Hydrogen peroxide preparation hydrogenation reaction system and control method thereof

Abstract

The invention belongs to the technical field of hydrogen peroxide preparation, and particularly relates to a hydrogen peroxide preparation hydrogenation reaction system and a control method thereof.The hydrogenation reaction system comprises a working solution supply unit, a hydrogen supply unit, a working solution supply unit, a catalyst supply unit and a hydrogenation tower; the output ends of the working solution supply unit, the hydrogen supply unit, the working solution supply unit and the catalyst supply unit are respectively connected with the hydrogenation reactor, the hydrogenation reaction system further comprises a filtering unit and a working solution recovery unit, and the filtering unit is located between the hydrogenation tower and the hydrogenation solution input end of the oxidation process; and the working solution recovery unit is positioned between the organic phase output end of the extraction process and the hydrogenation tower. By additionally arranging the filtering unit, hydrogenation liquid can be pretreated, catalyst particles and degradation products in the hydrogenation liquid are removed, catalyst loss, equipment blockage and side reaction increase caused by the fact that the hydrogenation liquid enters an oxidation procedure are avoided, and it is guaranteed that subsequent oxidation reaction is stably carried out.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen peroxide preparation technology, specifically relating to a hydrogen peroxide preparation hydrogenation reaction system and its control method. Background Technology

[0002] Hydrogen peroxide, as a green and environmentally friendly oxidant, is widely used in chemical synthesis, pharmaceutical disinfection, environmental remediation, food processing and other fields. The efficiency and stability of its industrial production process have always been the focus of industry research.

[0003] Currently, the anthraquinone process is the mainstream technology for hydrogen peroxide preparation. This process uses anthraquinone compounds (working solution) as a carrier and cyclically prepares hydrogen peroxide through processes such as hydrogenation, oxygen oxidation, and water extraction. Among these processes, the hydrogenation reaction is the core step in reducing anthraquinone to hydrogen anthraquinone, which directly determines the efficiency of subsequent oxidation reactions and the yield of hydrogen peroxide. The performance of the reaction system has a critical impact on the energy consumption, material consumption, and product quality of the entire production process.

[0004] However, the hydrogenated liquid generated after the hydrogenation reaction often contains unreacted catalyst particles and a small amount of degradation products. If it is directly introduced into the oxidation process, it will lead to catalyst loss, blockage of the oxidation reactor, or an increase in side reactions.

[0005] Furthermore, hydrogen peroxide production technology employs a three-phase mixed flow of gas, solid, and liquid. The mixing effect of hydrogen, working fluid, and catalyst within the hydrogenation tower directly affects the hydrogenation reaction rate and selectivity. Existing hydrogenation towers often use single-channel or simple porous structures for their gas phase distribution devices. This results in uneven distribution of hydrogen after it enters from the bottom of the tower, leading to excessively high flow velocities in the center and excessively low flow velocities on the periphery. Consequently, the catalyst does not contact the hydrogen sufficiently, resulting in low reaction conversion rates. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a hydrogen peroxide preparation hydrogenation reaction system and its control method. By adding a filtration unit, the hydrogenated liquid can be pretreated to remove catalyst particles and degradation products, preventing them from entering the oxidation process and causing catalyst loss, equipment blockage, and increased side reactions, thus ensuring the stable progress of subsequent oxidation reactions.

[0007] The specific technical solution adopted in this invention is as follows:

[0008] A hydrogen peroxide preparation hydrogenation reaction system includes a working fluid supply unit, a hydrogen supply unit, a nitrogen supply unit, a catalyst supply unit, and a hydrogenation tower. The outputs of the working fluid supply unit, hydrogen supply unit, nitrogen supply unit, and catalyst supply unit are respectively connected to a hydrogenation reactor. The hydrogenation reaction system also includes a filtration unit and a working fluid recovery unit. The hydrogenated liquid output of the hydrogenation tower is connected to the input of the filtration unit, and the output of the filtration unit is connected to the hydrogenated liquid input of the oxidation process. The input of the working fluid recovery unit is connected to the organic phase output of the extraction process, and the output of the working fluid recovery unit is connected to the working fluid input of the hydrogenation tower.

