A slurry bed reactor, a poor quality oil slurry bed hydrocracking system and method

Abstract

This invention discloses a slurry bed reactor, a slurry bed hydrocracking system for low-grade oil, and a method thereof. The slurry bed reactor includes a shell, a reactor outlet, a reactor inlet, and an internal empty tank. The reactor outlet is located at the top of the shell; the reactor inlet is located at the bottom of the shell; the internal empty tank is located inside the shell, and spiral fins are provided between the internal empty tank and the shell. The slurry bed reactor of this invention features an empty tank with spiral channels inside, allowing the material inside the reactor to flow in a spiral upward manner, enhancing mass transfer and optimizing the material flow pattern within the slurry bed reactor. Using the slurry bed hydrocracking system and method for low-grade oil of this invention can control coking in the slurry bed hydrocracking reaction of low-grade heavy oil, and ensure the safe and stable operation of the low-grade heavy oil slurry bed hydrocracking unit, effectively extending the unit's operating cycle.

Description

Technical Field

[0001] This invention belongs to the field of oil refining, specifically to the field of deep processing of inferior and heavy oil in the process of lightening heavy oil, and relates to heavy oil slurry bed hydrocracking equipment and process, particularly to a slurry bed reactor, inferior oil slurry bed hydrocracking system and method. Background Technology

[0002] For low-quality oil, processes such as heavy oil catalytic cracking (feedstock requirements: residual carbon value less than 8%, total metal content not exceeding 20 μg / g) and heavy oil fixed-bed hydrocracking (feedstock requirements: residual carbon value less than 15%, total metal content not exceeding 200 μg / g) are employed. However, the catalyst surface deactivates rapidly due to coking and metal deposition. Delayed coking processes yield high coke production, but the coke quality is poor (high sulfur and ash content). Furthermore, pellet coke may be generated within the coking tower, affecting the safe operation of the coking unit. While fluidized bed hydrocracking technology can process low-quality heavy oil, its process flow and equipment are complex, resulting in a low yield of light oil. Compared to the above technologies, heavy oil slurry-bed hydrocracking technology can process even lower-quality feedstocks, with superior product quality and light oil yield, making it the most suitable technology currently available.

[0003] Currently, the mainstream heavy oil slurry bed hydrocracking processes include the following: the EST process of ENI in Italy, the HDHPLUS-SHP process jointly developed by PDVSA in Venezuela and Axens in France, the VRSH process of Chevron, the VCC process of KBR and BP, and the Uniflex process of UOP. Each of these processes has its own advantages and characteristics, but there are significant differences in terms of operating conditions, catalyst types, and technical solutions.

[0004] The EST process uses an oil-soluble residue slurry bed hydrocracking catalyst, which is converted into a nano-scale thin-layer form of carrier-free MoS2 in a slurry bed reactor. It employs complex in-reactor process control technology. Its main characteristics are: ① multiple recycling of unconverted oil, high total feedstock conversion rate, and no fuel oil or coke products; ② superior product quality, with gasoline and diesel meeting Euro IV standards; ③ near-complete removal of metals from the feedstock; ④ lower consumption of the relatively expensive catalyst.

[0005] The HDHPLUS-SHP process involves two slurry bed reactors with complex internal components operating in series. It uses a solid particulate catalyst and requires the addition of a certain amount of additives. The catalyst system has insufficient dispersibility in the feedstock and adopts relatively harsh reaction process conditions. It also requires the removal of about 10% of unconverted tail oil, resulting in insufficient economic efficiency of the unit.

[0006] The VCC process employs a non-metallic slurry-bed hydrocracking catalyst and multiple reactors operating in series to reduce the impact of reactant backmixing. The operating pressure is 18–20 MPa; increasing the reaction severity can achieve a single-pass conversion rate of 95% for the residue oil. In the thermal separator, light components are separated from the unconverted tail oil. The unconverted tail oil is completely discharged from the bottom of the thermal separator without recirculation. This external discharge of tail oil aims to control coking and maintain stable operation of the unit, but its economic efficiency is relatively poor.

[0007] Chinese patent CN201510190769.9 discloses a two-stage heavy oil slurry bed hydrocracking equipment and method. The method contains a two-stage slurry bed hydrocracking system. Each stage is equipped with a reactor containing a riser and a downcomer and a separator. The reactor is also designed with equipment such as a distributor, a demister, and an expansion section to enhance the flow of reactants.

[0008] The defects of this technology or the shortcomings of this invention are as follows: the reactor of the above method contains many internal components and has a complex structure. If coke accumulates in the reactor, it will be difficult to clean. At the same time, the complex structure of the reactor also makes it difficult to operate the device stably. The method uses powdered catalyst, which is difficult to disperse effectively in poor quality heavy oil. Furthermore, this invention does not provide any explanation regarding product quality, post-processing of reaction products, and stable operation of the device.

[0009] Chinese patent CN201410367441.5 discloses a two-stage hydrocracking refining method for inferior oil. This method employs a process flow of "two-stage slurry bed reactors connected in series with two fixed-bed reactors." Inferior heavy oil feedstock undergoes hydrocracking in the first-stage slurry bed reactor. After separation of light and heavy components by a high-temperature separator, the heavy components enter the second-stage slurry bed reactor for further hydrocracking. The reaction products are then separated into light and heavy components again by a high-temperature separator. The heavy components are then subjected to vacuum distillation to remove solid impurities. The vacuum distillate and the light components from the two-stage slurry bed reactors are then refined in the fixed-bed reactor to obtain high-quality light distillate oil.

[0010] The drawbacks of this technology, or its shortcomings compared to the present invention, are as follows: With prolonged operation, solid particulate impurities from the reaction coke and catalyst tend to accumulate and clog the high-temperature separator and vacuum distillation tower. Furthermore, the limited ability of these two devices to separate solid impurities will clog subsequent process pipelines and equipment. In particular, if the clogging occurs in the bed of the fixed-bed reactor, it will lead to an increase in the pressure drop of the fixed-bed reactor, affecting the entire operating cycle of the unit. In addition, this method uses waste iron-based desulfurizing agents as the main agent, with added bituminous coal, sulfur, or organic sulfides in a slurry bed catalyst system. This type of catalyst has poor dispersion in the feedstock oil, and its activity in inhibiting reaction coke formation and hydrogenation is insufficient.

[0011] Chinese patent CN201410276723.4 discloses a method and apparatus for slurry bed hydrocracking of residual oil. This method employs a "slurry bed + fixed bed" process flow, where inferior heavy oil feedstock is processed in a slurry bed reactor, then separated into light and heavy components by a fractionation device before entering a fixed bed reactor for hydrorefining or hydrocracking to obtain high-quality light distillate oil.

[0012] The deficiencies of this technology, or its shortcomings relative to the present invention, are as follows: The above method does not employ a dedicated hydrogen mixing device, relying instead on pipeline hydrogen injection, resulting in poor mixing performance. The slurry-bed catalyst used is a solid particulate material produced by spray granulation of a mixture of iron powder and ammonium molybdate, which exhibits poor dispersion in inferior raw materials, limiting its activity. The mixture of reactive coke, asphaltene, heavy metals, and catalyst is discharged at the bottom of a high-temperature, high-pressure separator. This high-temperature, high-pressure separator solids removal process poses significant risks and safety hazards and requires proprietary technology, which is not explicitly described in this method. Furthermore, the method lacks a dedicated solids removal device. As the system operates for an extended period, residual catalyst solid particles and reactive coke impurities will clog the bed of the fixed-bed reactor, leading to increased reactor pressure drop and affecting the stable operation of the unit.

