Storage container for hydrogen carrier and storage container for by-product

Abstract

To provide a configuration that can suppress a rise in the pressure inside a storage container 1 for storing a hydrogen carrier or a by-product, even if keeping storage containers 1 in a manner of stacking them in the vertical direction or lay out them in the horizontal direction or the front-rear direction.SOLUTION: A pair of plane parts 16 are provided on two opposite outer wall surfaces of a storage container 1 in at least either of the vertical direction, the horizontal direction, and the front-rear direction in an installation state of the storage container 1. A recessed portion 15 is formed in a portion of at least one 16 of the pair of plane parts 16, and is formed so as to be recessed inward from another portions 16a of the plane part 16, and such that at least a part of the recessed portion is in communication with the outside of the plane part 16 in a direction along the plane part 16. A relief valve 11 is provided in the recessed portion 15, and automatically opens when the pressure inside a storage part 14 for storing a hydrogen carrier exceeds a predetermined value to release a gas inside the storage part 14 to the outside.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a hydrogen carrier storage container and a by-product storage container for storing a hydrogen carrier and a by-product. [Background technology]

[0002] 2. Description of the Related Art A storage container for storing gas has been proposed that has a flat upper and lower surface and can be stacked vertically (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2019 / 026872 Summary of the Invention [Problem to be solved by the invention]

[0004] Here, a device that generates hydrogen by reacting a hydrogen carrier with a liquid containing water has been conventionally known. It has also been conventionally known that at this time, by-products are generated along with hydrogen. When such a hydrogen carrier or by-product is stored in a storage container, there is a risk that gas such as hydrogen may be generated in the storage container depending on the storage environment. In this case, the pressure inside the storage container may increase, causing the storage container to burst, so it is considered to provide a relief valve that releases the gas inside the storage container to the outside.

[0005] However, if storage containers are stored stacked vertically or lined up horizontally or front to back, the relief valve may become blocked, preventing sufficient gas from being discharged from inside the storage container, which may result in an increase in pressure inside the storage container.

[0006] The present invention aims to provide a configuration that can suppress an increase in pressure inside a storage container even if the storage containers for storing hydrogen carriers or by-products are stored stacked vertically or lined up horizontally or front-to-back. [Means for solving the problem]

[0007] The hydrogen carrier storage container of the present invention is a hydrogen carrier storage container capable of storing a hydrogen carrier, and is characterized in that it comprises a storage section for storing the hydrogen carrier, a pair of flat surfaces provided on both sides of the outer wall surface of the storage container in at least one of the up-down, left-right, and front-to-back directions when the storage container is installed, a recess formed in a portion of at least one of the pair of flat surfaces, the recess being recessed more inward than other portions of the flat surface and having at least a portion connected to the outside of the flat surface in a direction along the flat surface, and a relief valve provided within the recess, which automatically opens when the pressure inside the storage section exceeds a predetermined value to release gas inside the storage section to the outside.

[0008] In addition, the by-product storage container of the present invention is a by-product storage container capable of storing by-products produced together with hydrogen when a hydrogen carrier is reacted with a liquid containing water, and is characterized in that it comprises: a storage section for storing the by-products; a pair of flat sections provided on both sides of an outer wall surface of the storage container in at least one of the up-down, left-right, and front-to-back directions when the storage container is installed; a recess formed in a portion of at least one of the pair of flat sections, the recess being recessed more inward than other portions of the flat section and having at least a portion connected to the outside of the flat section in a direction along the flat section; and a relief valve provided within the recess, which automatically opens when the pressure inside the storage section exceeds a predetermined value to release gas inside the storage section to the outside. Effect of the Invention

