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CN-117842935-B - System and method for producing hydrogen peroxide

CN117842935BCN 117842935 BCN117842935 BCN 117842935BCN-117842935-B

Abstract

The invention relates to the technical field of hydrogen peroxide, and discloses a system and a method for preparing hydrogen peroxide. The system comprises a hydrogenation unit, an oxidation unit and an extraction unit which are sequentially connected, wherein the hydrogenation unit comprises a fixed bed reactor, the fixed bed reactor comprises a reactor cylinder body, a liquid phase inlet, N gas phase inlets, a liquid phase outlet and a gas phase outlet which are sequentially arranged on the reactor cylinder body from bottom to top, N sections of catalyst beds and gas-liquid separation components which are sequentially arranged in the reactor cylinder body from bottom to top, N is a natural number and is more than or equal to 2, a gas distributor is arranged below each section of catalyst bed, the gas distributor is connected with the gas phase inlet, the gas-liquid separation components are divided into a two-phase region, a liquid phase region and a gas phase region, the liquid phase region is provided with the liquid phase outlet, and the gas phase region is provided with the gas phase outlet. The hydrogen peroxide prepared by the system can obviously improve hydrogenation efficiency and hydrogenation selectivity, has good safety, effectively improves hydrogenation reaction selectivity and device efficiency, and prolongs the service life of the catalyst.

Inventors

  • GAO GUOHUA
  • Tian yanan
  • YANG KEYONG

Assignees

  • 中国石油化工股份有限公司
  • 中石化石油化工科学研究院有限公司

Dates

Publication Date
20260505
Application Date
20220930

Claims (20)

