Systems and methods for producing hydrogen peroxide

Abstract

This invention relates to the field of hydrogen peroxide technology and discloses a system and method for preparing hydrogen peroxide. The system includes a hydrogenation unit, an oxidation unit, and an extraction unit connected in sequence. The hydrogenation unit includes a fixed-bed reactor, comprising: a reactor body; a liquid phase inlet, N gas phase inlets, a liquid phase outlet, and a gas phase outlet arranged sequentially from bottom to top on the reactor body; and N catalyst bed sections and a gas-liquid separation component arranged sequentially from bottom to top within the reactor body; N is a natural number and N≥2; a gas distributor is provided below each catalyst bed section and is connected to the gas phase inlet; the gas-liquid separation component is divided into a two-phase zone, a liquid phase zone, and a gas phase zone; the liquid phase zone has a liquid phase outlet; and the gas phase zone has a gas phase outlet. Using this system to prepare hydrogen peroxide can significantly improve hydrogenation efficiency and hydrogenation selectivity, has good safety, effectively improves the selectivity of the hydrogenation reaction and the efficiency of the device, and extends the service life of the catalyst.

Description

Technical Field

[0001] This invention relates to the field of hydrogen peroxide technology, and more specifically to systems and methods for preparing hydrogen peroxide. Background Technology

[0002] Hydrogen peroxide, also known as hydrogen peroxide solution, is a green chemical product. Its production and use process is almost pollution-free, hence it is called a "clean" chemical product. As an oxidant, bleaching agent, disinfectant, deoxidizer, polymer initiator, and crosslinking agent, it is widely used in industries such as chemical, papermaking, environmental protection, electronics, food, pharmaceutical, textile, mining, and agricultural waste processing.

[0003] The anthraquinone process is the mainstream method for industrial hydrogen peroxide production, accounting for over 99% of global industrial hydrogen peroxide production by output. The anthraquinone process includes steps such as hydrogenation, oxidation, extraction, and post-treatment of the circulating working fluid. The efficiency of anthraquinone hydrogenation directly affects the efficiency of the entire production unit and the product concentration. The "hydrogen efficiency" is commonly used to characterize anthraquinone hydrogenation efficiency, which is the number of grams of hydrogen peroxide per liter of hydrogenation reaction liquid (called the "hydrogenation liquid"). Domestic hydrogen peroxide production technology uses a trickle bed hydrogenation process, which generally has a hydrogen efficiency of only 6-7 g / L, resulting in low unit production efficiency. The main reason for this is that in the trickle bed reactor, hydrogen gas is the continuous phase, and the reaction liquid (called the "working liquid") is the dispersed phase, making it easy for flow deviation or channeling to occur within the bed. This leads to localized over-hydrogenation and hot spots within the bed, and also results in a high temperature rise within the bed, leading to the following shortcomings:

[0004] (1) The catalyst is prone to deactivation and must be regenerated or replaced regularly, which not only consumes steam but also causes the loss of working fluid and precious metals in the catalyst. Currently, in the fixed-bed hydrogenation process in China, the catalyst needs to be regenerated with steam every 3-6 months.

[0005] (2) To prevent over-hydrogenation, the anthraquinone conversion rate is usually controlled at a relatively low level (30-40%), which limits hydrogen efficiency and results in low unit efficiency. Compared with a unit of the same scale with high hydrogen efficiency, the circulating working fluid volume is larger, and the power consumption of pumps is greater.

[0006] (3) The working fluid is easily degraded. In industry, a large amount of activated alumina is used to continuously regenerate the circulating working fluid. The activated alumina needs to be replaced frequently, generating a large amount of solid hazardous waste and causing loss of working fluid. For example, producing 1 ton of hydrogen peroxide product requires 5 kg of activated alumina, which will result in a loss of 3 kg of working fluid.

[0007] (4) The equipment has poor safety, requiring the use of a potassium carbonate drying tower to remove saturated water from the circulating working fluid and enhance working fluid regeneration. Hydrogen peroxide decomposes upon contact with alkali, posing a serious safety hazard. Safety accidents occur annually with the hydrogen peroxide unit, with 80% of these accidents caused by alkali contamination in the system to the oxidation and extraction units.

[0008] CN104843648A discloses a fixed-bed hydrogenation reaction system for producing hydrogen peroxide using the anthraquinone process. The hydrogenation tower has a nozzle at the top as a working liquid inlet, and hydrogen gas also enters from the top of the reactor via a distributor. To improve the uniformity of gas-liquid distribution within the reactor and reduce the temperature rise of the reactor bed, the hydrogenation reaction system provided in the patent incorporates a heat exchanger layer and a gas-liquid distributor between the catalyst layers. The reactor structure provided in the patent is complex, increasing the reactor height, and there is a risk of leakage from the internal heat exchanger leading to catalyst deactivation.

[0009] CN1108984C discloses a method for regenerating a working solution, in which at least a portion of the unreduced working solution is contacted with a catalyst mainly containing γ-alumina at 40-150°C to regenerate byproducts in the working solution. However, placing the working solution regeneration before hydrogenation (the "unreduced" stage) and contacting the working solution with the γ-alumina catalyst at 40-150°C, while regenerating hydrogenation byproducts, can also lead to secondary side reactions. These byproducts entering the anthraquinone hydrogenation reactor could potentially affect the activity of the hydrogenation catalyst.

[0010] CN204237558U discloses a post-processing device for the anthraquinone process of hydrogen peroxide production, which includes an alkali tower and a vacuum dryer. CN1334235A discloses a post-processing technology for the anthraquinone process of hydrogen peroxide production, which uses quantitative alkali injection to neutralize the acidity of the working solution returned to hydrogenation, ensuring the alkalinity required for hydrogenation, and simultaneously decomposing some of the hydrogen peroxide in the working solution; then, the solution is dried under vacuum to remove moisture.

[0011] Both of the above post-treatment technologies require the introduction of alkaline solution into the system, which is unsafe and poses serious safety hazards. Summary of the Invention

[0012] The purpose of this invention is to overcome the problems in existing hydrogen peroxide preparation processes, such as low device efficiency and poor safety, low hydrogenation efficiency and poor selectivity, and easy catalyst deactivation caused by local over-hydrogenation and local hot spots in the reactor bed.

[0013] To achieve the above objectives, a first aspect of the present invention provides a system for preparing hydrogen peroxide, the system comprising a hydrogenation unit, an oxidation unit, and an extraction unit connected in sequence; wherein:

[0014] The hydrogenation unit is used to sequentially hydrogenate and separate hydrogen-containing gas and working fluid to obtain hydrogenated liquid and hydrogen-containing tail gas. The hydrogenated liquid is divided into liquid A and liquid B. The hydrogenation unit includes a hydrogenation reactor, which is a fixed-bed reactor. The hydrogenation reactor includes: a reactor body, a liquid phase inlet, N gas phase inlets, a liquid phase outlet, and a gas phase outlet arranged sequentially from bottom to top on the reactor body, and N catalyst bed layers and a gas-liquid separation component arranged sequentially from bottom to top within the reactor body; wherein N is a natural number and N≥2.

[0015] A gas distributor is provided below each section of the catalyst bed, and the gas distributor is connected to the gas inlet.

[0016] The gas-liquid separation component is divided into a two-phase region, a liquid phase region, and a gas phase region; the liquid phase region is provided with a liquid phase outlet; and the gas phase region is provided with a gas phase outlet.

[0017] The hydrogenation unit further includes a regeneration reactor, which is connected to the liquid phase outlet of the hydrogenation reactor and the inlet of the oxidation unit, and is used to regenerate liquid A to obtain regenerated hydrogenated liquid.

[0018] The oxidation unit is used to oxidize the B liquid, the regenerated hydrogenated liquid, and the oxygen-containing gas to obtain an oxidized liquid.

[0019] The extraction unit is used to extract the oxidizing liquid to obtain a hydrogen peroxide solution and a raffinate, and the raffinate is returned to the hydrogenation unit.

[0020] A second aspect of the present invention provides a method for preparing hydrogen peroxide, the method being carried out in the system described in the first aspect; wherein the method includes the following steps:

[0021] (1) In the presence of a hydrogenation catalyst, hydrogen-containing gas enters the reactor cylinder through N gas phase inlets, and is then dispersed into hydrogen-containing gas bubbles by N gas distributors. After contacting with the working liquid that enters the reactor cylinder through the liquid phase inlet, hydrogenation reactions are carried out independently in N catalyst bed sections. The resulting reaction products flow upward into the gas-liquid separation unit for gas-liquid separation to obtain hydrogenated liquid and hydrogen-containing tail gas. The hydrogenated liquid flows out through the liquid phase outlet. The catalyst bed is filled with the hydrogenation catalyst.

[0022] (2) The hydrogenated liquid is divided into liquid A and liquid B; liquid A is regenerated in the presence of a regeneration catalyst to obtain a regenerated hydrogenated liquid;

[0023] (3) The B liquid, the regenerated hydrogenated liquid and the oxygen-containing gas are subjected to an oxidation reaction to obtain an oxidized liquid;

[0024] (4) Extract the oxidizing solution to obtain a hydrogen peroxide solution and a raffinate, and return the raffinate to the working solution;

[0025] The mass flow rate ratio of liquid A to liquid B is 10-25:75-90.

[0026] The system and method provided by the present invention, through the above technical solutions, have the following characteristics and advantages:

[0027] (1) In the system provided by the present invention, the hydrogenation unit uses a specific fixed-bed reactor, which is a gas-liquid co-flow upflow reactor. The catalyst in the N-section (N is a natural number and N≥2) catalyst bed is immersed in the liquid phase. The gas distributor set under each section of the catalyst bed can disperse the gas phase into tiny bubbles, so that the gas and liquid phases can be uniformly contacted in the catalyst bed, enhance gas-liquid mass transfer, improve the utilization rate of the catalyst bed, basically eliminate channeling and bias flow in the bed, as well as the resulting local over-hydrogenation and local hot spots.

[0028] (2) The hydrogenation reactor used in this invention is equipped with N catalyst bed layers. Each catalyst bed layer is equipped with a gas distributor below it. The gas phase enters the reactor cylinder in multiple streams according to the number of catalyst bed layers. This can prevent the already formed micro bubbles from accumulating in the catalyst and reduce the gas-liquid mass transfer effect. In particular, from bottom to top, the second to the Nth catalyst bed layers are equipped with a circulating liquid phase inlet below each catalyst bed layer to remove the heat of reaction and reduce the temperature rise of the bed layer.

