Ammonia modification device

Abstract

To provide an ammonia modification device capable of suppressing nitriding corrosion and increasing the obtained hydrogen gas concentration.SOLUTION: An ammonia modification device 1 according to the present invention comprises an ammonia reformer 13 that generates a reformed gas containing hydrogen from ammonia by means of a modification catalyst 130 filled therein, wherein the modification catalyst 130 is a ruthenium-based catalyst, and the ammonia reformer 13 is filled with one or more types of heat conducting material 131 together with the modification catalyst 130.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an ammonia reformer, and more particularly to an ammonia reformer that can suppress nitriding corrosion and increase the concentration of hydrogen gas obtained. [Background technology]

[0002] It has been known that ammonia causes nitriding corrosion when it comes into contact with metals at high temperatures, and that the amount of nitriding corrosion increases particularly as the ammonia concentration in the source gas increases or the temperature increases.

[0003] In Patent Document 1, the heater section and catalyst member are arranged concentrically to eliminate temperature unevenness, but there is a problem in that high-concentration ammonia is heated by the heater section, which may cause nitriding corrosion.

[0004] Furthermore, in Patent Document 2, a dilution gas is mixed with the ammonia gas as a raw material to reduce the ammonia concentration and thereby suppress nitriding corrosion, but this results in a problem of a decrease in the concentration of the resulting hydrogen gas. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2023-22850 A [Patent Document 2] Patent No. 7319499 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide an ammonia reformer that can suppress nitriding corrosion and increase the concentration of the obtained hydrogen gas.

[0007] Further objects of the present invention will become apparent from the following description. [Means for solving the problem]

[0008] The above problems are solved by the following inventions.

[0009] 1. an ammonia reformer that generates a reformed gas containing hydrogen from ammonia using a reforming catalyst filled therein; the reforming catalyst is a ruthenium-based catalyst; The ammonia reformer is characterized in that the ammonia reformer is filled with one or more types of heat conductors together with the reforming catalyst. 2. The ammonia reformer is housed in a container, 2. The ammonia reformer according to item 1, further comprising a configuration for supplying a heat source capable of causing an endothermic reaction of ammonia to the reforming catalyst in the ammonia reformer during the process of introducing and discharging heat exchange gas into the container. 3. 2. The ammonia reformer according to item 1, wherein a filling ratio of the thermal conductor filled in the reforming catalyst is changed in the flow direction of the ammonia gas from upstream to downstream. 4. 4. The ammonia reformer according to any one of the above items 1, 2 and 3, wherein the thermal conductor is at least one selected from the group consisting of porous ceramics, ceramic particles and metal particles. 5. 4. The ammonia reformer according to any one of items 1, 2, and 3, wherein the thermal conductor is at least one selected from the group consisting of a nickel-based catalyst, a cobalt-based catalyst, an iron-based catalyst, a platinum-based catalyst, a magnesium-based catalyst, and a palladium-based catalyst. 6. a first ammonia reformer that generates a reformed gas containing hydrogen from ammonia using a reforming catalyst filled therein, the reforming catalyst being a ruthenium-based catalyst, and the first ammonia reformer is filled with one or more types of thermal conductors together with the reforming catalyst; a second ammonia reformer is provided downstream of the first ammonia reformer in a flow direction of the reformed gas; the second ammonia reformer is filled with at least one catalyst selected from a nickel-based catalyst, a cobalt-based catalyst, an iron-based catalyst, a platinum-based catalyst, a magnesium-based catalyst, and a palladium-based catalyst; 1. An ammonia reformer comprising: a heating unit that heats the catalyst in the second ammonia reformer. 7. the first ammonia reformer is housed in a container; 7. The ammonia reformer according to claim 6, further comprising a configuration for supplying a heat source capable of endothermic reaction of ammonia to the reforming catalyst in the first ammonia reformer during the process of introducing and discharging heat exchange gas into the container. 8. 8. The ammonia reformer according to item 7, wherein a heating section for heating the catalyst in the second ammonia reformer uses a heat source different from the heat source supplied to the first ammonia reformer. 9. 9. The ammonia reformer according to item 8, wherein the heat source of the heating section is an electric heater, a burner, waste heat from a fuel cell, or a combination of these. 10. 7. The ammonia reformer according to item 6, wherein the filling ratio of the thermal conductor filled in the reforming catalyst is changed in the flow direction of the ammonia gas from upstream to downstream. 11. 11. The ammonia reformer according to any one of items 6 to 10, wherein the thermal conductor packed in the first ammonia reformer is at least one selected from porous ceramics, ceramic particles, and metal particles. 12. 11. The ammonia reformer according to any one of items 6 to 10, wherein the thermal conductor packed in the first ammonia reformer is at least one selected from a nickel-based catalyst, a cobalt-based catalyst, an iron-based catalyst, a platinum-based catalyst, a magnesium-based catalyst, and a palladium-based catalyst. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide an ammonia reformer that can suppress nitriding corrosion and increase the concentration of the obtained hydrogen gas. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic cross-sectional view showing an example of an ammonia reformer of the present invention. [Figure 2] An explanatory diagram showing an example of an ammonia reformer [Figure 3] FIG. 1 is an explanatory diagram showing another example of an ammonia reformer. [Figure 4] FIG. 1 is a diagram illustrating an embodiment of an ammonia reformer employed in an embodiment. [Figure 5] Graph showing experimental results of the reference example [Figure 6] Graph showing experimental results of Example 1 [Figure 7] Graph showing experimental results of Example 2 [Figure 8] Graph showing experimental results of Example 3 [Figure 9] Graph showing experimental results of Example 4 [Figure 10] Graph showing experimental results of Example 5 [Figure 11] Graph showing experimental results comparing Example 6 and Reference Example 2 [Figure 12] Graph showing experimental results comparing Example 7, Example 6, and Reference Example 2 DETAILED DESCRIPTION OF THE INVENTION