[0009] According to the present invention, even if storage containers for storing hydrogen carriers or by-products are stacked vertically or arranged side-by-side or front-to-back, an increase in pressure inside the storage containers can be suppressed. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram of a hydrogen generation system according to a first embodiment. [Diagram 2] FIG. 1 is a cross-sectional view showing a schematic configuration of a storage container according to a first embodiment. [Diagram 3] FIG. 1 is a perspective view showing a schematic configuration of a storage container according to a first embodiment. [Figure 4] FIG. 2 is a schematic cross-sectional view showing an example of a storage state of the storage container according to the first embodiment. [Diagram 5] FIG. 2 is a schematic perspective view showing an example of a storage state of the storage container according to the first embodiment. [Figure 6] 10A is a schematic cross-sectional view showing a state in which a storage container according to another example of the first embodiment is fitted, and FIG. 10B is a schematic cross-sectional view showing the storage container in the fitted state. [Figure 7] FIG. 1 is a schematic configuration diagram of a hydrogen generation system according to a second embodiment. [Figure 8] FIG. 11 is a cross-sectional view showing a schematic configuration of a storage container according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] <First embodiment> A first embodiment will be described with reference to Figs. 1 to 5. First, hydrogen has been attracting attention as an alternative energy source to fossil fuels. This is because, unlike fossil fuels, hydrogen does not generate carbon dioxide, a type of greenhouse gas that leads to global warming, when burned. One of the systems that uses hydrogen as an energy source that has been put to practical use is a fuel cell vehicle. A fuel cell vehicle is a vehicle that generates electricity using hydrogen as a raw material and runs by driving an electric motor with the generated electricity. In many fuel cell vehicles, hydrogen, which is an energy source, is stored in a hydrogen tank, and hydrogen discharged from the hydrogen tank is fed into a fuel cell to generate electricity. The hydrogen tank stores hydrogen by compressing it at a high pressure, for example, 70 MPa (700 times atmospheric pressure).

[0012] One of the issues with hydrogen as an energy source is its low energy density. The volumetric energy density of hydrogen is about 1 / 3000 of that of gasoline, so even if a 70MPa hydrogen tank is used, only about 1 / 5 of the energy of gasoline can be extracted from the same volume. For this reason, fuel cell vehicles that use hydrogen tanks generally require more frequent energy refueling than vehicles that use gasoline.

[0013] For this reason, various substances that can transport hydrogen at a higher energy density than hydrogen tanks (i.e., hydrogen carriers) are being considered. For example, borohydrides such as ammonia, methylcyclohexane, and sodium borohydride are known as hydrogen carriers, and hydrogen carriers are transported instead of hydrogen itself, and hydrogen is extracted from the hydrogen carrier when it is used.

[0014] [Hydrogen Carrier] Among hydrogen carriers, metal hydrides such as sodium borohydride are widely known, from which hydrogen can be easily extracted by adding water. As a method for obtaining hydrogen by hydrolysis of sodium borohydride, a method for dissolving sodium borohydride in water and using it as an aqueous solution is known. However, in this method, a problem occurs in that a larger amount of water is required than the theoretically required amount shown in the reaction formula, resulting in a decrease in the actual volumetric energy density. Therefore, in this embodiment, as described later, hydrogen is generated by adding a liquid containing water to the hydrogen carrier in the hydrogen generation device (specifically, by pouring a liquid containing water onto the hydrogen carrier).

[0015] Examples of hydrogen carriers that generate hydrogen by applying a liquid containing water include the following. For example, one or a mixture of solid metal hydrides such as sodium borohydride, potassium borohydride, lithium borohydride, zinc borohydride, lithium aluminum hydride, sodium aluminum hydride, magnesium aluminum hydride, calcium aluminum hydride, magnesium hydride, lithium hydride, sodium hydride, and calcium hydride, and metal powders such as aluminum, zinc, calcium, and magnesium can be used. Organic hydrides such as methylcyclohexane, cyclohexane, and decalin can also be used. Additives such as a reaction promoter and a desiccant may be used together with the hydrogen carrier.

[0016] The hydrogen carrier of the present embodiment is not particularly limited to a solid or liquid, but is preferably a solid. As a solid hydrogen carrier, a solid such as a powder or granule is desirable, but a solid such as a sheet, pellet, or paste can also be used. As the powder, a particle size of about 10 μm to 10 mm can be used, and a particle size of about 10 μm to 3 mm or less, and further a particle size of about 10 μm to 100 μm or less are more preferable. In addition, when using in a sheet or pellet form, it is preferable to increase the surface area and the contact area with the water-containing liquid by performing surface roughening, porous treatment, etc., from the viewpoint of increasing the reactivity with the water-containing liquid.

