Efficient ammonia decomposition hydrogen production system based on Joule heating effect

Abstract

The invention discloses an efficient ammonia decomposition hydrogen production system based on the Joule heating effect and belongs to the technical field of clean energy. The system is composed of an ammonia supply module, a Joule thermally driven ammonia decomposition reaction module and a hydrogenation module. Wherein the ammonia supply module consists of a liquid ammonia storage device, a vaporizing chamber and an ammonia gas storage device; the Joule thermally-driven ammonia decomposition reaction module consists of an ammonia gas flow control valve, a reaction tube gas inlet, a reaction tube gas outlet, a Joule heating electrode tip, a direct-current power supply, a temperature sensor, a thermal insulation layer, a reaction tube, a catalyst and a stainless steel alligator clip; the hydrogenation module is composed of a hydrogen purifying and drying device, a hydrogen compressor, a hydrogen cooling unit, a high-pressure hydrogen storage tank, a hydrogen flow control valve and a hydrogenation machine. The whole process can be started and stably output within one second, the conversion rate and the electrothermal conversion efficiency both exceed 90%, low energy consumption, quick response and safe operation are achieved, the system is particularly suitable for hydrogen refueling station construction in a future hydrogen energy network, and green hydrogen energy economy development is promoted.

Description

Technical Field

[0001] The invention belongs to the technical field of clean energy, and in particular relates to a high-efficiency ammonia decomposition hydrogen production system based on Joule thermal effect. Background Art

[0002] As the global demand for clean energy continues to grow, hydrogen has attracted widespread attention as a clean and efficient energy carrier. However, traditional hydrogen production methods such as steam methane reforming and water electrolysis have problems such as low efficiency, high energy consumption and high cost. In recent years, ammonia (NH3) has been regarded as a potential hydrogen storage medium due to its high energy density and easy storage and transportation. Nevertheless, traditional ammonia decomposition reactions usually need to be carried out in a high temperature environment (>400 ℃), which not only increases energy consumption, but also prolongs the reaction startup time, limiting its widespread application.

[0003] In recent years, catalytic reaction technology based on the Joule heat effect has emerged as an efficient reaction technology. The core of this technology is to combine the catalyst with the conductive material so that it can be used as a heating element to build a closed circuit. Under this architecture, the current flows through the heating element, and the Joule heat generated can directly provide heat for the catalytic reaction, allowing the reaction system to quickly reach the required temperature. Compared with traditional thermal catalytic methods, the Joule heat-driven ammonia decomposition technology has significant advantages. It can not only effectively reduce the heat transfer resistance, greatly increase the heat transfer rate, and shorten the start-up time of ammonia decomposition, but also has a simple device structure and good industrial scale-up production potential. It is expected to achieve large-scale industrial application in the future.

[0004] Chinese patent CN 116553994 A discloses a method for preparing olefins, aromatics and hydrogen by catalytic conversion of methane without oxygen, which uses the Joule heat principle to achieve rapid temperature rise and stable reaction conditions; while Chinese patent CN 116514062A shows an application example of natural gas and CO2 dry gas reforming to produce synthesis gas. These studies show that the application of the Joule heat principle in large-scale industrial reactions has good feasibility and superiority. On this basis, the present invention further expands the scope of application of Joule heat, and optimizes the design specifically for hydrogen production by decomposing ammonia to meet the demand for immediate hydrogen production. Summary of the invention

[0005] The purpose of the present invention is to provide an efficient ammonia decomposition hydrogen production system based on the Joule heat effect to solve the problems of slow startup speed, low energy utilization and low ammonia decomposition efficiency of the ammonia decomposition reaction system. The efficient ammonia decomposition hydrogen production system consists of an ammonia supply module, an ammonia decomposition reaction module driven by Joule heat and a hydrogenation module. The Joule heat generated by the precise control of the current directly heats the special catalyst, so that ammonia (NH3) is rapidly decomposed into nitrogen (N2) and hydrogen (H2), and then N2 is removed by efficient purification and finally directed to the application terminal. The whole process can be started and stably output within 1 second, and the conversion rate and electrothermal conversion efficiency are both over 90%, achieving low energy consumption, rapid response and safe operation, which is particularly suitable for the construction of hydrogenation stations in the future hydrogen energy network and promoting the development of the green hydrogen energy economy. That is, the present invention has the characteristics of instant hydrogen production, low energy consumption, rapid response and safety and reliability, and is suitable for distributed and mobile hydrogen energy applications.

