Ammonia gas reformer

Abstract

To provide an ammonia gas reformer capable of sufficiently obtaining heat necessary for reforming ammonia gas and preventing an excessive temperature rise.SOLUTION: An ammonia gas reformer 11 comprises: a mixed gas channel 17 for ammonia gas and air to flow therethrough; an ATR catalyst unit 18 provided in the mixed gas channel 17 and including a combustion catalyst for combusting ammonia gas and a reforming catalyst for reforming ammonia gas; and a combustion catalyst unit 16 disposed upstream relative to the ATR catalyst unit 18 in the mixed gas channel 17 to always heat ammonia gas.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an ammonia gas reformer. [Background technology]

[0002] As a conventional technique related to an ammonia gas reformer, for example, the ammonia gas decomposition method described in Patent Document 1 is known. In the ammonia gas decomposition method described in Patent Document 1, ammonia and an oxygen-containing gas are supplied and a reforming reaction is carried out to produce nitrogen and hydrogen. In the ammonia gas decomposition method described in Patent Document 1, an autothermal reforming (ATR) reaction is carried out. Because ammonia and an oxygen-containing gas pass through a reactor carrying an ammonia reforming catalyst from the inlet to the outlet, a combustion reaction is likely to occur near the inlet of the reactor. As a result, the temperature near the outlet of the reactor is about 200°C lower than near the inlet.

[0003] Furthermore, Patent Document 2 describes a hydrogen production catalyst in which an ammonia combustion catalyst component is arranged in the front stage and an ammonia reforming catalyst component is arranged in the rear stage. The hydrogen production catalyst in Patent Document 2 uses the heat generated in the ammonia combustion reaction in the front stage for the ammonia reforming reaction in the rear stage, eliminating the need for excessive heating from outside the reactor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-214225 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-240646 Summary of the Invention [Problem to be solved by the invention]

[0005] However, since the temperature near the outlet of the reactor described in Patent Document 1 is about 200°C lower than near the inlet, the heat required for reforming is not obtained sufficiently near the outlet of the reactor, resulting in a problem of reduced reforming efficiency. On the other hand, while it is conceivable to increase the temperature of the combustion reaction in order to improve reforming efficiency, this could result in damage and deterioration of the reactor. In the technology described in Patent Document 2, an ammonia combustion catalyst component is placed in the front stage and an ammonia reforming catalyst component in the rear stage. As a result, the heat required for the ammonia reforming reaction is supplied from the front stage. As a result, no heat is generated in the rear stage, so the heat required for reforming is not obtained in sufficient quantity, resulting in a sudden drop in temperature and a deterioration in reforming efficiency. On the other hand, while it is possible to increase the temperature of the combustion reaction in the front stage in order to improve reforming efficiency, this could result in damage or deterioration of the reactor.

[0006] The present invention has been made in consideration of the above problems, and an object of the present invention is to provide an ammonia gas reforming apparatus that can obtain a sufficient amount of heat required for reforming ammonia gas while preventing an excessive temperature rise. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides an ammonia gas reforming apparatus having a gas flow path section through which ammonia gas flows, and an ATR catalyst section that is provided in the gas flow path section and includes a combustion catalyst for burning ammonia gas and a reforming catalyst for reforming the ammonia gas, the apparatus further comprising: a heating section that is provided upstream of the ATR catalyst section in the gas flow path section and constantly heats ammonia gas; an upstream air supply section that supplies air to a section in the gas flow path section between the heating section and the ATR catalyst section; the heating section has a combustion catalyst; and the heating section and the ATR catalyst are separate bodies and connected to each other by the gas flow path section. stomach It is characterized by the following.

[0008] In such an ammonia gas reformer, the air required for the combustion reaction in the ATR catalyst section is supplied together with the ammonia gas from the gas flow passage section through which the ammonia gas flows. Furthermore, the ammonia gas and a portion of the air are heated in the heating section, so the ammonia gas and air are constantly heated by this combustion heat. Therefore, the heat required for the reforming reaction in the ATR catalyst section is supplied via the ammonia gas and air heated in the heating section provided upstream. As a result, the ATR catalyst section can obtain sufficient heat required for reforming the ammonia gas. Furthermore, combustion in the heating section prevents excessive temperature rise in the downstream ATR catalyst section. Furthermore, in this configuration, air can be supplied to the ATR catalyst section, which suppresses a decrease in the combustion efficiency of ammonia gas due to a lack of oxygen in the ATR catalyst section, and improves the reforming efficiency of ammonia gas.

