A high pressure ammonia cracking system and method of a plasma coupled catalyst

Abstract

The application discloses a high-pressure ammonia cracking system and method of a plasma coupling catalyst, and the system comprises a control unit, an ammonia fuel supply system, a driving power supply, a cracker, a heat exchange module, a cooling and separating chamber and an ammonia hydrogen supply end; the ammonia fuel supply system is connected with the cracker, liquid ammonia is sent into a cooling jacket of the cracker, and then preheated by the heat exchange module; the preheated ammonia gas is sent into the cracker to be subjected to plasma cracking and thermal cracking; the high-temperature hydrogen, nitrogen and ammonia mixed gas after the cracking is sent into the heat exchange module to provide heat for the preheated liquid ammonia; then the mixed gas is subjected to cooling and hydrogen separation and purification in the cooling and separating chamber; the prepared hydrogen is sent into the ammonia hydrogen supply end; and the control unit is connected with the ammonia fuel supply system, the driving power supply, the heat exchange module and the cooling and separating chamber and is used for regulation and control. The application greatly improves the cracking efficiency of ammonia; more power is not needed, so that the dependence of the whole device on electricity is reduced; and the whole device is allowed to operate at a higher working gas pressure.

Description

Technical Field

[0001] This invention belongs to the field of plasma and ammonia applications, specifically relating to a high-pressure ammonia cracking system and method using plasma-coupled catalysts. Background Technology

[0002] Currently, low-carbon fuels mainly include ethanol, biodiesel, dimethyl ether and hydrogen. Among them, hydrogen energy is favored as an efficient and clean energy carrier. However, due to its own physical and chemical properties, hydrogen also faces a series of problems in storage, transportation and safety: (1) Hydrogen is very difficult to liquefy, resulting in high costs for liquefaction, storage and transportation; (2) Hydrogen has a very wide flammability range and a very high flame propagation speed, making it prone to explosion during storage and transportation; (3) Hydrogen is colorless and odorless, and leaks are not easily detected; (4) Hydrogen emits very weak radiation when burning, making it difficult to detect and monitor.

[0003] Ammonia is a high-quality hydrogen storage carrier with a theoretical hydrogen storage capacity of up to 17.6 wt%. It has the following advantages: (1) Ammonia is easy to liquefy, and the liquefaction, storage and transportation costs are low; (2) Ammonia has a high octane number, a slow flame propagation speed and a narrow flammable range, making storage and transportation relatively safe; (3) Ammonia has an irritating odor, and a leak can be detected when the concentration reaches 5 ppm; (4) Ammonia emits strong radiation when it burns, making it easy to detect and monitor.

[0004] However, due to the low flame propagation speed, high ignition energy, and unstable combustion of ammonia, NO... X Excessive emissions and traditional emission reduction methods for ammonia fuel are mostly post-treatment technologies, lacking new methods and systems that reduce emissions from the combustion perspective. Ammonia has not yet been used directly as fuel in industrial applications. Therefore, ammonia cracking has received widespread attention as an effective on-site hydrogen production method.

[0005] Thermal cracking of ammonia is currently the main method for directly producing high-purity hydrogen. However, thermal cracking equipment is bulky, the efficiency of ammonia cracking largely depends on the performance of the catalyst, and it suffers from high energy consumption, short reactor life, and operating at atmospheric pressure, making it unsuitable for high-pressure applications. Plasma technology can provide high chemical activity and energy efficiency for chemical reactions, enabling reactions that are difficult to occur under conventional conditions to proceed at lower temperatures. It offers advantages such as high efficiency and low energy consumption. However, current plasma technology is mostly applied under low or atmospheric pressure conditions, and high-power discharge plasma also faces problems such as low electrode life and low discharge stability. Summary of the Invention

[0006] The objective and technical problem of this invention is to address the significant challenges facing the development of traditional internal combustion locomotives in the context of environmental and energy crises, and to solve the problems of low flame propagation speed, high ignition energy, and unstable combustion associated with the direct combustion of ammonia as fuel. This invention provides a high-pressure ammonia cracking system using plasma and a catalyst. This system fully leverages the advantages of plasma technology and utilizes ammonia discharge plasma to provide heat for ammonia thermal cracking, thereby improving its applicability, flexibility, and stability in more application scenarios, reducing the dependence of the ammonia cracking process on electricity for hydrogen production, and thus increasing the rational application pathways of ammonia fuel.