[0009] The filtration unit includes a filter, which has multiple stages. The filtration unit also includes a diversion pipeline, a fine filtration pipeline, and a coarse filtration pipeline. The input ends of the multiple stages of the filter are connected in parallel to the hydrogenated liquid output end of the hydrogenation tower via the diversion pipeline. The output ends of the multiple stages of the filter are connected in parallel to the input end of the oxidation process via the coarse filtration pipeline. The output end of the previous stage filter is connected to the input end of the next stage filter via the fine filtration pipeline. Each of the diversion pipeline, fine filtration pipeline, and coarse filtration pipeline is equipped with a shut-off valve.

[0010] The working fluid recovery unit includes a dehydration tank, a working fluid clay bed, and a heat exchanger. The input end of the dehydration tank is connected to the organic phase output end of the extraction process, forming the input end of the working fluid recovery unit. The organic phase output end of the dehydration tank is connected to the tube-side input end of the heat exchanger. The tube-side output end of the heat exchanger is connected to the input end of the working fluid clay bed. The output end of the working fluid clay bed is connected to the working fluid input end of the hydrogenation tower, forming the output end of the working fluid recovery unit. The shell-side input end of the heat exchanger is connected to the hydrogenated liquid output end of the hydrogenation tower. The shell-side output end of the heat exchanger is connected to the input end of the filtration unit.

[0011] The hydrogenation tower includes a tower body. The hydrogen and nitrogen gas inlet, working liquid inlet, and catalyst outlet of the hydrogenation tower are located at the bottom of the tower body. The catalyst inlet and working liquid inlet of the hydrogenation tower share a common pipe. The hydrogenated liquid outlet of the hydrogenation tower is located at the waist of the tower body, and the hydrogen gas outlet of the hydrogenation tower is located at the top of the tower body.

[0012] A gas phase distributor is provided at the bottom of the chamber of the tower body. The gas phase distributor includes a cover plate, a bottom groove, and a flow guiding component sandwiched between the cover plate and the bottom groove. Multiple sets of the flow guiding components are arranged in a ring array with the center of the bottom groove as the center. The gap between adjacent flow guiding components forms a flow guiding channel. The multiple sets of flow guiding channels are distributed in a vortex shape. An exhaust port is provided on the cover plate at the location of the flow guiding channel. The hydrogen and nitrogen gas inlet passes through the center of the bottom groove and is connected to the flow guiding channel.

[0013] The flow guiding assembly includes an arc-shaped first guide plate and a second guide plate. The second guide plate is located outside the first guide plate and is spaced apart from the first guide plate. The center of the first guide plate overlaps with the center of the second guide plate. An annular transition air passage is formed between the first guide plate and the second guide plate. An inner flow guiding channel is formed between adjacent first guide plates, and an outer flow guiding channel is formed between adjacent second guide plates. A first exhaust port is provided on the cover plate at the location of the inner flow guiding channel, and a second exhaust port is provided on the cover plate at the location of the outer flow guiding channel.

[0014] The control method specifically includes the following steps:

[0015] Adjust the concentration of the working fluid, the pressure of the hydrogenation tower, the temperature of the hydrogenation tower, the pressure of hydrogen, and the amount of catalyst. The settings of the above parameters should conform to the following equation:

[0016]

[0017] Among them, dc AQ This is the derivative of anthraquinone concentration;

[0018] C cat This refers to the catalyst concentration.

[0019] C AQ Anthraquinone concentration;

[0020] P H2 This refers to the partial pressure of hydrogen gas.

[0021] C AQH2 This represents the concentration of hydrogenated anthraquinone.

[0022] The beneficial effects of this invention are:

[0023] 1. The present invention adds a filtration unit to pretreat the hydrogenation liquid, removing catalyst particles and degradation products, thus preventing catalyst loss, equipment blockage and increased side reactions caused by their entry into the oxidation process, and ensuring the stable progress of subsequent oxidation reactions; at the same time, the organic phase produced by the extraction process contains unreacted working liquid, so a working liquid recovery unit is also added to recover the working liquid in the organic phase and return it to the hydrogenation tower for recycling, reducing the amount of fresh working liquid replenishment and reducing raw material consumption.

