Regeneration system for hydrogen peroxide fixed bed catalyst air

Abstract

The utility model provides a regeneration system for hydrogen peroxide fixed bed catalyst air, which is characterized in that a first main pipeline is used for introducing air, nitrogen, steam and desalted water into an upper tower of a hydrogenation tower, and a second main pipeline is used for introducing a working solution and aromatic hydrocarbon; the cooler is used for cooling the steam condensate; the hydrogenation tower regeneration steam condensate pipeline is used for communicating an inlet of the cooler with the hydrogenation tower upper tower, the hydrogenation tower middle tower and the hydrogenation tower lower tower respectively; the separator is used for separating tail gas in the condensate from the condensate or aromatic hydrocarbon; and the aromatic hydrocarbon reflux pipeline is used for introducing the aromatic hydrocarbon separated by the separator into the aromatic hydrocarbon pipeline for cyclic utilization. Organic impurities adsorbed by a catalyst in a hydrogenation tower are fully dissolved and washed away by using an aromatic hydrocarbon solvent, air is added to oxidize the catalyst for regeneration, and part of reducing substances adsorbed by the catalyst are oxidized and dissolved by the aromatic hydrocarbon solvent, so that the catalyst is deeply regenerated, a better catalyst regeneration effect is achieved, and the service life of the catalyst is prolonged. The product energy consumption is reduced.

Description

Technical Field

[0001] This utility model relates to the field of hydrogen peroxide production technology, and in particular to a hydrogen peroxide fixed-bed catalyst air regeneration system. Background Technology

[0002] The anthraquinone process for producing hydrogen peroxide uses a fixed-bed hydrogenation method with a palladium catalyst. After a period of use during hydrogenation, the activity of the palladium catalyst gradually decreases. When the conditions required for the catalyst to promote the reaction have reached a certain level, but the catalyst activity still cannot meet the minimum production requirements, the catalyst needs to be regenerated. Typically, fixed-bed palladium catalyst regeneration uses a steam purging method: after shutdown, the working fluid in the fixed bed is purged with nitrogen, and then saturated steam is used to dissolve and rinse away organic and inorganic salt impurities adsorbed on the palladium catalyst until the condensate is clear and transparent, at which point regeneration stops. Finally, nitrogen is used to circulate and dry the catalyst in the bed. This method is effective for catalyst regeneration in the early stages of the catalyst bed. However, as the catalyst's service life increases, the amount of organic impurities adsorbed deep within the catalyst micropores increases, and the steam regeneration method alone cannot deeply clean the adsorbed organic impurities within the catalyst, failing to achieve the desired regeneration effect. The regenerated catalyst not only has a short service life and high regeneration steam consumption, but also results in low production capacity and increased production costs in subsequent production due to insufficient catalyst activity. Utility Model Content

[0003] The purpose of this utility model embodiment is to provide a hydrogen peroxide fixed bed catalyst air regeneration system.

[0004] The embodiments of this utility model adopt the following technical solution: a hydrogen peroxide fixed-bed catalyst air regeneration system, applied to a hydrogenation tower, the hydrogenation tower including an upper hydrogenation tower, a middle hydrogenation tower, and a lower hydrogenation tower, the regeneration system including:

[0005] The first main pipeline is used to connect the air pipeline, nitrogen pipeline, steam pipeline and demineralized water pipeline to the upper tower of the hydrogenation tower, and to introduce air, nitrogen, steam and demineralized water into the upper tower of the hydrogenation tower for purging, steam regeneration and temperature and pressure control of the hydrogenation tower.

[0006] The second main pipeline is connected to the upper tower of the hydrogenation tower and is used for the introduction of working fluid and aromatics.

[0007] A cooler, used to cool condensed steam;

[0008] The hydrogenation tower regenerated steam condensate pipeline is used to connect the inlet of the cooler to the upper, middle and lower sections of the hydrogenation tower, respectively.

[0009] A separator connected to the outlet of the cooler to receive the condensate of steam cooled by the cooler and to separate the tail gas from the condensate or aromatics.

[0010] An aromatics pipeline, equipped with a circulation pump, is used to supply aromatics to the lower column of the hydrogenation tower and to circulate them to the upper and middle columns of the hydrogenation tower for aromatics circulation cleaning, thereby achieving catalyst regeneration. Furthermore, when air is supplied to the upper column of the hydrogenation tower via the air pipeline, catalyst regeneration and air oxidation catalyst regeneration are performed. Connecting pipelines and control valves are respectively installed between the upper and lower columns of the hydrogenation tower, and between the middle and lower columns of the hydrogenation tower.

