A method and system for treating heavy oil

Abstract

The present invention relates to a method and system for processing heavy oil, the method comprising: feeding raw oil, catalyst and hydrogen supply agent into a slurry bed reactor for hydrogenation treatment to obtain a hydrogenation treatment product; subjecting the hydrogenation treatment product to a first separation to obtain light oil and heavy oil; feeding the light oil, hydrogen and part of the heavy oil into a hydrocracking unit for a hydrocracking reaction to obtain a hydrocracking reaction product; subjecting the hydrocracking reaction product to a second separation to obtain crude hydrogen and a mixed product oil; subjecting the mixed product oil to stripping and a third separation to obtain a light oil product and a diesel product. The method of the present invention can reduce the energy consumption of the device, reduce the amount of hydrogen supply agent used, and allow the hydrogen supply agent to be recycled; each process of the method is carried out under relatively safe conditions, which can improve the safety of the device and enable the device to operate stably for a long period of time.

Description

Technical Field

[0001] The present application relates to the field of petrochemical engineering, and in particular, to a method and system for processing heavy oil. Background Art

[0002] Today, as the whole society calls for sustainable development and green environmental protection, oil refining companies are facing the competitive pressure of rising crude oil prices, deteriorating crude oil properties, rising demand for light oil products, and stricter fuel and environmental standards. At present, there are four types of residue oil hydrogenation processes in the world, namely fixed bed, fluidized bed, moving bed and slurry bed residue oil hydrogenation. The advantage of slurry bed hydrogenation technology is that it can process the worst residue oil, even coal, but its reaction system pressure is high, chemical hydrogen consumption is higher than that of fixed bed, fluidized bed and moving bed, and equipment investment is high; fixed bed hydrogenation process technology is mature, the device is mature, but the properties of the processed raw materials cannot be too bad; fluidized bed hydrogenation technology and moving bed technology are not yet mature, the device investment is high, and the process is complex. Pretreatment of heavy raw materials is of vital importance to energy saving and consumption reduction and long-term operation of the entire device.

[0003] CN112708462A and CN103102986A disclose a combined process for treating heavy oil, which is characterized by combining fixed-bed hydrogenation with coking, reducing the hydrogen consumption of the hydrogenation system and increasing the yield of high-quality low-sulfur petroleum coke;

[0004] CN107641525B discloses a suspended bed hydrogenation combined process and system, which is characterized in that a two-stage suspended bed reactor is used for hydrocracking and stabilization, thereby improving hydrogenation efficiency, delaying catalyst deactivation time, and reducing catalyst consumption;

[0005] In the existing technology, the combined process for processing heavy oil is increasingly valued. The combined process can reduce hydrogen consumption, save costs and optimize product quality. However, the existing high-pressure hydrogen reaction system has high investment, high energy consumption and great safety risks. Summary of the invention

[0006] The object of the present invention is to provide a relatively low-pressure raw material pretreatment combined hydrogenation process to solve the problems of high investment, high energy consumption and greater safety risks in high-pressure hydrogenation reaction systems.

[0007] In order to achieve the above-mentioned object, the first aspect of the present invention provides a method for treating heavy oil, which comprises: subjecting the feedstock oil, a first catalyst and a hydrogen donor to hydrogenation treatment in a slurry bed reactor to obtain a hydrogenation treatment product; subjecting the hydrogenation treatment product to a first separation to obtain a gas phase light component, a hydrogen donor after hydrogenation, light oil, heavy oil and a first unconverted oil containing a first catalyst; returning the first unconverted oil to the slurry bed reactor for further reaction; sending hydrogen, the light oil, a second catalyst and a part of the heavy oil to a hydrocracking unit for hydrocracking reaction to obtain a hydrocracking reaction product; subjecting the hydrocracking reaction product to a second separation to obtain crude hydrogen and a mixed product oil; subjecting the mixed product oil to stripping and a third separation to obtain a light oil product, a product diesel, a circulating diesel and a second unconverted oil; sending the hydrogen donor after hydrogenation to a hydrogen donor hydrogenation unit for hydrogenation regeneration to obtain a regenerated hydrogen donor and unreacted hydrogen; and returning the regenerated hydrogen donor to the slurry bed reactor for recycling.

[0008] Optionally, the method further comprises: returning the second unconverted oil to the hydrocracking unit for further reaction;

[0009] Optionally, the method further comprises: returning the circulating diesel as a supplementary hydrogen supply agent to the slurry bed reactor to continue the reaction.

[0010] Optionally, the method further comprises: performing gas desulfurization treatment on the gas product obtained by the second separation to obtain the crude hydrogen; sending the crude hydrogen to a membrane separation device for separation to obtain membrane-separated hydrogen; and returning the membrane-separated hydrogen and the unreacted hydrogen to the hydrocracking unit after compression to continue the reaction;

[0011] Optionally, the method further comprises: sending a portion of the new hydrogen into the hydrogen donor hydrogenation unit, and sending another portion of the new hydrogen into the hydrocracking unit after being compressed.