[0006] like Figure 1 and Figure 2 As shown, the ammonia supply module consists of a liquid ammonia storage device 1, a vaporization chamber 2 and an ammonia storage device 3; the Joule heat-driven ammonia decomposition reaction module consists of an ammonia flow control valve 4, a reaction tube air inlet 5, a reaction tube air outlet 6, a Joule heating electrode head 7, a DC power supply 8, a temperature sensor 9, an insulation layer 10, a reaction tube 11, a catalyst 12 and a stainless steel alligator clip 13; the hydrogenation module consists of a hydrogen purification and drying device 14, a hydrogen compressor 15, a hydrogen cooling unit 16, a high-pressure hydrogen storage tank 17, a hydrogen flow control valve 18 and a hydrogenator 19.

[0007] The liquid ammonia is first stored in a liquid ammonia storage device 1 and then transported to a vaporization chamber 2 through a pipeline. In the vaporization chamber 2 , the liquid ammonia is heated and converted into ammonia gas, and the converted ammonia gas then enters an ammonia storage device 3 .

[0008] The ammonia storage device 3 is connected to the reaction tube air inlet 5 through the ammonia flow control valve 4. By adjusting the flow control valve 4, the input amount of ammonia can be accurately controlled so that it can enter the reaction tube 11 smoothly; the ammonia entering the reaction tube 11 undergoes a decomposition reaction under the action of the catalyst 12 to generate a mixture of nitrogen (N2) and hydrogen (H2). There are two Joule heating electrode heads 7 and two stainless steel alligator clips 13. The positive and negative electrodes of the DC power supply 8 are respectively applied to the two Joule heating electrode heads 7. The other ends of the two Joule heating electrode heads 7 are respectively connected to the tails of the stainless steel alligator clips 13. The two stainless steel alligator clips 13 firmly clamp the catalyst 12, which not only ensures the fixation of the catalyst, but also forms a complete current loop, so that the catalyst 12 generates heat based on the Joule heat effect, thereby activating the ammonia decomposition reaction. The temperature sensor 9 monitors the temperature in the reaction tube in real time and feeds back the data to the control system of the DC power supply 8 to maintain the optimal reaction temperature. The insulation layer 10 is wrapped around the outside of the reaction tube 11 to reduce heat loss.

[0009] The mixed gas (mainly hydrogen and nitrogen) produced by the ammonia decomposition reaction is discharged through the reaction tube outlet 6 into the hydrogen purification and drying device 14. Impurities (such as incompletely decomposed ammonia and nitrogen) and moisture in the mixed gas are effectively removed to ensure the purity of the hydrogen. The purified hydrogen is then compressed to a high pressure state by the hydrogen compressor 15 to meet the requirements of storage and transportation. The compressed high-pressure hydrogen is cooled by the hydrogen cooling unit 16, and the cooled high-pressure hydrogen is finally safely stored in the high-pressure hydrogen storage tank 17, waiting to adjust the output flow through the hydrogen flow control valve 18 according to actual needs, and directly filled into vehicles or other equipment that needs hydrogen through the hydrogen filling machine 19.

[0010] Furthermore, the liquid ammonia storage device 1 and the ammonia gas storage device 3 are made of high-strength stainless steel to ensure the safety and corrosion resistance of the system, and are equipped with pressure sensors and safety valves to monitor and control the internal gas pressure in real time.

[0011] Furthermore, the electric heating element in the gasification chamber 2 is made of nickel-chromium alloy (such as Ni 80 Cr 20 ) and uses direct current from a dedicated power supply device outside the system as the heating power supply to set the temperature to an appropriate value (40~100 ℃).

[0012] Furthermore, the Joule heating electrode head 7 uses a copper alloy material with high conductivity, which can improve current transmission efficiency and reduce energy loss.

[0013] Furthermore, the DC power supply 8 adopts a high-performance switching power supply (such as Delta Electronics DPFSeries and Mean Well RSP-750-24), with an output voltage range of 0~60V, and has overload protection and voltage stabilization functions to ensure safe and reliable current transmission.

[0014] Furthermore, the temperature sensor 9 adopts infrared temperature measurement technology to achieve real-time temperature monitoring and feedback control.