[0017] The hydrogen carrier of this embodiment is intended to be one that generates by-products (reaction products) other than hydrogen, such as liquid, gel, or solid, after hydrogen is generated by a chemical reaction.

[0018] In this embodiment, sodium borohydride powder with an average particle size of 50 μm is used as the solid hydrogen carrier. The powdered sodium borohydride reacts with water to generate hydrogen. The reacted sodium borohydride changes into sodium metaborate, which is a by-product. Water that is not used in the reaction remains as it is. This reaction is expressed by the following chemical formula. NaBH4 (sodium borohydride) + 2H2O (water) →NaBO2(sodium metaborate)+4H2(hydrogen)···(1)

[0019] This reaction (chemical formula (1)) is known to be accelerated by Raney catalysts made from metals such as nickel, cobalt, and copper, and acidic solutions such as citric acid and acetic acid. In this embodiment, when a larger amount of water than that in formula (1) is added in order to efficiently carry out the hydrolysis reaction throughout, the by-product becomes a liquid sodium metaborate solution or a gel-like sodium borate hydrate.

[0020] [Liquid containing water] The "liquid containing water" in this embodiment is not particularly limited as long as it is a liquid that reacts with the hydrogen carrier when applied and generates hydrogen. That is, the liquid containing water may be water alone. In addition, two or more types of liquid containing water may be prepared. By preparing two or more types of liquid containing water, the rate at which hydrogen is generated can be adjusted.

[0021] The liquid containing water can contain a water-soluble organic solvent. Examples of the water-containing liquid include alcohols, polyalkylene glycols, glycol ethers, nitrogen-containing compounds, and sulfur-containing compounds. Two or more selected from these can be mixed and used. By including a water-soluble organic solvent, the surface tension and the boiling and melting points of the water-containing liquid can be adjusted, thereby optimizing the reaction with the hydrogen carrier.

[0022] A surfactant can be added to the aqueous liquid, which can reduce the surface tension of the aqueous liquid, increasing the contact area with the hydrogen carrier and allowing for an efficient reaction.

[0023] The aqueous liquid may contain a water-soluble acidic substance. The acidic substance acts as a positive catalyst in the reaction between the aqueous liquid and the hydrogen carrier. The hydrogen generation speed can be adjusted by adjusting the amount of the aqueous liquid containing the acidic substance. In particular, the hydrogen generation speed can be increased by making the pH obtained by the aqueous liquid and the hydrogen carrier less than 9.0. Examples of the acidic substance include, but are not limited to, various acids such as hydrochloric acid, sulfuric acid, nitric acid, boric acid, and organic acids.

[0024] The aqueous liquid may contain a water-soluble basic substance. The basic substance acts as a negative catalyst in the reaction between the aqueous liquid and the hydrogen carrier. The hydrogen generation speed can be adjusted by adjusting the amount of the aqueous liquid containing the basic substance. In particular, the hydrogen generation speed can be slowed down by making the pH obtained by the aqueous liquid and the hydrogen carrier 9.0 or higher. Examples of bases include, but are not limited to, various bases such as sodium hydroxide, potassium hydroxide, and ammonia water.

[0025] The liquid containing water may contain a buffer solution. The buffer solution acts to suppress pH changes in the reaction between the liquid containing water and the hydrogen carrier. The speed of hydrogen generation can be adjusted by adjusting the amount of the liquid containing a buffering agent. Examples of buffer solutions include, but are not limited to, various buffer solutions such as phosphate buffer, glycine buffer, Good's buffer, Tris buffer, and ammonia buffer.

[0026] In addition to the above components, the water-containing liquid may contain various additives, such as antifoaming agents, pH adjusters, viscosity adjusters, rust inhibitors, preservatives, antifungal agents, antioxidants, and reduction inhibitors, as necessary.

