Internal circulation hydrogenation reactor for producing hydrogen peroxide by anthraquinone process and hydrogenation method

Abstract

The invention provides an internal circulation hydrogenation reactor for producing hydrogen peroxide by an anthraquinone process and a hydrogenation method, the reactor comprises an outer cylinder and a middle cylinder which are coaxially arranged, and at least one inner cylinder arranged in the middle cylinder, the inner cylinder is filled with catalyst particles, an anthraquinone working solution and hydrogen enter the reactor from the bottom and are subjected to a contact reaction in the inner cylinder, and the anthraquinone working solution and the hydrogen are separated from the inner cylinder. Under the driving of the working solution and hydrogen, the catalyst and the working solution move upwards to the top of the inner cylinder, then move downwards through a gap between the inner cylinder and the middle cylinder, and continue to perform hydrogenation reaction under the condition of supplementing hydrogen, and after reaching the bottom, part of the working solution and the catalyst flow back to the inner cylinder, and part of the working solution moves upwards through a gap between the middle cylinder and the outer cylinder; residual solid particles in the working liquid are precipitated in the ascending process of the liquid and flow back to the bottom of the inner barrel, primary solid-liquid separation is completed, and the separated working liquid is discharged through a liquid outlet in the upper part of the outer barrel, namely the hydrogenated liquid. The reactor provided by the invention adopts an internal circulating fluidized bed form, realizes anthraquinone hydrogenation reaction, is beneficial to uniform mixing of reaction materials and a catalyst, has good mass and heat transfer effects in a system, few side reactions and high product quality, and can well solve the hot spot problem generated in the production process of a fixed bed hydrogenator.

Description

Technical Field

[0001] The invention relates to a hydrogenation reactor, in particular to a reactor for realizing a hydrogenation reaction of anthraquinone to produce hydrogen peroxide through internal circulation, and a corresponding hydrogenation method. Background Art

[0002] Hydrogen peroxide is an important chemical widely used in medicine, environmental protection and other fields. At present, the anthraquinone method is widely used to produce hydrogen peroxide at home and abroad. The anthraquinone method for producing hydrogen peroxide uses anthraquinone derivatives as working carriers. Under the action of catalysts, anthraquinone derivatives are hydrogenated to generate hydroanthraquinone, and then oxidized to generate hydrogen peroxide and anthraquinone derivatives. Finally, water is used for extraction to obtain a certain concentration of hydrogen peroxide, and the anthraquinone derivatives are recycled as working fluids. Among them, the efficiency of anthraquinone hydrogenation directly determines the output and concentration of hydrogen peroxide, and is an important link in the production of hydrogen peroxide. At present, fixed bed reactors are often used in the anthraquinone hydrogenation process in China, but fixed bed reactors have problems such as low catalyst utilization, uneven temperature distribution in the bed, severe degradation of the working fluid, and short production cycle. The hydrogen efficiency of anthraquinone hydrogenation in a fixed bed is generally only 6-8g / L. Fluidized bed reactor is an efficient chemical reactor with the advantages of fast reaction speed, uniform reaction, and good heat and mass transfer performance. In the fluidized bed reactor, the working fluid, catalyst and hydrogen can be fully contacted, which increases the anthraquinone conversion rate and solves the problem of uneven bed temperature distribution, which can effectively improve the reaction efficiency and output and reduce production costs. Newly built large-scale hydrogen peroxide production plants abroad generally use fluidized beds for hydrogenation reactions, and the hydrogen efficiency can generally reach more than 12g / L.

