Hydrogen and nitrogen circulation and self-cleaning system in hydrogen peroxide production device

Abstract

The application discloses a hydrogen-nitrogen circulation and self-cleaning system in a hydrogen peroxide production device, which comprises a hydrogenation tower, a hydrogenation tail gas cooler, a hydrogenation tail gas condensate measuring tank, a hydrogen-nitrogen circulation compressor, a hydrogen-nitrogen filter and an aromatic hydrocarbon recovery device. The system can not only recycle and utilize the hydrogen-nitrogen, avoid resource waste caused by a large amount of hydrogen exhaust, but also can flush the by-product degradation material covering the catalyst surface in the hydrogenation tower by using the recycled nitrogen, effectively restore the surface activity of the catalyst, and thus continuously self-clean, improve the catalytic efficiency and prolong the service life of the catalyst.

Description

Technical Field

[0001] This invention relates to the field of chemical process equipment technology, and in particular to a hydrogen-nitrogen gas circulation and self-cleaning system in a hydrogen peroxide production unit. Background Technology

[0002] Currently, in existing hydrogen peroxide production plants, excess unreacted hydrogen is often directly vented, leading to a waste of hydrogen resources and significant air pollution. Furthermore, the anthraquinone process is commonly used in hydrogen peroxide production, where the hydrogenation catalyst is a key technology. Catalyst lifespan is a crucial indicator of its quality and a significant factor affecting the operating cost of the hydrogen peroxide plant. In existing hydrogen peroxide production plants, after a period of use, the anthraquinone degradation products gradually increase due to side reactions in the system. These degradation products cover the catalyst surface and cause blockage, reducing the active sites for the catalyst to participate in the reaction and thus lowering hydrogenation efficiency. Therefore, it is necessary to switch the hydrogen peroxide plant to nitrogen operation by shutting down hydrogen supply. Nitrogen gas is used to flush away some of the by-product degradation products and alumina dust covering the catalyst surface, increasing catalyst surface activity and thus improving hydrogenation efficiency. However, current conventional flushing methods require stopping the hydrogen supply and using external nitrogen to flush the unit before reuse, a maintenance process that significantly impacts hydrogenation efficiency. Therefore, there is an urgent need to design a system that can achieve high hydrogen utilization, high catalytic efficiency, and long service life, so as to apply it to hydrogen peroxide production equipment, improve hydrogen utilization efficiency, and at the same time ensure that the equipment has the characteristics of long service life and high efficiency. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a hydrogen and nitrogen circulation and self-cleaning system for a hydrogen peroxide production device, which solves the problems of low hydrogen utilization and short catalyst life in existing hydrogen peroxide production devices, thereby overcoming the shortcomings of the prior art.

[0004] To solve the above-mentioned technical problems, the present invention discloses a hydrogen-nitrogen gas circulation and self-cleaning system in a hydrogen peroxide production device, comprising:

[0005] A hydrogenation tower, the inlet of which is connected to the hydrogen outlet of the hydrogen production system, and the outlet of which is connected to the inlet of the hydrogenation tail gas cooler;

[0006] A hydrogenation tail gas cooler, the outlet of which is connected to the first inlet of a hydrogenation tail gas condensate metering tank;

[0007] A hydrogenation tail gas condensate metering tank is provided with a first outlet, a nitrogen inlet, a waste liquid discharge outlet and a tail gas emission outlet. The first outlet is connected to the inlet of a hydrogen-nitrogen circulation compressor, the nitrogen inlet is connected to the nitrogen outlet of a nitrogen generation system, the waste liquid discharge outlet is connected to a wastewater treatment system, and the tail gas emission outlet is connected to a tail gas treatment system.

[0008] A hydrogen-nitrogen recirculating compressor, wherein the outlet of the hydrogen-nitrogen recirculating compressor is connected to the inlet of a hydrogen-nitrogen filter;

[0009] A hydrogen-nitrogen filter, the outlet of which is connected to the pipeline between the inlet of the hydrogenation tower and the hydrogen outlet of the hydrogen production system.

