Hydrocarbon oil hydrotreating apparatus and method of use thereof

Abstract

A hydrocarbon oil hydrogenation treatment device and its application method, the device comprises a hydrogen mixing tank, a first reactor, a second reactor and a gas-liquid separation device, wherein the hydrogen mixing tank is provided with a liquid phase inlet and a gas phase inlet, the bottom outlet of the hydrogen mixing tank is communicated with the bottom inlet of the first reactor, at least one catalyst bed is arranged in the first reactor, the top outlet pipeline of the first reactor, the hydrogen supplement pipeline and the top inlet of the second reactor are communicated, the bottom outlet of the second reactor is communicated with the gas-liquid separation device, and the second reactor is provided with a catalyst bed. The hydrocarbon oil hydrogenation treatment device provided by the application is applied to a hydrocarbon oil hydrogenation reaction process, the operation conditions of two-stage hydrogenation reaction are conveniently controlled, the reaction depth and reaction heat release of two-stage reaction are controlled, the heat release amount of the trickle bed reaction section is reduced, the reaction temperature rise is reduced, the use amount of cooling circulating hydrogen is reduced, and the mass transfer and reaction efficiency are improved.

Description

Technical Field

[0001] This invention relates to reaction apparatus and reaction methods in the field of petrochemicals, and more specifically, to a hydrocarbon oil hydrotreating reaction apparatus and its operation control method. Background Technology

[0002] Hydrotreating technology can effectively remove impurities such as S, N, O, metals, and residual carbon from petrochemical products, as well as aromatics, olefins, and dienes from saturated or partially saturated hydrocarbon products. It also enables isomerization, cyclization, aromatization, and cracking of hydrocarbon molecules, playing a very important role in petrochemical production.

[0003] Currently, most hydrogenation processes employ traditional trickle bed technology. Since hydrogenation is largely exothermic, and to control reactor temperature and suppress side reactions such as catalyst carbon buildup, the conventional method is to circulate large quantities of hydrogen. This method requires a complex circulating hydrogen system, resulting in a larger reactor volume, which inevitably increases investment and operating energy consumption.

[0004] To overcome the shortcomings of the aforementioned trickle-bed hydrogenation technology, researchers have proposed liquid-phase hydrogenation technology. This technology dissolves hydrogen in the feedstock oil to meet the hydrogen requirements of the hydrogenation reaction, and then recirculates the liquid to dissolve sufficient hydrogen to satisfy the reaction's needs. The reaction takes place under liquid-phase conditions. Liquid-phase hydrogenation technology eliminates the need for a circulating compressor system, a high-efficiency separation system, and their associated equipment, significantly reducing investment and energy consumption. Furthermore, because liquid-phase hydrogenation technology eliminates the influence of catalyst wetting factors and utilizes the high specific heat capacity of the circulating oil, it improves catalyst utilization efficiency, greatly reduces reactor temperature rise, and minimizes side reactions such as cracking.

[0005] The main challenge in liquid-phase hydrogenation lies in the dissolution and replenishment of hydrogen. US patents US6213835 and US6428686 disclose a hydrogenation process in which fresh feedstock and a diluent are first mixed with a large amount of hydrogen. The diluent is a substance with high solubility for hydrogen, such as recycled hydrocracking products. The resulting mixture is then separated from excess gas by a gas-liquid separator before entering the reactor to contact the catalyst and react. Chinese patents CN101280217A, CN105647577A, and CN101787305A also employ similar processes, but different methods can be used for the premixing of hydrogen before the reactor. For example, CN105733662A proposes the use of a microbubble generator, CN103773441A uses a vortex mixer, a static mixer, or a jet mixer, and CN103666547A injects hydrogen into the hydrocarbon oil through through holes with an average pore size of nanometers to achieve high dispersion of hydrogen and dissolve it in the hydrocarbon oil at a relatively fast rate.

[0006] Of the two technologies mentioned above, trickle bed technology typically requires a large hydrogen circulation volume to control the heat of reaction, resulting in relatively high energy consumption. However, it also boasts high mass transfer and reaction efficiency due to its high fluid flow rate and low liquid film mass transfer resistance. Liquid-phase hydrogenation technology, on the other hand, does not require a gas compressor, has a smaller reactor volume, and utilizes a liquid-phase bulk endothermic reaction, leading to a smaller temperature rise. However, it also suffers from drawbacks such as high liquid-phase mass transfer resistance and insufficient primary hydrogen dissolution to meet chemical consumption requirements, thus limiting its application scope. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to address the problems existing in the existing trickle bed and liquid phase hydrogenation processes, and to provide a segmented hydrocarbon oil hydrogenation treatment device and its application method.