[0011] An aromatics reflux line connects the separator and the aromatics pipeline to circulate the aromatics separated by the separator into the aromatics pipeline.

[0012] In some embodiments, an air valve is provided on the air pipeline.

[0013] A nitrogen valve is installed on the nitrogen pipeline.

[0014] A steam valve is installed on the steam pipeline.

[0015] A demineralized water valve is installed on the demineralized water pipeline;

[0016] The air valve, nitrogen valve, steam valve, and demineralized water valve can be opened and closed respectively.

[0017] In some embodiments, the connecting pipeline between the upper hydrogenation tower and the middle hydrogenation tower is equipped with a working liquid discharge valve for the upper hydrogenation tower and a working liquid inlet valve for the middle hydrogenation tower. When the working liquid discharge valve for the upper hydrogenation tower and the working liquid inlet valve for the middle hydrogenation tower are open, the material in the upper hydrogenation tower can enter the middle hydrogenation tower, thereby realizing the connection between the upper hydrogenation tower and the middle hydrogenation tower.

[0018] In some embodiments, a discharge pipeline is provided at the bottom of the lower column of the hydrogenation tower, and a discharge valve for the lower column of the hydrogenation tower is provided on the discharge pipeline. The aromatics pipeline includes a replenishing aromatics pipeline, a circulating aromatics pipeline, and a circulating pump feed pipeline connected in sequence. When the discharge valve for the lower column of the hydrogenation tower is open, the aromatics can enter the lower column of the hydrogenation tower through the replenishing aromatics pipeline, the circulating aromatics pipeline, and the discharge pipeline of the lower column of the hydrogenation tower. The aromatics can also enter the upper column of the hydrogenation tower through the replenishing aromatics pipeline, the circulating aromatics pipeline, and the circulating pump feed pipeline, and then enter the middle column of the hydrogenation tower through the connecting pipeline between the upper column of the hydrogenation tower and the middle column of the hydrogenation tower.

[0019] In some embodiments, a circulation regulating valve is provided on the feed line of the circulation pump to regulate the circulation rate of the aromatics.

[0020] In some embodiments, the separator is also connected to a tail gas venting pipeline, which is equipped with a tail gas venting regulating valve. When the tail gas venting regulating valve is open, it can control the pressure inside the hydrogenation tower.

[0021] In some embodiments, an upper tower regenerated hydrogen condensate valve is provided on the hydrogenation tower regeneration steam condensate pipeline connected to the upper tower of the hydrogenation tower, and a middle tower regenerated hydrogen condensate valve is provided on the hydrogenation tower regeneration steam condensate pipeline connected to the middle tower of the hydrogenation tower.

[0022] In some embodiments, the regeneration system further includes a discharge line equipped with a recovery valve, the discharge line being used to connect the outlet of the separator to the recovery system, so as to transport the condensate and aromatics separated by the separator to the recovery system.

[0023] The beneficial effects of this utility model embodiment are as follows:

[0024] The organic impurities adsorbed on the catalyst in the hydrogenation tower are thoroughly dissolved and rinsed with an aromatic solvent. Then, air oxidation is introduced for catalyst regeneration. This process oxidizes some of the reducing substances adsorbed on the catalyst, which are then dissolved by the aromatic solvent. This deep regeneration of the catalyst restores its activity, achieving better regeneration results and extending its service life. The catalyst regenerated using air oxidation exhibits better hydrogenation catalytic activity, and under the same operating conditions, it has a longer service life, which is beneficial for long-term, stable, and high-yield production of hydrogen peroxide while reducing energy consumption. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a structural block diagram of the hydrogen peroxide fixed-bed catalyst air regeneration system of this utility model.