[0010] As an improvement of the present invention, a first flow meter and a first regulating valve are installed on the pipeline between the inlet of the hydrogenation tower and the outlet of the hydrogen production system. The first flow meter is used to measure the flow rate of hydrogen from the hydrogen production system into the hydrogenation tower, and the first regulating valve is used to control the flow rate of hydrogen from the hydrogen production system into the hydrogenation tower. The first regulating valve is interlocked with the first flow meter, and the opening of the first regulating valve is adjusted by the output value of the first flow meter to control the flow rate of hydrogen entering the hydrogenation tower.

[0011] As a further improvement of the present invention, the hydrogenation tower is provided with a first pressure transmitter, and the pipeline connected to the outlet of the hydrogenation tower is provided with a second regulating valve. The second regulating valve is used to control and regulate the internal pressure of the hydrogenation tower. The first pressure transmitter is interlocked with the second regulating valve, and the opening degree of the second regulating valve is controlled by monitoring the internal pressure change of the hydrogenation tower through the first pressure transmitter.

[0012] As a further improvement of the present invention, a second flow meter and a third regulating valve are provided on the pipeline connected to the nitrogen inlet in the hydrogenation tail gas condensate metering tank. The second flow meter is used to measure the flow rate of nitrogen introduced into the hydrogenation tail gas condensate metering tank by the nitrogen generation system, and the third regulating valve is used to control the flow rate of nitrogen introduced into the hydrogenation tail gas condensate metering tank. A second pressure transmitter is provided on the hydrogenation tail gas condensate metering tank. The second pressure transmitter is interlocked with the third regulating valve. The opening degree of the third regulating valve is controlled by monitoring the pressure change inside the hydrogenation tail gas condensate metering tank through the second pressure transmitter.

[0013] As a further improvement of the present invention, a fourth regulating valve is provided on the pipeline connected to the waste liquid discharge outlet of the hydrogenation tail gas condensate metering tank. The fourth regulating valve is used to control the liquid discharge volume in the hydrogenation tail gas condensate metering tank and maintain a stable liquid level in the tank. A level gauge is provided on the hydrogenation tail gas condensate metering tank. The level gauge is interlocked with the fourth regulating valve. The opening degree of the fourth regulating valve is controlled by monitoring the change in liquid level in the hydrogenation tail gas condensate metering tank through the level gauge.

[0014] As an improvement of the present invention, a third flow meter and a fifth regulating valve are provided on the pipeline connected to the tail gas emission outlet in the hydrogenation tail gas condensate metering tank. The third flow meter is used to measure the amount of hydrogenation tail gas emitted in the hydrogenation tail gas condensate metering tank, and the fifth regulating valve is used to control the amount of hydrogenation tail gas emitted in the hydrogenation tail gas condensate metering tank, thereby controlling the inert gas components in the hydrogenation tail gas condensate metering tank and the hydrogenation tower.

[0015] As a further improvement of the present invention, a bypass pipeline is provided between the inlet and outlet of the hydrogen-nitrogen circulating compressor, and a sixth regulating valve is provided on the bypass pipeline. The sixth regulating valve is used to control the hydrogen and nitrogen pressure in the hydrogen-nitrogen circulating compressor. A third pressure transmitter is provided on the pipeline connected to the outlet of the hydrogen-nitrogen circulating compressor. The third pressure transmitter is interlocked with the sixth regulating valve, and the opening degree of the sixth regulating valve is controlled by monitoring the hydrogen and nitrogen pressure in the hydrogen-nitrogen circulating compressor through the third pressure transmitter.

[0016] As a further improvement of the present invention, the system also includes an aromatic hydrocarbon recovery device, which is equipped with a temperature-switching adsorption unit. The inlet of the aromatic hydrocarbon recovery device is connected to the tail gas emission outlet of the hydrogenation tail gas condensate metering tank, the tail gas outlet of the aromatic hydrocarbon recovery device is vented, and the liquid outlet of the aromatic hydrocarbon recovery device is connected to the aromatic hydrocarbon recovery system.

