Fluidized bed hydrogenation device for producing hydrogen peroxide by anthraquinone method

Abstract

The application discloses a fluidized bed hydrogenation device for hydrogen peroxide production by an anthraquinone method, which comprises a circulating working liquid tank, a circulating working liquid pump, a circulating working liquid cooler, a cut-off valve, a circulating working liquid buffer tank, a fluidized bed hydrogenation tower and a hydrogen pipeline, wherein the fluidized bed hydrogenation tower is provided with a gas distributor and a liquid distributor; the circulating working liquid from the circulating working liquid tank enters the fluidized bed hydrogenation tower through the liquid distributor after passing through the circulating working liquid pump, the circulating working liquid cooler, the cut-off valve and the circulating working liquid buffer tank, and the hydrogen pipeline is connected with the gas distributor; and the circulating working liquid buffer tank is provided with a coalescence filter element and a separation filter element. The fluidized bed hydrogenation device can eliminate the influence of free water on the hydrogenation reaction, uses a liquid to blow the tower bottom, greatly reduces the deposition of the catalyst, avoids using gas to directly blow the tower bottom, greatly reduces bubble coalescence, promotes the mass transfer of the gas-liquid two phases, and can improve the hydrogenation efficiency while reducing the gas circulation amount.

Description

Technical Field

[0001] This invention belongs to the field of anthraquinone process for producing hydrogen peroxide, and specifically relates to a fluidized bed hydrogenation device for producing hydrogen peroxide using the anthraquinone process. Background Technology

[0002] Hydrogen peroxide is a green oxidant with wide applications in the chemical industry. Currently, industrially, hydrogen peroxide is generally produced using the anthraquinone process. In this process, 2-ethylanthraquinone, 2-butylanthraquinone, 2-pentylanthraquinone, or mixtures thereof are typically used as a carrier, and a mixture of heavy aromatics, trioctyl phosphate, o-methylcyclohexyl acetate, tetrabutylurea, or diisobutylmethanol is used as a solvent. The carrier and solvent are combined in a specific ratio to form the working solution. The working solution circulates in the system in the order of hydrogenation, oxidation, extraction, and post-treatment, producing hydrogen peroxide. In the hydrogenation step, the working solution undergoes a hydrogenation reaction under the action of a catalyst to obtain a hydrogenated solution. In the oxidation step, the hydrogenated solution reacts with oxygen to obtain an oxidized solution. In the extraction step, hydrogen peroxide in the oxidized solution is extracted with water to obtain crude hydrogen peroxide; the working solution flowing out of the extraction step is called the raffinate. In the post-treatment step, the raffinate undergoes dehydration, hydrogen peroxide removal, and regeneration of degradation products before entering the working solution storage tank, completing one cycle.

[0003] Depending on the reactor type used in the hydrogenation process, the anthraquinone process for producing hydrogen peroxide can be divided into fixed-bed and fluidized-bed processes. Currently, most hydrogen peroxide production plants in my country use the traditional fixed-bed process. Compared with the fixed-bed process, the fluidized-bed process has the advantages of uniform gas-liquid-solid three-phase mixing, better mass and heat transfer, higher hydrogen efficiency, and less degradation of effective anthraquinone, making it suitable for large-scale hydrogen peroxide plants (400,000 tons / year and above).

[0004] The catalyst used in the fluidized bed hydrogenation process is in powder form, typically palladium-supported alumina powder, which has a certain degree of hydrophilicity. When the water content in the working fluid is too high, especially when it contains free water, the catalyst is prone to agglomeration, leading to easy sedimentation and affecting the fluidization state of the catalyst. In the post-treatment process, vacuum dehydration and the installation of a raffinate coalescer are generally used to remove the water entrained in the working fluid (Chinese Patents CN201922109864.8, CN201310703884.2). This common dehydration process can remove moisture from the extraction process, but it has the following problems: The working fluid flowing into the circulating working fluid tank from the post-treatment process has a temperature of approximately 50-55°C. After being cooled to 35-45°C by the circulating working fluid cooler, it enters the fluidized bed hydrogenation tower. As the temperature decreases, the saturated water content of the working fluid decreases, and some dissolved water will be converted into free water. Simultaneously, due to the large flow rate of the working fluid, if the post-treatment process is not operating effectively, free water can easily be entrained in the working fluid. If this is not intercepted in time, some free water will enter the hydrogenation process. This free water can cause some catalyst to clump, preventing effective fluidization and catalytic activity.

[0005] After both gas and liquid phases enter the fluidized bed hydrogenation tower from the bottom, the gas and liquid phases carry catalyst particles and flow upwards. The particle density of the catalyst is typically 0.9~1.1 g / cm³. 3 Slightly higher than the density of the working fluid (0.9~0.95 g / cm³). 3 However, after the catalyst is soaked in the working fluid, it will adsorb a large amount of anthraquinone, which will increase the density of the catalyst particles in the working fluid and make them more prone to sedimentation.

[0006] To prevent catalyst particles from depositing at the bottom of the reactor, a gas distributor is typically used to purge the gas downwards. Chinese patent CN03151229.1 adds a dummy plate to the bottom of the reactor and uses downward-purged gas nozzles. The gas is sprayed onto the smooth dummy plate to prevent catalyst deposition. However, this results in the gas exiting the tubular distributor being directly sprayed downwards and impacting the bottom of the reactor. Even if small bubbles are formed, they easily coalesce into larger bubbles, leading to poor mass transfer between the gas, liquid, and solid phases.

