A combined process and system for heavy oil processing

Abstract

This invention discloses a combined process and system for heavy oil processing. The combined process includes the following steps: In the presence of hydrogen, heavy oil enters a fluidized bed hydrogenation unit. The reaction effluent is separated to obtain a first gaseous stream and a first liquid stream. The first gaseous stream is mixed with hydrogen and enters a first fixed bed hydrogenation reaction unit. The first liquid stream is mixed with hydrogen and enters a second fixed bed hydrogenation reaction unit. The reaction effluent is fractionated to obtain light hydrocarbons, hydrogenated naphtha, hydrogenated diesel, and hydrogenated residue. The hydrogenated residue enters a catalytic cracking unit. The reaction effluent is separated to obtain catalytic liquefied petroleum gas, catalytic naphtha, catalytic diesel, catalytic cycle oil, and catalytic slurry. This process can flexibly produce clean oil products, has a short process flow, a high degree of coupling between units, and low energy consumption and investment.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of petroleum chemical industry, and particularly relates to a combined process and system for deep processing of heavy oil through ebullated bed and fixed bed hydrogenation technology. BACKGROUND

[0002] Current refineries are in a critical period of transformation from "oil refining type" to "chemical type", and oil refining enterprises show the trend of "integration and scale". Whether it is a new refinery or an existing refinery upgrading, it is around how to adjust the product structure and convert more oil products into clean chemicals. Among them, heavy oil hydrogenation technology plays an important role in the transformation of oil refining structure. The current mature heavy oil hydrogenation technology mainly includes fixed bed hydrogenation technology and ebullated bed hydrogenation technology. With the year-by-year aggravation of the heavy and poor quality of processed crude oil, ebullated bed hydrogenation technology is increasingly valued, which is mainly due to the advantages of ebullated bed in residue lightening, such as strong adaptability to raw materials, long running period, flexible device operation, etc. It can adapt to poor quality heavy oil raw materials that are difficult to process by fixed bed, and has high conversion rate, which can convert more heavy components into light fractions.

[0003] However, the ebullated bed hydrogenation technology currently has a difficult problem in the field of residue conversion, i.e. the hydrogenation oil system has low stability at high conversion rate, and coking precursors are easily precipitated in the reaction and fractionation system. With the extension of running time, coke blocks are gradually formed, which affects the long-period stable operation of the device. Of course, the ebullated bed hydrogenation technology is not the highest in economic benefit when ensuring high conversion rate, and the running period needs to be considered. However, at a lower conversion rate, the heavier components in the residue oil are difficult to convert into light fractions, which will inevitably affect the conversion of heavy and poor quality residue oil into chemicals. At the same time, due to the full back-mixing mode of the ebullated bed hydrogenation system, the generated oil cannot meet the product index and needs to be further processed. However, the existing processing technology has low coupling degree with the ebullated bed device, and lacks integrated technology for combining ebullated bed hydrogenation with other hydrogenation processes or decarburization processes to realize efficient conversion of the device from poor quality residue oil to chemicals and clean oil products.

[0004] CN106947523A discloses a method for ebullated bed residue hydrocracking. The method includes two ebullated bed reactors in series, and a residue hydroprocessing catalyst and a residue hydrocracking catalyst are respectively used in the first and second ebullated bed reactors. The process and catalyst configuration scheme used in the invention result in poor product properties, and there is a problem that long-period operation at high conversion rate is difficult to ensure.

[0005] CN103102944A discloses a combined process method for residue oil hydroprocessing and lightening, residue oil and hydrogen are reacted in a first ebullated bed hydroconversion reactor system, then enter a fractionation system, vacuum residue enters a solvent deasphalting system to obtain deoiled asphalt and deasphalted oil, the deoiled asphalt and the deasphalted oil are respectively subjected to hydroprocessing, and the hydroprocessed oil enters the fractionation system again. In the invention, the increase of the ebullated bed hydroconversion rate will inevitably increase the coking risk, and the ebullated bed hydroprocessed oil and the deasphalted oil need to be processed by separate hydrogenation devices, the processing flow is relatively long, the integration degree is relatively low, and the energy consumption is high. SUMMARY

[0006] In view of the deficiencies in the prior art, the present application provides a heavy oil processing combined process and system. The process can flexibly produce clean oil products, and has a short process flow, high coupling degree of each unit, low energy consumption and low investment.

[0007] The first aspect of the present application provides a heavy oil processing combined process, which comprises the following contents:

[0008] (1) under the condition of hydrogen, heavy oil enters an ebullated bed hydrogenation unit, and the reaction effluent is separated to obtain a first gas phase stream and a first liquid phase stream;

[0009] (2) the first gas phase stream obtained in step (1) is mixed with hydrogen and enters a first fixed bed hydrogenation reaction unit, the reaction effluent is separated to obtain a second gas phase stream and a second liquid phase stream, and the second liquid phase stream is fractionated to obtain light hydrocarbon, naphtha and diesel products;

[0010] (3) the first liquid phase stream obtained in step (1) is mixed with hydrogen and enters a second fixed bed hydrogenation reaction unit, the reaction effluent is separated to obtain a third gas phase stream and a third liquid phase stream, and the third liquid phase stream is fractionated to obtain light hydrocarbon, hydrogenated naphtha, hydrogenated diesel and hydrogenated residue oil;

[0011] (4) the hydrogenated residue oil obtained in step (3) enters a catalytic cracking unit, and the reaction effluent is separated to obtain catalytic liquefied gas, catalytic naphtha, catalytic diesel, catalytic cycle oil and catalytic oil slurry.

[0012] In the above combined process, the heavy oil raw material in step (1) is at least one of atmospheric residue, vacuum residue and heavy asphalt.

[0013] In the above combined process, the ebullated bed hydrogenation unit in step (1) is provided with at least one ebullated bed reactor, and preferably one ebullated bed reactor; the ebullated bed reactor can be a reactor with a circulating cup, or a STRONG ebullated bed reactor with an internal three-phase separator developed by SINOPEC (Dalian) Petroleum Chemical Research Institute Co., Ltd.

[0014] In the combined process, the ebullated bed reactor in the ebullated bed hydrogenation unit in step (1) is loaded with an ebullated bed hydrogenation catalyst, which comprises a carrier and an active metal component, the active metal component being one or more of nickel, cobalt, molybdenum or tungsten; the carrier can be one or more of alumina, silica, alumina-silica or titania.

