A system and method for rapid and efficient decomposition of ammonia to produce hydrogen by plasma catalysis

Abstract

The present invention discloses a system and method for realizing rapid and efficient decomposition of ammonia to produce hydrogen through plasma catalysis. Ammonia enters a normal-pressure arc temperature plasma reactor to form a rotating airflow, which is ionized into a highly active plasma under high-voltage electric drive. Driven by the rotating airflow and the reactor's tapered mouth, a large-area three-dimensional plasma jet is formed. The jet gas flows upward into the coaxial upper catalytic zone, and then flows downward into the coaxial outer catalytic zone due to the wall restriction, reacting with the catalyst to produce hydrogen, and the reacted gas flows out from the lower gas guide hole. Ammonia is first activated and pre-decomposed in the arc temperature plasma zone, and then decomposed for the second time in the coaxial catalytic zone. The heat of the warm plasma zone acts directly on the catalytic zone without the need for external heating. The overall structure is a coaxial integrated configuration of the warm plasma zone and the catalytic zone, which improves the waste heat utilization rate and reaction energy efficiency. The system of the present invention has a simple and compact structure, can be distributed and flexibly supply hydrogen, has a high energy density, and can be directly driven by wind and solar green electricity.

Description

Technical Field

[0001] The present invention belongs to the field of efficient utilization of zero-carbon fuels, and relates to a system and method for achieving rapid and efficient decomposition of ammonia to produce hydrogen through plasma catalysis. Background Art

[0002] Global climate and environmental changes have posed severe challenges to human economic and social development. The concentration of CO2 in the atmosphere has reached an unprecedented level. Low-carbonization or even zero-carbonization has become an inevitable trend in global development.

[0003] In the field of energy applications, ammonia is playing an increasingly important role. On the one hand, ammonia is regarded as a highly promising zero-carbon fuel. In the context of global response to climate change and reduction of carbon emissions, its combustion process does not produce carbon dioxide, but only nitrogen and water, which is environmentally friendly and provides a feasible way to achieve the goal of carbon neutrality. On the other hand, ammonia is also an excellent hydrogen carrier. Although hydrogen is efficient, clean and has high energy density, its storage and transportation have always been difficult. Ammonia is liquid at room temperature and pressure, which is easy to store and transport. Storing and transporting hydrogen in the form of ammonia can greatly reduce costs and improve supply stability. The emergence of ammonia provides an innovative solution to the problem of hydrogen storage and transportation, opening up new avenues for the widespread application of hydrogen. In the future, with the continuous advancement of technology, ammonia is expected to play a greater role in the energy field and make important contributions to achieving the goal of sustainable development.

[0004] Significant progress has been made in the research of ammonia decomposition to produce hydrogen using thermal catalysis as experimental conditions. However, its startup time is slow (up to several hours), requiring catalyst preheating, and the device structure is relatively complex and the investment cost is high, making it difficult to meet the demand for rapid and flexible in-situ hydrogen supply. The temperature conditions for thermal catalytic ammonia decomposition to produce hydrogen are relatively high. Generally speaking, complete conversion can only be achieved at around 800K.

[0005] Research on plasma ammonia decomposition hydrogen production technology using electrical energy as a driving force mainly focuses on the fields of dielectric barrier discharge, microwave discharge, and sliding arc discharge. Although these low-temperature plasma electron energies are relatively high (e.g., 1-10 eV, about 10 4 ~10 5 ℃), has good chemical selectivity, but its gas processing capacity is small, which cannot meet the needs of large-flux, fast and efficient hydrogen production. In addition, the heat loss in the warm plasma zone is large, and the waste heat recovery and utilization capacity is weak, which leads to a significant reduction in the energy efficiency of hydrogen production from ammonia decomposition.