[0008] In a first aspect, the present invention provides a hydrocarbon oil hydrotreating apparatus, comprising a hydrogen mixing tank, a first reactor, a second reactor, and a gas-liquid separation device, wherein the hydrogen mixing tank is provided with a liquid phase inlet and a gas phase inlet, the bottom outlet of the hydrogen mixing tank is connected to the bottom inlet of the first reactor, at least one catalyst bed is provided in the first reactor, the top outlet of the first reactor and a supplementary hydrogen pipeline are connected to the top inlet of the second reactor, the bottom outlet of the second reactor is connected to the gas-liquid separation device, and the second reactor is provided with a catalyst bed.

[0009] Secondly, the present invention provides a method for treating hydrocarbon oil with hydrogenation. Using the aforementioned hydrocarbon oil hydrogenation apparatus, hydrogen gas enters a hydrogen mixing tank through a gas phase inlet and hydrocarbon oil feedstock through a liquid phase inlet. In the hydrogen mixing tank, hydrocarbon oil droplets contact hydrogen gas to achieve hydrogen saturation. The hydrogen-saturated hydrocarbon oil gathers at the bottom of the hydrogen mixing tank and enters a first reactor. The hydrocarbon oil, as a continuous phase, contacts the catalyst and undergoes a hydrogenation reaction. The hydrocarbon oil discharged from the top outlet of the first reactor mixes with replenished hydrogen gas and enters a second reactor from the top. Here, hydrogen gas is the continuous phase, and the hydrocarbon oil contacts the catalyst in a dripping form for further hydrogenation reaction, resulting in hydrogenated hydrocarbon oil.

[0010] The beneficial effects of the hydrocarbon oil hydrotreating reactor and application method provided by this invention are as follows:

[0011] Compared with the prior art, the segmented hydrocarbon oil hydrotreating device provided by the present invention combines a liquid phase hydrotreating reactor with a trickle bed hydrotreating reactor and is applied to the hydrocarbon oil hydrotreating reaction process. This facilitates the control of the operating conditions of the two-stage hydrotreating reaction. By controlling the reaction depth and reaction exothermics of the two stages, the heat exothermics of the trickle bed reaction stage are reduced, thereby reducing the reaction temperature rise, reducing the amount of cooling circulating hydrogen used, and improving mass transfer and reaction efficiency. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the hydrogenation reaction apparatus provided by the present invention;

[0013] Figure 2 This is a schematic diagram of the intermediate gas distributor in the hydrogenation reaction apparatus provided by the present invention.

[0014] in:

[0015] 1-Liquid inlet; 2-Spray-type liquid distributor; 3-Hydrogen main pipe

[0016] 4-Gas phase inlet; 5-Intermediate hydrogen pipeline; 6-Supplemental hydrogen pipeline

[0017] 7, 11 - Automatic flow regulating valve; 8 - Hydrogen mixing tank; 9 - Hydrogen mixing tank outlet.

[0018] 10 - Intermediate Gas Distributor; 12 - First Reactor Outlet; 13 - Second Reactor Outlet

[0019] 14-Gas-Liquid Separator 15-Gas Phase Product Extraction 16-Liquid Phase Product Extraction

[0020] Figure 3 This is a schematic diagram of the reaction process for Comparative Example 1.

[0021] Figure 4 This is a schematic diagram of the reaction process for Comparative Example 2. Detailed Implementation

[0022] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and do not limit the scope of the invention.

[0023] In a first aspect, the present invention provides a hydrocarbon oil hydrotreating apparatus, comprising a hydrogen mixing tank, a first reactor, a second reactor, and a gas-liquid separation device, wherein the hydrogen mixing tank is provided with a liquid phase inlet and a gas phase inlet, the bottom outlet of the hydrogen mixing tank is connected to the bottom inlet of the first reactor, at least one catalyst bed is provided in the first reactor, the top outlet of the first reactor and a supplementary hydrogen pipeline are connected to the top inlet of the second reactor, the bottom outlet of the second reactor is connected to the gas-liquid separation device, and the second reactor is provided with a catalyst bed.

