloidal asphaltene content and ash content. Catalytic cracking slurry is almost all aromatics with side chains, which is the best material for producing needle coke.

As crude oil becomes increasingly inferior and heavier, the sulfur content of catalytic cracking slurry is usually high and needs to be treated with hydrodesulfurization. While hydrodesulfurizing the catalytic cracking slurry, it is also necessary to ensure that the aromatics in the slurry are not overly saturated with hydrogen.

CN110628461A discloses a method for selective hydrodesulfurization of oil slurry to retain aromatics, wherein the catalyst particles in the oil slurry are removed by ultrasonic-assisted centrifugation, and then the colloid, asphaltenes and residual catalyst powder in the oil slurry are separated from the ideal components enriched in aromatics by vacuum distillation and dual solvent extraction. The method has a lengthy process and is difficult to be applied on a large scale in industry.

Summary of the invention

Based on the above situation, the purpose of the present invention is to provide a catalytic cracking oil slurry hydroprocessing process and a processing system, wherein the hydroprocessing process can retain the maximum amount of aromatics in the catalytic oil slurry feedstock while efficiently desulfurizing, especially retaining the maximum amount of tri-ring and tetra-ring aromatics in the feedstock, thereby solving the problem that the existing catalytic oil slurry hydroprocessing process cannot take into account both desulfurization and aromatics retention at the same time.

The technical solution provided by the present invention includes the following aspects:

The present invention provides a catalytic cracking oil slurry hydroprocessing process, comprising the following steps:

(1) The catalytic cracking slurry is cut and separated to obtain a light fraction and a 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.

Furthermore, as a specific embodiment, the cutting temperature of the light fraction and the heavy fraction in step (1) is 410-470°C, preferably 430-450°C.

Furthermore, as a specific implementation method, the catalytic cracking oil slurry is subjected to solid removal and purification treatment, and the solid removal and purification treatment can adopt any of the existing solid removal and purification methods in the art, such as filtration, and the filtering device used for purification can adopt at least one of a metal wire mesh, an inorganic membrane filter, a hollow fiber membrane filter, etc.; the solid content of the catalytic cracking oil slurry after purification treatment is less than 50 mg/L.

Further, as a specific embodiment, the operating conditions of the first hydrogenation reaction zone are: reaction temperature of 200-450°C, preferably 320-390°C; reaction pressure of 3.0-8.0 MPa, preferably 4.0-6.0 MPa; volume space velocity of 0.2-1.0 h ^-1 , preferably 0.3-0.7 h ^-1 ; hydrogen-to-oil volume ratio of 50-1000, preferably 200-500.

Further, as a specific embodiment, the operating conditions of the second hydrogenation reaction zone are: reaction temperature of 100-350°C, preferably 200-300°C; reaction pressure of 2.0-6.0 MPa, preferably 3.0-5.0 MPa; volume space velocity of 0.5-2.0 h ^-1 , preferably 0.8-1.6 h ^-1 ; hydrogen-to-oil volume ratio of 50-1000, preferably 200-500.

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

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

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

Furthermore, as a specific embodiment, the first hydrogenation catalyst loaded in the first hydrogenation reaction unit is a hydrogenation catalyst whose active metal components are molybdenum and nickel. Based on the weight of the first hydrogenation catalyst, the content of molybdenum as oxide is 1-5wt%, and the content of nickel as oxide is 0.5-4.5wt%; the first hydrogenation catalyst includes a carrier and an active metal component, and the carrier is at least one of inorganic refractory metal oxides such as alumina and silicon oxide, preferably alumina.

Further, as a specific embodiment, the first hydrogenation reaction unit is also loaded with a hydrogenation protective agent and a hydrodemetallization catalyst, and the hydrogenation protective agent, the hydrodemetallization catalyst and the first hydrogenation catalyst are loaded in sequence according to the flow direction of the liquid phase material. The hydrogenation protective agent and the hydrodemetallization catalyst can be commercially available products, or can be prepared according to methods disclosed in the art, and specifically, the FZC series hydrogenation protective agent and hydrodemetallization catalyst developed by Fushun Petrochemical Research Institute of Sinopec can be used.