[0006] Therefore, there is an urgent need for a system and method that can simultaneously solve the above-mentioned problems, realize the rapid and efficient decomposition of ammonia to produce hydrogen, meet the requirements of high processing capacity and efficient heat recovery capacity, and match the operating conditions of fast combustion speed and low ignition energy. This will greatly enhance the application prospects of ammonia as a zero-carbon alternative fuel and provide a practical idea for the transformation of energy structure. Summary of the Invention

[0007] The purpose of the present invention is to address the deficiencies of the existing technology and provide a system and method for the rapid and efficient decomposition of ammonia to produce hydrogen by plasma catalysis, which has a compact structure, high energy efficiency and a large gas processing capacity.

[0008] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0009] According to a first aspect of the present specification, there is provided a system for achieving rapid and efficient decomposition of ammonia to produce hydrogen through plasma catalysis, the system comprising a power supply device, a flow control device, an ammonia supply device, and an arc temperature plasma reactor;

[0010] The power supply device is used to supply power to the arc temperature plasma reactor; the ammonia supply device is used to provide gaseous pure ammonia; the flow control device is used to control the outlet flow of the ammonia supply device;

[0011] The arc temperature plasma reactor comprises a metal connecting flange, a metal upper cover flange, a metal lower cover flange, an alumina insulator, a high voltage electrode, a rotating deflector, a metal inner electrode, a metal outer electrode and a quartz tube;

[0012] The outer side of the metal connecting flange is provided with a raw ammonia gas inlet and a low-pressure electrode; the upper and lower parts of the metal connecting flange are respectively fastened to a metal upper cover flange and a metal lower cover flange;

[0013] The quartz tube has an air outlet at the top and a circular base at the bottom, which is embedded in the groove of the metal upper cover flange. The outermost layer of the quartz tube is provided with a cylindrical alumina outer plate with an open bottom, and the innermost layer coaxial with it is provided with a cylindrical alumina inner plate with upper and lower openings. A disc-shaped alumina porous air guide plate loaded with catalyst is provided above the alumina inner plate. The lower part of the alumina outer plate is evenly provided with air guide holes on the wall around it.

[0014] A warm plasma zone is formed between the metal outer electrode and the metal inner electrode, a coaxial upper catalytic zone is formed between the upper inner region of the alumina outer plate and the upper region of the alumina porous air guide plate, and a coaxial outer catalytic zone is formed between the lower inner region of the alumina outer plate, the lower region of the alumina porous air guide plate, and the outer region of the alumina inner plate; the warm plasma zone, the coaxial upper catalytic zone, and the coaxial outer catalytic zone are all coaxially integrated, and the coaxial upper catalytic zone and the coaxial outer catalytic zone are filled with catalyst;

[0015] The high voltage pole and the alumina insulator are coaxially arranged, and the metal inner electrode passes through the alumina insulator and is connected to the high voltage pole;

[0016] The center of the metal connecting flange is provided with a through hole with the same outer diameter as the rotating deflector, and the rotating deflector is embedded in the through hole; the central through hole of the rotating deflector is provided with a tapered opening from bottom to top;

[0017] The metal outer electrode is a cylindrical electrode, and the central through hole of the metal outer electrode is provided with a tapered opening from bottom to top, and the bottom diameter is the same as the diameter of the rotating deflector, and they are connected to each other; the alumina inner plate is sleeved on the outer wall surface of the metal outer electrode, so that the wall surfaces are tightly attached to each other and a gas jet space is left in the area above the metal outer electrode.

[0018] Furthermore, the power supply device adopts a DC power supply or a frequency-adjustable high-voltage AC power supply;

[0019] When a DC power supply is used, the low-voltage power line is connected to the low-voltage pole of the arc temperature plasma reactor, and the high-voltage power line is connected to the high-voltage pole of the arc temperature plasma reactor;

[0020] When a frequency-adjustable high-voltage AC power supply is used, the low-voltage power line is connected to the low-voltage pole of the arc temperature plasma reactor, and the high-voltage power line is connected to the high-voltage pole of the arc temperature plasma reactor. The time-varying voltage and current signals are transmitted to the digital display screen to detect and regulate the discharge power input to the arc temperature plasma reactor in real time.