[0024] 2. The gas phase distributor in this invention separates the airflow into an inner and outer swirling flow, forming an annular transition channel between them. Firstly, the high-velocity inner airflow disperses its pressure upon entering the annular transition channel, transferring some energy to the channel and preventing localized turbulence in the hydrogenation center due to excessive swirling. Meanwhile, the low-velocity outer airflow, through mixing with the airflow in the transition channel, replenishes its energy, maintaining the stability of the swirling flow in the edge region. This ensures that the radial velocity of the airflow does not fluctuate excessively.

[0025] 3. This invention establishes a hydrogenation reaction kinetic model, demonstrating the effects of working fluid concentration, hydrogenation tower pressure, hydrogenation tower temperature, hydrogen pressure, and catalyst dosage on the reaction rate. In actual production, the optimal parameter combination can be quickly calculated using real-time data such as raw material composition fluctuations and equipment operating status, ensuring that the reaction is always within the high-efficiency conversion range, improving the generation efficiency and selectivity of anthraquinone, reducing the occurrence of side reactions such as anthraquinone degradation, reducing the impact of human operation errors on product quality, and significantly improving the stability and economy of hydrogen peroxide production. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the present invention;

[0027] Figure 2 This is a schematic diagram of the hydrogenation tower.

[0028] Figure 3 This is a schematic cross-sectional view of the gas phase distributor.

[0029] Figure 4 This is a top view of the gas phase distributor.

[0030] In the attached diagram, 1 is the tower body, 2 is the hydrogen / nitrogen inlet, 3 is the working fluid inlet, 4 is the catalyst inlet, 5 is the catalyst outlet, 6 is the hydrogenated liquid outlet, 7 is the hydrogen outlet, 8 is the gas phase distributor, 9 is the cover plate, 10 is the bottom tank, 11 is the first guide plate, 12 is the second guide plate, 13 is the first exhaust port, and 14 is the second exhaust port. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0032] Specific embodiments, such as Figure 1 As shown, this invention provides a hydrogen peroxide preparation hydrogenation reaction system, including a working fluid supply unit, a hydrogen supply unit, a catalyst supply unit, and a hydrogenation tower. The outputs of the working fluid supply unit, hydrogen supply unit, nitrogen supply unit, and catalyst supply unit are respectively connected to the hydrogenation reactor. The hydrogenation reaction system also includes a filtration unit and a working fluid recovery unit. The hydrogenated liquid output of the hydrogenation tower is connected to the input of the filtration unit, and the output of the filtration unit is connected to the hydrogenated liquid input of the oxidation process. The input of the working fluid recovery unit is connected to the organic phase output of the extraction process, and the output of the working fluid recovery unit is connected to the working fluid input of the hydrogenation tower.

[0033] The invention adds a filtration unit to pretreat the hydrogenation liquid, removing catalyst particles and degradation products to prevent them from entering the oxidation process and causing catalyst loss, equipment blockage, and increased side reactions, thus ensuring the stable progress of subsequent oxidation reactions. At the same time, the organic phase produced in the extraction process contains unreacted working liquid, so a working liquid recovery unit is added to recover the working liquid in the organic phase and return it to the hydrogenation tower for recycling, reducing the amount of fresh working liquid replenishment and reducing raw material consumption.

[0034] like Figure 1 As shown, the filtration unit includes a filter, which has multiple stages. The filtration unit also includes a diversion pipeline, a fine filtration pipeline, and a coarse filtration pipeline. The input ends of the multiple stages of the filter are connected in parallel to the hydrogenated liquid output end of the hydrogenation tower via the diversion pipeline. The output ends of the multiple stages of the filter are connected in parallel to the input end of the oxidation process via the coarse filtration pipeline. The output end of the previous stage filter is connected to the input end of the next stage filter via the fine filtration pipeline. Each of the diversion pipeline, fine filtration pipeline, and coarse filtration pipeline is equipped with a shut-off valve.

[0035] By coordinating the various shut-off valves on the fine filtration and coarse filtration lines, the hydrogenated liquid can be filtered to different degrees according to actual needs.

[0036] To improve production efficiency, the shut-off valve on the fine filter line can be closed and the shut-off valve on the coarse filter line can be opened. The hydrogenated liquid discharged from the hydrogenation tower will be diverted to each stage of filter. After completing one filtration, the hydrogenated liquid will be sent directly to the oxidation process.