[0015] Furthermore, the inner diameter of the reaction tube 11 is 25-45 mm, and the outer diameter is 30-50 mm. The outer wall of the reaction tube 11 is covered with a heat-insulating layer 10 composed of multiple layers of heat-insulating materials, such as ceramic fiber and aluminum silicate fiber, to reduce heat loss and maintain the temperature stability of the reaction environment.

[0016] Furthermore, the catalyst 12 in the reaction tube 11 is composed of a base material or a base material and an active component, wherein the base material can be a metal, a metal mixture or a conductive carbon material (such as carbon paper, honeycomb activated carbon, carbon cloth, carbon block and graphite carbon felt, etc.) in the form of foam, mesh, honeycomb, sheet, etc., and the active component includes a combination of one or more precious metal elements and non-precious metals.

[0017] Further, the metal in the base material and the metal in the metal mixture in the catalyst 12 is one or more of iron, cobalt, nickel, copper, aluminum, zinc, titanium, vanadium, chromium, tin, tungsten and alloys and mixtures thereof. The active component in the catalyst 12 is in the form of oxide, carbide, nitride, silicide, metal element or alloy, specifically including one or more of magnesium, aluminum, calcium, barium, titanium, manganese, vanadium, niobium, tungsten, molybdenum, chromium, iron, cobalt, nickel, copper, zinc, tin, gallium, zirconium, lanthanum, cerium, ruthenium, gold, palladium or platinum.

[0018] Furthermore, when the catalyst 12 is composed of a base material and an active component, the doping amount of the active component is 0.1-20 wt.%, wherein the active component can be loaded or doped on the base material by one or more techniques selected from the group consisting of a surface atomization coating method, an impregnation method, an electrochemical deposition method, an alkali precipitation method, a Joule heat in-situ synthesis method, a hydrothermal method, a chemical vapor deposition method (CVD), or a physical vapor deposition method (PVD).

[0019] Furthermore, the surface atomization coating method of the catalyst 12 first takes 0.1 to 10 grams of active components and evenly disperses them in the ethanol solvent of the Nafion solution to form a mixed slurry; then uses a spray gun with a nozzle diameter of 0.1 to 0.8 mm to atomize the mixed slurry, and evenly coats the atomized slurry on the surface of the substrate material; this process can be repeated multiple times to ensure the uniform distribution of the active components on the substrate, thereby obtaining a highly efficient ammonia decomposition catalytic material.

[0020] Further, the Joule heat in-situ synthesis method of the catalyst 12 first prepares an aqueous solution or organic solution containing an active component precursor at room temperature, then uses a surface atomization coating method or an impregnation method to load these precursors onto a substrate material, and then dries them at 60 to 100 degrees Celsius for 10 to 1000 minutes; then, the substrate material loaded with the active component precursor is placed in a quartz tube, and in a protective atmosphere of 10% volume hydrogen and 90% volume argon, Joule heating is achieved by connecting the alligator clips at both ends of the quartz tube to a stabilized power supply; applying a voltage causes the substrate material to self-heat, and continuously heats for 1 millisecond to 10 seconds within a power range of 100 watts to 30 kilowatts, and finally completes the synthesis of the ammonia decomposition catalytic material. The active component precursors used in the Joule heat in-situ synthesis method include, but are not limited to, one or more combinations of nitrates, soluble halides, sulfates, carbonates, phosphates, methoxides, ethoxides, formates, and acetates of the active component.

[0021] Furthermore, the electrochemical deposition method of the catalyst 12 is to prepare an aqueous solution or organic solution containing an active component precursor at room temperature and adjust the pH value to 3-7; then immerse the substrate material as a cathode in the above solution and connect it to a DC voltage-regulated power supply, while using a platinum mesh as an anode, maintaining a distance between the cathode and the anode of 2-6 cm, setting the voltage to 10-60 volts, and performing an electro-deposition operation for 0.5-2 hours in a constant voltage mode; after completion, wash and dry the sample with deionized water to obtain the final ammonia decomposition catalytic material. It is worth noting that the active component precursor used in the electrochemical deposition method also covers one or more combinations of nitrates, soluble halides, sulfates, carbonates, phosphates, methoxides, ethoxides, formates and acetates of the active component.