[0024] In the device provided by the present invention, the hydrogen mixing tank is further equipped with a pressure detection device and a liquid level detection device; the pressure detection device signal is interlocked with the flow regulating valve on the hydrogen inlet pipeline through the control system to regulate the pressure inside the hydrogen mixing tank, and the liquid level detection device signal is interlocked with the flow regulating valve on the top outlet pipeline of the first reactor to regulate the liquid level height inside the hydrogen mixing tank through the control system.

[0025] Preferably, the liquid phase inlet is located at the top of the hydrogen mixing tank and is connected to a spray-type liquid distributor located inside the hydrogen mixing tank, and the gas phase inlet is connected to a gas distributor.

[0026] Preferably, the hydrogen mixing tank is filled with an oleophilic filler, which is polypropylene, polyvinyl chloride, polyvinylidene fluoride, polytetrafluoroethylene, or a surface-modified metal material.

[0027] In the preferred embodiment described above, a spray-type liquid distributor is used to micro-disperse the liquid-phase hydrocarbon oil feedstock in an independent hydrogen mixing tank. The hydrogen mixing tank is filled with oleophilic filler to obtain a large gas-liquid mass transfer surface area, thereby accelerating the dissolution and saturation of hydrogen in the hydrocarbon oil.

[0028] Preferably, the height-to-diameter ratio of the hydrogen mixing tank is 2-5:1, the height-to-diameter ratio of the first reactor is 10-30:1, the inner diameter ratio of the hydrogen mixing tank to the first reactor is 0.2-1.0:1, and the height-to-diameter ratio of the second reactor is 15-40:1.

[0029] Preferably, the first reactor is provided with two or more catalyst beds, and the intermediate hydrogen pipeline is connected to an intermediate gas distributor provided between adjacent catalyst beds;

[0030] Preferably, the gas distributor is a shell-and-tube structure, with multiple micro / nanoporous tubes uniformly arranged axially inside the cylindrical shell. These micro / nanoporous tubes open onto the top and bottom surfaces of the cylindrical shell, allowing the upper and lower catalyst beds to communicate through them. A gas inlet is provided on the cylindrical shell. Hydrogen gas passes through the pores in the micro / nanotube walls from the shell side and is dispersed into small bubbles, mixing with hydrocarbon oil within the tubes.

[0031] Preferably, the average pore size of the micro / nanoporous tube is <10 micrometers;

[0032] Preferably, the micro / nano porous tubes are arranged uniformly in a square or equilateral triangle pattern on the cross-section of the intermediate gas distributor, and the total area of ​​the tubes accounts for 30%-80% of the cross-sectional area of ​​the reactor.

[0033] Secondly, the present invention provides a method for treating hydrocarbon oil with hydrogenation, employing any of the aforementioned hydrocarbon oil hydrogenation devices. Hydrogen gas enters a hydrogen mixing tank through a gas phase inlet, and hydrocarbon oil feedstock enters through a feedstock inlet. In the hydrogen mixing tank, droplets come into contact with hydrogen gas to achieve hydrogen saturation. The hydrogen-saturated hydrocarbon oil gathers at the bottom of the hydrogen mixing tank and enters a first reactor from the bottom. The hydrocarbon oil, as a continuous phase, comes into contact with the catalyst to undergo a hydrogenation reaction. The hydrocarbon oil discharged from the top outlet of the first reactor mixes with replenished hydrogen gas and enters a second reactor from the top. Here, hydrogen gas is the continuous phase, and the hydrocarbon oil comes into contact with the catalyst in a dripping form for further hydrogenation reaction, resulting in hydrogenated hydrocarbon oil.

[0034] In the method provided by the present invention, hydrogen enters the hydrogen mixing tank through the gas phase inlet, and the hydrocarbon oil feedstock is dispersed into droplets with a diameter of less than 1.0 mm by a spray-type liquid distributor, and comes into contact with hydrogen until the dissolved hydrogen is saturated; preferably, the pressure drop before and after the spray-type liquid distributor is 0.1 MPa to 1.0 MPa.

[0035] Preferably, the hydrogen mixing tank is filled with lipophilic filler, and the hydrocarbon oil forms a thin liquid film on the surface of the lipophilic filler, which comes into contact with hydrogen until the hydrogen is saturated.

[0036] Preferably, the first reactor is provided with two or more catalyst beds. Hydrogen is sent between two adjacent catalyst beds through an intermediate hydrogen pipeline and distributed as microbubbles by an intermediate gas distributor to enter the hydrocarbon oil to replenish the reaction consumption.