[0027] Attached reference numerals: 1. Air valve; 2. Nitrogen valve; 3. Steam valve; 4. Demineralized water valve; 5. Second main pipeline; 6. Upper hydrogenation tower working liquid feed valve; 7. Upper hydrogenation tower working liquid discharge valve; 8. Upper hydrogenation tower regeneration steam condensate valve; 9. Middle hydrogenation tower working liquid feed valve; 10. Middle hydrogenation tower working liquid discharge valve; 11. Middle hydrogenation tower regeneration steam condensate valve; 12. Aromatics replenishment valve; 13. Lower hydrogenation tower discharge valve; 14. Circulation 15. Control valve; 16. Recovery valve; 17. Aromatics recirculation valve; 18. Tail gas venting control valve; 29. ​​Flow meter; 20. Circulation pump; 21. Hydrogenation tower; 22. Upper hydrogenation tower; 23. Middle hydrogenation tower; 24. Lower hydrogenation tower; 25. Cooler; 26. Separator; 37. First main pipeline; 38. Aromatics replenishment pipeline; 39. Circulation aromatics pipeline; 30. Circulation pump feed pipeline; 31. Discharge pipeline; 32. Tail gas venting pipeline. Detailed Implementation

[0028] Various embodiments and features of this application are described herein with reference to the accompanying drawings.

[0029] It should be understood that various modifications can be made to the embodiments described herein. Therefore, the above description should not be considered as limiting, but merely as an example of embodiments. Other modifications within the scope and spirit of this application will be apparent to those skilled in the art.

[0030] The accompanying drawings, which are included in and form part of this specification, illustrate embodiments of the present application and, together with the general description of the present application given above and the detailed description of the embodiments given below, serve to explain the principles of the present application.

[0031] These and other features of this application will become apparent from the following description of preferred forms of embodiments given as non-limiting examples, with reference to the accompanying drawings.

[0032] It should also be understood that although this application has been described with reference to some specific examples, those skilled in the art can certainly implement many other equivalent forms of this application.

[0033] The above and other aspects, features and advantages of this application will become more apparent when taken in conjunction with the accompanying drawings and in view of the following detailed description.

[0034] Specific embodiments of this application are described thereafter with reference to the accompanying drawings; however, it should be understood that the claimed embodiments are merely examples of this application, which can be implemented in various ways. Well-known and / or repeated functions and structures are not described in detail to avoid unnecessary or redundant details that could obscure the application. Therefore, the specific structural and functional details claimed herein are not intended to be limiting, but merely serve as the basis and representative basis for the claims to teach those skilled in the art to use this application in a variety of substantially any suitable detailed structures.

[0035] This specification may use the phrases “in one embodiment,” “in another embodiment,” “in yet another embodiment,” or “in other embodiments,” all of which may refer to one or more of the same or different embodiments according to this application.

[0036] To address the problems in the background technology, this utility model provides a hydrogen peroxide fixed-bed catalyst air regeneration system, applied to a hydrogenation tower. The hydrogenation tower 26 includes an upper hydrogenation tower 261, a middle hydrogenation tower 262, and a lower hydrogenation tower 263. Combined with... Figure 1 The regeneration system includes:

[0037] This invention provides a hydrogen peroxide fixed-bed catalyst air regeneration system applied to a hydrogenation tower, which includes an upper hydrogenation tower 261, a middle hydrogenation tower 262, and a lower hydrogenation tower 263. Combined with... Figure 1 The regeneration system includes:

[0038] The first main pipeline 31 connects the air pipeline, nitrogen pipeline, steam pipeline, and demineralized water pipeline to the upper column 261 of the hydrogenation tower, and introduces air, nitrogen, steam, and demineralized water into the upper column 261 for purging, steam regeneration, and temperature and pressure control. The upper column 261 of the hydrogenation tower can be regenerated independently, or it can be connected in series with the middle column 262 of the hydrogenation tower for steam regeneration, aromatics circulation cleaning, or aromatics circulation + air circulation regeneration.

[0039] The second main pipeline 5 is connected to the upper tower 261 of the hydrogenation tower and is used for the introduction of working fluid and aromatics.

[0040] Cooler 27 is used to cool the vapor condensate. The circulating liquid temperature is controlled by cooler 27, the maximum flow rate is used to establish the aromatics cycle, and nitrogen is used to maintain the tower pressure.

[0041] The regenerated steam condensate pipeline of the hydrogenation tower is used to connect the inlet of the cooler 27 to the upper tower 261, the middle tower 262 and the lower tower 263 of the hydrogenation tower respectively, so as to pass the steam condensate of the hydrogenation tower into the cooler 27 for cooling treatment.

[0042] The separator 28 is connected to the outlet of the cooler 27 to receive the steam condensate cooled by the cooler 27, and separates the tail gas in the condensate from the condensate or aromatics, and then discharges it into the unit's oil separator or recovery system through the discharge pipeline 35.

