Ammonia decomposition system using plasma, and ammonia decomposition method using same

Abstract

An ammonia decomposition system according to one embodiment of the present invention comprises: a decomposition device for decomposing ammonia, which comprises a heating member for heating a catalytic reactor and the catalytic reactor containing a decomposition catalyst; a plasma reforming device disposed upstream of the decomposition device so as to reform ammonia; and a reformed gas supply pipe for connecting the plasma reforming device and the decomposition device, and supplying the reformed gas generated in the plasma reforming device to the catalytic reactor and / or the heating member, wherein the plasma reforming device can pyrolyze ammonia by using plasma.

Description

Ammonia decomposition system using plasma and ammonia decomposition method using the same

[0001] The present invention relates to an ammonia decomposition system using plasma for reforming and decomposing ammonia and an ammonia decomposition method using the same.

[0002] Ammonia decomposition is an endothermic reaction (△H = 46.2 kJ / mol), requiring a large amount of heat. Because this reaction occurs at very high temperatures, it is common to use a catalyst for decomposition. When using a precious metal catalyst, such as ruthenium, a temperature of 400 to 500°C is required, while a non-precious metal catalyst requires a temperature of 500 to 600°C or higher.

[0003] In an ammonia decomposition unit, the temperature of the catalytic reactor is raised by a heater or burner. During initial system operation, a considerable amount of time is required for the catalyst to reach its decomposition temperature. Consequently, a significant warm-up time is required for the ammonia decomposition system to operate stably.

[0004] In environments where frequent and periodic startups are required, or where load conditions fluctuate frequently, or in stable systems, a technology that heats the catalyst within a short period of time is required to increase system availability through rapid startup.

[0005] One aspect of the present invention provides an ammonia decomposition system and an ammonia decomposition method using plasma that can shorten the start-up period and rapidly heat a decomposition catalyst.

[0006] An ammonia decomposition system according to one embodiment of the present invention comprises a decomposition device for decomposing ammonia, including a catalytic reactor including a decomposition catalyst and a heating member for heating the catalytic reactor, a plasma reforming device disposed upstream of the decomposition device for reforming ammonia and supplying heat to the decomposition device, and a reforming gas supply pipe connecting the plasma reforming device and the decomposition device and supplying reformed gas generated in the plasma reforming device to the catalytic reactor or the heating member, wherein the plasma reforming device can thermally decompose ammonia using plasma.

[0007] The above plasma reforming device can generate any one plasma selected from the group consisting of direct current arc plasma, alternating current arc plasma, microwave plasma, high-frequency inductively coupled plasma, dielectric barrier discharge (DBD) plasma, pulse plasma, and glow discharge plasma.

[0008] Ammonia can be supplied as a discharge gas to the above plasma reforming device.

[0009] An ammonia decomposition system according to one embodiment of the present invention may further include a temperature measuring unit for measuring the temperature of the catalytic reactor and a control unit for controlling power supplied to the plasma reforming device based on information transmitted from the temperature measuring unit.

[0010] The above control unit can supply power to the plasma reforming device only when the temperature of the catalytic reactor is below a preset reference temperature.

[0011] The above heating element may be formed of an electric heater that generates heat using electricity.

[0012] The above heating element is composed of a fuel burner that burns fuel, the reforming gas supply pipe supplies reforming gas generated in the plasma reforming device to the heating element, and the heating element can supply heat to the catalytic reactor by burning the reforming gas.

[0013] The above heating element includes a plasma burner that generates heat using plasma, and the plasma burner can expand the combustible range of reformed gas and fuel and stabilize the flame through plasma generation.

[0014] An ammonia decomposition system according to one embodiment of the present invention may further include a hydrogen separator for separating hydrogen from decomposition gas discharged from the decomposition device, a circulation supply pipe for supplying byproduct gas or some high-purity hydrogen discharged from the hydrogen separator to the heating element, and a bypass supply pipe for supplying ammonia to the decomposition device by bypassing the plasma reforming device.