[0037] Preferably, the operating conditions of the first and second reactors are: reaction temperature of 150℃~500℃, pressure of 1.0~25MPa, and total volume hourly space velocity of hydrocarbon oil of 0.1~20h. -1 The total hydrogen-to-oil volume ratio is 50–600, and the total hydrogen consumption for chemical reactions is 0.2 wt%–5.0 wt%.

[0038] Preferably, the flow rate ratio of hydrogen introduced into the hydrogen mixing tank, the first reactor, and the second reactor is (0.2-3.0):1.0:(1.0-10.0).

[0039] Preferably, the loading ratio of hydrogenation catalyst in the first reactor and the second reactor is 1:0.5-5, more preferably 1:1.5-3.

[0040] In the method provided by this invention, the hydrocarbon feedstock is selected from one or a mixture of several of C1-C4 light hydrocarbons, naphtha, gasoline, jet fuel, diesel, VGO, and residual oil. Preferably, it is selected from one or a mixture of several of jet fuel, diesel, VGO, and residual oil.

[0041] Preferably, the operating conditions of the first reactor and the second reactor are controlled to ensure that 60% to 95% of the total reaction conversion is completed in the first reactor and 5% to 40% of the total conversion reaction is completed in the second reactor.

[0042] In the method provided by this invention, the first and second reactors are filled with hydrogenation catalysts, which can be conventional hydrogenation catalysts, such as hydrogenation-active components supported on an inorganic heat-resistant oxide support. This invention does not limit this. The hydrogenation reaction can be a hydrogenation process requiring hydrogen gas, such as hydrogenation treatment, hydrogenation purification, hydrocracking, hydrogenation saturation, or hydroisomerization.

[0043] In one embodiment of the device provided by this invention, the hydrogen mixing tank is equipped with a liquid phase inlet pipeline and a spray-type liquid phase distributor at the top, and a gas phase inlet pipeline and a flow control valve at the bottom. A pressure detection device is installed at the top of the mixing tank, and a liquid level detection device is installed at the bottom. The hydrocarbon oil feedstock is dispersed into tiny droplets by the spray-type liquid distributor. The diameter of the hydrocarbon oil droplets is less than 1.0 mm. The droplets contact the hydrogen gas entering from the gas phase inlet pipeline and quickly reach hydrogen saturation. Preferably, the hydrogen mixing tank is filled with an oleophilic packing material. The packing material is selected from polypropylene, polyvinyl chloride, polyvinylidene fluoride, polytetrafluoroethylene, or surface-modified metals to ensure that the hydrocarbon oil feedstock forms a thin liquid film on the surface of the packing material, thereby improving the hydrogen dissolution efficiency.

[0044] Hydrogen-saturated hydrocarbon oil gathers into a liquid phase at the bottom of the hydrogen mixing tank, then exits from the bottom outlet and enters the first reactor. The pressure detection device controls the pressure at the top of the hydrogen mixing tank via a control system interlocked with a flow regulating valve on the hydrogen inlet pipeline. The liquid level detection device controls the liquid level at the bottom of the hydrogen mixing tank via a control system interlocked with a flow regulating valve at the top outlet of the first reactor. The liquid level in the hydrogen mixing tank is maintained within the desired range. Preferably, the liquid level in the hydrogen mixing tank is 0.05 to 0.2 times the diameter of the mixing tank. Simultaneously, to entrain small bubbles generated during hydrogen dissolution into the subsequent liquid-phase bed reactor, the apparent flow velocity of the liquid phase in the hydrogen mixing tank is greater than 0.05 m / s.

[0045] In a preferred embodiment of the apparatus provided by this invention, the first reactor contains two or more catalyst beds, with an intermediate gas distributor positioned between adjacent catalyst beds. The intermediate gas distributor is connected to an intermediate hydrogen feed line, through which hydrogen is supplied to the first reactor. The reactants enter the first reactor from the bottom, flow upwards through multiple catalyst beds, and react with the catalyst. In the first reactor, hydrocarbon oil is the continuous phase, and hydrogen exists in dissolved or bubble form.

[0046] An intermediate gas distributor is used to enhance the dissolution and absorption of hydrogen in hydrocarbon oil by highly dispersing hydrogen gas. In addition, a supplementary hydrogen pipeline is used to replenish some new hydrogen in the liquid phase reaction section, thereby improving the reaction efficiency of the liquid phase hydrogenation section.