[0021] Furthermore, the ammonia supply device provides gaseous pure ammonia, which directly enters the arc temperature plasma reactor to provide a discharge gas source, and the gas supply pipeline is provided with a pressure meter and a temperature meter for real-time monitoring of gas pressure and temperature status.

[0022] Furthermore, an annular graphite gasket is provided between the lower surface of the annular base of the quartz tube and the metal connecting flange, and an annular graphite gasket is provided between the alumina insulator and the metal connecting flange, and the graphite gasket is used for ammonia sealing operation.

[0023] Furthermore, a gap is provided between the high-voltage pole and the inner wall of the alumina insulator, and is sealed with a fluororubber gasket; the metal inner electrode is a cylindrical electrode, and a circular hole with the same diameter as the metal inner electrode is provided at the center of one end of the high-voltage pole, and the metal inner electrode is coaxially embedded in the circular hole and fixed with screws.

[0024] Furthermore, the outside of the quartz tube is provided with a heat-insulating material polyurethane to reduce heat loss.

[0025] Furthermore, the metal inner electrode is made of tungsten metal; and the catalyst is an inverse catalyst CeO2 / Ni.

[0026] Furthermore, a plurality of tangential ammonia inlets are provided on the outer side wall of the rotating deflector. Ammonia enters from the inlet of the rotating deflector and forms a rotating airflow through the action of the tapered port and the rotating deflector.

[0027] Furthermore, ammonia forms a rotating upward spiral airflow in the gap between the metal inner electrode and the metal outer electrode. At the same time, driven by high voltage electricity, the spiral airflow pushes the arc between the electrodes to rotate and rise. Under the action of the tapered mouth of the metal outer electrode, the warm plasma is ejected in the form of a jet. The heat generated in the warm plasma zone directly acts on the coaxial upper catalytic zone and the coaxial outer catalytic zone.

[0028] According to a second aspect of this specification, a method for rapidly and efficiently decomposing ammonia to produce hydrogen through plasma catalysis is provided. The method is implemented based on the system described in the first aspect, and the method comprises the following steps:

[0029] Step 1: Open the ammonia supply device and adjust the flow control device to pass the gas into the arc temperature plasma reactor;

[0030] Step 2: Turn on the power supply device to allow ammonia gas to enter the atmospheric pressure arc temperature plasma reactor along the tangential air inlet to form a rotating airflow. At the same time, driven by high voltage electricity, the gas is ionized to produce a plasma with high reactivity. The plasma forms a large-area three-dimensional plasma jet under the promotion of the rotating airflow and the tapered opening of the metal outer electrode. The jet gas flows upward from the outlet of the temperature plasma zone of the reactor into the coaxial upper catalytic zone. Due to the restriction of the wall boundary, the gas then flows downward in a turbulent flow state into the coaxial outer catalytic zone, further reacting with the catalyst to produce hydrogen. The heat generated by the temperature plasma zone directly acts on the coaxial upper catalytic zone and the coaxial outer catalytic zone. No additional heating is required. The reacted gas flows out from the air guide hole below the cylindrical alumina inner plate, completing the secondary decomposition of ammonia.

[0031] The present invention has the following beneficial effects:

[0032] (1) The present invention adopts a coaxial and close-fitting configuration of the warm plasma reaction zone and the catalytic zone, realizing an integrated design of the reactor and the catalyst, which is small in size and compact in structure and easy to integrate and install.

[0033] (2) The warm plasma reaction zone and the catalytic zone are coupled in a coaxial configuration, which has better heat and mass transfer performance. The heat generated in the warm plasma reaction zone directly acts on the catalyst in the coaxial catalytic zone, thereby improving the waste heat recovery rate and energy efficiency, and can greatly improve the efficiency of the catalytic reaction.

[0034] (3) By adjusting the power, gas flow rate and other parameters of the arc temperature plasma reactor, the energy input density of pure ammonia is changed, thereby optimizing and controlling the H2 production and its proportion in the product.

