A reaction apparatus for reducing passivation of a bimetallic catalyst

Abstract

The application discloses a kind of reaction devices for reducing bimetallic catalyst passivation, specifically related to wastewater treatment equipment technical field, including reaction kettle, bimetallic catalyst packing piece, water inlet pipeline, water distribution pipe and circulation pipeline, water distribution pipe and bimetallic catalyst packing piece are placed in reaction kettle, water distribution pipe is wound outside bimetallic catalyst packing piece and is distributed in spiral shape, multiple water injection ports are arranged on the lateral wall of water distribution pipe, water inlet pipeline is connected and communicated with water distribution pipe by passing through reaction kettle, one end of circulation pipeline is connected and communicated with water inlet pipeline, the other end is connected and communicated with the bottom of reaction kettle, activated carbon powder and cathode metal powder are added in reaction kettle, activated carbon powder and cathode metal powder in reaction kettle flow into water inlet pipeline through circulation pipeline, and flow back to reaction kettle again through the water injection port of water distribution pipe.The application can guarantee catalyst reactivity, reduce anode passivation rate, protect the transfer channel of electron between anode and cathode, improve the probability of reduction reaction, and improve reaction efficiency.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment equipment technology, and in particular to a reaction device for reducing the passivation of bimetallic catalysts. Background Technology

[0002] The mainstream physicochemical reduction process on the market is iron-carbon micro-electrolysis technology. This technology is highly mature and widely used in engineering applications, but its application conditions are relatively harsh. It requires adjusting the pH of the influent to around 3, which wastes reagents and increases the salt content in the effluent, which does not conform to the current trend of increasingly strict salt control. In addition, the reaction process requires a large amount of aeration, resulting in high energy consumption.

[0003] The bimetallic catalytic reduction process, which has emerged in recent years, utilizes the potential difference between bimetals such as Fe-Cu, Fe-Pd, Al-Cu, and Fe-Ag. Through the principle of electrochemical corrosion, the anolyte dissolves, and the organic matter gains electrons on the cathode surface, undergoing a reduction reaction. This technology has a wide pH applicability, capable of carrying out reduction reactions in the range of 2–10, and does not require aeration. Considering economics and practicality, Fe-Cu bimetallic catalysts are currently the most researched. However, after reacting in water for a period of time, Fe-Cu bimetallic catalysts undergo passivation on the anode surface, leading to a decrease in reaction efficiency.

[0004] Passivated Fe-Cu bimetallic catalysts are generally treated by acid washing, which is not only time-consuming and labor-intensive, but also causes hydrogen atoms released during the acid washing process to easily diffuse into the metal, causing hydrogen embrittlement. This leads to a reduction in the toughness, ductility and plasticity of the metal, resulting in a significant decrease in the reaction activity of the catalyst after cleaning compared to before.

[0005] Furthermore, as electrochemical corrosion proceeds, the Fe-Cu bimetallic catalyst undergoes anode dissolution, and the gap between the two electrodes gradually widens, blocking electron transfer channels and reducing the chance of organic matter gaining electrons at the cathode and undergoing reduction reactions. Summary of the Invention

[0006] The purpose of this invention is to provide a reaction apparatus that reduces the passivation of bimetallic catalysts, thereby solving the problems existing in the prior art. This apparatus can ensure the catalytic activity, reduce the anode passivation rate, protect the electron transfer channel between the anode and cathode, increase the probability of reduction reaction, and improve reaction efficiency.

[0007] To achieve the above objectives, the present invention provides the following solution:

[0008] This invention provides a reaction apparatus for reducing the passivation of a bimetallic catalyst, comprising a reaction vessel, a bimetallic catalyst packing element, a water inlet pipe, a water distribution pipe, and a circulation pipe. Both the water distribution pipe and the bimetallic catalyst packing element are placed inside the reaction vessel. The water distribution pipe is spirally wound around the bimetallic catalyst packing element, and multiple spray nozzles are arranged on its side wall. The water inlet pipe passes through the reaction vessel and connects to the water distribution pipe. One end of the circulation pipe is connected to the water inlet pipe, and the other end is connected to the bottom of the reaction vessel. Activated carbon powder and cathode metal powder are added to the reaction vessel. The activated carbon powder and cathode metal powder in the reaction vessel can flow into the water inlet pipe through the circulation pipe, pass through the spray nozzles of the water distribution pipe, and then flow back to the reaction vessel.

[0009] Preferably, the reactor also includes a solid-liquid separator, which is fixedly placed at the top of the reactor interior. The solid-liquid separator is closer to the bimetallic catalyst packing than the reactor outlet. The solid-liquid separator is used to separate and treat water and solid materials.