[0013] Chinese patent CN201210241249.2 discloses a highly efficient hydrotreating process for inferior heavy oil and residue oil. This process uses a slurry bed reactor connected in series with multiple fixed bed reactors of different functions. First, the inferior heavy oil and residue oil feedstock is pretreated in the slurry bed reactor. Then, the liquid phase material obtained by gas-liquid separation enters a series of fixed bed reactors for deep refining treatment such as demetallization, desulfurization, and denitrification, thereby obtaining high-quality hydrotreated oil.

[0014] The shortcomings of this technology, or its deficiencies compared to the present invention, are as follows: The above method lacks a deep hydrocracking unit for low-quality oil, resulting in insufficient conversion depth of the residue oil and a low yield of light distillate oil. Furthermore, it lacks online analysis equipment, making it impossible to monitor the cracking reaction and the condensation of heavy components into coke in a timely manner. Additionally, it lacks equipment for removing solid particles such as reacted coke. As the unit operates, these solid particles will clog the fixed-bed reactor bed, leading to increased reactor pressure drop and affecting the unit's operating cycle.

[0015] Therefore, it is necessary to provide a hydrocracking equipment or process that can improve the conversion rate of residual oil and inhibit the deposition of reactive coke. Summary of the Invention

[0016] The purpose of this invention is to provide a slurry bed reactor, a slurry bed hydrocracking system and method for low-quality oil. The slurry bed reactor has an internal empty tank with a spiral channel, allowing the material inside to flow in a spiral upward motion, enhancing mass transfer and optimizing the material flow pattern within the reactor. Using the low-quality oil slurry bed hydrocracking system and method of this invention, the coking rate of the low-quality heavy oil slurry bed hydrocracking reaction can be controlled to <1% (i.e., the mass content of toluene-insoluble matter in the slurry bed hydrocracking product oil is <1%). The produced gasoline and diesel fractions meet the requirements of the China VI standard for vehicle fuel oil, and the wax oil fraction meets the quality requirements for feed or blending feed to the hydrocracking unit. All fractions above 500℃ are converted, with no tailings generated, and the low-quality heavy oil slurry bed hydrocracking unit maintains safe and stable operation, effectively extending the unit's operating cycle (continuous stable operation for more than 3 years, annual operating time for more than 8400 hours).

[0017] To achieve the above objectives, the present invention provides a slurry bed reactor, which includes a shell, a reactor outlet, a reactor inlet, and an internal empty tank. The reactor outlet is located at the top of the shell; the reactor inlet is located at the bottom of the shell; the internal empty tank is located inside the shell, and spiral fins are provided between the internal empty tank and the shell.

[0018] Preferably, the internal empty barrel and the shell are connected in a spiral form by spiral fins to form an integral internal component.

[0019] Preferably, flanges are provided at both ends of the housing, and the internal components can be disassembled when the flanges are opened.

[0020] The outer wall of the built-in empty tank of the slurry bed reactor of the present invention is connected to the inner wall of the slurry bed reactor cylinder in a spiral form by spiral fins to form an integral internal component. When the reactor is shut down for maintenance, the flanges at both ends of the slurry bed reactor can be opened to remove the entire internal component, which is convenient for cleaning reaction coke and other impurities on the slurry bed reactor and internal components.

[0021] Preferably, the number of spiral fins is multiple, and the spacing between every two spiral fins is 1 to 10% of the height of the slurry bed reactor, preferably 1 to 5%; the thickness of the spiral fins is 1 to 5 mm, preferably 1 to 3 mm; the width of the spiral fins (the distance between the internal empty tank and the inner wall of the slurry bed reactor) is 5 to 15% of the diameter of the slurry bed reactor, preferably 5 to 10%.

[0022] Preferably, the reactants are fed into the reactor inlet and flow spirally upwards into the slurry bed reactor along the material flow channels formed by the spiral fins for reaction; the reaction temperature is 380–400°C, the reaction pressure is 14.0–18.0 MPa, and the volume hourly space velocity is 1.0–3.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 500–1000.

[0023] Preferably, the interior of the built-in empty tank is equipped with multiple electrically heated salt bath modules to provide auxiliary heating for the slurry bed reactor, which can increase the internal temperature of the slurry bed reactor by 50-150°C.

[0024] Preferably, the outer wall of the built-in empty tank is equipped with multiple symmetrically distributed temperature gauges for monitoring the temperature inside the slurry bed reactor, and preferably two temperature gauges.

[0025] The present invention also provides a slurry bed hydrocracking system for inferior oil, which includes: a first hydrogen mixer, a slurry bed reactor, an online analysis device, a high-pressure separator, a slurry reaction vessel, a fixed bed refining reactor, and a fractionation device. The first hydrogen mixer is used to mix low-quality oil feedstock containing catalyst with hydrogen. The first hydrogen mixer is connected to the bottom of a slurry bed reactor, where the mixed low-quality oil feedstock containing catalyst and hydrogen undergo preliminary hydrocracking. An online analysis device is connected to the top of the first hydrogen mixer and the slurry bed reactor, used to analyze the properties of the products from the slurry bed reactor and determine their compliance. A high-pressure separator is connected to the online analysis device to separate the qualified products into liquid and gaseous phases. A slurry reactor is connected to the high-pressure separator to perform deep hydrocracking of the liquid phase products. A fixed-bed refining reactor is connected to the slurry reactor to refine the products from the slurry reactor. A fractionation unit is connected to the first hydrogen mixer and the fixed-bed refining reactor to separate the products from the fixed-bed refining reactor, obtaining high-quality gasoline, diesel, and wax oil products, as well as hydrocracking tailings. The hydrocracking tailings are returned to the first hydrogen mixer, mixed with fresh feedstock, and then subjected to preliminary hydrocracking again in the slurry bed reactor.

[0026] Preferably, it also includes a heating furnace, which is located between the first hydrogen mixer and the slurry bed reactor, for heating the mixed low-quality oil feedstock containing the catalyst with hydrogen.

[0027] Preferably, it also includes a second hydrogen mixer, which is located between the high-pressure separator and the slurry reactor, and is used to mix the liquid phase product with hydrogen.

[0028] Preferably, the reactor further includes a filter assembly, a gas-liquid separator, and a third hydrogen mixer, which are sequentially arranged between the slurry reactor and the fixed-bed refining reactor. The filter assembly is used to remove large particulate impurities larger than 50 μm from the reaction coke. The gas-liquid separator is used to separate the product after impurity removal into gas and liquid phases to obtain gaseous and liquid phase materials. The third hydrogen mixer is used to mix the liquid phase material with hydrogen.

[0029] Preferably, there are multiple slurry reactors, preferably 4-6. The number of slurry reactors meets the requirements for continuous operation of processing the pretreatment reaction products of the slurry bed reactor for processing inferior oil and providing raw materials for the fixed bed refining reactor. The operating conditions are: reaction temperature 400-430℃, reaction pressure 18.0-22.0MPa, reaction time 0.5-2h, and stirring rate 10-60r / min.

[0030] Preferably, the height-to-diameter ratio of the slurry reactor is 2 to 15:1, and more preferably 5 to 10:1. The slurry reactor is equipped with a stirring device inside and a hydrogen injection port at the top for adjusting the reaction pressure and discharging all reaction products after the reaction is completed.

[0031] Preferably, there are multiple fixed-bed refining reactors, preferably two; each fixed-bed refining reactor contains two or more catalyst beds, preferably three catalyst beds, and its operating conditions are: reaction temperature 300–380℃, reaction pressure 5.0–10.0 MPa, and volumetric hourly space velocity 1.5–2.5 h⁻¹. -1 The hydrogen-to-oil volume ratio is 300–500:1.