[0043] An aromatics pipeline, equipped with a circulation pump 20, is used to supply aromatics to the lower column 263 of the hydrogenation tower and to circulate them to the upper column 261 and the middle column 262 of the hydrogenation tower via the circulation pump 20. This process cleans the hydrogenation towers with aromatics, thereby regenerating the catalyst. Furthermore, when air is supplied to the upper column 261 of the hydrogenation tower via the air pipeline, catalyst regeneration and air oxidation catalyst regeneration are performed. Connecting pipelines and control valves are installed between the upper column 261 and the lower column 263 of the hydrogenation tower, and between the middle column 262 and the lower column 263 of the hydrogenation tower. When the control valves are open, the connection between the different hydrogenation towers can be controlled; when the control valves are closed, the connection between the hydrogenation towers can be disconnected.

[0044] The aromatics reflux pipeline connects to the separator 28 and the aromatics pipeline, allowing the aromatics separated by the separator 28 to be circulated into the aromatics pipeline for cleaning of the hydrogenation tower. The aromatics solvent is used to fully dissolve and rinse away the organic impurities adsorbed on the catalyst. Then, air oxidation is introduced to regenerate the catalyst, oxidizing some of the reducing substances adsorbed on the catalyst and dissolving them in the aromatics solvent. This allows for deep regeneration of the catalyst, restoring its activity and achieving better catalyst regeneration, thereby extending the catalyst's service life.

[0045] This regeneration system can achieve steam regeneration of the catalyst in the upper column 261 of the hydrogenation tower, steam regeneration of the catalyst in the upper column 261 and the middle column 262 of the hydrogenation tower connected in series, aromatics circulation cleaning of the catalyst in the upper column 261 and the middle column 262 of the hydrogenation tower connected in series, and aromatics circulation + air circulation regeneration of the catalyst in the upper column 261 and the middle column 262 of the hydrogenation tower connected in series, thus completing the deep regeneration of the catalyst.

[0046] Aromatics can use, but are not limited to, C 10 Aromatics are used for circulating cleaning. C can be used. 10 While the aromatics are being circulated and cleaned, air is added for oxidation.

[0047] An air valve 1 is installed on the air line, a nitrogen valve 2 is installed on the nitrogen line, a steam valve 3 is installed on the steam line, and a demineralized water valve 4 is installed on the demineralized water line. Air valve 1, nitrogen valve 2, steam valve 3, and demineralized water valve 4 can be opened and closed independently. That is, air, nitrogen, steam, and demineralized water can be introduced into the hydrogenation tower individually, or any two or more of these gases can be introduced into the hydrogenation tower simultaneously.

[0048] The connecting pipeline between the upper hydrogenation tower 261 and the middle hydrogenation tower 262 is equipped with a working liquid discharge valve 7 for the upper hydrogenation tower and a working liquid inlet valve 9 for the middle hydrogenation tower. When the working liquid discharge valve 7 for the upper hydrogenation tower and the working liquid inlet valve 9 for the middle hydrogenation tower 262 are open, the material in the upper hydrogenation tower 261 can enter the middle hydrogenation tower 262, thereby realizing the connection between the upper hydrogenation tower 261 and the middle hydrogenation tower 262.

[0049] A discharge pipeline is installed at the bottom of the lower column 263 of the hydrogenation tower, and a discharge valve 13 is installed on the discharge pipeline. The aromatics pipeline includes a feed aromatics pipeline 32, a circulating aromatics pipeline 33, and a circulating pump feed pipeline 34 connected in sequence. When the discharge valve 13 of the lower column is open, aromatics can enter the lower column 263 of the hydrogenation tower via the feed aromatics pipeline 32, the circulating aromatics pipeline 33, and the discharge pipeline of the lower column 263 of the hydrogenation tower. The flow stops when the required liquid level is reached. Aromatics can also enter the upper column 261 of the hydrogenation tower via the feed aromatics pipeline 32, the circulating aromatics pipeline 33, and the feed pipeline of the circulating pump 20, and then enter the middle column 262 of the hydrogenation tower via the connecting pipeline between the upper column 261 and the middle column 262 of the hydrogenation tower.

[0050] A circulation regulating valve 14 can be installed on the feed line of the circulating pump 20 to regulate the circulation volume of aromatics. A flow meter 18 can also be installed on the feed line of the circulating pump 20 to detect the flow rate of aromatics on the feed line of the circulating pump 20, so as to more accurately control the amount of aromatics fed into the hydrogenation tower.