[0037] To improve product quality, the shut-off valve on the fine filter line can be opened, the shut-off valve on the coarse filter line can be closed, and all shut-off valves on the branch line except the one corresponding to the first-stage filter can be closed. The hydrogenated liquid discharged from the hydrogenation tower will enter the first-stage filter for primary filtration, then enter the next-stage filter for secondary filtration, and finally pass through the final-stage filter before being sent to the oxidation process. Multiple filtrations can ensure the quality of the hydrogenated liquid.

[0038] like Figure 1 As shown, the working fluid recovery unit includes a dehydration tank, a working fluid clay bed, and a heat exchanger. The input end of the dehydration tank is connected to the organic phase output end of the extraction process to form the input end of the working fluid recovery unit. The organic phase output end of the dehydration tank is connected to the tube-side input end of the heat exchanger. The tube-side output end of the heat exchanger is connected to the input end of the working fluid clay bed. The output end of the working fluid clay bed is connected to the working fluid input end of the hydrogenation tower to form the output end of the working fluid recovery unit. The shell-side input end of the heat exchanger is connected to the hydrogenated liquid output end of the hydrogenation tower. The shell-side output end of the heat exchanger is connected to the input end of the filtration unit.

[0039] Water reduces catalyst activity; therefore, a dehydration tank is installed to remove moisture from the organic phase, preventing water from entering the hydrogenation tower and affecting the hydrogenation reaction efficiency. The working fluid, in a clay bed, adsorbs residual degradation products (such as anthraquinone derivatives) from the organic phase, reducing their interference with the hydrogenation reaction and extending the working fluid's recycling cycle. A heat exchanger utilizes the waste heat from the hydrogenation liquid to reheat and recover the working fluid, reducing preheating energy consumption for subsequent hydrogenation reactions.

[0040] like Figure 2 As shown, the hydrogenation tower includes a tower body 1. The hydrogen and nitrogen gas inlet 2, the working liquid inlet 3, and the catalyst outlet 5 of the hydrogenation tower are located at the bottom of the tower body 1. The catalyst inlet 4 and the working liquid inlet 3 of the hydrogenation tower share a common port. The hydrogenated liquid outlet 6 of the hydrogenation tower is located at the waist of the tower body 1, and the hydrogen gas outlet 7 of the hydrogenation tower is located at the top of the tower body 1.

[0041] Catalyst inlet 4 and working liquid inlet 3 share a single port. The catalyst is suspended in the working liquid. Hydrogen and nitrogen gas are introduced from the bottom of the column, agitating the solid catalyst in the working liquid. After initial mixing at the bottom of the column, the three phases flow upwards, prolonging the contact time. The hydrogenated liquid is discharged from the waist outlet to prevent unreacted materials from being discharged prematurely and to reduce the entrainment of hydrogen gas from the top into the hydrogenated liquid.

[0042] like Figure 2-4 As shown, a gas phase distributor 8 is provided at the bottom of the chamber of the tower body 1. The gas phase distributor 8 includes a cover plate 9, a bottom groove 10, and a flow guiding assembly sandwiched between the cover plate 9 and the bottom groove 10. Multiple sets of the flow guiding assembly are arranged in a ring array with the center of the bottom groove 10 as the center. The gap between adjacent flow guiding assemblies forms a flow guiding channel. The multiple sets of flow guiding channels are distributed in a vortex shape. An exhaust port is provided on the cover plate 9 at the location of the flow guiding channel. The hydrogen and nitrogen gas inlet 2 passes through the center of the bottom groove 10 and communicates with the flow guiding channel.

[0043] Existing hydrogenation towers often employ single-channel or simple porous structures for their gas phase distribution devices. This results in uneven distribution of hydrogen gas after it enters from the bottom of the tower, leading to excessively high flow velocities in the middle and excessively low flow velocities on the periphery. Consequently, the catalyst does not come into sufficient contact with the hydrogen gas, resulting in a low reaction conversion rate.

[0044] Therefore, the flow channels of the gas phase distributor in this invention are distributed in a vortex shape. When hydrogen gas is guided to diffuse from the central inlet to the surrounding area through the vortex-shaped flow channels, a swirling flow is formed. Centrifugal force is used to make the hydrogen gas evenly distributed to the bottom cross section of the tower, avoiding the problem of excessively high flow velocity at the center and excessively low flow velocity at the edge.