[0012] Optionally, the reaction conditions of the hydrotreatment include: reaction temperature of 150-450°C, reaction pressure of 5-70 bar, reaction time of 0.5-10 h, and a weight ratio of the feedstock oil to the hydrogen donor of 1.25-100, preferably 2-5; the reaction conditions of the hydrocracking include: reaction temperature of 350-430°C, reaction pressure of 100-180 bar, reaction time of 0.5-2.5 h, and hydrogen-to-oil volume ratio of 500-1200; the hydrogen donor is selected from one or more of cyclohexane, methylcyclohexane, decahydronaphthalene and cyclohexadiene; the first catalyst is an oil-soluble organic homogeneous molybdenum-based and / or supported nickel-molybdenum-based ultrafine powder; the second catalyst is a supported nickel-molybdenum-based catalyst.

[0013] Optionally, the first separation is carried out in a distillation tower, and the distillation cut point between the hydrogen supply agent after hydrogen supply and the light oil is 130-160°C, and the distillation cut point between the light oil and the heavy oil is 300-360°C; the distillation cut point between the heavy oil and the first unconverted oil is 480-540°C; the second separation is carried out in a cold / hot high-pressure separator and / or a cold / hot low-pressure separator; the third separation is carried out in a distillation tower, and the distillation range between the product diesel and the circulating diesel is the same; the distillation cut point between the circulating diesel and the second unconverted oil is 340-360°C.

[0014] Optionally, the feedstock oil is selected from one or more of vacuum residue oil, deasphalted oil, atmospheric residue oil, crude oil fractions with an initial boiling point of more than 350° C., and extra-thick crude oil.

[0015] The second aspect of the present invention provides a system for processing heavy oil, which includes a hydroprocessing unit, a hydrocracking unit, a stripping separation unit and a hydrogenation unit; the hydroprocessing unit includes a slurry bed reactor and a first separation device; the slurry bed reactor includes a feedstock oil inlet, a hydrogenation agent inlet, an oil-soluble catalyst inlet and a hydroprocessing product outlet; the first separation device includes a hydroprocessing product inlet, a hydrogenation agent outlet after hydrogenation, a light oil outlet, a heavy oil outlet and a first unconverted oil outlet; the hydrocracking unit includes a hydrocracking reactor and a second separation device; the hydrocracking reactor includes a hydrogen inlet, A light oil inlet, a heavy oil inlet and a hydrocracking reaction product outlet; the second separation device includes a hydrocracking reaction product inlet, a second separated gas product outlet and a mixed product oil outlet; the stripping separation unit includes a connected stripping device and a third separation device, the stripping device includes a product oil inlet to be stripped, a gas inlet and a stripping product oil outlet, the third separation device includes a stripping product oil inlet, a light oil product outlet, a product diesel outlet, a circulating diesel outlet and a second unconverted oil outlet; the hydrogen supply agent hydrogenation unit includes a hydrogen supply agent inlet after hydrogen supply, a hydrogen inlet, an unreacted hydrogen outlet and a regenerated hydrogen supply agent outlet;

[0016] The hydrotreated product outlet of the slurry bed reactor is connected to the hydrotreated product inlet of the first separation device; the first unconverted oil outlet of the first separation device is connected to the feed oil inlet of the slurry bed reactor; the light oil outlet and the heavy oil outlet of the first separation device are respectively connected to the light oil inlet and the heavy oil inlet of the hydrocracking reactor; the hydrocracking reaction product outlet of the hydrocracking reactor is connected to the hydrocracking reaction product inlet of the second separation device; the mixed product oil outlet of the second separation device is connected to the product oil to be stripped inlet of the stripping device; the stripping product oil outlet of the stripping device is connected to the stripping product oil inlet of the third separation device; the hydrogen supply agent outlet after hydrogen supply of the first separation device is connected to the hydrogen supply agent inlet after hydrogen supply of the hydrogen supply agent hydrogenation unit, and the regenerated hydrogen supply agent outlet of the hydrogen supply agent hydrogenation unit is connected to the hydrogen supply agent inlet of the slurry bed reactor.

[0017] Optionally, the second unconverted oil outlet of the third separation device is connected to the heavy oil inlet of the hydrocracking unit; and the circulating diesel outlet of the third separation device is connected to the feed oil inlet of the slurry bed reactor.