[0029] (3) The hydrogenation reactor used in this invention integrates multiple functions such as reaction, gas-liquid mass transfer, gas-liquid separation, and heat extraction. It has a simple and compact structure, is easy to operate, occupies a small area, reduces material consumption, energy consumption and production costs, and improves the inherent safety of the device.

[0030] (4) The hydrogenation reactor used in this invention has superior performance in terms of mass transfer and heat transfer, and can be used for hydrogenation reactions, especially for the hydrogenation reaction of anthraquinone process to prepare hydrogen peroxide. The system provided by this invention can improve the selectivity, hydrogen efficiency and device efficiency of the hydrogenation reaction, especially the hydrogen efficiency can be improved to 8-10 g / L, reduce the amount of circulating working fluid, reduce energy consumption; extend the life of the hydrogenation catalyst, reduce the consumption caused by catalyst regeneration; reduce the amount of regenerated working fluid, reduce the consumption caused by working fluid regeneration and the amount of solid waste generated; eliminate the need for working fluid regeneration in the alkali tower, and improve the intrinsic safety of the device.

[0031] (5) The method provided by the present invention first performs a hydrogenation reaction and then regenerates liquid A, which can avoid catalyst deactivation caused by the regenerated catalyst dust entering the reactor and adhering to the surface of the hydrogenation catalyst. In addition, it can also prevent secondary byproducts from reducing the activity of the hydrogenation catalyst, extend the life of the hydrogenation catalyst, and reduce the cost loss caused by the regeneration of deactivated catalyst.

[0032] (6) The present invention can ensure the regeneration effect of the working fluid by passing the hydrogenated liquid (A liquid) with a mass flow rate of 10-25% through the regeneration reactor. While ensuring the high hydrogen efficiency of the device, it also reduces the amount of regeneration catalyst used for regeneration of the working fluid with a mass flow rate of 70-80%, greatly reduces the generation of solid waste, and significantly improves the economic efficiency and environmental protection of the device.

[0033] (7) The method provided by the present invention can completely eliminate the alkali tower, adopt vacuum drying, and provide a fully acidic environment for the device. While ensuring the stability of the fixed bed hydrogenation reaction, it eliminates the serious safety hazards caused by the cross-contamination of alkali in the system and greatly improves the inherent safety of the hydrogen peroxide production device. In particular, it can effectively utilize the stripping liquid, water and / or organic matter obtained by vacuum drying at least part of the raffinate, which is both effective and environmentally friendly. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of a system for preparing hydrogen peroxide according to a specific embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of the structure of the hydrogenation reactor in a specific embodiment of the present invention.

[0036] Explanation of reference numerals in the attached figures

[0037] I. Hydrogenation reactor; II. Compressor; III. First cooler; IV. Gas flow controller

[0038] V. Liquid flow controller; VI. Pressure controller; VII. Liquid level controller

[0039] VIII, Oxidation Reactor IX, Extraction Tower X, Gas Flow Control Valve XI, Liquid Flow Control Valve

[0040] XII, Pressure regulating valve; XIII, Liquid level regulating valve

[0041] 1. Reactor shell 2. Liquid phase inlet 3. Gas phase inlet 4. Gas phase outlet

[0042] 5. Liquid phase outlet; 6. Catalyst bed; 7. Gas distributor; 8. Separation component cylinder.

[0043] 9. Baffle plate; 10. Overflow pipe; 11. Anti-surge baffle; 12. Circulating liquid phase inlet.

[0044] 13. Liquid distributor; 14. Regeneration reactor; 15. Heat exchanger; 16. Heater.

[0045] 17. Secondary cooler; 18. Precision filter; 19. Tertiary cooler; 20. Vacuum drying tower.

[0046] 01. Hydrogen-containing gas; 02. Working fluid; 03. Hydrogenated liquid; 04. Hydrogen-containing exhaust gas.

[0047] 05. Pressurized hydrogen-containing exhaust gas; 06. Partial hydrogenated liquid; 07. Cooling hydrogenated liquid; 08. Oxidizing liquid.

[0048] 09. Hydrogen peroxide solution; 010. Raffinate; 011. Regenerated hydrogenated solution; 012. Oxygen-containing gas.

[0049] 013. Circulating working fluid; 014. Water and / or organic matter; 015. First pH adjuster; 016. Oxygen-containing exhaust gas.

[0050] 017. Extractant Detailed Implementation

[0051] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0052] In this invention, unless otherwise specified, hydrogen efficiency, or hydrogenation efficiency, refers to the amount of hydrogen peroxide, expressed in g / L. That is, if the yield of the oxidation step in the oxidation reactor is 100%, the amount of hydrogen peroxide (g) that 1 L of working solution can provide when the oxidation step is completed.

[0053] In this invention, unless otherwise specified, the top of the tower body refers to the position of 0-10% of the tower body from top to bottom; the upper part of the tower body refers to the position of 10-40% of the tower body from top to bottom; the middle part of the tower body refers to the position of 40-60% of the tower body from top to bottom; the lower part of the tower body refers to the position of 60-90% of the tower body from top to bottom; and the bottom of the tower body refers to the position of 90-100% of the tower body from top to bottom.

[0054] In this invention, unless otherwise specified, "first," "second," and "Nth" do not indicate a sequence or limit the various materials or steps; they are merely used to distinguish or indicate that these are not the same material or step. For example, in "first contact," "second contact," and "Nth contact," "first," "second," and "Nth" are only used to indicate that these are not the same contact.

[0055] In this invention, unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0056] The first aspect of this invention provides a system for preparing hydrogen peroxide, the system comprising a hydrogenation unit, an oxidation unit, and an extraction unit connected in sequence; wherein:

[0057] The hydrogenation unit is used to sequentially perform hydrogenation reaction and gas-liquid separation on hydrogen-containing gas and working fluid to obtain hydrogenated liquid and hydrogen-containing tail gas. The hydrogenated liquid is divided into liquid A and liquid B.

[0058] The hydrogenation unit includes a hydrogenation reactor, which is a fixed-bed reactor. The hydrogenation reactor includes: a reactor body, a liquid phase inlet, N gas phase inlets, a liquid phase outlet and a gas phase outlet arranged sequentially from bottom to top on the reactor body, and N catalyst bed layers and a gas-liquid separation component arranged sequentially from bottom to top in the reactor body; wherein, N is a natural number and N≥2.

[0059] A gas distributor is provided below each section of the catalyst bed, and the gas distributor is connected to the gas inlet.

[0060] The gas-liquid separation component is divided into a two-phase region, a liquid phase region, and a gas phase region; the liquid phase region is provided with a liquid phase outlet; and the gas phase region is provided with a gas phase outlet.

[0061] The hydrogenation unit further includes a regeneration reactor, which is connected to the liquid phase outlet of the hydrogenation reactor and the inlet of the oxidation unit, and is used to regenerate liquid A to obtain regenerated hydrogenated liquid.

[0062] The oxidation unit is used to oxidize the B liquid, the regenerated hydrogenated liquid, and the oxygen-containing gas to obtain an oxidized liquid.

[0063] The extraction unit is used to extract the oxidizing liquid to obtain a hydrogen peroxide solution and a raffinate, and the raffinate is returned to the hydrogenation unit.

[0064] In existing anthraquinone process systems for hydrogen peroxide production, fixed-bed reactors and / or slurry-bed reactors are commonly used as hydrogenation reactors. Slurry-bed reactors, with their advantages of uniform gas-liquid-solid three-phase contact and consistent bed temperature, have become the trend in anthraquinone hydrogen peroxide production. Fixed-bed reactors, however, suffer from poor gas-liquid distribution leading to insufficient catalyst activity and localized hot spots resulting in excessive degradation products, thus limiting their use. During their research, the inventors of this invention discovered that the system provided by this invention uses a specific fixed-bed reactor as the hydrogenation reactor. This reactor comprises: a reactor body; a liquid phase inlet, N gas phase inlets, a liquid phase outlet, and a gas phase outlet arranged sequentially from bottom to top on the reactor body; and N catalyst bed sections and a gas-liquid separation component arranged sequentially from bottom to top within the reactor body; wherein N is a natural number and N≥2;

[0065] A gas distributor is provided below each section of the catalyst bed, and the gas distributor is connected to the gas inlet.

[0066] The gas-liquid separation component is divided into a two-phase region, a liquid phase region, and a gas phase region; the liquid phase region is provided with a liquid phase outlet; and the gas phase region is provided with a gas phase outlet.

[0067] The device includes a hydrogenation unit in a specific hydrogenation reactor, combined with a specific oxidation unit and an extraction unit. Hydrogen-containing gas and working fluid are sequentially subjected to hydrogenation reaction and gas-liquid separation to obtain hydrogenated liquid and hydrogen-containing tail gas. The hydrogenated liquid is divided into liquid A and liquid B. Liquid A is regenerated, and the resulting regenerated hydrogenated liquid, liquid B, and oxygen-containing gas are then oxidized. The reaction products are extracted to prepare hydrogen peroxide. This method can improve the selectivity, hydrogen efficiency, and device efficiency of the hydrogenation reaction, especially increasing the hydrogen efficiency to 7-10 g / L, reducing the amount of circulating working fluid, and extending the lifespan of the hydrogenation catalyst.

[0068] In this invention, unless otherwise specified, the number of specific components in the hydrogenation reactor is one, except for components with a clearly defined number; for example, the number of liquid phase inlet is one; similarly, the number of gas-liquid separation components is also one.

[0069] In this invention, unless otherwise specified, the liquid phase inlet, N gas phase inlets, liquid phase outlet and gas phase outlet arranged sequentially on the reactor cylinder from bottom to top refer to the liquid phase inlet, the first gas phase inlet, the second gas phase inlet, ... the (N-1)th gas phase inlet, the Nth gas phase inlet, the liquid phase outlet and the gas phase outlet being arranged sequentially on the reactor cylinder from bottom to top along the height of the reactor cylinder.

[0070] In this invention, unless otherwise specified, the N-section catalyst bed and gas-liquid separation component arranged sequentially from bottom to top in the reactor cylinder refers to the reactor cylinder having a first catalyst bed, a second catalyst bed, ..., an (N-1)th catalyst bed, an Nth catalyst bed, and a gas-liquid separation component arranged sequentially from bottom to top.