[0017] As a further improvement of the present invention, the first regulating valve, the second regulating valve, the third regulating valve, the fourth regulating valve, the fifth regulating valve and the sixth regulating valve are all pneumatic switching valves; the first flow meter, the first flow meter and the third flow meter are all mass flow meters.

[0018] As a further improvement of the present invention, the system also includes a distributed control system. The first flow meter, the third flow meter, and the fourth flow meter are respectively connected to the distributed control system to realize on-site and centralized display and have cumulative metering function. The first pressure transmitter, the second pressure transmitter, and the third pressure transmitter are respectively connected to the distributed control system, and the output values ​​of the first pressure transmitter, the second pressure transmitter, and the third pressure transmitter are respectively transmitted to the distributed control system. The first regulating valve, the second regulating valve, the third regulating valve, the fourth regulating valve, the fifth regulating valve, and the sixth regulating valve are respectively connected to the distributed control system, and the opening degree is controlled by the distributed control system.

[0019] With this design, the present invention has at least the following advantages:

[0020] (1) In the hydrogen peroxide production device of the present invention, the hydrogen-nitrogen gas circulation and self-cleaning system connects the tail gas pipeline of the hydrogenation tower to the hydrogenation tail gas condensate metering tank, and connects the first outlet of the hydrogenation tail gas condensate metering tank to the inlet pipeline of the hydrogen-nitrogen gas circulation compressor. Nitrogen and hydrogen that have not been completely reacted are buffered in the hydrogenation tail gas condensate metering tank and compressed by the hydrogen-nitrogen gas circulation compressor. The circulated hydrogen-nitrogen gas is filtered by the filter and enters the hydrogenation tower together with the raw material hydrogen gas, so that the hydrogen-nitrogen gas is recycled and reused, avoiding the waste of resources caused by the discharge of a large amount of hydrogen gas.

[0021] (2) In the hydrogen peroxide production device of the present invention, the hydrogen-nitrogen circulation and self-cleaning system can wash away some of the by-product degradation products and alumina dust covering the catalyst surface through circulating nitrogen, effectively restoring the surface activity of the catalyst, playing a continuous self-cleaning role, regenerating the catalyst in the hydrogenation tower, slowing down the replacement cycle, and extending the service life and lifespan of the catalyst.

[0022] (3) In the hydrogen peroxide production apparatus of the present invention, the hydrogen-nitrogen circulation and self-cleaning system is achieved by setting a nitrogen replenishment pipeline at the nitrogen inlet of the hydrogenation tail gas condensate metering tank, and connecting the pressure transmitter of the hydrogenation tail gas condensate metering tank to the regulating valve on the nitrogen replenishment pipeline. Through the interlocking of the regulating valve and the pressure transmitter, the internal pressure of the hydrogenation tail gas condensate metering tank can be stabilized. At the same time, a tail gas discharge pipeline is connected to the tail gas discharge outlet of the hydrogenation tail gas condensate metering tank, which can quantitatively and periodically discharge inert gas, thereby reducing the accumulation of inert gas in the hydrogenation tower and regulating the gas composition and hydrogen partial pressure in the hydrogenation tower.

[0023] (4) The hydrogen peroxide production device of the present invention is equipped with an aromatic hydrocarbon recovery device in the hydrogen nitrogen gas circulation and self-cleaning system, which can recover the aromatic hydrocarbons contained in the hydrogenation tail gas, reduce the consumption of aromatic raw materials, reduce the volatile organic compounds in the hydrogenation tail gas, make the exhaust gas meet the standards, and reduce pollution. Attached Figure Description

[0024] The above is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Figure 1 This is a schematic diagram of the system structure of the hydrogen-nitrogen gas circulation and self-cleaning system in the hydrogen peroxide production device in this embodiment of the invention.

[0026] Figure 2 This is a schematic diagram of the equipment connection of the hydrogen-nitrogen gas circulation and self-cleaning system in the hydrogen peroxide production device in this embodiment of the invention.