[0018] Optionally, the system also includes a hydrogen purification unit, which includes a desulfurization device, a membrane separation device and a circulating hydrogen compressor that are connected in sequence; the desulfurization device includes a second separation gas product inlet and a crude hydrogen outlet; the membrane separation device includes a crude hydrogen inlet and a membrane separation hydrogen outlet; the circulating hydrogen compressor includes a membrane separation hydrogen inlet and a compressed circulating hydrogen outlet; the second separation gas product outlet of the second separation device is connected to the second separation gas product inlet of the desulfurization device; the crude hydrogen outlet of the desulfurization device and the unreacted hydrogen outlet of the hydrogen supply agent hydrogenation unit are respectively connected to the crude hydrogen inlet of the membrane separation device; the membrane separation hydrogen outlet of the membrane separation device is connected to the membrane separation hydrogen inlet of the circulating hydrogen compressor; the compressed circulating hydrogen outlet of the circulating hydrogen compressor is connected to the hydrogen inlet of the hydrocracking unit.

[0019] Optionally, the system also includes a new hydrogen inlet and a new hydrogen compressor; the new hydrogen inlet is connected to the inlet of the new hydrogen compressor and the hydrogen inlet of the hydrogen supply agent hydrogenation unit respectively; the outlet of the new hydrogen compressor is connected to the gas-liquid mixture inlet of the hydrocracking reactor.

[0020] Through the above technical scheme, after the feedstock oil and the hydrogen supply agent are hydrogenated under the catalysis of the first catalyst, the obtained light oil and part of the heavy oil are mixed with hydrogen, and a hydrocracking reaction is carried out under the action of the second catalyst to obtain product oil and gas. The hydrogen supply agent used can be recycled through hydrogenation; the method of the present invention can reduce the energy consumption of the device, reduce the amount of hydrogen supply agent, and make the hydrogen supply agent recyclable; each process of the method is carried out under relatively safe conditions, which can improve the safety of the device and enable the device to operate stably for a long period of time.

[0021] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0023] Figure 1 The present invention is a process flow chart of an embodiment of a system for processing heavy oil.

[0024] Description of Reference Numerals

[0025] A, slurry bed reactor; B, first separation device; C, hydrogenation unit for hydrogen donor; D, hydrocracking reactor; E, second separation device; F, stripping separation unit; G, membrane separation device; H, new hydrogen compressor; J, circulating hydrogen compressor;

[0026] 1. Crude oil; 2. Hydrogen donor; 3. First catalyst; 4. Hydrogenation product; 5. Light component in gas phase; 6. Hydrogen donor after hydrogenation; 7. Light oil; 8. Heavy oil; 9. Heavy oil product; 10. First unconverted oil; 11. Hydrocracking reaction product; 12. Crude hydrogen; 13. Mixed product oil; 14. Light oil product; 15. Circulating diesel; 16. Membrane separation hydrogen; 17. Compressed circulating hydrogen; 18. New hydrogen; 19. Compressed new hydrogen; 20. Regenerated hydrogen; 21. Unreacted hydrogen; 22. Regenerated hydrogen donor; 23. Second unconverted oil; 24. Product diesel. DETAILED DESCRIPTION

[0027] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0028] In the present disclosure, unless otherwise stated, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in normal use. In addition, the terms "first, second, third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first, second, third" may explicitly or implicitly include one or more of the features. In the description of the present disclosure, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0029] The first aspect of the present invention provides a method for treating heavy oil, which comprises: subjecting a raw oil, a first catalyst and a hydrogen donor to hydrogenation treatment in a slurry bed reactor to obtain a hydrogenation treatment product; subjecting the hydrogenation treatment product to a first separation to obtain a gas phase light component, a hydrogen donor after hydrogenation, light oil, heavy oil and a first unconverted oil containing a first catalyst; returning the first unconverted oil to the slurry bed reactor for further reaction; sending hydrogen, the light oil, a second catalyst and a portion of the heavy oil to a hydrocracking unit for hydrocracking reaction to obtain a hydrocracking reaction product; subjecting the hydrocracking reaction product to a second separation to obtain crude hydrogen and a mixed product oil; subjecting the mixed product oil to stripping and a third separation to obtain a light oil product, a product diesel, a circulating diesel and a second unconverted oil; sending the hydrogen donor after hydrogenation to a hydrogen donor hydrogenation unit for hydrogenation regeneration to obtain a regenerated hydrogen donor and unreacted hydrogen; and returning the regenerated hydrogen donor to the slurry bed reactor for recycling.

[0030] Through the above technical scheme, after the raw oil and the hydrogen supply agent are hydrotreated under the catalysis of the first catalyst, the obtained light oil and part of the heavy oil are mixed with hydrogen, and a hydrocracking reaction is carried out under the action of the second catalyst to obtain product oil and gas; if the part of the heavy oil does not meet the hydrocracking feed, it can be partially used as the raw oil for hydrogenation. The hydrogen supply agent used can be recycled through hydrogenation; the method of the present invention can reduce the energy consumption of the device, reduce the amount of hydrogen supply agent used, and make the hydrogen supply agent recyclable; each process of the method is carried out under relatively safe conditions, which can improve the safety of the device and enable the device to operate stably for a long period of time.