[0032] Preferably, the fixed-bed refining reactor is switched out periodically for operation, and the fixed-bed refining reactor of the slurry-bed hydrocracking system that cuts out inferior oil is used for coke burning regeneration and activation operations.

[0033] Preferably, the online analysis device includes an online density meter, a rapid analyzer for toluene insolubles, and a signal transmission and control computer, which adjusts the reaction process parameters in a timely manner by controlling the density of the reaction products and the amount of coke produced.

[0034] Preferably, the fractionation unit includes a fractionation furnace, an atmospheric column, a vacuum column, and a fractionation tower. The fractionation furnace is connected to a fixed-bed refining reactor, and the fractionation tower is connected to a first hydrogen mixer. Preferably, one atmospheric column is connected in series with one vacuum column.

[0035] Preferably, the catalyst comprises a carrier oil, which is at least one of catalytic diesel oil, coking diesel oil, hydrocracking diesel oil, and coking wax oil rich in aromatic hydrocarbons and cycloalkanes.

[0036] Preferably, the inferior oil feedstock is at least one of the following: catalytic slurry oil, high sulfur and nitrogen residue oil, high metal residue oil, high residual carbon residue oil, atmospheric residue oil, vacuum residue oil, extra-heavy crude oil, heavy crude oil, and oil sands asphalt.

[0037] This invention also provides a method for hydrocracking of inferior oil in a slurry bed, which includes the following steps:

[0038] S1: The inferior oil feedstock containing the catalyst is heated by heat exchange, mixed with hydrogen in the first hydrogen mixer, heated by the heater, and then enters the slurry bed reactor for preliminary hydrocracking reaction.

[0039] S2: The reaction products from step S1 are tested by an online analysis device to determine if they are qualified. If qualified, they are separated in a high-pressure separator to obtain liquid and gaseous products. If unqualified, they are returned to the first hydrogen mixer, mixed with fresh feedstock, and then subjected to a preliminary hydrocracking reaction in a slurry bed reactor.

[0040] S3: The liquid product from step S2 and hydrogen enter the second hydrogen mixer. After mixing in the second hydrogen mixer, it enters the slurry reactor for deep hydrocracking of inferior oil.

[0041] S4: The reaction product from step S3 is filtered to remove large particulate impurities larger than 50μm of reaction coke. The liquid phase material obtained by the gas-liquid separator is mixed with circulating hydrogen in the third hydrogen mixer and then enters the fixed bed refining reactor for refining treatment to remove impurities such as sulfur, nitrogen, metals, and aromatics.

[0042] S5: The reaction products from step S4 are heated in a fractionation furnace and then separated in a fractionation unit to obtain high-quality gasoline, diesel and wax oil products and hydrotreated tailings fraction. The hydrotreated tailings fraction is returned to the first hydrogen mixer, mixed with fresh feedstock, and then undergoes preliminary hydrocracking reaction in a slurry bed reactor.

[0043] In this invention, the inferior oil feedstock, after heat exchange with a mixed catalyst, is mixed with hydrogen in a first hydrogen mixer and then heated to the reaction temperature in a heater before entering a slurry bed reactor for preliminary hydrocracking. The reaction products are analyzed online to determine the properties of the pre-reaction products. If the product properties are unqualified, the product is fully recycled back to the first hydrogen mixer for further hydrogen mixing and then enters the slurry bed reactor for further processing, with appropriate adjustments to the reaction process parameters. If the product properties are qualified, the product enters a high-pressure separator for gas-liquid separation. The high-resolution gaseous product is dehydrated by a hydrogen compressor and returned to the circulating hydrogen compressor via a buffer tank. The high-resolution liquid product is mixed with hydrogen supplied by a new hydrogen compressor in a second hydrogen mixer via a pressure reducing valve and then enters a slurry reactor for deep conversion of the inferior oil. After the reaction products enter the filter group to remove large particles of reactive coke, the liquid phase products obtained by gas-liquid separation in the gas-liquid separator are mixed with hydrogen again in the third hydrogen mixer and then enter the fixed bed refining reactor for refining reaction to remove impurities such as sulfur, nitrogen, metals, and slurry bed reactive coke. After being heated in the fractionation furnace, they enter the fractionation tower group for separation to obtain high-quality gasoline, diesel, wax oil and hydrotreated tailings. All hydrotreated tailings are recycled back to the first hydrogen mixer to be mixed with fresh feedstock and participate in the reaction again.

[0044] The present invention provides a first hydrogen mixer, a second hydrogen mixer, and a third hydrogen mixer in front of the slurry bed reactor, the slurry reaction vessel, and the fixed bed refining reactor, respectively, which can increase the dissolved hydrogen capacity of the inferior oil slurry bed hydrocracking system.

[0045] The present invention preferably uses a combination process of "slurry bed reactor + slurry reaction vessel + fixed bed refining reactor", which follows the idea of ​​stepwise cracking and stepwise removal of impurities, and finally achieves high conversion rate of residue oil and obtains fuel oil that meets the National VI standard and high-quality hydrocracking feedstock.

[0046] The present invention preferably employs a combination of filter arrays and fixed bed protective agent layers to remove impurities such as coke and solid particles contained in the reaction products in a stepwise manner.

[0047] The present invention has the following advantages:

[0048] 1. Improve residue-to-oil conversion rate and suppress excessive cracking of light components caused by reaction coke deposition and material backmixing. The slurry bed reactor of this invention features an internal empty tank with a spiral channel, allowing materials to flow in a spiral upward motion, enhancing mass transfer and optimizing material flow within the reactor. Under the same reaction conditions, the residue-to-oil conversion rate of this slurry bed reactor is 1.05-1.25 times that of a reactor without internal components; or, at the same residue-to-oil conversion rate, the reaction severity of this slurry bed reactor is significantly reduced (reaction temperature is 10-30°C lower than that of a reactor without internal components, and reaction pressure is 2-8 MPa lower). This effectively reduces the risk of gravity deposition of reaction coke and also suppresses the risk of excessive cracking of light components caused by material backmixing.

[0049] 2. Increase the hydrogen dissolution capacity of inferior raw materials. This invention incorporates multiple hydrogen mixers suitable for inferior heavy oil, improving hydrogen dispersion and mass transfer in inferior raw materials, achieving a hydrogen dissolution capacity 10 to 20 times that of direct hydrogen injection through ordinary pipelines or simple hydrogen mixing tanks.

[0050] 3. The product quality and techno-economic efficiency of the method of this invention are good. This invention adopts a novel slurry bed reactor, multiple hydrogen mixers, filter groups, and online analysis equipment. By setting up a two-stage reaction system of "slurry bed reactor + slurry reaction vessel" and a combination process of "slurry bed + fixed bed", the overall process flow is optimized to realize the design concept of stepwise cracking of inferior oil and stepwise deep refining of product oil. Compared with the existing technology process, which has "a total conversion rate of residue oil greater than 90% and requires the discharge of 1-10% tailings", the residue oil of this invention is 100% converted into light distillate oil with zero tailings generation. The gasoline and diesel fractions obtained by this invention meet the China VI vehicle fuel oil standard, and the wax oil fraction meets the feed requirements of the hydrocracking unit. The coking rate is <1%, the unit can operate continuously and stably for more than 3 years, and the annual operating time is more than 8400 hours.