[0047] In a preferred embodiment, the intermediate gas distributor is a shell-and-tube multi-channel gas distributor, as shown in the attached figure. Figure 2 As shown, the top and bottom of the cylindrical shell are closed, and multiple micro-nanotubes are uniformly arranged axially inside. These micro-nanotubes open on the top and bottom surfaces of the cylindrical shell, allowing communication between the upper and lower catalyst beds. The average pore size of the micro-nanotubes is <10 micrometers. Preferably, the micro-nanoporous tubes are uniformly arranged in a square or equilateral triangle pattern on the cross-section of the intermediate gas distributor, with the total tube area accounting for 30%-80% of the reactor's cross-sectional area. Hydrogen gas passes through the pores in the micro-nanotube walls from the shell side and is dispersed into numerous small bubbles. These bubbles mix and dissolve with the hydrocarbon feedstock within the tube side and then enter the next catalyst bed to replenish the hydrogen consumed in the reaction.

[0048] After the reaction, the material is discharged from the top outlet of the first reactor and enters the second reactor through the top inlet and a liquid distributor. A supplementary hydrogen gas is introduced at the top of the second reactor via a supplementary hydrogen inlet pipeline to adjust the hydrogen-to-oil volume ratio within the second reactor. The second reactor contains one or more catalyst beds. The reactants flow downwards through the catalyst bed, contacting the catalyst for further hydrogenation. In the second reactor, hydrogen is a continuous phase, while hydrocarbon oil exists in the form of droplets and liquid films.

[0049] The first reactor contains different catalyst beds filled with the same or different hydrogenation catalysts, such as hydrogenation protectants and / or hydrogenation catalysts. The second reactor may contain the same or different hydrogenation catalysts as the first reactor; this invention does not limit this.

[0050] Preferably, the hydrogenation catalyst is selected from one or more of the following: hydrogenation refining, pre-hydrogenation refining, selective hydrogenation, hydrogenation treatment, and hydrocracking catalysts. The active components of the catalyst include, but are not limited to, one or more of the following: Co, Mo, Ni, W, Zn, rare earth elements, etc.

[0051] The reactants discharged from the second reactor outlet enter a gas-liquid separation device. This device can be a single gas-liquid separator or multiple gas-liquid separators connected in series. The separated gas is led out through a gas phase outlet for further processing, preferably returned to the reaction unit for recycling. The separated liquid phase is led out through a liquid phase outlet to obtain hydrogenated hydrocarbon oil products, preferably sent to subsequent units for separation and purification.

[0052] In the method provided by this invention, the hydrotreating operating conditions are: reaction temperature 150℃~500℃, pressure 1.0~25MPa, and total volume hourly space velocity (VHSV) of hydrocarbon oil 0.1~20h. -1 The total hydrogen-to-oil volume ratio is 50-600, and the total chemical reaction hydrogen consumption is 0.2wt%-5wt%. The chemical reaction hydrogen consumption refers to the mass of hydrogen consumed per unit mass of feed due to chemical reactions such as olefin saturation, desulfurization, denitrification, deoxygenation, and demetallization.

[0053] The operating conditions of the first reactor and the second reactor can be the same or different. By controlling the reaction conditions, 60% to 95% of the total reaction conversion can be completed in the first reactor, and 5% to 40% of the total conversion reaction can be completed in the second reactor.

[0054] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described in the drawings are for illustration and explanation only and do not limit the present invention.

[0055] Appendix Figure 1 This is a schematic diagram of the hydrogenation treatment apparatus provided by the present invention, as shown below. Figure 1 As shown, the hydrogenation treatment unit includes a hydrogen mixing tank 8, a first reactor A, a second reactor B, and a gas-liquid separation device 14. The liquid inlet at the top of the hydrogen mixing tank is connected to a spray-type liquid distributor 2, and the gas inlet 4 at the bottom of the hydrogen dissolving tank is connected to the hydrogen mixing tank via a flow regulating valve 7. The bottom outlet of the hydrogen mixing tank is connected to the bottom inlet of the first reactor. The first reactor contains two catalyst beds, and the intermediate hydrogen pipeline 5 is connected to an intermediate gas distributor 10 located between adjacent catalyst beds. The top outlet pipeline of the first reactor and the supplementary hydrogen pipeline 6 are connected to the top inlet of the second reactor, and the bottom outlet of the second reactor is connected to the gas-liquid separation device 14.