[0003] Patent US3423176A discloses a tubular suspended bed reactor for producing hydrogen peroxide by an anthraquinone method. The reactor is composed of horizontal and vertical reaction tubes connected by elbows. A slit channel is formed in the reaction tube. After premixing hydrogen and a material containing a catalyst in a venturi mixer, the slit channel is entered from the bottom of the reaction tube for suspended hydrogenation. The hydrogenation efficiency can reach 12g / L. Patent CN104549059A discloses a slurry bed reactor for producing hydrogen peroxide by an anthraquinone method and its application. A slurry bed reactor with an upper diameter expansion is adopted. The reaction effluent is filtered through a post-filter, the filtrate is discharged, and the catalyst is recycled. The hydrogen efficiency reaches 10g / L. The fluidized bed reactor has a uniform flow state inside, and the catalyst can be fully mixed with the working liquid, reducing the amount of catalyst, and has good mass transfer and heat transfer performance, but the catalyst separation is difficult, and a filtering device needs to be added later, which greatly increases the burden of the filtering equipment.

[0004] The reactor design that realizes online separation of catalysts and maintains good mass and heat transfer performance will greatly reduce the pressure of subsequent filtration, extend the operating cycle, and improve the stability of the reaction. Summary of the invention

[0005] In order to solve the deficiencies in the prior art, the present invention provides an internal circulation hydrogenation reactor and a hydrogenation method for producing hydrogen peroxide by anthraquinone method. Through the design of the reactor, the catalyst can be effectively precipitated and separated in the reactor, which greatly reduces the pressure of the subsequent filtration device and reduces the filtration loss of the catalyst. The reactor can unload and add agents online, and has good mass and heat transfer performance, improves hydrogenation efficiency, and the device can achieve long-term stable operation.

[0006] To achieve the above technical objectives, the first aspect of the present invention provides an internal circulation hydrogenation reactor for producing hydrogen peroxide by an anthraquinone process, comprising an outer cylinder and a middle cylinder arranged coaxially, and at least one inner cylinder arranged in the middle cylinder, the bottoms of the inner cylinder, the middle cylinder and the outer cylinder are connected, the tops of the outer cylinder and the middle cylinder are sealed together, at least one gas-liquid distribution plate is arranged at the bottom of each inner cylinder, the gas-liquid distribution plate is connected to the mixed gas-liquid inlet, the upper end of the inner cylinder extends to the middle or upper part of the middle cylinder, the upper end opening is connected to the inside of the middle cylinder, a plurality of gas distribution plates are arranged at the bottom between the inner cylinder and the middle cylinder, and are connected to the gas inlet; at least one exhaust port is arranged at the top of the middle cylinder and the top between the middle cylinder and the outer cylinder, the top of the middle cylinder is provided with a solid feed port, the bottom between the middle cylinder and the outer cylinder is provided with a solid discharge port, and the upper part of the outer cylinder is provided with a liquid outlet.

[0007] Furthermore, the bottom end of the inner tube is lower than the bottom end of the middle tube.

[0008] Furthermore, the liquid outlet is also connected to a filtering device.

[0009] Furthermore, the ratio of the distance between the bottom end of the inner cylinder and the bottom end of the outer cylinder to the diameter of the inner cylinder is 1:0.3-2.

[0010] Furthermore, the gas distribution plates are symmetrically distributed, or an annular gas distribution plate is provided.

[0011] Furthermore, a baffle with holes is arranged at the upper part of the middle tube and above the reaction zone of the inner tube to prevent the solids in the inner tube from entering the upper outlet. Preferably, the baffle is an inverted V-shaped baffle.

[0012] Furthermore, a baffle is provided at the front end of the liquid outlet, so that the liquid material passes through the baffle and is discharged from the liquid outlet.

[0013] Furthermore, the ratio of the distance from the baffle plate to the inner wall of the outer cylinder to the distance from the outer wall of the middle cylinder to the inner wall of the outer cylinder is 1:1.5-10, and the ratio of the distance from the baffle plate to the inner wall of the outer cylinder to the height of the baffle plate is 1:2-15.

[0014] Furthermore, the bottoms of the middle tube and the inner tube are both provided with outward trumpet-shaped baffles, and the angle between the trumpet-shaped baffles and the horizontal plane is 10°-80°, preferably 25°-70°. The ratio of the length of the inner tube baffle to the distance from the inner wall of the middle tube to the outer wall of the inner tube is 1:1.5-8, preferably 1:2-4, and the ratio of the length of the middle tube baffle to the distance from the inner wall of the outer tube to the inner wall of the middle tube is 1:1.5-8, preferably 1:2-4.