[0015] The above plasma reforming device includes a grounded housing having an internal space, and a discharge electrode inserted into the housing and charged with a discharge voltage, and the housing may include a discharge section where the discharge electrode is located, a reaction section where plasma is formed and located downstream of the discharge section, and a variable tube connecting the discharge section and the reaction section, the inner diameter of which gradually decreases as it goes downstream.

[0016] The above plasma reforming device can generate any one plasma selected from the group consisting of direct current arc plasma, alternating current arc plasma, microwave plasma, high-frequency inductively coupled plasma, dielectric barrier discharge plasma, pulse plasma, and glow discharge plasma.

[0017] An ammonia decomposition method according to one embodiment of the present invention may include a plasma reforming step of reforming ammonia using plasma, a reformed gas transfer step of transferring reformed gas generated in the plasma reforming step to a decomposition device, and a catalytic decomposition step of decomposing ammonia into hydrogen and nitrogen using a catalyst in the decomposition device.

[0018] The above plasma reforming step can reform ammonia by supplying power to the plasma reforming device only when the temperature of the catalytic reactor installed in the decomposition device is below a preset reference temperature.

[0019] The ammonia decomposition method according to one embodiment of the present invention may further include a hydrogen separation step for separating hydrogen from the decomposition gas generated in the catalytic decomposition step.

[0020] The above plasma reforming step can supply ammonia as a discharge gas and decompose some or all of the supplied ammonia to generate high-temperature plasma.

[0021] The above decomposition device includes a catalytic reactor including a decomposition catalyst and a heating element that supplies heat to the catalytic reactor, and the catalytic decomposition step can generate high-temperature combustion gas by burning a portion of the reformed gas in the heating element and transfer the heat of the combustion gas to the catalytic reactor.

[0022] The above heating element includes a plasma burner that generates heat using plasma, and the catalytic decomposition step can expand the combustible range of the reformed gas and fuel and stabilize the flame using the plasma burner.

[0023] An ammonia decomposition system according to one embodiment of the present invention includes a plasma reforming device and a reforming gas supply pipe, so that a catalytic reactor can be quickly heated using reforming gas heated in the plasma reforming device.

[0024] FIG. 1 is a drawing illustrating an ammonia decomposition system according to a first embodiment of the present invention.

[0025] FIG. 2 is a drawing illustrating an ammonia decomposition system according to a modified example of the first embodiment of the present invention.

[0026] FIG. 3 is a drawing illustrating an ammonia decomposition system according to another modified example of the first embodiment of the present invention.

[0027] Figure 4 is a graph showing the power supplied to a plasma reforming device according to the first embodiment of the present invention.

[0028] FIG. 5 is a drawing illustrating a plasma reforming device of an ammonia decomposition system according to a second embodiment of the present invention.

[0029] FIG. 6 is a drawing illustrating an ammonia decomposition system according to a third embodiment of the present invention.

[0030] Figure 7 is a flowchart for explaining an ammonia decomposition method according to embodiments of the present invention.

[0031] The present invention is susceptible to various modifications and embodiments. Specific embodiments are illustrated and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0032] The terminology used herein is merely used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In the present invention, it should be understood that the terms "comprise" or "have" are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0033] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Please note that, where possible, identical components are represented by identical reference numerals throughout the drawings. Furthermore, detailed descriptions of well-known functions and configurations that may obscure the gist of the present invention will be omitted. For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted.

[0034] Below, an ammonia decomposition system according to the first embodiment of the present invention is described.

[0035] FIG. 1 is a drawing illustrating an ammonia decomposition system according to a first embodiment of the present invention, FIG. 2 is a drawing illustrating an ammonia decomposition system according to a modified example of the first embodiment of the present invention, and FIG. 3 is a drawing illustrating an ammonia decomposition system according to another modified example of the first embodiment of the present invention.

[0036] Referring to FIGS. 1 to 3, the ammonia decomposition system (100) according to the first embodiment may include a plasma reforming device (110), a decomposition device (120), a hydrogen separator (140), and a control unit (150).