[0031] In one embodiment, the flow ratio of the regenerated hydrogen donor returning to the slurry bed reactor to the fresh hydrogen donor is 0.1 to 99:1.

[0032] In one embodiment, the method further includes: returning the second unconverted oil to the hydrocracking unit for continued reaction; the unreacted materials in the second unconverted oil can be reacted again, thereby improving the utilization rate of the light oil and heavy oil and reducing costs.

[0033] Optionally, the method further comprises: returning the circulating diesel as a supplementary hydrogen supply agent to the slurry bed reactor to continue the reaction. In this embodiment, the above method can further reduce the use of hydrogen supply agents and reduce costs.

[0034] In one embodiment, the method further comprises: performing gas desulfurization treatment on the gas product obtained by the second separation to obtain the crude hydrogen; sending the crude hydrogen to a membrane separation device for separation to obtain membrane separated hydrogen; and returning the membrane separated hydrogen and the unreacted hydrogen to the hydrocracking unit after compression to continue the reaction;

[0035] Optionally, the method further comprises: sending a portion of the new hydrogen into the hydrogen donor hydrogenation unit, and sending another portion of the new hydrogen into the hydrocracking unit after being compressed.

[0036] In one embodiment, the reaction conditions of the hydrotreatment include: a reaction temperature of 150 to 450° C., preferably 420 to 430° C.; a reaction pressure of 5 to 70 bar, preferably 35 to 50 bar; a reaction time of 0.5 to 10 h, preferably 0.5 to 2.5 h; and a dosage ratio of the feedstock oil to the hydrogen donor of 1.25 to 100, preferably 2 to 5.

[0037] In the above embodiment, by hydrotreating the crude oil and reacting under suitable reaction conditions and material ratios, the reaction process can be completed, reducing the pressure of subsequent processes and equipment, thereby reducing energy consumption. In order to further complete the reaction, each condition is optimized.

[0038] In one embodiment, the reaction conditions of the hydrocracking include: a reaction temperature of 350-430° C., a reaction pressure of 100-180 bar, a reaction time of 0.5-2.5 h, and a hydrogen-to-oil volume ratio of 500-1200.

[0039] In the above embodiment, the "oil" in the hydrogen-oil refers to the sum of the light oil products and part of the heavy oil products entering the hydrocracking unit, and the hydrogen-oil volume ratio refers to the ratio of the volume of hydrogen to the total volume of the light oil products and part of the heavy oil products.

[0040] In one embodiment, the hydrogen donor is selected from one or more of cyclohexane, methylcyclohexane, decahydronaphthalene and cyclohexadiene; the first catalyst is an oil-soluble organic homogeneous molybdenum catalyst and / or a supported nickel-molybdenum ultrafine powder catalyst, preferably an oil-soluble organic homogeneous molybdenum catalyst.

[0041] In one embodiment, the second catalyst is a supported nickel-molybdenum catalyst.

[0042] In one embodiment, the distillation cut point between the hydrogen donor after hydrogen supply and the light oil is 130-160°C; the distillation cut point between the light oil and the heavy oil is 300-360°C; the distillation cut point between the heavy oil and the first unconverted oil is 480-540°C.

[0043] In one embodiment, the second separation is performed in a cold / hot high pressure separator and / or a cold / hot low pressure separator.

[0044] In one embodiment, the third separation is carried out in a distillation tower, the distillation range between the product diesel and the recycled diesel is the same; the distillation cut point between the recycled diesel and the second unconverted oil is 340-360°C.

[0045] In one embodiment, the feedstock oil is a heavy feedstock oil with high viscosity and many impurities. For example, the feedstock oil can be selected from one or more of vacuum residue oil, deasphalted oil, atmospheric residue oil, crude oil fractions with an initial distillation point of >350°C, and extra-heavy crude oil.

[0046] In one embodiment, if Figure 1 As shown, a method for treating heavy oil comprises:

[0047] The raw oil 1, hydrogen donor 2 and first catalyst 3 are mixed and sent to the slurry bed reactor A, and the hydroprocessed product 4 is directly sent to the first separation device B for separation to obtain gas phase light component 5, hydrogen donor 6 after hydrogenation, light oil 7, heavy oil 8, heavy oil product 9 and first unconverted oil containing catalyst 10. The first unconverted oil 10 is returned to the slurry bed reactor A to participate in the reaction; the hydrogen donor 6 after hydrogenation is sent to the hydrogen donor hydrogenation unit C to obtain the regenerated hydrogen donor 22, and returned to the slurry bed reactor A to participate in the reaction;

