A processing method for deep desulfurization and dearomatization of diesel fraction
By setting up a multi-zone reaction zone and a combination of different catalysts in the diesel fraction treatment, the energy consumption and operation difficulty of deep desulfurization of diesel fractions and aromatic saturation in the prior art are solved, and low-energy consumption and high-efficiency diesel fraction treatment is achieved. Meet the PAH content requirements of the National VI standard.
Patent Information
- Application Number
- CN202210420578.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-04-21
- Publication Date
- 2024-12-06
- Estimated Expiration
- 2042-04-21
AI Technical Summary
The prior art is difficult to efficiently perform deep desulfurization and aromatic saturation of diesel fractions under low energy consumption and low hydrogen usage conditions, and the device process is complex and operation is difficult, so it cannot meet the polycyclic aromatic hydrocarbon content requirements of the National VI diesel standard.
By setting up gas phase, gas-liquid countercurrent and liquid phase reaction zones in fixed bed reactors, loading different types of catalysts separately, controlling the reaction conditions and use of hydrogen, the partitioning of diesel fractions is realized, including hydrodesulfurization and gas in the gas phase reaction zone, and gas Desulfurization and aromatic hydrocarbon saturation in the liquid countercurrent zone, and deep polycyclic aromatic hydrocarbon saturation in the liquid phase reaction zone, optimizing mass transfer and thermodynamic conditions in the reaction zone.
It has achieved efficient desulfurization and aromatic saturation of diesel fractions under low energy consumption and low hydrogen usage, simplified the process flow, reduced equipment investment, met the PAH content requirements of the National VI diesel standard, and improved product quality and reaction efficiency.
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Figure CN116970419B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of oil refining and chemical industry, and specifically relates to a processing method for deep desulfurization and dearomatization of diesel fraction. Background Art
[0002] Currently, the raw materials of various refineries are getting worse and worse, and the quality of diesel fractions is also gradually deteriorating, mainly due to the high content of sulfides, nitrides and polycyclic aromatic hydrocarbons. This is bound to cause tremendous pressure on subsequent processing and conversion. It is difficult to produce diesel products with more stringent product quality requirements by direct processing using existing technical means.
[0003] A high aromatic content in diesel will reduce the quality of the oil, causing incomplete combustion of the fuel. The exhaust gas contains a large number of tiny particles, which not only causes serious pollution to the environment, but also harms people's health. Therefore, while meeting the ultra-deep desulfurization of diesel, reducing the aromatic content in diesel is the first problem that needs to be solved in the production of high-quality clean diesel.
[0004] US5114562A discloses a two-stage process for hydrodesulfurization and aromatic saturation of intermediate distillate oil. The method has two independent reactors. The first reactor performs hydrodesulfurization. The desulfurized product enters the stripping tower, where the H2S and NH3 generated by the reaction are removed by hydrogen stripping, and then enters the second reactor for hydrogenation saturation of aromatics. The method is relatively mature, but the saturation of aromatics in oil products is not selective. Under this condition, monocyclic aromatics are also prone to deep saturation, resulting in high hydrogen consumption in the reaction and high energy consumption of the device. In addition, the process of the device is complicated, the operation is difficult, and the equipment construction investment is large.
[0005] CN1488715A discloses a method for deep hydrodesulfurization and dearomatization of diesel. It adopts two reaction zones, can fully utilize the reaction heat, and does not need to take heat or add cold medium for cooling treatment, thus saving resources and costs. However, this processing method can only process raw materials with low aromatic content, or the polycyclic aromatic hydrocarbons content in the product does not meet the index requirements of polycyclic aromatic hydrocarbons in National VI diesel. Summary of the invention
[0006] In view of the shortcomings of the prior art, the present invention proposes a processing method for deep desulfurization and dearomatization of diesel fractions. The present invention sets different reaction zones and changes the passage path of the raw materials in the reactor. According to the composition characteristics of different fractions of diesel from light to heavy, the reaction phase and reaction type can be set in different zones and the product quality can be controlled. The diesel fraction oil products can be subjected to efficient hydrodesulfurization reaction and aromatic saturation reaction under low energy consumption and low hydrogen usage conditions to produce high-quality diesel blending components that meet the National VI standard.