[0035] (4) The high voltage pole and the inner electrode are connected in two sections, which makes it easy to replace the metal inner electrode of different materials and ensures that the metal inner electrode is in the center position inside the outer electrode, making it easy to integrate and install.

[0036] (5) Arc temperature plasma catalysis and synergistic efficiency enhance the efficiency of ammonia decomposition to produce hydrogen quickly and efficiently, and realize distributed and flexible hydrogen supply. In addition, arc temperature plasma has the advantages of rapid start and stop, high energy density, and can be directly driven by wind and solar green electricity, which can realize large-volume rapid and efficient conversion of ammonia, and is very suitable for mobile in-situ ammonia decomposition and hydrogen supply equipment.

[0037] (6) The catalytic zone uses a CeO2 / Ni catalyst with an inverse structure. The Ni metal is wrapped by the CeO2 carrier to form more interfacial active sites, which enhances the electronic metal-carrier interaction. Compared with other traditional ammonia decomposition catalysts, this inverse structure makes H species less likely to be poisoned, has better stability, and is more conducive to the adsorption of ammonia and the desorption of nitrogen and hydrogen. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A diagram showing the structure of a system for achieving rapid and efficient decomposition of ammonia to produce hydrogen through plasma catalysis in an embodiment of the present invention;

[0039] Figure 2 A schematic cross-sectional view of an arc temperature plasma reactor according to an embodiment of the present invention;

[0040] Figure 3 A schematic diagram of the internal cross-sectional structure of a high-voltage electrode provided in an embodiment of the present invention;

[0041] Figure 4 A schematic cross-sectional view of a rotating deflector and four-way tangential air inlets provided in an embodiment of the present invention;

[0042] Figure 5 A schematic structural diagram of a disc-shaped alumina porous air guide plate provided in an embodiment of the present invention;

[0043] In the figure: 1. Graphite gasket; 2. Metal outer electrode; 3. Thermal insulation material; 4. Coaxial outer catalytic zone; 5. High voltage pole; 6. Quartz tube; 7. Warm plasma zone; 8. Rotating deflector; 9. Tungsten metal inner electrode; 10. Alumina outer plate; 11. Alumina porous air guide plate; 12. Air guide holes; 13. Screws; 14. Alumina insulator; 15. Metal lower cover flange; 16. Metal connecting flange; 17. Low voltage pole; 18. Alumina inner plate; 19. Metal upper cover flange; 20. Coaxial upper catalytic zone; 101. Air inlet; 102. Air outlet. DETAILED DESCRIPTION

[0044] The specific embodiments of the present invention are described in detail below to facilitate understanding of the present invention by those skilled in the art. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the appended claims, these changes are obvious, and all inventions and creations utilizing the concepts of the present invention are protected.

[0045] like Figure 1-Figure 5 As shown, an embodiment of the present invention provides a system for rapidly and efficiently decomposing ammonia to produce hydrogen through plasma catalysis. The system includes a power supply device, a flow control device, an ammonia supply device, and an arc temperature plasma reactor.

[0046] The power supply device uses a direct current (DC) power supply or a frequency-adjustable high-voltage alternating current (AC) power supply to power the arc temperature plasma reactor. In a specific implementation, when a DC power supply is used, the low-voltage power line is connected to the low-voltage terminal 17 of the arc temperature plasma reactor, and the high-voltage power line is connected to the high-voltage terminal 5 of the arc temperature plasma reactor. When a frequency-adjustable high-voltage AC power supply is used, the low-voltage power line is connected to the low-voltage terminal 17 of the arc temperature plasma reactor, and the high-voltage power line is connected to the high-voltage terminal 5 of the arc temperature plasma reactor. Time-varying voltage and current signals are transmitted to a digital display screen to monitor and control the discharge power input to the arc temperature plasma reactor in real time.

[0047] The flow control device adopts a mass flow control instrument dedicated to ammonia and with a large range, which is used to control the outlet flow of the ammonia supply device.

[0048] The ammonia supply device provides gaseous pure ammonia, which directly enters the arc temperature plasma reactor to provide a discharge gas source. The gas supply pipelines are equipped with pressure instruments and temperature instruments to monitor the gas pressure and temperature in real time.