[0051] 4. The inferior oil slurry bed hydrocracking system and method of the present invention optimizes the material flow pattern inside the slurry bed reactor, suppresses excessive cracking of light components caused by backmixing, and sets up multiple hydrogen mixers and online analysis devices. It adopts a combined process flow of "slurry bed reactor + slurry reaction vessel + fixed bed refining reactor" to achieve continuous and stable operation of the unit while ensuring a high conversion rate of inferior oil. The method of the present invention can directly produce high-quality automotive fuel oil and hydrocracking feedstock from inferior heavy oil, with no tailings discharge, realizing a highly efficient and deep conversion process of inferior heavy oil. Attached Figure Description

[0052] Figure 1 This is a schematic cross-sectional view of an embodiment of the slurry bed reactor of the present invention.

[0053] In the attached figures, the following labels are used:

[0054] 101. Reactor outlet; 102. Flange; 103. Spiral fins; 104. Internal cylindrical empty tank; 105. Reactor inlet.

[0055] Figure 2 This is a schematic diagram of the process flow of an embodiment of the inferior oil slurry bed hydrocracking system of the present invention.

[0056] In the attached figures, the following labels are used:

[0057] 1. Catalyst preparation tank; 2. Feedstock preparation tank; 3. Feedstock pump; 4. Heat exchanger; 5-1. First hydrogen mixer; 5-2. Second hydrogen mixer; 5-3. Third hydrogen mixer; 6. Heating furnace; 7. Slurry bed reactor; 8. Online analysis device; 9. High-pressure separator; 10. Pressure reducing valve; 11. Slurry reaction vessel; 12. Filter group; 13. Gas-liquid separator; 14. Fixed bed refining reactor; 15. Fractionating furnace; 16. Fractionating tower; 17. Hydrogen compressor and buffer tank; 18. Circulating hydrogen compressor; 19. Fresh hydrogen compressor.

[0058] Figure 3 This is a schematic diagram of a conventional residue oil slurry bed hydrocracking process in the prior art.

[0059] In the attached figures, the following labels are used:

[0060] 1. Catalyst preparation tank; 2. Feed oil preparation tank; 3. Feed pump; 4. Heat exchanger; 5. Inferior oil; 6. Slurry bed reactor; 7. High-pressure separator; 8. Pressure reducing valve; 9. Low-pressure separator; 10. Distillation furnace; 11. Distillation tower; 12. Circulating hydrogen compressor; 13. Low-pressure dehydration and buffer tank; 14. Compressor dehydration and buffer tank. Detailed Implementation

[0061] The present invention will be further described below with reference to the accompanying drawings.

[0062] Please refer to Figure 1 , Figure 1 This is a cross-sectional schematic diagram of an embodiment of the slurry bed reactor of the present invention. The slurry bed reactor of the present invention includes a shell, a reactor outlet 101, a reactor inlet 105, and an internal empty tank 104. The reactor outlet 101 is located at the top of the shell, the reactor inlet 105 is located at the bottom of the shell, the internal empty tank 104 is located inside the shell, and a spiral fin 103 is provided between the internal empty tank 104 and the shell.

[0063] The present invention does not particularly limit the number of spiral fins 103, which can be set to one or more; when the number of spiral fins 103 is set to multiple, the number can be, for example, 2-8, the spacing between each pair of spiral fins 103 is 1-10% of the height of the slurry bed reactor, preferably 1-5%; the thickness of the spiral fins 103 is 1-5 mm, preferably 1-3 mm; the width of the spiral fins 103 (the distance between the internal empty tank 104 and the inner wall of the slurry bed reactor) is 5-15% of the diameter of the slurry bed reactor, preferably 5-10%.

[0064] In the slurry bed reactor of the present invention, the reactants are fed into the reactor through the reactor inlet 105 and flow spirally upwards into the slurry bed reactor along the material flow channel formed by the spiral fins 103 for reaction; the reaction temperature is 380-400°C, the reaction pressure is 14.0-18.0 MPa, and the volume hourly space velocity is 1.0-3.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 500–1000.

[0065] The internal empty tank 104 and the shell are connected in a spiral form by spiral fins 103 to form an integral internal component. During operation of the slurry bed reactor, the raw material enters from the reactor inlet 105 at the bottom of the reactor, passes through the spiral channel formed by the spiral fins 103, and then exits from the reactor outlet 101 at the top. The slurry bed reactor of this invention has spiral fins 103 between the internal empty tank 104 and the shell. The spiral fins 103 are arranged to form a spiral channel within the slurry bed reactor. After entering the slurry bed reactor, the raw material flows from bottom to top in a spiral form, enhancing mass transfer and optimizing the material flow pattern within the slurry bed reactor.

[0066] Preferably, the interior of the built-in empty tank 104 is equipped with multiple electrically heated salt bath modules to provide auxiliary heating for the slurry bed reactor, which can increase the internal temperature of the slurry bed reactor by 50 to 150°C.

[0067] Preferably, the outer wall of the built-in empty tank 104 is provided with multiple symmetrically distributed temperature gauges for monitoring the temperature inside the slurry bed reactor. The number of temperature gauges in this invention includes, but is not limited to, 2-4, preferably 2 temperature gauges.

[0068] Preferably, flanges 102 are provided at both ends of the housing, and the internal components can be disassembled when the flanges 102 are opened.

[0069] The outer wall of the built-in empty tank 104 of the slurry bed reactor of the present invention is connected to the inner wall of the slurry bed reactor shell by spiral fins 103 in a spiral form to form an integral internal component. When the reactor is shut down for maintenance, the flanges 102 at both ends of the slurry bed reactor can be opened to remove the entire internal component, which is convenient for cleaning impurities such as reaction coke on the slurry bed reactor and internal components.

[0070] Please refer to Figure 2 , Figure 2 This is a schematic diagram of the process flow for an embodiment of the inferior oil slurry bed hydrocracking method of the present invention. The inferior oil slurry bed hydrocracking system of the present invention includes a catalyst preparation tank 1, a feedstock preparation tank 2, a first hydrogen mixer 5-1, a slurry bed reactor, an online analysis device, a high-pressure separator, a slurry reaction vessel, a fixed bed refining reactor, and a fractionation device.

[0071] Oil-soluble slurry-bed hydrocracking catalyst and carrier oil are mixed under stirring conditions in catalyst preparation tank 1. Inferior oil and catalyst oil containing carrier oil from catalyst preparation tank 1 are mixed under stirring conditions in feedstock preparation tank 2, and then pumped into heat exchanger 4 via feedstock pump 3. Heat exchanger 4 heats the reaction feedstock before it is fed into first hydrogen mixer 5-1. First hydrogen mixer 5-1 is used to mix the inferior oil feedstock containing catalyst with hydrogen. This invention does not particularly limit the types of carrier oil and inferior oil. The carrier oil can be at least one of the following: catalytic diesel oil rich in aromatics and cycloalkanes, coking diesel oil, hydrocracking diesel oil, and coking wax oil. The inferior oil feedstock can be at least one of the following: catalytic slurry oil, high-sulfur and high-nitrogen residue oil, high-metal residue oil, high-carbon residue oil, atmospheric residue oil, vacuum residue oil, extra-heavy crude oil, heavy crude oil, and oil sands bitumen.

[0072] Preferably, a heating furnace 6 is also connected downstream of the first hydrogen mixer 5-1. The heating furnace 6 is used to heat the mixed low-quality oil feedstock containing catalyst with hydrogen.

[0073] The bottom of the slurry bed reactor 7 is connected to the heater 6. The mixed low-quality oil feedstock containing catalyst and hydrogen undergo a preliminary hydrocracking reaction in the slurry bed reactor 7.