  1. 1. A system for producing hydrogen peroxide, characterized in that, The system comprises a hydrogenation unit, an oxidation unit and an extraction unit which are sequentially connected, wherein: The hydrogenation unit is used for sequentially carrying out hydrogenation reaction and gas-liquid separation on the hydrogen-containing gas and the working solution to obtain hydrogenation solution and hydrogen-containing tail gas, wherein the hydrogenation solution is divided into solution A and solution B; the hydrogenation unit comprises a hydrogenation reactor, wherein the hydrogenation reactor is a fixed bed reactor, the hydrogenation reactor comprises a reactor cylinder body, a liquid phase inlet, N gas phase inlets, a liquid phase outlet and a gas phase outlet which are sequentially arranged on the reactor cylinder body from bottom to top, and N sections of catalyst beds and gas-liquid separation components which are sequentially arranged in the reactor cylinder body from bottom to top, wherein N is a natural number and N is more than or equal to 2, and the height-diameter ratio of the catalyst beds is 1:0.5-5; The gas distributor is arranged below each section of the catalyst bed layer and connected with the gas phase inlet, wherein the shortest distance d1 between the gas phase inlet and the lower surface of the catalyst bed layer is 0.1-1.5m, and the gas distributor is selected from an open pore pipe or a micropore element; The gas-liquid separation component is divided into a two-phase zone, a liquid-phase zone and a gas-phase zone, wherein the liquid-phase zone is provided with the liquid-phase outlet; the hydrogenation unit further comprises a regeneration reactor, wherein the regeneration reactor is communicated with a liquid phase outlet of the hydrogenation reactor and an inlet of the oxidation unit and is used for carrying out a regeneration reaction on the solution A to obtain regenerated hydrogenated solution; The oxidation unit is used for carrying out oxidation reaction on the solution B, the regenerated hydrogenation solution and the oxygen-containing gas to obtain oxidation solution; the extraction unit is used for extracting the oxidation liquid to obtain hydrogen peroxide solution and raffinate, and returning the raffinate to the hydrogenation unit.
  2. 2. The system of claim 1, wherein the number of segments of the catalyst bed is 2-8 segments; And/or the aperture of the open pore pipe is 0.5-12mm, and the aperture of the microporous element is 0.2-500 mu m; and/or a liquid distributor is arranged below each section of the catalyst bed layer, and the liquid distributor is arranged below the gas distributor.
  3. 3. The system of claim 2, wherein the number of segments of the catalyst bed is 3-5 segments.
  4. 4. The system of claim 1 or 2, wherein the catalyst bed has an aspect ratio of 1:0.8-3.
  5. 5. The system of claim 1 or 2, wherein the shortest distance d1 of the gas phase inlet from the lower surface of the catalyst bed is 0.2-0.8m.
  6. 6. The system of claim 2, wherein the open-pore tube has a pore size of 1-8mm.
  7. 7. The system of claim 2, wherein the microporous element has a pore size of 0.5-200 μm.
  8. 8. The system of claim 1, wherein the gas-liquid separation component comprises a separation component cartridge, and a baffle, overflow tube, and anti-collision baffle disposed within the separation component cartridge; The area formed by the overflow pipe and the anti-collision baffle is the two-phase area, the area formed by the baffle plate and the inner wall of the separator cylinder is the liquid-phase area, and the area formed by the anti-collision baffle and the inner wall of the separator cylinder is the gas-phase area; And/or the ratio of the inner diameters of the separation part cylinder and the reactor cylinder is 0.2-1.5:1; and/or the included angle alpha between the baffle plate and the separating part cylinder body is 45-90 degrees, and the included angle beta between the baffle plate and the overflow pipe is 90-145 degrees; And/or the inner diameter ratio of the overflow pipe and the separating part cylinder is 0.15-0.75:1; and/or the height ratio of the overflow pipe to the separating part cylinder is 0.2-0.95:1; And/or the anti-impact baffle is arranged above the overflow pipe; And/or, the impact-resistant baffle plate is in a conical structure.
  9. 9. The system of claim 8, wherein the ratio of the inner diameters of the separation member cylinder and the reactor cylinder is 0.5-1:1.
  10. 10. The system of claim 8, wherein the inner diameter ratio of the overflow tube and the separation member cylinder is 0.2-0.6:1.
  11. 11. The system of claim 8, wherein the height ratio of the overflow tube to the separation member cartridge is 0.5-0.8:1.
  12. 12. The system of claim 8, wherein the shortest distance of the lower edge of the impact shield from the upper end of the overflow tube is 0.3-1.2m.
  13. 13. The system of claim 12, wherein the shortest distance of the lower edge of the impact shield from the upper end of the overflow tube is 0.3-0.8m.
  14. 14. The system of claim 8, wherein the impingement baffle is of conical configuration and the included angle γ is 110 ° -145 °.
  15. 15. The system of any of claims 1-3, wherein the liquid phase inlet is disposed at a bottom of the reactor vessel; And/or, the gas phase outlet is connected with N gas phase inlets; And/or a gas flow controller is arranged on the pipeline of each gas phase inlet.
  16. 16. The system of claim 15, wherein the gas phase outlet is connected to N of the gas phase inlets, and a compressor is provided on a conduit connecting the gas phase outlet and gas phase inlet.
  17. 17. The system of claim 15, wherein a gas flow regulating valve is disposed on a conduit connecting the gas phase inlet and a gas flow controller, and the gas flow regulating valve is disposed between the gas phase inlet and the gas flow controller.
  18. 18. The system of any of claims 1-3, wherein the hydrogenation reactor further comprises (N-1) circulating liquid phase inlets connected to the liquid phase outlet, and the circulating liquid phase inlets are each independently disposed on the reactor vessel; and/or, from bottom to top, paragraph 2. An nth stage of the process, wherein, the circulating liquid phase inlet is independently arranged below each section of catalyst bed layer; And/or, from bottom to top, the (N-1) th said circulating liquid phase inlet is disposed below the nth said gas phase inlet; And/or the shortest distance d2 of the circulating liquid phase inlet to the lower part of the catalyst bed layer is 0.2-1.2m; And/or a first cooler is arranged on a pipeline connecting the circulating liquid phase inlet and the liquid phase outlet; And/or a liquid flow controller is further arranged on a pipeline connecting the circulating liquid phase inlet and the liquid phase outlet, and the liquid flow controller is arranged in front of the first cooler; And/or a liquid flow regulating valve is further arranged on a pipeline connecting the circulating liquid phase inlet and the liquid phase outlet, and the liquid flow regulating valve is arranged between the liquid flow controller and the circulating cooler.
  19. 19. The system of claim 18, wherein the shortest distance d2 of the circulating liquid phase inlet from below the catalyst bed is 0.3-0.8m.
  20. 20. A system according to any one of claims 1-3, wherein the top of the reactor vessel is provided with a pressure controller; and/or the liquid phase zone is provided with a liquid level controller.