[0015] In the combined process, the first gas phase stream and the first liquid phase stream cutting point in step (1) is 280-350℃, and the separation of naphtha and diesel fraction into the first gas phase stream is controlled.

[0016] In the combined process, the operating conditions of the ebullated bed hydrogenation unit in step (1) are as follows: reaction temperature 350-450℃, preferably 360-410℃, reaction pressure 10.0-19.0 MPa, preferably 13.0-18.0 MPa, hydrogen / oil volume ratio 300-1000, preferably 400-600, liquid hourly space velocity 0.1-3.0 h -1 , preferably 0.3-1.0 h -1 .

[0017] In the combined process, at least one fixed bed hydrogenation reactor is provided in the first fixed bed hydrogenation reaction unit in step (2), and preferably a single fixed bed hydrogenation reactor is provided.

[0018] In the combined process, the first fixed bed hydrogenation reaction unit in step (2) comprises a hydrofining reaction zone and a hydrocracking reaction zone; the first gas phase stream is mixed with hydrogen and enters the hydrofining reaction zone, which generally has 1-3 hydrofining catalyst beds arranged along the liquid phase flow direction, and reacts with the hydrofining catalyst in the beds; the hydrofining reaction effluent enters the hydrocracking reaction zone, which generally has 1-3 hydrocracking catalyst beds arranged along the liquid phase flow direction, and reacts with the hydrocracking catalyst in the beds.

[0019] The hydrogenation refining catalyst comprises a carrier and active metals, wherein the active metals can be one or more of nickel, cobalt, molybdenum or tungsten; the carrier can be one or more of alumina, silica, alumina-silica, titania. The hydrogenation cracking catalyst comprises a carrier and active metals, wherein the active metals can be one or more of nickel, cobalt, molybdenum or tungsten; the carrier can be one or more of alumina, silica, alumina-silica, titania, molecular sieve; the hydrogenation refining catalyst and / or the hydrogenation cracking catalyst can be commercially available or prepared according to the existing disclosed method; in the present application, the hydrogenation refining catalyst can be FF-66 brand hydrogenation refining catalyst developed by SINOPEC (Dalian) Oil Chemical Research Institute, and the hydrogenation cracking catalyst can be FC-76 brand hydrogenation cracking catalyst developed by SINOPEC (Dalian) Oil Chemical Research Institute.

[0020] In the combined process, the naphtha dry point in step (2) is controlled to be not higher than 200℃, which can be used as a steam cracking ethylene raw material; the diesel can be used as a clean fuel to be exported or returned to the fixed-bed hydrogenation cracking unit for conversion.

[0021] In the combined process, the operating conditions of the first fixed-bed hydrogenation reaction unit in step (2) are as follows: the average reaction temperature is 340-390℃, preferably 350-380℃; the reaction pressure is 10.0-18.0 MPa, preferably 13.0-17.0 MPa; the inlet hydrogen / oil volume ratio is 800-2000, preferably 800-1500; the volume space velocity is 0.8-2.0 h -1 , preferably 1.0-1.5 h -1 .

[0022] In the combined process, the second fixed-bed hydrogenation reaction unit in step (3) is provided with at least 2 fixed-bed hydrogenation reactors, preferably 3-6 reactors, and further preferably 4-5 reactors in series; the second fixed-bed hydrogenation reactor is provided with 1-2 catalyst beds, preferably 1 catalyst bed.

[0023] In the combined process, the second fixed-bed hydrogenation reactor in step (3) is sequentially filled with a hydrogenation protection catalyst, a metal removal catalyst, a desulfurization catalyst and a residual carbon removal catalyst according to the liquid phase flow direction; the hydrogenation protection catalyst, the metal removal catalyst, the desulfurization catalyst and the residual carbon removal catalyst comprise a carrier and active metals, wherein the active metals can be one or more of nickel, cobalt, molybdenum or tungsten; the carrier can be one or more of alumina, silica, alumina-silica, titania. The hydrogenation protection catalyst, the metal removal catalyst, the desulfurization catalyst and the residual carbon removal catalyst can be commercially available or prepared according to the existing disclosed method.

[0024] In the combined process, the cutting point of the hydrogenated naphtha and the hydrogenated diesel in step (3) is 160-210°C, preferably 180-200°C.

[0025] In the combined process, the operating conditions of the second fixed-bed hydrogenation reaction unit in step (3) are as follows: the average reaction temperature is 340-430°C, preferably 350-410°C; the hydrogen to oil volume ratio at the inlet is 600-2000, preferably 800-1500; the volume space velocity is 0.1-1.5 h -1 , preferably 0.2-0.8 h -1 .

[0026] In the combined process, the catalytic cracking unit in step (4) is provided with at least one set of catalytic cracking device; the catalytic cracking device comprises a riser reactor, a settler, a regenerator and a cyclone separator; the operating conditions of the riser reactor are as follows: the reaction temperature is 500-780°C, preferably 550-700°C; the mass ratio of water vapor to feed is 0.05:1-1:1, preferably 0.10:1-0.5:1; the reaction pressure is 0.10-1.0 MPa, preferably 0.10-0.5 MPa; the contact time with the catalyst is 0.1-15.0 seconds, preferably 0.5-5.0 seconds.

[0027] In the combined process, the catalytic cracking catalyst used in the catalytic cracking device in step (4) comprises a zeolite, an inorganic oxide and optionally a clay; the zeolite is at least one selected from Y-type or HY-type zeolite with or without rare earth, ultra-stable Y-type zeolite, and zeolite with MFI structure.

[0028] In the combined process, the catalytic cracking device in step (4) preferably adopts a double riser process, and the naphtha obtained in step (2) can be used as the feed of the second riser.

[0029] In the combined process, the cutting point of the catalytic naphtha and the catalytic diesel in step (4) is 160-220°C, preferably 180-210°C; the cutting point of the catalytic diesel and the catalytic cycle oil is 310-370°C, preferably 330-350°C; the cutting point of the catalytic cycle oil and the catalytic oil slurry is 360-420°C, preferably 370-400°C.

[0030] In the combined process, the catalytic cycle oil in step (4) is partially or entirely recycled to the ebullated-bed hydrogenation unit.

[0031] In the combined process, the catalytic cycle oil in step (4) is partially recycled to the ebullated-bed hydrogenation unit; the catalytic cycle oil is divided into first catalytic cycle oil and second catalytic cycle oil, the first catalytic cycle oil is recycled to the ebullated-bed hydrogenation unit, and the second catalytic cycle oil is self-circulated in the catalytic cracking unit; the mass ratio of the first catalytic cycle oil to the second catalytic cycle oil is 1:5-5:1, preferably 1:1-3:1.

