Ammonia decomposition facility

Abstract

This ammonia decomposition facility comprises: a light collection device; an ammonia decomposition device; a detection device; and a control device. The light collection device collects sunlight. An ammonia decomposition unit decomposes ammonia using, as a heat source, the sunlight collected by the light collection device to generate hydrogen. The detection device detects at least one physical quantity selected from the group consisting of the irradiation quantity of sunlight and the temperature of the ammonia decomposition device. The control device controls the quantity of ammonia supplied to the ammonia decomposition device according to the physical quantity detected by the detection device.

Description

Ammonia decomposition equipment

[0001] The present disclosure relates to ammonia decomposition equipment. This application claims priority based on Japanese Patent Application No. 2024-175154 filed on October 4, 2024, and incorporates all the descriptions described in the above Japanese application.

[0002] Hydrogen production equipment (ammonia decomposition equipment) including a reaction vessel containing a supported catalyst, a supply unit for supplying ammonia to the reaction vessel, and a microwave irradiator for irradiating microwaves into the reaction vessel is known (see Patent Document 1 below). In the hydrogen production apparatus described in Patent Document 1, the reaction vessel generates heat based on the irradiation of microwaves, and ammonia contacts the supported catalyst in the reaction vessel and is decomposed. Then, hydrogen and nitrogen are produced.

[0003] Japanese Patent Application Laid-Open No. 2022-47644

[0004] There is a need for ammonia decomposition equipment that can decompose ammonia at low cost while reducing the amount of undissociated ammonia.

[0005] The present disclosure provides ammonia decomposition equipment that can decompose ammonia at low cost while reducing the amount of undissociated ammonia.

[0006] The ammonia decomposition equipment of the present disclosure includes a condenser, an ammonia decomposition device, a detection device, and a control device. The condenser collects sunlight. The ammonia decomposition unit decomposes ammonia using the sunlight collected by the condenser as a heat source to generate hydrogen. The detection device detects at least one physical quantity selected from the group consisting of the irradiation amount of sunlight and the temperature of the ammonia decomposition device. The control device controls the amount of ammonia supplied to the ammonia decomposition device according to the physical quantity detected by the detection device.

[0007] The ammonia decomposition equipment of the present disclosure can decompose ammonia at low cost while reducing the amount of undissociated ammonia.

[0008] Figure 1 is a schematic diagram of a specific example of an embodiment of the ammonia decomposition equipment of the present disclosure. Figure 2 is a cross-sectional view of the ammonia decomposition apparatus in the ammonia decomposition equipment shown in Figure 1. Figure 3 is a perspective view of the ammonia decomposition section in the ammonia decomposition apparatus shown in Figure 2. Figure 4A is a cross-sectional view of a partition wall in the ammonia decomposition section shown in Figure 3. Figure 4B is a cross-sectional view of a partition wall (another specific example) in the ammonia decomposition section shown in Figure 3. Figure 5 is a cross-sectional view of the ammonia decomposition apparatus of the first modified example. Figure 6 is a cross-sectional view of the ammonia decomposition apparatus of the second modified example. Figure 7 is a perspective view of the ammonia decomposition section of the third modified example. Figure 8 is an enlarged cross-sectional view of the ammonia decomposition section of the fourth modified example.

[0009] [Outline of Embodiments] (1) The ammonia decomposition equipment of this disclosure comprises a light concentrator, an ammonia decomposition unit, a detection device, and a control device. The light concentrator collects sunlight. The ammonia decomposition unit uses the sunlight collected by the light concentrator as a heat source to decompose ammonia and generate hydrogen. The detection device detects at least one physical quantity selected from the group consisting of the amount of sunlight irradiation and the temperature of the ammonia decomposition unit. The control device controls the amount of ammonia supplied to the ammonia decomposition unit according to the physical quantity detected by the detection device.