[0022] Furthermore, the hydrogen purification and drying device 14 is provided with a separation membrane assembly made of polyimide or polytetrafluoroethylene (PTFE) and a 13X molecular sieve adsorption unit, which is intended to remove unreacted ammonia, nitrogen and other impurities and moisture through a variety of technical means to ensure the output of high-purity hydrogen. After the mixed gas (mainly hydrogen, nitrogen and unreacted ammonia) enters the device from the gas outlet 6, it first passes through the separation membrane assembly, which selectively transmits hydrogen and blocks unreacted ammonia and nitrogen, thereby improving the purity of hydrogen; then, the gas enters the 13X molecular sieve adsorption unit, which effectively adsorbs water vapor and other small molecular impurities.

[0023] Furthermore, the hydrogen compressor 15 is a Hydro-Pac HC series compressor with a maximum output pressure of 15-35 MPa, an oil-free lubrication design, and low noise operation, which is suitable for the high-pressure hydrogen compression requirements of the present invention. The specific model can be selected from HC-35 or HC-50, etc. according to the actual application.

[0024] Furthermore, the cooling unit 16 cools down the compressed hydrogen (to 20-25°C) to avoid damage to the hydrogen storage tank material or affecting the quality of the hydrogen due to high temperature. The cooling unit 16 can use a high-pressure hydrogen compressor of the ZKT-CTH35, HLRD-HC35 or GLW-HT35 series.

[0025] Furthermore, the high-pressure hydrogen storage tank 17 is made of high-strength carbon steel or aluminum alloy material, and is internally equipped with a pressure sensor and a safety valve to ensure the safe storage of hydrogen under high pressure.

[0026] The efficient ammonia decomposition hydrogen production system based on Joule heat effect provided by the present invention realizes integrated process management from liquid ammonia storage to final hydrogen filling by optimizing the design and connection mode of each component. The system not only has the characteristics of rapid start-up, efficient conversion, and low energy consumption, but also takes full consideration of safety, providing strong technical support for the development of future hydrogen energy networks.

[0027] (1) Fast start-up capability: Due to the direct electric heating mechanism, the entire system can be completed from startup to stable output within 1 second, showing excellent response speed;

[0028] (2) High conversion rate and low energy consumption: Ammonia decomposition conversion rate exceeds 90% (such as Figure 3 As shown in the figure), while maintaining the same electric-to-heat conversion efficiency above 90%, greatly improving the overall efficiency of the system; compared with traditional heating methods, the Joule heating effect reduces heat transfer losses and reduces operating costs;

[0029] (3) Multifunctional integration: In addition to the ammonia decomposition function, the system also integrates auxiliary units such as gas purification, compression, and cooling to form a complete hydrogen production solution that is easy to integrate into existing infrastructure, especially for the construction of hydrogen refueling stations in the future hydrogen energy network, providing strong technical support;

[0030] In summary, the present invention provides a new technical path for hydrogen production by decomposing ammonia by introducing the Joule heating effect. Compared with traditional methods, the present invention greatly improves reaction efficiency and safety, significantly reduces operating costs, and provides an innovative solution for realizing a green hydrogen economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the specific embodiments of the present invention, the following will briefly introduce the drawings required for use in the specific embodiments. Obviously, the drawings in the following description only show some embodiments of the present invention.

[0032] Figure 1 This is a schematic diagram of the structure of a highly efficient ammonia decomposition hydrogen production system based on Joule thermal effect;

[0033] Figure 2 A schematic diagram of the three-dimensional structure of the ammonia decomposition reaction device driven by Joule heat;

[0034] Figure 3 This is the curve of ammonia conversion rate changing with time in Example 1.

[0035] Figure 1 and Figure 2 The names of the various parts are: liquid ammonia storage device 1, vaporization chamber 2, ammonia storage device 3, ammonia flow control valve 4, reaction tube air inlet 5, reaction tube air outlet 6, Joule heating electrode head 7, DC power supply 8, temperature sensor 9, insulation layer 10, reaction tube 11, catalyst 12, stainless steel alligator clip 13, hydrogen purification and drying device 14, hydrogen compressor 15, hydrogen cooling unit 16, high-pressure hydrogen storage tank 17, hydrogen flow control valve 18 and hydrogenator 19. DETAILED DESCRIPTION

[0036] In order to explain the technical features and advantages of the present invention in detail, the following is an analysis of its implementation methods and details in conjunction with the accompanying drawings and specific examples. These examples are intended to illustrate the technical solution, not to limit its scope. Other implementation plans derived by technicians in the relevant field based on the guidance of this article without creative work are also within the scope of protection of the present invention.