[0037] The ammonia decomposition system (100) is a system that decomposes ammonia using a catalyst and heat to extract hydrogen.

[0038] The plasma reforming device (110) generates plasma to reform ammonia, and hydrogen, nitrogen, and unreacted ammonia can be generated through the decomposition of ammonia. The degree of decomposition of ammonia can be controlled by adjusting the power applied to the plasma reforming device (110).

[0039] The plasma reforming device (110) can generate any one plasma selected from the group consisting of direct current arc plasma, alternating current arc plasma, microwave plasma, high-frequency inductively coupled plasma, dielectric barrier discharge (DBD) plasma, pulse plasma, and glow discharge plasma. In addition, the plasma reforming device (110) can generate not only high-temperature plasma but also low-temperature plasma.

[0040] Ammonia is supplied as a discharge gas to the plasma reforming device (110), and the ammonia can be decomposed into ions by an arc, high frequency, etc. to form plasma.

[0041] An ammonia supply pipe (L11) for supplying ammonia may be connected to the plasma reforming device (110). The ammonia supply pipe (L11) may supply ammonia in a gaseous state to the plasma reforming device (110).

[0042] Meanwhile, a reforming gas supply pipe (L12) that supplies reforming gas generated in the plasma reforming device (110) to the decomposition device (120) may be connected to the plasma reforming device (110). The reforming gas supply pipe (L12) may be connected to a catalytic reactor (121) or a heating element (123). The reforming gas supply pipe (L12) may be branched and connected to both the catalytic reactor (121) and the heating element (123).

[0043] Additionally, a direct supply pipe (L15) for supplying reformed gas to a hydrogen separator (140) may be installed in the plasma reforming device (110). When ammonia is sufficiently decomposed in the plasma reforming device (110), the reformed gas may be supplied directly to the hydrogen separator (140) by bypassing the decomposition device (120) through the direct supply pipe (L15).

[0044] The decomposition device (120) may include a catalytic reactor (121) and a heating element (123). The catalytic reactor (121) includes a plurality of decomposition catalysts, which may be formed of a precious metal catalyst or a non-precious metal catalyst. The decomposition catalyst may be formed in the form of beads or cartridges. The decomposition catalyst may include a support and a catalyst layer coated on the support, and various structures and materials that decompose ammonia may be applied.

[0045] The catalytic reactor (121) decomposes reformed gas or ammonia to produce decomposition gas, and the decomposition gas can be delivered to a hydrogen separator (140) through a decomposition gas transfer pipe (L16). The decomposition gas can contain hydrogen, nitrogen, and unreacted ammonia.

[0046] The heating element (123) supplies heat to the catalytic reactor (121) and may be formed of an electric heater. The heating element (123) may generate heat by electric resistance heating or by induction heating. A reforming gas supply pipe (L12) that supplies reforming gas generated in a plasma reforming device (110) to the catalytic reactor (121) may be connected to the catalytic reactor (121). The reforming gas heated in the plasma reforming device (110) can heat the catalyst to a high temperature.

[0047] In addition, as illustrated in FIGS. 2 and 3, the heating element (123) may be configured as a burner that generates heat by burning fuel. In this case, a reformed gas supply pipe (L12) is connected to the heating element (123) to supply reformed gas to the heating element (123). When the reformed gas supply pipe (L12) is connected to the heating element (123), reformed gas containing hydrogen, nitrogen, and ammonia can be stably combusted in the heating element (123) to supply heat to the catalytic reactor (121).

[0048] In addition, the reformed gas supply pipe (L12) is connected to the catalytic reactor (121) and the heating element (123), and some of the reformed gas is supplied to the heating element (123) and combusted, and the remaining reformed gas is supplied to the catalytic reactor (121) and can be decomposed after heating the catalyst.