[0051] The separator 28 can also be connected to the exhaust gas venting line 36, which is equipped with an exhaust gas venting regulating valve 17. When the exhaust gas venting regulating valve 17 is open, it can control the pressure inside the hydrogenation tower.

[0052] A regenerated hydrogen condensate valve is installed on the regenerated steam condensate pipeline connected to the upper hydrogenation tower 261, and a regenerated hydrogen condensate valve is installed on the regenerated steam condensate pipeline connected to the middle hydrogenation tower 262. The upper and middle regenerated hydrogen condensate valves can be opened separately as needed to discharge the condensate from the upper hydrogenation tower 261, or the condensate from both the upper and middle hydrogenation towers 261 and 262.

[0053] The regeneration system also includes an exhaust line 35, on which a recovery valve 15 is installed. The exhaust line 35 is used to connect the outlet of the separator 28 and the recovery system so as to deliver the condensate and aromatics separated by the separator 28 to the recovery system when aromatics recycling is not required.

[0054] As one embodiment, catalyst regeneration can be performed during system shutdown. For example, firstly, a steam regeneration step for the upper hydrogenation tower 261 is established and implemented: after the working liquid in the hydrogenation tower is drained, the inlet / outlet valves of the upper hydrogenation tower 261 are closed, and then the steam regeneration process for the upper hydrogenation tower 261 begins. Specifically, steam valve 3 of the upper hydrogenation tower 261 can be opened to gradually introduce steam into the upper hydrogenation tower 261, while simultaneously, demineralized water valve 4 is opened to appropriately introduce demineralized water into the steam. The steam and demineralized water flow rates are gradually adjusted according to the temperature inside the upper hydrogenation tower 261 and the pressure at the top of the tower. The steam and condensate are discharged from the upper hydrogenation tower regeneration steam condensate valve 8 to the cooler 27, cooled by the cooler 27 and separated by the separator 28, and then discharged into the unit's oil separator or recovery system via the discharge pipeline 35.

[0055] Specifically, the steam flow rate is gradually increased to about 3.5 t / h in the upper tower 261 of the hydrogenation tower through the first main pipeline 31. At the same time, the demineralized water pipeline valve is opened to introduce about 1.5 t / h of demineralized water into the steam, and the temperature inside the upper tower 261 of the hydrogenation tower is controlled at about 120℃ to 122℃, and the pressure at the top of the tower is about 0.09 MPa.

[0056] Steam and condensate in the upper column 261 of the hydrogenation tower are cooled and separated by the regeneration steam condensate valve 8 of the upper column of the hydrogenation tower, through the cooler 27 and the separator, and then discharged into the unit's recovery system through the recovery valve 15 on the discharge pipeline 35. The steam purging time of the upper column 261 of the hydrogenation tower is 8 hours, and the steam purging condensate is basically clean.

[0057] When implementing series steam regeneration of the upper hydrogenation tower 261 and the middle hydrogenation tower 262, steam valve 3 can be opened to introduce steam into the upper hydrogenation tower 261. After the upper hydrogenation tower 261 is purged with steam for a period of time (depending on the cleanliness of the discharged condensate), the steam purging of the upper hydrogenation tower 261 continues. The demineralized water valve 4 can also be opened to maintain an appropriate amount of demineralized water added to the steam. The working liquid discharge valve 10 of the middle hydrogenation tower on the connecting pipeline between the middle hydrogenation tower 262 and the lower hydrogenation tower 263 is closed, and the working liquid discharge valve 7 of the upper hydrogenation tower on the connecting pipeline between the upper hydrogenation tower 261 and the middle hydrogenation tower 262 is opened, completing the series connection of the upper hydrogenation tower 261 and the middle hydrogenation tower 262 and opening the series steam regeneration process between them. Simultaneously, the regeneration steam condensate valve 11 of the middle hydrogenation tower is opened, and the regeneration steam condensate valve 8 of the upper hydrogenation tower is closed. Continue to introduce steam and demineralized water into the upper column 261 of the hydrogenation tower, and control the steam regeneration temperature in the upper column 261 and the middle column 262 of the hydrogenation tower within the required range until the condensate is basically clear and clean.