[0048] The light oil 7 and the heavy oil 8 are mixed with hydrogen and sent to the hydrocracking unit D for hydrocracking reaction. The obtained hydrocracking reaction product 11 enters the second separation device E, and obtains crude hydrogen 12 and mixed product oil 13; the mixed product oil 13 is passed through the stripping separation unit F to obtain the light oil product 14, the circulating diesel 15, the second unconverted oil 23 and the product diesel 24; wherein the circulating diesel 15 is returned to the slurry bed reactor A as a supplementary hydrogen supply agent, and the second unconverted oil 23 is returned to the hydrocracking unit D to continue to participate in the reaction;

[0049] The crude hydrogen 12 is purified by the membrane separation device G, mixed with the unreacted hydrogen 21 from the hydrogen supply hydrogenation unit C, and then compressed by the circulating hydrogen compressor J. Part of the new hydrogen is sent to the hydrogen supply hydrogenation unit C, and part is compressed by the new hydrogen compressor H and mixed with the compressed circulating hydrogen 17 and then sent to the hydrocracking unit D.

[0050] The second aspect of the present invention provides a system for processing heavy oil, which includes a hydroprocessing unit, a hydrocracking unit, a stripping separation unit and a hydrogenation unit for hydrogenating a hydrogenating agent; the hydroprocessing unit includes a slurry bed reactor and a first separation device; the slurry bed reactor includes a feedstock oil inlet, a hydrogenation agent inlet, an oil-soluble catalyst inlet and a hydroprocessing product outlet; the first separation device includes a hydroprocessing product inlet, a hydrogenation agent outlet after hydrogenation, a light oil outlet, a heavy oil outlet and a first unconverted oil outlet; the hydrocracking unit includes a hydrocracking reactor and a second separation device; the hydrocracking reactor includes a hydrogen inlet , a light oil inlet, a heavy oil inlet and a hydrocracking reaction product outlet; the second separation device includes a hydrocracking reaction product inlet, a second separated gas product outlet and a mixed product oil outlet; the stripping separation unit includes a connected stripping device and a third separation device, the stripping device includes a product oil inlet to be stripped, a gas outlet and a stripping product oil outlet, the third separation device includes a stripping product oil inlet, a light oil product outlet, a product diesel outlet, a circulating diesel outlet and a second unconverted oil outlet; the hydrogen supply agent hydrogenation unit includes a hydrogen supply agent inlet after hydrogen supply, a hydrogen inlet, an unreacted hydrogen outlet and a regenerated hydrogen supply agent outlet;

[0051] The hydrotreated product outlet of the slurry bed reactor is connected to the hydrotreated product inlet of the first separation device, so that the hydrotreated product after hydrotreatment enters the first separation device for first separation; the first unconverted oil outlet of the first separation device is connected to the feed oil inlet of the slurry bed reactor, so as to return the first unconverted oil separated in the first separation device to the slurry bed reactor for further reaction; the light oil outlet and the heavy oil outlet of the first separation device are respectively connected to the light oil inlet and the heavy oil inlet of the hydrocracking reactor, so that the light oil and part of the heavy oil are sent to the hydrocracking unit for hydrocracking reaction; the hydrocracking reaction product outlet of the hydrocracking reactor is connected to the hydrocracking reaction product inlet of the second separation device, so as to return the first unconverted oil separated in the first separation device to the slurry bed reactor for further reaction. The hydrocracking reaction product is sent to a second separation device for a second separation; the mixed product oil outlet of the second separation device is connected with the inlet of the product oil to be stripped of the stripping device, so that the product oil enters the stripping device for stripping; the stripping product oil outlet of the stripping device is connected with the stripping product oil inlet of the third separation device, so that the stripping product oil can enter the third separation device for separation; the hydrogen supply agent outlet after hydrogen supply of the first separation device is connected with the hydrogen supply agent inlet after hydrogen supply of the hydrogen supply agent hydrogenation unit, which is used to send the hydrogen supply agent after hydrogen supply into the hydrogen supply agent hydrogenation unit for hydrogenation regeneration; the regenerated hydrogen supply agent outlet of the hydrogen supply agent hydrogenation unit is connected with the hydrogen supply agent inlet of the slurry bed reactor, which is used to send the regenerated hydrogen supply agent into the slurry bed reactor for reaction.

[0052] Optionally, the first separation device is a distillation tower; the second separation device includes a cold / hot high-pressure separator and / or a cold / hot low-pressure separator, matching related tanks, one or more heat exchangers and one or more air coolers; the third separation device is a distillation tower.

[0053] In one embodiment, the second unconverted oil outlet of the third separation device is connected to the heavy oil inlet of the hydrocracking unit, so as to return the second unconverted oil to the hydrocracking unit for further reaction.

[0054] In one embodiment, the circulating diesel outlet of the third separation device is connected to the feedstock oil inlet of the slurry bed reactor, so that the circulating diesel can be returned to the slurry bed reactor as a supplementary hydrogen supply agent to continue the reaction, thereby enabling further cracking. At the same time, the circulating diesel can also be used as a hydrogen supply agent.