[0049] The hydrogen separator (140) receives the decomposition gas from the decomposition device (120) and separates hydrogen, byproduct gas, and unreacted ammonia. The hydrogen separator (140) can separate hydrogen using the pressure swing adsorption (PSA) method, and can also separate hydrogen using a hydrogen separation membrane. The hydrogen separator (140) can be configured in various structures, and the present invention is not limited thereto.

[0050] The hydrogen separated in the hydrogen separator (140) can be transferred to a storage through a pipe or supplied to a consumer. Meanwhile, the by-product gas separated in the hydrogen separator (140) and some of the separated hydrogen can be supplied to a heating element (123) formed of a burner. A circulation supply pipe (L13) is installed between the hydrogen separator (140) and the heating element (123), and the circulation supply pipe (L13) transfers the by-product gas discharged from the hydrogen separator (140) to the heating element (123).

[0051] Meanwhile, a bypass supply pipe (L14) is installed in the decomposition device (120) to supply ammonia to the decomposition device (120) by bypassing the plasma reforming device (110). The bypass supply pipe (L14) connects the ammonia supply pipe (L11) and the decomposition device (120), and the bypass supply pipe (L14) can supply ammonia to the catalytic reactor (121) or to the catalytic reactor (121) and the heating element (123).

[0052] A temperature sensor (125) for measuring the temperature inside the catalytic reactor (121) may be installed in the catalytic reactor (121). Temperature information measured by the temperature sensor (125) is transmitted to the control unit (150), and the control unit (150) controls the valves based on the information transmitted from the temperature sensor. A first valve (161) may be installed in the ammonia supply pipe (L11), and a second valve (162) may be installed in the bypass supply pipe (L14).

[0053] When the temperature of the catalytic reactor (121) is lower than or equal to a preset reference temperature, the control unit (150) can open the first valve (161) to supply reformed ammonia having a high temperature to the catalytic reactor (121) and the heating element (123) through the plasma reforming device (110). Meanwhile, when the temperature of the catalytic reactor (121) is higher than or equal to a preset reference temperature, the control unit (150) can adjust the first valve (161) to reduce the flow rate of ammonia supplied to the plasma reforming device (100) and adjust the second valve (162) to supply more ammonia to the decomposition device (120). Here, the reference temperature varies depending on the decomposition catalyst used, and can be 400°C to 600°C at which ammonia is sufficiently decomposed.

[0054] As illustrated in FIG. 4, when the temperature of the catalytic reactor (121) is lower than the reference temperature at the beginning of the start-up, the control unit (150) can open the first valve (161) and supply high power to the plasma reformer (110). Meanwhile, when the temperature of the catalytic reactor (121) is heated to a temperature higher than the reference temperature, the control unit (150) can reduce the supply of ammonia through the first valve (161) and also reduce the power supply to the plasma reformer (110). In addition, when the temperature of the catalytic reactor (121) becomes lower than the reference temperature during operation, the first valve (161) can be opened and the power of the plasma reformer (110) can be increased to produce hydrogen through high-temperature reformed ammonia and increase the temperature of the catalytic reactor (121).

[0055] A third valve (163) may be installed in the reforming gas supply pipe (L12), and a fourth valve (164) may be installed in the direct supply pipe (L15). A concentration sensor (115) for measuring the concentration of hydrogen contained in the reforming gas generated in the plasma reforming device (110) is installed in the plasma reforming device (110), and the control unit (150) may control the opening and closing of the third valve (163) and the fourth valve (164) based on information transmitted from the concentration sensor (115).

[0056] When the concentration of hydrogen contained in the reformed gas is lower than or equal to a preset reference concentration, the control unit (150) opens the third valve (163) and closes the fourth valve (164) to supply the reformed gas to the decomposition device (120). Meanwhile, when the concentration of hydrogen contained in the reformed gas is higher than or equal to a preset reference concentration, the control unit (150) closes the third valve (163) and opens the fourth valve (164) to supply the reformed gas to the hydrogen separator (140).

[0057] FIG. 5 is a drawing illustrating a plasma reforming device of an ammonia decomposition system according to a second embodiment of the present invention.

