Fuel cell module and fuel cell device

Abstract

A fuel cell module according to the present invention comprises a container, a fuel cell, a combustion unit and a first reactor. The fuel cell supplies an unreacted fuel to the combustion unit through a channel for an exhaust gas that contains the unreacted fuel. The combustion unit combusts the unreacted fuel. The first reactor faces the combustion unit. The first reactor generates at least hydrogen and a dehydrogenation product from an organic hydride by means of a dehydrogenation reaction.

Description

Fuel cell module and fuel cell device CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Japanese Patent Application No. 2022-114389, filed on July 15, 2022, the entire disclosure of which is incorporated herein by reference.

[0002] The present disclosure relates to a fuel cell module and a fuel cell device.

[0003] It is known that organic hydrides are used for the stable storage and transportation of hydrogen in the utilization of hydrogen energy. Dehydrogenation of organic hydrides is generally an endothermic reaction, so a heat source is required. In fuel cells that generate electricity using hydrogen as a reaction source, high temperatures are generated during the power generation reaction, so it has been proposed to use organic hydrides as a heat source (see Patent Document 1).

[0004] JP 2013-143179 A

[0005] A fuel cell module according to a first aspect comprises: a container; a fuel cell housed in the container; a combustion section housed in the container and supplied through a flow path of exhaust gas containing unreacted fuel in the fuel cell, for combusting the unreacted fuel; and a first reactor housed in the container, facing the combustion section, for producing at least hydrogen and a dehydrogenated product from an organic hydride by a dehydrogenation reaction, wherein at least a portion of the hydrogen produced by the first reactor is supplied to the fuel cell as the fuel.

[0006] A fuel cell device according to a second aspect comprises: a fuel cell module having a container, a fuel cell housed in the container, a combustion section housed in the container and supplied through a flow path for exhaust gas containing unreacted fuel in the fuel cell, and combusting the unreacted fuel; a first reactor housed in the container, facing the combustion section, and producing at least hydrogen and a dehydrogenated product from an organic hydride by a dehydrogenation reaction, wherein at least a portion of the hydrogen produced in the first reactor is supplied to the fuel cell; and a storage section connected to the first reactor via a first heat exchanger and a second heat exchanger, and storing the dehydrogenated product.

[0007] The present invention relates to a fuel cell module and a method for manufacturing the same, and more particularly to a fuel cell device including a fuel cell module and a combustion unit.

[0008] Hereinafter, an embodiment of a fuel cell module to which the present disclosure is applied will be described with reference to the drawings.

[0009] 1 , a fuel cell device 11 including a fuel cell module 10 according to an embodiment of the present disclosure includes the fuel cell module 10, a first heat exchanger 12, a second heat exchanger 13, and a storage section 14. The fuel cell device 11 may further include a third heat exchanger 15, a radiator 16, a first supply path 17, and a second supply path 18.

[0010] The fuel cell module 10 includes a container 19, a fuel cell 20, a combustion section 21, and a first reactor 22. The fuel cell module 10 may further include a second reactor 23.

[0011] The vessel 19 houses a fuel cell 20, a combustion section 21, and a first reactor 22. The vessel 19 may house a second reactor 23.

[0012] The fuel cell 20 may be a cell stack in which fuel cell units are stacked. The fuel cell 20 may include a plurality of cell stacks. The fuel cell unit is, for example, a solid oxide fuel cell (SOFC), and generates electricity through an electrochemical reaction using oxygen-containing gas contained in the air and a fuel such as hydrogen delivered from the first reactor 22, as described below. The fuel cell 20 also produces water through the electrochemical reaction. The fuel cell 20 emits exhaust gas containing at least unreacted fuel, unreacted oxygen, and water vapor. Since the fuel cell 20 operates at a high temperature of, for example, 700°C or higher in an SOFC, the exhaust gas is also high in temperature. The exhaust gas from the fuel cell 20 is supplied to the combustion unit 21 via an exhaust gas flow path.