[0032] In the combined process, the catalytic oil slurry in step (4) is all or partially recycled to the ebullated-bed hydrogenation unit after being treated by desolidification.

[0033] In the combined process, the hydrogenated diesel oil obtained in step (3) and / or the catalytic diesel oil obtained in step (4) is recycled to the first fixed-bed hydrogenation reaction unit for treatment.

[0034] In the combined process, the second gas phase stream in step (2) and / or the third gas phase stream in step (3) is treated by cold high separation, hydrogen desulfurization and membrane separation; the hydrogen concentration in the hydrogen-rich gas obtained after the membrane separation treatment is above 95%, and the hydrogen-rich gas is recycled after being pressurized by a compressor.

[0035] In the combined process, the separation is a high-temperature and high-pressure separation mode, and in the present application, hot high separation is adopted; the hot high separation equipment adopts a vertical structure, and a hot hydrogen stripping pipeline is preferably additionally arranged.

[0036] The second aspect of the present application provides a heavy oil processing combined system, which comprises an ebullated-bed hydrogenation unit, a first high-temperature and high-pressure separation unit, a first fixed-bed hydrogenation reaction unit, a second high-temperature and high-pressure separation unit, a first fractionation unit, a second fixed-bed hydrogenation reaction unit, a third high-temperature and high-pressure separation unit, a second fractionation unit, a catalytic cracking unit and a third fractionation unit.

[0037] The ebullated-bed hydrogenation unit is used for receiving a heavy oil raw material and reacting with hydrogen;

[0038] The first high-temperature and high-pressure separation unit is used for receiving and separating the reaction effluent from the ebullated-bed hydrogenation unit, and obtaining a first gas phase stream and a first liquid phase stream after the separation;

[0039] The first fixed-bed hydrogenation reaction unit is used for receiving the first gas phase stream from the first high-temperature and high-pressure separation unit and reacting with hydrogen;

[0040] The second high-temperature and high-pressure separation unit is used for receiving and separating the reaction effluent from the first fixed-bed hydrogenation reaction unit, and obtaining a second gas phase stream and a second liquid phase stream after the separation;

[0041] a first fractionation unit for receiving and separating the second liquid phase stream from the second high temperature and high pressure separation unit to obtain light hydrocarbon, naphtha and diesel products;

[0042] a second fixed bed hydrogenation reaction unit for receiving the first liquid phase stream from the first high temperature and high pressure separation unit to react with hydrogen;

[0043] a third high temperature and high pressure separation unit for receiving the reaction effluent from the second fixed bed hydrogenation reaction unit to obtain a third gas phase stream and a third liquid phase stream;

[0044] a second fractionation unit for receiving the third liquid phase stream from the third high temperature and high pressure separation unit to obtain light hydrocarbon, hydrogenated naphtha, hydrogenated diesel and hydrogenated residual oil by fractionation;

[0045] a catalytic cracking unit for receiving the hydrogenated residual oil from the second fractionation unit to react with catalytic cracking catalyst;

[0046] a third fractionation unit for receiving the reaction effluent from the catalytic cracking unit to obtain catalytic liquefied gas, catalytic naphtha, catalytic diesel, catalytic cycle oil and catalytic slurry oil by fractionation.

[0047] In the above system, as a specific embodiment, the catalytic cycle oil obtained from the third fractionation unit is partially or entirely introduced into the ebullated bed hydrogenation unit through a pipeline.

[0048] In the above system, as a specific embodiment, the heavy oil hydrogenation system further comprises a recycle hydrogen unit for receiving the second gas phase stream from the second high temperature and high pressure separation unit and / or the third gas phase stream from the third high temperature and high pressure separation unit to be treated and recycled as recycle hydrogen to be used in each reaction unit; the recycle hydrogen unit generally comprises a desulfurization device, a membrane separation device and a recycle hydrogen compressor.

[0049] In the above system, as a specific embodiment, the ebullated bed hydrogenation unit is provided with at least one ebullated bed reactor, preferably one ebullated bed reactor; the ebullated bed reactor can be a reactor with a circulation cup or a STRONG ebullated bed reactor with an internal three-phase separator developed by SINOPEC (Dalian) Petroleum Chemical Research Institute Co., Ltd.

[0050] In the above system, as a specific embodiment, the first fixed bed hydrogenation reaction unit is provided with at least one fixed bed hydrogenation reactor, preferably one fixed bed hydrogenation reactor.

[0051] In the system, as a specific embodiment, the second fixed-bed hydrogenation reaction unit is provided with at least one fixed-bed hydrogenation reactor, preferably 3-5 reactors, and further preferably 4-5 reactors in series; and the second fixed-bed hydrogenation reactor is provided with 1-2 catalyst beds, preferably one catalyst bed.

[0052] In the system, as a specific embodiment, the catalytic slurry oil from the third fractionation unit is communicated with the ebullated-bed hydrogenation unit through a pipeline.

[0053] In the system, as a specific embodiment, the hydrogenated diesel oil from the second fractionation unit and / or the catalytic diesel oil from the third fractionation unit is communicated with the first fixed-bed hydrogenation reaction unit through a pipeline.

[0054] In the system, as a specific embodiment, each fractionation unit can be integrally arranged or separately arranged, preferably separately arranged.

[0055] Compared with the prior art, the combined process has the following advantages:

[0056] The present application makes full use of the advantages of the ebullated-bed hydrogenation in converting macromolecular asphaltene and removing heavy metals, provides high-quality feedstock for the fixed-bed hydrogenation unit, better plays the advantages of the fixed-bed in aromatic saturation and hydrofining, improves the feed quality of the catalytic cracking unit, and greatly prolongs the operation cycle of the unit.

[0057] The conventional ebullated-bed process separates the reaction effluent into naphtha, diesel oil, wax oil and unconverted oil, and has the following problems: 1. the hydrogenated oil system has low stability at high conversion rate, and coking precursors are easily precipitated in the reaction and fractionation system, resulting in coking; and 2. each fraction product is processed by a separate process, and the integration degree of the unit is not high. In the combined process, the heavy oil feedstock is subjected to ebullated-bed hydrogenation and then rapidly separated to obtain a first gas phase stream (light fraction) and a first liquid phase stream (heavy fraction), and the light and heavy fractions are processed by fixed-bed hydrogenation technology with different catalyst grading and reaction bed layer settings according to their property characteristics, which can effectively avoid the above problems.