[0009] Also, The present invention provides an ammonia gas reforming device having a gas flow path section through which ammonia gas flows, and an ATR catalyst section that is provided in the gas flow path section and includes a combustion catalyst for burning ammonia gas and a reforming catalyst for reforming the ammonia gas. The device further includes a heating section that is provided upstream of the ATR catalyst section in the gas flow path section and constantly heats ammonia gas, the ATR catalyst section having an upstream catalyst section located upstream and a downstream catalyst section that is located downstream of the upstream catalyst section and has a higher combustion reaction rate than the upstream catalyst section, the heating section having a combustion catalyst, and the heating section and the ATR catalyst are separate entities and connected to each other via the gas flow path section.

[0011] Furthermore, in the above-described ammonia gas reforming apparatus, the ATR catalytic section may be configured to include an upstream catalytic section located on the upstream side, and a downstream catalytic section located downstream of the upstream catalytic section and having a higher combustion reaction rate than the upstream catalytic section. In such a configuration, the combustion reaction rate in the downstream catalytic section is higher than that in the upstream catalytic section, so that the heat required for reforming ammonia gas can be easily obtained in the downstream catalytic section of the ATR catalytic section, thereby improving the reforming efficiency of ammonia gas.

[0012] The above ammonia gas reforming device may also be configured to include a downstream air supply section that supplies air between the upstream catalytic section and the downstream catalytic section. In this configuration, air can be supplied to the downstream catalytic section, which prevents a decrease in the combustion efficiency of ammonia gas due to a lack of oxygen in the downstream catalytic section, and improves the reforming efficiency of ammonia gas.

[0013] In the above ammonia gas reforming device, the ATR catalyst section may be configured so that the reforming reaction rate is higher than the combustion reaction rate. In this configuration, an excessive temperature rise in the ATR catalyst section due to the combustion reaction of ammonia gas can be prevented, and damage and deterioration of the ATR catalyst section can be prevented.

[0014] In the above ammonia gas reforming apparatus, the upstream air supply section may have an air supply amount adjustment mechanism that adjusts the amount of air supplied. In this configuration, the air supply amount adjusting mechanism adjusts the amount of air supplied by the upstream air supply unit, and the ATR catalyst unit can supply just the right amount of oxygen necessary for the ammonia gas combustion reaction. This prevents damage and deterioration of the ATR catalyst unit due to excessive temperature rise and a decrease in the ammonia gas reforming efficiency due to insufficient heat. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide an ammonia gas reforming apparatus that can obtain sufficient heat required for reforming ammonia gas and prevent an excessive temperature rise. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic diagram showing the configuration of an ammonia gas reforming apparatus according to a reference example of the present invention. [Figure 2] Graph (a) shows the change in temperature from the inlet side to the outlet side of the ammonia gas reforming device according to the reference example, graph (b) shows the change in temperature from the inlet side to the outlet side of the ammonia gas reforming device according to the comparative example 1, and graph (c) shows the change in temperature from the inlet side to the outlet side of the ammonia gas reforming device according to the comparative example 2. [Figure 3] FIG. 10 is a schematic diagram showing the configuration of an ammonia gas reforming apparatus according to a modified example of the reference example. [Figure 4] FIG. 1(a) is a schematic diagram showing the configuration of an ammonia gas reforming apparatus according to a first embodiment, and FIG. 1(b) is a graph showing the change in temperature from the inlet side to the outlet side of the ammonia gas reforming apparatus according to the first embodiment. [Figure 5]FIG. 1(a) is a schematic diagram showing the configuration of an ammonia gas reforming apparatus according to a second embodiment, and FIG. 1(b) is a graph showing the change in temperature from the inlet side to the outlet side of the ammonia gas reforming apparatus according to the second embodiment. [Figure 6] FIG. 10(a) is a schematic diagram showing the configuration of an ammonia gas reforming apparatus according to a third embodiment, and FIG. 10(b) is a graph showing the change in temperature from the inlet side to the outlet side of the ammonia gas reforming apparatus according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] ( Reference example ) Hereinafter, the present invention Reference example This will be described with reference to the drawings.