[0013] The combustion unit 21 combusts unreacted fuel contained in exhaust gas supplied from the fuel cell 20. The combustion unit 21 combusts the unreacted fuel, for example, using an oxidizer that has not reacted in the fuel cell 20. The combustion unit 21 may have, for example, a plurality of gas outlets. The plurality of gas outlets may be distributed on a plane. Alternatively, the plurality of gas outlets may be distributed on the inner circumferential surface of a cylinder.

[0014] The combustion unit 21 may be positioned alongside the fuel cell 20 in a direction perpendicular to or parallel to the stacking direction of the fuel cell cells that make up the fuel cell 20. In a configuration in which the combustion unit 21 is positioned alongside the fuel cell 20, the multiple gas outlets may be provided so as to be dispersed along the stacking direction.

[0015] The first reactor 22 is provided so as to face the combustion section 21. As shown in Fig. 2, the first reactor 22 may be provided so as to face a surface 24 on which the gas outlets are provided, in the case of the combustion section 21 in which a plurality of gas outlets are located in a distributed manner on a plane. Alternatively, as shown in Fig. 3, the first reactor 22 may be provided so as to face the inner circumferential surface 25 in a configuration in which a plurality of gas outlets are located in a distributed manner on the inner circumferential surface 25 of a cylinder.

[0016] 2 and 3 , an organic hydride may be supplied to the first reactor 22, as described below. The organic hydride is an organic compound capable of reversibly releasing hydrogen, such as methylcyclohexane, cyclohexane, or decalin. The first reactor 22 produces at least hydrogen and a dehydrogenated product from the organic hydride through a dehydrogenation reaction. A raw fuel gas containing hydrogen, a dehydrogenated product, and unreacted organic hydride may be output from the first reactor 22. At least a portion of the hydrogen contained in the raw fuel gas is supplied to the fuel cell 20 as fuel, as described below.

[0017] The first reactor 22 may have a first vaporization section 26 and a dehydrogenation section 27. The first vaporization section 26 and the dehydrogenation section 27 may be separated by, for example, an inner wall within the first reactor 22. The first vaporization section 26 and the dehydrogenation section 27 may be in communication with each other. The first reactor 22 may be provided within the fuel cell module 10 so that the dehydrogenation section 27 is located downstream of the first vaporization section 26.

[0018] The first vaporization section 26 may vaporize the organic hydride. The first vaporization section 26 may be filled with a filler to promote vaporization. The dehydrogenation section 27 may contain a dehydrogenation catalyst. The dehydrogenation section 27 may cause a dehydrogenation reaction of the organic hydride vaporized in the first vaporization section 26.

[0019] The second reactor 23 may be located between the first reactor 22 and the combustion section 21. The second reactor 23 may be supplied with the separated gas and water generated by combustion in the combustion section 21. As will be described later, the separated gas is delivered from the first reactor 22 and may contain hydrogen and organic compounds supplied together with the hydrogen.

[0020] The second reactor 23 produces hydrogen and carbon dioxide from organic compounds, for example, by a steam reforming reaction. The hydrogen supplied to the second reactor 23 may be discharged as is. The second reactor 23 may discharge hydrogen, carbon dioxide, and unreacted steam. The fuel gas produced by the second reactor 23 is supplied to the fuel cell 20.

[0021] The second reactor 23 may have a second vaporization section 28 and a reforming section 29. The second vaporization section 28 and the reforming section 29 may be separated within the second reactor 23, for example, by an inner wall. The second vaporization section 28 and the reforming section 29 may be in communication with each other. The second reactor 23 may be provided within the fuel cell module 10 so that the reforming section 29 is located downstream of the second vaporization section 28. Within the fuel cell module 10, the second vaporization section 28 may be located apart from the first vaporization section 26. Specifically, the first vaporization section 26 and the second vaporization section 28 may be located apart from each other when viewed from the side-by-side direction in which the first reactor 22 and the second reactor 23 are arranged. Furthermore, specifically, the first vaporization section 26 may be located at one end of the side-by-side direction, and the second vaporization section 28 may be located at the other end.

[0022] The second vaporization unit 28 may vaporize water. The second vaporization unit 28 may be filled with a filler to promote vaporization. The reforming unit 29 may contain a reforming catalyst. The reforming unit 29 may cause a reforming reaction of the organic compound using the water vaporized in the second vaporization unit 28.