[0010] The ammonia decomposition unit uses sunlight collected by a light concentrator as a heat source to decompose ammonia. Therefore, compared to the configuration described in Patent Document 1, which uses microwaves as a heat source, the ammonia decomposition equipment of this disclosure can obtain the heat necessary for ammonia decomposition from sunlight, thus enabling ammonia decomposition at a lower cost.

[0011] The amount of sunlight irradiated fluctuates. In conjunction with this, the temperature of the ammonia decomposition device also fluctuates. In particular, when there are clouds between the sun and the concentrator (when the weather changes from clear to cloudy), the amount of radiation at the concentrator decreases rapidly, and the temperature of the ammonia decomposition device also decreases. As a result, the efficiency of ammonia decomposition decreases, and undecomposed ammonia is discharged.

[0012] However, in the ammonia decomposition equipment of this disclosure, the control device controls the amount of ammonia supplied to the ammonia decomposition unit according to the physical quantity detected by the detection device. Therefore, even if the amount of sunlight irradiation decreases and the temperature of the ammonia decomposition unit decreases, the amount of ammonia supplied to the ammonia decomposition unit is reduced, thereby reducing the amount of undecomposed ammonia. When the amount of sunlight irradiation increases, the amount of ammonia supplied to the ammonia decomposition unit can be increased, thereby increasing the amount of ammonia decomposed.

[0013] (2) In (1) above, the light concentrator may include a reflector that reflects sunlight and concentrates it in the ammonia decomposition section. In this ammonia decomposition equipment, the reflector makes it easy and reliable to irradiate the ammonia decomposition section with sunlight.

[0014] (3) In (2) described above, the reflector may be a parabolic dish type with a focal point, or a parabolic trough type with a focal line.

[0015] (4) In (2) described above, the reflector may be a parabolic dish type with a focal point. In this ammonia decomposition apparatus, the energy density of the ammonia decomposition section can be increased to improve the ammonia decomposition efficiency per unit volume.

[0016] (5) In (1) above, the ammonia decomposition section may include a catalyst. With this ammonia decomposition equipment, the ammonia decomposition efficiency per unit volume can be increased.

[0017] (6) In (5) described above, the ammonia decomposition section has a honeycomb structure having a plurality of channels through which ammonia can pass in a first direction, and a plurality of channels extending from a first edge of the ammonia decomposition section in the first direction toward a second edge located away from the first edge, and the honeycomb structure includes an outer peripheral wall extending from the first edge to the second edge, and a partition wall extending from the first edge toward the second edge and supported by the outer peripheral wall, which divides the internal space of the outer peripheral wall into a plurality of channels, and the catalyst may be placed on the wall surface of the partition wall.

[0018] (7) In (5) above, the ammonia decomposition section has a honeycomb structure having a plurality of channels through which ammonia can pass in a first direction, and a plurality of channels extending from a first edge of the ammonia decomposition section in the first direction toward a second edge located away from the first edge, and the honeycomb structure includes an outer peripheral wall extending from the first edge to the second edge, and a partition wall extending from the first edge toward the second edge and supported by the outer peripheral wall, which partitions the internal space of the outer peripheral wall into a plurality of channels, and the partition wall may contain a catalyst.

[0019] (8) In (6) or (7) above, the partition wall may include a first wall having a first thickness and extending from a first edge toward a second edge, and a second wall which is a heat storage section having a second thickness greater than the first thickness and extending from the first edge toward the second edge. In this ammonia decomposition equipment, even if the amount of sunlight irradiation decreases rapidly, the second wall which is a heat storage section can store the heat based on the sunlight before the reduction, so that the temperature change of the ammonia decomposition section can be reduced.

[0020] (9) In (6) or (7) above, the ammonia decomposition section may include a first part formed from a first material having a first specific heat and a second part which is a heat storage section. The second part is formed from a second material having the same specific heat as the first specific heat or a second specific heat that is higher than the first specific heat. In this ammonia decomposition apparatus, even if the amount of sunlight irradiation decreases rapidly, the second part which is a heat storage section can store heat based on the sunlight before the reduction, so that the temperature change of the ammonia decomposition section can be reduced.