[0010] Preferably, the plurality of water nozzles are evenly distributed on the water distribution pipe.

[0011] Preferably, each of the water spray nozzles is connected to a nozzle.

[0012] Preferably, the bimetallic catalyst packing includes a perforated cylinder and a bimetallic catalyst disposed within the perforated cylinder.

[0013] Preferably, an inlet pump is installed on the inlet pipeline, and the inlet pump is used to transport wastewater to the reaction vessel.

[0014] Preferably, a circulation pump is provided on the circulation pipeline, which is used to transport the treated water, the activated carbon powder and the cathode metal powder in the reactor to the water inlet pipeline.

[0015] Preferably, there are multiple bimetallic catalyst packing elements and multiple water distribution pipes, and the multiple bimetallic catalyst packing elements are evenly distributed in the reactor.

[0016] Preferably, it also includes a mixing distributor. The water inlet pipeline includes a main pipeline and multiple branch pipelines. The circulation pipeline is connected to and communicates with the main pipeline. The main pipeline is connected to and communicates with the mixing distributor. The mixing distributor is used to mix the mixture in the circulation pipeline and the main pipeline evenly. One end of each branch pipeline is connected to and communicates with the mixing distributor, and the other end is connected to and communicates with one of the water distribution pipes.

[0017] Preferably, the bottom of the reactor is funnel-shaped, and the bottom surface of the funnel-shaped bottom is connected and communicates with the circulation pipeline.

[0018] The present invention achieves the following technical effects compared to the prior art:

[0019] This invention provides a reaction apparatus for reducing the passivation of bimetallic catalysts. Activated carbon powder and cathode metal powder in the reactor can flow into the inlet water pipe through a circulation pipe, mix with wastewater in the inlet water pipe, and enter a spiral water distribution pipe wound around the bimetallic catalyst packing. The mixture is then sprayed out from the nozzles on the water distribution pipe. The activated carbon powder and cathode metal powder particles in the sprayed mixed water can wash away the surface of the bimetallic catalyst, removing precipitates and oxide films from the catalyst surface and slowing down the formation of oxide films on the metal surface, thus ensuring the catalyst's reactivity. Simultaneously, some activated carbon powder and cathode metal powder particles can remain in the gaps between the catalysts, filling the gaps caused by electrochemical corrosion, ensuring electron transfer channels between the anode and cathode, increasing the contact surface area between the anode and cathode, increasing the probability of reduction reaction, and improving reaction efficiency. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the reaction apparatus for reducing the passivation of bimetallic catalysts according to the present invention;

[0022] Figure 2 This is a top cross-sectional view of the reaction apparatus for reducing bimetallic catalyst passivation according to the present invention.

[0023] In the diagram: 1-Reaction vessel; 2-Bimetallic catalyst packing; 3-Inlet water pipe; 4-Water distribution pipe; 5-Circulation pipe; 6-Solid-liquid separator; 7-Fe shavings; 8-Cu shavings; 9-Outlet; 10-Funnel-shaped bottom; 11-Circulation pump; 12-Inlet water pump; 13-Mixer distributor; 14-Nozzle; 15-Perforated cylinder. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] The purpose of this invention is to provide a reaction apparatus that reduces the passivation of bimetallic catalysts, thereby solving the problems existing in the prior art. This apparatus can ensure the catalytic activity, reduce the anode passivation rate, protect the electron transfer channel between the anode and cathode, increase the probability of reduction reaction, and improve reaction efficiency.

[0026] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] This invention provides a reaction apparatus for reducing the passivation of bimetallic catalysts, such as... Figure 1-2 As shown, the reactor includes a reactor 1, a bimetallic catalyst packing 2, a water inlet pipe 3, a water distribution pipe 4, and a circulation pipe 5. The water distribution pipe 4 and the bimetallic catalyst packing 2 are both placed inside the reactor 1. The water distribution pipe 4 is wound around the bimetallic catalyst packing 2 in a spiral shape. Multiple water spray nozzles are arranged on the side wall of the water distribution pipe 4. The water inlet pipe 3 passes through the reactor 1 and is connected to the water distribution pipe 4. One end of the circulation pipe 5 is connected to the water inlet pipe 3 and the other end is connected to the bottom of the reactor 1. Activated carbon powder and cathode metal powder are added to the reactor 1. The activated carbon powder and cathode metal powder in the reactor 1 can flow into the water inlet pipe 3 through the circulation pipe 5, pass through the water spray nozzles of the water distribution pipe 4, and then flow back to the reactor 1. Activated carbon powder, cathode metal powder, and treated water in reactor 1 flow into inlet pipe 3 through circulation pipe 5, mix with wastewater in inlet pipe 3, and enter the spiral water distribution pipe 4 wound around the bimetallic catalyst packing 2. The treated water in circulation pipe 5 dilutes the pollutant concentration in the wastewater. The activated carbon powder and cathode metal powder particles in the sprayed mixed water wash the surface of the bimetallic catalyst, removing precipitates and oxide films, and slowing down the formation of oxide films on the metal surface, thus ensuring catalyst activity. Simultaneously, some activated carbon powder and cathode metal powder particles remain in the gaps between the catalysts, filling the gaps caused by electrochemical corrosion, ensuring electron transfer channels between the anode and cathode, and increasing the contact surface area between the anode and cathode. The activated carbon powder particles circulate around the catalyst, adsorbing organic matter onto the cathode surface, making it easier for the cathode to gain electrons, increasing the probability of reduction reactions, and improving reaction efficiency. The cathode metal in the cathode metal powder is the cathode metal in the bimetallic catalyst; for example, if the bimetallic catalyst is an Fe-Cu catalyst, the cathode metal powder is copper powder.