Description

System and method for producing hydrogen peroxide Technical Field The invention relates to the technical field of hydrogen peroxide, in particular to a system and a method for preparing hydrogen peroxide. Background Hydrogen peroxide, also known as hydrogen peroxide, is a green chemical product, and has almost no pollution in the production and use processes, so that the hydrogen peroxide is called a clean chemical product, and is widely applied to industries such as chemical industry, papermaking, environmental protection, electronics, food, medicine, textile, mining industry, agricultural waste processing and the like as an oxidant, a bleaching agent, a disinfectant, a deoxidizer, a polymer initiator and a crosslinking agent. The anthraquinone process is the predominant process for the production of industrial hydrogen peroxide, with more than 99% of the global industrial hydrogen peroxide being produced by the anthraquinone process on a production scale. The anthraquinone process includes the steps of hydrogenation, oxidation, extraction, post-treatment of circulating working liquid, etc. The efficiency of anthraquinone hydrogenation directly affects the efficiency and product concentration of the whole production device. The "hydrogen efficiency" is typically used to characterize the anthraquinone hydrogenation efficiency, i.e., the grams of hydrogen peroxide per liter of hydrogenation reaction liquid (referred to as "hydrogenation liquid"). The domestic hydrogen peroxide production technology adopts a trickle bed hydrogenation process, the hydrogen efficiency is only 6-7 g/L generally, and the production efficiency of the device is low. The reason for this is mainly because hydrogen in the trickle bed reactor is used as a continuous phase, and a reaction liquid (called a working liquid) is used as a disperse phase, so that bias flow or channeling is easy to generate in the bed layer, thereby causing local excessive hydrogenation and local hot spots in the bed layer, and the bed layer has higher temperature rise, so that the defects are mainly: (1) The catalyst is easy to deactivate, and must be regenerated or replaced periodically, so that not only is steam consumed, but also working fluid and noble metal of the catalyst are lost. In the current domestic fixed bed hydrogenation process, the catalyst needs to be regenerated once with steam for 3-6 months. (2) In order to prevent excessive hydrogenation, the anthraquinone conversion is usually controlled at a relatively low level (30-40%), the hydrogen efficiency is limited, and the device efficiency is low. Compared with the same-scale device with high hydrogen efficiency, the circulating working fluid quantity is larger, and the power consumption of the pump is larger. (3) The working solution is easy to degrade, a large amount of activated alumina is industrially adopted to continuously regenerate the circulating working solution, the activated alumina needs to be frequently replaced, a large amount of solid dangerous waste is generated, and the working solution is lost. For example, 5kg of activated alumina is consumed to produce 1 ton of hydrogen peroxide product, resulting in a loss of 3kg of working fluid. (4) The device has poor safety, and needs to adopt a potassium carbonate drying tower to remove saturated moisture in the circulating working solution, thereby strengthening the regeneration of the working solution. The hydrogen peroxide is decomposed when meeting alkali, so that the potential safety hazard is serious. The hydrogen peroxide device has safety accidents every year, and 80% of safety accidents are caused by alkali stringing to an oxidation and extraction unit of the system. CN104843648a discloses a fixed bed hydrogenation reaction system for preparing hydrogen peroxide by anthraquinone method, the top of the hydrogenation column is equipped with spray head as working liquid inlet, and hydrogen gas also enters from the top of the reactor through distributor. In order to improve the uniformity of gas-liquid distribution in the reactor and reduce the temperature rise of the reactor bed, the hydrogenation reaction system provided by the patent is provided with a heat exchanger layer and a gas-liquid distributor between catalyst layers. The reactor provided by the patent has a complex structure, the height of the reactor is increased, and the internal heat collector has the risk of losing the catalyst caused by leakage. CN1108984C discloses a method for regenerating working fluid, at least a portion of unreduced working fluid is contacted with a catalyst mainly containing gamma-alumina at 40-150 ℃ to effect regeneration of byproducts in the working fluid. The working solution is regenerated and placed in 'unreduced', namely before hydrogenation, the working solution is contacted with the gamma-alumina catalyst at the temperature of 40-150 ℃, so that secondary side reactions can be caused besides the regeneration effect on hydrogenation