[0023] The combustion unit 21, the first reactor 22, and the second reactor 23 may be provided at any position in any orientation within the container 19. For example, the combustion unit 21, the first reactor 22, and the second reactor 23 may be provided vertically above the fuel cell 20 when the fuel cell device 11 is in the correct installation orientation. Alternatively, the combustion unit 21, the first reactor 22, and the second reactor 23 may be provided to the side of the fuel cell 20 when the fuel cell device 11 is in the correct installation orientation. A partition wall may be provided between the combustion unit 21 and the fuel cell 20.

[0024] As shown in FIG. 1 , the first heat exchanger 12 may exchange heat between the raw fuel gas delivered from the first reactor 22 and the oxygen-containing gas supplied to the fuel cell 20. The raw fuel gas delivered from the first reactor 22 may be cooled by heat exchange with the oxygen-containing gas, thereby liquefying components having low boiling points in the raw fuel gas. The components having low boiling points in the raw fuel gas may be dehydrogenated products and organic hydrides. The oxygen-containing gas may be pressurized using, for example, a blower or the like, before being delivered to the first heat exchanger 12. The oxygen-containing gas may be heated by heat exchange and supplied to the fuel cell 20.

[0025] The second heat exchanger 13 may exchange heat between the raw fuel gas that has undergone heat exchange in the first heat exchanger 12 and a heat medium. Liquefied components may also be supplied to the second heat exchanger 13 together with the raw fuel gas. The heat medium may be a liquid. The heat medium may be water. The raw fuel gas delivered from the first heat exchanger 12 may be further cooled by heat exchange with the heat medium, thereby further liquefying components with low boiling points.

[0026] The storage unit 14 may be connected to the first reactor 22 via the first heat exchanger 12 and the second heat exchanger 13. The storage unit 14 may store a dehydrogenated product contained in the raw fuel gas. The storage unit 14 may store an organic hydride contained in the raw fuel gas. The storage unit 14 may, for example, separate the dehydrogenated product and organic hydride liquefied by heat exchange in the first heat exchanger 12 and the second heat exchanger 13 from the hydrogen gas and store the separated product. The liquefied dehydrogenated product and organic hydride may be separated from the hydrogen gas by, for example, a first gas-liquid separator 30 provided between the second heat exchanger 13 and the storage unit 14. The first gas-liquid separator 30 may supply a separated gas containing hydrogen gas separated from the raw fuel gas to the second reactor 23. The separated gas may contain the gaseous dehydrogenated product and organic hydride that were not liquefied as the organic compounds described above.

[0027] The third heat exchanger 15 may exchange heat between the exhaust gas discharged from the fuel cell module 10 and the heat medium that has undergone heat exchange in the second heat exchanger 13. Specifically, the exhaust gas discharged from the fuel cell module 10 may be exhaust gas combusted in the combustion section 21. The exhaust gas may contain carbon dioxide, oxygen, water vapor, nitrogen, etc. The exhaust gas from the fuel cell module 10 may be cooled by heat exchange with the heat medium, thereby liquefying the water vapor in the exhaust gas.

[0028] The water liquefied by heat exchange in the third heat exchanger 15 may be separated from the exhaust gas by the second gas-liquid separator 31. The separated water may be stored in the reforming water tank 32. The water stored in the reforming water tank 32 may be pressurized by the pump 33 and supplied to the second reactor 23.

[0029] The radiator 16 may cool the heat medium that has undergone heat exchange in the third heat exchanger 15. The radiator 16 may circulate the cooled heat medium to the second heat exchanger 13. The radiator 16 is, for example, a radiator. Heat may be recovered from the heat medium that has undergone heat exchange in the third heat exchanger 15 and utilized.

[0030] The first reactor 22 may be switchably connected to a first supply path 17 and a second supply path 18. For example, the first reactor 22 may be connected to the first supply path 17 and the second supply path 18 via a three-way valve 34. An organic hydride may be supplied to the first supply path 17 from outside the fuel cell device 11. A first fuel may be supplied to the second supply path 18 from outside the fuel cell device 11. The first fuel may be a substance that can be used as a fuel for the fuel cell 20. The first fuel is, for example, hydrogen.