[0018] As shown in Figure 1, Reference example The ammonia gas reformer 11 has an ammonia gas supply unit 12, an air supply unit 14, a combustion catalyst unit 16, and an ATR catalyst unit 18. The air supply unit 14 is connected to the combustion catalyst unit 16 via an air flow path 15. The ammonia gas supply unit 12 is connected to the air flow path 15 via an ammonia gas flow path 13. Therefore, the ammonia gas supply unit 12 is connected to the combustion catalyst unit 16 via the ammonia gas flow path 13 and the air flow path 15. The combustion catalyst unit 16 and the ATR catalyst unit 18 are connected via a mixed gas flow path 17.

[0019] The ammonia gas supply unit 12 has a function of supplying ammonia gas, which is a fuel gas, to the combustion catalyst unit 16. The ammonia gas supply unit 12 has an ammonia tank (not shown) that stores ammonia in a liquid state, and a vaporizer (not shown) that vaporizes the liquid ammonia to produce ammonia gas. The ammonia gas produced in the ammonia gas supply unit 12 is supplied to the combustion catalyst unit 16 through an ammonia gas flow path 13. The ammonia gas flow path 13 is a flow path for distributing ammonia gas from the ammonia gas supply unit 12 to the combustion catalyst unit 16, and is a part of the gas flow path unit. One end of the ammonia gas flow path 13 is connected to the ammonia gas supply unit 12, and the other end of the ammonia gas flow path 13 is connected to the air flow path 15.

[0020] The air supply unit 14 has a function of supplying air, which is an oxidizing gas, to the combustion catalyst unit 16. The air supply unit 14 has a blower. The air supply unit 14 has a function of adjusting the amount of air to be supplied. The air from the air supply unit 14 is mixed with ammonia gas supplied from the ammonia gas flow path 13 in the air flow path 15 and supplied to the combustion catalyst unit 16. The air flow path 15 is a flow path that distributes air for combustion from the air supply unit 14 to the combustion catalyst unit 16, and is part of the gas flow path unit where ammonia gas from the ammonia gas flow path 13 is mixed. One end of the air flow path 15 is connected to the air supply unit 14, and the other end of the air flow path 15 is connected to the combustion catalyst unit 16.

[0021] The combustion catalyst section 16 includes a honeycomb support (not shown) made of porous ceramics and a combustion catalyst supported on the honeycomb support. The combustion catalyst section 16 corresponds to a heating section that constantly heats ammonia gas, and heats the ammonia gas, which is a mixture of ammonia and air, to a temperature suitable for reforming. The honeycomb support is a honeycomb structure made of porous ceramics such as cordierite, mullite, or silicon nitride. The combustion catalyst supported on the honeycomb support is a catalyst that burns ammonia gas in a temperature range of approximately 200°C to 400°C. The catalytic metal of the combustion catalyst can be V, Cr, Mn, Fe, Co, Ni, Cu, Mo, Ru, Rh, Pd, Ag, W, Re, Os, Ir, or Pt.

[0022] The combustion gas of ammonia gas combusted in the combustion catalyst section 16 is supplied to the ATR catalyst section 18 through the mixed gas flow path 17. The mixed gas flow path 17 is a flow path that distributes the mixed gas from the combustion catalyst section 16 to the ATR catalyst section 18, and is a part of the gas flow path section. One end of the mixed gas flow path 17 is connected to the combustion catalyst section 16, and the other end of the mixed gas flow path 17 is connected to the ATR catalyst section 18.

[0023] The ATR catalyst section 18 includes a honeycomb support (not shown) made of porous ceramics and an ATR catalyst (not shown) supported on the honeycomb support. The honeycomb support is a honeycomb structure made of porous ceramics such as cordierite, mullite, or silicon nitride. The honeycomb support is obtained by extruding a ceramic material kneaded with water and a binder using an extrusion molding machine, cutting the extruded body, drying it, and firing it after drying.

[0024] ATR catalysts are catalysts that reform ammonia gas in autothermal reformers (ATR). ATR catalysts are catalysts that reform ammonia gas by burning the ammonia gas and decomposing it into hydrogen using the heat of combustion of the ammonia gas.