[0007] The processing method for deep desulfurization and dearomatization of diesel fraction of the present invention comprises the following contents:
[0008] From top to bottom, the fixed bed reactor includes a gas phase reaction zone, a gas-liquid separation zone, a gas-liquid countercurrent zone, a gas-liquid mixing zone and a liquid phase reaction zone;
[0009] The diesel fraction feedstock and hydrogen enter the gas-liquid separation zone and the gas-liquid mixing zone respectively;
[0010] In the gas-liquid separation zone, the diesel fraction raw material is partially converted into a gas-phase light fraction under certain conditions and flows upward into the gas-phase reaction zone, while part of the unconverted liquid-phase heavy fraction flows downward into the gas-liquid countercurrent zone;
[0011] In the gas-liquid mixing zone, under certain conditions, part of the hydrogen is mixed and dissolved in the hydrogenation product in the gas-liquid countercurrent zone to form a mixed hydrogen material that flows downward into the liquid phase reaction zone, and part of the undissolved hydrogen flows upward in sequence through the gas-liquid countercurrent zone, the gas-liquid separation zone and the gas phase reaction zone to supply hydrogen to the above zones;
[0012] The gas phase reaction zone is filled with a light distillate oil hydrogenation catalyst, and the gas phase light distillate from the gas-liquid separation zone and the light components in the gas-liquid countercurrent zone are contacted with hydrogen to carry out a hydrodesulfurization reaction, and the gas phase reaction product flows out from the top of the reactor;
[0013] In the gas-liquid countercurrent zone, a hydrorefining catalyst is loaded, and the liquid heavy fraction from the gas-liquid separation zone and hydrogen undergo hydrodesulfurization, denitrogenation and partial aromatic saturation reactions;
[0014] The liquid phase reaction zone is filled with a hydrogenation dearomatization catalyst, and the mixed hydrogen material from the gas-liquid countercurrent zone undergoes a deep polycyclic aromatic hydrocarbon saturation reaction, and the liquid phase reaction product flows out from the bottom of the reactor.
[0015] In the method of the present invention, the diesel fraction oil raw material has a distillation range of generally 100-400°C, S≯10000μg / g, N≯5000μg / g, and a content of bicyclic and polycyclic aromatic hydrocarbons of 5-40%.
[0016] In the method of the present invention, the gas-liquid separation zone is used to separate the naphtha fraction from the raw material and the gas phase components ascending from the gas-liquid countercurrent zone to enter the gas phase reaction zone in the gas phase state, and the diesel fraction enters the gas-liquid countercurrent zone in the liquid phase. The operating conditions of the gas-liquid separation zone are pressure 2.0~10.0MPa, preferably 4.0~7.0MPa, wherein the hydrogen partial pressure accounts for 40%~80% of the total pressure; the feed temperature is 200~400℃, preferably 250~350℃; the hydrogen-oil volume ratio is 10:1~800:1, preferably 100:1~500:1.
[0017] In the method of the present invention, the gas phase reaction zone is used for the desulfurization reaction of the naphtha fraction in the gas phase to produce the small molecular fraction. The first reaction zone is loaded with a light distillate oil hydrogenation catalyst, the catalyst active metal is a VIB group metal oxide and / or a VIII group metal oxide, the VIB group metal is preferably Mo and / or W, the VIII group metal is preferably Co and / or Ni, the carrier is alumina or modified alumina, based on the weight of the catalyst, the VIB group metal oxide content is 5%-30%, preferably 5%-20%, and the VIII group metal oxide content is 1%-15%, preferably 2%-6%. The FH-40 series catalyst developed by FRIPP is preferred. Based on the total catalyst loading in the reactor, the catalyst loading volume ratio in the gas phase reaction zone is 5%~40%, preferably 10%~30%. The operating conditions of the gas phase reaction zone are generally: pressure 0.1~6.0MPa, preferably 2.0~5.0MPa, where the hydrogen partial pressure accounts for 30%~70% of the total pressure; volume space velocity 0.1~10.0h -1 , preferably 0.5~6.0h -1 ; Reaction temperature 150~300℃, preferably 180~260℃; Hydrogen-oil volume ratio 10:1~500:1, preferably 100:1~300:1.