[0031] The fuel cell module 10 of this embodiment, configured as described above, includes a combustion unit 21 that combusts unreacted fuel supplied to the fuel cell 20 through a flow path for exhaust gas containing the unreacted fuel, and a first reactor 22 that faces the combustion unit 21 and produces at least hydrogen and a dehydrogenated product from organic hydride through a dehydrogenation reaction, with at least a portion of the hydrogen produced in the first reactor 22 being supplied to the fuel cell 20 as fuel. With this configuration, the fuel cell module 10 can utilize high-temperature heat for operating the fuel cell 20 for the endothermic reaction of the organic hydride, while also utilizing high-temperature heat generated by the combustion of the unreacted fuel for the endothermic reaction of the organic hydride. Therefore, the fuel cell module 10, with a relatively simple configuration such as the combustion unit 21, can stably generate electricity even when the amount of heat required for operating the fuel cell 20 fluctuates depending on the amount of power generation.

[0032] The fuel cell module 10 also includes a second reactor 23 located between the first reactor 22 and the combustion section 21, which reforms organic compounds discharged from the first reactor 22 and supplied together with hydrogen. While the hydrogen contained in the raw fuel gas discharged from the first reactor 22 is separated from organic compounds such as dehydrogenated products and organic hydrides using a first gas-liquid separator 30 or the like, complete separation is difficult. Therefore, it is common for some organic compounds to be discharged together with hydrogen into the supply path of the fuel cell 20. To address this issue, the fuel cell module 10 configured as described above reforms the contaminated organic compounds into hydrogen, thereby reducing the impact of the organic compounds being supplied to the fuel cell 20.

[0033] Furthermore, in the fuel cell module 10, the second vaporization section 28 constituting the second reactor 23 is located away from the first vaporization section 26 constituting the first reactor 22. In both the first reactor 22 and the second reactor 23, the vaporization of the organic hydride and water at room temperature absorbs more heat than the dehydrogenation reaction and reforming reaction in the subsequent stages. Therefore, the temperature drop near the first vaporization section 26 and the second vaporization section 28 is large. To address this issue, the fuel cell module 10 having the above-described configuration can homogenize the temperature distribution throughout the first reactor 22 and the second reactor 23. By homogenizing the temperature distribution, the fuel cell module 10 can contribute to homogenizing the temperature distribution of, for example, the fuel cell cells constituting the fuel cell 20.

[0034] The fuel cell device 11 of this embodiment also includes a fuel cell module 10 and a storage unit 14 that stores the dehydrogenated product and is connected to the first reactor 22 via a first heat exchanger 12 and a second heat exchanger 13. With this configuration, the fuel cell device 11 can recover the dehydrogenated product, which can be used for storing and transporting hydrogen, and use it as a raw material for hydrogenation at the hydrogen supply site.

[0035] Furthermore, in the fuel cell device 11 of this embodiment, the first heat exchanger 12 exchanges heat between the raw fuel gas delivered from the first reactor 22 and the oxygen-containing gas supplied to the fuel cell 20. The higher the temperature of the oxygen-containing gas supplied to the fuel cell 20, the more efficient the power generation. In such a situation, the fuel cell device 11 having the above-described configuration can effectively utilize the heat of the raw fuel gas that needs to be cooled.

[0036] Furthermore, in the fuel cell device 11 of this embodiment, the second heat exchanger 13 exchanges heat between the raw fuel gas that has undergone heat exchange in the first heat exchanger 12 and a heat medium. With this configuration, the fuel cell device 11 can further cool the raw fuel gas, thereby improving the amount of dehydrogenated products recovered.

[0037] The fuel cell device 11 of this embodiment also includes a third heat exchanger 15 that exchanges heat between the exhaust gas discharged from the fuel cell module 10 and the heat medium that has undergone heat exchange in the second heat exchanger 13. With this configuration, the fuel cell device 11 shares the supply path for the heat medium for recovering reforming water from the exhaust gas with the supply path for the heat medium for cooling the raw fuel gas, thereby simplifying the configuration.