[0074] The online analysis device 8 is connected to the top of the first hydrogen mixer 5-1 and the slurry bed reactor 7. The online analysis device 8 is used to analyze the properties of the products from the slurry bed reactor 7 and detect whether they are qualified. If qualified, they enter the high-pressure separator 9 for separation to obtain liquid and gaseous products; if unqualified, they return to the first hydrogen mixer 5-1, are mixed with fresh feedstock, and then undergo preliminary hydrocracking reaction again in the slurry bed reactor 7.

[0075] Preferably, the online analysis device includes an online density meter, a rapid analyzer for toluene insolubles, and a signal transmission and control computer, which adjusts the reaction process parameters in a timely manner by controlling the density of the reaction products and the amount of coke produced.

[0076] The gaseous products are dehydrated by the hydrogen compressor and returned to the first hydrogen mixer 5-1 via the circulating hydrogen compressor 18 through the buffer tank 17.

[0077] Preferably, a second hydrogen mixer 5-2 is also included, which is located between the high-pressure separator 9 and the slurry reactor 11, and is used to mix the liquid phase product with hydrogen.

[0078] The liquid-phase product is mixed with hydrogen supplied by the new hydrogen compressor 19 via the pressure reducing valve 10 in the second hydrogen mixer 5-2 and then enters the slurry reactor 11 for deep hydrocracking of inferior oil. This invention does not particularly limit the number of slurry reactors 11. Preferably, there are multiple slurry reactors 11, preferably 4-6. The number of slurry reactors 11 meets the continuous operation requirements of processing the pretreatment reaction product of the slurry bed reactor 7 for inferior oil and providing raw materials for the fixed bed refining reactor 14. The operating conditions are: reaction temperature 400-430℃, reaction pressure 18.0-22.0 MPa, reaction time 0.5-2 h, and stirring rate 10-60 r / min.

[0079] Preferably, the height-to-diameter ratio of the slurry reactor 11 is 2 to 15:1, and more preferably 5 to 10:1; the slurry reactor 11 is equipped with a stirring device inside, and a hydrogen injection port is provided at the top of the slurry reactor 11 for adjusting the reaction pressure and discharging all the reaction products after the reaction is completed.

[0080] Preferably, the reactor also includes a filter assembly 12, a gas-liquid separator 13, and a third hydrogen mixer 5-3, which are sequentially arranged between the slurry reactor and the fixed-bed refining reactor 14. The filter assembly 12 is used to remove large particulate impurities larger than 50 μm from the reaction coke. The gas-liquid separator 13 is used to separate the product after impurity removal into gas and liquid phases to obtain gaseous and liquid phase materials. The third hydrogen mixer 5-3 is used to mix the liquid phase material with hydrogen.

[0081] After the reaction product is filtered by filter group 12 to remove large particles of reaction coke larger than 50μm, it enters gas-liquid separator 13 for gas-liquid separation to obtain liquid phase product. After being mixed with hydrogen again by the third hydrogen mixer 5-3, it enters fixed bed refining reactor 14 for refining treatment to remove impurities such as sulfur, nitrogen, metals, and aromatics.

[0082] The present invention does not particularly limit the number of fixed-bed refining reactors 14. Multiple fixed-bed refining reactors 14 can be configured, preferably two. Each fixed-bed refining reactor 14 contains two or more catalyst beds, preferably three catalyst beds, and its operating conditions are: reaction temperature 300–380°C, reaction pressure 5.0–10.0 MPa, and volumetric hourly space velocity 1.5–2.5 h⁻¹. -1 The hydrogen-to-oil volume ratio is 300–500:1. The fixed-bed refining reactor 14 is periodically switched between operations to remove inferior oil from the slurry-bed hydrocracking system and perform coke burn-off regeneration and activation operations.

[0083] The fractionation unit includes a fractionating furnace 15, an atmospheric distillation column, a vacuum distillation column, and a fractionating column 16. The fractionating furnace 15 is connected to a fixed-bed refining reactor 14 and is used to heat the products from the fixed-bed refining reactor 14. The fractionating column 16 is connected to a first hydrogen mixer 5-1 and separates the products from the fixed-bed refining reactor 14 to obtain high-quality gasoline, diesel, and wax oil products, as well as hydrotreating tailings. The hydrotreating tailings are returned to the first hydrogen mixer 5-1, mixed with fresh feedstock, and then re-entered into a slurry-bed reactor 7 for preliminary hydrocracking. Preferably, an atmospheric distillation column is connected in series with a vacuum distillation column.

[0084] This invention also provides a method for hydrocracking of inferior oil in a slurry bed, which includes the following steps:

[0085] S1: The inferior oil feedstock containing the catalyst is heated by heat exchange, mixed with hydrogen in the first hydrogen mixer, heated by the heater, and then enters the slurry bed reactor for preliminary hydrocracking reaction.

[0086] S2: The reaction products from step S1 are tested by an online analysis device to determine if they are qualified. If qualified, they are separated in a high-pressure separator to obtain liquid and gaseous products. If unqualified, they are returned to the first hydrogen mixer, mixed with fresh feedstock, and then subjected to a preliminary hydrocracking reaction in a slurry bed reactor.

[0087] S3: The liquid product from step S2 and hydrogen enter the second hydrogen mixer. After mixing in the second hydrogen mixer, it enters the slurry reactor for deep hydrocracking of inferior oil.

[0088] S4: The reaction product from step S3 is filtered to remove large particulate impurities larger than 50μm of reaction coke. The liquid phase material obtained by the gas-liquid separator is mixed with circulating hydrogen in the third hydrogen mixer and then enters the fixed bed refining reactor for refining treatment to remove impurities such as sulfur, nitrogen, metals, and aromatics.

[0089] S5: The reaction products from step S4 are heated in a fractionation furnace and then separated in a fractionation unit to obtain high-quality gasoline, diesel and wax oil products and hydrotreated tailings fraction. The hydrotreated tailings fraction is returned to the first hydrogen mixer, mixed with fresh feedstock, and then undergoes preliminary hydrocracking reaction in a slurry bed reactor.

[0090] The present invention provides a first hydrogen mixer, a second hydrogen mixer, and a third hydrogen mixer in front of the slurry bed reactor, the slurry reaction vessel, and the fixed bed refining reactor, respectively, which can increase the dissolved hydrogen capacity of the inferior oil slurry bed hydrocracking system.

[0091] The present invention preferably uses a combination process of "slurry bed reactor + slurry reaction vessel + fixed bed refining reactor", which follows the idea of ​​stepwise cracking and stepwise removal of impurities, and finally achieves high conversion rate of residue oil and obtains fuel oil that meets the National VI standard and high-quality hydrocracking feedstock.

[0092] The present invention preferably employs a combination of filter arrays and fixed bed protective agent layers to remove impurities such as coke and solid particles contained in the reaction products in a stepwise manner.

[0093] The following provides a detailed description of the embodiments of the present invention: These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and processes. However, the scope of protection of the present invention is not limited to the following embodiments. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions.

[0094] Source of raw materials or equipment:

[0095] Information on raw materials and equipment is shown in the table below.

[0096]

[0097] Evaluation and analysis methods:

[0098] The evaluation and analysis methods are shown in the table below.

[0099]

[0100] Example 1

[0101] The design parameters of the slurry bed reactor used in this embodiment are as follows: the height H of the shell (the distance between the upper and lower flanges) is 2000mm, the diameter R of the shell is 200mm, 6 sets of spiral fins are selected, the distance between two spiral fins is 1%H (i.e., 20mm), the width of the spiral fins is 5%R (i.e., 10mm), and the thickness of the spiral fins is 1mm; the interior of the inner empty tank is equipped with an electrically heated salt bath module to provide auxiliary heating for the slurry bed reactor and increase the internal temperature of the slurry bed reactor by 50℃; the outer wall of the inner empty tank is equipped with two symmetrically distributed temperature gauges to monitor the temperature inside the slurry bed reactor.

