Ammonia decomposition device

Abstract

To make it possible to efficiently decompose ammonia into hydrogen and nitrogen in a decomposition vessel that houses catalyst which decomposes ammonia into hydrogen and nitrogen.SOLUTION: In an ammonia decomposition apparatus that decomposes ammonia NH3 into hydrogen H2 and nitrogen N2 in a decomposition vessel 10, a plurality of stages of catalyst layers 20 using catalyst 21, which decompose ammonia into hydrogen and nitrogen via a required interval in a flow direction of ammonia flowing in a decomposition vessel, are provided in the decomposition vessel, and a heater which heats the inside of the decomposition vessel is provided.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an ammonia decomposition apparatus that decomposes ammonia into hydrogen and nitrogen in a decomposition vessel. In particular, when using ammonia as a fuel, it is characterized in that ammonia can be efficiently decomposed into hydrogen and nitrogen in a decomposition vessel containing a catalyst for decomposing ammonia into hydrogen and nitrogen.

Background Art

[0002] In a combustion apparatus that mixes and burns fuel with combustion air, generally, a combustion apparatus using a hydrocarbon-based fuel as fuel is used.

[0003] However, when a hydrocarbon-based fuel is mixed with combustion air and burned in this combustion apparatus, there is a problem that a large amount of greenhouse gases such as carbon dioxide is generated.

[0004] Therefore, conventionally, ammonia has been used as fuel in a combustion apparatus.

[0005] However, ammonia has poor combustibility compared to hydrocarbon-based fuels and is difficult to completely burn. On the other hand, it is likely to misfire during combustion at low temperatures. If it is burned strongly, the flame temperature will increase, and the amount of NOx generated will increase.

[0006] Therefore, conventionally, as shown in Patent Document 1, ammonia is introduced into a reactor filled with a catalyst for decomposing ammonia into hydrogen and nitrogen, and before decomposing ammonia into hydrogen and nitrogen, a diluted gas heated to ammonia is mixed and diluted.

[0007] However, even when a diluted gas heated to ammonia is mixed and introduced into the reactor in this way, it has been difficult to sufficiently decompose ammonia into hydrogen and nitrogen.

[0008] Furthermore, Patent Document 2 shows a device in which a heating device is provided on the outer circumference of a catalyst housing that contains a catalyst for decomposing ammonia into hydrogen and nitrogen, and the catalyst housed in the catalyst housing is heated by the heating device when decomposing ammonia into hydrogen and nitrogen.

[0009] However, when the catalyst contained in the catalyst housing is heated by a heating device installed on the outer circumference of the catalyst housing, if the diameter of the catalyst housing is large, the catalyst in the central part of the catalyst housing is not sufficiently heated and activated, making it difficult to sufficiently decompose the ammonia passing through the catalyst housing into hydrogen and nitrogen.

[0010] Furthermore, Patent Documents 3 and 4 describe a method in which a catalyst containment is heated from the surroundings.

[0011] However, the devices shown in Patent Documents 3 and 4, like the one shown in Patent Document 2, had the problem that when the diameter of the catalyst housing increased, the catalyst in the central part of the catalyst housing was not sufficiently heated and therefore not activated. [Prior art documents] [Patent Documents]

[0012] [Patent Document 1] Japanese Patent Publication No. 2022-109042 [Patent Document 2] Japanese Patent Publication No. 2023-39681 [Patent Document 3] WO2011 / 052020 publication [Patent Document 4] Japanese Patent Publication No. 2012-57508 [Disclosure of the Invention] [Problems that the invention aims to solve]

[0013] The present invention aims to solve the aforementioned problems in an ammonia decomposition apparatus that decomposes ammonia into hydrogen and nitrogen in a decomposition vessel.