[0007] In the three-phase fluidized bed design for anthraquinone hydrogenation, a liquid distributor is typically not used; instead, a downward-purged gas distribution pipe is employed. This approach increases the hydrogen circulation volume and gas flow rate, preventing catalyst deposition and promoting gas-liquid phase contact. However, this method requires a large gas circulation volume, with the circulation gas flow rate being 0.4 to 1 times the theoretical hydrogen consumption, thus increasing the energy consumption of the circulation gas compressor.

[0008] Furthermore, in actual production, there may be situations where the circulating working fluid pump suddenly fails, causing the liquid phase feed flow rate of the fluidized bed reactor to drop to zero, or the hydrogen circulation compressor to suddenly fail, preventing the replenishment of fresh hydrogen. At the outlet of the gas-liquid distributor, the fluid velocity is relatively high, and a sudden drop in velocity can cause some liquid or liquid-solid mixture in the reactor to be drawn back into the gas-liquid distributor. If the shutdown time is long, catalyst agglomeration may occur, leading to blockage of some small holes, affecting the subsequent use of the gas-liquid distributor. Summary of the Invention

[0009] To address the aforementioned problems, this invention provides a fluidized bed hydrogenation apparatus for producing hydrogen peroxide using the anthraquinone process.

[0010] The fluidized bed hydrogenation device can eliminate the influence of free water on the hydrogenation reaction; using liquid to purge the bottom of the tower greatly reduces catalyst deposition, avoids using gas to directly purge the bottom of the tower, greatly reduces bubble coalescence, promotes mass transfer between the gas and liquid phases, and can improve hydrogenation efficiency while reducing gas circulation volume; the emergency nitrogen replenishment system can prevent fluid backflow and blockage of the gas-liquid distributor under abnormal operating conditions.

[0011] The present invention adopts the following technical solution:

[0012] A fluidized bed hydrogenation apparatus for producing hydrogen peroxide using the anthraquinone process includes a circulating working fluid tank 1, a circulating working fluid pump 2, a circulating working fluid cooler 3, a shut-off valve 4, a circulating working fluid buffer tank 5, a fluidized bed hydrogenation tower 10, and a hydrogen pipeline 7. The fluidized bed hydrogenation tower 10 is equipped with a gas distributor 12 and a liquid distributor 13. The circulating working fluid from the circulating working fluid tank 1 passes through the circulating working fluid pump 2, the circulating working fluid cooler 3, the shut-off valve 4, and the circulating working fluid buffer tank 5, and then enters the fluidized bed hydrogenation tower 10 through the liquid distributor 13. The hydrogen pipeline 7 is connected to the gas distributor 12. The circulating working fluid buffer tank 5 is equipped with a coalescing filter element and a separating filter element.

[0013] Furthermore, the fluidized bed hydrogenation device is equipped with an emergency nitrogen replenishment system, which includes a nitrogen pipeline 6, an emergency nitrogen replenishment valve A 8, and an emergency nitrogen replenishment valve B 9. The nitrogen pipeline 6 is divided into two branches, one of which is connected to the hydrogen pipeline 7 via the emergency nitrogen replenishment valve A 8, and the other branch is connected to the circulating working fluid buffer tank 5 via the emergency nitrogen replenishment valve B 9.

[0014] Furthermore, when fresh hydrogen cannot be supplied due to a malfunction, the emergency nitrogen replenishment valve A8 is activated, and emergency nitrogen is supplied to the fluidized bed hydrogenation tower 10.

[0015] Furthermore, when the circulating working fluid pump 2 suddenly stops, the shut-off valve 4 closes, the emergency nitrogen replenishment valve B 9 opens, and emergency nitrogen replenishment enters the circulating working fluid buffer tank 5, which in turn pumps the working fluid into the fluidized bed hydrogenation tower 10; at the same time, the emergency nitrogen replenishment valve A 8 starts, and emergency nitrogen replenishment enters the fluidized bed hydrogenation tower 10.

[0016] Furthermore, the working fluid outlet of the circulating working fluid buffer tank 5 is located in the middle of the side of the circulating working fluid buffer tank 5. After the emergency nitrogen replenishment valve B9 is opened, the liquid level of the circulating working fluid buffer tank 5 drops. When the liquid level drops to the same height as the working fluid outlet, the emergency nitrogen replenishment valve B9 closes.

[0017] Furthermore, the gas distributor 12 has an upward outlet, and the liquid distributor 13 has a downward outlet; the gas distributor 12 is located above the liquid distributor 13, preferably 0.2~0.5m above the liquid distributor 13.

[0018] Furthermore, the liquid distributor 13 can be a ring-type fluid distributor or a pipe-type fluid distributor. The outlet of the liquid distributor 13 can be a circular orifice or a downward-facing nozzle. By setting the nozzle, the liquid jet length is increased, further reducing catalyst deposition. Preferably, the orifice diameter is 0.1~20mm, more preferably 0.1~10mm, the orifice ratio is 0.1~10%, more preferably 0.1~5%, and the liquid perforation velocity is 0.3~10m / s, more preferably 0.5~5m / s.

[0019] Furthermore, each outlet of the liquid distributor 13 is equidistant from the bottom of the fluidized bed hydrogenation tower 10, preferably 10-200 mm.

[0020] Furthermore, the gas distributor 12 can be a ring-type fluid distributor or a pipe-type fluid distributor. The outlet of the gas distributor 12 is provided with a gas cap, which is shaped like a spherical cap or a cone. Preferably, the gas cap is shaped like a spherical cap, and more preferably, it is shaped like a hemispherical cap. Preferably, the top of the gas cap is composed of a sintered metal mesh, and the aperture of the sintered metal mesh is preferably 0.2~50μm.