[0102] The reactants are mixed with hydrogen in the first hydrogen mixer and then fed into the slurry bed reactor through the reactor inlet. The reactants flow spirally upwards along the flow channels formed by the spiral fins into the slurry bed reactor for the initial hydrocracking reaction. The reaction temperature is 380℃, the reaction pressure is 14.0 MPa, and the volume hourly space velocity (VHSV) is 1.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 500. After the reaction products are analyzed and tested by an online analysis device and pass the test, they enter a high-pressure separator to separate the products into liquid and gaseous phases.

[0103] After the liquid product is mixed with hydrogen from the second hydrogen mixer, it undergoes deep hydrocracking of inferior oil in a slurry reactor. In this embodiment, four slurry reactors with a height-to-diameter ratio of 5:1 are used. The reaction temperature is 400°C, the reaction pressure is 18.0 MPa, and the reaction time is 2.0 h.

[0104] The product from the slurry reactor is mixed with hydrogen from the third hydrogen mixer and then fed into a fixed-bed refining reactor for refining. This embodiment uses two fixed-bed refining reactors, each containing three catalyst beds. The reaction temperature is 300°C, the reaction pressure is 5 MPa, and the volume hourly space velocity (VHSV) is 1.5 h⁻¹. -1 The hydrogen-to-oil volume ratio is 300. The reaction products are fed into a fractionation tower for separation to obtain high-quality products. The remaining hydrocracking tailings are returned to the first hydrogen mixer, mixed with fresh feedstock, and then subjected to a preliminary hydrocracking reaction in a slurry bed reactor.

[0105] This embodiment uses a process flow of one slurry bed reactor connected to four parallel slurry reaction vessels, followed by two parallel fixed-bed refining reactors. The process conditions are shown in Table 2.

[0106] Example 2

[0107] The design parameters of the slurry bed reactor used in this embodiment are as follows: the height H of the shell (distance between the upper and lower flanges) is 2000mm, the diameter R of the shell is 200mm, four sets of spiral fins are selected, the distance between two spiral fins is 2.5%H (i.e., 50mm), the width of the spiral fins is 7.5%R (i.e., 15mm), and the thickness of the spiral fins is 2mm; the interior of the inner empty tank is equipped with two electrically heated salt bath modules to provide auxiliary heating for the slurry bed reactor and increase the internal temperature of the slurry bed reactor to 100℃; the outer wall of the inner empty tank is equipped with four symmetrically distributed temperature gauges to monitor the temperature inside the slurry bed reactor.

[0108] The reactants are mixed with hydrogen in the first hydrogen mixer and then fed into the slurry bed reactor through the reactor inlet. The reactants flow spirally upwards along the flow channels formed by the spiral fins into the slurry bed reactor for the initial hydrocracking reaction. The reaction temperature is 390℃, the reaction pressure is 16.0 MPa, and the volume hourly space velocity (VHSV) is 2.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 800. After the reaction products are analyzed and tested by an online analysis device and pass the test, they enter a high-pressure separator to separate the products into liquid and gaseous phases.

[0109] After the liquid product is mixed with hydrogen from the second hydrogen mixer, it undergoes deep hydrocracking of inferior oil in a slurry reactor. In this embodiment, five slurry reactors with a height-to-diameter ratio of 7.5:1 are used. The reaction temperature is 415°C, the reaction pressure is 20.0 MPa, and the reaction time is 1.0 h.

[0110] The product from the slurry reactor is mixed with hydrogen from the third hydrogen mixer and then fed into a fixed-bed refining reactor for refining. This embodiment uses two fixed-bed refining reactors, each containing three catalyst beds. The reaction temperature is 340°C, the reaction pressure is 7 MPa, and the volumetric hourly space velocity (VHSV) is 2.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 350. The reaction products are fed into a fractionation tower for separation to obtain high-quality products. The remaining hydrocracking tailings are returned to the first hydrogen mixer, mixed with fresh feedstock, and then subjected to a preliminary hydrocracking reaction in a slurry bed reactor.

[0111] This embodiment uses a process flow of one slurry bed reactor connected to five parallel slurry reaction vessels, followed by two parallel fixed-bed refining reactors. The process conditions are shown in Table 2.

[0112] Example 3

[0113] The design parameters of the slurry bed reactor used in this embodiment are as follows: the height H of the shell (distance between the upper and lower flanges) is 2000mm, the diameter R of the shell is 200mm, two sets of spiral fins are selected, the distance between the two spiral fins is 5%H (i.e., 100mm), the width of the spiral fins is 10%R (i.e., 20mm), and the thickness of the spiral fins is 3mm; the interior of the inner empty tank is equipped with three electrically heated salt bath modules to provide auxiliary heating for the slurry bed reactor and increase the internal temperature of the slurry bed reactor by 150℃; the outer wall of the inner empty tank is equipped with six symmetrically distributed temperature gauges to monitor the temperature inside the slurry bed reactor.

[0114] The reactants are mixed with hydrogen in the first hydrogen mixer and then fed into the slurry bed reactor through the reactor inlet. The reactants flow spirally upwards along the flow channels formed by the spiral fins into the slurry bed reactor for the initial hydrocracking reaction. The reaction temperature is 400℃, the reaction pressure is 18.0 MPa, and the volume hourly space velocity (VHSV) is 3.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 1000. After the reaction products are analyzed and tested by an online analysis device and pass the test, they enter a high-pressure separator to separate the products into liquid and gaseous phases.

[0115] After the liquid product is mixed with hydrogen from the second hydrogen mixer, it undergoes deep hydrocracking of inferior oil in a slurry reactor. In this embodiment, six slurry reactors with a height-to-diameter ratio of 10:1 are used. The reaction temperature is 430°C, the reaction pressure is 22.0 MPa, and the reaction time is 0.5 h.

[0116] The product from the slurry reactor is mixed with hydrogen from the third hydrogen mixer and then fed into a fixed-bed refining reactor for refining. This embodiment uses four fixed-bed refining reactors, each containing three catalyst beds. The reaction temperature is 380°C, the reaction pressure is 10 MPa, and the volume hourly space velocity (VHSV) is 2.5 h⁻¹. -1 The hydrogen-to-oil volume ratio is 500. The reaction products are fed into a fractionation tower for separation to obtain high-quality products. The remaining hydrocracking tailings are returned to the first hydrogen mixer, mixed with fresh feedstock, and then subjected to a preliminary hydrocracking reaction in a slurry bed reactor.

[0117] This embodiment uses a process flow of one slurry bed reactor connected to six parallel slurry reaction vessels, followed by four parallel fixed-bed refining reactors. The process conditions are shown in Table 2.

[0118] Example 4

[0119] The design parameters of the slurry bed reactor used in this embodiment are as follows: the height H of the shell (the distance between the upper and lower flanges) is 2000mm, the diameter R of the shell is 200mm, 6 sets of spiral fins are selected, the distance between two spiral fins is 1%H (i.e., 20mm), the width of the spiral fins is 5%R (i.e., 10mm), and the thickness of the spiral fins is 1mm; the interior of the inner empty tank is equipped with an electrically heated salt bath module to provide auxiliary heating for the slurry bed reactor and increase the internal temperature of the slurry bed reactor by 50℃; the outer wall of the inner empty tank is equipped with two symmetrically distributed temperature gauges to monitor the temperature inside the slurry bed reactor.