[0014] In other words, the object of the present invention is to enable the efficient decomposition of ammonia into hydrogen and nitrogen in a decomposition vessel containing a catalyst for decomposing ammonia into hydrogen and nitrogen, as described above, within the ammonia decomposition apparatus. [Means for solving the problem]

[0015] In the ammonia decomposition apparatus according to the present invention, in order to solve the above-mentioned problems, in an ammonia decomposition apparatus that decomposes ammonia into hydrogen and nitrogen in a decomposition vessel, multiple catalyst layers using catalysts that decompose ammonia into hydrogen and nitrogen are provided in the decomposition vessel at required intervals in the direction of ammonia flow in the decomposition vessel. In doing so, without using a catalyst that is heated by applying electricity, Inside the aforementioned decomposition container Each catalyst layer in A heating device for heating As an example, a heating device that heats each catalyst layer without supplying power to it. The decomposition container is provided on its outer circumference, and the heating device is provided on its outer circumference.

[0016] Thus, multiple catalyst layers containing catalysts that decompose ammonia into hydrogen and nitrogen are provided within the decomposition vessel at required intervals in the direction of ammonia flow within the vessel. In doing so, without using a catalyst that is heated by applying electricity, Inside the aforementioned decomposition container Each catalyst layer in A heating device for heating As an example, a heating device that heats each catalyst layer without supplying power to it. On the outer circumference of the decomposition container establish As a result, heat from the heating device installed on the outer periphery of the decomposition vessel is efficiently guided into the decomposition vessel, heating the catalyst layer. At the same time, heat from the heating device is also transmitted through the spaces between the catalyst layers to the center of each catalyst layer within the decomposition vessel, where the center of the catalyst layer is sufficiently heated, activating the catalyst, and allowing the ammonia flowing through the decomposition vessel to be efficiently decomposed into hydrogen and nitrogen through each catalyst layer.

[0017] Also, In the ammonia decomposition apparatus of the present invention, a heating device for heating the inside of the decomposition vessel as described above. Decomposition container is provided on the outer peripheral side , the above A heat insulator is provided on the outer peripheral side of the heating device.

[0018] Also, in the ammonia decomposition apparatus of the present invention, when providing a heating device for heating the inside of the decomposition container as described above, when providing a plurality of catalyst layers at required intervals in the flow direction of ammonia in the decomposition container, the catalyst layers can be provided at required intervals in the vertical direction in the decomposition container.

[0019] Further, in the ammonia decomposition apparatus of the present invention, when providing a plurality of catalyst layers at required intervals in the flow direction of ammonia in the decomposition container, holding means for holding the catalyst layers is provided in the decomposition container, and a space portion can be provided between the catalyst layers. By doing so, when the catalyst layer is heated by the heat from the heating device as described above, the heat from the heating device is also transmitted to the central portion of each catalyst layer in the decomposition container through the space portion between the catalyst layers, and the entire catalyst layer is sufficiently heated to activate the catalyst, so that ammonia flowing in the decomposition container is efficiently decomposed into hydrogen and nitrogen through each catalyst layer.

[0020] Also, in the ammonia decomposition apparatus of the present invention, when providing a plurality of catalyst layers at required intervals in the flow direction of ammonia in the decomposition container, a heat storage body having air permeability can be provided between the catalyst layers. By doing so, the heat storage body provided between the catalyst layers is heated and stores heat together with the catalyst layer by the heat from the heating device, and ammonia flowing in the decomposition container is heated by the heat stored in the heat storage body provided between the catalyst layers, so that ammonia flowing in the decomposition container is efficiently decomposed into hydrogen and nitrogen through each catalyst layer. In particular, when heat storage bodies having air permeability are provided on both sides in the flow direction of ammonia with respect to the catalyst layer, ammonia flowing in the decomposition container is heated by the heat stored in each heat storage body provided on both sides of the catalyst layer, so that ammonia flowing in the decomposition container is more efficiently decomposed into hydrogen and nitrogen.