[0027] [Hydrogen generation system] The hydrogen generation system 100 of this embodiment will be described with reference to Fig. 1. Fig. 1 is a block diagram showing a schematic configuration of the hydrogen generation system 100 of this embodiment. The hydrogen generation system 100 includes a hydrogen carrier storage container 1, a hydrogen generation device 32, a water supply unit 33, and a fuel cell system 35.

[0028] The hydrogen carrier storage container 1 is a container capable of storing a hydrogen carrier (sodium borohydride in this embodiment) and is a container that is detachable from the hydrogen generation device 32. The filled hydrogen carrier is sent by its own weight to the hydrogen generation section of the hydrogen generation device 32, and the supply amount can be adjusted by an opening and closing valve attached to the hydrogen generation section side.

[0029] The storage container 1 also includes a relief valve 11 for releasing hydrogen gas generated inside to the outside, and a filter 13. The filter 13 is provided between the relief valve 11 and the inside of the storage container 1. This filter 13 allows hydrogen gas to pass through but does not allow the hydrogen carrier inside the container to pass through. A detailed description of the storage container 1 will be given later.

[0030] The water supply unit 33 has a function of being able to supply "liquid containing water" from a water supply, a water tank, etc. to the hydrogen generator 32, and a filter or the like is installed in the flow path to remove foreign matter, etc. In addition, for the purpose of promoting and stabilizing the hydrolysis reaction, the water supply unit 33 may have a function of adjusting the temperature of the liquid containing water to be supplied, such as a heater or chiller.

[0031] The hydrogen generating device 32 has a hydrogen generating section, to which the hydrogen carrier is supplied from the storage container 1 and a liquid containing water is supplied from the water supply unit 33. The hydrogen carrier and the liquid containing water are mixed in the hydrogen generating section to cause a hydrolysis reaction and generate hydrogen and by-products.

[0032] The hydrogen generated in the hydrogen generation device 32 is sent to a fuel cell system 35. The fuel cell system 35 generates electricity using the hydrogen generated in the hydrogen generation device 32, and is an example of an apparatus that utilizes the hydrogen generated in the hydrogen generation device 32. A by-product (sodium metaborate in this embodiment) generated during hydrogen generation is collected in a collection container (not shown).

[0033] In such a hydrogen generation system 100, first, after the hydrogen carrier is injected into the storage container 1, if hydrogen is not generated, or if hydrogen is generated but does not exceed a threshold value set in consideration of safety, the hydrogen is delivered directly to the hydrogen generation device 32. Then, the hydrogen carrier is supplied from the storage container 1 and a liquid containing water is supplied from the water supply unit 33 to the hydrogen generation device 32, where hydrogen gas and by-products are produced.

[0034] If for some reason the hydrogen carrier reacts inside the storage container 1 to generate hydrogen gas, causing the pressure inside the storage container 1 to exceed a predetermined value, the relief valve 11 will automatically open and release the excess hydrogen from inside the storage container 1 to the outside.

[0035] [Hydrogen carrier storage vessel] Next, the storage container 1 for the hydrogen carrier will be described with reference to Fig. 2 and Fig. 3. The storage container 1 has a storage section 14 for storing the hydrogen carrier, and has a cylindrical shape with a polygonal cross section perpendicular to the longitudinal direction. In this embodiment, as shown in Fig. 3, the cross section perpendicular to the longitudinal direction of the storage container 1 has a rectangular prism shape. Note that the cross section perpendicular to the longitudinal direction of the storage container 1 may have other shapes such as a pentagon, hexagon, or octagon in addition to a rectangle.

[0036] As described later, the storage container 1 has a flat surface 16 on at least a portion of the outer wall surface, and when stacked vertically or arranged in a horizontal line, the flat surfaces 16 of adjacent storage containers 1 (flat surfaces) face each other and come into contact or close to each other, allowing multiple storage containers 1 to be arranged in a space-saving manner. The storage container 1 is preferably in a prismatic shape that allows efficient stacking in the up-down, front-back, and left-right directions, and as long as this is satisfied, shapes such as a pentagonal, hexagonal, or octagonal prism may be used.