[0049] like Figure 2As shown, the warm plasma zone 7, the coaxial upper catalytic zone 20 and the coaxial outer catalytic zone 4 of the arc warm plasma reactor are all coaxially integrated, and the coaxial upper catalytic zone 20 and the coaxial outer catalytic zone 4 are both filled with catalysts for ammonia decomposition.

[0050] Taking the reversed-phase catalyst CeO2 / Ni as an example, the reversed-phase catalyst CeO2 / Ni can be prepared by the following steps:

[0051] S1: Dissolve 1.85 g of cerium nitrate hexahydrate and 5.46 g of nickel nitrate hexahydrate in 25 mL of deionized water. Dissolve 2.01 g of sodium hydroxide in 25 mL of deionized water and transfer to an 80 °C oil bath.

[0052] S2: After vigorously stirring the above solution for 30 minutes, the metal salt solution was added dropwise to the sodium hydroxide solution and continued to stir in an 80°C oil bath for 2 hours;

[0053] S3: After washing the sample with water and ethanol, it was dried at 80 °C and allowed to stand for 12 h, and finally calcined at 400 °C for 2 h to obtain a CeO2 / Ni reverse phase catalyst sample;

[0054] In a specific implementation, before use, the sample was reduced with 30 Vol% H2 / Ar mixed gas (50 ml / min) at 500°C for 2 hours.

[0055] like Figure 2 As shown, the arc temperature plasma reactor includes a metal connecting flange 16, a metal upper cover flange 19, a metal lower cover flange 15, an alumina insulator 14, a high voltage pole 5, a rotating deflector 8, a tungsten metal inner electrode 9, a metal outer electrode 2, and a quartz tube 6.

[0056] The outer side of the metal connecting flange 16 is provided with a raw ammonia gas inlet 101 and a low-voltage pole 17; the low-voltage pole 17 is used to connect the low-voltage power line of the power supply device, and the high-voltage pole 5 is used to connect the high-voltage power line of the power supply device; the upper and lower parts of the metal connecting flange 16 are respectively provided with a metal upper cover flange 19 and a metal lower cover flange 15 of the same specifications, which are fastened to each other by screws; the top of the quartz tube 6 is provided with an air outlet 102, and the bottom of the quartz tube 6 has a circular base, which is embedded in the metal upper cover flange 1 9, a circular graphite gasket 1 is provided between the lower surface of the base and the metal connecting flange 16 for ammonia sealing operation; the outside of the quartz tube 6 is provided with a heat-insulating material 3 polyurethane, the outermost layer of the inner part is provided with a cylindrical alumina outer plate 10 with a bottom opening, and the innermost layer coaxial with it is provided with a cylindrical alumina inner plate 18 with upper and lower openings, and a disc-shaped alumina porous air guide plate 11 loaded with catalyst is provided above the cylindrical alumina inner plate 18 with upper and lower openings. The structure of the disc-shaped alumina porous air guide plate 11 is as shown Figure 5As shown; the cylindrical alumina outer plate 10 with an open bottom has gas guide holes 12 uniformly opened on the surrounding walls at the lower portion thereof for guiding the gas after the reaction.

[0057] Furthermore, an arc is generated at the point where the distance between the metal outer electrode 2 and the tungsten metal inner electrode 9 is minimum, forming a warm plasma zone 7, and a coaxial upper catalytic zone 20 is formed between the upper inner region of the cylindrical alumina outer plate 10 with an opening at the bottom and the upper region of the disc-shaped alumina porous air guide plate 11, and a coaxial outer catalytic zone 4 is formed between the lower inner region 10 of the cylindrical alumina outer plate with an opening at the bottom, the lower region of the disc-shaped alumina porous air guide plate 11 and the outer region of the cylindrical alumina inner plate 18 with upper and lower openings.