Effect of the Invention

[0021] In the ammonia decomposition apparatus according to the present invention, a plurality of catalyst layers using a catalyst for decomposing ammonia into hydrogen and nitrogen are provided in the decomposition container at required intervals in the flow direction of ammonia flowing in the decomposition container as described above. In doing so, without using a catalyst that is heated by applying electricity, Inside the above-mentioned decomposition container Each catalyst layer in A heating device for heating As an example, a heating device that heats each catalyst layer without supplying power to it. is provided on the outer peripheral side of the decomposition container, and a heat insulator is provided on the outer peripheral side of the heating device. Therefore, the heat generated by the heating device provided on the outer peripheral side of the decomposition container is efficiently guided into the decomposition container to heat the catalyst layer, and the heat generated by the heating device is also transmitted to the central part of each catalyst layer in the decomposition container through the portion between the catalyst layers, so that the entire catalyst layer is sufficiently heated and the catalyst is activated.

[0022] As a result, in the ammonia decomposition apparatus according to the present invention, the ammonia introduced into the decomposition container is efficiently decomposed into hydrogen and nitrogen by the catalyst in each catalyst layer heated and activated up to the central part.

Brief Description of the Drawings

[0023] [Figure 1] It is a schematic cross-sectional explanatory view showing an ammonia decomposition apparatus according to Embodiment 1 of the present invention. [Figure 2] It is a schematic cross-sectional explanatory view showing Modification 1 of the ammonia decomposition apparatus according to Embodiment 1 above. [Figure 3] It is a schematic cross-sectional explanatory view showing an ammonia decomposition apparatus according to Embodiment 2 of the present invention. [Figure 4] It is a schematic cross-sectional explanatory view showing Modification 2 of the ammonia decomposition apparatus according to Embodiment 2 above.

Best Mode for Carrying Out the Invention

[0024] Hereinafter, the ammonia decomposition apparatus according to the embodiment of the present invention will be specifically described based on the accompanying drawings. Note that the ammonia decomposition apparatus according to the present invention is not limited to the one shown in the following embodiments, and can be appropriately modified and implemented within the scope not changing the gist of the invention.

[0025] (Embodiment 1) In the ammonia decomposition apparatus according to Embodiment 1, as shown in Figure 1, when decomposing ammonia NH3 into hydrogen H2 and nitrogen N2 in the decomposition container 10, an inlet 11 for introducing ammonia NH3 is provided at the bottom of the decomposition container 10, while an outlet 12 for taking out the hydrogen H2 and nitrogen N2 obtained from the decomposition of ammonia NH3 is provided at the top of the decomposition container 10. Ammonia NH3 is introduced into the decomposition container 10 through the inlet 11, the introduced ammonia NH3 is decomposed into hydrogen H2 and nitrogen N2 in the decomposition container 10, and the decomposed hydrogen H2 and nitrogen N2 are taken out from the outlet 12.

[0026] In this embodiment 1 of the ammonia decomposition apparatus, multiple catalyst layers 20 using a catalyst 21 that decomposes ammonia NH3 into hydrogen H2 and nitrogen N2 are provided in the decomposition container 10 at required intervals in the direction of ammonia NH3 flow. A pellet-shaped catalyst 21a is used as the catalyst 21, and a permeable holding member 31 such as a grating is provided in the decomposition container 10 at required intervals in the vertical direction, which is the direction of ammonia NH3 flow, to hold the pellet-shaped catalyst 21a so that it does not spill out. Multiple catalyst layers 20 are provided on each of these holding members 31 by stacking pellet-shaped catalyst 21a to an appropriate thickness (three layers in the example shown in the figure), and spaces 22 are provided between each catalyst layer 20.

[0027] Furthermore, in the ammonia decomposition apparatus according to this embodiment 1, a heating device 40 consisting of a heater for heating the inside of the decomposition vessel 10 is provided on the outer periphery of the decomposition vessel 10, and an insulating body 41 is provided on the outer periphery of the heating device 40, so that the heat from the heating device 40 is not radiated to the outside, and so that each catalyst layer 20 and each space 22 between the catalyst layers 20 provided inside the decomposition vessel 10 are efficiently heated.