[0021] Furthermore, the fluidized bed hydrogenation device is equipped with a circulating gas compressor 11. The circulating gas at the top of the fluidized bed hydrogenation tower 10 is compressed by the circulating gas compressor 11 and mixed with fresh hydrogen before entering the fluidized bed hydrogenation tower 10.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] (1) This invention sets up a working fluid buffer tank between the working fluid cooler and the fluidized bed reactor, and sets up a coalescing filter element and a separating filter element in the working fluid buffer tank. The coalescing filter element can condense the fine water droplets in the working fluid into larger water droplets, making the water phase entrained in the working fluid easier to settle. The separating filter element has oleophilic properties, so the working fluid can easily pass through the separating filter element, while the water phase cannot easily pass through the separating filter element, further removing water from the working fluid. Through the above design, when the post-treatment process is not running well, the working fluid carries free water, the working fluid temperature drops, and the dissolved water precipitates as free water, the free water can be effectively removed, effectively eliminating the phenomenon of catalyst agglomeration caused by excessive water, improving the catalyst utilization rate, and ensuring the fluidization effect of the catalyst.

[0024] (2) The present invention is equipped with an emergency nitrogen replenishment system and a circulating working fluid buffer tank, which can maintain the flow of gas and liquid two-phase fluid for a certain period of time when the gas phase or liquid phase suddenly stops, prevent catalyst particles from covering the gas cap of the gas distributor, and prevent catalyst particles from being drawn back into the liquid distributor.

[0025] (3) The working fluid outlet of the circulating working fluid buffer tank of the present invention is located in the middle of the side of the circulating working fluid buffer tank. After the emergency nitrogen replenishment valve B is opened, the liquid level of the circulating working fluid buffer tank drops. When the liquid level drops to the same height as the working fluid outlet, the emergency nitrogen replenishment valve B closes. This prevents excessive nitrogen from entering the liquid distributor and effectively ensures the anti-backflow effect of the liquid.

[0026] (4) The present invention designs a gas-liquid two-phase separate feed distributor. The liquid distributor is located below the gas distributor and the liquid distributor opens downward. It can make full use of the large liquid flow rate of the anthraquinone hydrogen peroxide production process, use liquid to purge the bottom of the tower, greatly reduce catalyst deposition, avoid using gas to purge the bottom of the tower, greatly reduce bubble aggregation, and promote mass transfer between the gas and liquid phases.

[0027] (5) The gas distributor of the present invention has an upward opening and is equipped with a metal sintered wire mesh as a gas distribution device, which can effectively prevent the collision of bubbles while increasing the gas dispersion area and effectively prevent catalyst particles from entering the gas distributor.

[0028] (6) The gas-liquid distributor of the present invention promotes the fluidization of catalyst particles and enhances the contact and mass transfer between the gas and liquid phases, thereby improving hydrogenation efficiency while reducing the gas circulation volume. Attached Figure Description

[0029] Figure 1 The fluidized bed hydrogenation apparatus for producing hydrogen peroxide via the anthraquinone process of the present invention;

[0030] Figure 2 A schematic diagram of the appearance of a pipe-type fluid distributor;

[0031] Figure 3 This is a schematic diagram of the appearance of a loop fluid distributor;

[0032] Wherein: 1 is the circulating working fluid tank, 2 is the circulating working fluid pump, 3 is the circulating working fluid cooler, 4 is the shut-off valve, 5 is the circulating working fluid buffer tank, 6 is the nitrogen pipeline, 7 is the hydrogen pipeline, 8 is the emergency nitrogen replenishment valve A, 9 is the emergency nitrogen replenishment valve B, 10 is the fluidized bed hydrogenation tower, 11 is the circulating gas compressor, 12 is the gas distributor, 13 is the liquid distributor, 14 is the fluid inlet of the pipe-type fluid distributor, and 15 is the fluid inlet of the loop-type fluid distributor. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The following embodiments are merely descriptive and should not be construed as limiting the scope of protection of the present invention.

[0034] Example 1

[0035] A hydrogen peroxide production unit with a designed capacity of 400,000 tons / year has a working fluid flow rate of 1300 m³ / h. 3 / h, top pressure 0.1~0.15MPa, using the fluidized bed hydrogenation device described in this invention, including a circulating working fluid tank 1, a circulating working fluid pump 2, a circulating working fluid cooler 3, a shut-off valve 4, a circulating working fluid buffer tank 5, a fresh hydrogen pipeline 7, a fluidized bed hydrogenation tower 10, a circulating gas compressor 11, and an emergency nitrogen replenishment system. The fluidized bed hydrogenation tower 10 is equipped with a liquid distributor 13 and a gas distributor 12. The emergency nitrogen replenishment system includes a nitrogen pipeline 6, an emergency nitrogen replenishment valve A 8, and an emergency nitrogen replenishment valve B. 9. The circulating working fluid from the circulating working fluid tank 1 passes through the circulating working fluid pump 2, the circulating working fluid cooler 3, the shut-off valve 4, and the circulating working fluid buffer tank 5, and enters the fluidized bed hydrogenation tower 10 through the liquid distributor 13 located at the bottom of the fluidized bed hydrogenation tower 10. The circulating gas at the top of the fluidized bed hydrogenation tower 10 is compressed by the circulating gas compressor 11 and mixed with the fresh hydrogen gas from the hydrogen pipeline 7, and enters the fluidized bed hydrogenation tower 10. After being dispersed by the gas distributor 12, it flows upward. The circulating working fluid buffer tank 5 is equipped with a coalescing filter and a separating filter. The nitrogen pipeline 6 of the emergency nitrogen replenishment system is divided into two branches. One branch is connected to the hydrogen pipeline 7 through the emergency nitrogen replenishment valve A 8, and the other branch is connected to the circulating working fluid buffer tank 5 through the emergency nitrogen replenishment valve B 9.