[0018] In the method of the present invention, the gas-liquid countercurrent zone is used for deep desulfurization, denitrification and partial aromatics hydrogenation reaction of the liquid phase components descending from the gas-liquid separation zone. The gas-liquid countercurrent zone is loaded with a hydrorefining catalyst, and the catalyst active metal is a metal oxide of Group VIB and / or a metal oxide of Group VIII. The metal of Group VIB is preferably Mo and / or W, and the metal of Group VIII is preferably Co and / or Ni. Based on the weight of the catalyst, the content of the metal oxide of Group VIB is 5%-40%, preferably 15%-30%, and the content of the metal oxide of Group VIII is 1%-20%, preferably 2%-10%; the carrier is alumina or alumina modified with an additive, and the additive is one or more of B, P, Mg, etc. Based on the weight of the carrier, the additive is 1%-15% in terms of oxide, preferably 3%-10%. Such as the FHUDS series catalyst developed by FRIPP. The catalyst loading volume ratio in the gas-liquid countercurrent zone is 5~80%, preferably 30~60%. The operating conditions of the gas-liquid countercurrent zone are generally: pressure 3.0~10.0MPa, preferably 4.0~8.0MPa, wherein the hydrogen partial pressure accounts for 40%~80% of the total pressure; volume space velocity 0.1~10.0h -1 , preferably 0.5~3.0h -1 ; Reaction temperature 260~400℃, preferably 300~380℃; Hydrogen-oil volume ratio 10:1~400:1, preferably 100:1~300:1.
[0019] In the method of the present invention, the gas-liquid mixing zone is provided with a hydrogen inlet, and by flexibly controlling the parameters such as hydrogen flow rate and temperature, not only the countercurrent contact between the upward hydrogen and the downward liquid phase components is achieved, the two streams of materials are fully contacted, the mass transfer and heat exchange are enhanced, and the reaction requirements of the liquid phase reaction zone are met, while the upward hydrogen stripping removes the impurities such as H2S and NH3 generated by the gas-liquid countercurrent zone reaction, and controls the bed temperature stabilization, it can also avoid the poisoning of the hydrogenation dearomatization catalyst (precious metal catalyst) loaded in the liquid phase reaction zone. The operating conditions of the gas-liquid mixing zone are a pressure of 2.0~10.0MPa, preferably 5.0~8.0MPa, wherein the hydrogen partial pressure accounts for 100% of the total pressure; the feed temperature is 30~400℃, preferably 200~350℃.
[0020] In the method of the present invention, the liquid phase reaction zone is used for the mixed hydrogen material to undergo deep hydrogenation saturation reaction of aromatic hydrocarbons. The hydrogenation dearomatization catalyst loaded in the liquid phase reaction zone is a precious metal hydrogenation catalyst, which generally includes a carrier and an active component. The carrier is alumina, and the active component is Pt and / or Pd. Based on the weight of the catalyst, the active component is 0.05-5.0wt%; the precious metal hydrogenation catalyst can be the precious metal Pt-Pd catalyst SHPA2 published in Example 2 of CN109954490A. The catalyst loading volume ratio in the liquid phase reaction zone is 1~80%, preferably 30~60%. The operating conditions of the liquid phase reaction zone are generally: pressure 3.0~10.0MPa, preferably 4.0~8.0MPa, this is a pure liquid phase reaction zone, the volume ratio of standard hydrogen to oil is 2~300, preferably 10~200; volume space velocity 0.1~8.0h -1 , preferably 0.5~3.0h -1 ; Reaction temperature 200~400℃, preferably 250~330℃.