[0028] In this embodiment 1 ammonia decomposition apparatus, the decomposition vessel 10 is heated by the heating device 40, and ammonia NH3 is introduced into the decomposition vessel 10 from the inlet 11 located at the bottom of the decomposition vessel 10. The introduced ammonia NH3 is then guided through the first catalyst layer 20a, the first space 22a, the second catalyst layer 20b, the second space 22b, and the third catalyst layer 20c in the decomposition vessel 10 in that order, and heated to decompose into hydrogen H2 and nitrogen N2, which are then removed from the outlet 12 located at the top of the decomposition vessel 10.

[0029] Here, as described above, when the heating device 40 provided on the outer circumference of the decomposition vessel 10 heats each catalyst layer 20 (20a to 20c) and each space 22 (22a, 22b) provided inside the decomposition vessel 10, the heat from the heating device 40 is transmitted to the central part of each catalyst layer 20 (20a to 20c) through each space 22 (22a, 22b), and the entire catalyst layer 20 (20a to 20c) is sufficiently heated so that the catalyst 21 is activated.

[0030] As a result, while heating the inside of the decomposition vessel 10 with the heating device 40 as described above, when ammonia NH3 introduced from the inlet 11 at the bottom of the decomposition vessel 10 is guided in the order of the first catalyst layer 20a, the first space 22a, the second catalyst layer 20b, the second space 22b, and the third catalyst layer 20c inside the decomposition vessel 10, the catalysts 21a, which are all sufficiently heated and activated, efficiently decompose the ammonia NH3 into hydrogen H2 and nitrogen N2, which can then be removed from the outlet 12.

[0031] In the ammonia decomposition apparatus according to Embodiment 1 described above, a pellet-shaped catalyst 21a is used for the catalyst 21 in the catalyst layer 20, but the catalyst 21 used is not limited to this type.

[0032] For example, in the modified example 1 shown in Figure 2, a honeycomb-shaped catalyst 21b that is permeable in the flow direction of ammonia NH3 is used as the catalyst 21, and a catalyst layer 20 molded into a predetermined shape is used. The catalyst layer 20 thus molded is held on a holding projection 32 that protrudes from the inner circumference of the decomposition vessel 10, and multiple stages (3 stages in the example shown in the figure) of the catalyst layer 20 are arranged in the vertical direction, which is the flow direction of ammonia NH3, with required intervals between them, and a space 22 is provided between each catalyst layer 20.

[0033] Here, in the modified example 1 shown in Figure 2, similar to the embodiment 1 shown in Figure 1, a heating device 40 consisting of a heater for heating the inside of the decomposition container 10 is provided on the outer circumference of the decomposition container 10, and an insulating body 41 is provided on the outer circumference of the heating device 40 to prevent heat from the heating device 40 from being radiated to the outside, thereby efficiently heating each catalyst layer 20 and each space 22 between the catalyst layers 20 provided inside the decomposition container 10.

[0034] Furthermore, in this modified example 1 ammonia decomposition apparatus, similar to that of Embodiment 1, the inside of the decomposition vessel 10 is heated by the heating device 40, and ammonia NH3 is introduced into the decomposition vessel 10 from the inlet 11 located at the bottom of the decomposition vessel 10. The introduced ammonia NH3 is then guided through the first catalyst layer 20a, the first space 22a, the second catalyst layer 20b, the second space 22b, and the third catalyst layer 20c in the decomposition vessel 10 in that order, and heated while being decomposed into hydrogen H2 and nitrogen N2, which are then removed from the outlet 12 located at the top of the decomposition vessel 10.