[0012] Preferred embodiments of the present invention will now be described.

[0013] FIG. 1 is a schematic cross-sectional view showing one example of an ammonia reformer of the present invention, FIG. 2 is an explanatory view showing one example of an ammonia reformer, and FIG. 3 is an explanatory view showing another example of an ammonia reformer.

[0014] In FIG. 1, reference numeral 1 denotes an ammonia reformer, which is provided with an ammonia gas reservoir 10 at one end and a reformed gas reservoir 11 at the other end, although this is not particularly limited. Between the ammonia gas storage section 10 and the reformed gas storage section 11, a cylindrical container is formed.

[0015] The ammonia gas storage section 10 is provided with an inlet 100 for ammonia gas, which is a reforming raw material, and the reformed gas storage section 11 is provided with an outlet 110 for the reformed gas.

[0016] Ammonia gas is preferably used as the raw material for generating the reformed gas. The method for obtaining the raw material ammonia gas is not particularly limited, and liquid ammonia can be gasified using an evaporator (not shown) to generate ammonia gas, which can be used as the raw material.

[0017] Ammonia gas is decomposed into nitrogen gas and hydrogen gas through the reaction 2NH3 → N2 + 3H2 to produce reformed gas. The reformed gas may also contain a small amount of unreacted ammonia gas.

[0018] In the present invention, the term "reformed gas" refers to, for example, when ammonia is used as engine fuel, the use as a fuel is in the same category, but reforming aims to improve the quality of the fuel, and the resulting gas is called reformed gas. When the components of the reformed gas are nitrogen gas, hydrogen gas, and a small amount of unreacted ammonia gas as described above, the small amount of unreacted ammonia gas is not reformed, and nitrogen gas is an inert component and not suitable as a fuel, so the qualitative improvement is in the point that hydrogen gas is produced.

[0019] Ammonia is one of the hydrogen carriers, and the present invention aims to use ammonia by reforming it into hydrogen. The reaction of reforming ammonia into hydrogen is an endothermic reaction, and generally proceeds at high temperatures by contacting the ammonia with a catalyst.

[0020] In the present invention, in order to utilize a heat source such as high-temperature exhaust gas for the reforming reaction, a heat exchange type reformer shown in FIG. 1, 2 or 3 can be preferably used. For separating hydrogen gas and nitrogen gas, zeolite or a hydrogen separation membrane can be used as needed.

[0021] 1, a cylindrical container 12 between an ammonia gas storage section 10 and a reformed gas storage section 11 is provided with a heat exchange gas inlet 120, and an outlet 121 is provided on the opposite side of the inlet 120. This embodiment supplies a heat source necessary for the endothermic reaction by such heat exchange gas, and therefore, as mentioned above, is called a heat exchange type reformer.