[0058] Referring to FIG. 5, the ammonia decomposition system according to the second embodiment has the same structure as the ammonia decomposition system according to the first embodiment described above, except for the plasma reforming device (110), so a duplicate description of the same configuration is omitted.

[0059] The plasma reforming device (110) according to the second embodiment may be configured as an arc plasma device that generates plasma using an arc. However, the present invention is not limited thereto, and the plasma reforming device may be configured in various structures.

[0060] A plasma reforming device (110) according to the present embodiment may include a housing (10) having an internal space and a discharge electrode (20) inserted into the housing (10). The plasma reforming device (110) generates plasma using an arc (AC) and reforms ammonia fuel by supplying it to an area where plasma is formed.

[0061] The housing (10) is formed in a tubular shape with an internal space and can be grounded. The housing (10) can include a discharge section (12) where a discharge electrode (20) is positioned and a reaction section (13) located downstream of the discharge section (12) where plasma is formed. The reaction section (13) has an inner diameter smaller than that of the discharge section (12), and a variable tube (15) whose inner diameter gradually decreases as it goes downstream can be positioned between the discharge section (12) and the reaction section (13).

[0062] The discharge electrode (20) is inserted into the housing (10) and can extend in the longitudinal direction of the housing (10). The discharge electrode (20) can be charged with a preset discharge voltage, and a direct current or alternating current power source can be connected to the discharge electrode (20).

[0063] In the housing (10), a supply member (16) is formed in the discharge unit (12) to supply discharge gas containing ammonia, and the supply member (16) can inject air and oxygen together with ammonia into the inside of the housing. The supply member (16) can inject gas in an eccentric direction with respect to the center of the housing (10) to form a swirl. Accordingly, the arc (AC) can rotate. The supply member (16) is located on the outside of the discharge electrode (20) and can inject gas to the outer surface of the discharge electrode (20), and the discharge gas can move while rotating along the outer surface of the discharge electrode.

[0064] An arc (AC) is formed between a discharge electrode (20) and a housing (10). The first arc point (P1) may be located at the tip of the discharge electrode (20), and the second arc point (P2) may be located at the part where the variable tube (15) and the reaction section (13) are connected. In addition, a high-temperature plasma region (PA1) is formed in the reaction section.

[0065] FIG. 6 is a drawing illustrating an ammonia decomposition system according to a third embodiment of the present invention.

[0066] Referring to FIG. 6, the ammonia decomposition system according to the third embodiment has the same structure as the ammonia decomposition system according to the first embodiment described above, except for the heating element (126), so a duplicate description of the same configuration is omitted.

[0067] The heating element (126) may include a plasma burner that generates heat by burning fuel. The heating element (126) may be connected to a reformed gas supply pipe (L12) to receive reformed gas from the reformed gas supply pipe (L12), and may be connected to a circulation supply pipe (L13) to receive by-product gas discharged from the hydrogen separator (140) and some hydrogen from the circulation supply pipe (L13).

[0068] A plasma burner can generate arc plasma, and may be configured as a gliding arc plasma device. However, the present invention is not limited thereto, and the plasma burner may be configured as a device that generates various types of high-temperature plasma.

[0069] The plasma burner can be operated using air and external fuel. In one embodiment, the plasma burner is connected to a reformed gas supply pipe (L12) to receive reformed gas from the reformed gas supply pipe (L12), and is connected to a circulation supply pipe (L13) to receive by-product gas discharged from the hydrogen separator (140) and some hydrogen from the circulation supply pipe (L13).

[0070] Plasma burners can extend the combustible range of reformed gases and fuels and stabilize flames.

[0071] Below, a method for decomposing ammonia according to embodiments of the present invention is described.

[0072] Figure 7 is a flowchart for explaining an ammonia decomposition method according to embodiments of the present invention.

[0073] Referring to FIGS. 1 to 6, the ammonia decomposition method according to the present embodiment may include a plasma reforming step (S101), a reformed gas transfer step (S102), a catalytic decomposition step (S103), and a hydrogen separation step (S104).

