A catalytic cracking slurry oil hydrotreating process and treatment system

Abstract

The present invention provides a catalytic cracking slurry oil hydroprocessing process and treatment system. The treatment process comprises first separating the catalytic cracking slurry oil into a light fraction and a heavy fraction; the heavy fraction is reacted in a first hydrogenation reaction zone to produce a first stream; the light fraction and the first stream are reacted in a second hydrogenation reaction zone; and the second stream is separated to produce a hydrogenated slurry oil. The present invention also provides a catalytic slurry oil hydroprocessing system comprising a fractionation unit and a slurry oil hydrogenation unit. The fractionation unit is provided with a heating furnace and a fractionating tower, and the slurry oil 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

Technical Field

[0001] 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

[0002] Catalytic cracking slurry oil is a byproduct of the catalytic cracking process. my country's annual catalytic cracking processing capacity exceeds 150 million tons, with slurry oil production accounting for approximately 3% to 5% of the total, and slurry oil production is increasing annually. Currently, slurry oil is mostly used as boiler fuel or as a blending material for delayed coking, significantly reducing its utility. This is because slurry oil is rich in polycyclic aromatic hydrocarbons, making it a potential high-quality feedstock for the production of high-value-added chemical products such as carbon black, carbon fiber, and needle coke.

[0003] Needle coke is a type of petroleum coke with excellent properties, featuring a low thermal expansion coefficient, high particle density, low porosity, and easy graphitization. It is primarily used in high-power and ultra-high-power graphite electrodes and specialty carbon products used in electric furnace steelmaking. As a raw material for graphite electrodes, needle coke must have a low sulfur content. Due to its coking mechanism, the raw materials for needle coke production require a high aromatics content and low colloidal asphaltene and ash contents. Catalytic cracking slurry oil, which is almost entirely composed of aromatics with side chains, is the optimal material for needle coke production.

[0004] As crude oil becomes increasingly inferior and heavier, the sulfur content of catalytic cracking slurry is usually high, requiring hydrodesulfurization. While performing hydrodesulfurization on the catalytic cracking slurry, it is also necessary to ensure that the aromatics in the slurry are not overly saturated with hydrogen.

[0005] CN110628461A discloses a method for selective hydrodesulfurization of oil slurry to retain aromatics. The method uses ultrasonic-assisted centrifugation to remove catalyst particles from the oil slurry. Then, vacuum distillation and dual-solvent extraction are used to separate the colloids, asphaltenes, and residual catalyst powder in the oil slurry from the ideal components enriched in aromatics. This method is lengthy and difficult to apply on a large scale in industry. Summary of the Invention

[0006] Based on the above situation, the purpose of the present invention is to provide a catalytic cracking oil slurry hydroprocessing process and processing system, which can retain the aromatic hydrocarbons in the catalytic cracking oil slurry feedstock to a maximum extent while efficiently desulfurizing, especially retaining the three-ring and four-ring aromatic hydrocarbons in the feedstock to a maximum extent, thereby solving the problem that the existing catalytic cracking oil slurry hydroprocessing process cannot simultaneously take into account the two indicators of desulfurization and aromatic hydrocarbon retention.

[0007] The technical solution provided by the present invention includes the following aspects:

[0008] The present invention provides a catalytic cracking oil slurry hydrotreatment process, comprising the following steps:

[0009] (1) Catalytic cracking slurry is cut and separated to obtain light fraction and heavy fraction;

[0010] (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 stream;

[0011] (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.

[0012] 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.

[0013] Furthermore, as a specific embodiment, the catalytic cracking oil slurry is subjected to a solid removal purification treatment, and the solid removal purification treatment can adopt any of the existing solid removal purification methods in the art, such as filtration, and the filtration 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.

[0014] Furthermore, 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 to 0.7h -1 ; The hydrogen-to-oil volume ratio is 50-1000, preferably 200-500.

[0015] Furthermore, 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 to 1.6 hours -1 ; The hydrogen-to-oil volume ratio is 50-1000, preferably 200-500.

[0016] Furthermore, 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.

[0017] Furthermore, as a specific embodiment, the volume space velocity of the first hydrogenation reaction zone is 0.2 to 1.2 h lower than the volume space velocity of the second hydrogenation reaction zone. -1 , preferably 0.5 to 1.0 h -1 .

[0018] Furthermore, 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.

[0019] 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 to 5 wt%, and the content of nickel as oxide is 0.5 to 4.5 wt%. 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 silica, preferably alumina.

[0020] Furthermore, as a specific embodiment, the first hydrogenation reaction unit is further loaded with a hydrogenation protective agent and a hydrodemetallization catalyst. The hydrogenation protective agent, hydrodemetallization catalyst, and first hydrogenation catalyst are sequentially loaded in the direction of liquid phase flow. The hydrogenation protective agent and hydrodemetallization catalyst can be commercially available products or prepared according to methods known in the art. Specifically, the FZC series hydrogenation protective agent and hydrodemetallization catalyst developed by the Fushun Petrochemical Research Institute of Sinopec can be used.