[0021] (10) In (6) or (7) above, the partition wall may include a third wall that is radial with respect to the optical axis of the sunlight collected by the light concentrator, and a plurality of fourth walls arranged concentrically with respect to the optical axis of the sunlight. As you move outward from the optical axis of the sunlight collected by the light concentrator, the angle between the sunlight and the optical axis increases. As a result, sunlight that is separated from the optical axis and has entered the first edge does not easily penetrate deeply from the first edge towards the second edge (deep part). Consequently, such sunlight is not easily utilized as a heat source. However, in the ammonia decomposition equipment of this disclosure, if the spacing between the fourth walls is increased, as you move outward from the optical axis, there are fewer walls blocking the light that spreads circumferentially, so the above-mentioned sunlight can penetrate deeply from the first edge towards the second edge (deep part). On the other hand, even if the distance between the third walls is shortened, it does not significantly block light, and by shortening the distance between the third walls, the catalyst loading density per unit volume of the ammonia decomposition section does not decrease. Therefore, the sunlight mentioned above is effectively utilized as a heat source. As a result, the ammonia decomposition efficiency in the ammonia decomposition section can be increased.

[0022] (11) In (5) described above, the ammonia decomposition section has a foam structure consisting of pillars that are connected to each other and a continuous internal space formed by the pillars, through which ammonia can pass, and a catalyst may be placed on the surface of the pillars. In this ammonia decomposition apparatus, ammonia flows through the internal space in contact with the catalyst and is decomposed.

[0023] (12) In (5) above, the ammonia decomposition section has a foam structure consisting of pillars that are connected to each other and a continuous internal space formed by the pillars, through which ammonia can pass, and the pillars may contain a catalyst. In this ammonia decomposition apparatus, ammonia flows through the internal space in contact with the catalyst and is decomposed.

[0024] (13) In (5) above, the ammonia supplied to the ammonia decomposition device may be ammonia gas.

[0025] [Specific Examples of Embodiments] Specific examples of the ammonia decomposition equipment of the present disclosure will be described with reference to Figures 1 to 4B. Figure 1 is a schematic diagram of a specific example of an embodiment of the ammonia decomposition equipment of the present disclosure. Figure 2 is a cross-sectional view of the ammonia decomposition apparatus in the ammonia decomposition equipment shown in Figure 1. Figure 3 is a perspective view of the ammonia decomposition section shown in Figure 2. Figure 4A is a cross-sectional view of a partition wall in the ammonia decomposition section shown in Figure 3. Figure 4B is a cross-sectional view of a partition wall (another specific example) in the ammonia decomposition section shown in Figure 3.

[0026] As shown in Figure 1, the ammonia decomposition equipment 1 comprises a light concentrator 2, an ammonia decomposition unit 3, a supply line 4, a discharge line 5, a detection device 6, and a control device 7.

[0027] [Concentrating device 2] The concentrating device 2 collects sunlight. The concentrating device 2 includes a reflector 21. Examples of reflectors 21 include parabolic dish type, parabolic trough type, condensing tower type, and beam-down type. Preferably, the reflector 21 is a parabolic dish type having a focal point FP, or a parabolic trough type having a focal line FL. A parabolic trough type reflector 21 is, for example, a rectangular flat plate in which two opposing sides are curved so that they approach each other. The focal line FL of the parabolic trough type reflector 21 is parallel to the two sides mentioned above. More preferably, the reflector 21 is a parabolic dish type having a focal point FP. Note that a parabolic trough type or parabolic dish type reflector 21 may be formed by connecting (arranging) a plurality of flat plates to create a pseudo-curved surface.

[0028] Furthermore, the light-gathering device 2 may include a tracking device 22. The tracking device 22 is configured to swing the reflector 21 horizontally and to swing so that its elevation angle can be changed, so that the reflector 21 faces the moving sun.