[0037] like Figure 1 As shown, before starting the system, ensure that the liquid ammonia storage device 1 is filled with an appropriate amount of liquid ammonia, the liquid level is maintained between 30% and 80% of the storage tank capacity, the temperature should be maintained between -33°C and -20°C, the pressure should be controlled between 0.5 MPa and 1.5 MPa, and check the sealing and safety of all connecting pipes. Confirm that the pipelines between the liquid ammonia storage device 1, the vaporization chamber 2, and the ammonia storage device 3 are unobstructed. In addition, verify that the pressure sensor and the safety valve function properly to ensure the safety of subsequent operations. When starting the electric heating element in the vaporization chamber 2, use a nickel-chromium alloy (such as Ni 80 Cr 20 ) and uses the direct current provided by the system's external power supply as the heating power supply, setting the temperature to an appropriate value (40-100 °C) so that liquid ammonia can be smoothly and efficiently converted into ammonia. The preheating process takes about 10-15 minutes. When the vaporization chamber 2 is preheated, open the ammonia flow control valve 4 and adjust the input amount of ammonia (0.1-15 mL / min) according to demand. At this time, ammonia enters the reaction tube 11 through the reaction tube air inlet 5, ready for the next step of ammonia decomposition reaction.

[0038] Before starting the ammonia decomposition reaction, first ensure that the DC power supply 8 is in the off state. Then, connect the DC power supply 8 wire to the Joule heating electrode head 7. Use the stainless steel alligator clip 13 to firmly clamp the strip catalyst 12. Next, turn on the DC power supply 8 and gradually increase the current to a predetermined value (0.1~10A) to make the catalyst 12 heat up based on the Joule heating effect. At the same time, the temperature sensor 9 starts to monitor the temperature in the reaction tube 11 in real time. During the entire ammonia decomposition process, the output current of the DC power supply 8 is adjusted by monitoring the data of the temperature sensor 9 to ensure that the reaction temperature remains within the optimal range.

[0039] After the ammonia decomposition reaction is completed, the generated mixed gas is discharged through the reaction tube outlet 6 and immediately enters the hydrogen purification and drying device 14. In this device, the mixed gas passes through the separation membrane assembly and the molecular sieve adsorption unit to obtain high-purity hydrogen. The purified hydrogen is then compressed to a high pressure state (such as 15~35MPa) by the hydrogen compressor 15. Subsequently, the compressed high-pressure hydrogen is cooled by the cooling unit 16. The cooled high-pressure hydrogen is finally safely stored in the high-pressure hydrogen storage tank 17. The hydrogen storage tank is made of high-strength carbon steel or aluminum alloy material, and is equipped with a pressure sensor and a safety valve inside to ensure the safe storage of hydrogen under high pressure. According to actual needs, the output flow is adjusted by the hydrogen flow control valve 18, and is directly filled into vehicles or other equipment that requires hydrogen through the hydrogen filling machine 19.

[0040] Example 1

[0041] The pH of the precursor solution containing Ru and Cu was adjusted using a 1 mol / L sodium carbonate solution to stabilize the pH in the range of 8 to 9. Subsequently, the reaction was carried out in an oil bath at 80 degrees Celsius for 24 hours. After centrifugation and drying steps, an active component containing 0.1 wt.% Ru and 24 wt.% Cu was obtained. Subsequently, the active component was uniformly dispersed in a Nafion ethanol mixed solution at a concentration of 0.1 mg / mL to form a mixed slurry. The mixed slurry was atomized using a 0.4 mm nozzle spray gun, and the atomized slurry was coated on the surface of a 1 cm*3 cm*0.36 mm carbon fiber cloth. The above coating process was repeated several times until the active component achieved an ideal uniform dispersion state on the substrate, thereby successfully preparing an ammonia decomposition catalytic material. In a reactor with a diameter of 50 mm, the prepared ammonia decomposition catalytic material was firmly clamped with the help of an alligator clip. Ammonia gas was continuously introduced into the reactor, and the gas space velocity was set to 480 ml per hour. The product was accurately tested and analyzed by a gas chromatograph (GC) equipped with a thermal conductivity detector (TCD). The tail gas was treated with a sulfuric acid solution with a concentration of 2 mol / L. Under the conditions of using the catalyst of this embodiment, the ammonia conversion rate can reach 92%, the temperature of the reaction tube inlet 5 is 100°C, and the temperature of the reaction tube outlet 6 is 541°C.