[0015] Furthermore, the ratio of the outer barrel diameter of the hydrogenation reactor to the reactor height is 1:1-30, preferably 1:3-12; the ratio of the cross-sectional area of ​​the outer barrel to the cross-sectional area of ​​the middle barrel is 100:20-90, preferably 100:30-70; the ratio of the cross-sectional area of ​​the middle barrel to the cross-sectional area of ​​the inner barrel is 100:9-64, preferably 100:16-50, and the ratio of the length of the middle barrel to the length of the inner barrel is 100:20-90, preferably 100:30-60.

[0016] The technical purpose of the second aspect of the present invention is to provide a hydrogenation method for producing hydrogen peroxide by anthraquinone method, using the above-mentioned reactor, filling catalyst particles in an inner cylinder, anthraquinone working liquid and hydrogen enter the reactor from the mixed gas-liquid inlet at the bottom, enter the inner cylinder after passing through the gas-liquid distribution plate, the working liquid, hydrogen and catalyst contact and react, driven by the working liquid and hydrogen, the catalyst and working liquid ascend to the top of the inner cylinder, then descend through the gap between the inner cylinder and the middle cylinder, and continue to carry out hydrogenation reaction under the hydrogen supplemented by the gas distribution plate between the middle cylinder and the outer cylinder, after reaching the bottom, part of the working liquid and catalyst flow back to the inner cylinder, part of the working liquid ascends through the gap between the middle cylinder and the outer cylinder, the solid particles remaining in the working liquid precipitate during the liquid ascending process and flow back to the bottom of the inner cylinder, completing the preliminary separation of solid and liquid, and the separated working liquid is discharged through the liquid outlet at the upper part of the outer cylinder, which is the hydrogenated liquid.

[0017] Furthermore, based on the total volume of the middle cylinder, the loading amount of the catalyst particles is 20%-90%, preferably 30%-70%, and most preferably 35%-65%.

[0018] Furthermore, the catalyst used in the above method is a catalyst that can achieve anthraquinone hydrogenation reaction in the prior art, and the average particle size of the particles is 0.01mm-3.0mm, preferably 0.1mm-1.5mm, and most preferably 0.3mm-1.0mm. Specifically, the above catalyst is generally a catalyst with an inorganic refractory oxide as a carrier and a Group VIII metal loaded thereon.

[0019] Furthermore, when the loading amount of catalyst particles is ≥30%, too fine catalysts will be blocked due to the agglomeration effect. Therefore, the average particle size of the catalyst is not less than 0.5 mm. The catalyst in the reactor exists in both fluidized and mobile states. The catalyst forms a moving bed between the inner tube and the middle tube. In this state, the catalyst filling amount is large and the precipitation and separation effect is good. When the loading amount of catalyst particles is not more than 30%, it is easier for the fluid in the reactor to achieve a fluidized state. There are no strict requirements on the average particle size range of the catalyst as above. The reactor is in a fluidized state as a whole, and the mass transfer and heat transfer effects are good. However, the precipitation effect in this way is worse than the former, and the overall reaction is sensitive to pressure and has higher requirements for operation. Considering the overall reaction efficiency, the catalyst particle loading amount is generally kept at a slightly higher level.

[0020] Furthermore, in the above method, the catalyst can be replaced online through the solid feed port at the top and the solid discharge port at the bottom.

[0021] Furthermore, in the above method, the reaction temperature of the inner tube of the reactor is 30-80°C, preferably 40-60°C, and the pressure in the inner tube is 0.15-0.55 MPa, preferably 0.2-0.3 MPa.

[0022] Furthermore, the hydrogenated liquid obtained by the reaction is filtered and then enters the subsequent oxidation unit and extraction separation unit to obtain the product hydrogen peroxide and anthraquinone working solution. It should be understood by those skilled in the art that the hydrogenated liquid needs to be finely filtered multiple times before entering the oxidation unit to ensure that the amount of catalyst residue in the hydrogenated liquid meets the liquid inlet requirements of the oxidation reaction before entering the oxidation unit.