[0021] 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 as oxide is 3 to 18 wt%, and the content of cobalt as oxide is 1 to 4 wt%; 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, preferably alumina.

[0022] Furthermore, as a specific embodiment, the separation in step (3) is gas-liquid separation, and the separated gas is purified and then pressurized as circulating hydrogen by a circulating hydrogen compressor and then enters the first hydrogenation reaction zone and the second hydrogenation reaction zone for use respectively; the circulating hydrogen compressor is configured to be multi-stage compression, the outlet of the first-stage compressor is connected to the second hydrogenation reaction zone, and the second hydrogenation reaction zone is kept running at a lower hydrogenation pressure, and the outlet of the multi-stage compressor is connected to the first hydrogenation reaction zone, and the first hydrogenation reaction zone is kept running at a higher hydrogenation pressure.

[0023] Furthermore, as a specific embodiment, 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 provided, 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.

[0024] Furthermore, as a specific embodiment, 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 provided, 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.

[0025] Furthermore, as a specific embodiment, 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.

[0026] 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.

[0027] 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, specifically at least one of a metal wire mesh, an inorganic membrane filter, a hollow fiber membrane filter, etc.

[0028] Furthermore, as a specific embodiment, the catalytic cracking slurry first enters the slurry desolidification purification unit for desolidification treatment. After purification, the slurry enters the vacuum distillation unit, is heated in the heating furnace, and enters the distillation tower to obtain light fraction and heavy fraction after separation.

[0029] Furthermore, as a specific embodiment, the heavy fraction obtained from the distillation tower enters the second hydrogenation reaction zone through a pipeline, and the first material stream is obtained after the reaction.

[0030] Furthermore, as a specific embodiment, the light fraction obtained from the fractionation tower and the first stream obtained from the first hydrogenation reaction zone enter the second hydrogenation reaction zone through a pipeline, and the second stream is obtained after the reaction.

[0031] Furthermore, as a specific embodiment, 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 connected to the first hydrogenation reaction zone and the second hydrogenation reaction zone respectively.

[0032] Compared with the prior art, the catalytic cracking oil slurry hydrotreatment process and treatment system provided by the present invention have the following advantages:

[0033] In the catalytic cracking slurry hydroprocessing process provided by the present invention, the purified slurry is fractionated, and then the light fraction and heavy fraction obtained by the fractionation are further hydroprocessed separately. 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 direct desulfurization path, 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: direct desulfurization and hydrogenation saturation desulfurization. While ensuring the desulfurization effect, five-ring and above aromatic hydrocarbons can be converted to three-ring and four-ring aromatic hydrocarbons by hydrogenation saturation to a certain extent. Through the above technology, the composition of aromatic hydrocarbons in the 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 method solves the problem in the prior art that when producing needle coke raw materials by hydrotreating the whole fraction of catalytic cracking slurry, both efficient desulfurization and maximum retention of tri- and tetra-ring aromatics in the raw materials cannot be achieved.

[0034] The catalytic cracking oil slurry hydroprocessing process provided by the present invention is provided with two hydrogenation reaction zones, and is flexible in operation. 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 aromatic hydrocarbons in the oil slurry to the greatest extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram of the catalytic cracking oil slurry hydrotreatment process provided by the present invention. DETAILED DESCRIPTION

[0036] 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. However, 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 of the claims.

[0037] Herein, the properties of the slurry oil raw materials used in the examples of the present invention and the comparative examples and the slurry oil after being purified by the desolidification purification unit are shown in Table 1.

[0038] The hydrogenation protective agent and hydrogenation demetallization agent used in the present invention are the FZC hydrogenation protective agent and FZC hydrogenation demetallization catalyst developed by the Fushun Petrochemical Research Institute of Sinopec. Specific properties of the first and second hydrogenation catalysts are shown in Table 2. The first and second hydrogenation catalysts can be prepared using existing hydrogenation catalyst preparation methods in the art, such as the method disclosed in CN101492612A.