[0007] To achieve the above objectives, the technical solution adopted in this invention is as follows: a high-pressure ammonia cracking system using plasma and catalyst, comprising a control unit, an ammonia fuel supply system, a driving power supply, a cracker, a heat exchange module, a cooling separation chamber, and an ammonia-hydrogen supply end. The ammonia fuel supply system is connected to the cracker, and liquid ammonia is fed into the cracker's cooling jacket and preheated by the heat exchange module. The preheated ammonia is then fed into the cracker for plasma cracking and thermal cracking. The resulting high-temperature hydrogen, nitrogen, and ammonia mixture is fed into the heat exchange module to provide heat for the preheated liquid ammonia. Subsequently, the mixture is cooled and purified by hydrogen separation in the cooling separation chamber, and the prepared hydrogen is fed into the ammonia-hydrogen supply end. The control unit is connected to and regulates the ammonia fuel supply system, the driving power supply, the heat exchange module, and the cooling separation chamber to achieve stable operation of the cracking system.

[0008] Specifically, a high-pressure ammonia cracking system with a plasma-coupled catalyst includes:

[0009] An ammonia fuel supply system, comprising a liquid ammonia storage tank and a liquid ammonia pump;

[0010] A driving power supply, which is used to break down ammonia gas to generate plasma and control plasma parameters;

[0011] The pyrolyzer is used to generate plasma to pyrolyze ammonia and use the discharge plasma to supply heat to the catalyst. Under the action of the catalyst, the unpyrolyzed ammonia is thermally pyrolyzed. The pyrolyzer includes a cooling sleeve, a pyrolysis tube, an insulation sleeve, a tube seat, an anode column, an anode, a cathode, a partition plate, a catalyst bed, a catalyst, a cooling inlet, a cooling outlet, an air inlet, and an air outlet.

[0012] The heat exchange module collects the heat from the mixture of ammonia, hydrogen, and nitrogen after cracking, thereby achieving comprehensive energy utilization, improving overall thermal efficiency, and solving the problem of low-temperature vaporization of liquid ammonia.

[0013] The cooling separation chamber has a pressure higher than the ammonia liquefaction pressure, which causes the ammonia to liquefy and form a separation liquid. The ammonia is then separated from hydrogen and nitrogen. The gas formed after separation is sent to the ammonia-hydrogen supply end for use by the application end.

[0014] Ammonia-hydrogen supply end, wherein the supply end provides hydrogen, nitrogen, or a mixture of nitrogen and hydrogen;

[0015] The control unit regulates the ammonia fuel supply system, drive power supply, and heat exchange module to perform parameterized automatic control of the pyrolysis system.

[0016] Furthermore, the ammonia fuel supply system is sealed to the pyrolyzer via a stainless steel or carbon steel metal pipe. Liquid ammonia is pumped out from the liquid ammonia storage tank by a liquid ammonia pump, and the liquid ammonia injection pressure is regulated. The liquid ammonia is then sent into the pyrolyzer through the metal pipe.

[0017] Furthermore, the driving power supply is a high-frequency AC power supply, and its working mode is either continuous wave mode or pulse mode. In pulse mode, the pulse frequency is 1Hz-100kHz and the duty cycle is 1%-99%. The hydrogen-ammonia ratio of the hydrogen-ammonia mixture after ammonia cracking can be adjusted by adjusting the power of the plasma generator. The driving power supply is connected to the anode column through a high-voltage transmission line.