[0036] The gas distributor is located above the liquid distributor, the gas distributor has an upward outlet, and the liquid distributor has a downward outlet;

[0037] The gas distributor is a ring pipe type, and the liquid distributor is a pipe-type type. The gas distributor is located 0.3m above the liquid distributor.

[0038] The outlet of the liquid distributor is a circular orifice with a diameter of 6 mm and an opening ratio of 0.8%. The liquid perforation velocity is 1.5 m / s.

[0039] The outlet of the liquid distributor is close to the inner surface of the bottom head of the reactor, and each liquid outlet is equidistant from the bottom of the reactor, at a distance of 50 mm;

[0040] The outlet of the gas distributor faces upward and is equipped with a gas cap. The top of the gas cap is composed of a sintered metal wire mesh. The gas cap is hemispherical in shape and the aperture of the sintered metal wire mesh is 5μm.

[0041] The temperature of the circulating working fluid tank in this device is 50℃, and the outlet temperature of the circulating working fluid cooler is 45℃. The circulating working fluid buffer tank is filled with coalescing filter elements and separation filter elements. It can discharge 180kg of water phase per hour, which effectively ensures the activity and life of the catalyst and prevents excessive water from entering the fluidized bed hydrogenation tower.

[0042] The circulating gas flow rate is 1000~2000 Nm³. 3 / h, the catalyst deposition at the bottom of the reactor accounts for 1~2wt% of the catalyst loading, and the hydrogen efficiency can reach 15g / L.

[0043] Example 2

[0044] A hydrogen peroxide production unit with a designed capacity of 130,000 tons / year has a working fluid flow rate of 600 m³ / h. 3 / h, top pressure 0.1~0.15MPa, using the fluidized bed hydrogenation device described in this invention, including a circulating working fluid tank 1, a circulating working fluid pump 2, a circulating working fluid cooler 3, a shut-off valve 4, a circulating working fluid buffer tank 5, a fresh hydrogen pipeline 7, a fluidized bed hydrogenation tower 10, a circulating gas compressor 11, and an emergency nitrogen replenishment system. The fluidized bed hydrogenation tower 10 is equipped with a liquid distributor 13 and a gas distributor 12. The emergency nitrogen replenishment system includes a nitrogen pipeline 6, an emergency nitrogen replenishment valve A 8, and an emergency nitrogen replenishment valve B. 9. The circulating working fluid from the circulating working fluid tank 1 passes through the circulating working fluid pump 2, the circulating working fluid cooler 3, the shut-off valve 4, and the circulating working fluid buffer tank 5, and enters the fluidized bed hydrogenation tower 10 through the liquid distributor 13 located at the bottom of the fluidized bed hydrogenation tower 10. The circulating gas at the top of the fluidized bed hydrogenation tower 10 is compressed by the circulating gas compressor 11 and mixed with the fresh hydrogen gas from the hydrogen pipeline 7, and enters the fluidized bed hydrogenation tower 10. After being dispersed by the gas distributor 12, it flows upward. The circulating working fluid buffer tank 5 is equipped with a coalescing filter and a separating filter. The nitrogen pipeline 6 of the emergency nitrogen replenishment system is divided into two branches. One branch is connected to the hydrogen pipeline 7 through the emergency nitrogen replenishment valve A 8, and the other branch is connected to the circulating working fluid buffer tank 5 through the emergency nitrogen replenishment valve B 9.

[0045] The gas distributor is located above the liquid distributor, the gas distributor has an upward outlet, and the liquid distributor has a downward outlet;

[0046] The gas distributor is a pipe-type system, and the liquid distributor is a ring-type system. The gas distributor is located 0.4m above the liquid distributor.

[0047] The outlet of the liquid distributor is a circular orifice with a diameter of 2 mm and an opening ratio of 0.6%. The liquid perforation velocity is 2 m / s.

[0048] The outlet of the liquid distributor is close to the inner surface of the bottom head of the reactor, and each liquid outlet is equidistant from the bottom of the reactor, at a distance of 80 mm;

[0049] The outlet of the gas distributor faces upward and is equipped with a gas cap. The top of the gas cap is composed of a sintered metal wire mesh. The gas cap is hemispherical in shape and the aperture of the sintered metal wire mesh is 10μm.

[0050] The circulating gas flow rate of this device is 350~1000 Nm³. 3 / h, the catalyst deposition at the bottom of the reactor accounts for 1~2wt% of the catalyst loading, and the hydrogen efficiency can reach 15g / L;

[0051] Due to a working fluid pump malfunction, an emergency shutdown was initiated, and the emergency nitrogen replenishment system was activated. The shut-off valve was closed, and emergency nitrogen replenishment valve B was opened, allowing emergency nitrogen to enter the circulating working fluid buffer tank, which then pumped the working fluid into the fluidized bed hydrogenation tower. Simultaneously, emergency nitrogen replenishment valve A was activated, mixing the emergency nitrogen with the circulating gas before entering the fluidized bed hydrogenation tower. After emergency nitrogen replenishment valve B opened, the liquid level in the circulating working fluid buffer tank dropped. When the level reached the same height as the working fluid outlet (located in the middle of the side of the circulating working fluid buffer tank), emergency nitrogen replenishment valve B closed. After the working fluid pump was repaired and restarted, there was no clogging of the liquid distributor channels or coverage of the gas distributor cap by the working fluid or catalyst. The gas-liquid-solid three-phase fluidization was good, and the catalyst activity was unaffected.