[0035] In this way, in the ammonia decomposition apparatus according to Modified Example 1, similar to that of Embodiment 1, ammonia NH3 introduced from the inlet 11 at the bottom of the decomposition vessel 10 is guided in the order of the first catalyst layer 20a, the first space 22a, the second catalyst layer 20b, the second space 22b, and the third catalyst layer 20c within the decomposition vessel 10, and the ammonia NH3 is efficiently decomposed into hydrogen H2 and nitrogen N2 by each catalyst 21b, which is sufficiently heated and activated, and can be removed from the outlet 12.

[0036] In the above-described embodiment 1 and modified example 1, the catalyst layer 20 is shown to be provided in three stages in the vertical direction, which is the flow direction of ammonia NH3, with required intervals between them. However, the number of stages of the catalyst layer 20 provided in the decomposition vessel 10 is not particularly limited, as long as a space 22 is formed between the catalyst layers 20, and it is possible to provide even more stages in the catalyst layer 20 if there are two or more stages.

[0037] Furthermore, in Embodiment 1 and Modified Example 1, an inlet 11 is provided at the bottom of the decomposition container 10, while an outlet 12 is provided at the top of the decomposition container 10. However, it is also possible to provide an inlet 11 at the top of the decomposition container 10, while providing an outlet 12 at the bottom of the decomposition container 10, and introducing ammonia NH3 into the decomposition container 10 from the inlet 11 at the top of the decomposition container 10, decomposing it into hydrogen H2 and nitrogen N2 within the decomposition container 10, and then removing it from the outlet 12 at the bottom of the decomposition container 10.

[0038] Furthermore, in the above-described embodiment 1 and modification 1, the inlet 11 and outlet 12 are provided at the top or bottom of the decomposition container 10, and multiple catalyst layers 20 are provided in the decomposition container 10 at required intervals in the vertical direction. However, the invention is not limited to this, and although not shown, the decomposition container 10 can also be placed horizontally, with the inlet 11 and outlet 12 provided on both sides of the decomposition container 10 in the horizontal direction, and multiple catalyst layers 20 can be provided in the decomposition container 10 at required intervals in the horizontal direction.

[0039] (Embodiment 2) In the ammonia decomposition apparatus according to Embodiment 2, as shown in Figure 3, when decomposing ammonia NH3 into hydrogen H2 and nitrogen N2 in the decomposition vessel 10, an inlet 11 for introducing ammonia NH3 is provided at the bottom of the decomposition vessel 10, while an outlet 12 for taking out the hydrogen H2 and nitrogen N2 obtained from the decomposition of ammonia NH3 is provided at the top of the decomposition vessel 10. Ammonia NH3 is introduced into the decomposition vessel 10 through the inlet 11, the introduced ammonia NH3 is decomposed into hydrogen H2 and nitrogen N2 in the decomposition vessel 10, and the decomposed hydrogen H2 and nitrogen N2 are taken out from the outlet 12.

[0040] In this embodiment 2 of the ammonia decomposition apparatus, a number of stages are alternately arranged in the vertical direction, which is the flow direction of ammonia NH3, within the decomposition container 10, consisting of a permeable heat storage body 23 and a catalyst layer 20 using a catalyst 21 that decomposes ammonia NH3 into hydrogen H2 and nitrogen N2.

[0041] Furthermore, in the ammonia decomposition apparatus according to this embodiment 2, as the heat storage body 23, a honeycomb-shaped heat storage material 24a that has permeability in the flow direction of ammonia NH3 is used as the heat storage material 24, and this honeycomb-shaped heat storage material 24a is molded into a predetermined shape, while in the catalyst layer 20, a pellet-shaped catalyst 21a is used as the catalyst 21, and the first heat storage body 23a molded from the honeycomb-shaped heat storage material 24 is placed in the lower part of the decomposition vessel 10 on the upstream side in the flow direction of ammonia NH3 introduced from the inlet 11, The first heat storage body 23a is supported on a holding projection 32 that protrudes from the inner circumference of the dissolution container 10. A first catalyst layer 20a is provided on the first heat storage body 23a, with pellet-shaped catalysts 21a stacked to an appropriate thickness. A second heat storage body 23b, formed from a honeycomb-shaped heat storage material 24, is provided on the first catalyst layer 20a. A second catalyst layer 20b is provided on the second heat storage body 23b, with pellet-shaped catalysts 21a stacked to an appropriate thickness. A third heat storage body 23c, formed from a honeycomb-shaped heat storage material 24, is provided on the second catalyst layer 20b.