[0056] The hydrocarbon feedstock is dispersed into tiny droplets at the top of the hydrogen mixing tank 8 via the feedstock inlet pipeline 1 and a spray-type liquid distributor 2. These droplets contact hydrogen and quickly reach hydrogen saturation. Hydrogen enters the mixing tank via the hydrogen inlet pipeline 4, and its flow rate is controlled by the flow regulating valve 7. The opening of the flow regulating valve 7 is interlocked with the pressure detection signal at the top of the mixing tank. After spraying, the droplets converge at the bottom of the mixing tank to form the main liquid phase. The liquid level at the bottom of the mixing tank is measured by a level detection device, and the detection signal is interlocked with the flow regulating valve 11 on the outlet pipeline at the top of the first reactor via the control system. The liquid level is controlled within the required range by adjusting the valve opening. The hydrogen-saturated hydrocarbon oil enters the first reactor A via pipeline 9, flowing upwards through the catalyst bed as a continuous phase and reacting with the catalyst. Supplemental hydrogen enters between the two catalyst bed sections via the intermediate hydrogen pipeline 5 and the gas distributor 10, where it is dispersed into small bubbles and mixes with the hydrocarbon oil to replenish the consumed hydrogen. The material emanating from the first reactor is mixed with supplemental hydrogen from pipeline 6 and then enters the second reactor B. In the second reactor, the material flows from top to bottom, with hydrogen as the continuous phase and liquid hydrocarbon oil reacting with the catalyst in a drip-flow manner. After the reaction, the material enters the gas-liquid separator 14 via pipeline 13 for gas-liquid separation. The separated gas phase is led out through gas phase outlet pipeline 15 for further processing; the separated liquid product is led out through liquid phase outlet pipeline 16 and sent to subsequent units for further separation and purification.

[0057] Appendix Figure 2 A schematic diagram of a multi-channel micro / nanotube gas distributor is attached. Figure 2 As shown, the top and bottom of the cylindrical shell are closed, and multiple micro-nanotubes are uniformly arranged axially inside. These micro-nanotubes open at the top and bottom surfaces of the cylindrical shell, allowing communication between the upper and lower catalyst beds. The average pore size of the micro-nanotubes is <10 micrometers. The micro-nanoporous tubes are uniformly arranged in an equilateral triangle pattern in the cross-section of the intermediate gas distributor.

[0058] The present invention will be further illustrated by the following examples. However, the present invention is not limited thereto.

[0059] In the examples and comparative examples:

[0060] The hydrogenation catalyst RS-1000 is produced by the Catalyst Division of China Petroleum & Chemical Corporation.

[0061] The diesel fraction was obtained from Sinopec Qingdao Petrochemical Co., Ltd., and its properties are shown in Table 1.

[0062] Comparative Example 1

[0063] Comparative Example 1 illustrates the effectiveness of the traditional trickle bed diesel hydrorefining process.

[0064] The reaction process is as follows: Figure 3 As shown, reactor 3 has a height-to-diameter ratio of 20 and is filled with RS-1000 hydrogenation catalyst. Diesel feedstock mixed with new hydrogen 2 enters reactor 3 from the top, flows downwards after passing through a liquid phase distributor, and contacts the hydrogenation catalyst to undergo a hydrogenation reaction. The reacted material is discharged through product outlet pipeline 10 and enters gas-liquid separator 4 for gas-liquid separation. The separated gas phase effluent 5 is unreacted hydrogen, and the liquid phase effluent 6 is hydrorefined diesel. The reaction operating conditions and product properties are shown in Table 2.

[0065] Comparative Example 2

[0066] Comparative Example 2 illustrates the effect of the diesel liquid-phase hydrorefining process.

[0067] The reaction process is as follows: Figure 4 As shown, reactor 3 has a height-to-diameter ratio of 20 and is filled with RS-1000 hydrogenation catalyst. Diesel fraction 1 and fresh hydrogen 2 are mixed in static mixer 9 and then enter from the bottom of reactor 3, where they contact the hydrogenation catalyst to carry out the hydrogenation reaction. The liquid phase is continuous, and the reacted material is discharged through product outlet 10. It then enters gas-liquid separator 4 for gas-liquid separation. The separated gas phase 5 is unreacted hydrogen, and part of the separated liquid phase 6 is recycled at a recycling ratio of 2, while the other part is collected as product. The reaction operating conditions and product properties are shown in Table 2.