[0071] According to some embodiments of the present invention, the catalyst bed has at least two segments. Preferably, the catalyst bed has 2-8 segments, more preferably 3-5 segments, for example, 3, 4, or 5 segments. Preferably, the catalyst bed is filled with a hydrogenation catalyst. The type of hydrogenation catalyst has a wide range of selection and can be a conventional fixed-bed catalyst, which is not limited by the present invention. For example, it can be a spherical or strip-shaped granular supported catalyst and / or an unsupported catalyst, preferably a supported catalyst. More preferably, the supported catalyst includes a support and an active metal, wherein the active metal is selected from at least one of Group VIII, Group IB, and Group IIB metals, preferably at least one of platinum, rhodium, palladium, cobalt, nickel, ruthenium, copper, and rhenium; the support is selected from at least one of activated carbon, silicon carbide, alumina, silicon oxide, silica, titanium dioxide, zirconium dioxide, magnesium oxide, zinc oxide, calcium carbonate, and barium sulfate, preferably alumina and / or silica.

[0072] In some embodiments of the present invention, preferably, the content of the active metal is 0.01-10 wt%, more preferably 0.01-5 wt%, and more preferably 0.1-2 wt%, based on the total weight of the hydrogenation catalyst.

[0073] In some embodiments of the present invention, preferably, the hydrogenation catalyst has a particle diameter of 0.1-10 mm, more preferably 1-10 mm, and more preferably 2-6 mm.

[0074] According to some embodiments of the present invention, preferably, the height-to-diameter ratio of the catalyst bed is 1:0.5-5, for example, 1:0.5, 1:0.8, 1:1, 1:1.5, 1:2, 1:3, and any value within the range of any two values, preferably 1:0.8-3, to avoid gas flow deviation or bubble aggregation that could affect the reaction effect and selectivity.

[0075] According to some embodiments of the present invention, preferably, the height-to-diameter ratio of the reactor cylinder is 3-30:1, for example, 3:1, 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, and any value within the range of any two values, preferably 5-20:1. Wherein, the height-to-diameter ratio of the reactor cylinder is the ratio of the height of the reactor cylinder to the inner diameter of the reactor cylinder.

[0076] According to some embodiments of the present invention, preferably, the height ratio of each section of the catalyst bed to the reactor cylinder is 1:3-20, for example, 1:3, 1:4, 1:5, 1:8, 1:10, 1:12, 1:15, 1:20, and any value in any range of any two values, preferably 1:4-15.

[0077] According to some embodiments of the present invention, preferably, the height ratio of the gas-liquid separation component to the reactor cylinder is 1:3-30, for example, 1:3, 1:4, 1:5, 1:8, 1:10, 1:12, 1:15, 1:20, 1:25, 1:30, and any value within the range of any two values, preferably 1:4-15.

[0078] In this invention, unless otherwise specified, the number of catalyst bed segments, the number of gas distributors, and the number of gas phase inlets are the same. That is, an N-segment catalyst bed corresponds to N gas distributors and N gas phase inlets, where N is a natural number and N≥2.

[0079] In this invention, in each catalyst bed segment, the gas phase inlet is connected to the gas distributor, and the gas distributor is located below the catalyst bed. Therefore, the gas phase inlet is also located below the catalyst bed. Preferably, the shortest distance d1 between the gas phase inlet and the lower surface of the catalyst bed is 0.1-1.5 m, for example, 0.1, 0.2, 0.3, 0.5, 0.6, 0.8, 1, 1.2, 1.5, and any value within the range of any two values, preferably 0.2-0.8 m.

[0080] According to some embodiments of the present invention, preferably, the gas distributor is selected from perforated tubes or microporous elements; more preferably, the pore size of the perforated tube is 0.5-12 mm, for example, 0.5, 1, 2, 3, 5, 6, 8, 10, 12, and any value within the range of any two values, preferably 1-8 mm; the pore size of the microporous element is 0.2-500 μm, for example, 0.2, 0.5, 1, 10, 20, 30, 50, 60, 80, 100, 120, 150, 180, 200, 300, 400, 500, and any value within the range of any two values, preferably 0.5-200 μm. By dispersing the gas phase into tiny bubbles, the gas and liquid phases are uniformly contacted within the catalyst bed, enhancing gas-liquid mass transfer and improving device efficiency.

[0081] In some embodiments of the present invention, preferably, the microporous element is selected from at least one of sintered membrane tubes, sintered membrane plates, metal sintered mesh tubes, and metal sintered mesh plates.

[0082] In this invention, to further enhance gas-liquid mass transfer and improve device efficiency, preferably, a liquid distributor is disposed below each section of the catalyst bed, and the liquid distributor is disposed below the gas distributor. The type of liquid distributor is not limited, and the liquid distributor includes, but is not limited to, a tubular distributor.

[0083] In a preferred embodiment of the present invention, the liquid distributor can be shared with the gas distributor.

[0084] In some embodiments of the present invention, preferably, the gas-liquid separation component includes a separation component cylinder, and a baffle, an overflow pipe, and an anti-impact baffle disposed within the separation component cylinder; more preferably, the area formed by the overflow pipe and the anti-impact baffle is the two-phase region; the area formed by the baffle and the inner wall of the separator cylinder is the liquid phase region; and the area formed by the anti-impact baffle and the inner wall of the separator cylinder is the gas phase region.

[0085] According to some embodiments of the present invention, preferably, the ratio of the inner diameter of the separation component cylinder and the reactor cylinder is 0.2-1.5:1, for example 0.2:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1.2:1, 1.5:1, and any value within the range of any two values, preferably 0.5-1:1.

[0086] In this invention, unless otherwise specified, when 1:1 < the ratio of the inner diameters of the separating component cylinder and the reactor cylinder ≤ 1.5:1, that is, relative to the straight section of the reactor cylinder, the separating component cylinder is an expanded diameter section; when 0.2:1 ≤ the ratio of the inner diameters of the separating component cylinder and the reactor cylinder < 1:1, that is, relative to the straight section of the reactor cylinder, the separating component cylinder is a reduced diameter section; when the ratio of the inner diameters of the separating component cylinder and the reactor cylinder is 1:1, the separating component cylinder and the reactor cylinder are straight cylinder sections with equal inner diameters.

[0087] In some embodiments of the present invention, preferably, the included angle α between the partition and the separation component cylinder is 45°-90°, and the included angle β between the partition and the overflow pipe is 90°-145°.

[0088] In some embodiments of the present invention, preferably, the inner diameter ratio of the overflow pipe and the separation component cylinder is 0.15-0.75:1, for example, 0.15:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.75:1, or any of any two values ​​within a range, preferably 0.2-0.6:1. This configuration, by adjusting the range of the two-phase region and the liquid phase region, is more conducive to promoting gas-liquid separation and obtaining the hydrogenation reaction product, i.e., the hydrogenated liquid.

[0089] In some embodiments of the present invention, preferably, the height ratio of the overflow pipe to the separation component cylinder is 0.2-0.95:1, for example, 0.2:1, 0.3:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.95:1, or any of any two values ​​within a range, preferably 0.5-0.8:1; this setting, by adjusting the range of the two-phase region and the gas phase region, is more conducive to promoting gas-liquid separation and obtaining hydrogen-containing tail gas.

[0090] In some embodiments of the present invention, preferably, the cross-section of the overflow pipe is a regular shape, preferably selected from at least one of quadrilateral, trapezoid, arc and circle, and preferably circular.

[0091] In some embodiments of the present invention, preferably, the anti-rush baffle is disposed above the overflow pipe; more preferably, the shortest distance between the lower edge of the anti-rush baffle and the upper end of the overflow pipe is 0.3-1.2m, for example, 0.3, 0.5, 0.6, 0.8, 1, 1.2, and any value in the range of any two values, preferably 0.3-0.8m.

[0092] In this invention, the structure of the anti-impact baffle is not limited. Preferably, the anti-impact baffle is a conical structure; more preferably, the anti-impact baffle is a conical structure, with an included angle γ of 110°-145°. This configuration can effectively prevent gas-liquid two-phase splashing in the two-phase region and improve the gas-liquid separation effect.

[0093] According to some embodiments of the present invention, preferably, the liquid phase inlet is located at the bottom of the reactor shell, and the gas phase outlet is located at the top of the reactor shell.

[0094] In some embodiments of the present invention, preferably, a liquid flow controller and a liquid flow regulating valve are provided on the pipe connected to the liquid inlet.

[0095] According to some embodiments of the present invention, preferably, the gas phase outlet is connected to N gas phase inlets; more preferably, a compressor is provided on the pipeline connecting the gas phase outlet and the gas phase inlets.

[0096] According to some embodiments of the present invention, preferably, a gas flow controller is provided on the pipe of each gas phase inlet; more preferably, a gas flow regulating valve is provided on the pipe connecting the gas phase inlet and the gas flow controller, and the gas flow regulating valve is located between the gas phase inlet and the gas flow controller. This arrangement allows for the regulation of the gas-liquid contact within the catalyst bed by adjusting the gas flow rate at each gas phase inlet according to reaction requirements, thereby enhancing liquefaction mass transfer, eliminating channeling and flow deviation within the catalyst bed, and preventing localized over-hydrogenation and localized hot spots.

[0097] According to some embodiments of the present invention, preferably, the hydrogenation reactor further includes (N-1) circulating liquid phase inlets connected to the liquid phase outlet, and each of the circulating liquid phase inlets is independently disposed on the reactor body.

[0098] According to some embodiments of the present invention, preferably, from bottom to top, the second to the Nth segment, each segment of the catalyst bed has its own independently provided circulating liquid phase inlet below it.

[0099] In some embodiments of the present invention, preferably, from bottom to top, the (N-1)th circulating liquid phase inlet is located below the Nth gas phase inlet.

[0100] In some embodiments of the present invention, preferably, the shortest distance d2 between the circulating liquid phase inlet and the bottom of the catalyst bed is 0.2-1.2m, for example, 0.2, 0.3, 0.5, 0.6, 0.8, 1, 1.2, and any value in the range of any two values, preferably 0.3-0.8m.

[0101] In some embodiments of the present invention, preferably, a first cooler is provided on the pipe connecting the circulating liquid phase inlet and the liquid phase outlet to remove the heat of reaction, reduce the temperature rise of the catalyst bed, improve the reaction selectivity, and thus improve the reaction conversion rate and device efficiency.

[0102] In some embodiments of the present invention, to regulate the flow rate of the circulating liquid phase, preferably, a liquid flow controller is also provided on the pipe connecting the circulating liquid phase inlet and the liquid phase outlet, and the liquid flow controller is located before the first cooler.