[0074] The plasma reforming step (S101) uses plasma to thermally decompose ammonia and generate a reformed gas. The plasma reforming step (S101) can generate any one plasma selected from the group consisting of direct current arc plasma, alternating current arc plasma, microwave plasma, high-frequency inductively coupled plasma, dielectric barrier discharge (DBD) plasma, pulse plasma, and glow discharge plasma. The plasma reforming step (S101) can generate not only high-temperature plasma but also low-temperature plasma.

[0075] The plasma reforming step (S101) can reform ammonia by supplying power to the plasma reforming device (110) only when the temperature of the catalytic reactor (121) installed in the decomposition device (120) is below a preset reference temperature. In addition, the plasma reforming step (S101) can generate plasma by supplying ammonia as a discharge gas and decomposing and ionizing the ammonia.

[0076] The reforming gas delivery step (S102) supplies the reforming gas generated in the plasma reforming device (110) to the decomposition device (120) using the reforming gas supply pipe (L12).

[0077] The catalytic decomposition step (S103) can decompose the reformed gas supplied in the plasma reforming step (S101) in a catalytic reactor (121) to produce a decomposition gas containing hydrogen and nitrogen.

[0078] In addition, the catalytic decomposition step (S103) generates high-temperature combustion gas by burning the reformed gas supplied in the plasma reforming step (S101) in a heating element (123) and supplies the combustion gas to a catalytic reactor (121). Separate ammonia may also be supplied to the catalytic reactor (121).

[0079] In addition, the catalytic decomposition step (S103) may be configured to combust a portion of the reformed gas supplied from the plasma reforming step (S101) and containing hydrogen, nitrogen, and un-decomposed ammonia in a heating element (123) to generate high-temperature combustion gas, and supply the combustion heat to the catalytic reactor (121) through a heat exchange method, or supply the combustion gas directly to the catalytic reactor (121). In addition, the catalytic decomposition step (S103) may also supply a portion of the reformed gas to the catalytic reactor (121).

[0080] The catalytic decomposition step (S103) transfers reformed gas from the plasma reforming device (110) to the fuel burner through the reformed gas supply pipe (L12), supplies by-product gas and some hydrogen to the fuel burner through the circulation supply pipe (L13), combusts them to generate heat, and transfers the generated heat to the catalytic reactor (121).

[0081] In addition, the catalytic decomposition step (S103) can expand the combustible range of the reformed gas and fuel and stabilize the flame by delivering the reformed gas to the plasma burner from the plasma reforming device (110) through the reformed gas supply pipe (L12) and supplying the by-product gas and some hydrogen to the plasma burner through the circulation supply pipe (L13).

[0082] The hydrogen separation step (S104) separates hydrogen contained in the decomposition gas generated in the decomposition device (120), and hydrogen can be separated in various ways, such as a pressure swing adsorption method. The hydrogen separation step (S104) separates hydrogen from the decomposition gas and can transfer the remaining byproduct gas and some of the hydrogen to the heating element (123).

[0083] Above, one embodiment of the present invention has been described, but a person having ordinary skill in the art will be able to modify and change the present invention in various ways by adding, changing, deleting or adding components, etc., within the scope that does not depart from the spirit of the present invention described in the claims, and this will also be considered to be included within the scope of the rights of the present invention.

[0084] (Explanation of symbols)

[0085] 100: Fuel reforming system 110: Plasma reforming device

[0086] 120: Decomposition device 121: Catalytic reactor

[0087] 123, 126: Heating element 125: Temperature sensor

[0088] 140: Hydrogen separator 10: Housing

[0089] 20: Discharge electrode

Claims

1. A decomposition device for decomposing ammonia, including a catalytic reactor containing a decomposition catalyst and a heating element for heating the catalytic reactor; A plasma reforming device positioned upstream of the above decomposition device to reform ammonia and supply heat to the above decomposition device; and A reformed gas supply pipe connecting the plasma reforming device and the decomposition device and supplying reformed gas generated in the plasma reforming device to at least one of the catalytic reactor and the heating element; The above plasma reforming device is an ammonia decomposition system that uses plasma to thermally decompose ammonia.