[0068] Comparative Example 3

[0069] Comparative Example 3 employs a series connection of liquid-phase hydrogenation and trickle-bed hydrogenation, essentially operating the reactors described in Comparative Example 2 and Comparative Example 1 in series, with both reactors having a height-to-diameter ratio of 20. Diesel feedstock and fresh hydrogen 2 are mixed via static mixer 9 and then enter from the bottom of reactor 3 in Comparative Example 2, contacting the hydrogenation catalyst for the hydrogenation reaction. There is no liquid-phase circulation in one stage of the reaction. After the reaction, the material is mixed with a certain amount of fresh hydrogen and then enters the trickle-bed reactor in Comparative Example 1. The reaction products enter a gas-liquid separator 4 for gas-liquid separation. The separated gas phase effluent 5 is unreacted hydrogen, and the liquid phase effluent 6 is hydrorefined diesel. The catalyst loading in the liquid-phase reactor and the gas-phase reactor is the same. The reaction operating conditions and product properties are shown in Table 2.

[0070] Example 1

[0071] Example 1 uses the attached Figure 1 The hydrocarbon oil hydrotreating apparatus provided by the present invention, as shown, has a hydrogen mixing tank with a height-to-diameter ratio of 3, a first reactor with a height-to-diameter ratio of 15, an inner diameter ratio of the hydrogen mixing tank to the first reactor of 0.6, and a height-to-diameter ratio of the second reactor of 25. A spray-type liquid distributor is installed at the top of the hydrogen mixing tank, with a spray pressure drop of 0.2 MPa. Diesel feedstock is dispersed into tiny droplets by the spray-type liquid distributor, which contact with hydrogen gas in the hydrogen mixing tank and quickly reaches hydrogen saturation. The liquid then enters the bottom of the first reactor from the bottom of the hydrogen mixing tank, where it reacts with the hydrotreating catalyst as a continuous liquid phase. Intermediate hydrogen supplementation enters from a shell-and-tube intermediate gas distributor 10. The structure of the intermediate gas distributor is as follows... Figure 2 As shown, the tubes are micro / nanoporous tubes made of sintered metal with an average pore size of 5 micrometers. Seven tubes are arranged in a uniform equilateral triangle across the reactor cross-section, and the channel area accounts for 50% of the reactor's cross-sectional area. The raw materials and catalysts used in this example are the same as those in the comparative example. The mass ratio of catalyst loaded in the first reactor to the second reactor is 1:2, and the total reaction space velocity is 1.5 h⁻¹. -1 The reaction conditions and results are shown in Table 2.

[0072] Table 1 Properties of Diesel Feedstock

[0073]

[0074]

[0075] Table 2 Results of diesel hydrorefining reaction

[0076]

[0077] *Inlet temperature refers to the inlet temperature of the reactor; outlet temperature refers to the outlet temperature of the reactor.

Claims

1. A hydrocarbon oil hydrotreating device, characterized in that, The system includes a hydrogen mixing tank, a first reactor, a second reactor, and a gas-liquid separation device. The hydrogen mixing tank has a liquid inlet and a gas inlet. The bottom outlet of the hydrogen mixing tank is connected to the bottom inlet of the first reactor. The first reactor contains two or more catalyst beds, and the intermediate hydrogen pipeline is connected to an intermediate gas distributor located between adjacent catalyst beds. The top outlet of the first reactor and the supplementary hydrogen pipeline are connected to the top inlet of the second reactor. The bottom outlet of the second reactor is connected to the gas-liquid separation device. The second reactor contains a catalyst bed. In the hydrogen mixing tank, the liquid phase inlet is located at the top of the hydrogen mixing tank and is connected to a spray-type liquid distributor located inside the hydrogen mixing tank, and the gas phase inlet is connected to a gas distributor. The intermediate gas distributor is a shell-and-tube structure. Multiple micro- and nano-porous tubes are evenly arranged along the axial direction inside the cylindrical shell. The micro- and nano-porous tubes open on the top and bottom surfaces of the cylindrical shell, so that the upper catalyst bed and the lower catalyst bed are connected through the micro- and nano-porous tubes. A gas inlet is provided on the cylindrical shell.

2. The hydrocarbon oil hydrotreating apparatus according to claim 1, characterized in that, The hydrogen mixing tank is also equipped with a pressure detection device and a liquid level detection device; the signal from the pressure detection device is interlocked with the flow regulating valve on the gas phase inlet pipeline through the control system to regulate the pressure inside the hydrogen mixing tank, and the signal from the liquid level detection device is interlocked with the flow regulating valve on the top outlet pipeline of the first reactor through the control system to regulate the liquid level height inside the hydrogen mixing tank.