[0052] Example 3

[0053] A hydrogen peroxide production unit with a designed capacity of 400,000 tons / year has a working fluid flow rate of 1300 m³ / h. 3 / h, top pressure 0.1~0.15MPa, using the fluidized bed hydrogenation device described in this invention, including a circulating working fluid tank 1, a circulating working fluid pump 2, a circulating working fluid cooler 3, a shut-off valve 4, a circulating working fluid buffer tank 5, a fresh hydrogen pipeline 7, a fluidized bed hydrogenation tower 10, a circulating gas compressor 11, and an emergency nitrogen replenishment system. The fluidized bed hydrogenation tower 10 is equipped with a liquid distributor 13 and a gas distributor 12. The emergency nitrogen replenishment system includes a nitrogen pipeline 6, an emergency nitrogen replenishment valve A 8, and an emergency nitrogen replenishment valve B. 9. The circulating working fluid from the circulating working fluid tank 1 passes through the circulating working fluid pump 2, the circulating working fluid cooler 3, the shut-off valve 4, and the circulating working fluid buffer tank 5, and enters the fluidized bed hydrogenation tower 10 through the liquid distributor 13 located at the bottom of the fluidized bed hydrogenation tower 10. The circulating gas at the top of the fluidized bed hydrogenation tower 10 is compressed by the circulating gas compressor 11 and mixed with the fresh hydrogen gas from the hydrogen pipeline 7, and enters the fluidized bed hydrogenation tower 10. After being dispersed by the gas distributor 12, it flows upward. The circulating working fluid buffer tank 5 is equipped with a coalescing filter and a separating filter. The nitrogen pipeline 6 of the emergency nitrogen replenishment system is divided into two branches. One branch is connected to the hydrogen pipeline 7 through the emergency nitrogen replenishment valve A 8, and the other branch is connected to the circulating working fluid buffer tank 5 through the emergency nitrogen replenishment valve B 9.

[0054] The gas distributor is located above the liquid distributor, the gas distributor has an upward outlet, and the liquid distributor has a downward outlet;

[0055] The gas distributor is a pipe-type, and the liquid distributor is a ring-type. The gas distributor is located 0.2m above the liquid distributor.

[0056] The outlet of the liquid distributor is a circular orifice with a diameter of 0.1 mm and an opening ratio of 0.1%. The liquid perforation velocity is 10 m / s.

[0057] The outlet of the liquid distributor is close to the inner surface of the bottom head of the reactor, and each liquid outlet is 200mm away from the bottom of the reactor.

[0058] The outlet of the gas distributor faces upward and is equipped with a gas cap. The top of the gas cap is composed of a sintered metal wire mesh. The gas cap is hemispherical in shape and the aperture of the sintered metal wire mesh is 2μm.

[0059] The circulating gas flow rate of this device is 1500~2000 Nm³. 3 / h, the catalyst deposition at the bottom of the reactor accounts for 2~4wt% of the catalyst loading, and the hydrogen efficiency can reach 15g / L.

[0060] Example 4

[0061] A hydrogen peroxide production unit with a designed capacity of 130,000 tons / year has a working fluid flow rate of 600 m³ / h. 3 / h, top pressure 0.1~0.15MPa, using the fluidized bed hydrogenation device described in this invention, including a circulating working fluid tank 1, a circulating working fluid pump 2, a circulating working fluid cooler 3, a shut-off valve 4, a circulating working fluid buffer tank 5, a fresh hydrogen pipeline 7, a fluidized bed hydrogenation tower 10, a circulating gas compressor 11, and an emergency nitrogen replenishment system. The fluidized bed hydrogenation tower 10 is equipped with a liquid distributor 13 and a gas distributor 12. The emergency nitrogen replenishment system includes a nitrogen pipeline 6, an emergency nitrogen replenishment valve A 8, and an emergency nitrogen replenishment valve B. 9. The circulating working fluid from the circulating working fluid tank 1 passes through the circulating working fluid pump 2, the circulating working fluid cooler 3, the shut-off valve 4, and the circulating working fluid buffer tank 5, and enters the fluidized bed hydrogenation tower 10 through the liquid distributor 13 located at the bottom of the fluidized bed hydrogenation tower 10. The circulating gas at the top of the fluidized bed hydrogenation tower 10 is compressed by the circulating gas compressor 11 and mixed with the fresh hydrogen gas from the hydrogen pipeline 7, and enters the fluidized bed hydrogenation tower 10. After being dispersed by the gas distributor 12, it flows upward. The circulating working fluid buffer tank 5 is equipped with a coalescing filter and a separating filter. The nitrogen pipeline 6 of the emergency nitrogen replenishment system is divided into two branches. One branch is connected to the hydrogen pipeline 7 through the emergency nitrogen replenishment valve A 8, and the other branch is connected to the circulating working fluid buffer tank 5 through the emergency nitrogen replenishment valve B 9.

[0062] The gas distributor is located above the liquid distributor, the gas distributor has an upward outlet, and the liquid distributor has a downward outlet;

[0063] The gas distributor is a pipe-type, and the liquid distributor is a ring-type. The gas distributor is located 0.2m above the liquid distributor.