Furthermore, as a specific embodiment, the second hydrogenation catalyst loaded in the second hydrogenation reaction unit is a hydrogenation catalyst whose active metal components are molybdenum and cobalt. Based on the weight of the second hydrogenation catalyst, the content of molybdenum in terms of oxide is 3-18wt%, and the content of cobalt in terms of oxide is 1-4wt%. The second hydrogenation catalyst includes a carrier and an active metal component, and the carrier is at least one of inorganic refractory metal oxides such as alumina and silica, and is preferably alumina.

Furthermore, as a specific implementation method, 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 before entering the first hydrogenation reaction zone and the second hydrogenation reaction zone for use; the circulating hydrogen compressor is configured to have multi-stage compression, the outlet of the first-stage compressor is connected to the second hydrogenation reaction zone to keep the second hydrogenation reaction zone running at a relatively low hydrogenation pressure, and the outlet of the multi-stage compressor is connected to the first hydrogenation reaction zone to keep the first hydrogenation reaction zone running at a relatively high hydrogenation pressure.

Furthermore, as a specific implementation, the first hydrogenation reaction zone has no special requirements on the form and number of reactors. Usually, the first hydrogenation reaction zone is equipped with more than one hydrogenation reactor. When more than two hydrogenation reactors are arranged, the reactors are connected in series and/or in parallel, preferably in series. The hydrogenation reactor can be at least one of a fixed bed hydrogenation reactor, a fluidized bed hydrogenation reactor, an ebullient bed hydrogenation reactor, and a suspended bed hydrogenation reactor, preferably a fixed bed hydrogenation reactor.

Furthermore, as a specific implementation, the second hydrogenation reaction zone has no special requirements on the form and number of reactors. Usually, the first hydrogenation reaction zone is equipped with more than one hydrogenation reactor. When more than two hydrogenation reactors are arranged, the reactors are connected in series and/or in parallel, preferably in series. The hydrogenation reactor can be at least one of a fixed bed hydrogenation reactor, a fluidized bed hydrogenation reactor, an ebullient bed hydrogenation reactor, and a suspended bed hydrogenation reactor, preferably a fixed bed hydrogenation reactor.

Furthermore, as a specific implementation method, the sulfur content of the hydrogenated oil slurry obtained in step (3) meets the requirements of the downstream needle coke feedstock, generally not more than 0.5w%, the total aromatics content loss rate compared to the hydrogenation feed is not higher than 2 percentage points, and the three-ring and four-ring aromatics content loss rate compared to the hydrogenation feed is not higher than 4 percentage points.

The present invention also provides a catalytic oil slurry hydroprocessing system, comprising a fractionation unit and an oil slurry hydrogenation unit, wherein the fractionation unit is provided with a heating furnace and a fractionation tower, and the oil slurry hydrogenation unit is provided with a first hydrogenation reaction zone, a second hydrogenation reaction zone, a gas-liquid separator and a circulating hydrogen compressor.

Furthermore, as a specific embodiment, the catalytic oil slurry hydroprocessing system also includes an oil slurry desolidification purification unit, and the oil slurry desolidification purification unit adopts a filtering device, which can specifically adopt at least one of a metal wire mesh, an inorganic membrane filter, a hollow fiber membrane filter, etc.

Furthermore, as a specific implementation method, the catalytic cracking oil slurry first enters the oil slurry desolidification purification unit for desolidification treatment, and the purified oil slurry enters the vacuum distillation unit, and after being heated by the heating furnace, enters the distillation tower to obtain light fraction and heavy fraction after separation.

Furthermore, as a specific implementation, the heavy fraction obtained from the distillation tower enters the second hydrogenation reaction zone through a pipeline, and the first feed stream is obtained after the reaction.

Furthermore, as a specific implementation, the light fraction obtained from the distillation 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 reaction.