2. In paragraph 1, The above plasma reforming device is an ammonia decomposition system using plasma that generates any one plasma selected from the group consisting of direct current arc plasma, alternating current arc plasma, microwave plasma, high-frequency inductively coupled plasma, dielectric barrier discharge plasma, pulse plasma, and glow discharge plasma.

3. In paragraph 1, The above plasma reforming device is an ammonia decomposition system using plasma in which ammonia is supplied as a discharge gas.

4. In paragraph 1, An ammonia decomposition system using plasma, further comprising a temperature measuring unit for measuring the temperature of the catalytic reactor and a control unit for controlling power supplied to the plasma reforming device based on information transmitted from the temperature measuring unit.

5. In paragraph 4, The above control unit is an ammonia decomposition system using plasma that supplies power to the plasma reforming device when the temperature of the catalytic reactor is below a preset reference temperature.

6. In paragraph 1, The above heating element is an ammonia decomposition system using plasma including an electric heater that generates heat using electricity.

7. In paragraph 1, The above heating element includes a fuel burner that burns fuel, The above reforming gas supply pipe supplies reforming gas generated in the plasma reforming device to the heating element, The above heating element is an ammonia decomposition system using plasma that supplies heat to the catalytic reactor by burning the reformed gas.

8. In paragraph 1, The above heating element includes a plasma burner that generates heat using plasma, The above plasma burner is an ammonia decomposition system that uses plasma to expand the combustible range of reformed gas and fuel and stabilize the flame through plasma generation.

9. In paragraph 7, A hydrogen separator that separates hydrogen from the decomposition gas discharged from the above decomposition device; A circulation supply pipe that supplies the by-product gas or part of the hydrogen discharged from the hydrogen separator to the heating element, and An ammonia decomposition system using plasma further comprising a bypass supply pipe for supplying ammonia to the decomposition device by bypassing the plasma reforming device.

10. In paragraph 1, The plasma reforming device comprises a grounded housing having an internal space, and a discharge electrode inserted into the housing and charged with a discharge voltage, The above housing is an ammonia decomposition system using plasma, which includes a discharge section where the discharge electrode is located, a reaction section located downstream of the discharge section where plasma is formed, and a variable tube connecting the discharge section and the reaction section and having an inner diameter that gradually decreases as it goes downstream.

11. Plasma reforming step for reforming ammonia using plasma; A reformed gas transfer step for transferring the reformed gas generated in the above plasma reforming step to a decomposition device; and An ammonia decomposition method comprising a catalytic decomposition step of decomposing ammonia into hydrogen and nitrogen using a catalyst in a decomposition device.

12. In paragraph 11, The above plasma reforming step is an ammonia decomposition method for reforming ammonia by supplying power to the plasma reforming device when the temperature of the catalytic reactor installed in the decomposition device is below a preset reference temperature.

13. In paragraph 11, An ammonia decomposition method further comprising a hydrogen separation step for separating hydrogen from the decomposition gas generated in the above catalytic decomposition step.

14. In paragraph 11, The above plasma reforming step is an ammonia decomposition method that supplies ammonia as a discharge gas and decomposes part or all of the supplied ammonia to generate plasma.

15. In paragraph 11, The above decomposition device includes a catalytic reactor containing a decomposition catalyst and a heating element that supplies heat to the catalytic reactor, The above catalytic decomposition step is an ammonia decomposition method in which a portion of the reformed gas is combusted in the heating element to generate high-temperature combustion gas and the heat of the combustion gas is transferred to the catalytic reactor.

16. In paragraph 15, The above heating element includes a plasma burner that generates heat using plasma, The above catalytic decomposition step is an ammonia decomposition method that expands the combustible range of reformed gas and fuel and stabilizes the flame using the plasma burner.

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