[0120] The reactants are mixed with hydrogen in the first hydrogen mixer and then fed into the slurry bed reactor through the reactor inlet. The reactants flow spirally upwards along the flow channels formed by the spiral fins into the slurry bed reactor for the initial hydrocracking reaction. The reaction temperature is 380℃, the reaction pressure is 14.0 MPa, and the volume hourly space velocity (VHSV) is 1.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 500. After the reaction products are analyzed and tested by an online analysis device and pass the test, they enter a high-pressure separator to separate the products into liquid and gaseous phases.

[0121] After the liquid product is mixed with hydrogen from the second hydrogen mixer, it undergoes deep hydrocracking of inferior oil in a slurry reactor. In this embodiment, two slurry reactors with a height-to-diameter ratio of 5:1 are used. The reaction temperature is 400℃, the reaction pressure is 18.0MPa, and the reaction time is 2.0h.

[0122] The product from the slurry reactor is mixed with hydrogen from the third hydrogen mixer and then fed into a fixed-bed refining reactor for refining. In this embodiment, one fixed-bed refining reactor is used, comprising three catalyst beds. The reaction temperature is 300°C, the reaction pressure is 5 MPa, and the volume hourly space velocity (VHSV) is 1.5 h⁻¹. -1 The hydrogen-to-oil volume ratio is 300. The reaction products are fed into a fractionation tower for separation to obtain high-quality products. The remaining hydrocracking tailings are returned to the first hydrogen mixer, mixed with fresh feedstock, and then subjected to a preliminary hydrocracking reaction in a slurry bed reactor.

[0123] This embodiment uses a process flow of one slurry bed reactor connected to two parallel slurry reaction vessels, and one fixed bed refining reactor connected after the slurry reaction vessels. The process conditions used are shown in Table 2.

[0124] Comparative Example 1

[0125] Comparative Example 1 illustrates a conventional residue oil slurry-bed hydrocracking process operating with a single slurry-bed reactor without internal components, excluding the slurry reactor and fixed-bed refining reactor. The process flow can be found in [link to process flow diagram]. Figure 3 Under high temperature (445℃), high pressure (20MPa), and low air velocity (0.8h) conditions... -1 Under process conditions of high hydrogen-to-oil ratio (1200:1), hydrocracking reaction is carried out. The reaction products are separated into high- and low-volume fractions, then heated in a fractionating furnace and then passed through a fractionating tower to obtain various fraction products.

[0126] Comparative Example 2

[0127] Comparison 2 is a conventional residue oil slurry bed hydrocracking process using a single-stage series operation of two slurry bed reactors without internal components, at a reaction temperature of 430℃, a reaction pressure of 18MPa, and a low space velocity (1.0 h⁻¹). -1Under the process conditions of a high hydrogen-to-oil ratio (>800:1), a continuous hydrocracking process is carried out in two slurry bed reactors. The product of the first reaction is directly fed into the second reaction without separation. The product of the second reaction is separated into high- and low-volume fractions and then fed into a fractionating furnace for heating before being fed into a fractionating tower to obtain various fraction products.

[0128] Comparative Example 3

[0129] The only difference between this comparative example and Example 4 is that this comparative example uses a slurry bed reactor without spiral fins, while the other devices and reaction parameters are the same as in Example 4.

[0130] The slurry-bed hydrocracking catalyst used in this invention is an oil-soluble, highly dispersed molybdenum-based catalyst. It does not require pre-sulfurization and can be used directly after heating to the activation temperature. The properties of the raw materials used in the examples and comparative examples are shown in Table 1.

[0131] Table 1 Properties of Crude Oil

[0132]

[0133]

[0134] The process conditions used in the examples and comparative examples are detailed in Table 2.

[0135] Table 2 Operating conditions for the examples and comparative examples

[0136]

[0137] The test results of the examples and comparative examples are shown in Table 3.

[0138] Table 3. Experimental Results

[0139]

[0140] As shown in Tables 1-3, the heavy oil conversion rate of Comparative Example 1, using a conventional residue slurry bed hydrocracking process with one slurry bed reactor without internal components, was 91.4%, and the coking rate was 7.5%. The heavy oil conversion rate of Comparative Example 2, using a conventional residue slurry bed hydrocracking process with two slurry bed reactors without internal components, was 92.1%, and the coking rate was 4.6%. The heavy oil conversion rate of Comparative Example 3, using a slurry bed reactor without spiral fins, was 92.8%, and the coking rate was 2.3%. The heavy oil conversion rate of Example 1, using the technical solution of this invention (slurry bed reactor with hollow internal components containing spiral fins + slurry reactor + fixed bed reactor), was 94.3%, and the coking rate was only 0.12%. The heavy oil conversion rate of Example 2 was 97.0%, and the coking rate was only 0.3%. The heavy oil conversion rate of Example 3 was 100%, and the coking rate was 0.91%. The heavy oil conversion rate of Example 4 was 94.1%, and the coking rate was 0.72%.

[0141] When using a conventional slurry bed process, using two slurry bed reactors has certain advantages over using one slurry bed reactor. Under conditions where the reaction severity is relatively reduced, the heavy oil conversion rate is slightly increased.

[0142] Compared with conventional residue oil slurry bed hydrocracking process, the method of this invention has significant advantages. In addition, due to the spiral fin configuration of this invention, the reaction severity is further reduced (both reaction temperature and reaction pressure are lower), while the properties of the whole distillate oil of this invention are good. Its sulfur, nitrogen, metal and other impurities are basically removed. The gasoline and diesel fractions obtained after fractionation can meet the China VI standard, and the light oil yield is high (>70%). The unit can operate continuously for more than 2500 hours.

[0143] Because this invention employs an optimized process method with multiple hydrogen mixers, multi-point hydrogen replenishment, staged reaction, and online control, and designs and adopts a combination scheme of "slurry bed pre-reactor + slurry reactor + fixed bed refining reactor", it achieves continuous and stable operation of the device under the premise of high conversion rate of inferior oil. It can directly produce high-quality vehicle fuel oil or chemical raw materials from inferior heavy oil, with no tailings discharge, and ultimately realizes a highly efficient and deep conversion process of inferior heavy oil.

[0144] The above embodiments are typical examples listed to illustrate the technical solution of the present invention in detail. The present invention shall be subject to the protection scope of the claims and the invention content, and shall not be limited by the described embodiments. Simple substitutions or modifications to the present invention shall still be within the protection scope of the present invention.

Claims

1. A slurry-bed hydrocracking system for inferior oil, characterized in that, include: The first hydrogen mixer is used to mix low-quality oil feedstock containing catalyst with hydrogen. A slurry bed reactor, wherein the first hydrogen mixer is connected to the bottom of the slurry bed reactor, and the mixed low-quality oil feedstock containing catalyst and hydrogen undergo a preliminary hydrocracking reaction in the slurry bed reactor; An online analysis device is connected to the top of the first hydrogen mixer and the slurry bed reactor. The online analysis device is used to analyze the properties of the products from the slurry bed reactor and detect whether they are qualified. A high-pressure separator, connected to the online analysis device, is used to separate qualified products into liquid and gaseous products. A slurry reactor, connected to the high-pressure separator, is used to perform deep hydrocracking of the liquid phase product into inferior oil. The second hydrogen mixer is located between the high-pressure separator and the slurry reactor, and is used to mix the liquid phase product with hydrogen. A fixed-bed refining reactor, connected to the slurry reactor, is used to refine the products of the slurry reactor. The third hydrogen mixer is located between the slurry reactor and the fixed-bed refining reactor. The third hydrogen mixer is used to mix liquid materials with hydrogen. as well as A fractionation unit is connected to the first hydrogen mixer and the fixed-bed refining reactor to separate the products of the fixed-bed refining reactor to obtain high-quality gasoline, diesel and wax oil products and hydrotreating tailings fraction. The hydrotreating tailings fraction is returned to the first hydrogen mixer, mixed with fresh feedstock, and then subjected to a preliminary hydrocracking reaction in the slurry bed reactor. The slurry bed reactor includes: case; The reactor outlet is located at the top of the shell. The reactor inlet is located at the bottom of the shell; and An internal empty tank is disposed within the shell. Helical fins are provided between the internal empty tank and the shell. The internal empty tank and the shell are connected in a helical manner via the helical fins to form an integral internal component. There are multiple helical fins, with the spacing between any two helical fins being 1-10% of the height of the slurry bed reactor; the thickness of the helical fins is 1-5 mm; and the width of the helical fins is 5-15% of the diameter of the slurry bed reactor. The housing is also provided with flanges at both ends, and the internal components can be disassembled when the flanges are opened.