[0029] [Ammonia Decomposition Apparatus 3] As shown in Figure 2, the ammonia decomposition apparatus 3 includes a container 31, a window 32, and an ammonia decomposition unit 33. The container 31 fixes the ammonia decomposition unit 33 and the window 32. The container 31 houses the ammonia decomposition unit 33. A supply passage 311 and a discharge passage 312 are formed in the container 31. The window 32 is positioned between the reflector 21 (see Figure 1) and the ammonia decomposition unit 33. The window 32 is transparent to sunlight. The window 32 faces a part of the supply passage 311. The window 32 is configured so that ammonia gas flowing through the supply passage 311 does not pass through.

[0030] The ammonia decomposition unit 33 uses the heat generated by absorbing sunlight collected by the light concentrator 2 as a heat source to decompose ammonia and produce hydrogen. The ammonia decomposition unit 33 is located between the outlet of the supply passage 311 and the inlet of the discharge passage 312.

[0031] As shown in Figures 2 and 3, the ammonia decomposition unit 33 has a honeycomb structure 331. The honeycomb structure 331 has a plurality of flow channels 332. Ammonia can pass through the plurality of flow channels 332 in a first direction D1. The plurality of flow channels 332 extend from a first edge 333 to a second edge 334 of the ammonia decomposition unit 33 in the first direction D1. The end of the region of the flow channel 332 near the first edge 333 faces the supply passage 311. The second edge 334 is located away from the first edge 333. The end of the region of the flow channel 332 near the second edge 334 faces the discharge passage 312.

[0032] The honeycomb structure 331 includes an outer perimeter wall 336 and partition walls 337. The outer perimeter wall 336 extends from a first edge 333 to a second edge 334. The outer perimeter wall 336 has a cylindrical shape with its central axis parallel to a first direction D1. The partition walls 337 extend from the first edge 333 toward the second edge 334. The partition walls 337 are supported by the outer perimeter wall 336. The partition walls 337 divide the internal space of the outer perimeter wall 336 into a plurality of flow channels 332. In this disclosure, as shown in Figure 3, the partition walls 337 have a grid shape in a cross section perpendicular to the first direction D1. The partition walls 337 are sometimes referred to as ribs.

[0033] As shown in Figure 4A, the ammonia decomposition section 33 (see Figure 3) includes a catalyst 338. The catalyst 338 is arranged on the wall surface of the partition wall 337. In other words, the catalyst 338 is supported on the wall surface of the partition wall 337. The catalyst 338 may be arranged in layers on the wall surface. The outer peripheral wall 336 and the partition wall 337 are formed from, for example, a heat-resistant material. Examples of heat-resistant materials include ceramics. The ceramic is not limited. For example, the ceramic includes at least one of oxides, carbides, and nitrides. Furthermore, the ceramic may be an oxide, carbide, or nitride impregnated with a metal. Preferably, the ceramic is silicon carbide impregnated with metallic silicon. As the catalyst 338, a nickel-based catalyst or a ruthenium-based catalyst can be used. In addition, nickel and calcium imide or barium titanate can be used in combination as the catalyst 338.

[0034] On the other hand, as shown in Figure 4B, the catalyst 338 may be contained within the partition wall 337. That is, the partition wall 337 may contain the catalyst 338. The catalyst 338 is disposed, for example, in particulate form within the ceramic. On the other hand, although not shown, the catalyst 338 and the ceramic may form a homogeneous phase.

[0035] [Supply Line 4] As shown in Figure 1, supply line 4 supplies ammonia to the ammonia decomposition unit 3. Specifically, supply line 4 supplies ammonia gas to the ammonia decomposition unit 33. Supply line 4 is connected to the supply path 311 (see Figure 2) of the ammonia decomposition unit 3.

[0036] [Discharge Line 5] Discharge line 5 discharges the decomposition gas from the ammonia decomposition unit 3. The decomposition gas contains hydrogen (hydrogen gas) and nitrogen (nitrogen gas) produced by the decomposition of ammonia in the ammonia decomposition unit 3. The decomposition gas may also contain undecomposed ammonia (ammonia gas). Discharge line 5 is connected to the discharge passage 312 (see Figure 2) of the ammonia decomposition unit 3. Heat exchangers that can exchange heat with each other may be provided in the middle of the supply line 4 and the discharge line 5.