[0103] In some embodiments of the present invention, preferably, a liquid flow regulating valve is also provided on the pipe connecting the circulating liquid phase inlet and the liquid phase outlet, and the liquid flow regulating valve is located between the liquid flow controller and the circulating cooler.

[0104] In this invention, unless otherwise specified, the liquid flow controller being located before the first cooler means that, in accordance with the direction of circulating liquid flow, the liquid flow controller, the liquid flow regulating valve, and the first cooler are sequentially installed on the pipes at the liquid outlet and the circulating liquid inlet.

[0105] In some embodiments of the present invention, preferably, a pressure controller is provided at the top of the reactor shell; more preferably, a pressure regulating valve is provided on the pipeline connecting the gas phase outlet, the gas phase inlet, and the pressure controller. The pressure regulating valve regulates the connection between the gas phase outlet, the gas phase inlet, and the pressure controller.

[0106] In some embodiments of the present invention, preferably, a level controller is provided in the liquid phase zone, and preferably, a level regulating valve is provided on the pipe connected to the liquid phase outlet. The level regulating valve connects the level controller and the liquid phase outlet.

[0107] In some embodiments of the present invention, preferably, the hydrogenation unit further includes a heat exchanger connected to the liquid phase outlet of the hydrogenation reactor, the inlet of the regeneration reactor, and the regenerated hydrogenated liquid outlet of the regeneration reactor, for exchanging heat between the A liquid and the regenerated hydrogenated liquid.

[0108] In some embodiments of the present invention, preferably, the hydrogenation unit further includes a heater connected to the outlet of liquid A of the heat exchanger and the inlet of the regeneration reactor, for heating the heat exchange liquid (liquid A being exchanged).

[0109] In some embodiments of the present invention, preferably, the hydrogenation unit further includes a second cooler, which is connected to the liquid phase outlet of the hydrogenation reactor, the outlet of the regeneration reactor and the inlet of the oxidation unit, for second cooling of the first stream to obtain a second coolant before entering the oxidation unit, wherein the first stream is the B liquid and the regenerated hydrogenation liquid.

[0110] In some embodiments of the present invention, preferably, the hydrogenation unit further includes a precision filter connected to the second coolant outlet of the second cooler and the inlet of the oxidation unit, for filtering the second coolant.

[0111] In some embodiments of the present invention, the oxidation unit includes an oxidation reactor.

[0112] In some embodiments of the present invention, preferably, the oxidation unit further includes a third cooler, which is connected to the oxidation liquid outlet of the oxidation reactor and the inlet of the extraction unit, for third cooling of the oxidation liquid to obtain a third coolant before entering the extraction unit.

[0113] In some embodiments of the present invention, the extraction unit includes an extraction tower.

[0114] In some embodiments of the present invention, preferably, the extraction unit further includes a vacuum drying tower connected to the raffinate outlet of the extraction tower and the liquid phase inlet of the hydrogenation reactor, for vacuum drying at least 10%, preferably at least 30% by mass flow rate of the raffinate, and returning the resulting desorbed liquid and the remaining raffinate to the hydrogenation unit.

[0115] In some embodiments of the present invention, preferably, the vacuum drying tower is also connected to the extractant inlet or oxidation liquid inlet of the extraction tower for returning water and / or organic matter obtained by vacuum drying of at least 10%, preferably at least 30% by mass flow rate of the raffinate to the extraction tower.

[0116] According to some embodiments of the present invention, the hydrogenation unit, oxidation unit and extraction unit in the system can be configured with reference to CN114426259A, and will not be described in detail here.

[0117] A second aspect of the present invention provides a method for preparing hydrogen peroxide, the method being carried out in the system described in the first aspect; wherein the method includes the following steps:

[0118] (1) In the presence of a hydrogenation catalyst, hydrogen-containing gas enters the reactor cylinder through N gas phase inlets, and is then dispersed into hydrogen-containing gas bubbles by N gas distributors. After contacting with the working liquid that enters the reactor cylinder through the liquid phase inlet, hydrogenation reactions are carried out independently in N catalyst bed sections. The resulting reaction products flow upward into the gas-liquid separation unit for gas-liquid separation to obtain hydrogenated liquid and hydrogen-containing tail gas. The hydrogenated liquid flows out through the liquid phase outlet. The catalyst bed is filled with the hydrogenation catalyst.

[0119] (2) The hydrogenated liquid is divided into liquid A and liquid B; liquid A is regenerated in the presence of a regeneration catalyst to obtain a regenerated hydrogenated liquid;

[0120] (3) The B liquid, the regenerated hydrogenated liquid and the oxygen-containing gas are subjected to an oxidation reaction to obtain an oxidized liquid;

[0121] (4) Extract the oxidizing solution to obtain a hydrogen peroxide solution and a raffinate, and return the raffinate to the working solution;

[0122] The mass flow rate ratio of liquid A to liquid B is 10-25:75-90.

[0123] In some embodiments of the present invention, preferably, in step (1), the hydrogenation reaction process includes:

[0124] a) The hydrogen-containing gas bubbles, after making a first contact with the working fluid through the first gas phase inlet and the first gas distributor, enter the first catalyst bed to carry out the first hydrogenation reaction and obtain the first reaction product;

[0125] b) The hydrogen-containing gas bubbles, after coming into a second contact with the first reaction product through the second gas phase inlet and the second gas distributor, enter the second catalyst bed to carry out a second hydrogenation reaction, and obtain the second reaction product;

[0126] c) The hydrogen-containing gas bubbles, after passing through the Nth gas phase inlet and the Nth gas distributor, come into contact with the (N-1)th reaction product for the Nth time, and then enter the Nth catalyst bed for the Nth hydrogenation reaction to obtain the reaction product.

[0127] In some embodiments of the present invention, the hydrogen-containing gas may be pure hydrogen, or a mixture of pure hydrogen and an inert gas; wherein, nitrogen is preferably the inert gas; preferably, the volume content of hydrogen in the hydrogen-containing gas is 40-100% by volume. After the system stabilizes, pure hydrogen is continuously added to the reactor according to the amount of hydrogen consumed in the reaction; as inert gas is lost, inert gas is intermittently added to the hydrogenation reactor.

[0128] Typically, the working solution is a solution prepared by dissolving an alkyl anthraquinone compound in an organic solvent. Preferably, the alkyl anthraquinone compound is selected from at least one of 2-alkyl-9,10-anthraquinone (i.e., 2-alkyl anthraquinone), 9,10-dialkyl anthraquinone (i.e., dialkyl anthraquinone), and their respective 5,6,7,8-tetrahydro derivatives. In the 2-alkyl-9,10-anthraquinone, the alkyl group can be a C1-C5 alkyl group, and non-limiting examples include methyl, ethyl, sec-butyl, tert-butyl, tert-pentyl, and isopentyl. In the 9,10-dialkyl anthraquinone, the two alkyl groups can be the same or different, and can be selected from C1-C5 alkyl groups, for example, methyl, ethyl, and tert-butyl. The dialkyl group on the 9,10-dialkyl anthraquinone is, for example, 1,3-dimethyl, 1,4-dimethyl, 2,7-dimethyl, 1,3-diethyl, 2,7-di(tert-butyl), or 2-ethyl-6-tert-butyl.

[0129] In some embodiments of the present invention, preferably, the organic solvent is a mixture of a nonpolar compound and a polar compound. The nonpolar compound may be a petroleum fraction with a boiling point above 140°C, whose main component is an aromatic hydrocarbon (heavy aromatic hydrocarbon) with 9 or more carbon atoms, such as isomers of trimethylbenzene, tetramethylbenzene, tert-butylbenzene, methylnaphthalene, and dimethylnaphthalene. The polar compound is preferably at least one of a saturated alcohol, a carboxylic acid ester, a phosphate ester, and a tetrasubstituted urea. The saturated alcohol is typically C7-C6.11 Saturated alcohols, non-limiting examples of which include: diisobutylmethanol, 3,5,5-trimethylhexanol, and isohepanol. The carboxylic acid ester is, for example, at least one selected from methylcyclohexyl acetate, heptyl acetate, butyl benzoate, and ethyl heptanoate. The phosphate ester is, for example, at least one selected from trioctyl phosphate, tri-2-ethylbutyl phosphate, tri-2-ethylhexyl phosphate, and tri-n-octyl phosphate. The tetrasubstituted urea is, for example, tetra-n-butylurea.

[0130] In some embodiments of the present invention, when the number of catalyst bed segments N = 3, the flow rate ratio of hydrogen-containing gas at the first, second, and third gas phase inlets from bottom to top is 0.6-0.3:0.5-0.2:0.4-0.1. The flow rate of hydrogen-containing gas can be allocated according to the reaction characteristics and actual needs; in the high conversion region, a low space velocity can be used to enhance the reaction.

[0131] In some embodiments of the present invention, preferably, the conditions for the first hydrogenation reaction, the second hydrogenation reaction, ... and the Nth hydrogenation reaction each independently include: a pressure of 0.03-0.35 MPa, preferably 0.05-0.25 MPa; and a temperature of 40-80°C, preferably 45-65°C.

[0132] In some embodiments of the present invention, preferably, m 3 The ratio of the working fluid to the hydrogenation catalyst (in tons) is 1-50:1, for example, 1:1, 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 40:1, 50:1, and any value within a range of any two values.

[0133] In some embodiments of the present invention, preferably, the amount of the working fluid is 1-50 ml relative to 1 t of hydrogenation catalyst. 3 Preferably 5-30m 3 .

[0134] In this invention, unless otherwise specified, m 3 The ratio of the working fluid to the hydrogenation catalyst in tons refers to the ratio of the working fluid to the hydrogenation catalyst packed in the N-section catalyst bed.

[0135] According to some embodiments of the present invention, preferably, in step (1), the ratio of the standard volumetric flow rate of the hydrogen-containing gas to the volumetric flow rate of the working liquid is 4-14:1, more preferably 5-10:1.

[0136] According to some embodiments of the present invention, preferably, step (1) further includes: discharging the hydrogen-containing tail gas and / or returning it as a circulating gas and mixing it with the hydrogen-containing gas; more preferably, pressurizing the hydrogen-containing tail gas and using the pressurized hydrogen-containing tail gas as the circulating gas.

[0137] According to some embodiments of the present invention, preferably, the method further includes: returning a portion of the hydrogenated liquid as a circulating hydrogenated liquid to the reactor shell through (N-1) circulating liquid phase inlets to carry out the hydrogenation reaction. Preferably, a portion of the hydrogenated liquid is subjected to a first cooling, and the resulting cooled hydrogenated liquid is used as the circulating hydrogenated liquid.