[0021] Compared with the prior art, the present invention has the following advantages:
[0022] The present invention realizes a zoned reaction with enhanced regional functions: the diesel fraction is fractioned in the gas-liquid separation zone, wherein the lighter fraction below 230°C enters the gas phase reaction zone as a gas phase component, and this fraction is mainly enriched with small molecular hydrocarbons, monocyclic aromatic hydrocarbons and small molecular sulfides, and the sulfides in this fraction section are all small molecular sulfides that are relatively easy to remove. By loading a catalyst with good direct desulfurization activity in this area, a direct desulfurization reaction can be achieved, and hydrogenation of monocyclic aromatic hydrocarbons in the material can be avoided, thereby reducing hydrogen consumption.
[0023] Hydrocarbons in the fraction above 230°C, including dicyclic and tricyclic aromatic hydrocarbons and macromolecular sulfides, nitrides and liquid phase components, flow downward into the gas-liquid countercurrent zone, and are converted into cyclic monocyclic aromatic hydrocarbons through desulfurization, denitrification and partial hydrogenation of dicyclic aromatic hydrocarbons. After hydrogenation refining in the reaction zone, impurities such as sulfur and nitrogen in the material can be removed, ensuring that the material entering the liquid phase reaction zone does not contain hydrogen sulfide poisons that are easy to poison the precious metal catalyst, while increasing the concentration of dicyclic and polycyclic aromatic hydrocarbons, thereby improving the selectivity of the aromatic hydrogenation reaction of the catalyst in the liquid phase reaction zone;
[0024] The liquid components refined in the gas-liquid countercurrent zone are contacted with pure hydrogen in the gas-liquid mixing zone and then enter the liquid phase reaction zone. Since the concentration of aromatics is high, a more suitable reaction environment can be matched according to the hydrogenation dearomatization kinetics and thermodynamics to improve the reaction selectivity and conversion rate. At the same time, the hydrogen concentration in the product flowing out of the liquid phase reaction zone is low, and there is no need to cool down and separate excess hydrogen, which eliminates the heat exchange process in conventional technology and reduces equipment investment.
[0025] In the present invention, the gas phase, gas-liquid countercurrent, and liquid phase reaction zones are divided into gas-solid reaction zones, gas-liquid-solid reaction zones, and liquid-solid reaction zones from top to bottom. In the traditional gas-liquid-solid three-phase reaction, gas-phase hydrogen needs to penetrate the liquid-phase feedstock oil to reach the surface of the solid-phase catalyst, which is restricted by diffusion and greatly limits the reaction efficiency. In the present invention, in addition to the gas-phase and liquid-phase reaction zones being two-phase reactions with higher mass transfer efficiency, the gas-liquid countercurrent zone adopts gas-phase and liquid-phase reverse contact to strengthen the driving force of gas-liquid mass transfer, and the reaction efficiency is also significantly improved.
[0026] In the present invention, hydrogen can not only meet the chemical hydrogen consumption required for the reaction in each reaction zone, but also has a stripping effect due to the countercurrent flow contact with the reaction materials in the gas-liquid countercurrent zone, which can carry the H2S, NH3 and small molecule hydrocarbons generated by the reaction to the gas phase reaction zone in time, and flow out of the device from the top of the reactor, which not only eliminates the influence of H2S in the gas-liquid countercurrent zone on the deep hydrodesulfurization reaction, but also can improve the purity of hydrogen in the next reaction zone. The temperature and flow rate of the hydrogen feed can be flexibly adjusted according to the different requirements of the noble metal catalyst for the reaction environment at the beginning and end of the reaction. For example, the activity of the noble metal hydrogenation catalyst is relatively high at the beginning of the reaction, and the temperature required for the reaction is relatively low. By lowering the temperature of the hydrogen, or adjusting the feed amount of the hydrogen, the material flowing out of the gas-liquid countercurrent zone is subjected to countercurrent heat exchange, and the material entering the liquid phase reaction zone is cooled, thereby achieving the purpose of lowering the reaction temperature. The hydrogen inlet is set in the gas-liquid mixing zone below the gas-liquid countercurrent zone, where the hydrogen partial pressure is the highest, which is conducive to optimizing the deep desulfurization, denitrogenation and dearomatization reactions in the gas-liquid countercurrent zone, as well as the deep dearomatization reaction environment in the liquid phase reaction zone. In the gas-liquid mixing zone, the liquid phase components refined in the gas-liquid countercurrent zone are contacted with the high-purity hydrogen raw material again, and carry and dissolve a large amount of hydrogen and quickly enter the liquid phase reaction zone, avoiding the problem of hydrogen escaping after the conventional liquid phase hydrogenation process enters the reactor through mixed hydrogen, affecting the liquid phase hydrogen concentration and hydrogen utilization rate. Moreover, since the gas-liquid countercurrent zone is a deep hydrodesulfurization and denitrogenation process, the reaction will be accompanied by a large amount of reaction heat, and the solubility of hydrogen in the oil product increases with the increase of the reaction temperature. The arrangement of hydrogen feed below can greatly increase the amount of hydrogen dissolved in the oil product.