[0025] ATR catalysts burn ammonia gas at temperatures between about 200°C and 400°C, and reform the ammonia gas at temperatures higher than the ammonia gas combustion temperature (for example, between about 250°C and 500°C). ATR catalysts include a combustion catalyst that burns ammonia gas and a reforming catalyst that reforms the ammonia gas into hydrogen. Examples of catalytic metals that can be used for the combustion catalyst include V, Cr, Mn, Fe, Co, Ni, Cu, Mo, Ru, Rh, Pd, Ag, W, Re, Os, Ir, and Pt. Examples of catalytic metals that can be used for the reforming catalyst include V, Cr, Mn, Fe, Co, Ni, Cu, Mo, Ru, Rh, Pd, Ag, W, Re, Os, Ir, and Pt.

[0026] Book Reference example The ATR catalyst is a mixed catalyst that combines a combustion catalyst that burns ammonia gas and a reforming catalyst that reforms the ammonia gas into hydrogen. If the combustion reaction rate of ammonia gas by the combustion catalyst (rA) is the reaction rate of ammonia gas reformed by the reforming catalyst (rD), the ATR catalyst of this embodiment combines the combustion catalyst and the reforming catalyst so that the reaction rate ratio (rA / rD) is less than 1. In other words, the ATR catalyst is a reforming-dominated mixed catalyst in which the reforming reaction rate (rD) is greater than the combustion reaction rate (rA). Furthermore, the ATR catalyst combines the combustion catalyst and the reforming catalyst so that the reaction rate ratio between the combustion reaction rate of ammonia gas by the combustion catalyst and the reforming reaction rate of ammonia gas by the reforming catalyst is less than a threshold value (1.0). In a reforming-dominant ATR catalyst, the reforming of ammonia by the reforming catalyst prevails over the combustion of ammonia by the combustion catalyst. An ATR catalyst with a reaction rate ratio (rA / rD) of 1 or more is a combustion-dominant mixed catalyst, in which the combustion of ammonia by the combustion catalyst prevails over the reforming of ammonia by the reforming catalyst.

[0027] Book Reference exampleA reformed gas utilization device 20 that utilizes the reformed gas reformed by the ammonia gas reformer 11 is provided downstream of the ammonia gas reformer 11. The reformed gas reformed in the ATR catalyst section 18 is supplied to the reformed gas utilization device 20 through a reformed gas flow path 19. The reformed gas flow path 19 is a flow path that distributes the reformed gas from the ATR catalyst section 18 to the reformed gas utilization device 20 and is a part of the gas flow path section. Therefore, the ammonia gas reformer 11 reforms ammonia gas to generate the reformed gas, and the generated reformed gas is utilized in the reformed gas utilization device 20.

[0028] Next, the reforming of ammonia gas by the ammonia gas reformer 11 according to this embodiment will be described. In FIG. 2(a), the temperature changes in the combustion catalyst section 16 and the ATR catalyst section 18 of this embodiment are shown by solid lines. In FIG. 2, the lower limit temperature at which ammonia gas is efficiently reformed is T1, and the upper limit temperature at which the ammonia gas reformer 11 is not damaged or deteriorated is T2. After passing through the ammonia gas flow path 13 and the air flow path 15, the ammonia gas is heated by the combustion catalyst in the combustion catalyst section 16 to a temperature above the lower limit temperature T1 but below the upper limit temperature T2 (see FIG. 2). After being heated to a temperature near a temperature suitable for reforming, the ammonia gas passes through the mixed gas flow path 17 and is introduced into the ATR catalyst section 18. In the ATR catalyst section 18, a reforming reaction proceeds using the ammonia combustion heat generated in the combustion catalyst section 16 and the ammonia combustion heat within the ATR catalyst section 18.

[0029] The dashed-dotted line graph in FIG. 2(b) shows Comparative Example 1, an ammonia gas reformer that does not have an upstream combustion catalyst section 16 and only has an ATR catalyst. Patent Document 1 corresponds to this comparative example. In Comparative Example 1, because it is necessary to raise the temperature in the ATR catalyst section 18 to a temperature suitable for reforming, attempting to improve reforming efficiency results in an excessive temperature rise upstream, causing the upper limit temperature T2 to be exceeded. Alternatively, if the temperature rise is insufficient, the temperature drops significantly downstream and falls below the lower limit temperature T1. The dotted line graph in FIG. 2(c) shows Comparative Example 2, an ammonia gas reformer that replaces the ATR catalyst section 18 with a reforming catalyst. Patent Document 2 corresponds to this example. In Comparative Example 2, no combustion reaction occurs in the reforming catalyst section, and the reforming reaction proceeds solely using heat supplied from the upstream 18. As a result, the temperature drops significantly downstream of the reforming catalyst section, falling below the lower limit temperature T1.