[0138] In some embodiments of the present invention, preferably, the temperature of the cooling hydrogenation liquid is 15-70°C, more preferably 20-50°C, and even more preferably 35-45°C. This setting reduces the temperature of the circulating hydrogenation liquid, thereby reducing the temperature rise of the catalyst bed.

[0139] In some embodiments of the present invention, preferably, the weight ratio of the circulating hydrogenation liquid to the hydrogenation liquid is 10-80:100, for example, 10:100, 15:100, 20:100, 30:100, 40:100, 50:100, 60:100, 80:100, and any value within any range of any two values, preferably 15-60:100, more preferably 15-50:100. This configuration, while reducing the temperature rise of the catalyst bed and ensuring the heat extraction effect of the fixed-bed reactor, minimizes the amount of circulating hydrogenation liquid, thus reducing energy consumption. On the one hand, it can extend the catalyst life and reduce the consumption caused by catalyst regeneration; it can reduce the regeneration load of the working fluid, reducing the consumption caused by working fluid regeneration and the amount of solid waste generated; and it can eliminate the need for working fluid regeneration in the alkali tower, improving the inherent safety of the device.

[0140] In this invention, unless otherwise specified, the hydrogenation liquid includes: a partial hydrogenation liquid and a remaining partial hydrogenation liquid, that is, the hydrogenation liquid includes a circulating hydrogenation liquid.

[0141] In some embodiments of the present invention, when the number of catalyst bed sections N = 3, the number of circulating liquid phase inlets is 2, and the flow rate ratio of the circulating liquid phase at the first circulating liquid phase inlet to the second circulating liquid phase inlet is 0.3-0.8:0.2-0.7 from bottom to top. This is beneficial for reducing the reaction temperature rise of each catalyst bed.

[0142] According to some embodiments of the present invention, preferably, in step (2), the regeneration reaction is carried out in a regeneration reactor, which is selected from a fixed-bed reactor and / or a slurry-bed reactor.

[0143] According to some embodiments of the present invention, preferably, when the regeneration reactor is a fixed-bed reactor, the regeneration catalyst is modified alumina; preferably, the modified alumina is selected from at least one metal-modified alumina selected from alkali metals, alkaline earth metals and rare earth metals.

[0144] According to some embodiments of the present invention, preferably, when the regeneration reactor is a slurry bed reactor, the regeneration catalyst is a modified molecular sieve; preferably, the modified molecular sieve is a molecular sieve modified from at least one metal selected from alkali metals, alkaline earth metals and rare earth metals.

[0145] According to some embodiments of the present invention, preferably, the regeneration reaction process in step (2) includes: exchanging heat between liquid A and regenerated hydrogenation liquid to obtain a heat exchange liquid and then carrying out the regeneration reaction; preferably, the regeneration reaction process in step (2) further includes: heating the heat exchange liquid and then carrying out the regeneration reaction.

[0146] According to some embodiments of the present invention, preferably, step (3) further includes: before the oxidation reaction, subjecting the first stream to a second cooling to obtain a second coolant, wherein the first stream comprises the B liquid and the regenerated hydrogenation liquid.

[0147] According to some embodiments of the present invention, preferably, step (3) further includes: before the oxidation reaction, mixing the second coolant with the first pH adjuster, and then filtering the resulting adjusting solution.

[0148] According to some embodiments of the present invention, preferably, the oxidation reaction in step (3) also yields an oxygen-containing tail gas, which is discharged externally and / or compressed and then returned to the oxygen-containing gas.

[0149] According to some embodiments of the present invention, preferably, in step (4), the extractant used in the extraction process is selected from water and optionally a second pH adjuster.

[0150] According to some embodiments of the present invention, preferably, step (4) further includes: before performing the extraction, subjecting the oxidizing liquid to a third cooling liquid to obtain a third cooling liquid.

[0151] According to some embodiments of the present invention, preferably, the method further includes: vacuum drying at least 10%, preferably at least 30% by mass flow rate of the raffinate, and returning the resulting stripping liquid and the remaining raffinate as a circulating working fluid to the working fluid.

[0152] According to some embodiments of the present invention, preferably, the vacuum drying also yields water and / or organic matter, and the water and / or organic matter is recycled back to step (4).

[0153] According to some embodiments of the present invention, in the method provided by the present invention, steps (2) to (4) can be performed with reference to CN114426259A, and will not be repeated here.

[0154] The system and method for preparing hydrogen peroxide provided by the present invention are described below with reference to the accompanying drawings.

[0155] This invention provides, by way of example, a schematic diagram of a system for preparing hydrogen peroxide according to a specific embodiment, such as... Figure 1 As shown, the system includes a hydrogenation unit, an oxidation unit, and an extraction unit connected in sequence; the hydrogenation unit is used to perform hydrogenation reaction and gas-liquid separation on hydrogen-containing gas 01 and working liquid 02 in sequence to obtain hydrogenated liquid 03 and hydrogen-containing tail gas 04, wherein the hydrogenated liquid 03 is divided into liquid A and liquid B.

[0156] The hydrogenation unit includes a hydrogenation reactor I, which is a fixed-bed reactor; the hydrogenation reaction and the gas-liquid separation are carried out in the hydrogenation reactor I.

[0157] The structural schematic diagram of the hydrogenation reactor I is shown below. Figure 2 As shown in the figure, the hydrogenation reactor I includes: a reactor body 1, a liquid phase inlet 2, N gas phase inlets 3 (N is a natural number and N≥2), a gas phase outlet 4, a liquid phase outlet 5, and (N-1) circulating liquid phase inlets 12 arranged on the reactor body 1; and N catalyst bed layers 6 and a gas-liquid separation component arranged sequentially from bottom to top inside the reactor body 1; a gas distributor 7 and a liquid distributor 13 are arranged sequentially below each catalyst bed layer 6, and the gas distributor 7 is connected to the gas phase inlet 3; wherein, the gas-liquid separation component includes a separation component cylinder 8, a baffle 9, an overflow pipe 10, and an anti-impact baffle 11 arranged inside the separation component cylinder 8, so that the gas-liquid separation component is divided into a two-phase zone, a liquid phase zone, and a gas phase zone; wherein, the liquid phase zone is provided with a liquid phase outlet 5; and the gas phase zone is provided with a gas phase outlet 4;

[0158] Among them, the included angle α between the baffle 9 and the separation component cylinder 8 is 45-90°; the included angle β between the baffle 9 and the overflow pipe 10 is 90-145°; the anti-impact baffle 11 is arranged above the overflow pipe 10, and the included angle γ is 110-145°.

[0159] Among them, the gas phase outlet 4 is connected to N gas phase inlets 3, and a compressor II is installed on the pipeline connecting the gas phase outlet 4 and the gas phase inlets 3 to pressurize the hydrogen-containing tail gas 04. The resulting pressurized hydrogen-containing tail gas 05 is returned to the hydrogenation unit as a circulating gas and mixed with hydrogen-containing gas 01. Each gas phase inlet 3 is equipped with a gas flow controller IV and a gas flow regulating valve X. The pipeline connecting the liquid phase inlet 2 is equipped with a liquid flow controller V and a liquid flow regulating valve XI.

[0160] Among them, from bottom to top, the second to the Nth section, each section of catalyst bed 6 is independently provided with a circulating liquid phase inlet 12 below it; the (N-1)th circulating liquid phase inlet 12 is located below the Nth gas phase inlet 3; a liquid flow controller V, a liquid flow regulating valve XI and a first cooler III are sequentially provided on the pipe connecting the circulating liquid phase inlet 12 and the liquid phase outlet 5.

[0161] The reactor cylinder 1 is equipped with a pressure controller VI at the top, and a pressure regulating valve XII is installed on the pipe connecting the gas phase outlet 4, the gas phase inlet 3 and the pressure controller VI.

[0162] The liquid phase zone is equipped with a liquid level controller VII, and the pipe connected to the liquid phase outlet 5 is equipped with a liquid level regulating valve XIII;

[0163] The hydrogenation unit also includes a regeneration reactor 14, which is connected to the liquid phase outlet 5 of the hydrogenation reactor I and the inlet of the oxidation unit, and is used to regenerate liquid A to obtain regenerated hydrogenated liquid 011.

[0164] The oxidation unit is used to oxidize the B liquid, the regenerated hydrogenated liquid 011 and the oxygen-containing gas 012 to obtain the oxidation liquid 08.

[0165] The extraction unit is used to extract the oxidizing liquid 08 to obtain hydrogen peroxide solution 09 and raffinate 010, and the raffinate 010 is returned to the hydrogenation unit;

[0166] The hydrogenation unit also includes a heat exchanger 15, which is connected to the liquid phase outlet 5 of the hydrogenation reactor I, the inlet of the regeneration reactor 14 and the regenerated hydrogenated liquid outlet of the regeneration reactor 14, for exchanging heat between the liquid A and the regenerated hydrogenated liquid 011.

[0167] The hydrogenation unit also includes a heater 16, which is connected to the A liquid outlet of the heat exchanger 15 and the inlet of the regeneration reactor 14, for heating the heat exchange liquid.

[0168] The hydrogenation unit further includes a second cooler 17, which is connected to the liquid phase outlet 5 of the hydrogenation reactor I, the outlet of the regeneration reactor 14, and the inlet of the oxidation unit. It is used to perform a second cooling on the first stream to obtain a second coolant before entering the oxidation unit. The first stream consists of liquid B and the regenerated hydrogenation liquid.

[0169] The hydrogenation unit further includes a precision filter 18, which is connected to the second coolant outlet of the second cooler 17 and the inlet of the oxidation unit, for filtering the second coolant.

[0170] The oxidation unit includes oxidation reactor VIII;

[0171] The oxidation unit also includes a third cooler 19, which is connected to the oxidation liquid outlet of the oxidation reactor VIII and the inlet of the extraction unit. The third cooler 19 is used to perform a third cooling on the oxidation liquid 08 to obtain a third coolant before it enters the extraction unit.

[0172] The extraction unit includes an extraction tower IX;

[0173] The extraction unit further includes a vacuum drying tower 20, which is connected to the raffinate outlet of the extraction tower IX and the liquid phase inlet 2 of the hydrogenation reactor I. The vacuum drying tower 20 is used to vacuum dry at least 10% (preferably at least 30%) of the raffinate by mass flow and return the resulting circulating working liquid 013 (removed liquid and remaining extract) to the hydrogenation unit.

