Slurry bed hydrogenation reactor for producing hydrogen peroxide by anthraquinone process

Abstract

The utility model relates to a slurry bed hydrogenation reactor for producing hydrogen peroxide by an anthraquinone process. The slurry bed hydrogenation reactor comprises a hydrogenation reactor, a recycle gas condenser and a degassing tank, wherein the bottom of the hydrogenation reactor is provided with a working solution feeding distributor and a hydrogen feeding distributor, the middle of the hydrogenation reactor is provided with a gas raising cylinder, the gas raising cylinder and a straight cylinder at the lower part of the reactor have the same diameter and are provided with a gap, and an overflow area is arranged above the gas raising cylinder; an annular space between the gas raising cylinder and the upper expanded section of the reactor is a discharging standing area, a discharging baffle is arranged at a discharging port of the standing area, a discharging pipe is connected with a degassing tank, and a gas phase balance pipe and a gas-liquid balance pipe are sequentially arranged at the top of the degassing tank from top to bottom; the top of the hydrogenation reactor is connected with the recycle gas condenser. By adopting internal and external circulation two-stage degassing and solid separation, the conditions that the discharged material of the hydrogen reactor carries hydrogen and the concentration of a catalyst is too high are avoided, and the consumption of raw materials is reduced.

Description

Technical Field

[0001] The utility model relates to the field of preparing hydrogen peroxide by the anthraquinone method, and particularly relates to a slurry bed hydrogenation reactor for producing hydrogen peroxide by the anthraquinone method. Background Technique

[0002] As an important inorganic chemical raw material, hydrogen peroxide is widely used in many fields such as papermaking, textile, chemical industry, environmental protection, and electronic component manufacturing. At present, the industrial method for producing hydrogen peroxide is the anthraquinone method. In this method, alkyl anthraquinone dissolved in a mixed organic solvent is used as the carrier for cyclic hydrogenation and oxidation, and hydrogen peroxide with a certain concentration is obtained through a series of processes such as hydrogenation, oxidation, extraction, and post-treatment.

[0003] According to the different ways of anthraquinone hydrogenation, the process of preparing hydrogen peroxide by the anthraquinone method is divided into a fixed bed process and a slurry bed process. Among them, due to factors such as uneven heat transfer and bypass flow in the fixed bed process, anthraquinone is easily over-hydrogenated during hydrogenation to generate a series of by-products, thus increasing the consumption of anthraquinone and hydrogen. In addition, the fixed bed process also faces great limitations when the device is scaled up. Therefore, the fixed bed process is mainly applicable to devices with small production capacity. Compared with the fixed bed process, the slurry bed process (see Chinese patents CN206613468U and CN209721588U) uses microsphere catalysts, and due to the good heat and mass transfer characteristics of the slurry bed, the by-products are significantly reduced compared with the fixed bed process. Therefore, the slurry bed process is an inevitable choice for large-scale devices. However, due to the very high gas holdup in the slurry bed and the suspension of the catalyst in the hydrogenated liquid, the degassing and solid-liquid separation of the hydrogenated liquid are important parts of the slurry bed process. Summary of the Invention

[0004] The purpose of the utility model is to provide a slurry bed hydrogenation reactor for producing hydrogen peroxide by the anthraquinone method. This reactor is suitable for gas-liquid-solid three-phase reactions, can achieve good degassing and solid-liquid separation effects, and is beneficial to reducing raw material consumption. It should be noted that the diameter or radius involved in concepts such as diameter and height-diameter ratio in the utility model refers to the inner diameter.