[0055] In one embodiment, the system further comprises a hydrogen purification unit, the hydrogen purification unit comprising a desulfurization device, a membrane separation device and a circulating hydrogen compressor which are connected in sequence; the desulfurization device comprises a second separated gas product inlet and a crude hydrogen outlet; the membrane separation device comprises a crude hydrogen inlet and a membrane separation hydrogen outlet; the circulating hydrogen compressor comprises a membrane separation hydrogen inlet and a compressed circulating hydrogen outlet; the second separated gas product outlet of the second separation device is connected to the second separated gas product inlet of the desulfurization device, so that the second separated gas product separated by the second separation device can enter the desulfurization device for desulfurization treatment; the crude hydrogen outlet of the desulfurization device is connected to the second separated gas product inlet of the desulfurization device, so that the second separated gas product separated by the second separation device can enter the desulfurization device for desulfurization treatment; The hydrogen outlet and the unreacted hydrogen outlet of the hydrogen supply agent regeneration unit are respectively connected to the crude hydrogen inlet of the membrane separation device, so that the crude hydrogen generated by the desulfurization device and the unreacted hydrogen generated in the hydrogen supply agent regeneration unit enter the membrane separation device for hydrogen purification; the membrane separation hydrogen outlet of the membrane separation device is connected to the membrane separation hydrogen inlet of the circulating hydrogen compressor, which is used to pass the membrane separation hydrogen generated by the membrane separation device into the circulating hydrogen compressor for compression; the compressed circulating hydrogen outlet of the circulating hydrogen compressor is connected to the hydrogen inlet of the hydrocracking unit, which is used to pass the compressed circulating hydrogen generated by the circulating hydrogen compressor into the hydrocracking unit for reaction.

[0056] In one embodiment, the system also includes a new hydrogen inlet and a new hydrogen compressor; the new hydrogen inlet is respectively connected to the inlet of the new hydrogen compressor and the hydrogen inlet of the hydrogen supply agent hydrogenation unit, so that a part of the new hydrogen can enter the hydrogen supply agent hydrogenation unit for regeneration reaction, and the other part can be compressed by the new hydrogen compressor; the outlet of the new hydrogen compressor is connected to the gas-liquid mixture inlet of the hydrocracking reactor, so as to send the compressed new hydrogen into the hydrocracking reactor for hydrocracking reaction.

[0057] In one embodiment, the system also includes a stripping device for stripping the product oil produced after the second separation; the stripping device includes a mixed product oil inlet and a stripping product oil outlet; the mixed product oil inlet of the stripping device is connected to the mixed product oil outlet of the second separation device, and is used to send the product oil into the stripping device for stripping treatment; the stripping product oil outlet of the stripping device is connected to the stripping product oil inlet of the third separation device, and is used to send the stripping product oil of the stripping device into the third separation device for third separation.

[0058] The present invention is further described in detail by way of examples. The raw materials used in the examples can be obtained through commercial sources.

[0059] Example 1

[0060] Use Figure 1 The system shown performs residual oil hydroprocessing, specifically comprising the following steps:

[0061] The hydrogen supply agent 2 (cyclohexane, the amount added at one time is 100t, and the flow rate after stabilization is 10t / h), the catalyst 3 (oil-soluble organic Mo-based catalyst, the amount added at one time is 15t, and the flow rate after stabilization is 1.5t / h) and 100t / h of crude oil 1 are pressurized, heat-exchanged, heated to 30bar, and then fed into a slurry bed reactor A at 420°C to obtain a hydroprocessing product 4; the mass ratio of the crude oil 1 to the hydrogen supply agent 2 is 1:1, and the agent-oil ratio is 1:50; the hydroprocessing product 4 is passed through a fractionating tower to obtain a gas phase light component 5, a hydrogen supply agent 6 after hydrogenation (distillation range 4 0~110℃), light oil 7 (distillation range 110~350℃), heavy oil 8 (distillation range 350~560℃) and the first unconverted oil 10 containing the catalyst; the first unconverted oil 10 is returned to the slurry bed reactor A; the hydrogen supply agent 6 after hydrogen supply is sent to the hydrogen supply agent hydrogenation unit C, and the regenerated hydrogen supply agent 22 is returned to the entrance of the slurry bed reactor A; the light oil 7 and part of the heavy oil 8 are mixed with hydrogen and then pressurized to 150bar, heated to 370℃ and then sent to the hydrocracking reactor D, at a reaction temperature of 370℃, a reaction pressure of 150bar, and a reactor volume space velocity of 0.7h -1, a hydrocracking reaction is carried out under the condition of a hydrogen-to-oil volume ratio of 700; a hydrocracking reaction product 11 is obtained; the hydrocracking reaction product 11 is separated and desulfurized to obtain circulating hydrogen and a mixed product oil 13; the mixed product oil 13 is stripped and distilled to obtain a light oil product 14 (distillation range 50-150°C), a circulating diesel 15 (distillation range 280-350°C), a product diesel 24 (distillation range 160-280°C) and a second unconverted oil 23 (distillation range>350°C), and the second unconverted oil 23 is sent to the inlet of the hydrocracking reactor D; the circulating hydrogen 12 is purified, compressed, mixed with new hydrogen and sent to the inlet of the cracking reactor D; a part of the new hydrogen 18 is sent to the hydrogenation unit C of the hydrogen supply agent, and the unreacted hydrogen 21 separated after hydrogenation separation is pressurized together with the membrane separation hydrogen 16 and sent to the inlet of the cracking reactor D, and the regenerated hydrogen supply agent 22 obtained is returned to the slurry bed reactor A to continue the reaction, and the flow rate of the stabilized regenerated hydrogen supply agent is 90t / h. The product indicators of the hydroprocessing product 4 obtained by this method are shown in Table 2.