[0022] A cylindrical ammonia reformer 13 is provided inside the cylindrical container 12. The example shown in Fig. 1 is an embodiment in which one ammonia reformer 13 is provided, but two or more ammonia reformers 13 may be provided depending on the production target of the reformed gas, etc.

[0023] As shown in FIG. 2, the ammonia reformer 13 is filled with a reforming catalyst 130 therein, and the reforming catalyst 130 acts to produce a reformed gas containing hydrogen from ammonia.

[0024] The side portion 13a of the ammonia reformer 13 is preferably formed of a plate-like metal having excellent thermal conductivity. When the heat exchange gas contains a corrosive gas, it is preferable to use a corrosion-resistant metal as the metal material.

[0025] A ruthenium-based catalyst is used as the reforming catalyst 130. The ruthenium-based catalyst may be a Ru (ruthenium) catalyst alone, but may also be mixed with other metal catalysts within a range that achieves the object of the present invention.

[0026] 2, the ammonia reformer 13 contains a reforming catalyst 130 mixed with a thermal conductor 131. In this embodiment, the ammonia reformer 13 is preferably filled with one or more types of thermal conductors 131 together with the reforming catalyst 130.

[0027] The ruthenium-based catalyst used in the reforming catalyst 130 promotes the reaction at low temperatures below 500°C, but the endothermic reaction causes the temperature of the ammonia gas to drop and the reaction to stop, so a higher temperature heat exchange gas is required. By filling one or more types of heat conductors 131 together with the ruthenium-based catalyst 130, the amount of reforming reaction can be limited while operating at low temperatures, and the amount of heat absorbed can be reduced, which has the effect of eliminating the need for high-temperature heat exchange gas.

[0028] When the thermal conductor 131 is intended for thermal conduction, it is preferable that it is at least one selected from porous ceramics, ceramic particles, metal particles, and the like.

[0029] Porous ceramics include porous alumina (Al2O3:3.5) and porous zirconia (ZrO2:0.8). Ceramic particles include aluminum nitride (AlN:150), silicon carbide (SiC:60), alumina (Al2O3:32), sapphire (42), zirconia (ZrO2:3), and silicon nitride (Si3N4:20). Metal particles (metals) include nickel (Ni:85) and SUS304 (16). Note that the values ​​in parentheses indicate thermal conductivity at 20°C [W / m K].

[0030] In addition, in the present invention, when both the functions of heat conduction and reforming catalytic action are required, it is preferable to use at least one selected from nickel-based catalysts, cobalt-based catalysts, iron-based catalysts, platinum-based catalysts, magnesium-based catalysts, and palladium-based catalysts as the heat conductor.

[0031] In this embodiment, it is preferable to change the filling (mixing) ratio of the thermal conductor 131 mixed into the reforming catalyst 130 in the flow direction of the ammonia gas from upstream (left side of the drawing) to downstream (right side of the drawing), as shown in FIG. As a mode of change, for example, a mode in which the mixing ratio of the reforming catalyst 130 is higher on the downstream side of the ammonia gas than on the upstream side, that is, a mode in which the mixing density is higher, is preferable.

[0032] According to these embodiments, the mixture ratio or heat exchange surface area of ​​the reforming catalyst 130 is increased in the direction of ammonia gas flow, and the amount of heat absorption and the amount of heat exchange are balanced, thereby preventing a decrease in the ammonia gas temperature.

[0033] In FIG. 3, 14 denotes a first ammonia reformer that produces a reformed gas containing hydrogen from ammonia using a reforming catalyst 130 packed inside.

[0034] A second ammonia reformer 15 is disposed downstream of the first ammonia reformer 14 and produces a reformed gas containing hydrogen from ammonia by means of a reforming catalyst (not shown) packed therein. Reference numeral 16 denotes a heating section that generates heat when electricity is applied, and it is preferable to use, for example, an electric heater, a burner, waste heat from a fuel cell, or a combination of these heat sources. As in the embodiment shown in FIG. 2, a ruthenium-based catalyst is used as the reforming catalyst packed in the first ammonia reformer 14 and the second ammonia reformer 15.

[0035] According to this embodiment, the first ammonia reformer 14 contains a reforming catalyst 130 mixed with a thermal conductor 131, and the heating unit 16 heats the second ammonia reformer 15.