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

Compared with the prior art, the catalytic cracking oil slurry hydroprocessing process and processing system provided by the present invention have the following advantages:

In the catalytic cracking oil slurry hydroprocessing process provided by the present invention, the purified oil slurry is fractionated, and then the light fraction and the heavy fraction obtained by the fractionation are further hydroprocessed respectively. The light fraction is treated at a lower reaction pressure and reaction temperature and a higher volume space velocity, and is matched with a molybdenum-cobalt type hydrogenation catalyst. The desulfurization path of the light fraction component under this reaction condition is more in accordance with the path of direct desulfurization, thereby avoiding the hydrogenation saturation of aromatic hydrocarbons, especially three-ring and four-ring aromatic hydrocarbons in the light fraction component; the heavy fraction is at a relatively high reaction pressure and reaction temperature and a lower volume space velocity, and is matched with a molybdenum-nickel type hydrogenation catalyst. The desulfurization path of the heavy fraction component under this reaction condition can be carried out simultaneously according to two paths of direct desulfurization and hydrogenation saturation desulfurization, which can ensure the desulfurization effect while converting five-ring and above aromatic hydrocarbons into three-ring and four-ring aromatic hydrocarbons to a certain extent through hydrogenation saturation. Through the above technology, the composition of aromatic hydrocarbons in the oil slurry can be retained to the greatest extent, especially the three-ring and four-ring aromatic hydrocarbons, to meet the requirements of high-quality needle coke raw materials. The invention solves the problem that in the prior art, when the whole fraction of catalytic cracking slurry is hydrotreated to produce needle coke raw materials, both efficient desulfurization and maximum retention of tri-ring and tetra-ring aromatics in the raw materials cannot be taken into account.

The catalytic cracking oil slurry hydroprocessing process provided by the present invention is provided with two hydrogenation reaction zones, and the operation is flexible. When the properties of the oil slurry raw material change, the operation can be adjusted in time to ensure the hydrorefining effect, while retaining the composition of aromatics in the oil slurry to the greatest extent.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of a catalytic cracking oil slurry hydroprocessing process provided by the present invention.

DETAILED DESCRIPTION

The technical solution of the present application is described in detail below through specific embodiments and in combination with the accompanying drawings to ensure that those skilled in the art can fully understand the technical solution, but this does not limit the protection scope of the technical solution of the present application. The specific protection scope shall be subject to the contents in the claims.

Herein, the properties of the slurry oil raw materials used in the embodiments of the present invention and the comparative examples and the slurry oil properties after being purified by the desolidification purification unit are shown in Table 1.

The hydrogenation protective agent and the hydrogenation demetallization agent used in the present invention are FZC hydrogenation protective agent and FZC hydrogenation demetallization catalyst developed by Fushun Petrochemical Research Institute of Sinopec. 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 can be prepared by the existing hydrogenation catalyst preparation method in the art, such as the method disclosed in patent CN101492612A.

FIG1 is a process flow chart of catalytic cracking oil slurry hydroprocessing provided by the present invention, and the specific process is as follows: catalytic cracking oil slurry 1 enters oil slurry desolidification purification unit 2, and after treatment, purified catalytic cracking oil slurry raw material 4 and solid-containing concentrated oil slurry raw material 3 are obtained, the purified catalytic cracking oil slurry raw material 4 is heated by a heating furnace 5 and enters a distillation tower 6, and after fractionation in the distillation tower, gas 7, light fraction 8, and heavy fraction 9 are obtained, and the heavy fraction 9 and new hydrogen 10 enter the first hydrogenation reaction zone 12, and react with the hydrogenation protective agent, hydrogenation desolidification agent, etc. filled therein. The metal catalyst contacts with the first hydrogenation catalyst for reaction. The reaction product (first stream), light fraction 8 and new hydrogen 10 obtained after the reaction enter the second hydrogenation reaction zone 11, contact with the second hydrogenation catalyst loaded therein for reaction. The reaction effluent (second stream) obtained after the reaction enters the gas-liquid separator 13, and hydrogen-rich gas 14 and hydrogenated oil slurry 16 are obtained after separation by the gas-liquid separator 13. The hydrogen-rich gas 14 is pressurized by the circulating hydrogen compressor 15 and circulated back to the first hydrogenation reaction zone and the second hydrogenation reaction zone.