[0027] Meaning of reference numerals in the attached figures:

[0028] 1-Hydrogenation tower; 2-Hydrogenation tail gas cooler; 3-Hydrogenation tail gas condensate metering tank; 4-Hydrogen-nitrogen circulating compressor; 5-Hydrogen-nitrogen filter; 6-Aromatic hydrocarbon recovery unit; 7-Flow meter one; 8-Control valve one; 9-Pressure transmitter one; 10-Control valve two; 11-Flow meter two; 12-Control valve three; 13-Pressure transmitter two; 14-Control valve four; 15-Level gauge; 16-Flow meter three; 17-Control valve five; 18-Control valve six; 19-Pressure transmitter three. Detailed Implementation

[0029] Examples of embodiments described in this invention are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the invention, and should not be construed as limiting the invention.

[0030] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0031] Combination Figure 1 and Figure 2 As shown, this embodiment specifically discloses a hydrogen-nitrogen gas circulation and self-cleaning system in a hydrogen peroxide production device, which includes:

[0032] Hydrogenation tower 1 is mainly used as a reaction device for hydrogenation reaction in the hydrogen peroxide production process. The inlet of hydrogenation tower 1 is connected to the hydrogen outlet of the hydrogen production system, which is used to provide raw material hydrogen. The hydrogen production system can use existing mature equipment. The outlet of hydrogenation tower 1 is connected to the inlet of hydrogenation tail gas cooler 2.

[0033] Hydrogenation tail gas cooler 2 is used to condense and cool the hydrogenation tail gas generated by hydrogenation tower 1 to remove moisture from the tail gas. The outlet of the hydrogenation tail gas cooler 2 is connected to the first inlet of the hydrogenation tail gas condensate metering tank 3.

[0034] The hydrogenation tail gas condensate metering tank 3 is equipped with a first outlet, a nitrogen inlet, a waste liquid discharge outlet, and a tail gas emission outlet. The first outlet is connected to the inlet of the hydrogen-nitrogen circulating compressor 4, the nitrogen inlet is connected to the nitrogen outlet of the nitrogen generation system, the waste liquid discharge outlet is connected to the sewage treatment system, and the tail gas emission outlet is connected to the tail gas treatment system. The hydrogenation tail gas condensate metering tank 3 is used to separate the hydrogenation tail gas and the condensed liquid, and to adjust the internal pressure of the tank and change the hydrogen-nitrogen composition by adding nitrogen or discharging tail gas.

[0035] The hydrogen-nitrogen gas recirculation compressor 4 is used to compress hydrogen and nitrogen gas, and the outlet of the hydrogen-nitrogen gas recirculation compressor 4 is connected to the inlet of the hydrogen-nitrogen gas filter 5.

[0036] The hydrogen-nitrogen filter 5 filters the hydrogen and nitrogen compressed by the hydrogen-nitrogen circulating compressor 4 and then re-introduces it into the inlet of the hydrogenation tower 1. The outlet of the hydrogen-nitrogen filter 5 is connected to the pipeline between the inlet of the hydrogenation tower 1 and the hydrogen outlet of the hydrogen production system.

[0037] In this embodiment, the system addresses the issue that existing hydrogen peroxide production devices often release large amounts of unreacted hydrogen, resulting in wasted hydrogen energy. Therefore, this system incorporates a recycling device for the hydrogenation tail gas. This device sends hydrogen and nitrogen to a nitrogen-hydrogen recycling compressor for compression, which then serves as a supplement to the raw material gas. This allows the hydrogenation tail gas, which was originally meant to be vented, to be recycled, reducing the consumption of raw material hydrogen and lowering the raw material cost of the device.

[0038] Furthermore, in this embodiment, a flow meter 7 and a regulating valve 8 are installed on the pipeline between the inlet of the hydrogenation tower 1 and the outlet of the hydrogen production system. The flow meter 7 is used to measure the flow rate of hydrogen from the hydrogen production system into the hydrogenation tower 1, and the regulating valve 8 is used to control the flow rate of hydrogen from the hydrogen production system into the hydrogenation tower 1. The regulating valve 8 is interlocked with the flow meter 7, and the opening of the regulating valve 8 is adjusted by the output value of the flow meter 7 to control the flow rate of hydrogen entering the hydrogenation tower 1. Preferably, in this embodiment, the regulating valve 8 is connected to a distributed control system via a line. After receiving the data from the flow meter 7, the distributed control system controls the opening of the regulating valve 8, thereby achieving quantitative control of the hydrogen content inside the hydrogenation tower 1 to control the reaction process inside the hydrogenation tower 1. It should be noted that the distributed control system in this embodiment can adopt existing mature technologies.