[0036] The reformed gas that has passed through the first ammonia reformer 14 may contain undecomposed ammonia in addition to hydrogen and nitrogen, which are decomposition products. Since the ammonia contained in the reformed gas is of low concentration, there is an effect of suppressing the risk of nitriding corrosion even when the reformed gas is heated by a heater, which is the heating unit 16, in the second ammonia reformer 15.

[0037] In this embodiment as well, it is preferable to vary the mixing ratio of the heat conductor 131 that is filled and mixed together with the reforming catalyst 130 in the direction of ammonia gas flow from upstream to downstream.

[0038] Although the preferred embodiments of the present invention have been described above, similar effects can be achieved by using a low-loading ruthenium-based catalyst, and the use of multiple catalysts with different loadings to create a loading gradient is not excluded.

[0039] Furthermore, when diluting with a thermal conductor, the use of a high-loading ruthenium-based catalyst is expected to have the effect of increasing the efficiency of precious metal recovery.

[0040] Furthermore, costs can be reduced by reducing the amount of expensive Ru catalyst used while maintaining the same reforming rate.

[0041] Furthermore, ruthenium-based catalysts sinter at high temperatures, reducing their catalytic activity, but operating at low temperatures can reduce the risk of sintering.

[0042] When the device of the present invention is installed on a ship, nitriding corrosion can be suppressed, which has the effect or benefit of extending the life of the vessel and reducing the frequency of maintenance and replacement.

[0043] In addition, since the required reforming temperature is low, when using the ship's main engine exhaust gas (350°C to 450°C) or auxiliary engine exhaust gas (400°C to 550°C) as heat exchange gas, it is possible to eliminate or minimize the need for a heating device. [Example]

[0044] Examples of the present invention will be described below, but the present invention is not limited to these examples.

[0045] (Reference example) As shown in the reference example of FIG. 4(A), an ammonia reformer (300 mm) was used, and only Ru pellets were filled as a ruthenium (Ru)-based catalyst (hereinafter abbreviated as Ru catalyst as necessary), and no thermal conductor was used. Ammonia gas was supplied to the above-mentioned ammonia reformer at a fixed space velocity (SV) of 1500 (1 / h) (relative to the amount of Ru catalyst) to carry out a reforming experiment. The experimental results are shown in Figure 5(A) and Figure 5(B).

[0046] The graph in FIG. 5(A) shows the reforming rate of NH3 at each temperature at the reformed gas outlet when the reforming temperature (heat exchange gas temperature) is changed to 450°C, 500°C, 550°C, and 600°C. The graph in FIG. 5(B) shows the relationship between catalyst length (mm) and gas temperature (° C.). The above experiment shows that the reforming rate does not reach 90% at 500°C.

[0047] Example 1 As shown in Example 1 in Figure 4(B), an ammonia reformer (550 mm) was filled with a Ru catalyst and a thermal conductor. The Ru catalyst layers were arranged so that they sandwiched a thermal conductor layer. Specifically, the ammonia reformer was arranged in the following order: Ru catalyst layer / thermal conductor layer / Ru catalyst layer / thermal conductor layer / Ru catalyst layer / thermal conductor layer / Ru catalyst layer / thermal conductor layer / Ru catalyst layer / thermal conductor layer / Ru catalyst layer / thermal conductor layer / Ru catalyst layer. The Ru catalyst layer was made of Ru catalyst, and the thermal conductor layer was made of porous alumina catalyst without catalyst support. Ammonia gas was supplied to the ammonia reformer at a fixed space velocity (SV) of 1500 (1 / h) (relative to the amount of Ru catalyst) to carry out a reforming experiment. The experimental results are shown in Figure 6.

[0048] The graph in Figure 6(A) shows the reforming rate of NH3 at each temperature at the outlet of the reformed gas when the reforming temperature is changed to 450°C, 500°C, 550°C, and 600°C, in comparison with the reference example. The graph in FIG. 6(B) shows the relationship between catalyst length (mm) and gas temperature (° C.).

[0049] According to the above experiment, the reforming rate improves to 90% at 500°C, and the required heat exchange gas temperature can be lowered by about 25°C. Compared to the reference example, it can be seen that the amount of heat absorption increases and the drop in gas temperature is mitigated.

[0050] Example 2 As shown in Example 2 in Figure 4(C), one ammonia reformer was used and filled with a Ru reforming catalyst mixed with a thermal conductor at a ratio of 50%. The thermal conductor was porous alumina without catalyst support. Ammonia gas was supplied to the ammonia reformer at a fixed space velocity (SV) of 1500 (1 / h) (relative to the amount of Ru catalyst) to carry out a reforming experiment.