[0023] Furthermore, the anthraquinone working solution is prepared by dissolving alkyl anthraquinone in an organic solvent, and the solvent system disclosed in the prior art can be used, such as anthraquinone derivatives, heavy aromatics (C10), trioctyl phosphate, etc.

[0024] The technical solution of the present invention has the following advantages: (1) The reactor of the present invention adopts the form of an internal circulating fluidized bed to realize the anthraquinone hydrogenation reaction, which is conducive to the uniform mixing of the reaction materials and the catalyst, has good mass and heat transfer effects in the system, has few side reactions, and has high product quality. It can well solve the hot spot problem generated in the production process of the fixed bed hydrogenator.

[0025] (2) The internal circulation hydrogenation reactor of the present invention adopts the method of bottom catalyst separation and upper liquid discharge. The catalyst is precipitated and separated at the bottom of the reactor, and the working liquid is discharged at the top of the reactor. The solid-liquid separation effect is good, which greatly reduces the burden of subsequent filters.

[0026] (3) The internal circulation hydrogenation reactor of the present invention can realize online replacement of the catalyst and extend the operation cycle of the device.

[0027] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the internal circulation hydrogenation reactor device of the present invention; Figure 2 It is a schematic diagram of the flow state of the catalyst and the liquid in the internal circulation hydrogenation reactor when the catalyst loading amount is high; Figure 3 Schematic diagram of the catalyst and liquid flow state when the catalyst loading amount in the internal circulation hydrogenation reactor is high. DETAILED DESCRIPTION

[0029] The following non-limiting embodiments may enable a person skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way. Example 1

[0030] This embodiment provides an internal circulation hydrogenation reactor for producing hydrogen peroxide by anthraquinone process, such as Figure 1 As shown, it includes an outer cylinder 3 and a middle cylinder 2 and an inner cylinder 1 which are coaxially arranged. The bottoms of the inner cylinder 1, the middle cylinder 2 and the outer cylinder 3 are connected. The tops of the outer cylinder 3 and the middle cylinder 2 are sealed together. The bottom of the inner cylinder 1 is lower than the bottom of the middle cylinder 2. A gas-liquid distribution plate 4 is arranged at the bottom of the inner cylinder 1. The gas-liquid distribution plate 4 is connected to the mixed gas-liquid inlet 301 opened on the outer cylinder 3. The upper end of the inner cylinder 1 extends to the middle and upper part of the middle cylinder 2. The upper end opening is connected to the inside of the middle cylinder 2. An inverted V-shaped baffle 5 with an opening is arranged on the upper part of the middle cylinder 2 and above the reaction zone of the inner cylinder 1. The bottom between the inner cylinder 1 and the middle cylinder 2 is arranged Gas distribution plate I6 and gas distribution plate II7 are connected with the air inlet; an exhaust port I201 is arranged at the top of the middle cylinder 2, an exhaust port II302 is arranged at the top between the middle cylinder 2 and the outer cylinder 3, a solid feed port 202 is also arranged at the top of the middle cylinder 2, a solid discharge port I331 and a solid discharge port II332 are arranged at the bottom between the middle cylinder 2 and the outer cylinder 3, a liquid outlet I311 and a liquid outlet II312 are symmetrically arranged at the upper part of the outer cylinder, a baffle I341 and a baffle II342 are arranged at the front end thereof, and a filter I321 and a filter II322 are connected at the rear end thereof. The bottoms of the middle tube 2 and the inner tube 1 are both provided with outward trumpet-shaped baffles. The angle between the trumpet-shaped baffle of the inner tube 1 and the horizontal plane is 45°, and the ratio of the baffle length to the distance from the inner wall of the middle tube 2 to the outer wall of the inner tube 1 is 1:2; the angle between the trumpet-shaped baffle of the middle tube 2 and the horizontal plane is 60°, and the ratio of the baffle length to the distance from the inner wall of the outer tube 3 to the inner wall of the middle tube 2 is 1:2.5.