[0064] The liquid distributor has a nozzle outlet with a diameter of 5 mm, an orifice ratio of 5%, and a liquid perforation velocity of 0.3 m / s.

[0065] The outlet of the liquid distributor is close to the inner surface of the bottom head of the reactor, and each liquid outlet is equidistant from the bottom of the reactor, at a distance of 20 mm;

[0066] The outlet of the gas distributor faces upward and is equipped with a gas cap. The top of the gas cap is composed of a sintered metal wire mesh. The gas cap is hemispherical in shape and the aperture of the sintered metal wire mesh is 20μm.

[0067] The circulating gas flow rate of this device is 350~1000 Nm³. 3 / h, the catalyst deposition at the bottom of the reactor accounts for 0.5~2wt% of the catalyst loading, and the hydrogen efficiency can reach 14g / L;

[0068] The circulating working fluid tank temperature is 50℃, and the circulating working fluid cooler outlet temperature is 42℃. The circulating working fluid buffer tank is filled with coalescing filter element and separation filter element. It can discharge 150kg of water phase per hour, which effectively ensures the activity and life of the catalyst and prevents excessive water from entering the fluidized bed hydrogenation tower.

[0069] Example 5

[0070] A hydrogen peroxide production unit with a designed capacity of 400,000 tons / year has a working fluid flow rate of 1300 m³ / h. 3 / h, top pressure 0.1~0.15MPa, using the fluidized bed hydrogenation device described in this invention, including a circulating working fluid tank 1, a circulating working fluid pump 2, a circulating working fluid cooler 3, a shut-off valve 4, a circulating working fluid buffer tank 5, a fresh hydrogen pipeline 7, a fluidized bed hydrogenation tower 10, a circulating gas compressor 11, and an emergency nitrogen replenishment system. The fluidized bed hydrogenation tower 10 is equipped with a liquid distributor 13 and a gas distributor 12. The emergency nitrogen replenishment system includes a nitrogen pipeline 6, an emergency nitrogen replenishment valve A 8, and an emergency nitrogen replenishment valve B. 9. The circulating working fluid from the circulating working fluid tank 1 passes through the circulating working fluid pump 2, the circulating working fluid cooler 3, the shut-off valve 4, and the circulating working fluid buffer tank 5, and enters the fluidized bed hydrogenation tower 10 through the liquid distributor 13 located at the bottom of the fluidized bed hydrogenation tower 10. The circulating gas at the top of the fluidized bed hydrogenation tower 10 is compressed by the circulating gas compressor 11 and mixed with the fresh hydrogen gas from the hydrogen pipeline 7, and enters the fluidized bed hydrogenation tower 10. After being dispersed by the gas distributor 12, it flows upward. The circulating working fluid buffer tank 5 is equipped with a coalescing filter and a separating filter. The nitrogen pipeline 6 of the emergency nitrogen replenishment system is divided into two branches. One branch is connected to the hydrogen pipeline 7 through the emergency nitrogen replenishment valve A 8, and the other branch is connected to the circulating working fluid buffer tank 5 through the emergency nitrogen replenishment valve B 9.

[0071] The gas distributor is located above the liquid distributor, the gas distributor has an upward outlet, and the liquid distributor has a downward outlet;

[0072] The gas distributor is a ring type, and the liquid distributor is a ring pipe type. The gas distributor is located 0.3m above the liquid distributor.

[0073] The liquid distributor has a nozzle outlet with an orifice diameter of 10 mm, an orifice ratio of 2%, and a liquid perforation velocity of 0.5 m / s.

[0074] The outlet of the liquid distributor is close to the inner surface of the bottom head of the reactor, and each liquid outlet is equidistant from the bottom of the reactor, at a distance of 40 mm;

[0075] The outlet of the gas distributor faces upward and is equipped with a gas cap. The top of the gas cap is composed of a sintered metal wire mesh. The gas cap is hemispherical in shape and the aperture of the sintered metal wire mesh is 10μm.

[0076] The circulating gas flow rate of this device is 2500~3000 Nm³. 3 / h, the catalyst deposition at the bottom of the reactor accounts for 0.2~1wt% of the catalyst loading, and the hydrogen efficiency can reach 14.5g / L;

[0077] Due to a working fluid pump malfunction, an emergency shutdown was initiated, and the emergency nitrogen replenishment system was activated. The shut-off valve was closed, and emergency nitrogen replenishment valve B was opened, allowing emergency nitrogen to enter the circulating working fluid buffer tank, which then pumped the working fluid into the fluidized bed hydrogenation tower. Simultaneously, emergency nitrogen replenishment valve A was activated, mixing the emergency nitrogen with the circulating gas before entering the fluidized bed hydrogenation tower. After emergency nitrogen replenishment valve B opened, the liquid level in the circulating working fluid buffer tank dropped. When the level reached the same height as the working fluid outlet (located in the middle of the side of the circulating working fluid buffer tank), emergency nitrogen replenishment valve B closed. After the working fluid pump was repaired and restarted, there was no clogging of the liquid distributor channels or coverage of the gas distributor cap by the working fluid or catalyst. The gas-liquid-solid three-phase fluidization was good, and the catalyst activity was unaffected.