[0051] The graph in Figure 7(A) shows the reforming rate of NH3 at each temperature at the reformed gas outlet when the reforming temperature is changed to 450°C, 500°C, 550°C, and 600°C, in comparison with the reference example. The graph in FIG. 7(B) shows the relationship between catalyst length (mm) and gas temperature (° C.). According to the above experiment, it is found that, similar to the alternate lamination in Example 1, the reforming rate reaches 90% at 500°C.

[0052] Example 3 As shown in Example 3 in Figure 4(D), the catalyst layer of the ammonia reformer was divided into three layers, and the mixing ratio of the thermal conductor to the catalyst in each layer was changed so that the mixing ratio gradually increased: 40% in the first layer, 50% in the second layer, and 60% in the third layer. Ammonia gas was supplied to the ammonia reformer at a fixed space velocity (SV) of 1500 (1 / h) (relative to the amount of Ru catalyst) to carry out a reforming experiment.

[0053] 8(A) shows the reforming rate of NH3 at each temperature of the reformed gas outlet when the reforming temperature was changed to 498° C., 500° C., 502° C., and 504° C. The experiment was conducted in comparison with Example 2. 8(B) is a graph showing the relationship between catalyst length (mm) and gas temperature (° C.). The above experiment shows that the temperature of the heat exchange gas can be further lowered, which is necessary in Example 2. It is also clear that by adjusting the mixing ratio, the amount of heat absorbed and the temperature distribution can be adjusted, and the reforming performance can be improved.

[0054] Example 4 As shown in Example 4 in FIG. 4(E), a Ru catalyst and a thermal conductor were mixed and packed into one ammonia reformer. A nickel-based catalyst (hereinafter, abbreviated as Ni catalyst as necessary) was used as a thermal conductor, and was mixed at 50% with the Ru catalyst at a ratio of 1:1. Ammonia gas was supplied to the ammonia reformer at a fixed space velocity (SV) of 1500 (1 / h) (relative to the amount of Ru catalyst) to carry out a reforming experiment.

[0055] The graph in Figure 9(A) shows the reforming rate of NH3 at each temperature at the outlet of the reformed gas when the reforming temperature is changed to 450°C, 500°C, 550°C, and 600°C, in comparison with the reference example. 9(B) is a graph showing the relationship between catalyst length (mm) and gas temperature (° C.) The experiment was conducted in comparison with the reference example. The above experiment shows that the required heat exchange gas temperature can be lowered by about 40°C. It is also apparent that the amount of heat absorbed increases and the decrease in gas temperature is mitigated compared to the reference example.

[0056] Example 5 As shown in Example 5 in Figure 4(F), the catalyst layer of the ammonia reformer was divided into three layers, and the mixing ratio of the nickel-based catalyst to the catalyst in each layer was changed to increase from 10%, 50%, to 90%. Ammonia gas was supplied to the ammonia reformer at a fixed space velocity (SV) of 1500 (1 / h) (relative to the amount of Ru catalyst) to carry out a reforming experiment.

[0057] 10(A) shows the reforming rate of NH3 at each temperature of the reformed gas outlet when the reforming temperature was changed to 478° C., 480° C., 482° C., and 484° C. The experiment was conducted in comparison with Example 4. 10(B) is a graph showing the relationship between catalyst length (mm) and gas temperature (° C.). The above experiment shows that the necessary temperature of the heat exchange gas can be further reduced from Example 4. It is also clear that by adjusting the mixing ratio, the amount of heat absorbed and the temperature distribution can be adjusted, and the reforming performance can be improved.

[0058] Example 6 A reforming experiment was carried out in the same manner as in Example 2, except that the space velocity (SV) when ammonia gas was supplied to the ammonia reformer was fixed at 2900 (1 / h) (relative to the amount of Ru catalyst).

[0059] (Reference example 2) A reforming experiment was carried out in the same manner as in the Reference Example, except that the space velocity (SV) was fixed at 2900 (1 / h) (relative to the amount of Ru catalyst).

[0060] 11 shows the reforming rate of NH3 at each temperature at the reformed gas outlet when the reforming temperature is changed in Example 6 and Reference Example 2. Example 6 and Reference Example 2 are shown for comparison. According to the above experiment, compared with Reference Example 2, Example 6 showed a slight improvement in the reforming performance.