[0058] In the present application, the first gas phase stream (light fraction) and the first liquid phase stream (heavy fraction) in the reaction effluent of the ebullated-bed hydrogenation unit are processed by fixed-bed hydrogenation technology with different catalyst grading and reaction bed layer settings according to their property characteristics. For the light fraction, which mainly contains diesel oil fraction (containing part of naphtha), a fixed-bed hydrofining-cracking system configuration can be used to realize the conversion of this fraction segment to chemical raw material naphtha.

[0059] 4、The present application ingeniously combines the hydrogenation technology and catalytic cracking technology, and circulates the catalytic cycle oil and catalytic oil slurry to the ebullated bed system. Based on the reaction dynamic balance mechanism, the main component of the catalytic cycle oil is heavy diesel oil, which is introduced into the ebullated bed reaction system, so that the conversion of heavy components to heavy diesel oil components can be effectively inhibited, and more conversion to naphtha, light diesel oil and wax oil fractions is provided, thereby providing better chemical raw materials; and the 2-4 ring aromatic hydrocarbons in the catalytic cycle oil partially act as hydrogen donors in the hydrogenation process, which can promote the conversion of macromolecules such as asphaltene. The catalytic oil slurry is introduced into the ebullated bed system, which can effectively improve the stability of the hydrogenated residue oil system and effectively slow down the coking of the reaction system.

[0060] 5、The present application has strong coupling, the ebullated bed hydrogenation unit, the first fixed bed hydrogenation unit and the second fixed bed hydrogenation unit are connected at high pressure and high temperature, the high gas phase components of the previous reaction are directly introduced into the subsequent device process, and the circulating hydrogen purification and concentration devices such as circulating hydrogen desulfurization tower are shared by each hydrogenation device, which greatly reduces the device investment and energy consumption. BRIEF DESCRIPTION OF DRAWINGS

[0061] Figure 1 It is a combined process flow diagram for heavy oil processing.

[0062] Wherein, 1-heavy oil raw material; 2-ebullated bed hydrogenation unit; 3-ebullated bed hydrogenation unit reaction effluent; 4-first high temperature and high pressure separation unit; 5-first gas phase stream; 6-first fixed bed hydrogenation reaction unit; 7-first liquid phase stream; 8-second fixed bed hydrogenation reaction unit first reaction zone; 9-second fixed bed hydrogenation reaction unit second reaction zone; 10-second fixed bed hydrogenation reaction unit third reaction zone; 11-second fixed bed hydrogenation reaction unit fourth reaction zone; 12-second high temperature and high pressure separation unit; 13-second gas phase stream; 14-hydrogen compressor; 15-second liquid phase stream; 16-first fractionation unit; 17-light hydrocarbon; 18-naphtha; 19-diesel product; 20-third high pressure and high temperature separation unit; 21-third gas phase stream; 22-third liquid phase stream; 23-second fractionation unit; 24-hydrogenated residue oil; 25-hydrogenated diesel oil; 26-hydrogenated naphtha; 27-hydrogenated light hydrocarbon; 28-catalytic cracking unit; 29-third fractionation unit; 30-catalytic liquefied gas; 31-catalytic naphtha; 32-catalytic diesel oil; 33-catalytic cycle oil; 34-catalytic oil slurry; 35-circulating hydrogen; 36-new hydrogen.

[0063] Figure 2 It is a combined process flow diagram for heavy oil processing used in Comparative Example 1.

[0064] Among them, 1-heavy oil feedstock; 2-fluidized bed hydrotreating unit; 3-first reaction zone of fixed bed reaction unit; 4-second reaction zone of fixed bed reaction unit; 5-third reaction zone of fixed bed reaction unit; 6-fourth reaction zone of fixed bed reaction unit; 4-7-high temperature and high pressure separation unit; 8-gas phase feed stream; 9-liquid phase feed stream; 10-first fractionation unit; 11-hydrogenated naphtha; 12-hydrogenated diesel; 13-hydrogenated residue oil; 14-catalytic cracking unit; 15-second fractionation unit; 16-liquefied petroleum gas; 17-catalytic gasoline; 18-catalytic diesel; 19-catalytic cycle oil; 20-catalytic slurry; 21-hydrogen compressor; 22-cycle hydrogen; 23-new hydrogen. Implementation

[0065] The technical features of the present invention will be further described in the following steps with reference to the accompanying drawings and embodiments, but these embodiments are not intended to limit the present invention.

[0066] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0067] In this document, for ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” “above,” “up,” etc., are used to describe the relationship of one element or feature to another element or feature in the accompanying drawings. It should be understood that spatial relative terms are intended to encompass different orientations of an object in use or operation, in addition to those depicted in the figures. For example, if an object in the figure is flipped, an element described as “below” or “under” another element or feature would be oriented “above” that element or feature. Thus, the exemplary term “below” can encompass both the downward and upward orientations. An object may also have other orientations (rotated 90 degrees or other orientations), and the spatial relative terms used herein should be interpreted accordingly.

[0068] In this document, the terms "first," "second," etc., are used to distinguish two different elements or parts, and are not used to define specific positions or relative relationships. In other words, in some embodiments, the terms "first," "second," etc., can also be used interchangeably.

[0069] In this document, all numeric values ​​of parameters (e.g., quantity or condition) should be understood to be modified by the term “about” in all cases, regardless of whether “about” actually appears before the numeric value.