[0030] Book Reference example The ammonia gas reforming device 11 according to the present invention has the following advantages. (1) The air required for the combustion reaction in the ATR catalyst section 18 is supplied together with the ammonia gas from the gas flow passage section through which the ammonia gas flows. In addition, the ammonia gas and air are constantly heated in the combustion catalyst section 16. Therefore, the heat required for the reforming reaction in the ATR catalyst section 18 is supplied via the ammonia gas from the combustion catalyst section 16 provided upstream. As a result, the ATR catalyst section 18 can obtain sufficient heat required for reforming the ammonia gas. In addition, combustion in the combustion catalyst section 16 prevents an excessive temperature rise in the ATR catalyst section 18 downstream of the combustion catalyst section 16.

[0031] (2) In addition, since the ammonia gas and air are constantly heated in the combustion catalyst section 16, the ATR catalyst has a high reforming reaction rate (r D ) is the combustion reaction rate (r A ), which is a mixed catalyst with a reforming advantage. Therefore, highly efficient reforming is possible in the ATR catalyst section 18. Furthermore, the combustion heat in the ATR catalyst section 18 may be small.

[0032] Book Reference exampleIn the first embodiment, the combustion catalyst section 16 and the ATR catalyst section 18, which are heating sections, are separate bodies, but this is not limiting. As a modification of the first embodiment, for example, as shown in FIG. 3, the combustion catalyst section 16 and the ATR catalyst section 18 may be integrated. By supporting both the combustion catalyst and the ATR catalyst on a single honeycomb support, the combustion catalyst section 16 and the ATR catalyst section 18 can be integrated. By integrating the combustion catalyst section 16 and the ATR catalyst section 18, the device can be made more compact.

[0033] (No. 1 (embodiment of the invention) Next, 1 An ammonia gas reforming apparatus according to the second embodiment will be described. This embodiment differs from the first embodiment in that an upstream air supply unit is provided that supplies air downstream of the combustion catalyst unit and upstream of the ATR catalyst unit. In this embodiment, the same components as those in the first embodiment will be referred to and will use the same reference numerals.

[0034] As shown in Fig. 4(a), the ammonia gas reforming apparatus 21 of this embodiment has an upstream air supply unit 22. The upstream air supply unit 22 and the ATR catalyst unit 18 are connected via the mixed gas flow path 17 and the upstream air flow path 23. The upstream air supply unit 22 is, for example, a blower, and has a function of continuously or intermittently supplying air to the mixed gas flow path 17. Furthermore, when the ATR catalyst unit 18 does not require air from the upstream air supply unit 22, the upstream air supply unit 22 may be temporarily stopped.

[0035] In this embodiment, not only the air supplied from the air supply unit 14 but also the air supplied from the upstream air supply unit 22 is used in the combustion reaction in the ATR catalyst unit 18. In other words, because the air supplied from the upstream air supply unit 22 can be used for combustion, the temperature can be increased near the inlet of the ATR catalyst unit 18, as shown in FIG. 4(b). Therefore, the ATR catalyst unit 18 can compensate for the shortage of air supplied from the air supply unit 14 with air supplied from the upstream air supply unit 22, making it easier to obtain the heat required for reforming compared to the first embodiment, and improving reforming efficiency. Furthermore, because the air supplied to the ATR catalyst unit 18 can be adjusted not only by the air supplied from the air supply unit 14 but also by combining it with the air from the upstream air supply unit 22, the reforming efficiency can be adjusted by the amount of air supplied from the upstream air supply unit 22.

[0036] (No. 2 (embodiment of the invention) Next, 2 In this embodiment, the ATR catalytic section has an upstream catalytic section and a downstream catalytic section, and the reaction rate ratio of the downstream catalytic section is greater than the reaction rate ratio of the upstream catalytic section. Reference example In this embodiment, Reference example For the same configuration Reference example The explanation of the first embodiment will be referred to and common symbols will be used.

[0037] As shown in Fig. 5(a), the ammonia gas reformer 31 of this embodiment has an ATR catalytic section 32. The ATR catalytic section 32 has an upstream catalytic section 33 downstream of the combustion catalytic section 16, and further downstream of that, a downstream catalytic section 34. The upstream catalytic section 33 and the downstream catalytic section 34 are integrated together. In other words, the upstream catalytic section 33 and the downstream catalytic section 34 are supported on a single honeycomb support.