Example 1

The process flow described in FIG1 is adopted, and the catalytic cracking slurry described in Table 1 is used as the raw material. The cutting temperature of the light fraction and the heavy fraction is 445° C. The reaction conditions of the first hydrogenation reaction zone and the second hydrogenation reaction zone are shown in Table 3. The properties of the first hydrogenation catalyst and the second hydrogenation catalyst 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 FIG1 is adopted, and the catalytic cracking slurry described in Table 1 is used as the raw material. The cutting temperature of the light fraction and the heavy fraction is 425° C. The reaction conditions of the first hydrogenation reaction zone and the second hydrogenation reaction zone are shown in Table 3. The properties of the first hydrogenation catalyst and the second hydrogenation catalyst are shown in Table 2. The properties of the hydrogenated slurry obtained after the reaction are shown in Table 4.

Example 3

The process flow described in FIG1 is adopted, and the catalytic cracking slurry described in Table 1 is used as the raw material. The cutting temperature of the light fraction and the heavy fraction is 445° C. The reaction conditions of the first hydrogenation reaction zone and the second hydrogenation reaction zone are shown in Table 3. The properties of the first hydrogenation catalyst and the second hydrogenation catalyst are shown in Table 2. The properties of the hydrogenated slurry obtained after the reaction are shown in Table 4.

Comparative Example 1

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

Comparative Example 2

The reaction conditions are basically the same as those in Example 1, except that the first hydrogenation reaction zone and the second hydrogenation reaction zone are both loaded 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

The reaction conditions are basically the same as those in Example 2, except that the first hydrogenation reaction zone and the second hydrogenation reaction zone are both loaded 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

Compared with Example 3, the difference is that the operating conditions of the first hydrogenation reaction zone and the second hydrogenation reaction zone are not designed according to the principles of this application. The specific reaction conditions are shown in Table 5, and the reaction results are shown in Table 6.

Table 1 Raw material properties

project Slurry oil raw materials Purification of slurry oil Density/g·cm ^-3 1.1262 1.1253 Pour point/℃ twenty one 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 aromatics 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 The first hydrogenation reaction zone Pressure/MPa 6 6 5 Reaction temperature/℃ 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/℃ 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 oil 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 aromatic hydrocarbons, 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 oil 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 aromatic hydrocarbons, wt% 49.7 47.5 50.5 50.8

Through the above description and comparative analysis of implementation cases and comparative cases, it is found that the present invention can achieve excellent desulfurization effect of slurry oil hydrogenation, while retaining the aromatic composition in the slurry oil to the greatest extent, meeting the requirements for the production of high-quality needle coke raw materials.

Claims (19)

1. A catalytic cracking slurry oil hydrotreating process 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.

2. The catalytic cracking slurry hydroprocessing process according to claim 1, characterized in that: the cutting temperature of the light fraction and the heavy fraction in the step (1) is 410 to 470 ℃, preferably 430 to 450 ℃.

3. The catalytic cracking slurry hydroprocessing process according to claim 1, characterized in that: the catalytic cracking slurry oil is subjected to solid removal and purification treatment, and the solid content of the catalytic cracking slurry oil after the purification treatment is less than 50mg/L.

4. The catalytic cracking slurry hydroprocessing process according to claim 1, characterized in that: the operating conditions of the first hydrogenation reaction zone are: 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 airspeed is 0.2-1.0 h ^-1, preferably 0.3-0.7 h ^-1; the volume ratio of the hydrogen oil is 50 to 1000, preferably 200 to 500.