[0042] In this case, the size of the honeycomb mesh of the honeycomb-shaped heat storage material 24 is set to be smaller than the minimum size of the pellet-shaped catalyst 21a so that the pellet-shaped catalyst 21a does not fall out through the holes in the mesh.

[0043] Furthermore, in the ammonia decomposition apparatus according to this second embodiment, a heating device 40 consisting of a heater for heating the inside of the decomposition vessel 10 is provided on the outer circumference of the decomposition vessel 10, and an insulating body 41 is provided on the outer circumference of the heating device 40 so that the heat from the heating device 40 is not radiated to the outside, thereby efficiently heating each of the heat storage bodies 23 (23a to 23c) and each of the catalyst layers 20 (20a, 20b) provided inside the decomposition vessel 10.

[0044] In this embodiment 2 of the ammonia decomposition apparatus, the decomposition vessel 10 is heated by the heating device 40, and ammonia NH3 is introduced into the decomposition vessel 10 from the inlet 11 located at the bottom of the decomposition vessel 10. The introduced ammonia NH3 is then guided through the first heat storage body 23a, the first catalyst layer 20a, the second heat storage body 23b, the second catalyst layer 20b, and the third heat storage body 23c in the decomposition vessel 10 in that order, and heated while being decomposed into hydrogen H2 and nitrogen N2, which are then removed from the outlet 12 located at the top of the decomposition vessel 10.

[0045] Here, as described above, when the heating device 40 provided on the outer circumference of the decomposition vessel 10 heats each heat storage body 23 (23a~23c) and each catalyst layer 20 (20a, 20b) provided inside the decomposition vessel 10, the ammonia NH3 introduced into the decomposition vessel 10 from the inlet 11 is heated by the heat stored in the first heat storage body 23a and guided to the first catalyst layer 20a, where the catalyst 21a in the heated first catalyst layer 20a converts hydrogen H2 and nitrogen Ammonia NH3 is decomposed into N2, and further heated by the heat stored in the second heat storage body 23b, and guided to the second catalyst layer 20b, where it is decomposed into hydrogen H2 and nitrogen N2 by the catalyst 21a in the heated second catalyst layer 20b. The hydrogen H2 and nitrogen N2 thus decomposed are then guided to the third heat storage body 23c, where they are heated by the heat stored in the third heat storage body 23c, and are then removed from the outlet 12.

[0046] Then, as described above, while the inside of the decomposition container 10 is heated by the heating device 40, the ammonia NH3 introduced from the inlet 11 at the bottom of the decomposition container 10 is guided in the order of the first heat storage body 23a, the first catalyst layer 20a, the second heat storage body 23b, the second catalyst layer 20b, and the third heat storage body 23c and heated, causing it to decompose into hydrogen H2 and nitrogen N2. By utilizing the heat storage bodies 23a, 23b, and 23c, a higher temperature is maintained than if only the space 22 were left empty. By sandwiching the catalyst layers 20a and 20b from above and below with the high-temperature heat storage bodies 23a, 23b, and 23c, the entire catalyst layers 20a and 20b are sufficiently heated, activating each catalyst 21a, and the ammonia NH3 is further efficiently decomposed into hydrogen H2 and nitrogen N2, which can then be removed from the outlet 12.

[0047] Furthermore, by heating the decomposed hydrogen (H2) and nitrogen (N2) in the third heat storage body 23c and removing them from the outlet 12, hydrogen (H2) can be extracted at a high temperature, making it easily usable as fuel.