[0018] Furthermore, the shell of the pyrolyzer is a pyrolyzer tube, and the partition plate is welded inside the pyrolyzer tube to divide it into a plasma pyrolyzer region and a thermal pyrolyzer region. The partition plate has holes for the pyrolyzer gas to be fed from the plasma region into the thermal pyrolyzer region. The cathode is finned and uniformly welded and fixed to the inner wall of the pyrolyzer tube. The tube seat is installed at one end of the pyrolyzer tube, and it has a groove at the center of the partition plate for placing the anode column. The anode is finned and uniformly welded to the anode column. The anode column is rotatable, and the distance between the anode fins and the cathode fins changes during rotation. The driving power supply is connected to the anode column via a high-voltage transmission line through the tube seat. The pressure inside the pyrolyzer tube can be 0.1–10 MPa, and the temperature can be 600–1200℃. The thermal pyrolyzer region of the pyrolyzer tube... A catalyst bed is placed on the catalyst, and the temperature inside the catalyst bed can reach 500-600℃. The catalyst is 10-30%wt nickel-alumina, 10-30%wt cobalt-alumina, 10-30%wt ruthenium-alumina, iron catalyst, manganese catalyst, palladium catalyst, lanthanum catalyst, molybdenum catalyst, or any combination thereof. A cooling sleeve is installed outside the plasma region of the pyrolysis tube. The cooling sleeve has a spiral pipe inside and a cooling inlet and a cooling outlet at both ends. The cooling outlet is connected to an ammonia fuel supply system. Liquid ammonia flows into the cooling sleeve through the cooling inlet to cool the pyrolysis tube in the plasma region and flows out through the cooling outlet. An insulation sleeve is installed outside the thermal pyrolysis region of the pyrolysis tube to prevent heat loss. One end of the insulation sleeve has a gas outlet.

[0019] Furthermore, the heat exchange module has two input terminals and two output terminals, and fins are added to the internal pipes to increase the heat exchange area; the cooling outlet on the cooling sleeve is connected to the first input terminal of the heat exchange module, the first output terminal of the heat exchange module is connected to the air inlet of the pyrolyzer, the air outlet of the pyrolyzer is connected to the second input terminal of the heat exchange module, and the second output terminal of the heat exchange module is connected to the input terminal of the cooling separation chamber; the high-temperature mixed gas of ammonia / hydrogen / nitrogen after pyrolysis is sent into the heat exchange module through the air outlet to recover waste heat, and the liquid ammonia flowing out from the cooling outlet is sent into the heat exchange module for preheating and then injected into the pyrolyzer through the air inlet by the ammonia injector for plasma pyrolysis to produce hydrogen.

[0020] Furthermore, the cooling separation chamber has one input end and two output ends. The second output end of the heat exchange module is connected to the input end of the cooling separation chamber, the first output end is connected to the supply end, and the second output end is connected to the first input end of the heat exchange module. When the cooling separation chamber does not cool or pressurize, the composition of the cracked mixed gas remains unchanged and is fed into the ammonia-hydrogen supply end. Alternatively, the ammonia in the cracked mixed gas is liquefied by cooling to the ammonia liquefaction temperature (-33°C), or by cooling and pressurizing (e.g., room temperature 1–2 MPa) to the ammonia liquefaction conditions; or by cooling to the nitrogen liquefaction temperature (-196°C) to liquefy both nitrogen and ammonia, and hydrogen is separated and fed into the ammonia-hydrogen supply end. At this time, the atmosphere that the ammonia-hydrogen supply end can provide can be a mixture of hydrogen, nitrogen, and hydrogen, or a mixture of ammonia, hydrogen, and nitrogen. The separated ammonia or liquid ammonia is fed into the first input end of the heat exchange module through the second output end of the cooling separation chamber.

[0021] Furthermore, the ammonia-hydrogen supply end is located after the first output end of the cooling separation chamber; after the cracked mixed gas passes through the cooling separation chamber, the gas temperature drops to room temperature or below the critical temperature, while the pressure of the cooling separation chamber is kept higher than the ammonia liquefaction pressure so that the ammonia is liquefied to form a separated liquid ammonia, which is then separated from hydrogen and nitrogen. The gas formed after separation is sent to the ammonia-hydrogen supply end for use by the application end.