[0031] In the above reactor, the outer cylinder 3 has a diameter of 12 cm and a height of 70 cm. The ratio of the cross-sectional area of ​​the outer cylinder 3 to the cross-sectional area of ​​the middle cylinder 2 is 100:45, the ratio of the cross-sectional area of ​​the middle cylinder 2 to the cross-sectional area of ​​the inner cylinder 1 is 100:25, and the height ratio of the middle cylinder 2 to the inner cylinder 1 is 100:60. The distance between the bottom end of the inner cylinder 1 and the bottom end of the outer cylinder 3 is 2 cm.

[0032] Method for hydrogenating anthraquinone using the above internal circulation hydrogenation reactor: The inner tube 1 is filled with catalyst particles, and the anthraquinone working liquid and hydrogen enter the reactor from the mixed gas-liquid inlet 301 at the bottom, and enter the inner tube 1 after passing through the gas-liquid distribution plate 4. The working liquid, hydrogen and catalyst contact and react. Driven by the working liquid and hydrogen, the catalyst and working liquid ascend to the top of the inner tube 1, and then descend through the gap between the inner tube 1 and the middle tube 2, and descend between the middle tube 2 and the outer tube 3. The hydrogenation reaction continues under the hydrogen supplemented by the gas distribution plate I6 and the gas distribution plate II7. The reacted gas is discharged through the exhaust port I201 and the exhaust port II302. After the reaction liquid reaches the bottom, the hydrogen and working liquid as feed are quickly passed through the exhaust port I201 and the exhaust port II302 because the reaction is in progress. The liquid goes up through the inner cylinder 1, and a low-pressure zone is generated at the bottom of the inner cylinder 1. Then part of the reaction liquid and the catalyst at the bottom flow toward the low-pressure zone and flow back into the inner cylinder 1, thus realizing the circulation of the catalyst and part of the working liquid. The other part of the reaction liquid, under the action of the outlet pressure, goes up through the gap between the middle cylinder 2 and the outer cylinder 3. The catalyst particles remaining in the reaction liquid are precipitated during the upward movement of the liquid and flow back to the bottom of the inner cylinder 1, thus completing the preliminary separation of the solid and the liquid. The separated working liquid is discharged through the outlet baffles Ⅰ341 and the outlet baffles Ⅱ342 at the upper part of the outer cylinder through the liquid outlet Ⅰ311 and the liquid outlet Ⅱ312, respectively, and is preliminarily filtered through the filters Ⅰ321 and Ⅱ322 to obtain the hydrogenated liquid.

[0033] During the above reaction process, the catalyst particles settle and flow back to the bottom of the outer tube 3, and participate in the reaction again driven by the feed. When the catalyst needs to be replaced, the solid discharge port I331 and the solid discharge port II332 are opened to allow the catalyst to flow out at a certain flow rate for online unloading, and online addition is performed through the solid feed port 202 above the middle tube 2.

[0034] The hydrogenated liquid produced by the reaction is filtered at multiple stages and then enters the oxidation reactor of the oxidation unit to react with oxygen to obtain an oxidized liquid containing hydrogen peroxide. The oxidized liquid is extracted and separated in the extraction device to obtain the product hydrogen peroxide and anthraquinone working liquid. The extracted working liquid is dried and purified before being recycled.

[0035] The working solution used in the following examples is: 2-ethylanthraquinone and a solvent are mixed in a volume ratio of 1:1, and the solvent is a heavy aromatic hydrocarbon and tetrabutyl urea, which are mixed in a volume ratio of 3:1.

[0036] The catalyst is a supported catalyst of palladium on alumina, with a palladium loading of 5%. The carrier is spherical alumina with a specific surface area of ​​more than 800m 2 / g. Example 2

[0037] Based on the total volume of the middle cylinder, the loading amount of catalyst particles is 60% (when the loading amount is large), the average particle size of the catalyst is 0.5 mm, and the flow state of the catalyst and liquid in the reactor is shown in the figure. Figure 2 As shown, the catalyst particles exist in the fluidized state and the moving state at the same time, and the catalyst forms a moving bed between the inner cylinder 1 and the middle cylinder 2. In this state, the catalyst filling amount is large and the precipitation separation effect is good.