[0048] In the ammonia decomposition apparatus according to Embodiment 2 described above, a honeycomb-shaped heat storage material 24a is used for the heat storage material 24 in the heat storage body 23, and a pellet-shaped catalyst 21a is used for the catalyst 21 in the catalyst layer 20. However, the heat storage material 24 in the heat storage body 23 and the catalyst 21 in the catalyst layer 20 used are not limited to these.

[0049] For example, in the modified example 2 shown in Figure 4, a ball-shaped heat storage material 24b is used in the heat storage material 24 of the heat storage body 23, and a permeable holding member 31 such as a grating is provided above the inlet 11 for introducing ammonia NH3 into the decomposition container 10 to hold the ball-shaped heat storage material 24b so that it does not spill out, and a first heat storage body 23a is provided on this holding member 31 by stacking ball-shaped heat storage material 24b to an appropriate thickness, and pellets are placed on top of this first heat storage body 23a. A first catalyst layer 20a is formed by stacking pellet-shaped catalysts 21a to an appropriate thickness, a second heat storage body 23b is formed on top of the first catalyst layer 20a by stacking ball-shaped heat storage materials 24b to an appropriate thickness, a second catalyst layer 20b is formed on top of the second heat storage body 23b by stacking pellet-shaped catalysts 21a to an appropriate thickness, and a third heat storage body 23c is formed on top of the second catalyst layer 20b by stacking ball-shaped heat storage materials 24b to an appropriate thickness.

[0050] In the modified example 2 shown in Figure 4, a heating device 40 consisting of a heater for heating the inside of the decomposition container 10 is provided on the outer circumference of the decomposition container 10, and an insulating body 41 is provided on the outer circumference of the heating device 40 to prevent heat from the heating device 40 from being radiated to the outside, thereby efficiently heating each of the heat storage bodies 23 (23a to 23c) and each of the catalyst layers 20 (20a, 20b) provided inside the decomposition container 10.

[0051] Furthermore, in this modified example 2 ammonia decomposition apparatus, similar to the ammonia decomposition apparatus in embodiment 2 described above, the heating device 40 heats the inside of the decomposition vessel 10, while ammonia NH3 is introduced into the decomposition vessel 10 from the inlet 11 located at the bottom of the decomposition vessel 10. The introduced ammonia NH3 is then guided through the first heat storage body 23a, the first catalyst layer 20a, the second heat storage body 23b, the second catalyst layer 20b, and the third heat storage body 23c in the decomposition vessel 10 in that order, and heated while being decomposed into hydrogen H2 and nitrogen N2, which are then removed from the outlet 12 located at the top of the decomposition vessel 10.

[0052] Here, as described above, when the heating device 40 provided on the outer circumference of the decomposition container 10 heats each heat storage body 23 (23a to 23c) and each catalyst layer 20 (20a, 20b) provided inside the decomposition container 10, the ammonia NH3 introduced from the inlet 11 is heated by the heat stored in the first heat storage body 23a and guided to the first catalyst layer 20a, where it is decomposed into hydrogen H2 and nitrogen N2. Furthermore, the ammonia NH3 is heated by the heat stored in the second heat storage body 23b and guided to the second catalyst layer 20b, where it is decomposed into hydrogen H2 and nitrogen N2. The hydrogen H2 and nitrogen N2 thus decomposed are then guided to the third heat storage body 23c, where they are heated by the heat stored in the third heat storage body 23c and are removed from the outlet 12.

[0053] Furthermore, in the ammonia decomposition apparatus according to this modified example 2, by using a ball-shaped heat storage material 24b, the heat storage material 24b also has horizontal permeability, so the heat from the heating device 40 is more easily transmitted to the center of each catalyst layer 20a, 20b than the honeycomb-shaped heat storage material 24a used in the ammonia decomposition apparatus according to the above embodiment 2. As a result, the ammonia NH3 introduced into the decomposition container 10 from the inlet 11 is more efficiently decomposed into hydrogen H2 and nitrogen N2 within the decomposition container 10 and can be removed from the outlet 12. In addition, the decomposed hydrogen H2 and nitrogen N2 are heated in the third heat storage body 23c and removed from the outlet 12, allowing hydrogen H2 to be extracted at a high temperature and easily used as fuel.