[0038] The fuel cell device 11 of this embodiment also includes a radiator 16 that cools the heat medium that has undergone heat exchange in the third heat exchanger 15 and circulates the cooled heat medium to the second heat exchanger 13. With this configuration, the fuel cell device 11 can sufficiently cool the heat medium and maintain the recovery amounts of the dehydrogenated product and reformed water.

[0039] Furthermore, in the fuel cell device 11 of this embodiment, the first supply path 17 that supplies the organic hydride to the first reactor 22 and the second supply path 18 that supplies the first fuel are switchably connected. After the fuel cell 20 starts operating and before power generation begins, the temperature around the fuel cell 20 may be low and sufficient heat for dehydrogenation may not be generated. To cope with such an event, the fuel cell device 11 having the above-described configuration can directly supply the first fuel to the fuel cell 20 via the second supply path 18. Therefore, the fuel cell device 11 can start supplying the first fuel to the fuel cell 20 even at a relatively low temperature.

[0040] In one embodiment, (1) a fuel cell module includes: a container; a fuel cell housed in the container; a combustion unit housed in the container and supplied through a flow path for exhaust gas containing unreacted fuel in the fuel cell, for combusting the unreacted fuel; and a first reactor housed in the container, facing the combustion unit, for producing at least hydrogen and a dehydrogenated product from an organic hydride by a dehydrogenation reaction, and at least a portion of the hydrogen produced by the first reactor is supplied to the fuel cell as the fuel.

[0041] (2) In the fuel cell module of (1) above, in the fuel cell module described in claim 1, the first reactor has a first vaporization section that vaporizes the organic hydride, and a dehydrogenation section that is provided downstream of the first vaporization section and contains a dehydrogenation catalyst.

[0042] (3) The fuel cell module of (2) above further comprises a second reactor housed in the container, positioned between the first reactor and the combustion section, and reforming the organic compound discharged from the first reactor and supplied together with the hydrogen.

[0043] (4) In the fuel cell module of (3) above, the second reactor has a second vaporization section that vaporizes water used to reform the organic compound, and a reforming section that is provided downstream of the second vaporization section and contains a reforming catalyst.

[0044] (5) In the fuel cell module of (4) above, the second vaporization section is disposed apart from the first vaporization section.

[0045] In one embodiment, (6) a fuel cell device includes: a fuel cell module according to any one of (1) to (5) above; and a storage section connected to the first reactor via a first heat exchanger and a second heat exchanger, and configured to store the dehydrogenated product.

[0046] (7) In the fuel cell device of (6) above, the first heat exchanger exchanges heat between the gas delivered from the first reactor and the oxygen-containing gas supplied to the fuel cell.

[0047] (8) In the fuel cell device of (7) above, the second heat exchanger exchanges heat between the gas that has undergone heat exchange in the first heat exchanger and a heat medium.

[0048] (9) The fuel cell device of (8) above further comprises a third heat exchanger that exchanges heat between exhaust gas discharged from the fuel cell module and the heat medium that has undergone heat exchange in the second heat exchanger.

[0049] (10) The fuel cell device of (9) above further comprises a radiator that cools the heat medium that has undergone heat exchange in the third heat exchanger and circulates the cooled heat medium to the second heat exchanger.

[0050] (11) In the fuel cell device according to any one of (6) to (10) above, a first supply path for supplying the organic hydride and a second supply path for supplying the first fuel are switchably connected to the first reactor.

[0051] The drawings illustrating the embodiments of the present disclosure are schematic, and the dimensional ratios and the like in the drawings do not necessarily correspond to the actual ones.

[0052] Although the embodiments of the present disclosure have been described based on the drawings and examples, it should be noted that those skilled in the art could make various modifications or alterations based on the present disclosure. Therefore, it should be noted that these modifications or alterations are included in the scope of the present disclosure. For example, the functions included in each component can be rearranged so as not to cause logical inconsistencies, and multiple components can be combined or divided into one.

[0053] All of the features described in this disclosure and / or all steps of all of the disclosed methods or processes may be combined in any combination except combinations in which these features are mutually exclusive. Furthermore, each feature described in this disclosure may be replaced by an alternative feature serving the same, equivalent, or similar purpose, unless expressly denied. Thus, unless expressly denied, each disclosed feature is only one example of a generic series of identical or equivalent features.