[0005] To solve the above technical problems, the slurry bed hydrogenation reactor of the present utility model comprises a hydrogenation reactor, a recycle gas condenser and a degassing tank. The hydrogenation reactor is a vertical reactor, which includes a straight cylinder section at the bottom and an enlarged section located above the straight cylinder section. Preferably, the enlarged section includes a connecting section that is gradually expanded and connected to the straight cylinder section; a working liquid feed distributor and a hydrogen feed distributor are provided in the straight cylinder section; a riser is provided inside the hydrogenation reactor. The riser has the same diameter as the straight cylinder section, and there is a notch between the bottom of the riser and the top of the straight cylinder section. The upper part of the riser is lower than the liquid level of the reactor, and the upper part is an overflow area. The annulus between the riser and the enlarged section is a discharging and static area. A discharging baffle is provided at the discharging outlet of the static area. The discharging baffle is an annular structure, which includes a lower columnar section and a trumpet section located at the top of the columnar section. The upper end of the trumpet section is connected to the inner wall of the enlarged section, and a gap for the working liquid to pass through is provided at the lower end of the columnar section; the discharging baffle and the enlarged section enclose a discharging area, and the discharging area is connected to a discharging pipe; the discharging pipe is connected to the degassing tank. Two connecting pipes are provided at the top of the degassing tank to communicate with the upper part of the enlarged section, which are a gas phase balance pipe and a gas-liquid balance pipe from top to bottom in sequence. The top of the hydrogenation reactor is connected to the recycle gas condenser.

[0006] Specifically, the recycle gas condenser at the top of the slurry bed hydrogenation reactor is one of a shell and tube heat exchanger, a finned heat exchanger, and a plate heat exchanger.

[0007] Specifically, the diameter ratio of the riser of the slurry bed hydrogenation reactor to the upper enlarged section of the reactor is 0.5:1 to 0.8:1.

[0008] Specifically, the height-diameter ratio of the riser of the slurry bed hydrogenation reactor is 2:1 to 20:1.

[0009] Specifically, the ratio of the height of the gap between the riser of the slurry bed hydrogenation reactor and the lower straight cylinder of the reactor to the diameter of the riser is 0.05:1 to 0.3:1.

[0010] Specifically, the ratio of the height difference between the top of the riser of the slurry bed hydrogenation reactor and the liquid level of the reactor to the diameter of the riser is 0.5:1 to 1:1.

[0011] Specifically, the ratio of the cross-sectional area of the discharging area of the slurry bed hydrogenation reactor to the cross-sectional area of the upper enlarged section of the reactor (excluding the gradually expanded section) is 0.02:1 to 0.1:1.

[0012] Specifically, the diameter ratio of the degassing tank at the outlet of the slurry bed hydrogenation reactor to the diameter of the discharging pipe is 2:1 to 5:1.

[0013] Specifically, the height-diameter ratio of the degassing tank at the outlet of the slurry bed hydrogenation reactor is 2:1 to 8:1.

[0014] Specifically, the gas-liquid balance pipe of the slurry bed hydrogenation reactor and the outlet degassing tank is 500 to 2500 mm lower than the liquid level of the reactor.

[0015] The working fluid feed pipe of the slurry bed hydrogenation reactor enters from the middle and lower part of the reactor and extends to the bottom of the reactor. A working fluid feed distributor is provided at the bottom and is connected to the bottom flange of the reactor. The hydrogen feed distributor is one of an annular distributor and a tube bundle distributor.

[0016] The above slurry bed hydrogenation reactor is applied in the anthraquinone process for producing hydrogen peroxide. The working fluid, hydrogenation catalyst, recycled hydrogen and fresh hydrogen are fully mixed at the bottom of the slurry bed hydrogenation reactor and flow upward along the riser. Under the action of the hydrogenation catalyst, the anthraquinone in the working fluid reacts with hydrogen to obtain hydroanthraquinone. In the overflow area at the upper part of the riser, the recycled hydrogen and the reaction product hydrogenated liquid are separated. The recycled hydrogen rises and enters the recycle gas condenser. After removing the entrained aromatic hydrocarbons, it goes to the recycle gas compressor. The hydrogenated liquid in the overflow area overflows to the outer annulus of the riser, and catalyst sedimentation occurs in the settling area. The clear liquid of the hydrogenated liquid with a relatively low catalyst concentration enters the degassing tank from the side of the reactor. In the degassing tank, the entrained gas is further removed, and part of the hydrogenated liquid is discharged to the downstream system from the bottom of the degassing tank through the bottom circulation pipe and returns to the bottom of the reactor.