[0070] like Figure 1As shown, this invention provides a combined heavy oil hydrotreating process. Heavy oil feedstock 1 first enters a fluidized bed hydrotreating unit 2, where it is mixed with recycled hydrogen 35 and fresh hydrogen 36 for reaction. The resulting fluidized bed hydrotreating unit effluent 3 enters a first high-temperature, high-pressure separation unit 4, where it is separated to obtain a first gaseous stream 5 and a first liquid stream 7. The first gaseous stream 5 enters a first fixed bed hydrotreating unit 6, and the reaction effluent enters a second high-temperature, high-pressure separation unit 12, where it is separated to obtain a second gaseous stream 13 and a second liquid stream 15. The second liquid stream 15 enters a first fractionation unit 16, where it is separated to obtain light hydrocarbons 17, naphtha 18, and diesel product 19. The second gaseous stream 13 enters a recycled hydrogen unit and is returned to each hydrotreating unit via a recycled hydrogen compressor 14. The first liquid stream 7 is mixed with recycled hydrogen 33 and fresh hydrogen 34 and sequentially enters the first reaction zone 8 and the second fixed bed hydrotreating unit. The reaction effluent from the second reaction zone 9, the third reaction zone 10, and the fourth reaction zone 11 enters the third high-temperature and high-pressure separation unit 20, where it is separated into a third gas-liquid feed stream 21 and a third liquid feed stream 22. The third gas feed stream 21 enters the circulating hydrogen unit and is returned to each hydrogenation reaction unit via the circulating hydrogen compressor 14. The third liquid feed stream 22 enters the second fractionation unit 23 and is separated into hydrogenated residue oil 24, hydrogenated diesel oil 25, hydrogenated naphtha 26, and hydrogenated light hydrocarbons 27. Hydrogenated diesel oil 25 is recycled to the first fixed-bed hydrogenation reaction unit 6. Hydrogenated residue oil 24 enters the catalytic cracking unit 28, where the generated oil enters the third fractionation unit 29 to obtain catalytic liquefied gas 30, catalytic naphtha 31, catalytic diesel oil 32, catalytic circulating oil 33, and catalytic slurry oil 34. Catalytic diesel oil 32 is returned to the first fixed-bed hydrogenation reaction unit 6, while catalytic circulating oil 33 and catalytic slurry oil 34 are returned to the fluidized bed hydrogenation unit 2.

[0071] like Figure 2 As shown, heavy oil feedstock 1 first enters the fluidized bed hydrotreating unit 2, where it reacts with recycled hydrogen 22 and fresh hydrogen 23. The resulting fluidized bed hydrotreating effluent is then mixed with recycled hydrogen 22 and enters the first reaction zone 3, second reaction zone 4, third reaction zone 5, and fourth reaction zone 6 of the fixed bed reaction unit. The effluent then enters the high-temperature, high-pressure separation unit 7, where it is separated into a gaseous stream 8 and a liquid stream 9. The recycled hydrogen from the purified gaseous stream 8 enters the recycled compressor 21, and the resulting recycled hydrogen 22 is returned to the hydrotreating system. The liquid stream 9 enters the first fractionation unit 10 to obtain hydrotreated naphtha 11, hydrotreated diesel 12, and hydrotreated residue 13. The hydrotreated residue 13 enters the catalytic cracking unit 14, and the resulting oil enters the second fractionation unit to obtain liquefied petroleum gas 16, catalytic gasoline 17, catalytic diesel 18, catalytic cycle oil 19, and catalytic slurry 20. The catalytic cycle oil 19 is returned to the catalytic cracking unit 14.

[0072] In this paper, the fluidized bed reactor used is the STRONG fluidized bed reactor with a built-in three-phase separator developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd.

[0073] In this paper, the properties of the heavy oil used in the examples and comparative examples are shown in Table 1.

[0074] Table 1

[0075]

[0076] Example 1

[0077] Example 1 uses Figure 1 The process flow shown is as follows.

[0078] Hydrogenated diesel from the second fractionation unit and catalytic diesel from the third fractionation unit are all returned to the first fixed-bed hydrogenation reaction unit, while catalytic circulating oil and catalytic slurry are all returned to the fluidized bed reaction unit.

[0079] The catalyst packed in the fluidized bed hydrogenation reaction unit is the FEM-10 fluidized bed hydrogenation catalyst developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd.; the reaction pressure in the fluidized bed reaction zone is 17 MPa, the hydrogen-to-oil volume ratio is 400, and the fluidized bed volume space velocity is 1.4 h⁻¹. -1 The fluidized bed reaction temperature is 395℃.

[0080] The first fixed-bed hydrogenation reaction unit is a single reactor with a double-bed configuration. The upper part is filled with FF-66 hydrorefining catalyst developed by Sinopec (Dalian) Oil Chemical Research Institute Co., Ltd., and the lower part is filled with FC-76 hydrocracking catalyst developed by Sinopec (Dalian) Oil Chemical Research Institute Co., Ltd.

[0081] The first fixed-bed hydrogenation reactor unit operates at a reaction temperature of 380℃, a hydrogen-to-oil volume ratio of 1200, a reaction pressure of 16 MPa, and a total space velocity (TVV) of 2.5 h⁻¹. -1 .

[0082] The second fixed-bed hydrogenation reaction unit is equipped with four reactors in series, with each reactor having a single bed. The catalysts for the first to fourth reactors are respectively FZC-12B, FZC-28A, FZC-33BT, and FZC-41BT developed by Sinopec (Dalian) Oil Chemical Research Institute Co., Ltd., according to the feed flow direction.

[0083] The second fixed-bed hydrogenation reactor had an average reaction temperature of 390℃, a hydrogen-to-oil volume ratio of 800, and a total volume hourly space velocity (TVHSV) of 0.25 h⁻¹. -1 The reaction pressure is 16 MPa.

[0084] The catalytic cracking unit uses DFC-1 catalytic cracking catalyst produced by Sinopec Catalyst Company Changling Branch. The riser outlet temperature is 525℃, the reaction pressure is 0.2MPa, the catalyst-to-oil ratio is 8.7, and the reaction time is 2.5s.

[0085] The cut-off point for naphtha and diesel products in the first fractionation unit is 200°C.

[0086] In the second fractionation unit, the cut-off point for hydrotreated naphtha and hydrotreated diesel is 200°C, and the cut-off point for hydrotreated diesel and hydrotreated residue is 350°C.

[0087] In the third fractionation unit, the cut-off point for catalytic naphtha and catalytic diesel is 200℃, for catalytic diesel and catalytic cycle oil it is 350℃, and for catalytic cycle oil and catalytic slurry it is 400℃.

[0088] Example 2

[0089] use Figure 1 The process flow shown is different from Example 1 in that some process parameters have changed.

[0090] The catalyst packed in the fluidized bed reaction zone is the FEM-10 fluidized bed hydrogenation catalyst developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd.; the reaction pressure in the fluidized bed reaction zone is 16 MPa, the hydrogen-to-oil volume ratio is 300, and the fluidized bed volume space velocity is 1.0 h⁻¹. -1 The fluidized bed reaction temperature is 400℃.

[0091] The first fixed-bed hydrogenation reaction unit is a single reactor with a double-bed configuration. The upper part is filled with FF-66 hydrorefining catalyst developed by Sinopec (Dalian) Oil Chemical Research Institute Co., Ltd., and the lower part is filled with FC-76 hydrocracking catalyst developed by Sinopec (Dalian) Oil Chemical Research Institute Co., Ltd.