[0037] Moreover, from the viewpoint of preventing static electricity buildup, the storage container 1 is preferably made of metal or a resin container with anti-static measures. This makes it possible to prevent ignition due to the metal even if hydrogen gas is generated inside. Also, as a measure to dehumidify the inside of the storage container 1, there is no problem in particular with sticking a desiccant or the like to the inner wall of the container. This makes it possible to suppress the reaction between the hydrogen carrier and water inside the storage container 1 and suppress the generation of hydrogen gas.

[0038] Such a storage container 1 has a planar portion 16 as a first planar portion, a planar portion 17 as a second planar portion, a recess 15 as a first recess, a relief valve 11, a filter 13, an opening 12, and a recess 18 as a second recess. The planar portions 16 are provided on both sides of the outer wall surface of the storage container 1 in at least one of the up-down direction, the left-right direction, and the front-rear direction when the storage container 1 is installed. By arranging the planar portions 16 in this manner, it is possible to line up the storage containers 1 so that the planar portions 16 are in contact with or close to each other.

[0039] A pair of flat surfaces 16 is preferably provided on the outer wall surface of the storage container 1 in at least two directions among the up-down direction, the left-right direction, and the front-rear direction when the storage container 1 is installed. By arranging the flat surfaces 16 in this manner, it is possible to line up the storage containers 1 so that the flat surfaces 16 are in contact with or close to each other in a plurality of directions. In this embodiment, the storage container 1 has a rectangular column shape with a cross section perpendicular to the longitudinal direction, and therefore a pair of flat surfaces 16 is provided in each of the up-down direction and the left-right direction when the storage container 1 is installed. In this embodiment, the longitudinal direction of the storage container 1 is defined as the front-rear direction.

[0040] In this way, by providing a pair of flat surfaces 16 in each of the vertical and horizontal directions in the installed state, the storage containers 1 can be stacked vertically so that the flat surfaces 16 abut or are close to each other, and the storage containers 1 can also be arranged side by side in the horizontal direction so that the flat surfaces 16 abut or are close to each other. Even if the orientation of the storage container 1 is changed so that the above-mentioned vertical direction becomes the horizontal direction and the horizontal direction becomes the vertical direction, the storage containers 1 can be stacked vertically and arranged side by side in the horizontal direction. The same applies to the relationship between the vertical direction and the front-to-back direction, and the relationship between the left-to-right direction and the front-to-back direction.

[0041] Moreover, in the storage container 1 of this embodiment, a flat surface portion 17 is provided on both sides in the front-rear direction. That is, both longitudinal ends of the storage container 1 also have flat surface portions 17. That is, the flat surface portions 17 are provided at positions different from the flat surface portions 16 on the outer wall surface of the storage container 1, and in this embodiment, both front-rear direction sides of the storage container 1 are flat surface portions 17. The storage containers 1 can be arranged side by side such that the flat surface portions 17 abut or are close to each other in the front-rear direction.

[0042] An opening 12 is formed in one of the flat surface portions 17 on both sides in the front-rear direction. The opening 12 communicates the inside and outside of the storage portion 14, and is provided for injecting or discharging the hydrogen carrier into or from the storage portion 14. A recess 18 is formed in a part of the flat surface portion 17 so as to be recessed inward more than other parts. The opening 12 is provided within the recess 18.

[0043] Opening 12 is formed to fit within recess 18. Opening 12 can be connected without any gaps to a hydrogen carrier inlet of hydrogen generator 32, and is structured to enable the hydrogen carrier filled in storage unit 14 to be supplied without leakage to the hydrogen generating unit of hydrogen generator 32. Opening 12 can be connected without any gaps to an inlet of an injection device (not shown) for injecting the hydrogen carrier into storage container 1.

[0044] The opening 12 is closed with a lid (not shown), for example, after the hydrogen carrier is stored in the storage container 1. The recess 18 has a depth such that even when the opening 12 is closed with a lid, the lid does not protrude from the recess 18. Therefore, even if a plurality of storage containers 1 are arranged side by side in the front-rear direction such that the flat surface portion 17 on which the recess 18 is formed and the flat surface portion 17 on which the recess 18 is not formed are in contact with or adjacent to each other, the opening 12 and the lid closing the opening 12 will not interfere with the opposing flat surface portion 17.