[0078] Example 6

[0079] A hydrogen peroxide production unit with a designed capacity of 400,000 tons / year has a working fluid flow rate of 1300 m³ / h. 3 / h, top pressure 0.1~0.15MPa, using the fluidized bed hydrogenation device described in this invention, including a circulating working fluid tank 1, a circulating working fluid pump 2, a circulating working fluid cooler 3, a shut-off valve 4, a circulating working fluid buffer tank 5, a fresh hydrogen pipeline 7, a fluidized bed hydrogenation tower 10, a circulating gas compressor 11, and an emergency nitrogen replenishment system. The fluidized bed hydrogenation tower 10 is equipped with a liquid distributor 13 and a gas distributor 12. The emergency nitrogen replenishment system includes a nitrogen pipeline 6, an emergency nitrogen replenishment valve A 8, and an emergency nitrogen replenishment valve B. 9. The circulating working fluid from the circulating working fluid tank 1 passes through the circulating working fluid pump 2, the circulating working fluid cooler 3, the shut-off valve 4, and the circulating working fluid buffer tank 5, and enters the fluidized bed hydrogenation tower 10 through the liquid distributor 13 located at the bottom of the fluidized bed hydrogenation tower 10. The circulating gas at the top of the fluidized bed hydrogenation tower 10 is compressed by the circulating gas compressor 11 and mixed with the fresh hydrogen gas from the hydrogen pipeline 7, and enters the fluidized bed hydrogenation tower 10. After being dispersed by the gas distributor 12, it flows upward. The circulating working fluid buffer tank 5 is equipped with a coalescing filter and a separating filter. The nitrogen pipeline 6 of the emergency nitrogen replenishment system is divided into two branches. One branch is connected to the hydrogen pipeline 7 through the emergency nitrogen replenishment valve A 8, and the other branch is connected to the circulating working fluid buffer tank 5 through the emergency nitrogen replenishment valve B 9.

[0080] The gas distributor is located above the liquid distributor, the gas distributor has an upward outlet, and the liquid distributor has a downward outlet;

[0081] The gas distributor is a pipe-type system, and the liquid distributor is also a pipe-type system. The gas distributor is located 0.5m above the liquid distributor.

[0082] The outlet of the liquid distributor is a circular orifice with a diameter of 0.5 mm and an opening ratio of 1%. The liquid perforation velocity is 1 m / s.

[0083] The outlet of the liquid distributor is close to the inner surface of the bottom head of the reactor, and each liquid outlet is 100mm away from the bottom of the reactor.

[0084] The outlet of the gas distributor faces upward and is equipped with a gas cap. The top of the gas cap is composed of sintered metal wire mesh. The gas cap is hemispherical in shape and the pore size of the sintered metal wire mesh is 0.2μm.

[0085] The circulating gas flow rate of this device is 2000~3000 Nm³. 3 / h, the catalyst deposition at the bottom of the reactor accounts for 2~4wt% of the catalyst loading, and the hydrogen efficiency can reach 14g / L.

[0086] Comparative Example 1

[0087] A hydrogen peroxide production unit with a designed capacity of 400,000 tons / year has a working fluid flow rate of 1300 m³ / h. 3 The flow rate is 8000~10000 Nm³ / h, with a top pressure of 0.1~0.15 MPa. Compared with Example 1, the fluidized bed hydrogenation unit does not have a circulating working fluid buffer tank, an emergency nitrogen replenishment system, or a liquid distributor. Its process is as follows: The circulating working fluid from the circulating working fluid tank passes through the circulating working fluid pump and the circulating working fluid cooler, and then directly enters the fluidized bed hydrogenation tower from the working fluid inlet. No liquid distributor is installed. The circulating gas at the top of the fluidized bed hydrogenation tower is compressed by the circulating gas compressor and mixed with fresh hydrogen before entering the fluidized bed hydrogenation tower. The gas distributor is located below the working fluid inlet, and is a pipe-type gas distributor with downward-facing openings. The circulating gas flow rate of this unit is 8000~10000 Nm³ / h. 3 / h, the catalyst deposition at the bottom of the reactor accounts for 5~10wt% of the catalyst loading, and the hydrogen efficiency is 11~12g / L;

[0088] After a period of stable operation, the working fluid pump suddenly failed and the machine was shut down. This caused the working fluid in the fluidized bed hydrogenation tower to carry the catalyst back into the gas distributor. After the working fluid pump was repaired and restarted, it was found that the catalyst blocked some of the gas distributor channels, causing gas flow deviation, uneven catalyst mixing, and decreased catalyst activity. After 72 hours of low-load operation, the blocked channels were gradually cleared and the catalyst activity was restored.

[0089] Comparative Example 2

[0090] A hydrogen peroxide production unit with a designed capacity of 130,000 tons / year adopts a fluidized bed hydrogenation process with a working fluid flow rate of 600 m³ / h. 3The flow rate is 0.1~0.15MPa. Compared with Example 1, the fluidized bed hydrogenation unit does not have a circulating working fluid buffer tank, an emergency nitrogen replenishment system, or a liquid distributor. Its process is as follows: The circulating working fluid from the circulating working fluid tank passes through the circulating working fluid pump and the circulating working fluid cooler, and then directly enters the fluidized bed hydrogenation tower from the working fluid inlet. No liquid distributor is installed. The circulating gas at the top of the fluidized bed hydrogenation tower is compressed by the circulating gas compressor and mixed with fresh hydrogen before entering the fluidized bed hydrogenation tower. The gas distributor is located below the working fluid inlet and is a pipe-type distributor with downward-facing openings. The circulating gas flow rate of this unit is 3500~4000 Nm³. 3 / h, the catalyst deposition at the bottom of the reactor accounts for 6~12wt% of the catalyst loading, and the hydrogen efficiency is 9.5~11g / L;

[0091] After passing through the circulating working fluid cooler, the working fluid temperature decreased. Sampling revealed that the working fluid contained a large amount of free water, but the free water could not be discharged, resulting in a decrease in catalyst activity. After adding 300 kg of catalyst, the activity gradually recovered.