[0061] Example 7 A reforming experiment was carried out in the same manner as in Example 6, except that the catalyst-free porous alumina used in Example 6 was replaced with nickel metal particles as the heat conductor.

[0062] 12 shows the reforming rate of NH3 at each temperature at the reformed gas outlet when the reforming temperature is changed in Examples 6, 7, and Reference Example 2. Examples 6, 7, and Reference Example 2 are shown for comparison. According to the above experiment, in Example 7, the required heat exchange gas temperature could be reduced by 25°C compared to Example 6, and furthermore, the higher the thermal conductivity of the heat conductor, the more improved the reforming performance was observed. [Explanation of symbols]

[0063] 1. Ammonia reformer 10 Ammonia gas storage section 100 Ammonia gas inlet 11 Reformed gas storage section 110 Reformed gas outlet 12 Cylindrical container 120 Heat exchange gas inlet 121 Heat exchange gas outlet 13 Ammonia reformer 13a Side 130 Reforming catalyst 131 Thermal Conductors 14 First ammonia reformer 15 Second ammonia reformer 16 Heating section

Claims

1. an ammonia reformer that generates a reformed gas containing hydrogen from ammonia using a reforming catalyst filled therein; the reforming catalyst is a ruthenium-based catalyst; The ammonia reformer is characterized in that the ammonia reformer is filled with one or more types of heat conductors together with the reforming catalyst.

2. The ammonia reformer is housed in a container, 2. The ammonia reformer according to claim 1, further comprising a configuration for supplying a heat source capable of causing an endothermic reaction of ammonia to the reforming catalyst in the ammonia reformer during the process of introducing and discharging a heat exchange gas into the container.

3. 2. The ammonia reformer according to claim 1, wherein a filling ratio of said thermal conductor filled in said reforming catalyst is changed in a flow direction of ammonia gas from upstream to downstream.

4. 4. The ammonia reformer according to claim 1, wherein the heat conductor is at least one selected from the group consisting of porous ceramics, ceramic particles, and metal particles.

5. 4. The ammonia reformer according to claim 1, 2 or 3, wherein the thermal conductor is at least one selected from the group consisting of a nickel-based catalyst, a cobalt-based catalyst, an iron-based catalyst, a platinum-based catalyst, a magnesium-based catalyst and a palladium-based catalyst.

6. a first ammonia reformer that generates a reformed gas containing hydrogen from ammonia using a reforming catalyst filled therein, the reforming catalyst being a ruthenium-based catalyst, and the first ammonia reformer is filled with one or more types of heat conductors together with the reforming catalyst; a second ammonia reformer is provided downstream of the first ammonia reformer in a flow direction of the reformed gas; the second ammonia reformer is filled with at least one catalyst selected from a nickel-based catalyst, a cobalt-based catalyst, an iron-based catalyst, a platinum-based catalyst, a magnesium-based catalyst, and a palladium-based catalyst; an ammonia reformer comprising: a heating unit for heating the catalyst in the second ammonia reformer;

7. the first ammonia reformer is housed in a container; 7. The ammonia reformer according to claim 6, further comprising a configuration for supplying a heat source capable of causing an endothermic reaction of ammonia to the reforming catalyst in the first ammonia reformer during a process of introducing and discharging a heat exchange gas into the container.

8. 8. The ammonia reformer according to claim 7, wherein a heating section for heating the catalyst in the second ammonia reformer uses a heat source different from the heat source supplied to the first ammonia reformer.

9. 9. The ammonia reformer according to claim 8, wherein the heat source of the heating unit is an electric heater, a burner, waste heat from a fuel cell, or a combination of these heat sources.

10. 7. The ammonia reformer according to claim 6, wherein a filling ratio of said thermal conductor filled in said reforming catalyst is changed in a flow direction of ammonia gas from upstream to downstream.

11. The ammonia reformer according to any one of claims 6 to 10, characterized in that the thermal conductor filled in the first ammonia reformer is at least one selected from porous ceramics, ceramic particles, and metal particles.

12. 11. The ammonia reformer according to any one of claims 6 to 10, wherein the thermal conductor filled in the first ammonia reformer is at least one selected from a nickel-based catalyst, a cobalt-based catalyst, an iron-based catalyst, a platinum-based catalyst, a magnesium-based catalyst, and a palladium-based catalyst.

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