[0037] [Detection device 6] The detection device 6 detects at least one physical quantity selected from the group consisting of the amount of sunlight irradiation and the temperature of the ammonia decomposition unit 3. As shown in Figures 1 and 2, the detection device 6 includes an illuminometer 6A or a thermometer 6B. The detection device 6 may include both an illuminometer 6A and a thermometer 6B. The illuminometer 6A detects the amount of sunlight irradiation. Examples of illuminometers 6A include a first illuminometer 61 located on the surface of the reflector 21 (see Figure 1), a second illuminometer 62 located between the reflector 21 and the window 32 (see dashed line in Figure 2), and a third illuminometer 63 located on the surface of the first edge 333 of the ammonia decomposition unit 33 (see Figure 2). The second illuminometer 62 is located on the opposite side of the ammonia decomposition unit 33 as seen from the window 32.

[0038] As shown in Figure 2, the thermometer 6B detects the temperature of the ammonia decomposition apparatus 3. For example, the thermometer 6B detects the temperature of the ammonia decomposition section 33, or the temperature in the vicinity of the ammonia decomposition section 33 (for example, a position about 1 mm away from the ammonia decomposition section 33). Examples of the thermometer 6B include a first thermometer 65 located on the surface of the first edge 333 of the ammonia decomposition section 33, and a second thermometer 66 (dummy line) located in the partition wall 337 between the first edge 333 and the second edge 334.

[0039] [Control device 7] As shown in Figure 1, the control device 7 controls the amount of ammonia supplied to the ammonia decomposition device 3 according to the physical quantity detected by the detection device 6. The control device 7 is connected to the detection device 6. The control device 7 is located, for example, in the supply line 4. A valve can be used as the control device 7. The valve's opening degree can be adjusted (changed).

[0040] [Operation of Ammonia Decomposition Plant 1] As shown in Figures 1 and 2, in the ammonia decomposition plant 1, sunlight is concentrated in the ammonia decomposition section 33 by the light concentrator 2, and the ammonia decomposition section 33 is heated. Ammonia gas is supplied to the ammonia decomposition section 33 from the supply line 4 via the supply passage 311. If the weather is fine, the valve of the control device 7 is, for example, fully open. The ammonia gas (all or part of it) comes into contact with the heated catalyst and is decomposed into hydrogen gas and nitrogen gas. The decomposition gas, including hydrogen gas and nitrogen gas, is discharged from the discharge line 5 via the discharge passage 312.

[0041] When the amount of sunlight irradiating the ammonia decomposition unit 3 decreases (for example, from clear skies to cloudy skies), the illuminance meter 6A in the detection device 6 detects the decrease in sunlight irradiance. The thermometer 6B in the detection device 6 detects a decrease in the temperature of the ammonia decomposition unit 33. Then, a signal is sent from the detection device 6 to the control device 7 according to the above physical quantities. Based on the signal sent from the detection device 6, the control device 7 throttles the valve (reduces the opening). As a result, the amount of ammonia gas supplied from the supply line 4 to the ammonia decomposition unit 3 decreases. The amount of undecomposed ammonia gas in the ammonia decomposition unit 3 does not increase (it can be reduced).

[0042] [First Modified Example] A first modified example of the ammonia decomposition apparatus 1 will be described with reference to Figure 5. Figure 5 is a cross-sectional view of the ammonia decomposition apparatus of the first modified example.

[0043] The partition wall 337 includes a first wall 3371 and a second wall 3372. The first wall 3371 extends from a first edge 333 toward a second edge 334. The first wall 3371 has a first thickness T1. The first thickness T1 is the same from the first edge 333 toward the second edge 334.