[0092] The first fixed-bed hydrogenation reactor unit operates at a reaction temperature of 390℃, a hydrogen-to-oil volume ratio of 1000, a reaction pressure of 15 MPa, and a total space velocity (TVV) of 2.0 h⁻¹. -1 .

[0093] The second fixed-bed hydrogenation reaction unit is equipped with four reactors in series, with each reactor having a single bed. The catalysts for the first to fourth reactors are respectively FZC-12B, FZC-28A, FZC-33BT, and FZC-41BT developed by Sinopec (Dalian) Oil Chemical Research Institute Co., Ltd., according to the feed flow direction.

[0094] The second fixed-bed hydrogenation reactor had an average reaction temperature of 395℃, a hydrogen-to-oil volume ratio of 800, and a total volume hourly space velocity (TVHSV) of 0.22 h⁻¹. -1 The reaction pressure is 15 MPa.

[0095] The catalytic cracking unit uses DFC-1 catalytic cracking catalyst produced by Sinopec Catalyst Company Changling Branch. The riser outlet temperature is 525℃, the reaction pressure is 0.2MPa, the catalyst-to-oil ratio is 8.7, and the reaction time is 2.5s.

[0096] The cut-off point for naphtha and diesel products in the first fractionation unit is 200°C.

[0097] In the second fractionation unit, the cut-off point for hydrotreated naphtha and hydrotreated diesel is 200°C, and the cut-off point for hydrotreated diesel and hydrotreated residue is 350°C.

[0098] In the third fractionation unit, the cut-off point for catalytic naphtha and catalytic diesel is 200℃, for catalytic diesel and catalytic cycle oil it is 350℃, and for catalytic cycle oil and catalytic slurry it is 400℃.

[0099] Example 3

[0100] use Figure 1 The process flow shown is different from Example 1 in that all diesel products from the first fractionation unit are returned to the first fixed-bed reaction zone. Other process conditions are the same as in Example 1.

[0101] Example 4

[0102] use Figure 1 The process flow shown is different from Example 1 in that the hydrotreated diesel from the second fractionation unit and the catalytic diesel from the third fractionation unit are not returned to the first fixed-bed hydrotreating unit. Other process parameters are the same as in Example 1.

[0103] Example 5

[0104] use Figure 1 The process flow shown is different from Example 1 in that the catalytic circulating oil is not returned to the fluidized bed reaction unit.

[0105] Example 6

[0106] use Figure 1 The process flow shown is different from Example 1 in that the cutting point between catalytic diesel and catalytic cycle oil is 330°C; the catalytic cycle oil is divided into first catalytic cycle oil and second catalytic cycle oil, the first catalytic cycle oil is circulated to the fluidized bed hydrogenation unit, and the second catalytic cycle oil is self-circulated in the catalytic cracking unit; the mass ratio of the first catalytic cycle oil to the second catalytic cycle oil is 1:1.

[0107] Example 7

[0108] use Figure 1The process flow shown is different from Example 1 in that the cutting point between catalytic diesel and catalytic cycle oil is 330°C; the catalytic cycle oil is divided into first catalytic cycle oil and second catalytic cycle oil, the first catalytic cycle oil is circulated to the fluidized bed hydrogenation unit, and the second catalytic cycle oil is self-circulated in the catalytic cracking unit; the mass ratio of the first catalytic cycle oil to the second catalytic cycle oil is 3:1.

[0109] Comparative Example 1

[0110] Comparative Example 1 Figure 2 The process flow shown is as follows.

[0111] The catalyst packed in the fluidized bed reaction zone is the FEM-10 fluidized bed hydrogenation catalyst developed by Sinopec (Dalian) Petrochemical Research Institute Co., Ltd.; the reaction pressure in the fluidized bed reaction zone is 17 MPa, the hydrogen-to-oil volume ratio is 400, and the fluidized bed volume space velocity is 1.4 h⁻¹. -1 The fluidized bed reaction temperature is 395℃.

[0112] The fixed-bed hydrogenation reaction unit is set up with four reactors in series, with each reactor having a single bed. The catalysts from the first reactor to the fourth reactor are respectively loaded with FZC-12B, FZC-28A, FZC-33BT and FZC-41BT catalysts developed by Sinopec (Dalian) Oil Chemical Research Institute Co., Ltd., according to the feed flow direction.

[0113] The fixed-bed hydrogenation reactor had an average reaction temperature of 390℃, a hydrogen-to-oil volume ratio of 800, and a total space velocity of 0.25 h⁻¹. -1 The reaction pressure is 16 MPa.

[0114] The catalytic cracking unit uses DFC-1 catalytic cracking catalyst produced by Sinopec Catalyst Company Changling Branch. The riser outlet temperature is 525℃, the reaction pressure is 0.2MPa, the catalyst-to-oil ratio is 8.7, and the reaction time is 2.5s.

[0115] In the first fractionation unit, the cut-off point for hydrotreated naphtha and hydrotreated diesel is 200°C, and the cut-off point for hydrotreated diesel and hydrotreated heavy oil is 350°C.

[0116] In the second fractionation unit, the cutoff point for catalytic gasoline and catalytic diesel is 200°C, and the cutoff point for catalytic diesel and catalytic slurry is 370°C.

[0117] Table 2. Data from Examples and Comparative Cases

[0118]

[0119] *The pressure differential stabilization time of a fluidized bed reactor is the time it takes for the pressure drop in the fluidized bed reactor bed to rise to 1.3 times the initial bed pressure differential.