[0058] Furthermore, if Figure 3 As shown, the high-voltage electrode 5 and the alumina insulator 14 are coaxially arranged, and a gap is provided between the high-voltage electrode 5 and the inner wall of the alumina insulator 14, and a fluororubber gasket is used for sealing; the tungsten metal inner electrode 9 is a cylindrical electrode, and a circular hole with the same diameter as the tungsten metal inner electrode 9 is provided at the center of one end of the high-voltage electrode 5. The tungsten metal inner electrode 9 is coaxially embedded in the circular hole and fixed with a screw 13.

[0059] Furthermore, a circular graphite gasket is provided between the alumina insulator 14 and the metal connecting flange 16 to perform ammonia sealing operation.

[0060] Furthermore, if Figure 4 As shown, a through hole with the same outer diameter as the rotating deflector 8 is provided at the center of the metal connecting flange 16, and the rotating deflector 8 is embedded in the through hole; the central through hole of the rotating deflector 8 is provided with a tapered opening from bottom to top, and four tangential ammonia air inlets 101 are evenly provided on the outer wall of the rotating deflector 8. Ammonia enters the rotating deflector from the tangential air inlets around the rotating deflector, and a rotating airflow is formed through the action of the tapered opening and the rotating deflector 8.

[0061] The metal outer electrode 2 is a cylindrical electrode, connected to the metal upper cover flange 19 by internal and external threads. The central through-hole of the metal outer electrode 2 is provided with a tapered opening from bottom to top, and the bottom diameter is the same as that of the rotating deflector 8, and they are connected to each other. Ammonia gas forms a spiral airflow in the gap between the tungsten metal inner electrode 9 and the metal outer electrode 2, rotating and rising. Simultaneously, driven by the high voltage, the spiral airflow propels the arc between the electrodes to rotate and rise. Under the action of the tapered opening of the metal outer electrode 2, the warm plasma is ejected from the reactor in the form of a jet. The heat generated by the warm plasma zone 7 directly acts on the coaxial upper catalytic zone 20 and the coaxial outer catalytic zone 4, without the need for additional heating.

[0062] Furthermore, the exterior of the quartz tube 6 is wrapped with a polyurethane heat-insulating material 3 to reduce heat loss. The outermost layer of the quartz tube 6 is provided with a cylindrical alumina outer plate 10 with a bottom opening, and the innermost layer coaxially therewith is provided with a cylindrical alumina inner plate 18 with upper and lower openings. A disc-shaped alumina porous air guide plate 11 is provided above the upper and lower opening cylindrical alumina inner plate 18. The upper and lower opening cylindrical alumina inner plate 18 is sleeved onto the outer wall of the metal outer electrode 2, ensuring that the walls are tightly attached to each other and leaving a certain amount of gas jet space in the area above the metal outer electrode 2. In specific implementation, the disc-shaped alumina porous air guide plate 11 is placed above the upper and lower opening cylindrical alumina inner plate 18 to limit its position and prevent it from sliding.

[0063] During specific implementation, ammonia gas first enters the interior of the atmospheric pressure arc warm plasma reactor along four tangential air inlets to form a rotating airflow. Simultaneously, driven by high voltage electricity, the gas is ionized to produce a highly reactive plasma. Driven by the rotating airflow and the tapered opening of the metal outer electrode, the plasma forms a large-area three-dimensional plasma jet. The jet gas flows upward from the outlet of the warm plasma zone 7 of the reactor into the coaxial upper catalytic zone 20. Due to the restriction of the wall boundary, the gas then flows downward in a turbulent flow state into the coaxial outer catalytic zone 4, further reacting with the catalyst to produce hydrogen. The reacted gas flows out from the air guide holes 12 below the cylindrical alumina inner plate with an opening at the bottom, and then flows upward and out from the outlet 102 at the top of the quartz tube 6. During this process, the heat generated by the warm plasma zone 7 directly acts on the coaxial upper catalytic zone 20 and the coaxial outer catalytic zone 4, without the need for additional heating.