[0062] Table 1 Raw oil properties

[0063]

[0064] Table 2 Product indicators

[0065]

[0066]

[0067] Comparative Example 1

[0068] Compared with the traditional slurry bed reaction: the crude oil, catalyst and hydrogen are pressurized and heated to 430°C and 16.8MPaG respectively and then sent into the slurry bed reactor for hydrogenation reaction. The obtained product indicators are shown in Table 3.

[0069] Table 3 Product indicators

[0070]

[0071]

[0072] It can be seen from the data in Tables 2 and 3, and from the comparison of the data in Example 1 and Comparative Example 1, when the crude oil is treated using the method described in the present invention, the reaction pressure is greatly reduced, and the viscosity, sulfur content and metal content of the crude oil are significantly reduced; after subsequent treatment of the liquid product, the output of the light oil product can be increased.

[0073] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0074] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0075] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for treating heavy oil, characterized in that: The method includes: The feedstock oil, the first catalyst and the hydrogen donor are subjected to hydrogenation treatment in a slurry bed reactor to obtain a hydrogenation product; The hydroprocessed product is subjected to a first separation to obtain a gas phase light component, a hydrogen supply agent after hydrogen supply, light oil, heavy oil and a first unconverted oil containing a first catalyst; and the first unconverted oil is returned to the slurry bed reactor for further reaction; Sending hydrogen, the light oil, the second catalyst and part of the heavy oil to a hydrocracking unit for hydrocracking reaction to obtain a hydrocracking reaction product; subjecting the hydrocracking reaction product to a second separation to obtain crude hydrogen and mixed product oil; The mixed product oil is subjected to steam stripping and third separation to obtain a light oil product, a product diesel, a circulating diesel and a second unconverted oil; The hydrogen supply agent after hydrogen supply is sent to the hydrogen supply agent hydrogenation unit for hydrogenation regeneration to obtain a regenerated hydrogen supply agent and unreacted hydrogen; the regenerated hydrogen supply agent is returned to the slurry bed reactor for recycling; The reaction conditions of the hydroprocessing include: a reaction temperature of 150-450° C., a reaction pressure of 5-70 bar, a reaction time of 0.5-10 h, and a weight ratio of the feedstock oil to the hydrogen donor of 1.25-100; The hydrogen donor is selected from one or more of cyclohexane, methylcyclohexane and cyclohexadiene.

2. The method according to claim 1, characterized in that The method further comprises: returning the second unconverted oil to the hydrocracking unit for further reaction; The method also includes: returning the circulating diesel as a supplementary hydrogen supply agent to the slurry bed reactor to continue the reaction.

3. The method according to claim 1, characterized in that The method also includes: performing gas desulfurization treatment on the gas product obtained by the second separation to obtain the crude hydrogen; sending the crude hydrogen to a membrane separation device for separation to obtain membrane-separated hydrogen; and returning the membrane-separated hydrogen and the unreacted hydrogen to the hydrocracking unit after compression to continue the reaction.

4. The method according to claim 3, characterized in that The method further comprises: sending a part of the new hydrogen into the hydrogen supply agent hydrogenation unit, and sending another part of the new hydrogen into the hydrocracking unit after being compressed.

5. The method according to claim 1, characterized in that The weight ratio of the feedstock oil to the hydrogen donor is 2 to 5; The reaction conditions of the hydrocracking include: reaction temperature of 350-430°C, reaction pressure of 100-180 bar, reaction time of 0.5-2.5 h, and hydrogen-to-oil volume ratio of 500-1200; The first catalyst is an oil-soluble organic homogeneous molybdenum-based and / or supported nickel-molybdenum-based ultrafine powder; the second catalyst is a supported nickel-molybdenum-based catalyst.