Claims

1. A combined process for heavy oil processing characterized by: The combined process comprises the following steps: (1) The heavy oil is fed into a ebullated-bed hydrogenation unit in the presence of hydrogen, and the reaction effluent is separated to obtain a first gas phase stream and a first liquid phase stream; (2) The first gas phase stream obtained in step (1) is mixed with hydrogen and fed into a first fixed-bed hydrogenation reaction unit, and the reaction effluent is separated to obtain a second gas phase stream and a second liquid phase stream, and the second liquid phase stream is fractionated to obtain light hydrocarbon, naphtha and diesel products; (3) The first liquid phase stream obtained in step (1) is mixed with hydrogen and fed into a second fixed-bed hydrogenation reaction unit, and the reaction effluent is separated to obtain a third gas phase stream and a third liquid phase stream, and the third liquid phase stream is fractionated to obtain light hydrocarbon, hydrogenated naphtha, hydrogenated diesel and hydrogenated residual oil; (4) The hydrogenated residual oil obtained in step (3) is fed into a catalytic cracking unit, and the reaction effluent is separated to obtain catalytic liquefied gas, catalytic naphtha, catalytic diesel, catalytic cycle oil and catalytic slurry oil; In step (1), the heavy oil raw material is at least one of atmospheric residual oil, vacuum residual oil and heavy asphalt; In step (1), the first gas phase stream and the first liquid phase stream are cut at a temperature of 280-350℃; In step (2), the first fixed-bed hydrogenation reaction unit comprises a hydrofining reaction zone and a hydrocracking reaction zone; the hydrofining reaction zone is provided with 1-3 hydrofining catalyst bed layers along the liquid phase flow direction, and the reaction is carried out with the hydrofining catalyst in the bed layer; the hydrofining reaction effluent enters the hydrocracking reaction zone, and the hydrocracking reaction zone is provided with 1-3 hydrocracking catalyst bed layers along the liquid phase flow direction, and the reaction is carried out with the hydrocracking catalyst in the bed layer; In step (4), the catalytic cycle oil is partially or entirely recycled to the ebullated-bed hydrogenation unit; In step (4), the catalytic slurry oil is treated by desolidification, and then is entirely or partially recycled to the ebullated-bed hydrogenation unit; The hydrogenated diesel obtained in step (3) and / or the catalytic diesel obtained in step (4) is recycled to the first fixed-bed hydrogenation reaction unit for treatment.

2. The combined process according to claim 1, characterized in that: In step (1), the ebullated-bed hydrogenation unit is provided with at least one ebullated-bed reactor.

3. The combined process according to claim 2, characterized in that: In step (1), the ebullated-bed hydrogenation unit is provided with one ebullated-bed reactor.

4. The combined process of claim 1, wherein: In step (1), the ebullated-bed reactor in the ebullated-bed hydrogenation unit is filled with an ebullated-bed hydrogenation catalyst, which comprises a carrier and an active metal component, and the active metal component is one or more of nickel, cobalt, molybdenum and tungsten; the carrier is one or more of alumina, silica and titania.

5. The combined process of claim 1, wherein: The operating conditions of the fluidized bed hydrogenation unit in step (1) are as follows: reaction temperature 350-450℃, reaction pressure 10.0-19.0 MPa, hydrogen / oil volume ratio 300-1000, liquid hourly space velocity 0.1-3.0 h -1 .

6. The combined process according to claim 5, characterized in that: The operating conditions of the fluidized bed hydrogenation unit in step (1) are as follows: reaction temperature 360-410°C, reaction pressure 13.0-18.0 MPa, hydrogen / oil volume ratio 400-600, liquid hourly space velocity 0.3-1.0 h -1 .

7. The combined process of claim 1, wherein: In step (2), the first fixed-bed hydrogenation reaction unit is provided with at least one fixed-bed hydrogenation reactor.

8. The combined process according to claim 7, characterized in that: In step (2), the first fixed-bed hydrogenation reaction unit is provided with a single fixed-bed hydrogenation reactor.

9. The combined process of claim 1, wherein: In step (2), the naphtha dry point is controlled to be not higher than 200℃; and the diesel is used as a clean fuel and is discharged from the unit.

10. The combined process of claim 1, wherein: The operating conditions of the first fixed-bed hydrogenation reaction unit in step (2) are as follows: average reaction temperature 340-390°C, reaction pressure 10.0-18.0 MPa, inlet hydrogen / oil volume ratio 800-2000, volume space velocity 0.8-2.0 h -1 .

11. The combined process according to claim 10, characterized in that: The operating conditions of the first fixed-bed hydrogenation reaction unit in step (2) are as follows: average reaction temperature 350-380°C, reaction pressure 13.0-17.0 MPa, inlet hydrogen / oil volume ratio 800-1500, volume space velocity 1.0-1.5 h -1 .

12. The combined process of claim 1, wherein: In step (3), the second fixed-bed hydrogenation reaction unit is provided with at least two fixed-bed hydrogenation reactors, and each fixed-bed hydrogenation reactor is provided with 1-2 catalyst bed layers.

13. The combined process according to claim 12, characterized in that: The second fixed bed hydrogenation reaction unit in step (3) is provided with 3-6 fixed bed hydrogenation reactors, and each fixed bed hydrogenation reactor is provided with one catalyst bed.

14. The combined process according to claim 13, characterized in that: The second fixed bed hydrogenation reaction unit in step (3) is provided with 4-5 fixed bed hydrogenation reactors in series.

15. The combined process of claim 1, wherein: The second fixed bed hydrogenation reaction unit in step (3) is sequentially filled with hydrogenation protection catalyst, metal removal catalyst, desulfurization catalyst and residual carbon removal catalyst according to the liquid phase flow direction; the hydrogenation protection catalyst, metal removal catalyst, desulfurization catalyst and residual carbon removal catalyst comprise a carrier and an active metal, wherein the active metal is one or more of nickel, cobalt, molybdenum and tungsten; the carrier is one or more of alumina, silica and titanium oxide.

16. The combined process of claim 1, wherein: The cutting point of the hydrogenated naphtha and the hydrogenated diesel oil in step (3) is 160-210℃.

17. The combined process according to claim 16, characterized in that: The cutting point of the hydrogenated naphtha and the hydrogenated diesel oil in step (3) is 180-200℃.

18. The combined process of claim 1, wherein: The operating conditions of the second fixed-bed hydrogenation reaction unit in step (3) are as follows: average reaction temperature 340-430°C, hydrogen / oil volume ratio at inlet 600-2000, volume space velocity 0.1-1.5 h -1 .

19. The combined process according to claim 18, characterized in that: The operating conditions of the second fixed bed hydrogenation reaction unit in step (3) are as follows: average reaction temperature 350-410°C, hydrogen / oil volume ratio at inlet 800-1500, volume space velocity 0.2-0.8 h -1 .

20. The combined process of claim 1 wherein: The catalytic cracking unit in step (4) is provided with at least one set of catalytic cracking device; the catalytic cracking device comprises a riser reactor, a settler, a regenerator and a cyclone separator.

21. The combined process of claim 20, wherein: The operating conditions of the riser reactor are as follows: the reaction temperature is 500-780℃; the mass ratio of water vapor to feed is 0.05:1-1:1; the reaction pressure is 0.10-1.0 MPa; and the contact time with the catalyst is 0.1-15.0 seconds.