[0038] The upstream catalytic section 33 has a reforming reaction rate (r D ) is the combustion reaction rate (r A) is a reforming-dominant mixed catalyst. In other words, the upstream catalytic section 33 mixes the combustion catalyst and the reforming catalyst so that the reaction rate ratio between the combustion reaction rate of ammonia gas and the reforming reaction rate of ammonia gas by the reforming catalyst is less than the threshold value (1.0). On the other hand, the downstream catalytic section 34 mixes the combustion catalyst and the reforming catalyst so that the reaction rate ratio between the combustion reaction rate of ammonia gas and the reforming reaction rate of ammonia gas by the reforming catalyst is less than the threshold value (1.0). D ) is the combustion reaction rate (r A ) is a combustion-dominant mixed catalyst having a smaller reaction rate than the combustion rate of the ammonia gas. In other words, the combustion catalyst and the reforming catalyst are mixed in the downstream catalytic section 34 so that the reaction rate ratio between the combustion reaction rate of the ammonia gas and the reforming reaction rate of the ammonia gas by the reforming catalyst is equal to or greater than a threshold value (1.0).

[0039] In this embodiment, the downstream catalytic section 34 has a combustion advantage over the upstream catalytic section 33, and therefore, even if the temperature drops due to the reforming reaction in the upstream catalytic section 33, it is possible to increase the temperature near the inlet of the downstream catalytic section 34, as shown in Fig. 5(b). Therefore, it becomes easier to obtain the heat required for reforming in the downstream catalytic section 34 compared to the first embodiment, and reforming efficiency is improved.

[0040] The upstream catalytic section 33 and the downstream catalytic section 34 are both reforming reaction rates (r D ) is the combustion reaction rate (r A ), and the reaction rate ratio of the downstream catalytic section 34 may be greater than the reaction rate ratio of the upstream catalytic section 33.

[0041] (No. 3 (embodiment of the invention) Next, 3 An ammonia gas reforming apparatus according to the present embodiment will be described. In this embodiment, the ATR catalyst section has an upstream catalyst section and a downstream catalyst section which are separate from each other, and has an upstream air supply section which supplies air to the upstream catalyst section, and a downstream air supply section which supplies air to the downstream catalyst section. In this embodiment, Reference example , th 1 Regarding the same configuration as the embodiment Reference example , th 1 The description of the embodiment will be incorporated herein by reference, and common reference numerals will be used.

[0042] As shown in FIG. 6(a), an ammonia gas reforming apparatus 41 of this embodiment has an ATR catalytic section 42. The ATR catalytic section 42 has an upstream catalytic section 43 downstream of the combustion catalytic section 16, and further has a downstream catalytic section 44 downstream of the upstream catalytic section 43. The upstream catalytic section 43 and the downstream catalytic section 44 are separate bodies and are supported on corresponding honeycomb supports (not shown). The upstream catalytic section 43 and the downstream catalytic section 44 are connected by an intermediate flow path 45. The upstream air supply section 22 and the upstream catalytic section 43 are connected via the upstream air flow path 23. Similarly, the downstream air supply section 46 and the downstream catalytic section 44 are connected via the downstream air flow path 47.

[0043] In this embodiment, the upstream catalytic section 43 is configured to reduce the reforming reaction rate (r D ) is the combustion reaction rate (r A ) is a reforming-dominant mixed catalyst. In other words, the upstream catalytic section 43 mixes the combustion catalyst and the reforming catalyst so that the reaction rate ratio between the combustion reaction rate of ammonia gas and the reforming reaction rate of ammonia gas by the reforming catalyst is less than the threshold value (1.0). On the other hand, the downstream catalytic section 44 has a reforming reaction rate (r D ) is the combustion reaction rate (r A ) is a combustion-dominant mixed catalyst having a smaller reaction rate than the combustion rate of the ammonia gas. In other words, the combustion catalyst and the reforming catalyst are mixed in the downstream catalytic section 44 so that the reaction rate ratio between the combustion reaction rate of the ammonia gas and the reforming reaction rate of the ammonia gas by the reforming catalyst is equal to or greater than a threshold value (1.0).