[0042] Example 2

[0043] An active component containing 0.1 wt.% Ru and 20 wt.% Ni was deposited on foamed iron (1 cm*3 cm*2 mm) by electrochemical deposition (see Example 1 for the preparation of the active component) to obtain an ammonia decomposition catalytic material. In a reactor with a diameter of 50 mm, the prepared ammonia decomposition catalytic material was firmly clamped with the aid of an alligator clip. Ammonia was continuously introduced into the reactor, and the gas space velocity was set to 480 ml per hour. The reaction product was accurately tested and analyzed by a gas chromatograph (GC) equipped with a thermal conductivity detector (TCD). The tail gas was treated with a sulfuric acid solution with a concentration of 2 mol / L. Under the conditions of using the catalyst of this embodiment, the ammonia conversion rate can reach 91.5%, the temperature of the reaction tube inlet 5 is 100 ° C, and the temperature of the reaction tube outlet 6 is 763 ° C.

[0044] Example 3

[0045] After the Ru and Ce precursors were mixed with activated carbon by vibrating ball milling, they were reduced at high temperature in a hydrogen / argon atmosphere by a Joule heat in-situ synthesis device to obtain an active component containing 1 wt.% Ru and 8 wt.% Ce. Subsequently, the active component was evenly coated on the surface of 1 cm*3 cm*2 mm nickel-chromium foam by atomic layer deposition technology, thereby obtaining an ammonia decomposition catalytic material. In a reactor with a diameter of 50 mm, the prepared ammonia decomposition catalytic material was firmly clamped by an alligator clip. Ammonia was continuously introduced into the reactor, and the gas space velocity was set to 480 ml per hour. The reaction product was accurately tested and analyzed by a gas chromatograph (GC) equipped with a thermal conductivity detector (TCD). The tail gas was treated with a sulfuric acid solution with a concentration of 2 mol / L. Under the conditions of using the catalyst of this embodiment, the ammonia conversion rate can reach 93%, the temperature of the reaction tube inlet 5 is 100 °C, and the temperature of the reaction tube outlet 6 is 623 °C.

[0046] The above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes can be made based on the above description, and all implementation methods are not exhaustively listed here. However, obvious changes derived therefrom are still within the scope of protection of the present invention.

Claims

1. An efficient ammonia decomposition hydrogen production system based on Joule thermal effect, characterized by: The system comprises an ammonia supply module, a Joule heat-driven ammonia decomposition reaction module and a hydrogenation module; wherein the ammonia supply module comprises a liquid ammonia storage device (1), a vaporization chamber (2) and an ammonia storage device (3); the Joule heat-driven ammonia decomposition reaction module comprises an ammonia flow control valve (4), a reaction tube air inlet (5), a reaction tube air outlet (6), a Joule heating electrode head (7), a DC power supply (8), a temperature sensor (9), an insulation layer (10), a reaction tube (11), a catalyst (12) and a stainless steel alligator clip (13); the hydrogenation module comprises a hydrogen purification and drying device (14), a hydrogen compressor (15), a hydrogen The invention comprises a cooling unit (16), a high-pressure hydrogen storage tank (17), a hydrogen flow control valve (18) and a hydrogenator (19); liquid ammonia is first stored in a liquid ammonia storage device (1), and then transmitted to a vaporization chamber (2) through a pipeline; the liquid ammonia is heated in the vaporization chamber (2) and converted into ammonia gas, and the converted ammonia gas then enters an ammonia storage device (3); the ammonia storage device (3) is connected to an air inlet (5) of a reaction tube through an ammonia flow control valve (4); the ammonia gas entering the reaction tube (11) undergoes a decomposition reaction under the action of a catalyst (12) to generate a mixed gas of nitrogen (N2) and hydrogen (H2); the Joule heating electrode head (7) and There are two stainless steel alligator clips (13), the positive and negative electrodes of the DC power supply (8) are applied to the two Joule heating electrode heads (7) respectively, and the other ends of the two Joule heating electrode heads (7) are connected to the tails of the stainless steel alligator clips (13) respectively. The two stainless steel alligator clips (13) firmly clamp the catalyst (12) to ensure the fixation of the catalyst and form a complete current loop, so that the catalyst (12) generates heat based on the Joule thermal effect, thereby activating the ammonia decomposition reaction; the temperature sensor (9) monitors the temperature in the reaction tube (11) in real time, and feeds back the data to the control system of the DC power supply (8) to maintain the optimal reaction temperature; the insulation layer (10) is wrapped around the outside of the reaction tube (11) to reduce heat loss; the mixed gas generated by the ammonia decomposition reaction is discharged through the reaction tube outlet (6) into the hydrogen purification and drying device (14), and impurities and moisture in the mixed gas are effectively removed; the purified hydrogen is then compressed to a high pressure state by the hydrogen compressor (15), and the compressed high-pressure hydrogen is cooled by the hydrogen cooling unit (16). The cooled high-pressure hydrogen is finally stored in the high-pressure hydrogen storage tank (17), and the output flow is adjusted by the hydrogen flow control valve (18), and is directly filled into vehicles or other equipment requiring hydrogen through the hydrogen filling machine (19).