[0045] The recess 15 is formed in a part of at least one of the pair of flat surfaces 16. The recess 15 is formed so as to be recessed inward from the other part 16a of the flat surface 16, and at least a part of the recess 15 is formed to be connected to the outside of the flat surface 16 in the direction along the flat surface 16. In this embodiment, as shown in FIG. 3, the recess 15 is formed so as to be recessed all around the same place in the longitudinal direction of the storage container 1. That is, the recess 15 is formed in each of the pair of flat surfaces 16 in the up-down direction when the storage container 1 is installed, and the recess 15 is also formed in each of the pair of flat surfaces 16 in the left-right direction. These four recesses 15 are continuous all around the storage container 1.

[0046] The recess 15 may be formed in at least one of the flat surfaces 16. For example, when the recess 15 is formed in the upper flat surface 16 in the installed state, the right or left side, or the front or rear side of the recess 15 may be connected to the outside. However, it is preferable that the recess 15 is connected to the outside on both sides in the left-right direction or both sides in the front-back direction. Note that a part of the recess 15 is connected to the outside means that even if a part of the recess 15 is opened and the side facing the bottom surface of the recess 15 is blocked, gas can pass between the inside and the outside of the recess 15. For example, when the recess 15 is formed on the upper side of the storage container 1 and the left-right direction of the recess 15 is connected to the outside, gas can flow between the inside and the outside of the recess 15 in the left-right direction even if the upper side of the recess 15 is blocked.

[0047] The recesses 15 are preferably formed in at least two of the plurality of flat surfaces 16. For example, the recesses 15 may be formed in each of the pair of flat surfaces 16 described above. Alternatively, when a pair of flat surfaces 16 is provided on the outer wall surface of the storage container 1 in at least two directions among the up-down direction, the left-right direction, and the front-rear direction in the installed state of the storage container 1, the recesses 15 may be formed in at least two of these flat surfaces 16. For example, the recesses 15 may be formed in the upper flat surface 16 and the right or left flat surface 16.

[0048] However, as described below, in order to efficiently discharge hydrogen gas discharged from relief valve 11 to the outside, it is preferable that recesses 15 are formed in each of a pair of flat surfaces 16 on both sides in the vertical direction and a pair of flat surfaces 16 on both sides in the horizontal direction. This allows the space formed by the opposing recesses 15 between adjacent storage containers 1 to communicate with the outside of the area in which the storage containers 1 are arranged, regardless of how the storage containers 1 are arranged.

[0049] The relief valve 11 is provided inside the recess 15 (inside the recess), and automatically opens when the pressure inside the storage unit 14 exceeds a predetermined value, thereby releasing the gas inside the storage unit 14 to the outside. It is sufficient that the relief valve 11 is provided in at least one recess 15 out of the multiple recesses 15. As shown in FIG. 2, the relief valve 11 is formed on the bottom surface 15a of the recess 15, and is provided so as to close the communication port 15b that communicates with the storage unit 14. That is, the relief valve 11 is provided on the bottom surface 15a of the recess 15.

[0050] The recess 15 has a depth such that the relief valve 11 installed inside does not protrude outside the recess 15. Therefore, even if the storage containers 1 are stacked vertically or lined up horizontally or front-to-back with the flat surfaces 16 on which the recesses 15 are formed abutting or adjacent to each other, the relief valve 11 does not interfere with a part of the adjacent storage container 1. Furthermore, the opening and closing operation of the relief valve 11 is not hindered.

[0051] As described above, there is a risk that the hydrogen carrier in the storage container 1 may react with a liquid containing water for some reason, generating hydrogen gas. This hydrogen gas may then fill the storage section 14, causing the storage container 1 to be unable to withstand the pressure of the expanding hydrogen gas and burst. In such a case, the relief valve 11 automatically opens due to the pressure, releasing the excess hydrogen gas to the outside, thereby preventing damage to the storage container 1.