[0038] The reaction temperature in the hydrogenation reactor is 50°C, the pressure is 0.2Mpa, and the working liquid feed rate is 0.12m 3 / h, the total hydrogen feed is 0.48Nm 3 / h.

[0039] The liquid after the reaction is first filtered through filter I 321 and filter II 322, and backwashing is performed when the filter pressure difference is set to be greater than 0.1Mpa. The hydrogenated liquid after filtration is then subjected to secondary filtration to make its solid content less than 5ppm. The filtered hydrogenated liquid enters the oxidation reactor, the reaction temperature is 50℃, the pressure is 0.2MPa, and the oxidized product enters the extraction tower, at 55℃, the pure water flow rate is 1.2m 3 / h for extraction treatment. After the reaction stabilized, the hydrogen efficiency of the reaction was 13gH2O2 / L.

[0040] The internal circulation hydrogenation reactor has a large internal circulation volume, which can effectively take away the reaction heat. At the same time, the catalyst particles are in a flowing state to avoid the occurrence of hot spots. The entire system is close to a fully mixed state, and the mass transfer and heat transfer effects are good.

[0041] During the above reaction process, the catalyst is replaced at a rate of 50% per year through online unloading and adding. The above reactor can operate at a long-term temperature to achieve continuous production. Example 3

[0042] Based on the total volume of the middle cylinder, the loading amount of catalyst particles is 25% (when the loading amount is small), the average particle size of the catalyst is 0.3 mm, and the flow state of the catalyst and liquid in the reactor is shown in the figure. Figure 3 As shown, the reactor is in a fluidized state as a whole, with good mass transfer and heat transfer effects and better precipitation and separation.

[0043] The reaction temperature in the hydrogenation reactor is 50°C, the pressure is 0.2Mpa, and the working liquid feed rate is 0.12m 3 / h, the total hydrogen feed is 0.48Nm3 / h.

[0044] The liquid after the reaction is first filtered through filter I 321 and filter II 322, and backwashing is performed when the filter pressure difference is set to be greater than 0.1Mpa. The hydrogenated liquid after filtration is then subjected to secondary filtration to make its solid content less than 5ppm. The filtered hydrogenated liquid enters the oxidation reactor, the reaction temperature is 50℃, the pressure is 0.2MPa, and the oxidized product enters the extraction tower, at 55℃, the pure water flow rate is 1.2m 3 / h for extraction treatment. After the reaction stabilized, the hydrogen efficiency of the reaction was 12gH2O2 / L.

[0045] During the above reaction process, the catalyst is replaced at a rate of 200% per year through online unloading and adding. The above reactor can operate at a long-term temperature to achieve continuous production.

Claims

1. An internal circulation hydrogenation reactor for producing hydrogen peroxide by anthraquinone process, characterized in that: It comprises an outer cylinder and a middle cylinder which are coaxially arranged, and at least one inner cylinder which is arranged in the middle cylinder. The bottoms of the inner cylinder, the middle cylinder and the outer cylinder are communicated with each other, and the tops of the outer cylinder and the middle cylinder are sealed together. At least one gas-liquid distribution plate is arranged at the bottom of each inner cylinder, and the gas-liquid distribution plate is connected with the mixed gas-liquid inlet. The upper end of the inner cylinder extends to the middle or upper part of the middle cylinder, and the upper end opening is communicated with the inside of the middle cylinder. A plurality of gas distribution plates are arranged at the bottom between the inner cylinder and the middle cylinder, and are connected with the gas inlet. At least one exhaust port is arranged at the top of the middle cylinder and at the top between the middle cylinder and the outer cylinder, a solid feed port is arranged at the top of the middle cylinder, a solid discharge port is arranged at the bottom between the middle cylinder and the outer cylinder, and a liquid outlet is arranged at the upper part of the outer cylinder.

