System and method for rapidly and efficiently decomposing ammonia to produce hydrogen through cooperation of plasma catalysis

Abstract

The invention discloses a system and a method for rapidly and efficiently decomposing ammonia to produce hydrogen through cooperation of plasma catalysis. Ammonia gas enters the normal-pressure arc temperature plasma reactor to form rotating gas flow, is ionized into high-activity plasma under the driving of high-voltage electricity, and is pushed by the rotating gas flow and a gradually-shrinking opening of the reactor to form large-area three-dimensional plasma jet flow, and jet flow gas upwards flows into a coaxial upper-layer catalytic area and downwards flows into a coaxial outer-layer catalytic area due to the limitation of a wall surface; and the reacted gas flows out from a gas guide hole at the lower part. Ammonia gas is firstly activated and pre-decomposed in the arc temperature plasma area and then secondarily decomposed in the coaxial catalytic area, heat of the temperature plasma area directly acts on the catalytic area, and external heating is not needed. The whole structure is that the temperature plasma area and the catalytic area are coaxially integrated, so that the waste heat utilization rate and the reaction energy efficiency are improved. The system is simple and compact in structure, can flexibly supply hydrogen in a distributed manner, is high in energy density, and can be directly driven by wind, light and 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 realizing 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 CO2 concentration 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 potential 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 a problem. 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. For the problem of hydrogen storage and transportation, the emergence of ammonia provides an innovative solution and opens up new ways 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) and requires preheating of the catalyst. In addition, 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. 4 ~10 5 ℃), good chemical selectivity, but its gas processing capacity is small, which cannot meet the needs of large-volume, 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 solve the above-mentioned problems at the same time, realize the rapid and efficient decomposition of ammonia to produce hydrogen, meet the needs 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 prior art and to provide a system and method for the rapid and efficient decomposition of ammonia to produce hydrogen with a compact structure, high energy efficiency and a large gas processing capacity using plasma.

[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 realizing rapid and efficient decomposition of ammonia to produce hydrogen in a plasma-catalyzed and coordinated manner, 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 plate flange, a metal lower cover plate flange, an alumina insulator, a high voltage pole, a rotating deflector, a metal inner electrode, a metal outer electrode and a quartz tube;

[0012] The outside of the metal connection flange is provided with a raw ammonia gas inlet and a low-pressure pole; the upper and lower parts of the metal connection flange are respectively fastened and connected with a metal upper cover plate flange and a metal lower cover plate flange;

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

[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 catalysts;

[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 connection 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 direct current power supply or a frequency-adjustable high-voltage alternating current 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 an adjustable frequency 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 into the arc temperature plasma reactor in real time.

[0021] Furthermore, the ammonia supply device provides gaseous pure ammonia, and the gaseous ammonia 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.

[0022] Furthermore, 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, 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 a fluororubber gasket is used for sealing; 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, the metal inner electrode is coaxially embedded in the circular hole and fixed with screws.

[0024] Furthermore, the exterior 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 arranged on the outer side wall of the rotating flow guide, and ammonia enters from the inlet of the rotating flow guide, and forms a rotating airflow through the action of the tapered port and the rotating flow guide.

[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 tapering mouth of the metal outer electrode, 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 the present specification, a method for realizing rapid and efficient decomposition of ammonia to produce hydrogen by 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 to enter the atmospheric pressure arc warm 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 plasma with high reactivity. The plasma forms a large-area three-dimensional plasma jet under the promotion of the rotating airflow and the tapered mouth of the metal outer electrode. The jet gas flows upward from the outlet of the warm 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, and further reacts with the catalyst to produce hydrogen. The heat generated in the warm 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 holes below the cylindrical alumina inner plate to complete the secondary decomposition of ammonia.

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

[0032] (1) The present invention adopts a coaxial and close 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, 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, so that 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 catalytic reaction efficiency.