[0039] More specifically, in this embodiment, the hydrogen peroxide production process in hydrogenation tower 1 needs to be carried out under certain temperature and pressure conditions. Furthermore, due to the continuous introduction of hydrogen gas and the presence of unreacted hydrogen gas inside hydrogenation tower 1, the internal pressure of hydrogenation tower 1 will increase during the reaction. To control the internal pressure of hydrogenation tower 1 to remain constant, residual tail gas needs to be discharged from hydrogenation tower 1 in a timely manner. Therefore, in this embodiment, a pressure transmitter 9 is installed on hydrogenation tower 1, and a regulating valve 10 is installed on the pipeline connected to the outlet of hydrogenation tower 1. The pressure transmitter 9 monitors the pressure changes inside hydrogenation tower 1, and the regulating valve 10... The second regulating valve 10 is used to control and regulate the internal pressure of the hydrogenation tower 1. By interlocking the pressure transmitter 9 with the regulating valve 10, when the internal pressure of the hydrogenation tower 1 changes, the regulating valve 10 will automatically adjust its opening according to the output value of the pressure transmitter 9 to control the discharge of hydrogenation tail gas. For example, if the internal pressure of the hydrogenation tower 1 is too high, the opening of the regulating valve 10 will be increased to increase the discharge of hydrogenation tail gas. When the internal pressure of the hydrogenation tower 1 is too low, the opening of the regulating valve 10 will be decreased to reduce the discharge of hydrogenation tail gas, thereby balancing the internal pressure of the hydrogenation tower 1.

[0040] In this embodiment, the hydrogen content in the hydrogenation tail gas discharged from the hydrogenation tower 1 is relatively high. Direct discharge would result in hydrogen waste and increase the cost of hydrogen raw materials. Therefore, in this embodiment, the hydrogenation tail gas discharged from the hydrogenation tower 1 is treated and recycled. The hydrogenation tail gas is first condensed by the hydrogenation tail gas cooler 2 to separate the water in the tail gas and then passed into the hydrogenation tail gas condensate metering tank 3. In this embodiment, the hydrogenation tail gas condensate metering tank 3 can separate the hydrogenation tail gas from the water. The condensed water waste liquid is discharged through the sewage outlet, while the hydrogenation tail gas is stored in the hydrogenation tail gas condensate metering tank 3.

[0041] During the hydrogen peroxide production process, after a period of use, the anthraquinone degradation products gradually increase due to the side reactions in the system. These degradation products cover the catalyst surface and cause blockage, thereby reducing the active sites of the catalyst and lowering the hydrogenation efficiency. Therefore, it is necessary to switch from hydrogen production to nitrogen production, using nitrogen to flush away some of the by-product degradation products and alumina dust covering the catalyst surface, thereby increasing the catalyst surface activity and improving the hydrogenation efficiency. In this embodiment, nitrogen is mixed with hydrogen to perform nitrogen flushing simultaneously with the hydrogenation reaction, allowing the hydrogenation reaction and catalyst cleaning process to run in parallel. This ensures both the stability of the hydrogenation process and the surface activity of the catalyst. Therefore, in this embodiment, a nitrogen inlet is provided in the hydrogenation tail gas condensate metering tank 3. A flow meter 2 11 and a regulating valve 3 12 are installed on the pipe connected to the nitrogen inlet. The flow meter 2 11 is used to measure the flow rate of nitrogen introduced into the hydrogenation tail gas condensate metering tank 3 from the nitrogen generation system. The regulating valve 3 12 is used to control the flow rate of nitrogen introduced into the hydrogenation tail gas condensate metering tank 3. Furthermore, a pressure transmitter 2 13 is installed on the hydrogenation tail gas condensate metering tank 3. The pressure transmitter 2 13 is interlocked with the regulating valve 3 12. The pressure transmitter 2 13 monitors the internal pressure changes of the hydrogenation tail gas condensate metering tank 3 to control the opening degree of the regulating valve 3 12. In this embodiment, the regulating valve 3 12 and the pressure transmitter 2 13 are respectively connected to a distributed control system via lines. After receiving data from the pressure transmitter 2 13, the distributed control system controls the opening degree of the regulating valve 3 12.