[0022] Furthermore, the control unit is connected to the ammonia fuel supply system, the drive power supply, the heat exchange module, and the cooling separation chamber, respectively, to regulate the output flow rate of liquid ammonia, the output power of the drive power supply, the thermal balance of the heat exchange module, and the temperature and pressure control of the cooling separation chamber, so as to achieve stable operation of the pyrolysis system and obtain the best pyrolysis performance.

[0023] This invention also provides a high-pressure ammonia cracking method using a plasma-coupled catalyst. The ammonia fuel supply system and the cracker are sealed together via a stainless steel or carbon steel metal pipe using any of the plasma-coupled catalyst high-pressure cracking systems described above. Liquid ammonia is pumped from a liquid ammonia storage tank via a liquid ammonia pump, and the liquid ammonia injection pressure is regulated. The liquid ammonia is then fed into the cracker via the metal pipe. The driving power supply is a high-frequency AC power supply, operating in either continuous wave or pulse mode. In pulse mode, the pulse frequency is 1Hz-100kHz, and the duty cycle is 1%-99%. The hydrogen-ammonia ratio of the hydrogen-ammonia mixture after ammonia cracking can be adjusted by adjusting the power of the plasma generator. The driving power supply is connected to the anode column via a high-voltage transmission line. The pyrolyzer is connected to a plasma pyrolysis tube. A partition plate is welded inside the pyrolysis tube, dividing it into a plasma pyrolysis zone and a thermal pyrolysis zone. The partition plate has holes for feeding pyrolysis gas from the plasma zone into the thermal pyrolysis zone. The cathode is finned and uniformly welded to the inner wall of the pyrolysis tube. A tube seat is installed at one end of the pyrolysis tube, and a groove is provided at the center of the partition plate for placing the anode column. The anode is finned and uniformly welded to the anode column. The anode column is rotatable, and the distance between the anode and cathode fins changes during rotation. The driving power supply is connected to the anode column via a high-voltage transmission line through the tube seat. The pressure inside the pyrolysis tube can be 0.1-10 MPa, and the temperature can be 600–100 °C. 200℃; a catalyst bed is placed in the thermal pyrolysis zone of the pyrolysis tube, and the catalyst is placed on the catalyst bed, the internal temperature of which can reach 500-600℃; the catalyst is 10-30%wt nickel-alumina, 10-30%wt cobalt-alumina, 10-30%wt ruthenium-alumina, iron catalyst, manganese catalyst, palladium catalyst, lanthanum catalyst, molybdenum catalyst, or any combination thereof; a cooling jacket is installed outside the plasma zone of the pyrolysis tube, and a spiral pipe is provided inside the cooling jacket. The cooling jacket has a cooling inlet and a cooling outlet at both ends. The cooling outlet is connected to the ammonia fuel supply system. Liquid ammonia flows into the cooling jacket through the cooling inlet to cool the pyrolysis tube in the plasma zone, and flows out through the cooling outlet; the pyrolysis tube An insulating sleeve is installed outside the pyrolysis zone to prevent heat loss. One end of the insulating sleeve has an outlet. The heat exchange module has two input ends and two output ends, and fins are added to the internal pipes to increase the heat exchange area. The cooling outlet on the cooling sleeve is connected to the first input end of the heat exchange module, the first output end of the heat exchange module is connected to the inlet of the pyrolyzer, the outlet of the pyrolyzer is connected to the second input end of the heat exchange module, and the second output end of the heat exchange module is connected to the input end of the cooling separation chamber. The high-temperature mixed gas of ammonia / hydrogen / nitrogen after pyrolysis is sent to the heat exchange module through the outlet to recover waste heat. The liquid ammonia flowing out from the cooling outlet is sent to the heat exchange module for preheating and then injected into the pyrolyzer through the inlet by the ammonia injector for plasma pyrolysis to produce hydrogen.The cooling separation chamber has one input end and two output ends. The second output end of the heat exchange module is connected to the input end of the cooling separation chamber, the first output end is connected to the supply end, and the second output end is connected to the first input end of the heat exchange module. When the cooling separation chamber does not cool or pressurize, the composition of the cracked gas mixture remains unchanged and is fed into the ammonia-hydrogen supply end. Alternatively, the ammonia in the cracked gas mixture is liquefied by cooling to the ammonia liquefaction temperature (-33℃), or by cooling and pressurizing (e.g., room temperature 1-2 MPa) to the ammonia liquefaction conditions; or by cooling to the nitrogen liquefaction temperature (-196℃) to simultaneously liquefy nitrogen and ammonia, separating hydrogen and feeding it into the ammonia-hydrogen supply end. At this time, the atmosphere that the ammonia-hydrogen supply end can provide can be a mixture of hydrogen, nitrogen, and hydrogen, or a mixture of ammonia, hydrogen, and nitrogen. The separated ammonia gas or liquid ammonia is fed into the first input terminal of the heat exchange module through the second output terminal of the cooling separation chamber; the ammonia-hydrogen supply terminal is located after the first output terminal of the cooling separation chamber; after the cracked mixed gas passes through the cooling separation chamber, the gas temperature drops to room temperature or below the critical temperature, while the pressure of the cooling separation chamber is maintained higher than the ammonia liquefaction pressure to liquefy the ammonia and separate it from the hydrogen and nitrogen. The gas formed after separation is sent to the ammonia-hydrogen supply terminal for use by the application end; the control unit is connected to the ammonia fuel supply system, the drive power supply, the heat exchange module, and the cooling separation chamber respectively, and regulates the output flow rate of liquid ammonia, the output power of the drive power supply, the thermal balance of the heat exchange module, and the temperature and pressure control of the cooling separation chamber to achieve stable operation of the cracking system and thus obtain optimal cracking performance.