[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 facilitates the replacement of metal inner electrodes of different materials and ensures that the metal inner electrode is located in the center of the outer electrode for easy integrated installation.

[0036] (5) Arc temperature plasma catalysis and synergistic enhancement can achieve rapid and efficient decomposition of ammonia to produce hydrogen, and realize distributed flexible hydrogen supply. 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. It can achieve rapid and efficient conversion of large-flux 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 the 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 structural diagram of a system for realizing rapid and efficient decomposition of ammonia to produce hydrogen by plasma catalysis and synergy provided in an embodiment of the present invention;

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

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

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

[0042] Figure 5 A schematic diagram of the structure 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 implementation modes of the present invention are described in detail below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0045] like Figure 1-Figure 5 As shown, an embodiment of the present invention provides a system for realizing rapid and efficient decomposition of 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 adopts a direct current power supply or a frequency-adjustable high-voltage alternating current power supply to supply power to the arc temperature plasma reactor. In specific implementation, when a direct current power supply is adopted, the low-voltage power supply line is connected to the low-voltage pole 17 of the arc temperature plasma reactor, and the high-voltage power supply line is connected to the high-voltage pole 5 of the arc temperature plasma reactor; when a frequency-adjustable high-voltage alternating current power supply is adopted, the low-voltage power supply line is connected to the low-voltage pole 17 of the arc temperature plasma reactor, and the high-voltage power supply line is connected to the high-voltage pole 5 of the arc temperature plasma reactor, and 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.

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

[0048] The ammonia supply device provides gaseous pure ammonia, and the gaseous ammonia 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.

[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 reverse phase catalyst CeO2 / Ni as an example, the reverse 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, and 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 stirring was continued 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 hours, and finally calcined at 400°C for 2 hours to obtain a CeO2 / Ni reverse phase catalyst sample;

[0054] In a specific implementation, before use, reduction was performed at 500° C. with a 30 Vol % H 2 / Ar mixed gas (50 ml / min) 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 guide 8, a tungsten metal inner electrode 9, a metal outer electrode 2, and a quartz tube 6.

[0056] The outer side of the metal connection 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 metal cover plate flanges 19 and metal lower cover plate flanges 15 of the same specifications are respectively provided above and below the metal connection flange 16, and 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 plate flange 1 9, a circular graphite gasket 1 is arranged between the lower surface of the base and the metal connecting flange 16 for ammonia sealing operation; the quartz tube 6 is provided with a heat insulation material 3 polyurethane on the outside, the innermost layer 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, and a disc-shaped alumina porous air guide plate 11 loaded with catalyst is arranged 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 in Figure 5As shown; the cylindrical alumina outer plate 10 with an opening at the bottom has gas guide holes 12 uniformly opened on the walls around the lower part 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 the smallest, 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 openings at the top and bottom.

[0058] Furthermore, if Figure 3 As shown, the high-voltage pole 5 and the alumina insulator 14 are coaxially arranged, and a gap is set between the high-voltage pole 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 set at the center of one end of the high-voltage pole 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 gas inlets 101 are evenly arranged on the outer wall of the rotating deflector 8. Ammonia gas 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, and the metal outer electrode 2 is 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 the diameter of the rotating deflector 8, and they are connected to each other. Ammonia forms a spiral airflow that rotates and rises in the gap between the tungsten metal inner electrode 9 and the metal outer electrode 2. At the same time, driven by high voltage electricity, the spiral airflow drives 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, and 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, and no additional heating is required.

[0062] Furthermore, the quartz tube 6 is wrapped with a heat-insulating material 3 polyurethane 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 coaxial therewith is provided with a cylindrical alumina inner plate 18 with upper and lower openings, and a disc-shaped alumina porous air guide plate 11 is provided above the cylindrical alumina inner plate 18 with upper and lower openings. The cylindrical alumina inner plate 18 with upper and lower openings is sleeved on the outer wall surface of the metal outer electrode 2, so that the wall surfaces are closely attached to each other and a certain gas jet space is left 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 cylindrical alumina inner plate 18 with upper and lower openings to limit its position and prevent it from sliding off.