[0028] In a further preferred embodiment of the present invention, the reaction apparatus for reducing the passivation of the bimetallic catalyst further includes a solid-liquid separator 6. The solid-liquid separator 6 is fixedly placed at the top of the inside of the reaction vessel 1. The solid-liquid separator 6 is closer to the bimetallic catalyst packing 2 than the outlet 9 of the reaction vessel 1. The solid-liquid separator 6 is used to separate the treated water and solid materials. After the activated carbon powder and cathode metal powder particles in the reaction vessel 1 reach the top of the reaction vessel 1 with the water flow, they fall back to the lower part of the reactor due to the blocking and separation by the solid-liquid separator 6. The treated water flows out of the reaction vessel 1 from the outlet 9 at the top of the reaction vessel 1. The solid-liquid separator 6 can realize the separation of the solids of activated carbon powder and cathode metal powder from water, avoiding the loss of activated carbon powder and cathode metal powder. Preferably, the solid-liquid separator 6 is detachably connected to the reactor 1 via a pull rod and a Z-shaped plate. The solid-liquid separator 6 is placed on a boss at the top of the reactor 1. One end of the pull rod is threadedly connected to a nut on the boss, and the other end of the pull rod is fixedly connected to one plane of the Z-shaped plate. The other plane of the Z-shaped plate presses against the side of the solid-liquid separator 6 away from the boss at the top of the reactor 1. The Z-shaped plate applies pressure to the solid-liquid separator 6 to prevent it from shaking in the reactor 1. When it is necessary to disassemble the solid-liquid separator 6, the pull rod is rotated to separate the pull rod from the nut, and the Z-shaped plate no longer applies pressure to the solid-liquid separator 6, thereby facilitating the replacement of the solid-liquid separator 6.

[0029] In a further preferred embodiment of the present invention, multiple water nozzles are evenly distributed on the water distribution pipe 4, and each water nozzle is connected to a nozzle 14. Preferably, the nozzle 14 is a rotatable high-pressure nozzle 14, and the water flow is vortex-shaped, which can spray the catalyst in all directions and improve the removal efficiency of precipitates and oxide films on the catalyst surface.

[0030] In a further preferred embodiment of the present invention, the bimetallic catalyst packing 2 includes a perforated cylindrical body 15 and a bimetallic catalyst placed inside the perforated cylindrical body 15. For the Fe-Cu catalyst packing, the perforated cylindrical body 15 contains an Fe-Cu catalyst. Preferably, the Fe-Cu catalyst is Fe shavings 7 and Cu shavings 8. The relatively loose structure of Fe shavings 7 and Cu shavings 8 can ensure the flow of water inside the catalyst and reduce the probability of passivation. When the catalyst anode is worn down, copper powder can increase the contact area between the cathode and the anode, thereby ensuring the reaction efficiency. When the wastewater treatment effect verification shows that the catalyst anode is severely worn down and the catalytic reduction efficiency decreases significantly, the catalyst needs to be replaced. At this time, the solid-liquid separator 6 needs to be disassembled first, and then the bimetallic catalyst packing 2 is replaced by hoisting. The Fe-Cu catalyst is placed inside the perforated cylindrical body 15 for easy replacement, and the replaced cathode Cu catalyst can be recycled and placed back into the new perforated cylindrical body 15, reducing costs.

[0031] In a further preferred embodiment of the present invention, an inlet pump 12 is provided on the inlet pipe 3, which is used to transport wastewater to the reactor 1, and a circulation pump 11 is provided on the circulation pipe 5, which is used to transport the treated water, activated carbon powder and cathode metal powder in the reactor 1 to the inlet pipe 3.