[0058] Specifically, after the steam purging of the upper tower 261 of the hydrogenation tower is completed, continue purging with approximately 3.5 t / h of steam and add an appropriate amount of pure water (approximately 1.5 t / h) to the steam. Establish a series steam regeneration process between the upper tower 261 and the middle tower 262 of the hydrogenation tower. Control the steam regeneration temperature in both towers 261 and 262 at 120℃ to 122℃, and maintain a tower top pressure of approximately 0.09 MPa. Maintain the series steam purging time for 16 hours until the condensate is basically clear and clean.

[0059] During the series-connected aromatics circulation purging of the upper hydrogenation tower 261 and the middle hydrogenation tower 262, the working fluid in the lower hydrogenation tower 263 and the feed pipeline can be emptied during the steam purging of the upper hydrogenation tower 261 and the middle hydrogenation tower 262. The aromatics replenishment valve 12 and the lower hydrogenation tower discharge valve 13 on the aromatics pipeline can be opened to introduce aromatics from the aromatics recovery tank into the lower hydrogenation tower 263 until the required liquid level is reached, at which point the process can be stopped. After the series-connected steam purging of the upper hydrogenation tower 261 and the middle hydrogenation tower 262 is completed, the recovery valve 15 can be closed. Start circulating pump 20 to establish aromatics circulation. Open the inlet and outlet valves of circulating pump 20, circulating regulating valve 14, upper hydrogenation tower working liquid feed valve 6, and aromatics circulation valve 16. Check that the upper hydrogenation tower working liquid discharge valve 7, the middle hydrogenation tower 262 working liquid feed valve 9, and the middle hydrogenation tower 262 steam condensate valve are all open. Establish aromatics flushing circulation (circulating pump 20 → upper hydrogenation tower 261 → middle hydrogenation tower 262 → cooler 27 → separator 28 → circulating pump 20). Control the circulating liquid temperature through cooler 27 to establish aromatics circulation at maximum flow rate, and maintain tower pressure with nitrogen. After the upper hydrogenation tower 261 and middle hydrogenation tower 262 have been flushed in series for a period of time, stop circulating pump 20. Transfer the flushed aromatics from the lower hydrogenation tower 263 to other storage tanks in the unit and analyze the flushed aromatics components. Reintroduce C from the aromatics storage tank into the lower hydrogenation tower 263. 10 A certain amount of aromatic raw materials are used, and then the circulation pump 20 is restarted to establish aromatic circulation and cleaning, requiring the circulation temperature to be between 50℃ and 55℃.

[0060] Specifically, during the steam purging of the hydrogenation tower, the working fluid in the lower tower 263 and the feed pipeline of the hydrogenation tower is emptied, and approximately 40m³ of aromatics are transferred to the lower tower 263 of the hydrogenation tower for system recovery. 3 After the upper hydrogenation tower 261 and the middle hydrogenation tower 262 are purged with steam in series, the circulating pump 20 is started to establish an aromatics cycle (upper hydrogenation tower 261 → middle hydrogenation tower 262 → cooler 27 → separator 28 → circulating pump 20). The circulating liquid temperature is controlled at approximately 80°C by the cooler 27, and the maximum flow rate is used to establish an aromatics cycle of 160m³. 3 / h, nitrogen is added at the top of the column to maintain the column pressure at 0.15MPa. After 5 hours of series aromatics circulation in the upper column 261 and the middle column 262 of the hydrogenation column, the circulation pump 20 is stopped, and the cleaned aromatics in the lower column 263 of the hydrogenation column are transferred to other storage tanks in the unit. The components of the cleaned aromatics are analyzed: total anthraquinone content 119g / L, hydrogen efficiency 2.6g / L. C is then introduced back into the lower column 263 of the hydrogenation column. 10 Raw material aromatics 32m 3 Restart the circulation pump 20 to establish circulation, control the temperature of the circulating aromatics to about 52°C, and continue circulation for 5 hours. Take a sample to analyze the circulating aromatics: total anthraquinone content 18 g / L, hydrogen efficiency 2.4 g / L.