[0045] In addition, the exhaust port on the cover plate corresponds to the flow channel to ensure that the swirling gas is discharged upward, reduce lateral disturbance, and allow the hydrogen to continue to mix with the liquid and solid phases during the rising process, thereby increasing the reaction rate.

[0046] like Figure 3-4As shown, the flow guiding assembly includes an arc-shaped first guide plate 11 and a second guide plate 12. The second guide plate 12 is located outside the first guide plate 11 and is spaced apart from the first guide plate 11. The center of the first guide plate 11 overlaps with the center of the second guide plate 12. An annular transition air passage is formed between the first guide plate 11 and the second guide plate 12. An inner flow guiding channel is formed between adjacent first guide plates 11, and an outer flow guiding channel is formed between adjacent second guide plates 12. A first exhaust port 13 is provided on the cover plate 9 at the location of the inner flow guiding channel, and a second exhaust port 14 is provided on the cover plate 9 at the location of the outer flow guiding channel.

[0047] Traditional single-channel gas phase distribution devices cause gas to decay along a single swirling path, meaning the swirling intensity gradually weakens from the inlet to the outlet. This easily leads to a slow-flowing zone with insufficient turbulence at the end of the path, which prevents the solid catalyst from being well dispersed in the hydrogenation tower. The catalyst tends to concentrate in a certain area, affecting the reaction conversion rate.

[0048] The gas phase distributor in this invention separates the airflow into inner and outer swirling streams, forming an annular transition channel between them. Firstly, the high-velocity inner airflow disperses its pressure upon entering the annular transition channel, transferring some energy to the channel and preventing localized turbulence in the central region of the hydrogenation tower caused by excessive swirling. Meanwhile, the low-velocity outer airflow, through mixing with the airflow in the transition channel, replenishes its energy, maintaining the stability of the swirling flow at the edge. This ensures that the radial velocity of the airflow does not fluctuate excessively.

[0049] The control method specifically includes the following steps:

[0050] Adjust the concentration of the working fluid, the pressure of the hydrogenation tower, the temperature of the hydrogenation tower, the pressure of hydrogen, and the amount of catalyst. The settings of the above parameters should conform to the following equation:

[0051]

[0052] Among them, dc AQ This is the derivative of anthraquinone concentration;

[0053] C cat This refers to the catalyst concentration.

[0054] C AQ Anthraquinone concentration;

[0055] P H2 This refers to the partial pressure of hydrogen gas.

[0056] C AQH2 This represents the concentration of hydrogenated anthraquinone.

[0057] By establishing a kinetic model of the hydrogenation reaction, the effects of working fluid concentration, hydrogenation tower pressure, hydrogenation tower temperature, hydrogen pressure, and catalyst dosage on the reaction rate were demonstrated. In actual production, the optimal parameter combination can be quickly calculated based on real-time data such as raw material composition fluctuations and equipment operating status, ensuring that the reaction is always in the high-efficiency conversion range, improving the generation efficiency and selectivity of anthraquinone, reducing the occurrence of side reactions such as anthraquinone degradation, reducing the impact of human operation errors on product quality, and significantly improving the stability and economy of hydrogen peroxide production.

Claims

1. A hydrogen peroxide preparation and hydrogenation reaction system, comprising a working fluid supply unit, a hydrogen supply unit, a nitrogen supply unit, a catalyst supply unit, and a hydrogenation tower, wherein the outputs of the working fluid supply unit, the hydrogen supply unit, the nitrogen supply unit, and the catalyst supply unit are respectively connected to a hydrogenation reactor, characterized in that, The hydrogenation reaction system also includes a filtration unit and a working liquid recovery unit. The hydrogenated liquid output end of the hydrogenation tower is connected to the input end of the filtration unit, the output end of the filtration unit is connected to the hydrogenated liquid input end of the oxidation process, the input end of the working liquid recovery unit is connected to the organic phase output end of the extraction process, and the output end of the working liquid recovery unit is connected to the working liquid input end of the hydrogenation tower.