[0039] Figure 1 The present invention provides a catalytic cracking oil slurry hydroprocessing process flow chart, the specific process is as follows: catalytic cracking oil slurry 1 enters the oil slurry solid removal purification unit 2, after treatment, the purified catalytic cracking oil slurry raw material 4 and the solid-containing concentrated oil slurry raw material 3 are obtained, the purified catalytic cracking oil slurry raw material 4 is heated by the heating furnace 5 and enters the distillation tower 6, after fractionation in the distillation tower, the gas 7, the light fraction 8, the heavy fraction 9 are obtained, the heavy fraction 9 and the new hydrogen 10 enter the first hydrogenation reaction zone 12, and are mixed with the hydrogenation protective agent and the hydrogenation demetallization agent loaded therein. The catalyst is contacted with the first hydrogenation catalyst to react, and the reaction product (first stream), light fraction 8 and new hydrogen 10 obtained after the reaction enter the second hydrogenation reaction zone 11, and contact with the second hydrogenation catalyst filled therein to react. The reaction effluent (second stream) obtained after the reaction enters the gas-liquid separator 13, and is separated by the gas-liquid separator 13 to obtain hydrogen-rich gas 14 and hydrogenated oil slurry 16. 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.

[0040] Example 1

[0041] use Figure 1 The process flow utilizes the catalytic cracking slurry described in Table 1 as the raw material. The cut temperature for the light and heavy fractions is 445°C. The reaction conditions for the first and second hydrogenation reaction zones are shown in Table 3. The properties of the first and second hydrogenation catalysts are shown in Table 2. The properties of the hydrogenated slurry obtained after the reaction are shown in Table 4.

[0042] Example 2

[0043] use Figure 1 The process flow utilizes the catalytic cracking slurry described in Table 1 as the raw material. The cut temperature for the light and heavy fractions is 425°C. The reaction conditions for the first and second hydrogenation reaction zones are shown in Table 3. The properties of the first and second hydrogenation catalysts are shown in Table 2. The properties of the hydrogenated slurry obtained after the reaction are shown in Table 4.

[0044] Example 3

[0045] use Figure 1 The process flow utilizes the catalytic cracking slurry described in Table 1 as the raw material. The cut temperature for the light and heavy fractions is 445°C. The reaction conditions for the first and second hydrogenation reaction zones are shown in Table 3. The properties of the first and second hydrogenation catalysts are shown in Table 2. The properties of the hydrogenated slurry obtained after the reaction are shown in Table 4.

[0046] Comparative Example 1

[0047] Compared with Example 1, the difference is that the catalytic cracking slurry was not fractionated, and the whole fraction entered 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.

[0048] Comparative Example 2

[0049] The reaction conditions were similar to those in Example 1, except that the first hydrogenation catalyst was loaded in both the first and second hydrogenation reaction zones. Specific reaction conditions are shown in Table 5, and reaction results are shown in Table 6.

[0050] Comparative Example 3

[0051] The reaction conditions were similar to those in Example 2, except that the first and second hydrogenation reaction zones were both loaded with a second hydrogenation catalyst. The specific reaction conditions are shown in Table 5, and the reaction results are shown in Table 6.

[0052] Comparative Example 4

[0053] 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.

[0054] Table 1 Properties of raw materials

[0055] project Slurry oil raw materials Purified slurry <![CDATA[Density / g·cm -3 > 1.1262 1.1253 Freezing point / ℃ 21 20 Carbon residue / % 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 <![CDATA[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

[0056] Table 2 Catalyst properties

[0057]

[0058]

[0059] Table 3 Example reaction conditions

[0060] project Example 1 Example 2 Example 3 First hydrogenation reaction zone Pressure / MPa 6 6 5 Reaction temperature / ℃ 335 345 345 <![CDATA[Air speed / 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 <![CDATA[Air speed / h -1 > 1.2 1.2 1.2 Hydrogen-to-oil volume ratio 400 400 400

[0061] Table 4 Example reaction results

[0062] project Example 1 Example 2 Example 3 Hydrotreated oil 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 aromatic hydrocarbons, wt% 51.8 51.5 51.0

[0063] Table 5 Comparative Example Reaction Conditions

[0064]

[0065]

[0066] Table 6 Comparative Example Reaction Results

[0067] project Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Hydrotreated oil 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 aromatic hydrocarbons, wt% 49.7 47.5 50.5 50.8

[0068] 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 hydrocarbon composition in the slurry oil to the greatest extent, meeting the requirements for the production 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; in, The first hydrogenation reaction zone is loaded with a first 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 the group consisting of aluminum oxide and silicon oxide; 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 lower than that of the second hydrogenation reaction zone. -1 ; 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.

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 slurry oil hydrotreatment process according to claim 1, characterized in that: 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 ; The volume ratio of hydrogen to oil is 50~1000.

5. The catalytic cracking slurry oil hydrotreatment 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 ; The volume ratio of hydrogen to oil is 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 ; The volume ratio of hydrogen to oil is 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 ; The volume ratio of hydrogen to oil is 200~500.

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

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

10. The catalytic cracking slurry oil hydrotreating process according to claim 1, characterized in that: The reaction temperature of the first hydrogenation reaction zone is 50 to 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, characterized in that: The carrier of the first hydrogenation catalyst is alumina.

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

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

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