[0042] Furthermore, a regulating valve 14 is installed on the pipe connected to the waste liquid discharge outlet of the hydrogenation tail gas condensate metering tank 3. The regulating valve 14 is used to control the liquid discharge from the hydrogenation tail gas condensate metering tank 3 and maintain a stable liquid level in the tank. Further, a level gauge 15 is installed on the hydrogenation tail gas condensate metering tank 3, preferably a remote level gauge. The level gauge 15 is interlocked with the regulating valve 14. The opening of the regulating valve 14 is controlled by monitoring the liquid level change in the hydrogenation tail gas condensate metering tank 3 through the level gauge 15, so as to maintain a constant liquid level in the hydrogenation tail gas condensate metering tank 3.

[0043] Furthermore, in this embodiment, if nitrogen is continuously introduced, since nitrogen itself does not participate in the reaction inside the hydrogenation tower 1, prolonged nitrogen introduction will cause an increase in the internal gas pressure and nitrogen content of the system. Therefore, in this embodiment, the hydrogenation tail gas condensate metering tank 3 is provided with a tail gas discharge outlet, and a flow meter 16 and a regulating valve 17 are provided on the pipe connected to the tail gas discharge outlet. The flow meter 16 is used to measure the amount of tail gas discharged from the hydrogenation tail gas condensate metering tank 3, and the regulating valve 17 is used to control the amount of tail gas discharged from the hydrogenation tail gas condensate metering tank 3. When the pressure inside the system increases or the nitrogen content is too high, by opening the regulating valve 17, a portion of the tail gas can be discharged to reduce the internal pressure of the system and at the same time reduce the nitrogen content, thereby controlling the content of inert gas components in the hydrogenation tail gas condensate metering tank 3 and the hydrogenation tower 1.

[0044] In this embodiment, the hydrogen and nitrogen gas in the hydrogenation tail gas condensate metering tank 3 is compressed and pressurized by the hydrogen and nitrogen gas circulating compressor 4. To control the pressure of the compressed hydrogen and nitrogen gas, a bypass pipeline is provided between the inlet and outlet of the hydrogen and nitrogen gas circulating compressor 4, and a regulating valve 18 is provided on the bypass pipeline. A pressure transmitter 19 is provided on the pipeline connected to the outlet of the hydrogen and nitrogen gas circulating compressor 4. The pressure transmitter 19 is interlocked with the regulating valve 18. The pressure transmitter 19 can monitor the hydrogen and nitrogen gas pressure at the outlet of the hydrogen and nitrogen gas circulating compressor 4 and then control the opening of the regulating valve 18, thereby accurately controlling the flow rate of hydrogen and nitrogen gas to the inlet of the hydrogenation tower 1.

[0045] Preferably, in this embodiment, pressure transmitter 9, pressure transmitter 13, and pressure transmitter 19 are respectively connected to the distributed control system, and the output values ​​of pressure transmitters 9, 13, and 19 are respectively transmitted to the distributed control system; regulating valves 8, 10, 12, 14, 17, and 18 are respectively connected to the distributed control system, and their opening degrees are controlled by the distributed control system. It should be noted that the control connections between the devices in this embodiment can be adjusted according to actual production conditions.