[0064] The present invention also provides a method for rapidly and efficiently decomposing ammonia to produce hydrogen through plasma catalysis, comprising the following steps:

[0065] Step 1: Open the ammonia supply device, adjust the flow control device to control the gas flow rate at 1-5 L / min, and pass the gas into the arc temperature plasma reactor;

[0066] Step 2: Turn on the power supply device to allow the ammonia gas to enter the atmospheric pressure arc temperature plasma reactor along the four tangential air inlets to form a rotating airflow. At the same time, driven by high voltage electricity, the gas is ionized to produce a plasma with high reactivity. The plasma forms a large-area three-dimensional plasma jet under the promotion of the rotating airflow and the tapered opening of the metal outer electrode. The reactor power and air inlet flow rate are flexibly controlled to complete the pre-activation conversion of ammonia. The jet gas flows upward from the outlet of the temperature plasma zone of the reactor into the coaxial upper catalytic zone. Due to the restriction of the wall boundary, the gas then flows downward in a turbulent flow state into the coaxial outer catalytic zone, further reacting with the catalyst to produce hydrogen. The heat generated by the temperature plasma zone directly acts on the coaxial upper catalytic zone and the coaxial outer catalytic zone. No additional heating is required. The reacted gas flows out from the air guide hole below the cylindrical alumina inner plate to complete the secondary decomposition of ammonia.

[0067] The above description is only a preferred embodiment of the present invention. Although the present invention has been disclosed as a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can use the above disclosed methods and technical contents to make many possible changes and modifications to the technical solution of the present invention without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of protection of the technical solution of the present invention.

Claims

1. A system for rapidly and efficiently decomposing ammonia to produce hydrogen by plasma catalysis, characterized in that: The system includes a power supply device, a flow control device, an ammonia supply device and an arc temperature plasma reactor; The power supply device is used to supply power to the arc temperature plasma reactor; the ammonia supply device is used to provide gaseous pure ammonia; the flow control device is used to control the outlet flow of the ammonia supply device; The arc temperature plasma reactor comprises a metal connecting flange, a metal upper cover flange, a metal lower cover flange, an alumina insulator, a high voltage electrode, a rotating deflector, a metal inner electrode, a metal outer electrode and a quartz tube; The outer side of the metal connecting flange is provided with a raw ammonia gas inlet and a low-pressure electrode; the upper and lower parts of the metal connecting flange are respectively fastened to a metal upper cover flange and a metal lower cover flange; The quartz tube has an air outlet at the top and a circular base at the bottom, which is embedded in the groove of the metal upper cover flange. The outermost layer of the quartz tube is provided with a cylindrical alumina outer plate with an open bottom, and the innermost layer coaxial with it is provided with a cylindrical alumina inner plate with upper and lower openings. A disc-shaped alumina porous air guide plate loaded with catalyst is provided above the alumina inner plate. The lower part of the alumina outer plate is evenly provided with air guide holes on the wall around it. A warm plasma zone is formed between the metal outer electrode and the metal inner electrode, a coaxial upper catalytic zone is formed between the upper inner region of the alumina outer plate and the upper region of the alumina porous air guide plate, and a coaxial outer catalytic zone is formed between the lower inner region of the alumina outer plate, the lower region of the alumina porous air guide plate, and the outer region of the alumina inner plate; the warm plasma zone, the coaxial upper catalytic zone, and the coaxial outer catalytic zone are all coaxially integrated, and the coaxial upper catalytic zone and the coaxial outer catalytic zone are filled with catalyst; The high voltage pole and the alumina insulator are coaxially arranged, and the metal inner electrode passes through the alumina insulator and is connected to the high voltage pole; The center of the metal connecting flange is provided with a through hole with the same outer diameter as the rotating deflector, and the rotating deflector is embedded in the through hole; the central through hole of the rotating deflector is provided with a tapered opening from bottom to top; The metal outer electrode is a cylindrical electrode, and the central through hole of the metal outer electrode is provided with a tapered opening from bottom to top, and the bottom diameter is the same as the diameter of the rotating deflector, and they are connected to each other; the alumina inner plate is sleeved on the outer wall surface of the metal outer electrode, so that the wall surfaces are tightly attached to each other and a gas jet space is left in the area above the metal outer electrode.