6. The method according to claim 1, characterized in that The first separation is carried out in a fractionation tower, the fraction cut point between the hydrogen supply agent and the light oil after hydrogen supply is 130-160°C, the fraction cut point between the light oil and the heavy oil is 300-360°C; the fraction cut point between the heavy oil and the first unconverted oil is 480-540°C; The second separation is performed in a cold / hot high pressure separator and / or a cold / hot low pressure separator; The third separation is carried out in a distillation tower, and the distillation range between the product diesel and the circulating diesel is the same; the distillation cut point between the circulating diesel and the second unconverted oil is 340-360°C.

7. The method according to claim 1, characterized in that The raw oil is selected from one or more of vacuum residue oil, deasphalted oil, atmospheric residue oil, crude oil fractions with an initial boiling point greater than 350° C., and extra-thick crude oil.

8. A system for treating heavy oil using the method according to any one of claims 1 to 7, characterized in that: The system includes a hydroprocessing unit, a hydrocracking unit, a stripping separation unit and a hydrogen supply agent hydrogenation unit; The hydroprocessing unit comprises a slurry bed reactor and a first separation device; the slurry bed reactor comprises a feedstock oil inlet, a hydrogen supply agent inlet, an oil-soluble catalyst inlet and a hydroprocessing product outlet; the first separation device comprises a hydroprocessing product inlet, a hydrogen supply agent outlet after hydrogen supply, a light oil outlet, a heavy oil outlet and a first unconverted oil outlet; The hydrocracking unit comprises a hydrocracking reactor and a second separation device; the hydrocracking reactor comprises a hydrogen inlet, a light oil inlet, a heavy oil inlet and a hydrocracking reaction product outlet; the second separation device comprises a hydrocracking reaction product inlet, a second separated gas product outlet and a mixed product oil outlet; The stripping separation unit comprises a connected stripping device and a third separation device, wherein the stripping device comprises an inlet for a product oil to be stripped, a gas outlet and an outlet for a stripping product oil, and the third separation device comprises an inlet for a stripping product oil, an outlet for a light oil product, an outlet for a product diesel, an outlet for a circulating diesel and a second unconverted oil outlet; The hydrogen supply agent hydrogenation unit comprises a hydrogen supply agent inlet after hydrogen supply, a hydrogen inlet, an unreacted hydrogen outlet and a regenerated hydrogen supply agent outlet; The hydrotreated product outlet of the slurry bed reactor is connected to the hydrotreated product inlet of the first separation device; the first unconverted oil outlet of the first separation device is connected to the feed oil inlet of the slurry bed reactor; the light oil outlet and the heavy oil outlet of the first separation device are respectively connected to the light oil inlet and the heavy oil inlet of the hydrocracking reactor; the hydrocracking reaction product outlet of the hydrocracking reactor is connected to the hydrocracking reaction product inlet of the second separation device; the mixed product oil outlet of the second separation device is connected to the product oil to be stripped inlet of the stripping device; the stripping product oil outlet of the stripping device is connected to the stripping product oil inlet of the third separation device; the hydrogen supply agent outlet after hydrogen supply of the first separation device is connected to the hydrogen supply agent inlet after hydrogen supply of the hydrogen supply agent hydrogenation unit, and the regenerated hydrogen supply agent outlet of the hydrogen supply agent hydrogenation unit is connected to the hydrogen supply agent inlet of the slurry bed reactor.

9. The system according to claim 8, characterized in that The second unconverted oil outlet of the third separation device is connected to the heavy oil inlet of the hydrocracking unit; The circulating diesel outlet of the third separation device is communicated with the feedstock oil inlet of the slurry bed reactor.

10. The system according to claim 8, characterized in that The system also includes a hydrogen purification unit, which includes a desulfurization device, a membrane separation device and a circulating hydrogen compressor connected in sequence; The desulfurization device comprises a second separated gas product inlet and a crude hydrogen outlet; The membrane separation device comprises a crude hydrogen inlet and a membrane separation hydrogen outlet; The circulating hydrogen compressor comprises a membrane separation hydrogen inlet and a compressed circulating hydrogen outlet; The second separated gas product outlet of the second separation device is connected to the second separated gas product inlet of the desulfurization device; the crude hydrogen outlet of the desulfurization device and the unreacted hydrogen outlet of the hydrogen supply agent hydrogenation unit are respectively connected to the crude hydrogen inlet of the membrane separation device; the membrane separation hydrogen outlet of the membrane separation device is connected to the membrane separation hydrogen inlet of the circulating hydrogen compressor; the compressed circulating hydrogen outlet of the circulating hydrogen compressor is connected to the hydrogen inlet of the hydrocracking unit.

11. The system according to claim 10, characterized in that The system also includes a new hydrogen inlet and a new hydrogen compressor; the new hydrogen inlet is connected to the inlet of the new hydrogen compressor and the hydrogen inlet of the hydrogen supply agent hydrogenation unit respectively; the outlet of the new hydrogen compressor is connected to the hydrogen inlet of the hydrocracking reactor.

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