[0024] The advantages of this invention are:

[0025] 1. This invention combines plasma pyrolysis with catalytic thermal pyrolysis for hydrogen production, which greatly improves the pyrolysis efficiency of ammonia.

[0026] 2. This invention improves the shape of the anode and cathode by setting a finned electrode array. The anode is rotated by the ammonia gas flow to change the electrode spacing, forming a rotating sliding arc, which increases the plasma volume and improves the efficiency of plasma cracking of ammonia.

[0027] 3. The system involved in this invention is a high-pressure ammonia cracking system with plasma-coupled catalyst. It provides the heat required for thermal cracking through discharge plasma, without requiring more electricity, thus reducing the overall dependence of the device on electricity.

[0028] 4. This invention allows the entire device to operate at a higher working pressure, further reducing the size and weight of the entire device and increasing the compactness, lightweight nature, flexibility, and adaptability of the ammonia cracker to various application scenarios. Attached Figure Description

[0029] Figure 1This is a schematic diagram of a high-pressure ammonia cracking system based on a plasma-coupled catalyst according to the present invention.

[0030] In the diagram, 1-control unit, 2-ammonia fuel supply system, 3-drive power supply, 4-cracker, 401-cooling sleeve, 402-cracking tube, 403-insulation sleeve, 404-tube seat, 405-anode column, 406-anode, 407-cathode, 408-partition plate, 409-catalyst bed, 410-catalyst, 411-cooling inlet, 412-cooling outlet, 413-air inlet, 414-air outlet, 5-heat exchange module, 6-cooling separation chamber, 7-ammonia-hydrogen supply end. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0032] The specific application and implementation methods of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0033] like Figure 1 As shown, a high-pressure ammonia cracking system with plasma-coupled catalyst includes a control unit 1, an ammonia fuel supply system 2, a drive power supply 3, a cracker 4, a heat exchange module 5, a cooling separation chamber 6, and an ammonia-hydrogen supply end 7.