2. The system according to claim 1, wherein: The power supply device adopts a DC power supply or a frequency-adjustable high-voltage AC power supply; When a DC power supply is used, the low-voltage power line is connected to the low-voltage pole of the arc temperature plasma reactor, and the high-voltage power line is connected to the high-voltage pole of the arc temperature plasma reactor; When a frequency-adjustable high-voltage AC power supply is used, the low-voltage power line is connected to the low-voltage pole of the arc temperature plasma reactor, and the high-voltage power line is connected to the high-voltage pole of the arc temperature plasma reactor. The time-varying voltage and current signals are transmitted to the digital display screen to detect and regulate the discharge power input to the arc temperature plasma reactor in real time.

3. The system according to claim 1, wherein: The ammonia supply device provides gaseous pure ammonia, which directly enters the arc temperature plasma reactor to provide a discharge gas source. The gas supply pipeline is provided with a pressure meter and a temperature meter to monitor the gas pressure and temperature status in real time.

4. The system according to claim 1, wherein: A circular graphite gasket is provided between the lower surface of the circular base of the quartz tube and the metal connecting flange, and a circular graphite gasket is provided between the alumina insulator and the metal connecting flange. The graphite gasket is used for ammonia sealing operation.

5. The system according to claim 1, wherein: A gap is provided between the high-voltage electrode and the inner wall of the alumina insulator, and is sealed with a fluororubber gasket; the metal inner electrode is a cylindrical electrode, and a circular hole with the same diameter as the metal inner electrode is provided at the center of one end of the high-voltage electrode. The metal inner electrode is coaxially embedded in the circular hole and fixed with screws.

6. The system according to claim 1, wherein: The exterior of the quartz tube is provided with heat-insulating polyurethane material to reduce heat loss.

7. The system according to claim 1, wherein: The metal inner electrode is made of tungsten metal; the catalyst is an inverse catalyst CeO2 / Ni.

8. The system according to claim 1, wherein: The outer side wall of the rotating deflector is provided with a plurality of tangential ammonia inlets. Ammonia enters from the inlets of the rotating deflector and forms a rotating airflow through the action of the tapered port and the rotating deflector.

9. The system according to claim 1, wherein: Ammonia forms a rotating upward spiral airflow in the gap between the metal inner electrode and the metal outer electrode. At the same time, driven by high voltage electricity, the spiral airflow pushes the arc between the electrodes to rotate and rise. Under the action of the tapered mouth of the metal outer electrode, the warm plasma is ejected in the form of a jet. The heat generated in the warm plasma zone directly acts on the coaxial upper catalytic zone and the coaxial outer catalytic zone.

10. A method for rapidly and efficiently decomposing ammonia to produce hydrogen by plasma catalysis, characterized in that: The method is implemented based on the system according to any one of claims 1 to 9, and comprises the following steps: Step 1: Open the ammonia supply device and adjust the flow control device to pass the gas into the arc temperature plasma reactor; Step 2: Turn on the power supply device to allow ammonia gas to enter the atmospheric pressure arc temperature plasma reactor along the tangential air inlet to form a rotating airflow. At the same time, driven by high voltage electricity, the gas is ionized to produce a plasma with high reactivity. The plasma forms a large-area three-dimensional plasma jet under the promotion of the rotating airflow and the tapered opening of the metal outer electrode. The jet gas flows upward from the outlet of the temperature plasma zone of the reactor into the coaxial upper catalytic zone. Due to the restriction of the wall boundary, the gas then flows downward in a turbulent flow state into the coaxial outer catalytic zone, further reacting with the catalyst to produce hydrogen. The heat generated by the temperature plasma zone directly acts on the coaxial upper catalytic zone and the coaxial outer catalytic zone. No additional heating is required. The reacted gas flows out from the air guide hole below the cylindrical alumina inner plate, completing the secondary decomposition of ammonia.

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