[0017] Specifically, for the slurry bed hydrogenation reactor in the anthraquinone process for producing hydrogen peroxide, its operating temperature is 40 - 80 °C, and the operating pressure is 0.05 - 0.50 MpaG. The working fluid is a mixed liquid of alkyl anthraquinone, heavy aromatic hydrocarbon and polar solvent. The alkyl anthraquinone is specifically at least one of 2-ethylanthraquinone, 2-butylanthraquinone and 2-pentylanthraquinone. The polar solvent is at least one of trioctyl phosphate, 2-methylcyclohexyl acetate, tetrabutylurea and diisobutyl methanol.

[0018] Compared with the prior art, the present utility model has at least the following beneficial effects:

[0019] The slurry bed hydrogenation reactor of the present utility model is provided with a recycle gas outlet recycle gas condenser at the top, which reduces the recycle gas liquid entrainment and lowers the solvent consumption.

[0020] In the overflow area at the upper part of the riser of the slurry bed hydrogenation reactor of the present utility model, the recycled hydrogen and the reaction product hydrogenated liquid are separated, reducing the gas holdup in the liquid.

[0021] The hydrogenated liquid in the overflow area of the slurry bed hydrogenation reactor of the present utility model overflows to the outer annulus of the riser, and catalyst sedimentation occurs in the settling area, reducing the solid content in the liquid.

[0022] The outlet of the slurry bed hydrogenation reactor of the present utility model is provided with a degassing tank, where the entrained gas is further removed, and the outer circulation returns to the bottom of the reactor from the bottom of the degassing tank. At the same time, a part of the hydrogenated liquid is discharged to the downstream system on the bottom circulation pipe, further reducing the gas holdup and solid content in the liquid. After two-stage degassing and solid separation, the gas holdup in the hydrogenated liquid is reduced by 40% - 90%, and the solid content is reduced by 20% - 80%.

[0023] The bottom of the slurry bed hydrogenation reactor of the present utility model is provided with a working fluid feed distributor and a hydrogen feed distributor, which can prevent the catalyst from depositing at the bottom of the reactor. Description of the Drawings

[0024] Figure 1 It is a schematic diagram of a slurry bed hydrogenation reactor for the production of hydrogen peroxide by the anthraquinone method.

[0025] In the figure: 1. Hydrogenation reactor, 2. Recycle gas condenser, 3. Degassing tank, 4. Gas riser, 5. Discharge baffle, 6. Working fluid feed distributor, 7. Hydrogen feed distributor, 8. Discharge pipe, 9. Gas-liquid balance pipe, 10. Gas-phase balance pipe, 11. Reaction zone, 12. Enlarged section, 13. Overflow zone, 14. Static zone, 15. Notch. Specific Embodiments

[0026] The present invention will be further described below in conjunction with embodiments.

[0027] Embodiment 1

[0028] As Figure 1 A slurry bed hydrogenation reactor for the production of hydrogen peroxide by the anthraquinone method as shown, including a hydrogenation reactor 1, a recycle gas condenser 2 and a degassing tank 3. The bottom of the hydrogenation reactor is provided with a working fluid feed distributor 6 and a hydrogen feed distributor 7. A gas riser 4 is provided in the middle of the hydrogenation reactor. The gas riser has the same diameter as the lower straight cylinder of the reactor and has a notch 15. The upper part of the gas riser is lower than the liquid level of the reactor, and the upper part is the overflow zone 13. The annulus between the gas riser 4 and the upper enlarged section 12 of the reactor is the discharge static zone 14. A discharge baffle 5 is provided at the discharge port of the static zone. The discharge pipe 8 is connected to the degassing tank 3. Two connecting pipes are provided at the top of the degassing tank 3, which are the gas-phase balance pipe 10 and the gas-liquid balance pipe 9 from top to bottom. The top of the hydrogenation reactor is connected to the recycle gas condenser 2.

[0029] The recycle gas condenser at the top recycle gas outlet of the slurry bed hydrogenation reactor is a shell-and-tube heat exchanger.

[0030] The diameter ratio of the gas riser of the slurry bed hydrogenation reactor to the upper enlarged section of the reactor is 0.6:1.

[0031] The height-diameter ratio of the gas riser of the slurry bed hydrogenation reactor is 9:1.

[0032] The ratio of the height of the riser tube of the slurry bed hydrogenation reactor to the notch of the lower straight cylinder of the reactor to the diameter of the riser tube is 0.15:1.