5. The catalytic cracking slurry hydroprocessing process according to claim 1, characterized in that: the second hydrogenation reaction zone is operated under the following conditions: 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 airspeed is 0.5-2.0 h ^-1, preferably 0.8-1.6 h ^-1; the volume ratio of the hydrogen oil is 50 to 1000, preferably 200 to 500.

6. The catalytic cracking slurry hydroprocessing process according to claim 1, characterized in that: the reaction pressure in the first hydrogenation reaction zone is 1.0-4.0 MPa, preferably 2.0-3.0 MPa, higher than that in the second hydrogenation reaction zone.

7. The catalytic cracking slurry hydroprocessing process according to claim 1, characterized in that: 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.

8. The catalytic cracking slurry hydroprocessing process according to claim 1, characterized in that: the reaction temperature of the first hydrogenation reaction zone is 20-150 ℃, preferably 50-100 ℃, higher than the reaction temperature of the second hydrogenation reaction zone.

9. The catalytic cracking slurry hydroprocessing process according to claim 1, characterized in that: the first hydrogenation catalyst filled 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, and 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 an active metal component, wherein the carrier is at least one of inorganic refractory metal oxides such as alumina, silica and the like, and preferably alumina.

10. The catalytic cracking slurry hydroprocessing process according to claim 1, characterized in that: the first hydrogenation reaction unit is also filled with a hydrogenation protecting agent and a hydrogenation demetallization catalyst, and the hydrogenation protecting agent, the hydrogenation demetallization catalyst and the first hydrogenation catalyst are sequentially filled according to the flowing direction of the liquid phase material.

11. The catalytic cracking slurry hydroprocessing process according to claim 1, characterized in that: the second hydrogenation catalyst filled 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 3-18 wt% based on the weight of the second hydrogenation catalyst, and the content of the cobalt is 1-4 wt% based on the weight of the oxide; the second hydrogenation catalyst comprises a carrier and an active metal component, wherein the carrier is at least one of inorganic refractory metal oxides such as alumina, silica and the like, and preferably alumina.

12. The catalytic cracking slurry hydroprocessing process according to claim 1, characterized in that: the separation in the step (3) is gas-liquid separation, and the gas obtained by separation is purified and then is used as circulating hydrogen to enter a first hydrogenation reaction zone and a second hydrogenation reaction zone for use after being pressurized by a circulating hydrogen compressor.

13. The catalytic cracking slurry hydroprocessing process according to claim 1, characterized in that: the sulfur content of the hydrogenated slurry oil obtained in the step (3) is not more than 0.5 percent, 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.

14. A catalytic slurry oil hydrotreating system 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.

15. The catalytic cracking slurry hydroprocessing system according to claim 14, wherein: the catalytic slurry oil hydrotreatment system further comprises a slurry oil solid removal and purification unit, and the slurry oil solid removal and purification unit adopts a filtering device.

16. The catalytic cracking slurry hydroprocessing system according to claim 15, wherein: the catalytic cracking slurry oil firstly enters a slurry oil removing and purifying unit for removing solid, the purified slurry oil enters a decompression fractionating unit, and enters a fractionating tower after being heated by a heating furnace, and light fraction and heavy fraction are obtained after separation.

17. The catalytic cracking slurry hydroprocessing system according to claim 14, wherein: the heavy fraction obtained from the fractionating tower enters a second hydrogenation reaction zone through a pipeline, and a first material flow is obtained after the reaction.

18. The catalytic cracking slurry hydroprocessing system according to claim 14, wherein: the light fraction obtained by the fractionating tower and the first material flow obtained by the first hydrogenation reaction zone enter a second hydrogenation reaction zone through a pipeline, and a second material flow is obtained after the reaction.

19. The catalytic cracking slurry hydroprocessing system according to claim 14, wherein: a second material flow obtained in the second hydrogenation reaction zone enters a gas-liquid separator through a pipeline, and gas and purified oil slurry are obtained after separation; and the separated gas is compressed by a circulating hydrogen compressor and then is respectively communicated with the first hydrogenation reaction zone and the second hydrogenation reaction zone.