[0054] In the above-described embodiment 2 and modified example 2, the decomposition container 10 was shown to contain the three heat storage bodies 23 (23a to 23c) and two catalyst layers 20 (20a, 20b). However, the number of heat storage bodies 23 and catalyst layers 20 to be provided in the decomposition container 10 is not limited, and it is also possible to provide even more catalyst layers 20 and heat storage bodies 23 by alternating them.

[0055] Furthermore, in the above-described embodiment 2 and modified example 2, an inlet 11 is provided at the bottom of the decomposition container 10, while an outlet 12 is provided at the top of the decomposition container 10. However, it is also possible to provide an inlet 11 at the top of the decomposition container 10, while an outlet 12 is provided at the bottom of the decomposition container 10, and introduce ammonia NH3 into the decomposition container 10 from the inlet 11 at the top of the decomposition container 10, decompose it into hydrogen H2 and nitrogen N2 inside the decomposition container 10, and then remove it from the outlet 12 at the bottom of the decomposition container 10.

[0056] Furthermore, in the above-described embodiment 2 and modified example 2, the inlet 11 and outlet 12 are provided at the top or bottom of the decomposition container 10, and multiple catalyst layers 20 and heat storage bodies 23 are provided inside the decomposition container 10 in a vertical stacking manner. However, the invention is not limited to this, and although not shown, the decomposition container 10 can also be placed horizontally, with the inlet 11 and outlet 12 provided on both sides of the decomposition container 10 in the horizontal direction, and multiple catalyst layers 20 and heat storage bodies 23 can be provided inside the decomposition container 10 in a horizontal parallel arrangement. [Explanation of Symbols]

[0057] 10: Decomposition vessel 11: Inlet 12: Dispensing opening 20, 20a~20c: Catalyst layer 21, 21a, 21b: Catalyst 22, 22a, 22b: Space part 23, 23a~23c: Heat storage body 24, 24a, 24b: Heat storage material 31: Retaining member 32: Holding protrusion 40: Heating device 41: Insulator H2: Hydrogen N2: Nitrogen NH3: Ammonia

Claims

1. An ammonia decomposition apparatus for decomposing ammonia into hydrogen and nitrogen in a decomposition vessel, wherein multiple catalyst layers using catalysts that decompose ammonia into hydrogen and nitrogen are provided in the decomposition vessel at required intervals in the direction of ammonia flow in the decomposition vessel, and a heating device that heats each catalyst layer in the decomposition vessel without supplying power to each catalyst layer is provided on the outer periphery of the decomposition vessel, and an insulating body is provided on the outer periphery of the heating device, as a heating device that heats each catalyst layer without supplying power to each catalyst layer, without using a catalyst that is heated by applying an electric current.

2. An ammonia decomposition apparatus according to claim 1, characterized in that, when a plurality of catalyst layers are provided in the decomposition vessel at required intervals in the direction of ammonia flow, the catalyst layers are provided at required intervals in the vertical direction within the decomposition vessel.

3. An ammonia decomposition apparatus according to claim 1 or claim 2, characterized in that, when a plurality of catalyst layers are provided in the decomposition vessel at required intervals in the direction of ammonia flow, a holding means for holding the catalyst layers is provided in the decomposition vessel, and spaces are provided between the catalyst layers.

4. An ammonia decomposition apparatus according to claim 1 or claim 2, characterized in that, when a plurality of catalyst layers are provided in the decomposition vessel at required intervals in the direction of ammonia flow, a heat storage body with permeability is provided between the catalyst layers.

5. An ammonia decomposition apparatus according to claim 4, characterized in that a permeable heat storage body is provided on both sides in the direction of ammonia flow relative to the catalyst layer.

Images