[0061] When implementing the series regeneration of the catalyst in the upper and middle towers of the hydrogenation tower using aromatics circulation and air circulation, continue the aromatics circulation. Open air valve 1 to introduce air into the top of the upper tower 261 of the hydrogenation tower, and simultaneously open nitrogen valve 2 to supplement nitrogen. Open the tail gas vent regulating valve 17 to automatically control the pressure inside the hydrogenation tower and maintain it within a certain pressure range. During the aerobic circulation process, pay attention to the temperature changes in the hydrogenation tower. Control the circulating liquid temperature through cooler 27, ensuring the circulation temperature remains within a certain range. If the hydrogenation tower temperature exceeds the required maximum temperature, close air valve 1 to stop adding air, but continue nitrogen circulation for purging. During the air and aromatics circulation process in the hydrogenation tower, analyze the oxygen content of the tail gas every hour and perform hydrogen efficiency analysis of the circulating liquid every 2 hours, recording the regeneration process. Gradually increase the air-nitrogen ratio until only air is used, then stop using nitrogen. When the circulating liquid hydrogen efficiency is ≤0.20g / L and the oxygen content of the exhaust gas is ≥20%, the regeneration of the air oxidation catalyst in the hydrogenation tower is complete. Close the air inlet valve 1 at the top of the hydrogenation tower (261), and increase the nitrogen supply until the tower tail is vented and the replacement is qualified.

[0062] Specifically, continue circulating the aromatics using the 20-pump circulation system, drawing approximately 200m³ of air. 3 / h is introduced into the top of column 261 of the hydrogenation tower, and nitrogen 200m is added simultaneously. 3 At 1 hour, the tower pressure is automatically controlled to 0.15 MPa by opening the tail vent regulating valve. During the aerobic circulation process, the hydrogenation tower temperature rises slightly (approximately 0.5℃ / h to 1.0℃ / h). The circulating liquid temperature is controlled at 52℃ to 53℃ by cooling water in cooler 27 for 4 hours. During the air + aromatics circulation process in the hydrogenation tower, the oxygen content of the tail gas is analyzed hourly, and the hydrogen efficiency of the circulating liquid is measured every 2 hours. In the initial 4 hours, the oxygen content of the tail gas is ≤0.4%, and the hydrogen efficiency is between 2.0 g / L and 2.4 g / L. During the air oxidation catalyst regeneration process, the air-nitrogen ratio is gradually increased (up to 200 m³ / h). 3 / h), until all air is used for approximately 300m 3 / h and nitrogen gas was stopped. The hydrogen efficiency of the circulating liquid was analyzed and gradually decreased. In the last 2 hours, the hydrogen efficiency of the circulating liquid was continuously analyzed to be ≤0.18g / L, and the oxygen content of the exhaust gas was ≥20.4%. The regeneration of the air oxidation catalyst in the hydrogenation tower was completed.

[0063] Regeneration effect verification:

[0064] Before catalyst shutdown and regeneration, the hydrogen production load of the hydrogenation tower must be maintained at 4850 Nm. 3 At 10:00 h, the working fluid inlet temperature reached 48℃, the hydrogenation tower was shut down for nitrogen pressurization, and the top pressure of the upper column 261 of the hydrogenation tower reached 0.36 MPa. The catalyst activity could not meet the high-load production requirements, and the catalyst outlet temperature of the middle column 262 of the hydrogenation tower reached ≥67℃. After catalyst shutdown and regeneration, the system was restarted and resumed normal production, meeting the hydrogen production load of 4880 Nm³ for the hydrogenation tower. 3 The working fluid inlet temperature is controlled at 36℃ per hour, and the hydrogenation tower requires approximately 150 Nm³ of nitrogen to be replenished. 3 To suppress excessively high catalytic activity, the top pressure of the upper column 261 of the hydrogenation tower was controlled to ≤0.28MPa, and the catalyst outlet temperature of the middle column 262 of the hydrogenation tower was reduced to about 55℃. The catalyst activity was basically consistent with that of the new catalyst, and the catalyst regeneration achieved satisfactory regeneration results.

[0065] The foregoing has described in detail several embodiments of the present utility model, but the present utility model is not limited to these specific embodiments. Those skilled in the art can make various variations and modifications based on the concept of the present utility model, and these variations and modifications should all fall within the scope of protection claimed by the present utility model.