3. The hydrocarbon oil hydrotreating apparatus according to claim 1 or 2, characterized in that, The hydrogen mixing tank is filled with an oleophilic filler, which is selected from one or more of polypropylene, polyvinyl chloride, polyvinylidene fluoride, polytetrafluoroethylene and surface-modified metal materials.

4. The hydrocarbon oil hydrotreating apparatus according to claim 1 or 2, characterized in that, The height-to-diameter ratio of the hydrogen mixing tank is 2-5:1, the height-to-diameter ratio of the first reactor is 10-30:1, the inner diameter ratio of the hydrogen mixing tank to the first reactor is 0.2-1.0:1, and the height-to-diameter ratio of the second reactor is 15-40:

1.

5. The hydrocarbon oil hydrotreating apparatus according to claim 1, characterized in that, The average pore size of the micro / nanoporous tube is <10 micrometers.

6. The hydrocarbon oil hydrotreating apparatus according to claim 1 or 5, characterized in that, The micro-nano porous tubes are arranged in a uniform square or equilateral triangle pattern on the cross-section of the intermediate gas distributor, and the total area of ​​the tubes accounts for 30%-80% of the cross-sectional area of ​​the reactor.

7. A method for hydrotreating hydrocarbon oil, using the hydrocarbon oil hydrotreating apparatus according to any one of claims 1-6, wherein hydrogen gas enters a hydrogen mixing tank through a gas phase inlet and hydrocarbon oil feedstock enters through a liquid phase inlet; the hydrocarbon oil feedstock is dispersed into droplets with a diameter of less than 1.0 mm by a spray-type liquid distributor, and the hydrocarbon oil droplets contact the hydrogen gas in the hydrogen mixing tank to reach hydrogen saturation; the hydrogen-saturated hydrocarbon oil gathers at the bottom of the hydrogen mixing tank and enters a first reactor from the bottom, where the hydrocarbon oil, as a continuous phase, contacts the catalyst to undergo a hydrogenation reaction; the first reactor is provided with two or more catalyst beds, and hydrogen gas is sent between two adjacent catalyst beds through an intermediate hydrogen pipeline, and distributed into microbubbles by an intermediate gas distributor to replenish the reaction consumption in the hydrocarbon oil; the hydrocarbon oil discharged from the top outlet of the first reactor mixes with the replenished hydrogen gas and enters a second reactor from the top, wherein... Hydrogen is the continuous phase, and hydrocarbon oil is contacted with the catalyst in a dripping manner to carry out a hydrogenation reaction, resulting in hydrogenated hydrocarbon oil.

8. The method for hydrotreating hydrocarbon oil according to claim 7, characterized in that, The pressure drop across the spray-type liquid distributor is 0.1 MPa to 1.0 MPa.

9. The method for hydrotreating hydrocarbon oil according to claim 7, characterized in that, The hydrogen mixing tank is filled with lipophilic packing material. Hydrocarbon oil forms a thin liquid film on the surface of the lipophilic packing material and comes into contact with hydrogen until the hydrogen is saturated.

10. The method for hydrotreating hydrocarbon oil according to claim 7, characterized in that, The operating conditions for the first and second reactors are as follows: reaction temperature 150℃~500℃, pressure 1.0~25MPa, and total volume hourly space velocity (VHSV) of hydrocarbon oil 0.1~20h. -1 The total hydrogen-to-oil volume ratio is 50-600, and the total hydrogen consumption for chemical reactions is 0.2 wt%-5.0 wt%.

11. The hydrocarbon oil hydrotreating method according to claim 10, wherein the operating conditions of the first reactor and the second reactor are controlled to complete 60% to 95% of the total reaction conversion in the first reactor and 5% to 40% of the total conversion reaction in the second reactor.

12. The method for hydrotreating hydrocarbon oil according to claim 7, characterized in that, In the hydrogen mixing tank, the first reactor, and the second reactor, the flow rate ratio of hydrogen introduced is 0.2~3.0:1.0:1.0~10.

0.

13. The method for hydrotreating hydrocarbon oil according to claim 7, characterized in that, The loading ratio of hydrogenation catalyst in the first reactor and the second reactor is 1:1.5-3.

14. The method for hydrotreating hydrocarbon oil according to claim 7, characterized in that, The hydrocarbon feedstock is selected from one or a mixture of several of jet fuel, diesel oil, VGO and residual oil.

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