[0034] The pyrolyzer 4 includes a cooling jacket 401, a pyrolysis tube 402, an insulation jacket 403, a tube seat 404, an anode column 405, an anode 406, a cathode 407, a partition plate 408, a catalyst bed 409, a catalyst 410, a cooling inlet 411, a cooling outlet 412, an air inlet 413, and an air outlet 414. The ammonia fuel supply system includes a liquid ammonia storage tank and a liquid ammonia pump. A driving power supply is provided to break down ammonia gas to generate plasma and control plasma parameters.

[0035] The ammonia fuel supply system 2 and the pyrolyzer 4 are sealed together by a stainless steel or carbon steel metal pipe. Liquid ammonia is pumped out from the liquid ammonia storage tank by a liquid ammonia pump to regulate the liquid ammonia injection pressure. The liquid ammonia is then sent into the pyrolyzer 4 through the metal pipe.

[0036] The shell of the pyrolyzer 4 is a pyrolyzer tube 402. The cathode 407 is finned and uniformly welded and fixed to the inner wall of the pyrolyzer tube 402. The tube seat 404 is installed at one end of the pyrolyzer tube 402. The center of the tube seat 404 and the center of the partition plate 408 are respectively provided with hemispherical grooves. The anode 406 is finned and uniformly welded to the anode column 405. The two ends of the anode column 405 are hemispherical and installed in the hemispherical grooves at the center of the tube seat 404 and the partition plate 408. The partition plate 408 is welded inside the pyrolyzer tube 402 to divide the pyrolyzer tube 402 into a plasma pyrolyzer region and a thermal pyrolyzer region. The partition plate 408 is provided with holes for the pyrolyzer gas to be sent from the plasma region to the thermal pyrolyzer region. A catalyst bed 409 is placed within the pyrolysis zone of the pyrolysis tube 402, and the catalyst 410 is placed on the catalyst bed 409. A cooling sleeve 401 is installed outside the plasma zone of the pyrolysis tube 402. A spiral pipe is provided inside the cooling sleeve 401. Cooling inlets 411 and cooling outlets 412 are provided at both ends of the cooling sleeve 401. The cooling outlet 412 is connected to the ammonia fuel supply system 2. Liquid ammonia flows into the cooling sleeve 401 through the cooling inlet 411 to cool the pyrolysis tube 402 in the plasma zone and flows out through the cooling outlet 412. An insulation sleeve 403 is installed outside the pyrolysis zone of the pyrolysis tube 402 to prevent heat loss. One end of the insulation sleeve 403 is provided with an outlet 414.

[0037] The heat exchange module 5 has two input terminals and two output terminals, and fins are added to the internal pipes to increase the heat exchange area. The cooling outlet 412 on the cooling sleeve 401 is connected to the first input terminal of the heat exchange module 5, the first output terminal of the heat exchange module 5 is connected to the air inlet 413 of the pyrolyzer 4, the air outlet 414 of the pyrolyzer 4 is connected to the second input terminal of the heat exchange module 5, and the second output terminal of the heat exchange module 5 is connected to the input terminal of the cooling separation chamber 6. Liquid ammonia flowing out from the cooling outlet 412 is sent to the heat exchange module 5 for preheating and then injected into the pyrolyzer 4 through the air inlet 413 by an ammonia injector. The injected airflow drives the anode 406 to rotate, and the distance between the anode 406 and the cathode 407 fins changes during rotation. The driving power supply 3 is connected to the anode column 405 through a high-voltage transmission line. The driving power supply 3 is a high-frequency AC power supply, and its working mode is continuous wave mode or It is in pulse mode, with a pulse frequency of 1Hz-100kHz and a duty cycle of 1%-99%. When the power is turned on, the point where the electrode spacing between the anode 406 and the cathode 407 is minimized is broken down, generating an electric arc. Driven by ammonia gas, the anode begins to rotate, and the electric arc continues to rotate and lengthen, generating a large volume of high-temperature plasma in the cracking tube 402. The pressure inside the cracking tube 402 can be 0.1-10MPa, and the temperature can reach 600-1200℃. Ammonia gas is finally cracked into H2 and N2 through a dehydrogenation reaction. The high-temperature cracked gas is sent into the thermal cracking zone through holes in the partition plate 408 and heats the catalyst 410 for thermal cracking, further improving the ammonia cracking rate. The temperature of the catalyst 410 can reach 500-600℃. The hydrogen-ammonia ratio of the hydrogen-ammonia mixture after ammonia cracking can be adjusted by adjusting the power of the plasma generator.