[0174] The vacuum drying tower 20 is also connected to the extractant inlet or oxidation liquid inlet of the extraction tower IX, for returning at least 10%, preferably at least 30% by mass flow rate, of the raffinate obtained by vacuum drying to the extraction tower IX, along with water and / or organic matter 014.

[0175] The method is in Figure 1-2 The preparation of hydrogen peroxide is carried out in the system shown, including the following steps:

[0176] (1) In the presence of a hydrogenation catalyst, hydrogen-containing gas 01 enters the reactor cylinder 1 through N gas inlets 3, and is then dispersed into hydrogen-containing gas bubbles through N gas distributors 7. After contacting with the working liquid 02 that enters the reactor cylinder 1 through liquid inlets 2, hydrogenation reactions are carried out independently in N catalyst bed layers 6. The resulting reaction products flow upward into the gas-liquid separation unit for gas-liquid separation to obtain hydrogenated liquid 03 and hydrogen-containing tail gas 04. The hydrogenated liquid 03 flows out through the liquid outlet 5. The catalyst bed layer 6 is filled with the hydrogenation catalyst.

[0177] (2) The hydrogenated liquid 03 is divided into liquid A and liquid B; in the presence of a regeneration catalyst, liquid A is regenerated to obtain regenerated hydrogenated liquid 011;

[0178] (3) The B liquid, the regenerated hydrogenated liquid 011 and the oxygen-containing gas 012 are subjected to an oxidation reaction to obtain an oxidized liquid 08;

[0179] (4) Extract the oxidizing solution 08 to obtain hydrogen peroxide solution 09 and raffinate 010, and return the raffinate 010 to the working solution 02.

[0180] The mass flow rate ratio of liquid A to liquid B is 10-25:75-90;

[0181] Preferably, the hydrogen-containing exhaust gas 04 is pressurized, and the resulting pressurized hydrogen-containing exhaust gas 05 is returned as a circulating gas and mixed into the hydrogen-containing gas 01.

[0182] Preferably, a portion of the hydrogenated liquid 06 is subjected to a first cooling, and the resulting cooled hydrogenated liquid 07 is returned as a circulating hydrogenated liquid to carry out the hydrogenation reaction;

[0183] Preferably, after exchanging heat between liquid A and regenerated hydrogenation liquid 011, the resulting heat exchange liquid is heated before the regeneration reaction is carried out.

[0184] Preferably, before the oxidation reaction, the first stream is subjected to a second cooling to obtain a second coolant, wherein the first stream includes the B liquid and the regenerated hydrogenation liquid 011;

[0185] Preferably, before the oxidation reaction, the second coolant is mixed with the first pH adjuster 015, and the resulting adjusted liquid is then filtered.

[0186] Preferably, the oxidation reaction further yields oxygen-containing exhaust gas 016, and the oxygen-containing exhaust gas 016 is discharged externally and / or compressed and then returned to the oxygen-containing gas 012;

[0187] Preferably, the extractant 017 used in the extraction process is selected from water and an optional second pH adjuster;

[0188] Preferably, before the extraction is performed, the oxidizing liquid 08 is subjected to a third cooling to obtain a third cooling liquid;

[0189] Preferably, at least 10% (preferably at least 30%) of the raffinate 010 is vacuum dried, and the resulting stripped liquid and the remaining raffinate are returned to the working liquid 02 as a circulating working liquid 013.

[0190] Preferably, the vacuum drying also yields water and / or organic matter 014, and the water and / or organic matter 014 is recycled back to step (4).

[0191] The present invention will be described in detail below through embodiments. In the following embodiments and comparative examples:

[0192] The hydrogenation catalyst is a supported catalyst with an average particle size of 3-5 mm. The support for the hydrogenation catalyst is alumina, and the active metal is palladium or platinum. The content of the active metal is 0.3 wt% based on the total weight of the hydrogenation catalyst.

[0193] The working solution is an alkyl anthraquinone compound (2-alkyl-9,10-anthraquinone) dissolved in an organic solvent (petroleum fractions with boiling points above 140°C, C7-C4). 11 A solution prepared from saturated alcohols.

[0194] Hydrogen efficiency (hydrogenation efficiency) determination method: Take 5 mL of hydrogenated liquid into a separatory funnel, then add 10 mL of heavy aromatic hydrocarbon and 20 mL of 1+4H2SO4 solution (H2SO4 to water volume ratio is 1:4); bubble and oxidize the above mixed solution until it is bright yellow or orange-yellow (about 10-15 min); wash the extraction reaction solution with pure water 4-5 times, about 20 mL of water each time; titrate the extract with 0.1 mol / L KMnO4 standard solution until it turns slightly red, and the endpoint is when the color does not fade in 30 seconds;

[0195] Calculation method: Hydrogen efficiency (g·H2O2 / L) = standard solution concentration (0.1mol / L) × standard solution volume (mL) × 17.01 / 5.

[0196] Example 1

[0197] Adopting such Figure 1 The system for preparing hydrogen peroxide shown and as follows Figure 2 The hydrogenation reactor I shown is

[0198] The hydrogenation reactor I includes: a reactor body 1, a liquid inlet 2, three gas inlets 3, a gas outlet 4, a liquid outlet 5, and two circulating liquid inlets 12. Within the reactor body 1, three catalyst beds 6 and a gas-liquid separation component are arranged sequentially from bottom to top. Below each catalyst bed 6, a gas distributor 7 and a liquid distributor 13 are arranged sequentially, with the gas distributor 7 connected to the gas inlet 3. The gas-liquid separation component includes a separation component body 8, a baffle 9, an overflow pipe 10, and an anti-impact baffle 11 arranged within the separation component body 8, dividing the gas-liquid separation component into a two-phase zone, a liquid zone, and a gas zone. The liquid zone has a liquid outlet 5, and the gas zone has a gas outlet 4.

[0199] The reactor cylinder 1 has an inner diameter of 550 mm and a height of 6000 mm; each catalyst bed 6 has a height of 820 mm; and the gas-liquid separation component has a height of 800 mm.

[0200] Among them, the shortest distance d1 between the gas phase inlet 3 and the lower surface of the catalyst bed 6 is 0.2m; the gas distributor 7 is selected from microporous elements with a pore size of 10-100μm;

[0201] The ratio of the inner diameters of the separation component cylinder 8 and the reactor cylinder 1 is 1:1; the ratio of the heights of the overflow pipe 10 and the separation component cylinder 8 is 0.5:1; the cross-section of the overflow pipe 10 is circular, and the ratio of the inner diameters of the overflow pipe 10 and the separation component cylinder 1 is 0.5:1; the anti-collision baffle 11 is located above the overflow pipe 10, and the shortest distance between the anti-collision baffle 11 and the overflow pipe 10 is 0.3m; the included angle γ of the anti-collision baffle 11 is 120°.

[0202] Among them, the gas phase outlet 4 is connected to 3 gas phase inlets 3, and a compressor II is installed on the pipeline connecting the gas phase outlet 4 and the gas phase inlets 3; a gas flow controller IV and a gas flow regulating valve X are installed on the pipeline connecting the gas phase outlet 4 and the gas phase inlets 3; a liquid flow controller V and a liquid flow regulating valve XI are installed on the pipeline connecting the liquid phase inlet 2.

[0203] In this configuration, from bottom to top, the catalyst bed 6 of the second and third sections is independently provided with a circulating liquid phase inlet 12 below each; the first circulating liquid phase inlet 12 is located below the second gas phase inlet 3, and the second circulating liquid phase inlet 12 is located below the third gas phase inlet 3; a liquid flow controller V, a liquid flow regulating valve XI, and a first cooler III are sequentially provided on the pipe connecting the circulating liquid phase inlet 12 and the liquid phase outlet 5.

[0204] A pressure controller VI is installed on the pipe connecting the gas phase outlet 4 and the top of the reactor body 1; a pressure regulating valve XII is installed on the pipe connecting the gas phase outlet 4, the gas phase inlet 3 and the pressure controller VI; a liquid level controller VII is installed in the liquid phase zone, and a liquid level regulating valve XIII is installed on the pipe connecting the liquid phase outlet 5.

[0205] The method for preparing hydrogen peroxide includes the following steps: :

[0206] (1) In the presence of a hydrogenation catalyst, hydrogen-containing gas O1 (pure hydrogen, 30 Nm) is added. 3 / h) and working fluid O2 (4.8m 3 The hydrogenation reaction was carried out at a temperature of 40℃ and a flow rate of 1000 m / h. The reaction products were then subjected to gas-liquid separation to obtain hydrogenated liquid O3 (at a temperature of 50℃) and hydrogen-containing tail gas O4. The hydrogenated liquid O3 was then divided into liquid A and liquid B. The hydrogenation reaction process was as follows:

[0207] a) Hydrogen-containing gas bubbles passing through the first gas phase inlet and the first gas distributor come into first contact with the working liquid and then enter the first catalyst bed to carry out the first hydrogenation reaction, obtaining the first reaction product;

[0208] b) Hydrogen-containing gas bubbles passing through the second gas inlet and the second gas distributor come into a second contact with the first reaction product and the first stream of circulating hydrogenation liquid, and then enter the second catalyst bed to carry out a second hydrogenation reaction to obtain the second reaction product.

[0209] c) Hydrogen-containing gas bubbles passing through the third gas phase inlet and the third gas distributor come into third contact with the second reaction product and the second stream of circulating hydrogenation liquid, and then enter the third catalyst bed to carry out the third hydrogenation reaction to obtain the reaction product.

[0210] The flow rate ratio of hydrogen-containing gas at the three gas phase inlets is 0.5:0.3:0.2;

[0211] The conditions for the first hydrogenation reaction, the second hydrogenation reaction, and the third hydrogenation reaction are each independent: pressure of 0.25 MPa and temperature of 45 °C.

[0212] The catalyst bed is filled with the hydrogenation catalyst, and the amount of hydrogenation catalyst in each section of the catalyst bed is 100 kg.

[0213] Specifically, the hydrogen-containing tail gas 04 is pressurized to obtain pressurized hydrogen-containing tail gas 05, which is then returned as a circulating gas and mixed with hydrogen-containing gas 01; a portion of the hydrogenated liquid 06 is subjected to a first cooling process, and the resulting cooled hydrogenated liquid 07 (at a temperature of 40°C) is returned as a circulating hydrogenated liquid for hydrogenation reaction. The weight ratio of the portion of hydrogenated liquid 06 to hydrogenated liquid 03 is 50:100; the flow rate ratio of the first circulating hydrogenated liquid to the second circulating hydrogenated liquid is 0.6:0.4.