[0044] In this embodiment, the reaction rate ratio (r A / r D 6(b), it is possible to increase the temperature near the inlet of the upstream catalytic section 43, and also near the inlet of the downstream catalytic section 44. Therefore, compared to the third embodiment, it is easier to obtain the heat required for reforming, and reforming efficiency is improved.

[0045] In the above embodiment, the upstream air supply unit 22 and the downstream air supply unit 46 may be configured to have an air supply amount adjustment mechanism (not shown) that adjusts the amount of air supplied. In such a configuration, the air supply amount adjustment mechanism adjusts the amount of air supplied, and the oxygen required for the combustion reaction of ammonia gas can be supplied in just the right amount, preventing damage and deterioration of the device due to an excessive temperature rise and a decrease in the reforming efficiency of ammonia gas due to a lack of heat.

[0046] The present invention is not limited to the above-described embodiment (including modified examples), and various modifications are possible within the scope of the spirit of the invention. For example, the following modifications may be made.

[0047] The above item 3 In the embodiment, the upstream catalytic section 43 is a reforming-dominated mixed catalyst in which the reforming reaction rate (rD) is greater than the combustion reaction rate (rA), and the downstream catalytic section 44 is a combustion-dominated mixed catalyst in which the reforming reaction rate (rD) is smaller than the combustion reaction rate (rA), but this is not limiting. For example, both the upstream catalytic section 43 and the downstream catalytic section 44 may be reforming-dominant mixed catalysts in which the reforming reaction rate (rD) is greater than the combustion reaction rate (rA), and the reaction rate ratio of the downstream catalytic section 44 may be greater than the reaction rate ratio of the upstream catalytic section 43. [Explanation of symbols]

[0048] 11, 21, 31, 41 Ammonia gas reformer 12 Ammonia gas supply unit 13 Ammonia gas flow path 14 Air supply section 15 Air flow path 16 Combustion catalyst section 17 Mixed gas flow path 18, 32, 42 ATR catalyst section 19 Reformed gas flow path 20. Reformed gas utilization device 22 Upstream air supply section 23 Upstream air flow path 33, 43 Upstream catalyst section 34, 44 Downstream catalyst section 45 Intermediate flow path 46 Downstream air supply section 47 Downstream air flow path r A Combustion Reaction Rate r D Reformation reaction rate r A / r D Reaction rate ratio

Claims

1. a gas flow path portion through which ammonia gas flows; an ATR catalyst section provided in the gas flow path section and including a combustion catalyst for burning ammonia gas and a reforming catalyst for reforming the ammonia gas, a heating section provided upstream of the ATR catalyst section in the gas flow channel section, the heating section constantly heating the ammonia gas; an upstream air supply unit that supplies air to a portion of the gas flow path between the heating unit and the ATR catalyst unit; the heating unit has a combustion catalyst, 10. An ammonia gas reforming apparatus, wherein the heating section and the ATR catalyst are separate bodies and are connected to each other via the gas flow path section.

2. A gas flow path portion through which ammonia gas flows; an ATR catalyst section provided in the gas flow path section and including a combustion catalyst for burning ammonia gas and a reforming catalyst for reforming the ammonia gas, a heating section provided upstream of the ATR catalyst section in the gas flow channel section, the heating section constantly heating the ammonia gas; The ATR catalyst portion is an upstream catalytic portion located upstream; a downstream catalytic section located downstream of the upstream catalytic section and having a higher combustion reaction rate than the upstream catalytic section, the heating unit has a combustion catalyst, The ammonia gas reforming apparatus is characterized in that the heating section and the ATR catalyst are separate bodies and are connected to each other via the gas flow path section.

3. The ATR catalyst portion an upstream catalytic portion located upstream; 2. The ammonia gas reforming apparatus according to claim 1, further comprising: a downstream catalytic section located downstream of said upstream catalytic section and having a combustion reaction rate higher than that of said upstream catalytic section.

4. 4. The ammonia gas reforming apparatus according to claim 2, further comprising a downstream air supply section for supplying air between the upstream catalytic section and the downstream catalytic section.

5. An ammonia gas reforming device as described in any one of claims 1 to 4, characterized in that the ATR catalyst section has a reforming reaction rate that is greater than the combustion reaction rate.

6. 4. The ammonia gas reforming apparatus according to claim 1, wherein the upstream air supply section has an air supply amount adjusting mechanism for adjusting the amount of air supplied.

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