[0027] The three reaction zones designed by the present invention complement each other in terms of process conditions, and can maintain the stability of the reaction system to the greatest extent. The gas phase reaction zone is a gas phase reaction zone, which is a gas phase space, and the gas-liquid countercurrent zone is a gas-liquid countercurrent reaction zone. Through the reverse contact between the liquid material and the hydrogen, while strengthening the heat and mass transfer, a certain amount of back mixing will also be generated, and the existence of the gas phase reaction zone can provide a larger compressible space, which has a good buffering effect on the flow state of the material in the reaction system and the pressure of the stable bed. By flexibly adjusting the gas volume at the outlet, the gas phase flow rate and liquid layer thickness in the gas-liquid countercurrent zone can be controlled, and the upper limit of the liquid flooding rate can be increased. A large amount of hydrogen is carried and dissolved in the gas-liquid mixing zone into the liquid phase reaction zone, and a liquid phase hydrogenation reaction occurs. While the hydrogen required for the aromatic saturation reaction is dissolved in the reaction zone, the material can also control the logistics state of the reactor outlet in the liquid phase state, which will not cause the problem of hydrogen being carried out of the reactor without passing through the catalyst bed to react. Correspondingly, the high-pressure separator in the conventional process flow can be saved, simplifying the reaction process. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 The present invention is a schematic diagram of a production method for deep desulfurization and dearomatization of diesel fractions.
[0029] In the figure: 1-raw material, 2-hydrogen, 3-gas phase reaction zone, 4-gas-liquid countercurrent zone, 5-liquid phase reaction zone, 6-gas-liquid separation zone, 7-gas-liquid mixing zone, 8-gas phase reaction product, 9-liquid phase reaction product, 10-gasoline blending component, 11-diesel blending component. DETAILED DESCRIPTION
[0030] The present invention will be described in detail below with reference to the accompanying drawings and embodiments, but the present invention is not limited thereto.
[0031] Attach Figure 1 Taking the deep desulfurization and dearomatization process of a diesel fraction of the present invention as an example, the reaction raw material 1 enters the reactor from the gas-liquid separation zone 6. In the gas-liquid separation zone 6, it is separated into gas phase and liquid phase materials. The gas phase material flows upward into the gas phase reaction zone 3, and the liquid phase material flows downward into the gas-liquid countercurrent zone 4. Hydrogen 2 enters the hydrogenation reactor in the gas-liquid mixing zone 7, and after mixing and contacting with the liquid phase material flowing downward from the gas-liquid countercurrent zone 4, it flows upward into the gas-liquid countercurrent zone 4, and the liquid phase material carrying hydrogen flows downward into the liquid phase reaction zone 5.
[0032] A gas phase reaction occurs in the gas phase reaction zone 3, mainly a hydrodesulfurization reaction of hydrocarbon substances (mainly monocyclic aromatics, olefins, small molecular sulfides, etc.) below the dicyclic aromatics in the diesel fraction, to generate a gas phase reaction product 8, which is used as a gasoline blending component 10 after condensation. A gas-liquid two-phase reaction occurs in the gas-liquid countercurrent zone 4, the liquid diesel fraction flows downward, and the gas phase is hydrogen flows upward, and a deep hydrogenation refining reaction occurs through gas-liquid reverse contact. The H2S, NH3 and small molecular hydrocarbons generated by the reaction flow upward with the gas phase material into the gas-liquid separation zone 6 and the gas phase reaction zone 3, and finally flow out of the device from the top of the reactor. The liquid phase flow after the reaction in the gas-liquid countercurrent zone flows downward into the gas-liquid mixing zone 7, carrying hydrogen into the liquid phase reaction zone 5, and an aromatic hydrogenation saturation reaction occurs. The liquid phase reaction product 9 flows out of the device and enters the fractionation system to obtain the corresponding diesel blending component 11.