[0214] (2) The A liquid (15% mass flow rate of hydrogenated liquid) is passed through two hydrogenated clay beds (800 mm in diameter and 1700 mm in height) filled with activated alumina to regenerate the liquid to obtain regenerated hydrogenated liquid 011. The regeneration reaction temperature is 80℃.

[0215] (3) The mixture of liquid B (85% mass flow rate hydrogenated liquid) and the regenerated hydrogenated liquid 011 obtained in step (2) is cooled to 45°C by the second cooler 17 to obtain the second coolant. An 85% phosphoric acid solution is then injected to obtain an adjusting solution with a phosphoric acid content of 5 mg / L. This adjusting solution is then filtered through a precision filter 18 and introduced into the oxidation reactor VIII, where it reacts with 177 Nm³ of hydrogen. 3 / h air undergoes an oxidation reaction, wherein the oxidation reaction temperature is 50℃ and the pressure is 0.3MPa, yielding oxygen-containing tail gas 016 and oxidizing liquid 08;

[0216] (4) Dilute the 85% phosphoric acid aqueous solution to an acidic aqueous solution with a phosphoric acid content of 120 ppm, and extract the oxidizing solution 08 and the acidic aqueous solution in an extraction tower at a mass flow ratio of 37:1 to obtain raffinate 010 and hydrogen peroxide solution 09, wherein the hydrogen peroxide content in hydrogen peroxide solution 09 is 27.5 wt%.

[0217] (5) After the raffinate 010 is dehydrated by a vacuum drying tower, the resulting dehydrated liquid and the remaining raffinate are returned to the hydrogenation unit as circulating working liquid 013 and mixed into working liquid 02. The pressure of the vacuum drying tower is 5 kPa and the temperature is 70°C.

[0218] Technical effect The hydrogen efficiency of the hydrogenation liquid is 9.3-9.4 g / L, and the hydrogenation selectivity is 98%-99%. The unit operated for 2100 hours, during which 1.2 tons of activated alumina were replaced. The activity and selectivity of the reactor catalyst remained stable, with no signs of deactivation. The effective anthraquinone content in the working solution remained stable.

[0219] Example 2

[0220] The method is the same as in Example 1, except that in step (2), liquid A (10% mass flow rate of hydrogenated liquid) is regenerated by passing it through two hydrogenated clay beds (800 mm in diameter and 1700 mm in height) containing activated alumina to obtain regenerated hydrogenated liquid 011. The regeneration reaction temperature is 60°C, and the other steps and conditions are the same to obtain hydrogen peroxide solution (hydrogen peroxide content is 27.5 wt%).

[0221] Technical effect The hydrogen efficiency of the hydrogenation liquid is 9.3-9.4 g / L, and the hydrogenation selectivity is 98%-99%. The unit operated for 2100 hours, during which 1.2 tons of activated alumina were replaced. The reactor catalyst activity and selectivity remained stable, with no signs of deactivation. The effective anthraquinone content in the working solution decreased by 3%.

[0222] Comparative Example 1

[0223] The system according to Example 1;

[0224] The method of Example 1 is the same except that the step of separating the hydrogenated liquid 03 into liquid A and liquid B is not performed. Instead, the hydrogenated liquid 03 is directly cooled by the second cooler. The remaining steps and conditions are the same to obtain a hydrogen peroxide solution (the content of hydrogen peroxide is 27.5 wt%).

[0225] Technical effectThe hydrogen efficiency of the hydrogenation solution is 9.0-9.4 g / L, and the hydrogenation selectivity is 95%-99%. The unit operated for 2100 hours, during which 1.2 tons of activated alumina were replaced. In the initial stage of the reaction, the catalyst activity and selectivity were stable, and no signs of deactivation were observed. The effective anthraquinone content in the working solution decreased by 5%. As time went on, the catalyst activity and selectivity gradually showed a downward trend.

[0226] Comparative Example 2

[0227] The system according to Example 1;

[0228] The method of Example 1 is different except that part of the hydrogenated liquid is not used as the circulating hydrogenated liquid. That is, in step (1), the temperature of hydrogenated liquid 03 is 60°C, and the other steps and conditions are the same to obtain a hydrogen peroxide solution (the content of hydrogen peroxide is 27.5 wt%).

[0229] Technical effect The hydrogen efficiency of the hydrogenation liquid is 8.9-9.1 g / L, and the hydrogenation selectivity is 94%-96%. The unit operated for 2100 hours, during which 1.2 tons of activated alumina were replaced. The activity and selectivity of the reactor catalyst decreased, but no obvious signs of deactivation were observed. The effective anthraquinone content in the working fluid decreased by 8%.

[0230] Comparative Example 3

[0231] The system according to Example 1 differs in that the fixed-bed hydrogenation reactor (550 mm in diameter and 4000 mm in height) contains a catalyst bed (2500 mm in height, filled with hydrogenation catalyst), and the catalyst bed is not segmented; that is, there is only one catalyst bed, and the working liquid enters from the bottom gas phase inlet and liquid phase inlet and is distributed by the distributor.

[0232] The method of Example 1 is different except that part of the hydrogenated liquid is not used as the circulating hydrogenated liquid. That is, in step (1), the temperature of hydrogenated liquid 03 is 60°C, and the other steps and conditions are the same to obtain a hydrogen peroxide solution (the content of hydrogen peroxide is 27.5 wt%).

[0233] Technical effect The hydrogen efficiency of the hydrogenation liquid is 8.4-8.9 g / L, and the hydrogenation selectivity is 89%-94%. The unit operated for 1800 hours, during which 1.0 t of activated alumina was replaced. The reactor catalyst activity and selectivity decreased, showing signs of deactivation, and the effective anthraquinone content in the working fluid decreased by 12%.

[0234] Comparative Example 4

[0235] The system for preparing hydrogen peroxide uses a fixed-bed reactor as described in Comparative Example 3; hydrogen-containing gas 01 (pure hydrogen, 30 Nm³) 3 / h) and working fluid O2 (4.8m 3The reaction product (at a temperature of 40℃) enters the reactor from the top inlet. The pressure at the top of the reactor is 0.3MPa, and the temperature at the bottom of the reactor is 60℃. The reaction product flows out from the bottom of the reactor into the gas-liquid separator to obtain hydrogenated liquid 03 and hydrogen-containing tail gas 04. The hydrogen-containing tail gas 04 is discharged from the system, and the hydrogenated liquid 03 is divided into liquid A and liquid B.

[0236] Following steps (2) to (5) of Example 1, a hydrogen peroxide solution (containing 27.5 wt% hydrogen peroxide) was obtained.

[0237] Technical effect The hydrogen efficiency of the hydrogenation liquid is 7.6-8.7 g / L, and the hydrogenation selectivity is 80%-92%. After 800 hours of operation, during which 0.46 t of activated alumina was replaced, the activity and selectivity of the reactor catalyst decreased significantly, indicating obvious deactivation. The effective anthraquinone content in the working solution decreased by 16%.

[0238] The results above show that the system and method provided by this invention can significantly improve the hydrogen efficiency of fixed-bed alkyl anthraquinone hydrogenation, increasing the hydrogenation selectivity to over 98%. This effectively improves the selectivity of the hydrogenation reaction, the efficiency of the equipment, and extends the service life of the catalyst, resulting in significant economic and social benefits.

[0239] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A system for preparing hydrogen peroxide, characterized in that, The system comprises a hydrogenation unit, an oxidation unit, and an extraction unit connected in sequence; wherein: The hydrogenation unit is used to sequentially perform hydrogenation reaction and gas-liquid separation on hydrogen-containing gas and working fluid to obtain hydrogenated liquid and hydrogen-containing tail gas. The hydrogenated liquid is divided into liquid A and liquid B. The hydrogenation unit includes a hydrogenation reactor, which is a fixed-bed reactor. The hydrogenation reactor includes: a reactor shell, a liquid phase inlet, N gas phase inlets, a liquid phase outlet, and a gas phase outlet arranged sequentially from bottom to top on the reactor shell, and N catalyst bed layers and a gas-liquid separation component arranged sequentially from bottom to top within the reactor shell; wherein, N is a natural number and N≥2; the height-to-diameter ratio of the catalyst bed layer is 1:0.5-5. Each catalyst bed is provided with a gas distributor below it, and the gas distributor is connected to the gas inlet; the shortest distance d1 between the gas inlet and the lower surface of the catalyst bed is 0.1-1.5m; the gas distributor is selected from perforated tubes or microporous elements; The gas-liquid separation component is divided into a two-phase region, a liquid phase region, and a gas phase region; the liquid phase region is provided with a liquid phase outlet; and the gas phase region is provided with a gas phase outlet. The hydrogenation unit further includes a regeneration reactor, which is connected to the liquid phase outlet of the hydrogenation reactor and the inlet of the oxidation unit, and is used to regenerate liquid A to obtain regenerated hydrogenated liquid. The oxidation unit is used to oxidize the B liquid, the regenerated hydrogenated liquid, and the oxygen-containing gas to obtain an oxidized liquid. The extraction unit is used to extract the oxidizing liquid to obtain a hydrogen peroxide solution and a raffinate, and the raffinate is returned to the hydrogenation unit.

2. The system according to claim 1, wherein, The catalyst bed has 2-8 segments; And / or, the aperture of the perforated tube is 0.5-12 mm; the aperture of the microporous element is 0.2-500 μm; And / or, a liquid distributor is provided below each section of the catalyst bed, and the liquid distributor is located below the gas distributor.

3. The system according to claim 2, wherein, The catalyst bed has 3-5 segments.

4. The system according to claim 1 or 2, wherein, The height-to-diameter ratio of the catalyst bed is 1:0.8-3.

5. The system according to claim 1 or 2, wherein, The shortest distance d1 between the gas phase inlet and the lower surface of the catalyst bed is 0.2-0.8m.