22. The combined process of claim 21, wherein: The operating conditions of the riser reactor are as follows: the reaction temperature is 550-700℃; the mass ratio of water vapor to feed is 0.10:1-0.5:1; the reaction pressure is 0.10-0.5 MPa; and the contact time with the catalyst is 0.5-5.0 seconds.

23. The combined process of claim 1 wherein: The catalytic cracking unit in step (4) adopts a double riser process.

24. The combined process of claim 23, wherein: The naphtha obtained in step (2) is used as the feed of the second riser.

25. The combined process of claim 1 wherein: The cutting point of the catalytic naphtha and the catalytic diesel oil in step (4) is 160-220℃; the cutting point of the catalytic diesel oil and the catalytic cycle oil is 310-370℃; and the cutting point of the catalytic cycle oil and the catalytic oil slurry is 360-420℃.

26. The combined process of claim 25, wherein: The cutting point of the catalytic naphtha and the catalytic diesel oil in step (4) is 180-210℃; the cutting point of the catalytic diesel oil and the catalytic cycle oil is 330-350℃; and the cutting point of the catalytic cycle oil and the catalytic oil slurry is 370-400℃.

27. The combined process of claim 1 wherein: In step (4), the catalytic cycle oil is partially circulated to the ebullated bed hydrogenation unit; the catalytic cycle oil is divided into first catalytic cycle oil and second catalytic cycle oil, the first catalytic cycle oil is circulated to the ebullated bed hydrogenation unit, and the second catalytic cycle oil is self-circulated in the catalytic cracking unit; the mass ratio of the first catalytic cycle oil to the second catalytic cycle oil is 1:5-5:

1.

28. The combined process of claim 27, wherein: In step (4), the mass ratio of the first catalytic cycle oil to the second catalytic cycle oil is 1:1-3:

1.

29. The combined process of claim 1 wherein: In step (2), the second gas phase stream and / or the third gas phase stream in step (3) is treated by cold high separation, circulating hydrogen desulfurization and membrane separation; the hydrogen concentration in the hydrogen-rich gas obtained after the membrane separation treatment is above 95%, and the hydrogen-rich gas is pressurized by a compressor and then recycled.

30. The combined process of claim 1 wherein: The separation is performed by hot high separation; and the hot high separation equipment adopts a vertical structure.

31. The combined process of claim 30, wherein: The thermal high separation device is additionally provided with a thermal hydrogen stripping pipeline.

32. A heavy oil processing combined system for carrying out the combined process of claim 1, characterized by: The system comprises a ebullated bed hydrogenation unit, a first high-temperature high-pressure separation unit, a first fixed bed hydrogenation reaction unit, a second high-temperature high-pressure separation unit, a first fractionation unit, a second fixed bed hydrogenation reaction unit, a third high-temperature high-pressure separation unit, a second fractionation unit, a catalytic cracking unit and a third fractionation unit. The ebullated bed hydrogenation unit is used for receiving a heavy oil raw material, and reacting with hydrogen. The first high-temperature high-pressure separation unit is used for receiving and separating reaction effluent from the ebullated bed hydrogenation unit, and obtaining a first gas phase stream and a first liquid phase stream after separation. The first fixed bed hydrogenation reaction unit is used for receiving the first gas phase stream from the first high-temperature high-pressure separation unit, and reacting with hydrogen. The second high-temperature high-pressure separation unit is used for receiving and separating reaction effluent from the first fixed bed hydrogenation reaction unit, and obtaining a second gas phase stream and a second liquid phase stream after separation. The first fractionation unit is used for receiving and separating the second liquid phase stream from the second high-temperature high-pressure separation unit, and obtaining light hydrocarbon, naphtha and diesel products after fractionation. The second fixed bed hydrogenation reaction unit is used for receiving the first liquid phase stream from the first high-temperature high-pressure separation unit, and reacting with hydrogen. The third high-temperature high-pressure separation unit is used for receiving reaction effluent from the second fixed bed hydrogenation reaction unit, and obtaining a third gas phase stream and a third liquid phase stream after separation. The second fractionation unit is used for receiving the third liquid phase stream from the third high-temperature high-pressure separation unit, and obtaining light hydrocarbon, hydrogenated naphtha, hydrogenated diesel and hydrogenated residual oil after fractionation. The catalytic cracking unit is used for receiving hydrogenated residual oil from the second fractionation unit, and reacting with a catalytic cracking catalyst. The third fractionation unit is used for receiving reaction effluent from the catalytic cracking unit, and obtaining catalytic liquefied gas, catalytic naphtha, catalytic diesel, catalytic cycle oil and catalytic oil slurry after separation. The catalytic cycle oil obtained by the third fractionation unit partially or entirely enters the ebullated bed hydrogenation unit through a pipeline. The hydrogenated diesel from the second fractionation unit and / or the catalytic diesel from the third fractionation unit is communicated with the first fixed bed hydrogenation reaction unit through a pipeline.

33. The system of claim 32, wherein: The heavy oil processing combined system further comprises a recycle hydrogen unit, which is used for receiving the second gas phase stream from the second high-temperature high-pressure separation unit and / or the third gas phase stream from the third high-temperature high-pressure separation unit, and recycling as recycle hydrogen to each reaction unit after treatment.

34. The system of claim 32, wherein: The ebullated bed hydrogenation unit is provided with at least one ebullated bed reactor.

35. The system of claim 34, wherein: The ebullated bed hydrogenation unit is provided with one ebullated bed reactor.

36. The system of claim 32, wherein: The first fixed bed hydrogenation reaction unit is provided with at least one fixed bed hydrogenation reactor.

37. The system of claim 36, wherein: The first fixed bed hydrogenation reaction unit is provided with one fixed bed hydrogenation reactor.

38. The system of claim 32, wherein: The second fixed bed hydrogenation reaction unit is provided with at least one fixed bed hydrogenation reactor, and the fixed bed hydrogenation reactor is provided with 1-2 catalyst beds.

39. The system of claim 38, wherein: The second fixed bed hydrogenation reaction unit is provided with 3-5 fixed bed hydrogenation reactors, and the fixed bed hydrogenation reactor is provided with one catalyst bed.

40. The system of claim 38, wherein: The second fixed bed hydrogenation reaction unit is provided with 4-5 fixed bed hydrogenation reactors in series.

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