[0033] Embodiment 1~3
[0034] This embodiment adopts a 100mL fixed bed hydrogenation reactor, and a catalyst bed is set in the gas phase, gas-liquid countercurrent, and liquid phase reaction zones from top to bottom. Mo-Co type hydrorefining catalyst A is loaded in the gas phase reaction zone I, Mo-Ni type hydrorefining catalyst B is loaded in the gas-liquid countercurrent zone, and precious metal Pt-Pd catalyst C is loaded in the liquid phase reaction zone. Catalyst C is prepared according to the SHPA2 catalyst published in Example 2 in patent CN109954490A. The catalyst is loaded in a volumetric filling ratio of A: B: C = 25: 40: 35 according to the reactor volume. Straight-run diesel and catalytic diesel mixed oil are used as raw materials, and the mass ratio of straight-run diesel: catalytic diesel is 70: 30. Catalyst properties are shown in Table 1, crude oil properties are shown in Table 2, and reaction process conditions and results are shown in Table 3.
[0035] Comparative Example 1
[0036] The existing diesel hydrofining technology was used to introduce the raw materials into a 100mL pilot hydrofining device for hydrofining reaction, and the gasoline and diesel fractions after hydrogenation were obtained through gas stripping and condensation devices. The raw materials were the same as those in the embodiment, and the hydrofining reactor was filled with Mo-Co type hydrofining catalyst A with a filling volume of 50mL; the lower layer was filled with Mo-Ni type catalyst B with a filling volume of 50mL. The reaction conditions were the same as those in the gas-liquid countercurrent zone of Example 3.
[0037] Comparative Example 2
[0038] 100mL fixed bed reactor 1 and 100mL fixed bed reactor 2 are respectively set in series. Fixed bed reactor 1 is set with gas phase reaction zone and gas-liquid countercurrent zone from top to bottom and two catalyst beds are set. Fixed bed reactor 2 is used as liquid phase reaction zone, and a catalyst bed is set separately. Raw materials enter the reactor from the middle of the bed of fixed bed reactor 1, and hydrogen enters the reactor from the lower part of the lower bed of fixed bed reactor. The raw material properties are the same as those in the embodiment. The gas phase reaction zone of fixed bed reactor 1 is filled with 25mL Mo-Co type catalyst A, the gas-liquid countercurrent zone is filled with 40mL Mo-Ni type catalyst B, and the fixed bed reactor 2 is filled with 35mL precious metal Pt-Pd catalyst C. The reaction process conditions and results are shown in Table 3.
[0039] Table 1 Physicochemical properties of catalysts
[0040]
[0041] Table 2 Raw oil properties
[0042]
[0043] Table 3 Hydrogenation process conditions and results
[0044]
[0045] It can be seen from Table 3 that compared with the existing diesel hydrotreating and refining technology, this method can use a more scientific and reasonable process route and catalyst grading system to achieve the purpose of removing polycyclic aromatic hydrocarbons from diesel under milder operating conditions and produce high-quality gasoline and diesel blending components.