[0044] The second wall 3372 extends from the first edge 333 towards the second edge 334. The second wall 3372 has a second thickness T2. The second thickness T2 is the same from the first edge 333 to the second edge 334. The second thickness T2 is thicker than the first thickness T1. The ratio of the second thickness T2 to the first thickness T1 (T2 / T1) is, for example, 2 or more and 10 or less. The second wall 3372 is the heat storage part 3370. In the partition wall 337, for example, the first wall 3371 and the second wall 3372 are alternately arranged. That is, a unit of one first wall 3371 and one second wall 3372 may be repeated. On the other hand, a unit of two or more first walls 3371 and one second wall 3372 may be repeated. On the other hand, a unit of one first wall 3371 and two or more second walls 3372 may be repeated. The second thickness T2 is not limited to one, and may be two or more.

[0045] [Second Modified Example] Referring to FIG. 6, a second modified example of the ammonia decomposition facility 1 will be described. FIG. 6 is a cross-sectional view of the ammonia decomposition apparatus of the second modified example.

[0046] The ammonia decomposition part 33 includes a first part 339 and a second part 340. The first part 339 is formed of a first material having a first specific heat. The first part 339 has the same shape and the same material as the above-described partition wall 337. The second part 340 is formed of a second material and is the heat storage part 3370. The second material has the same specific heat as the first specific heat or a second specific heat higher than the first specific heat. Preferably, the second material has the same specific heat as the first specific heat. In this case, the second material may be the same as the first material. Examples of the second material include silicon carbide impregnated with metallic silicon. The second part 340 is filled in the whole of some of the plurality of flow paths 332. The second part 340 extends from the first edge 333 towards the second edge 334.

[0047] [Third Modified Example] Referring to FIG. 7, a third modified example of the ammonia decomposition facility 1 will be described. FIG. 7 is a perspective view of the ammonia decomposition part of the third modified example.

[0048] The partition 337 includes a plurality of third walls 3373 and a plurality of fourth walls 3374. The plurality of third walls 3373 are arranged radially with respect to the optical axis OA of the sunlight collected by the light collecting device 2. Specifically, the third walls 3373 are arranged such that the circumferential adjacent intervals gradually widen as they go outward from the optical axis OA of the sunlight. Also, the plurality of fourth walls 3374 are arranged concentrically with respect to the optical axis OA of the sunlight. The fourth wall 3374 connects adjacent third walls 3373. The fourth wall 3374 may cross adjacent third walls 3373.

[0049] [Fourth Modified Example] Referring to FIG. 8, a fourth modified example of the ammonia decomposition facility 1 will be described. FIG. 8 is an enlarged cross-sectional view of the ammonia decomposition section of the fourth modified example.

[0050] The ammonia decomposition section 33 has a foam structure 350. The foam structure 350 consists of pillars 351 connected to each other and a continuous internal space 352 formed between the pillars 351. A catalyst 338 (not shown in FIG. 8) may be arranged on the wall surface of the pillar 351 (see FIG. 4A). The catalyst 338 may be included in the pillar 351 (see FIG. 4B).

[0051] [Other Modified Examples] The starting point of the flow path 332 may be in the middle of the first edge 333 and the second edge 334. The ending point of the flow path 332 may be in the middle of the first edge 333 and the second edge 334.

[0052] It should be understood that the embodiments disclosed this time are illustrative in all respects and not restrictive in any way. The scope of the present disclosure is defined by the claims rather than the above description, and it is intended that all modifications within the meaning and scope equivalent to the claims be included.

[0053] 1 Ammonia decomposition equipment, 2 Light concentrator, 3 Ammonia decomposition unit, 4 Supply line, 5 Discharge line, 6 Detection device, 6A Illuminance meter, 6B Thermometer, 7 Control device, 21 Reflector, 22 Tracking device, 31 Container, 32 Window, 33 Ammonia decomposition section, 61 First illuminance meter, 62 Second illuminance meter, 63 Third illuminance meter, 65 First thermometer, 66 Second thermometer, 311 Supply path, 312 Discharge path, 331 Honeycomb structure, 332 Flow path, 333 First edge, 334 Second edge, 336 Outer wall, 337 Partition wall, 338 Catalyst, 339 First section, 340 Second section, 350 Foam structure, 351 Pillar, 352 Internal space, 3370 Heat storage section, 3371 First wall, 3372 Second wall, 3373 Third wall, 3374 Fourth wall, OA Optical axis, D1 First direction, FL Focal line, FP Focal point, T1 First thickness, T2 Second thickness.