6. The system according to claim 2, wherein, The diameter of the perforated tube is 1-8 mm.

7. The system according to claim 2, wherein, The pore size of the microporous element is 0.5-200μm.

8. The system according to claim 1, wherein, The gas-liquid separation component includes a separation component cylinder, and a baffle, an overflow pipe, and an anti-impact baffle disposed within the separation component cylinder; And / or, the area formed by the overflow pipe and the anti-surge baffle is the two-phase region; the area formed by the baffle and the inner wall of the separator cylinder is the liquid phase region; the area formed by the anti-surge baffle and the inner wall of the separator cylinder is the gas phase region; And / or, the ratio of the inner diameter of the separation component cylinder to the inner diameter of the reactor cylinder is 0.2-1.5:1; And / or, the included angle α between the baffle and the separation component cylinder is 45°-90°, and the included angle β between the baffle and the overflow pipe is 90°-145°; And / or, the inner diameter ratio of the overflow pipe and the separator cylinder is 0.15-0.75:1; And / or, the height ratio of the overflow pipe to the separation component cylinder is 0.2-0.95:1; And / or, the anti-rush baffle is disposed above the overflow pipe; And / or, the anti-impact baffle is a conical structure.

9. The system according to claim 8, wherein, The ratio of the inner diameter of the separation component cylinder to the inner diameter of the reactor cylinder is 0.5-1:

1.

10. The system according to claim 8, wherein, The ratio of the inner diameter of the overflow pipe to the inner diameter of the separation component cylinder is 0.2-0.6:

1.

11. The system according to claim 8, wherein, The height ratio of the overflow pipe to the separation component cylinder is 0.5-0.8:

1.

12. The system according to claim 8, wherein, The shortest distance between the lower edge of the anti-collision baffle and the upper end of the overflow pipe is 0.3-1.2m.

13. The system according to claim 12, wherein, The shortest distance between the lower edge of the anti-collision baffle and the upper end of the overflow pipe is 0.3-0.8m.

14. The system according to claim 8, wherein, The anti-impact baffle has a conical structure with an included angle γ of 110°-145°.

15. The system according to any one of claims 1-3, wherein, The liquid phase inlet is located at the bottom of the reactor shell; the gas phase outlet is located at the top of the reactor shell. And / or, the gas phase outlet is connected to N of the gas phase inlets; And / or, a gas flow controller is provided on the pipe of each of the gas phase inlets.

16. The system according to claim 15, wherein, The gas phase outlet is connected to N gas phase inlets, and a compressor is installed on the pipeline connecting the gas phase outlet and the gas phase inlets.

17. The system according to claim 15, wherein, A gas flow regulating valve is installed on the pipeline connecting the gas phase inlet and the gas flow controller, and the gas flow regulating valve is located between the gas phase inlet and the gas flow controller.

18. The system according to any one of claims 1-3, wherein, The hydrogenation reactor further includes (N-1) circulating liquid phase inlets connected to the liquid phase outlet, and each of the circulating liquid phase inlets is independently arranged on the reactor body; And / or, from bottom to top, the second to the Nth segment, each segment of the catalyst bed has its own independently provided circulating liquid phase inlet below it; And / or, from bottom to top, the (N-1)th circulating liquid phase inlet is located below the Nth gas phase inlet; And / or, the shortest distance d2 between the circulating liquid phase inlet and the bottom of the catalyst bed is 0.2-1.2m; And / or, a first cooler is provided on the pipe connecting the circulating liquid phase inlet and the liquid phase outlet; And / or, a liquid flow controller is also provided on the pipe connecting the circulating liquid phase inlet and the liquid phase outlet, and the liquid flow controller is located before the first cooler; And / or, a liquid flow regulating valve is also provided on the pipe connecting the circulating liquid phase inlet and the liquid phase outlet, and the liquid flow regulating valve is located between the liquid flow controller and the circulating cooler.

19. The system according to claim 18, wherein, The shortest distance d2 between the circulating liquid phase inlet and the bottom of the catalyst bed is 0.3-0.8m.

20. The system according to any one of claims 1-3, wherein, A pressure controller is installed at the top of the reactor cylinder; And / or, the liquid phase zone is equipped with a liquid level controller.

21. The system according to claim 20, wherein, A pressure regulating valve is installed on the pipeline connecting the gas phase outlet, gas phase inlet and pressure controller.

22. The system according to claim 20, wherein, A liquid level regulating valve is installed on the pipe connected to the liquid phase outlet.

23. A method for preparing hydrogen peroxide, characterized in that, The method is performed in the system described in any one of claims 1-22; wherein the method includes the following steps: (1) In the presence of a hydrogenation catalyst, hydrogen-containing gas enters the reactor cylinder through N gas phase inlets, and is then dispersed into hydrogen-containing gas bubbles by N gas distributors. After contacting with the working liquid that enters the reactor cylinder through the liquid phase inlet, hydrogenation reactions are carried out independently in N catalyst bed sections. The resulting reaction products flow upward into the gas-liquid separation unit for gas-liquid separation to obtain hydrogenated liquid and hydrogen-containing tail gas. The hydrogenated liquid flows out through the liquid phase outlet. The catalyst bed is filled with the hydrogenation catalyst. (2) The hydrogenated liquid is divided into liquid A and liquid B; in the presence of a regeneration catalyst, liquid A is regenerated to obtain a regenerated hydrogenated liquid; (3) The B solution, the regenerated hydrogenated liquid, and the oxygen-containing gas are subjected to an oxidation reaction to obtain an oxidized liquid; (4) Extract the oxidizing solution to obtain a hydrogen peroxide solution and a raffinate, and return the raffinate to the working solution; The mass flow rate ratio of liquid A to liquid B is 10-25:75-90.

24. The method according to claim 23, wherein, In step (1), the hydrogenation reaction process includes: a) The hydrogen-containing gas bubbles passing through the first gas phase inlet and the first gas distributor, after making a first contact with the working fluid, enter the first catalyst bed to carry out the first hydrogenation reaction and obtain the first reaction product; b) The hydrogen-containing gas bubbles, after coming into a second contact with the first reaction product through the second gas phase inlet and the second gas distributor, enter the second catalyst bed to carry out a second hydrogenation reaction, and obtain the second reaction product; c) The hydrogen-containing gas bubbles passing through the Nth gas phase inlet and the Nth gas distributor come into contact with the (N-1)th reaction product for the Nth time, and then enter the Nth catalyst bed to carry out the Nth hydrogenation reaction to obtain the reaction product; And / or, the conditions for the first hydrogenation reaction, the second hydrogenation reaction... and the Nth hydrogenation reaction each independently include: a pressure of 0.03-0.35 MPa and a temperature of 40-80 °C; And / or, with m 3 The ratio of the working fluid (in tons) to the hydrogenation catalyst (in tons) is 1-50:

1.

25. The method according to claim 24, wherein, The conditions for the first hydrogenation reaction, the second hydrogenation reaction, ... and the Nth hydrogenation reaction each independently include a pressure of 0.05-0.25 MPa.

26. The method according to claim 24, wherein, The conditions for the first hydrogenation reaction, the second hydrogenation reaction, ... and the Nth hydrogenation reaction each independently include a temperature of 45-65°C.

27. The method according to claim 23, wherein, In step (1), the ratio of the standard volumetric flow rate of the hydrogen-containing gas to the volumetric flow rate of the working liquid is 4-14:1; And / or, step (1) further includes: discharging the hydrogen-containing exhaust gas and / or returning it as a recirculating gas and mixing it into the hydrogen-containing gas; And / or, the method further includes: returning a portion of the hydrogenated liquid as a circulating hydrogenated liquid and performing the hydrogenation reaction; And / or, the temperature of the cooling hydrogenated liquid is 15-70°C; And / or, the weight ratio of the circulating hydrogenated liquid to the hydrogenated liquid is 10-80:

100.

28. The method according to claim 27, wherein, The ratio of the standard volumetric flow rate of the hydrogen-containing gas to the volumetric flow rate of the working fluid is 5-10:

1.

29. The method according to claim 27, wherein, A portion of the hydrogenated liquid is subjected to a first cooling process, and the resulting cooled hydrogenated liquid is used as the circulating hydrogenated liquid.

30. The method according to claim 27, wherein, The temperature of the cooling hydrogenated liquid is 20-50℃.

31. The method according to claim 30, wherein, The temperature of the cooling hydrogenated liquid is 35-45℃.

32. The method according to claim 27, wherein, The weight ratio of the circulating hydrogenated liquid to the hydrogenated liquid is 15-60:

100.

33. The method according to claim 32, wherein, The weight ratio of the circulating hydrogenated liquid to the hydrogenated liquid is 15-50:

100.

34. The method according to any one of claims 23-33, wherein, In step (2), the regeneration reaction is carried out in a regeneration reactor, which is selected from a fixed-bed reactor and / or a slurry-bed reactor; And / or, when the regeneration reactor is a fixed-bed reactor, the regeneration catalyst is modified alumina; And / or, when the regeneration reactor is a slurry bed reactor, the regeneration catalyst is a modified molecular sieve; And / or, the regeneration reaction process in step (2) includes: exchanging heat between liquid A and the regenerated hydrogenated liquid to obtain a heat exchange liquid and then carrying out the regeneration reaction.

35. The method according to claim 34, wherein, The modified alumina is selected from at least one metal-modified alumina selected from alkali metals, alkaline earth metals, and rare earth metals.

36. The method according to claim 34, wherein, The modified molecular sieve is a molecular sieve modified from at least one of alkali metals, alkaline earth metals, and rare earth metals.

37. The method of claim 34, wherein, The regeneration reaction process in step (2) further includes heating the heat exchange liquid before carrying out the regeneration reaction.

38. The method according to any one of claims 23-33, wherein, Step (3) further includes: before the oxidation reaction, subjecting the first stream to a second cooling to obtain a second coolant, wherein the first stream includes the B liquid and the regenerated hydrogenation liquid.

39. The method according to claim 38, wherein, Step (3) further includes: before the oxidation reaction, mixing the second coolant with the first pH adjuster, and then filtering the resulting adjusted liquid.

40. The method of claim 38, wherein, The oxidation reaction in step (3) also produces oxygen-containing tail gas, which is discharged externally and / or compressed and then returned to the oxygen-containing gas.

41. The method according to any one of claims 23-33, wherein, In step (4), the extractant used in the extraction process is selected from water and an optional second pH adjuster; And / or, step (4) further includes: subjecting the oxidizing liquid to a third cooling before the extraction to obtain a third cooling liquid.

42. The method according to any one of claims 23-33, wherein, The method further includes: vacuum drying at least 10% of the mass flow rate of the raffinate, and returning the resulting stripped liquid and the remaining raffinate as a circulating working liquid to the working liquid; And / or, the vacuum drying also yields water and / or organic matter, and the water and / or organic matter is recycled back to step (4).

43. The method according to claim 42, wherein, The method further includes: vacuum drying at least 30% of the mass flow rate of the raffinate, and returning the resulting stripped liquid and the remaining raffinate as a circulating working liquid to the working liquid.

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