[0054] Furthermore, embodiments of the present disclosure are not limited to the specific configurations of any of the above-described embodiments, but rather extend to any novel feature or combination thereof described herein, or any novel method or process step or combination thereof described herein.

[0055] In this disclosure, descriptions such as "first" and "second" are identifiers for distinguishing the configuration. In this disclosure, the configurations distinguished by descriptions such as "first" and "second" can have their numbers interchanged. For example, the first heat exchanger can have its identifiers "first" and "second" interchanged with the second heat exchanger. The identifiers are interchanged simultaneously. The configurations remain distinguished even after the identifiers are interchanged. Identifiers may be deleted. A configuration from which an identifier has been deleted is distinguished by a symbol. The identifiers "first" and "second" in this disclosure should not be used solely to interpret the order of the configurations or to justify the existence of an identifier with a smaller number.

[0056] REFERENCE SIGNS LIST 10 fuel cell module 11 fuel cell device 12 first heat exchanger 13 second heat exchanger 14 storage section 15 third heat exchanger 16 radiator 17 first supply section 18 second supply section 19 container 20 fuel cell 21 combustion section 22 first reactor 23 second reactor 24 surface on which gas outlet is provided 25 inner circumferential surface 26 first vaporization section 27 dehydrogenation section 28 second vaporization section 29 reforming section 30 first gas-liquid separator 31 second gas-liquid separator 32 reforming water tank 33 pump 34 three-way valve

Claims

1. A container; A fuel cell housed in the container; a combustion section that is accommodated in the container and that combusts unreacted fuel supplied through a flow path of exhaust gas that contains unreacted fuel in the fuel cell; a first reactor that is accommodated in the vessel and faces the combustion section, and that generates at least hydrogen and a dehydrogenated product from an organic hydride by a dehydrogenation reaction; At least a portion of the hydrogen produced in the first reactor is supplied to the fuel cell as the fuel. Fuel cell module.

2. 2. The fuel cell module according to claim 1, The first reactor has a first vaporization section that vaporizes the organic hydride, and a dehydrogenation section that is provided downstream of the first vaporization section and contains a dehydrogenation catalyst. Fuel cell module.

3. 3. The fuel cell module according to claim 2, The apparatus further includes a second reactor, which is housed in the vessel and located between the first reactor and the combustion section, and which reforms an organic compound discharged from the first reactor and supplied together with the hydrogen. Fuel cell module.

4. 4. The fuel cell module according to claim 3, The second reactor has a second vaporization section that vaporizes water used for reforming the organic compound, and a reforming section that is provided downstream of the second vaporization section and contains a reforming catalyst. Fuel cell module.

5. 5. The fuel cell module according to claim 4, The second vaporization unit is disposed apart from the first vaporization unit. Fuel cell module.

6. A fuel cell module according to any one of claims 1 to 5; a storage section connected to the first reactor via a first heat exchanger and a second heat exchanger, and configured to store the dehydrogenated product; Fuel cell device.

7. 7. The fuel cell device according to claim 6, The first heat exchanger exchanges heat between the gas discharged from the first reactor and an oxygen-containing gas supplied to the fuel cell. Fuel cell device.

8. 8. The fuel cell device according to claim 7, The second heat exchanger exchanges heat between the gas that has undergone heat exchange in the first heat exchanger and a heat medium. Fuel cell device.

9. 9. The fuel cell device according to claim 8, a third heat exchanger that exchanges heat between exhaust gas discharged from the fuel cell module and the heat medium that has undergone heat exchange in the second heat exchanger. Fuel cell device.

10. 10. The fuel cell device according to claim 9, The heat exchanger further includes a radiator that cools the heat medium that has undergone heat exchange in the third heat exchanger and circulates the heat medium to the second heat exchanger. Fuel cell device.

11. 7. The fuel cell device according to claim 6, A first supply passage for supplying the organic hydride and a second supply passage for supplying a first fuel are switchably connected to the first reactor. Fuel cell device.