2. The internal circulation hydrogenation reactor according to claim 1, characterized in that: The bottom end of the inner tube is lower than the bottom end of the middle tube.

3. The internal circulation hydrogenation reactor according to claim 1, characterized in that: The ratio of the height difference between the bottom end of the inner cylinder and the bottom end of the outer cylinder to the diameter of the inner cylinder is 1:0.3-2.

4. The internal circulation hydrogenation reactor according to claim 1, characterized in that: A baffle with holes is arranged at the upper part of the middle cylinder and above the reaction zone of the inner cylinder to prevent the solid in the inner cylinder from entering the upper outlet.

5. The internal circulation hydrogenation reactor according to claim 1, characterized in that: The bottoms of the middle tube and the inner tube are both provided with outward trumpet-shaped baffles, the angle between the trumpet-shaped baffles and the horizontal plane is 10°-80°, the ratio of the length of the inner tube baffle to the distance from the inner wall of the middle tube to the outer wall of the inner tube is 1:1.5-8, and the ratio of the length of the middle tube baffle to the distance from the inner wall of the outer tube to the inner wall of the middle tube is 1:1.5-8.

6. The internal circulation hydrogenation reactor according to claim 1, characterized in that: The ratio of the outer barrel diameter of the hydrogenation reactor to the reactor height is 1:1-30, the ratio of the cross-sectional area of ​​the outer barrel to the cross-sectional area of ​​the middle barrel is 100:20-90, the ratio of the cross-sectional area of ​​the middle barrel to the cross-sectional area of ​​the inner barrel is 100:9-64, and the ratio of the length of the middle barrel to the length of the inner barrel is 100:20-90.

7. The internal circulation hydrogenation reactor according to claim 1, characterized in that: A baffle plate is also arranged at the front end of the liquid outlet, so that the liquid material can be discharged from the liquid outlet after passing through the baffle plate.

8. The internal circulation hydrogenation reactor according to claim 7, characterized in that: The ratio of the distance from the baffle plate to the inner wall of the outer cylinder to the distance from the outer wall of the middle cylinder to the inner wall of the outer cylinder is 1:1.5-10, and the ratio of the distance from the baffle plate to the inner wall of the outer cylinder to the height of the baffle plate is 1:2-15.

9. A hydrogenation method for producing hydrogen peroxide by anthraquinone method, using the internal circulation hydrogenation reactor according to any one of claims 1 to 8, filling the inner cylinder with catalyst particles, anthraquinone working liquid and hydrogen enter the reactor from the mixed gas-liquid inlet at the bottom, and enter the inner cylinder after passing through the gas-liquid distribution plate, the working liquid, hydrogen and catalyst contact and react, driven by the working liquid and hydrogen, the catalyst and working liquid ascend to the top of the inner cylinder, then descend through the gap between the inner cylinder and the middle cylinder, and continue to undergo hydrogenation reaction under the hydrogen supplemented by the gas distribution plate between the middle cylinder and the outer cylinder, after reaching the bottom, part of the working liquid and catalyst reflux into the inner cylinder, part of the working liquid ascends through the gap between the middle cylinder and the outer cylinder, the solid particles remaining in the working liquid precipitate during the liquid ascending process and reflux to the bottom of the inner cylinder, completing the preliminary separation of solid and liquid, and the separated working liquid is discharged through the liquid outlet at the upper part of the outer cylinder, i.e., hydrogenated liquid.

10. The hydrogenation method according to claim 9, characterized in that The loading amount of the catalyst particles is 20%-90% based on the total volume of the middle cylinder.

11. The hydrogenation method according to claim 9, characterized in that The average particle size of the catalyst particles is 0.01 mm-3.0 mm.

12. The hydrogenation method according to claim 11, characterized in that When the loading amount of catalyst particles is ≥30%, the average particle size of the catalyst shall not be less than 0.5 mm.

13. The hydrogenation method according to claim 9, characterized in that The reaction temperature of the inner tube of the reactor is 30-80°C, and the pressure inside the inner tube is 0.15-0.55Mpa.

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