[0046] Furthermore, in this system, the gas inside the hydrogenation tail gas condensate metering tank 3 is a mixture of hydrogen and nitrogen. Therefore, when the tail gas is discharged, some hydrogen will be released. To avoid hydrogen waste, this system also includes an aromatic hydrocarbon recovery device 6. The aromatic hydrocarbon recovery device 6 is equipped with a temperature-switching adsorption unit. The inlet of the aromatic hydrocarbon recovery device 6 is connected to the tail gas discharge outlet of the hydrogenation tail gas condensate metering tank 3, and the tail gas outlet of the aromatic hydrocarbon recovery device 6 is vented. The liquid outlet of the aromatic hydrocarbon recovery device 6 is connected to the aromatic hydrocarbon recovery system. The aromatic hydrocarbon recovery device 6 can treat the discharged tail gas, recover aromatic substances, render the tail gas harmless, and reduce emission pollution. The recovered aromatic substances are then recycled through the aromatic hydrocarbon recovery system.

[0047] It should be noted that in this embodiment, the regulating valve is preferably a pneumatic regulating valve with fault shut-off. By interlocking the regulating valve with the pressure transmitter, the gas flow can be automatically controlled to maintain pressure stability. Furthermore, in the event of an accident, the pneumatic regulating valve with fault shut-off will automatically cut off the corresponding regulating valve supplying hydrogen and nitrogen to ensure system safety. The flow meter is preferably a mass flow meter, which can provide both local and centralized display and has cumulative metering capabilities.

[0048] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, or alterations made by those skilled in the art using the disclosed technical content shall fall within the protection scope of the present invention.

Claims

1. A hydrogen-nitrogen gas circulation and self-cleaning system in a hydrogen peroxide production apparatus, characterized in that, include: A hydrogenation tower, the inlet of which is connected to the hydrogen outlet of the hydrogen production system, and the outlet of which is connected to the inlet of the hydrogenation tail gas cooler; A hydrogenation tail gas cooler, the outlet of which is connected to the first inlet of a hydrogenation tail gas condensate metering tank; A hydrogenation tail gas condensate metering tank is provided with a first outlet, a nitrogen inlet, a waste liquid discharge outlet and a tail gas emission outlet. The first outlet is connected to the inlet of a hydrogen-nitrogen circulation compressor, the nitrogen inlet is connected to the nitrogen outlet of a nitrogen generation system, the waste liquid discharge outlet is connected to a wastewater treatment system, and the tail gas emission outlet is connected to a tail gas treatment system. A hydrogen-nitrogen recirculating compressor, wherein the outlet of the hydrogen-nitrogen recirculating compressor is connected to the inlet of a hydrogen-nitrogen filter; A hydrogen-nitrogen filter, the outlet of which is connected to the pipeline between the inlet of the hydrogenation tower and the hydrogen outlet of the hydrogen production system; The pipeline connected to the nitrogen inlet of the hydrogenation tail gas condensate metering tank is equipped with a second flow meter and a third regulating valve. The second flow meter is used to measure the flow rate of nitrogen introduced into the hydrogenation tail gas condensate metering tank by the nitrogen generation system, and the third regulating valve is used to control the flow rate of nitrogen introduced into the hydrogenation tail gas condensate metering tank. The hydrogenation tail gas condensate metering tank is equipped with a second pressure transmitter, which is interlocked with the third regulating valve. The opening degree of the third regulating valve is controlled by monitoring the pressure change inside the hydrogenation tail gas condensate metering tank through the second pressure transmitter.

2. The hydrogen-nitrogen gas circulation and self-cleaning system in the hydrogen peroxide production apparatus according to claim 1, characterized in that, A first flow meter and a first regulating valve are installed on the pipeline between the inlet of the hydrogenation tower and the outlet of the hydrogen production system. The first flow meter is used to measure the flow rate of hydrogen from the hydrogen production system into the hydrogenation tower, and the first regulating valve is used to control the flow rate of hydrogen from the hydrogen production system into the hydrogenation tower. The first regulating valve is interlocked with the first flow meter, and the opening of the first regulating valve is adjusted by the output value of the first flow meter to control the flow rate of hydrogen entering the hydrogenation tower.