[0038] The high-temperature mixture of ammonia / hydrogen / nitrogen after cracking is sent to the heat exchange module 5 through outlet 414 to recover waste heat, and then sent to the cooling separation chamber 6. The cooling separation chamber 6 has one input end and two output ends. The second output end of the heat exchange module 5 is connected to the input end of the cooling separation chamber 6, the first output end of the cooling separation chamber 6 is connected to the ammonia-hydrogen supply end 7, and the second output end of the cooling separation chamber 6 is connected to the first input end of the heat exchange module 5. When the cooling separation chamber 6 does not cool or pressurize, the composition of the cracked mixture remains unchanged and is sent to the ammonia-hydrogen supply end 7, or... The ammonia in the cracked mixture is liquefied by cooling to the ammonia liquefaction temperature (-33°C), or by cooling and pressurizing (e.g., room temperature, 1-2 MPa) to the ammonia liquefaction conditions; or by cooling to the nitrogen liquefaction temperature (-196°C) to liquefy both nitrogen and ammonia, and hydrogen is separated and sent to the ammonia-hydrogen supply end 7; at this time, the atmosphere that the ammonia-hydrogen supply end 7 can provide can be a mixture of hydrogen, nitrogen and hydrogen, or a mixture of ammonia, hydrogen and nitrogen; the separated ammonia or liquid ammonia is sent to the first input end of the heat exchange module 5 through the second output end of the cooling separation chamber 6.

[0039] The ammonia-hydrogen supply end 7 is located after the first output end of the cooling separation chamber 6. After the cracked mixed gas passes through the cooling separation chamber 6, the gas temperature drops to room temperature or below the critical temperature. At the same time, the pressure of the cooling separation chamber 6 is maintained higher than the ammonia liquefaction pressure to liquefy the ammonia and separate it from the hydrogen and nitrogen. The gas formed after separation is sent to the ammonia-hydrogen supply end 7 for use by the application end. The control unit 1 is connected to the ammonia fuel supply system 2, the drive power supply 3, the heat exchange module 5 and the cooling separation chamber 6 respectively. It regulates the output flow rate of liquid ammonia, the output power of the drive power supply 3, the heat balance of the heat exchange module 5 and the temperature and pressure control of the cooling separation chamber 6 to achieve stable operation of the cracking system and obtain the best cracking performance.