[0033] The height difference between the top of the riser tube of the slurry bed hydrogenation reactor and the liquid level of the reactor to the diameter of the riser tube is 0.6:1.

[0034] The ratio of the cross-sectional area of the discharge baffle in the static area of the slurry bed hydrogenation reactor to the cross-sectional area of the upper enlarged section of the reactor is 0.05:1.

[0035] The ratio of the diameter of the degassing tank at the outlet of the slurry bed hydrogenation reactor to the diameter of the discharge pipe is 3:1.

[0036] The height-diameter ratio of the degassing tank at the outlet of the slurry bed hydrogenation reactor is 4:1.

[0037] The gas-liquid equilibrium pipe of the slurry bed hydrogenation reactor and the degassing tank at the outlet is 2000 mm lower than the liquid level of the reactor.

[0038] The working fluid feed pipe of the slurry bed hydrogenation reactor enters from the middle and lower part of the reactor, extends to the bottom of the reactor, and a working fluid feed distributor is arranged at the bottom and connected to the bottom flange of the reactor.

[0039] The hydrogen feed distributor of the slurry bed hydrogenation reactor is an annular distributor.

[0040] The working fluid enters the bottom of the slurry bed hydrogenation reactor through the working fluid feed distributor, and hydrogen enters the bottom of the slurry bed hydrogenation reactor through the hydrogen feed distributor. In the bottom area of the slurry bed hydrogenation reactor, the working fluid, hydrogenation catalyst, recycled hydrogen, and fresh hydrogen are fully mixed and flow upward along the riser tube. Under the action of the hydrogenation catalyst, in the reaction zone, anthraquinone in the working fluid reacts with hydrogen to obtain hydroanthraquinone. In the upper overflow area of the riser tube, the recycled hydrogen and the reaction product hydrogenated liquid are separated. The recycled hydrogen rises and enters the recycle gas condenser, and after removing the entrained aromatic hydrocarbons, it goes to the recycle gas compressor. The hydrogenated liquid in the overflow area overflows to the outer annulus of the riser tube, and the catalyst settles in the static area. The clear liquid of the hydrogenated liquid with a relatively low catalyst concentration enters the degassing tank from the side of the reactor, further removes the entrained gas in the degassing tank, and returns to the bottom of the reactor through the outer circulation at the bottom of the degassing tank. At the same time, a part of the hydrogenated liquid is discharged to the downstream system through the bottom circulation pipe.

[0041] The operating temperature of the slurry bed hydrogenation reactor for producing hydrogen peroxide by the anthraquinone method is 40 - 80 °C, preferably 60 °C, and the operating pressure is 0.05 - 0.50 MpaG, preferably 0.1 MpaG.

[0042] For the slurry bed hydrogenation reactor for producing hydrogen peroxide by the anthraquinone method, the working fluid is a mixed liquid of alkyl anthraquinone, heavy aromatic hydrocarbon, and polar solvent, and the ratio of heavy aromatic hydrocarbon to polar solvent is 75:25.

[0043] The working fluid of the slurry bed hydrogenation reactor for producing hydrogen peroxide by the anthraquinone process, wherein the alkyl anthraquinone is 2-ethyl anthraquinone.

[0044] The working fluid of the slurry bed hydrogenation reactor for producing hydrogen peroxide by the anthraquinone process, wherein the polar solvent is trioctyl phosphate.

[0045] Example 2

[0046] Adopt Figure 1 The slurry bed hydrogenation reactor shown, wherein the heat exchange area of the circulating gas condenser at the top circulating gas outlet is 3 m2, the diameter of the riser is 600 mm, the diameter of the enlarged section is 1000 mm, the height of the riser is 5400 mm, the diameter of the degassing tank is 200 mm, and the height is 800 mm.

[0047] The feed rate of the working fluid is 8 m3 / h, the feed rate of hydrogen is 160 Nm3 / h, the reaction temperature is 60 °C, and the reaction pressure is 0.1 MPaG.

[0048] The solid content in the lower reaction zone of the slurry bed hydrogenation reactor is 10 g / L, and the solid content in the discharge pipe of the degassing tank is 3 g / L.

[0049] The gas holdup in the lower reaction zone of the slurry bed hydrogenation reactor is 18%, and the gas holdup in the degassing tank is 3%.