Claims

1. An ammonia decomposition apparatus comprising: a light concentrator for collecting sunlight; an ammonia decomposition unit including an ammonia decomposition section that uses the sunlight collected by the light concentrator as a heat source to decompose ammonia and generate hydrogen; a detection device for detecting at least one physical quantity selected from the group consisting of the amount of sunlight irradiation and the temperature of the ammonia decomposition unit; and a control device for controlling the amount of ammonia supplied to the ammonia decomposition unit according to the physical quantity detected by the detection device.

2. The ammonia decomposition apparatus according to claim 1, wherein the light concentrating device includes a reflector that reflects sunlight and collects it in the ammonia decomposition section.

3. The ammonia decomposition apparatus according to claim 2, wherein the reflector is of the parabolic dish type having a focal point, or the parabolic trough type having a focal line.

4. The ammonia decomposition apparatus according to claim 2, wherein the reflector is of the parabolic dish type having a focal point.

5. The ammonia decomposition apparatus according to claim 1, wherein the ammonia decomposition unit includes a catalyst.

6. The ammonia decomposition apparatus according to claim 5, wherein the ammonia decomposition section has a plurality of channels through which ammonia can pass in a first direction, and has a honeycomb structure having a plurality of channels extending from a first edge of the ammonia decomposition section in the first direction toward a second edge located away from the first edge, the honeycomb structure includes an outer peripheral wall extending from the first edge to the second edge, and a partition wall extending from the first edge toward the second edge and supported by the outer peripheral wall, which partitions the internal space of the outer peripheral wall into the plurality of channels, and the catalyst is arranged on the wall surface of the partition wall.

7. The ammonia decomposition unit has a honeycomb structure having a plurality of channels through which ammonia can pass in a first direction, the channels extending from a first edge of the ammonia decomposition unit in the first direction toward a second edge located away from the first edge, the honeycomb structure includes an outer peripheral wall extending from the first edge to the second edge, and a partition wall extending from the first edge toward the second edge and supported by the outer peripheral wall, which partitions the internal space of the outer peripheral wall into the plurality of channels, the partition wall containing the catalyst, the ammonia decomposition apparatus according to claim 5.

8. The ammonia decomposition apparatus according to claim 6 or 7, wherein the partition wall includes a first wall having a first thickness and extending from the first edge toward the second edge, and a second wall having a second thickness greater than the first thickness and extending from the first edge toward the second edge.

9. The ammonia decomposition apparatus according to claim 6 or claim 7, wherein the ammonia decomposition section comprises a first portion formed from a first material having a first specific heat, and a second portion formed from a second material having the same specific heat as the first specific heat or a second specific heat higher than the first specific heat, and which is a heat storage section.

10. The ammonia decomposition apparatus according to claim 6 or 7, wherein the partition wall includes a plurality of third walls arranged radially with respect to the optical axis of sunlight collected by the light concentrator, and a plurality of fourth walls arranged concentrically with respect to the optical axis of sunlight.

11. The ammonia decomposition apparatus according to claim 5, wherein the ammonia decomposition section has a foam structure comprising pillars connected to each other and a continuous internal space formed by the pillars, ammonia is able to pass through the internal space, and the catalyst is arranged on the surface of the pillars.

12. The ammonia decomposition apparatus according to claim 5, wherein the ammonia decomposition section has a foam structure comprising pillars connected to each other and a continuous internal space formed by the pillars, ammonia is able to pass through the internal space, and the pillars contain the catalyst.

13. The ammonia decomposition apparatus according to claim 1, wherein the ammonia supplied to the ammonia decomposition apparatus is ammonia gas.

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