[0040] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-pressure ammonia cracking system with a plasma-coupled catalyst, characterized in that: include: An ammonia fuel supply system, comprising a liquid ammonia storage tank and a liquid ammonia pump; A driving power supply, which is used to break down ammonia gas to generate plasma and control plasma parameters; The pyrolyzer is used to generate plasma to pyrolyze ammonia and to use the discharge plasma to supply heat to the catalyst. Under the action of the catalyst, the unpyrolyzed ammonia is thermally pyrolyzed. The pyrolyzer includes a cooling sleeve, a pyrolysis tube, an insulation sleeve, a tube seat, an anode column, an anode, a cathode, a partition plate, a catalyst bed, a catalyst, a cooling inlet, a cooling outlet, an air inlet, and an air outlet. A heat exchange module that collects the heat from the cracked mixture of ammonia, hydrogen, and nitrogen. Cooling separation chamber; ammonia-hydrogen supply side; The driving power supply is connected to the anode column via a high-voltage transmission line; the shell of the pyrolyzer is a pyrolyzer tube, and the partition plate is welded inside the pyrolyzer tube to divide it into a plasma pyrolyzer region and a thermal pyrolyzer region. The partition plate has holes for the pyrolyzer gas to be fed from the plasma region into the thermal pyrolyzer region; the cathode is finned and uniformly welded to the inner wall of the pyrolyzer tube; the tube seat is installed at one end of the pyrolyzer tube, and it has a groove at the center of the partition plate for placing the anode column. The anode is finned and uniformly welded to the anode column; the anode column is rotatable, and the distance between the anode fins and the cathode fins changes during rotation; the driving power supply is connected to the anode column via a high-voltage transmission line through the tube seat; the thermal pyrolyzer region of the pyrolyzer tube... A catalyst bed is placed on the catalyst bed; the catalyst is 10-30%wt nickel-alumina, 10-30%wt cobalt-alumina, 10-30%wt ruthenium-alumina, iron catalyst, manganese catalyst, palladium catalyst, lanthanum catalyst, molybdenum catalyst, or any combination thereof; a cooling sleeve is installed outside the plasma region of the pyrolysis tube, and a spiral pipe is provided inside the cooling sleeve. The cooling sleeve has a cooling inlet and a cooling outlet at both ends. The cooling inlet is connected to the ammonia fuel supply system. Liquid ammonia flows into the cooling sleeve through the cooling inlet to cool the pyrolysis tube in the plasma region and flows out through the cooling outlet; an insulation sleeve is installed outside the thermal pyrolysis region of the pyrolysis tube to prevent heat loss, and one end of the insulation sleeve has a gas outlet; The heat exchange module has two input terminals and two output terminals, and fins are added to the internal pipes to increase the heat exchange area. The cooling outlet on the cooling sleeve is connected to the first input terminal of the heat exchange module, the first output terminal of the heat exchange module is connected to the air inlet of the pyrolyzer, the air outlet of the pyrolyzer is connected to the second input terminal of the heat exchange module, and the second output terminal of the heat exchange module is connected to the input terminal of the cooling separation chamber. The high-temperature mixed gas of ammonia / hydrogen / nitrogen after pyrolysis is sent to the heat exchange module through the air outlet to recover waste heat. The liquid ammonia flowing out from the cooling outlet is sent to the heat exchange module for preheating and then injected into the pyrolyzer through the air inlet by the ammonia injector for plasma pyrolysis to produce hydrogen. The cooling separation chamber has one input terminal and two output terminals. The second output terminal of the heat exchange module is connected to the input terminal of the cooling separation chamber, the first output terminal of the cooling separation chamber is connected to the ammonia-hydrogen supply terminal, and the second output terminal of the cooling separation chamber is connected to the first input terminal of the heat exchange module. When the cooling separation chamber is neither cooling nor pressurizing, the composition of the cracked mixed gas remains unchanged and is fed into the ammonia-hydrogen supply terminal. Alternatively, the ammonia in the cracked mixed gas is liquefied by cooling to the ammonia liquefaction temperature, or by cooling and pressurizing to the ammonia liquefaction conditions; or the gas is cooled to the nitrogen liquefaction temperature, simultaneously liquefying nitrogen and ammonia, and hydrogen is separated and fed into the ammonia-hydrogen supply terminal. At this time, the atmosphere provided by the ammonia-hydrogen supply terminal is a mixture of hydrogen, nitrogen, and hydrogen, or a mixture of ammonia, hydrogen, and nitrogen. The separated liquid ammonia is fed into the first input terminal of the heat exchange module through the second output terminal of the cooling separation chamber. The control unit regulates the ammonia fuel supply system, the drive power supply, and the heat exchange module for parameterized automatic control of the pyrolysis system. The ammonia fuel supply system is sealed to the pyrolyzer via a stainless steel or carbon steel metal pipe. Liquid ammonia is pumped out from the liquid ammonia storage tank by a liquid ammonia pump, and the liquid ammonia injection pressure is regulated. The liquid ammonia is then sent into the pyrolyzer through the metal pipe. The control unit is connected to the ammonia fuel supply system, the drive power supply, the heat exchange module, and the cooling separation chamber, respectively. It regulates the output flow rate of liquid ammonia, the output power of the drive power supply, the thermal balance of the heat exchange module, and the temperature and pressure of the cooling separation chamber to achieve stable operation of the pyrolysis system and thus obtain the best pyrolysis performance.

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