2. The inferior oil slurry bed hydrocracking system according to claim 1, characterized in that, The number of spiral fins is multiple, and the spacing between any two spiral fins is 1 to 5% of the height of the slurry bed reactor; the thickness of the spiral fins is 1 to 3 mm; and the width of the spiral fins is 5 to 10% of the diameter of the slurry bed reactor.

3. The inferior oil slurry bed hydrocracking system according to claim 1, characterized in that, The reactants are fed into the reactor inlet and flow spirally upwards into the slurry bed reactor along the material flow channels formed by the spiral fins for reaction; the reaction temperature is 380~400℃, the reaction pressure is 14.0~18.0MPa, and the volume hourly space velocity is 1.0~3.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 500-1000.

4. The inferior oil slurry bed hydrocracking system according to claim 1, characterized in that, The interior of the built-in empty tank is equipped with multiple electrically heated salt bath modules to provide auxiliary heating for the slurry bed reactor and increase the internal temperature of the slurry bed reactor by 50~150℃; the outer wall of the built-in empty tank is equipped with multiple symmetrically distributed temperature gauges to monitor the temperature inside the slurry bed reactor.

5. The inferior oil slurry bed hydrocracking system according to claim 4, characterized in that, The number of temperature-controlled instruments is two.

6. The inferior oil slurry bed hydrocracking system according to claim 1, characterized in that, It also includes a heating furnace, which is located between the first hydrogen mixer and the slurry bed reactor, for heating the mixed low-quality oil feedstock containing the catalyst with hydrogen.

7. The inferior oil slurry bed hydrocracking system according to claim 1, characterized in that, It also includes a filter assembly and a gas-liquid separator, which are located between the slurry reactor and the fixed-bed refining reactor; the filter assembly is used to remove large particulate impurities of reaction coke larger than 50µm; the gas-liquid separator is used to separate the product after impurity removal into gas and liquid phases to obtain gaseous and liquid phase materials.

8. The inferior oil slurry bed hydrocracking system according to claim 1, characterized in that, The number of slurry reactors is multiple; the number of slurry reactors meets the continuous operation requirements for processing the pretreatment reaction products of the slurry bed reactor for low-quality oil and providing raw materials for the fixed bed refining reactor. The operating conditions are: reaction temperature 400~430℃, reaction pressure 18.0~22.0MPa, reaction time 0.5-2h, stirring speed 10-60r / min; the height-to-diameter ratio of the slurry reactor is 2~15:1; the slurry reactor is equipped with a stirring device inside, and a hydrogen injection port is provided at the top of the slurry reactor for adjusting the reaction pressure and discharging all reaction products after the reaction is completed.

9. The inferior oil slurry bed hydrocracking system according to claim 8, characterized in that, The number of slurry reactors is 4-6.

10. The inferior oil slurry bed hydrocracking system according to claim 8, characterized in that, The height-to-diameter ratio of the slurry reactor is 5~10:

1.

11. The inferior oil slurry bed hydrocracking system according to claim 1, characterized in that, The number of fixed-bed refining reactors is multiple; each fixed-bed refining reactor contains two or more catalyst beds, and its operating conditions are: reaction temperature 300~380℃, reaction pressure 5.0~10.0MPa, and volumetric hourly space velocity 1.5~2.5h⁻¹. -1 The hydrogen-to-oil volume ratio is 300-500:1; the fixed-bed refining reactor is switched periodically for use, and the fixed-bed refining reactor of the inferior oil slurry bed hydrocracking system is cut off to perform coke burning regeneration and activation operations.

12. The inferior oil slurry bed hydrocracking system according to claim 11, characterized in that, The number of fixed-bed refining reactors is two.

13. The inferior oil slurry bed hydrocracking system according to claim 11, characterized in that, The fixed-bed refining reactor comprises three catalyst beds.

14. The inferior oil slurry bed hydrocracking system according to claim 1, characterized in that, The online analysis device includes an online density meter, a rapid analyzer for toluene insolubles, and a signal transmission and control computer. It adjusts the reaction process parameters in a timely manner by controlling the density of the reaction products and the amount of coke produced.

15. The inferior oil slurry bed hydrocracking system according to claim 1, characterized in that, The fractionation apparatus includes a fractionation furnace, an atmospheric distillation column, a vacuum distillation column, and a fractionation tower. The fractionation furnace is connected to the fixed-bed refining reactor, and the fractionation tower is connected to the first hydrogen mixer.

16. The inferior oil slurry bed hydrocracking system according to claim 15, characterized in that, The fractionation unit comprises an atmospheric distillation column connected in series with a vacuum distillation column.

17. The inferior oil slurry bed hydrocracking system according to claim 1, characterized in that, The catalyst includes a carrier oil, which is at least one of the following: catalytic diesel oil rich in aromatic hydrocarbons and cycloalkanes, coking diesel oil, hydrocracked diesel oil, and coking wax oil; the inferior oil feedstock is at least one of the following: catalytic slurry oil, high sulfur and nitrogen residue oil, high metal residue oil, high residual carbon residue oil, atmospheric residue oil, vacuum residue oil, extra-heavy crude oil, heavy crude oil, and oil sands asphalt.

18. A method for hydrocracking of inferior oil in a slurry bed, characterized in that, The inferior oil slurry bed hydrocracking system according to any one of claims 1-17, the inferior oil slurry bed hydrocracking method includes the following steps: S1: The inferior oil feedstock containing the catalyst is heated by heat exchange, mixed with hydrogen in the first hydrogen mixer, heated by the heater, and then enters the slurry bed reactor for preliminary hydrocracking reaction. S2: The reaction products from step S1 are tested by an online analysis device to see if they are qualified. If they are qualified, they are separated in a high-pressure separator to obtain liquid and gaseous products. If they are not qualified, they are returned to the first hydrogen mixer, mixed with fresh feedstock, and then subjected to a preliminary hydrocracking reaction in a slurry bed reactor. S3: The liquid product from step S2 and hydrogen enter the second hydrogen mixer. After mixing in the second hydrogen mixer, it enters the slurry reactor for deep hydrocracking of inferior oil. S4: The reaction product from step S3 is filtered to remove large particulate impurities of reaction coke larger than 50µm. The liquid phase material obtained by the gas-liquid separator is mixed with circulating hydrogen in the third hydrogen mixer and then enters the fixed bed refining reactor for refining treatment to remove sulfur, nitrogen, metal and aromatic impurities. S5: The reaction products from step S4 are heated and separated by a fractionation unit to obtain high-quality gasoline, diesel and wax oil products and hydrotreating tailings fraction. The hydrotreating tailings fraction is returned to the first hydrogen mixer, mixed with fresh feedstock, and then subjected to preliminary hydrocracking reaction in a slurry bed reactor.

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