Claims

1. A fluidized bed hydrogenation device for producing hydrogen peroxide by anthraquinone method, comprising a circulating working liquid tank (1), a circulating working liquid pump (2), a circulating working liquid cooler (3), a cut-off valve (4), a circulating working liquid buffer tank (5), a fluidized bed hydrogenation tower (10), and a hydrogen pipeline (7), wherein the fluidized bed hydrogenation tower (10) is provided with a gas distributor (12) and a liquid distributor (13); the circulating working liquid from the circulating working liquid tank (1) enters the fluidized bed hydrogenation tower (10) through the liquid distributor (13) after passing through the circulating working liquid pump (2), the circulating working liquid cooler (3), the cut-off valve (4), and the circulating working liquid buffer tank (5), and the hydrogen pipeline (7) is connected with the gas distributor (12); the circulating working liquid buffer tank (5) is provided with a coalescence filter element and a separation filter element. The gas distributor (12) has an upward outlet, and the liquid distributor (13) has a downward outlet; the gas distributor (12) is located above the liquid distributor (13).

2. The fluidized bed hydrogenation apparatus according to claim 1, characterized by The fluidized bed hydrogenation device is provided with an emergency nitrogen supplement system, which comprises a nitrogen pipeline (6), an emergency nitrogen supplement valve A (8), and an emergency nitrogen supplement valve B (9); the nitrogen pipeline (6) is divided into two branches, one branch is connected with the hydrogen pipeline (7) through the emergency nitrogen supplement valve A (8), and the other branch is connected with the circulating working liquid buffer tank (5) through the emergency nitrogen supplement valve B (9).

3. The fluidized bed hydrogenation apparatus according to claim 2, wherein When fresh hydrogen cannot be supplied due to a fault, the emergency nitrogen supplement valve A (8) is started, and emergency nitrogen is supplied into the fluidized bed hydrogenation tower (10).

4. The fluidized bed hydrogenation apparatus according to claim 2, wherein When the circulating working liquid pump (2) suddenly stops, the cut-off valve (4) is closed, the emergency nitrogen supplement valve B (9) is opened, emergency nitrogen is supplied into the circulating working liquid buffer tank (5), and the working liquid in the circulating working liquid buffer tank (5) is pressed into the fluidized bed hydrogenation tower (10); at the same time, the emergency nitrogen supplement valve A (8) is started, and emergency nitrogen is supplied into the fluidized bed hydrogenation tower (10).

5. The fluidized bed hydrogenation apparatus according to claim 2, wherein The working liquid outlet of the circulating working liquid buffer tank (5) is located in the middle of the side of the circulating working liquid buffer tank (5); after the emergency nitrogen supplement valve B (9) is opened, the liquid level of the circulating working liquid buffer tank (5) drops, and when the liquid level is lowered to the same height as the working liquid outlet, the emergency nitrogen supplement valve B (9) is closed.

6. The fluidized bed hydrogenation apparatus according to claim 1 or 2, characterized by The gas distributor (12) is located 0.2-0.5 m above the liquid distributor (13).

7. The fluidized bed hydrogenation apparatus according to claim 6, wherein The outlet of the liquid distributor (13) is a circular hole or an opening downward nozzle.

8. The fluidized bed hydrogenation apparatus according to claim 7, wherein The pore diameter of the liquid distributor (13) is 0.1-20 mm, the opening rate is 0.1-10%, and the perforation flow rate of the liquid is 0.3-10 m / s.

9. The fluidized bed hydrogenation apparatus according to claim 8, wherein, The pore diameter of the liquid distributor (13) is 0.1-10 mm, the opening rate is 0.1-5%, and the perforation flow rate of the liquid is 0.5-5 m / s.

10. The fluidized bed hydrogenation apparatus of claim 6, wherein, Each outlet of the liquid distributor (13) is equidistant from the bottom of the fluidized bed hydrogenation tower (10).

11. The fluidized bed hydrogenation apparatus according to claim 10, wherein Each outlet of the liquid distributor (13) is 10-200 mm away from the bottom of the fluidized bed hydrogenation tower (10).

12. The fluidized bed hydrogenation apparatus of claim 6, wherein, The outlet of the gas distributor (12) is provided with a gas cap, and the shape of the gas cap is a spherical segment or a conical shape.

13. The fluidized bed hydrogenation apparatus of claim 12, wherein, The shape of the gas cap is a spherical segment.

14. The fluidized bed hydrogenation apparatus of claim 13, wherein, The shape of the gas cap is a hemisphere.

15. The fluidized bed hydrogenation apparatus of claim 12, wherein, The top of the gas cap is composed of a metal sintered wire mesh.

16. The fluidized bed hydrogenation apparatus of claim 15, wherein, The pore size of the metal sintered wire mesh is 0.2-50 microns.

17. The fluidized bed hydrogenation apparatus according to claim 1 or 2, characterized by The fluidized bed hydrogenation device is provided with a circulating gas compressor (11), and the circulating gas at the top of the fluidized bed hydrogenation tower (10) is compressed by the circulating gas compressor (11), mixed with fresh hydrogen, and then enters the fluidized bed hydrogenation tower (10).

18. The fluidized bed hydrogenation apparatus according to claim 1 or 2, characterized by The gas distributor is a loop pipe fluid distributor or a tube bank fluid distributor, and the liquid distributor is a loop pipe fluid distributor or a tube bank fluid distributor.

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