3. The hydrogen-nitrogen gas circulation and self-cleaning system in the hydrogen peroxide production apparatus according to claim 2, characterized in that, The hydrogenation tower is equipped with a first pressure transmitter, and the pipeline connected to the outlet of the hydrogenation tower is equipped with a second regulating valve. The second regulating valve is used to control and regulate the internal pressure of the hydrogenation tower. The first pressure transmitter is interlocked with the second regulating valve, and the opening degree of the second regulating valve is controlled by monitoring the internal pressure change of the hydrogenation tower through the first pressure transmitter.

4. The hydrogen-nitrogen gas circulation and self-cleaning system in the hydrogen peroxide production apparatus according to claim 3, characterized in that, A fourth regulating valve is installed on the pipeline connected to the waste liquid discharge outlet of the hydrogenation tail gas condensate metering tank. The fourth regulating valve is used to control the liquid discharge from the hydrogenation tail gas condensate metering tank and maintain a stable liquid level in the tank. A level gauge is installed on the hydrogenation tail gas condensate metering tank. The level gauge is interlocked with the fourth regulating valve. The opening degree of the fourth regulating valve is controlled by monitoring the change in the liquid level in the hydrogenation tail gas condensate metering tank through the level gauge.

5. The hydrogen-nitrogen gas circulation and self-cleaning system in the hydrogen peroxide production apparatus according to claim 4, characterized in that, The pipeline connected to the tail gas emission outlet of the hydrogenation tail gas condensate metering tank is equipped with a third flow meter and a fifth regulating valve. The third flow meter is used to measure the amount of hydrogenation tail gas emitted from the hydrogenation tail gas condensate metering tank, and the fifth regulating valve is used to control the amount of hydrogenation tail gas emitted from the hydrogenation tail gas condensate metering tank, thereby controlling the inert gas components in the hydrogenation tail gas condensate metering tank and the hydrogenation tower.

6. The hydrogen-nitrogen gas circulation and self-cleaning system in the hydrogen peroxide production apparatus according to claim 5, characterized in that, A bypass pipeline is provided between the inlet and outlet of the hydrogen-nitrogen circulating compressor, and a sixth regulating valve is provided on the bypass pipeline. The sixth regulating valve is used to control the hydrogen and nitrogen pressure in the hydrogen-nitrogen circulating compressor. A third pressure transmitter is provided on the pipeline connected to the outlet of the hydrogen-nitrogen circulating compressor. The third pressure transmitter is interlocked with the sixth regulating valve. The opening degree of the sixth regulating valve is controlled by monitoring the hydrogen and nitrogen pressure in the hydrogen-nitrogen circulating compressor through the third pressure transmitter.

7. The hydrogen-nitrogen gas circulation and self-cleaning system in the hydrogen peroxide production apparatus according to any one of claims 1-6, characterized in that, It also includes an aromatic hydrocarbon recovery device, which is equipped with a temperature-switching adsorption unit. The inlet of the aromatic hydrocarbon recovery device is connected to the tail gas emission outlet of the hydrogenation tail gas condensate metering tank, the tail gas outlet of the aromatic hydrocarbon recovery device is vented, and the liquid outlet of the aromatic hydrocarbon recovery device is connected to the aromatic hydrocarbon recovery system.

8. The hydrogen-nitrogen gas circulation and self-cleaning system in the hydrogen peroxide production apparatus according to claim 6, characterized in that, The first, second, third, fourth, fifth, and sixth regulating valves are all pneumatic switching valves; the first flow meter, the first flow meter, and the third flow meter are all mass flow meters.

9. The hydrogen-nitrogen gas circulation and self-cleaning system in the hydrogen peroxide production apparatus according to claim 6, characterized in that, It also includes a distributed control system. The first flow meter, the third flow meter, and the fourth flow meter are respectively connected to the distributed control system to realize on-site and centralized display and have cumulative metering function. The first pressure transmitter, the second pressure transmitter, and the third pressure transmitter are respectively connected to the distributed control system, and the output values ​​of the first pressure transmitter, the second pressure transmitter, and the third pressure transmitter are respectively transmitted to the distributed control system. The first regulating valve, the second regulating valve, the third regulating valve, the fourth regulating valve, the fifth regulating valve, and the sixth regulating valve are respectively connected to the distributed control system and the opening degree is controlled by the distributed control system.

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