[0050] Data measurement

[0051] The above solid content is measured by the gravity method, and the gas holdup is measured by the differential pressure method.

[0052] The above are only the preferred embodiments of the present invention, and do not impose any limitations on the present invention. Any simple modifications, changes, and equivalent transformations made to the above embodiments according to the technical essence of the present invention still belong to the protection scope of the technical solution of the present invention.

Claims

1. A slurry bed hydrogenation reactor for producing hydrogen peroxide by the anthraquinone process, characterized in that: It includes a hydrogenation reactor (1), a recycle gas condenser (2) and a degassing tank (3); wherein the hydrogenation reactor (1) includes a straight cylinder section at the bottom and an enlarged section (12) at the upper part of the straight cylinder section; a working liquid feed distributor (6) and a hydrogen feed distributor (7) are arranged in the straight cylinder section; a riser (4) is arranged inside the hydrogenation reactor (1), the riser (4) has the same diameter as the straight cylinder section, and there is a notch (15) between the bottom of the riser (4) and the top of the straight cylinder section. The inside of the riser (4) forms a reaction zone (11), and the upper part is lower than the liquid level of the reactor, forming an overflow zone (13); the annulus between the riser (4) and the enlarged section is a discharge settling zone (14), and a discharge baffle (5) is arranged at the discharge port of the settling zone; the discharge baffle (5) is of an annular structure, including a lower columnar section and a trumpet section at the top of the columnar section. The upper end of the trumpet section is connected to the inner wall of the enlarged section, and a gap for the working liquid to pass through is arranged at the lower end of the columnar section; the discharge baffle (5) and the enlarged section enclose a discharge area, and the discharge area is connected to a discharge pipe (8); the discharge pipe (8) is connected to the degassing tank (3), and the top of the degassing tank (3) is connected to the enlarged section through two connecting pipes. The two connecting pipes are, from top to bottom, a gas phase balance pipe (10) and a gas-liquid balance pipe (9); the top of the hydrogenation reactor (1) is connected to the recycle gas condenser (2).

2. The slurry bed hydrogenation reactor for producing hydrogen peroxide by the anthraquinone process according to claim 1, wherein: The recycle gas condenser is one of a shell-and-tube heat exchanger, a finned heat exchanger, and a plate heat exchanger.

3. The slurry bed hydrogenation reactor for producing hydrogen peroxide by the anthraquinone process according to claim 1, characterized in that: The diameter ratio of the riser (4) to the enlarged section (12) is 0.5:1 to 0.8:

1.

4. The slurry bed hydrogenation reactor for producing hydrogen peroxide by the anthraquinone process according to claim 1, characterized in that: The height-diameter ratio of the riser (4) is 2:1 to 20:

1.

5. The slurry bed hydrogenation reactor for producing hydrogen peroxide by the anthraquinone process according to claim 1, characterized in that: The ratio of the height of the notch (15) to the diameter of the riser (4) is 0.05:1 to 0.3:

1.

6. The slurry bed hydrogenation reactor for producing hydrogen peroxide by the anthraquinone process according to claim 1, characterized in that: The ratio of the height difference between the top of the riser (4) and the liquid level of the reactor to the diameter of the riser (4) is 0.5:1 to 1:

1.

7. The slurry bed hydrogenation reactor for producing hydrogen peroxide by the anthraquinone process according to claim 1, characterized in that: The ratio of the cross-sectional area of the discharge area to the cross-sectional area of the enlarged section (12) is 0.02:1 to 0.1:

1.

8. The slurry bed hydrogenation reactor for producing hydrogen peroxide by the anthraquinone process according to claim 1, characterized in that: The diameter ratio of the degassing tank (3) to the discharge pipe (8) is 2:1 to 5:

1.

9. The slurry bed hydrogenation reactor for producing hydrogen peroxide by the anthraquinone process according to claim 1, characterized in that: The height-diameter ratio of the degassing tank (3) is 2:1 to 8:

1.

10. The slurry bed hydrogenation reactor for producing hydrogen peroxide by the anthraquinone process according to claim 1, characterized in that: The gas-liquid balance pipe (9) of the degassing tank (3) is 500 - 2500 mm lower than the liquid level of the reactor.

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