2. The hydrogen peroxide preparation hydrogenation reaction system according to claim 1, characterized in that, The filtration unit includes a filter, which has multiple stages. The filtration unit also includes a diversion pipeline, a fine filtration pipeline, and a coarse filtration pipeline. The input ends of the multiple stages of the filter are connected in parallel to the hydrogenated liquid output end of the hydrogenation tower via the diversion pipeline. The output ends of the multiple stages of the filter are connected in parallel to the input end of the oxidation process via the coarse filtration pipeline. The output end of the previous stage filter is connected to the input end of the next stage filter via the fine filtration pipeline. Each of the diversion pipeline, fine filtration pipeline, and coarse filtration pipeline is equipped with a shut-off valve.

3. The hydrogen peroxide preparation hydrogenation reaction system according to claim 1, characterized in that, The working fluid recovery unit includes a dehydration tank, a working fluid clay bed, and a heat exchanger. The input end of the dehydration tank is connected to the organic phase output end of the extraction process, forming the input end of the working fluid recovery unit. The organic phase output end of the dehydration tank is connected to the tube-side input end of the heat exchanger. The tube-side output end of the heat exchanger is connected to the input end of the working fluid clay bed. The output end of the working fluid clay bed is connected to the working fluid input end of the hydrogenation tower, forming the output end of the working fluid recovery unit. The shell-side input end of the heat exchanger is connected to the hydrogenated liquid output end of the hydrogenation tower. The shell-side output end of the heat exchanger is connected to the input end of the filtration unit.

4. The hydrogen peroxide preparation hydrogenation reaction system according to claim 1, characterized in that, The hydrogenation tower includes a tower body (1), with the hydrogen and nitrogen gas inlet (2), working liquid inlet (3) and catalyst outlet (5) located at the bottom of the tower body (1). The catalyst inlet (4) and working liquid inlet (3) of the hydrogenation tower share a common port. The hydrogenated liquid outlet (6) of the hydrogenation tower is located at the waist of the tower body (1), and the hydrogen gas outlet (7) of the hydrogenation tower is located at the top of the tower body (1).

5. The hydrogen peroxide preparation hydrogenation reaction system according to claim 4, characterized in that, A gas phase distributor (8) is provided at the bottom of the chamber of the tower body (1). The gas phase distributor (8) includes a cover plate (9), a bottom groove (10), and a flow guiding component sandwiched between the cover plate (9) and the bottom groove (10). The flow guiding component is arranged in a ring array with the center of the bottom groove (10) as the center. The gap between adjacent flow guiding components forms a flow guiding channel. The multiple flow guiding channels are distributed in a vortex shape. An exhaust port is provided on the cover plate (9) at the location of the flow guiding channel. The hydrogen-nitrogen gas inlet (2) passes through the center of the bottom groove (10) and is connected to the flow guiding channel.

6. The hydrogen peroxide preparation hydrogenation reaction system according to claim 5, characterized in that, The flow guiding assembly includes an arc-shaped first guide plate (11) and a second guide plate (12). The second guide plate (12) is located outside the first guide plate (11) and is spaced apart from the first guide plate (11). The center of the first guide plate (11) overlaps with the center of the second guide plate (12). An annular transition air passage is formed between the first guide plate (11) and the second guide plate (12). An inner flow guiding channel is formed between adjacent first guide plates (11), and an outer flow guiding channel is formed between adjacent second guide plates (12). A first exhaust port (13) is provided on the cover plate (9) at the location of the inner flow guiding channel, and a second exhaust port (14) is provided on the cover plate (9) at the location of the outer flow guiding channel.

7. A control method for a hydrogen peroxide preparation hydrogenation reaction system, used for controlling the hydrogen peroxide preparation hydrogenation reaction system as described in claim 1, characterized in that, The control method specifically includes the following steps: Adjust the concentration of the working fluid, the pressure of the hydrogenation tower, the temperature of the hydrogenation tower, the pressure of hydrogen, and the amount of catalyst. The settings of the above parameters should conform to the following equation: Among them, dc AQ This is the derivative of anthraquinone concentration; C cat This refers to the catalyst concentration. C AQ Anthraquinone concentration; P H2 This refers to the partial pressure of hydrogen gas. C AQH2 This represents the concentration of hydrogenated anthraquinone.

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