2. The efficient ammonia decomposition hydrogen production system based on Joule thermal effect as claimed in claim 1, characterized in that: The liquid ammonia storage device (1) and the ammonia gas storage device (3) are made of high-strength stainless steel and are equipped with a pressure sensor and a safety valve.

3. The efficient ammonia decomposition hydrogen production system based on Joule thermal effect as claimed in claim 1, characterized in that: The electric heating element in the vaporization chamber (2) adopts a high-efficiency resistance heating wire made of nickel-chromium alloy, and uses direct current provided by a dedicated power supply device outside the system as a heating power supply, and sets the temperature to 40~100°C.

4. The efficient ammonia decomposition hydrogen production system based on Joule thermal effect as claimed in claim 1, characterized in that: The Joule heating electrode head (7) is made of a copper alloy material with high conductivity; the DC power supply (8) is a high-performance switching power supply with an output voltage range of 0 to 60 V and has overload protection and voltage stabilization functions; the temperature sensor (9) uses infrared temperature measurement technology.

5. The efficient ammonia decomposition hydrogen production system based on Joule thermal effect as claimed in claim 1, characterized in that: The inner diameter of the reaction tube (11) is 25-45 mm, and the outer diameter is 30-50 mm; the material of the thermal insulation layer (10) is ceramic fiber or aluminum silicate fiber.

6. The efficient ammonia decomposition hydrogen production system based on Joule thermal effect as claimed in claim 1, characterized in that: The catalyst (12) is composed of a base material or a base material and an active component. The base material is a metal, a metal mixture or a conductive carbon material in the form of foam, mesh, honeycomb, sheet or the like. The conductive carbon material is one of carbon paper, honeycomb activated carbon, carbon cloth, carbon block and graphite carbon felt. The metal in the metal or metal mixture is one or more of iron, cobalt, nickel, copper, aluminum, zinc, titanium, vanadium, chromium, tin, tungsten and their alloys or mixtures. The active component is a combination of one or more precious metal elements and non-precious metals. The active component exists in the form of oxide, carbide, nitride, silicide, metal element or alloy. The metal in the active component is one or more of magnesium, aluminum, calcium, barium, titanium, manganese, vanadium, niobium, tungsten, molybdenum, chromium, iron, cobalt, nickel, copper, zinc, tin, gallium, zirconium, lanthanum, cerium, ruthenium, gold, palladium or platinum.

7. The efficient ammonia decomposition hydrogen production system based on Joule thermal effect as claimed in claim 6, characterized in that: When the catalyst (12) is composed of a substrate material and an active component, the doping amount of the active component is 0.1 to 20 wt.%; the active component is loaded or doped on the substrate material by one or more techniques selected from the group consisting of surface atomization coating, impregnation, electrochemical deposition, alkali precipitation, Joule heat in-situ synthesis, hydrothermal, chemical vapor deposition (CVD) or physical vapor deposition (PVD).

8. The efficient ammonia decomposition hydrogen production system based on Joule thermal effect as claimed in claim 1, characterized in that: The hydrogen purification and drying device (14) is provided with a separation membrane component made of polyimide or polytetrafluoroethylene (PTFE) and a 13X molecular sieve adsorption unit.

9. The efficient ammonia decomposition hydrogen production system based on Joule thermal effect as claimed in claim 1, characterized in that: The output pressure of the hydrogen compressor (15) is 15-35 MPa; the cooling unit (16) cools the compressed hydrogen to 20-25°C.

10. The efficient ammonia decomposition hydrogen production system based on Joule thermal effect as claimed in claim 1, characterized in that: The high-pressure hydrogen storage tank (17) is made of high-strength carbon steel or aluminum alloy material, and is internally equipped with a pressure sensor and a safety valve.

Images