[0063] In the 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. 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 warm plasma zone 7 of the reactor into the coaxial upper catalytic zone 20. Due to the limitation of the wall boundary, the gas then flows downward into the coaxial outer catalytic zone 4 in a turbulent flow state, and further reacts with the catalyst to produce hydrogen. The reacted gas flows out from the air guide hole 12 below the cylindrical alumina inner plate with an opening at the bottom, and then the gas flows upward and flows out from the outlet 102 at the top of the quartz tube 6. In 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, and no additional heating is required.

[0064] The embodiment of the present invention also provides a method for realizing rapid and efficient decomposition of ammonia to produce hydrogen by 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, so that the ammonia gas is introduced into the normal-pressure arc warm plasma reactor along the four-way 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 mouth 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 warm plasma zone of the reactor into the coaxial upper catalytic zone. Due to the limitation of the wall boundary, the gas then flows downward in a turbulent flow state into the coaxial outer catalytic zone, and further reacts with the catalyst to produce hydrogen. The heat generated in the warm plasma zone directly acts on the coaxial upper catalytic zone and the coaxial outer catalytic zone, without the need for additional heating. The reacted gas flows out from the air guide holes below the cylindrical alumina inner plate to complete the secondary decomposition of ammonia.

[0067] The above 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 technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the above disclosed methods and technical contents without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to 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 realizing rapid and efficient decomposition of ammonia to produce hydrogen by plasma catalysis, characterized in that: The system comprises 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 plate flange, a metal lower cover plate flange, an alumina insulator, a high voltage pole, a rotating deflector, a metal inner electrode, a metal outer electrode and a quartz tube; The outside of the metal connection flange is provided with a raw ammonia gas inlet and a low-pressure pole; the upper and lower parts of the metal connection flange are respectively fastened and connected with a metal upper cover plate flange and a metal lower cover plate flange; The quartz tube has an air outlet at the top and a circular base at the bottom, and the base is embedded in the groove of the metal upper cover flange; the outermost layer inside the quartz tube is provided with a cylindrical alumina outer plate with an opening at the bottom, and the innermost layer coaxial with it is provided with a cylindrical alumina inner plate with openings at the top and bottom; a disc-shaped alumina porous air guide plate loaded with catalyst is provided above the alumina inner plate; air guide holes are evenly opened on the wall surface around the lower part of the alumina outer plate; 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 catalysts; 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 connection 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, characterized in that 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 an adjustable frequency 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 into the arc temperature plasma reactor in real time.

3. The system according to claim 1, characterized in that The ammonia supply device provides gaseous pure ammonia, and the gaseous ammonia 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, characterized in that A circular graphite gasket is arranged between the lower surface of the circular base of the quartz tube and the metal connecting flange, and a circular graphite gasket is arranged 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, characterized in that A gap is provided between the high-voltage pole and the inner wall of the alumina insulator, and a fluororubber gasket is used for sealing; 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. The metal inner electrode is coaxially embedded in the circular hole and fixed with screws.

6. The system according to claim 1, characterized in that The exterior of the quartz tube is provided with heat insulating material polyurethane to reduce heat loss.

7. The system according to claim 1, characterized in that The metal inner electrode is made of tungsten metal; the catalyst is a reverse catalyst CeO2 / Ni.

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

9. The system according to claim 1, characterized in that 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 tapering 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 the method 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 to enter the atmospheric pressure arc warm 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 plasma with high reactivity. The plasma forms a large-area three-dimensional plasma jet under the promotion of the rotating airflow and the tapered mouth of the metal outer electrode. The jet gas flows upward from the outlet of the warm 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, and further reacts with the catalyst to produce hydrogen. The heat generated in the warm 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 holes below the cylindrical alumina inner plate to complete the secondary decomposition of ammonia.

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