Claims

1. A hydrogen peroxide fixed-bed catalyst air regeneration system, characterized in that, It is applied to a hydrogenation tower, which includes an upper hydrogenation tower, a middle hydrogenation tower, and a lower hydrogenation tower. The regeneration system includes: The first main pipeline is used to connect the air pipeline, nitrogen pipeline, steam pipeline and demineralized water pipeline to the upper tower of the hydrogenation tower, and to introduce air, nitrogen, steam and demineralized water into the upper tower of the hydrogenation tower for purging, steam regeneration and temperature and pressure control of the hydrogenation tower. The second main pipeline is connected to the upper tower of the hydrogenation tower and is used for the introduction of working fluid and aromatics. A cooler, used to cool condensed steam; The hydrogenation tower regenerated steam condensate pipeline is used to connect the inlet of the cooler to the upper, middle and lower sections of the hydrogenation tower, respectively. A separator connected to the outlet of the cooler to receive the condensate of steam cooled by the cooler and to separate the tail gas from the condensate or aromatics. An aromatics pipeline, equipped with a circulation pump, is used to supply aromatics to the lower column of the hydrogenation tower and to circulate them to the upper and middle columns of the hydrogenation tower for aromatics circulation cleaning, thereby achieving catalyst regeneration. Furthermore, when air is supplied to the upper column of the hydrogenation tower via the air pipeline, catalyst regeneration and air oxidation catalyst regeneration are performed. Connecting pipelines and control valves are respectively installed between the upper and lower columns of the hydrogenation tower, and between the middle and lower columns of the hydrogenation tower. An aromatics reflux line connects the separator and the aromatics pipeline to circulate the aromatics separated by the separator into the aromatics pipeline.

2. The hydrogen peroxide fixed-bed catalyst air regeneration system according to claim 1, characterized in that, An air valve is installed on the air pipeline. A nitrogen valve is installed on the nitrogen pipeline. A steam valve is installed on the steam pipeline. A demineralized water valve is installed on the demineralized water pipeline; The air valve, nitrogen valve, steam valve, and demineralized water valve can be opened and closed respectively.

3. The hydrogen peroxide fixed-bed catalyst air regeneration system according to claim 1, characterized in that, The connecting pipeline between the upper and middle sections of the hydrogenation tower is equipped with a discharge valve for the upper section of the hydrogenation tower and a feed valve for the middle section of the hydrogenation tower. When the discharge valve for the upper section of the hydrogenation tower and the feed valve for the middle section of the hydrogenation tower are open, the material in the upper section of the hydrogenation tower can enter the middle section of the hydrogenation tower, thereby achieving communication between the upper and middle sections of the hydrogenation tower.

4. The hydrogen peroxide fixed-bed catalyst air regeneration system according to claim 1, characterized in that, A discharge pipeline is provided at the bottom of the lower tower of the hydrogenation tower, and a discharge valve for the lower tower of the hydrogenation tower is provided on the discharge pipeline. The aromatics pipeline includes a replenishing aromatics pipeline, a circulating aromatics pipeline, and a circulating pump feed pipeline connected in sequence. When the discharge valve for the lower tower of the hydrogenation tower is open, the aromatics can enter the lower tower of the hydrogenation tower through the replenishing aromatics pipeline, the circulating aromatics pipeline, and the discharge pipeline for the lower tower of the hydrogenation tower. The aromatics can enter the upper tower of the hydrogenation tower via the aromatics replenishment pipeline, the circulating aromatics pipeline, and the circulating pump feed pipeline, and then enter the middle tower of the hydrogenation tower via the connecting pipeline between the upper tower and the middle tower.

5. The hydrogen peroxide fixed-bed catalyst air regeneration system according to claim 4, characterized in that, A circulation regulating valve is installed on the feed line of the circulation pump to regulate the circulation rate of the aromatics.

6. The hydrogen peroxide fixed-bed catalyst air regeneration system according to claim 1, characterized in that, The separator is also connected to a tail gas venting pipeline, which is equipped with a tail gas venting regulating valve. When the tail gas venting regulating valve is open, it can control the pressure inside the hydrogenation tower.

7. The hydrogen peroxide fixed-bed catalyst air regeneration system according to claim 1, characterized in that, An upper tower regenerated hydrogen condensate valve is installed on the hydrogenation tower regeneration steam condensate pipeline connected to the upper tower of the hydrogenation tower, and a middle tower regenerated hydrogen condensate valve is installed on the hydrogenation tower regeneration steam condensate pipeline connected to the middle tower of the hydrogenation tower.

8. The hydrogen peroxide fixed-bed catalyst air regeneration system according to claim 1, characterized in that, The regeneration system also includes a discharge pipeline equipped with a recovery valve. The discharge pipeline is used to connect the outlet of the separator to the recovery system, so as to transport the condensate and aromatics separated by the separator to the recovery system.

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