Claims
1. A method for deep desulfurization and dearomatization of diesel fraction, characterized in that The invention comprises the following contents: the fixed bed reactor is provided with a gas phase reaction zone, a gas-liquid separation zone, a gas-liquid countercurrent zone, a gas-liquid mixing zone and a liquid phase reaction zone from top to bottom; the diesel fraction raw material and hydrogen enter the gas-liquid separation zone and the gas-liquid mixing zone respectively; in the gas-liquid separation zone, the diesel fraction raw material is partially converted into a gas phase light fraction under certain conditions and enters the gas phase reaction zone upward, and part of the unconverted liquid phase heavy fraction enters the gas-liquid countercurrent zone downward; in the gas-liquid mixing zone, under certain conditions, part of the hydrogen is mixed and dissolved in the hydrogenation product of the gas-liquid countercurrent zone to form a mixed hydrogen material and enters the liquid phase reaction zone downward, and part of the undissolved hydrogen passes through the gas-liquid countercurrent zone, the gas-liquid separation zone and the gas phase reaction zone in turn upward to supply hydrogen to the above zones; in the gas phase reaction zone, light distillate oil is loaded for hydrogenation The catalyst, the gas phase light fraction from the gas-liquid separation zone, the light component from the gas-liquid countercurrent zone and hydrogen are contacted to carry out hydrodesulfurization reaction, and the gas phase reaction product flows out from the top of the reactor; the gas-liquid countercurrent zone is filled with a hydrorefining catalyst, and the liquid phase heavy fraction from the gas-liquid separation zone and hydrogen are subjected to hydrodesulfurization, denitrogenation and partial aromatic saturation reaction; the liquid phase reaction zone is filled with a hydrodearomatization catalyst, and the mixed hydrogen material from the gas-liquid countercurrent zone is subjected to deep polycyclic aromatic saturation reaction, and the liquid phase reaction product flows out from the bottom of the reactor; the diesel fraction raw material distillation range is 100-400°C, S≯10000μg / g, N≯5000μg / g, and the content of bicyclic and polycyclic aromatic hydrocarbons is 5-40%; the light distillate oil filled in the gas phase reaction zone A hydrogenation catalyst, wherein the catalyst active metal is a metal oxide of Group VIB and / or a metal oxide of Group VIII, the metal of Group VIB is Mo and / or W, the metal of Group VIII is Co and / or Ni, the carrier is alumina or modified alumina, based on the weight of the catalyst, the content of the metal oxide of Group VIB is 5%-30%, and the content of the metal oxide of Group VIII is 1%-15%; based on the total catalyst loading in the reactor, the catalyst loading volume ratio in the gas phase reaction zone is 5%-40%; the hydrogenation refining catalyst loaded in the gas-liquid countercurrent zone, wherein the active metal is a metal oxide of Group VIB and / or a metal oxide of Group VIII, the metal of Group VIB is Mo and / or W, the metal of Group VIII is The catalyst is a catalyst having a catalyst weight of 100 wt% and ...
2. The method according to claim 1, characterized in that: The operating conditions of the gas-liquid separation zone are as follows: pressure of 2.0-10.0 MPa, wherein the hydrogen partial pressure accounts for 40%-80% of the total pressure; feed temperature of 200-400°C; and hydrogen-oil volume ratio of 10:1-800:
1.
3. The method according to claim 1, characterized in that: The operating conditions of the gas phase reaction zone are: pressure 0.1~6.0MPa, of which the hydrogen partial pressure accounts for 30%~70% of the total pressure; volume space velocity 0.1~10.0h -1 ; Reaction temperature 150~300℃; Hydrogen-oil volume ratio 10:1~500:
1.
4. The method according to claim 1, characterized in that: The operating conditions of the gas-liquid countercurrent zone are: pressure 3.0~10.0MPa, where the hydrogen partial pressure accounts for 40%~80% of the total pressure; volume space velocity 0.1~10.0h -1 ; Reaction temperature 260~400℃; Hydrogen-oil volume ratio 10:1~400:
1.
5. The method according to claim 1, characterized in that: The operating conditions of the gas-liquid mixing zone are a pressure of 2.0-10.0 MPa, wherein the hydrogen partial pressure accounts for 100% of the total pressure; and a feed temperature of 30-400°C.
6. The method according to claim 1, characterized in that: The operating conditions of the liquid phase reaction zone are: pressure 3.0~10.0MPa, this is a pure liquid phase reaction zone, the volume ratio of standard hydrogen to oil is 2~300; the volume space velocity is 0.1~8.0h -1 ; Reaction temperature 200~400℃.