[0032] In a further preferred embodiment of the present invention, the number of bimetallic catalyst packing elements 2 and water distribution pipes 4 is multiple, and the multiple bimetallic catalyst packing elements 2 are evenly distributed in the reaction vessel 1, which can improve the reaction efficiency.

[0033] In a further preferred embodiment of the present invention, the reaction apparatus for reducing the passivation of the bimetallic catalyst further includes a mixing distributor 13. The water inlet pipe 3 includes a main pipe and multiple branch pipes. The circulation pipe 5 is connected to and communicates with the main pipe. The main pipe is connected to and communicates with the mixing distributor 13. The mixing distributor 13 is used to mix the mixture in the circulation pipe 5 and the main pipe evenly. One end of each branch pipe is connected to and communicates with the mixing distributor 13, and the other end is connected to and communicates with a water distribution pipe 4. Connecting and communicating each branch pipe with the mixing distributor 13 can save manufacturing costs, and the water flow rate of each branch pipe is the same, which facilitates the adjustment of the fluid flow rate.

[0034] In a further preferred embodiment of the present invention, the bottom of the reactor 1 is a funnel-shaped bottom 10, the bottom surface of which is connected to and communicates with the circulation pipeline 5. The funnel-shaped bottom 10 facilitates the collection of activated carbon powder and cathode metal powder particles, improves circulation efficiency, and facilitates the collection and discharge of waste residue.

[0035] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A reaction apparatus for reducing the passivation of bimetallic catalysts, characterized in that: The system includes a reaction vessel, a bimetallic catalyst packing element, an inlet pipe, a distribution pipe, and a circulation pipe. Both the distribution pipe and the bimetallic catalyst packing element are placed inside the reaction vessel. The distribution pipe is spirally wound around the bimetallic catalyst packing element, and multiple spray nozzles are arranged on its side wall. The inlet pipe passes through the reaction vessel and connects to the distribution pipe. One end of the circulation pipe is connected to the inlet pipe, and the other end is connected to the bottom of the reaction vessel. Activated carbon powder and cathode metal powder are added to the reaction vessel. The cathode metal in the cathode metal powder is the cathode metal of the bimetallic catalyst. The activated carbon powder and cathode metal powder in the reaction vessel can flow into the inlet pipe through the circulation pipe, pass through the spray nozzles of the distribution pipe, and then flow back to the reaction vessel.

2. The reaction apparatus for reducing bimetallic catalyst passivation according to claim 1, characterized in that: It also includes a solid-liquid separator, which is fixedly placed at the top of the inside of the reactor. The solid-liquid separator is closer to the bimetallic catalyst packing than the outlet of the reactor. The solid-liquid separator is used to separate and treat water and solid materials.

3. The reaction apparatus for reducing bimetallic catalyst passivation according to claim 1, characterized in that: The multiple spray nozzles are evenly distributed on the water distribution pipe.

4. The reaction apparatus for reducing bimetallic catalyst passivation according to claim 3, characterized in that: Each of the aforementioned water spray nozzles is connected to a nozzle.

5. The reaction apparatus for reducing bimetallic catalyst passivation according to claim 1, characterized in that: The bimetallic catalyst packing includes a perforated cylindrical body and a bimetallic catalyst placed inside the perforated cylindrical body.

6. The reaction apparatus for reducing bimetallic catalyst passivation according to claim 1, characterized in that: An inlet pump is installed on the inlet pipeline, which is used to transport wastewater to the reaction vessel.

7. The reaction apparatus for reducing bimetallic catalyst passivation according to claim 1, characterized in that: A circulation pump is installed on the circulation pipeline, which is used to transport the treated water, activated carbon powder and cathode metal powder in the reactor to the water inlet pipeline.

8. The reaction apparatus for reducing bimetallic catalyst passivation according to claim 5, characterized in that: The number of bimetallic catalyst packing elements and water distribution pipes is multiple, and the multiple bimetallic catalyst packing elements are evenly distributed in the reactor.

9. The reaction apparatus for reducing bimetallic catalyst passivation according to claim 8, characterized in that: It also includes a mixing distributor. The water inlet pipeline includes a main pipeline and multiple branch pipelines. The circulation pipeline is connected to and communicates with the main pipeline. The main pipeline is connected to and communicates with the mixing distributor. The mixing distributor is used to mix the mixture in the circulation pipeline and the main pipeline evenly. One end of each branch pipeline is connected to and communicates with the mixing distributor, and the other end is connected to and communicates with one of the water distribution pipes.

10. The reaction apparatus for reducing bimetallic catalyst passivation according to claim 1, characterized in that: The bottom of the reactor is funnel-shaped, and the bottom surface of the funnel-shaped bottom is connected to and communicates with the circulation pipeline.

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