[0052] In addition, the above-mentioned filter 13 is provided at the communication port 15b between the relief valve 11 and the storage unit 14. The filter 13 is configured to allow hydrogen gas to pass through but not the hydrogen carrier in the storage unit 14. This makes it possible to prevent the hydrogen carrier from leaking to the outside through the communication port 15b during transportation of the storage container 1, and also makes it possible to discharge part of the hydrogen gas to the outside through the filter 13 and relief valve 11 provided at the communication port 15b when the pressure of the hydrogen gas in the storage unit 14 increases.

[0053] The relief valve 11 may be provided in at least one of the recesses 15 formed on the four faces perpendicular to the longitudinal direction of the storage container 1, but a plurality of recesses 15 may be provided in the other faces. Furthermore, a recess may be formed in either one or both of the flat surfaces 17 on both sides in the front-rear direction of the storage container 1, and the relief valve 11 may be provided in this recess. For example, the relief valve 11 may be provided in the recess 18 in which the above-mentioned opening 12 is formed.

[0054] In this embodiment, one relief valve 11 is provided in one recess 15, but it is preferable to provide a relief valve 11 in each of two or more recesses 15. For example, when a recess 15 is formed in each of a pair of flat surfaces 16 on both sides in the up-down or left-right direction in the installed state, a relief valve 11 may be provided in each of the multiple recesses 15.

[0055] Alternatively, when a pair of flat surfaces 16 are provided on the outer wall surface of the storage container 1 in at least two directions among the up-down direction, the left-right direction, and the front-rear direction in the installed state of the storage container 1, and the recesses 15 are formed in at least two of the flat surfaces 16, it is preferable that the relief valves 11 are provided in each of the recesses 15. That is, the relief valves 11 may be provided in each of the recesses 15 formed in the pair of flat surfaces 16 on both sides in any of the up-down direction, the left-right direction, and the front-rear direction, or may be provided in each of the recesses 15 formed in the flat surfaces 16 regardless of the direction. For example, one relief valve 11 may be provided on the upper side and one on the right or left side in the installed state.

[0056] Furthermore, when a pair of flat surfaces 16 are provided on the outer wall surface of the storage container 1 in the up-down and left-right directions when the storage container 1 is in an installed state, and recesses 15 are formed in each of all of the flat surfaces 16, it is preferable to provide relief valves 11 in each of the recesses 15. In this case, relief valves 11 are provided in all of the recesses 15 on the upper, lower, right, and left sides when the storage container 1 is in an installed state.

[0057] Note that since relief valve 11 automatically opens when the pressure inside storage container 1 exceeds a predetermined value, at least one relief valve 11 is sufficient, but from the viewpoint of more reliably discharging hydrogen gas from relief valve 11, it is preferable to provide relief valve 11 in each of the recesses 15 of the multiple flat surface portions 16 as described above. For example, if relief valve 11 is located on the lower side in the installed state, hydrogen gas may not be easily discharged from the lower relief valve 11 because the specific gravity of hydrogen gas is smaller than that of air. In this case, if other relief valves 11 are provided on the upper, right, left, etc. in the installed state, hydrogen gas can be efficiently discharged from these relief valves 11.

[0058] From the viewpoint of efficiently discharging hydrogen gas, the relief valve 11 is preferably located on the upper side when the storage container 1 is installed. For this reason, by providing the relief valve 11 on any of the upper, lower, right and left sides as described above, any of the relief valves 11 can be located on the upper side when installing the storage container 1 without having to consider the orientation of the storage container 1.

[0059] [Storage of storage containers] The storage state of the above-mentioned storage container 1 will be described with reference to Fig. 4 and Fig. 5. Fig. 4 and Fig. 5 each show an example of a storage state in which a plurality of storage containers 1 are arranged side by side. The storage container 1 shown in Fig. 4 and Fig. 5 has recesses 15 formed so as to be continuous with each other in four directions, namely, the up-down direction and the left-right direction, in the installed state, and all around the circumference. Also, a relief valve 11 is provided in the upper recess 15 in the installed state.

[0060] 4 shows a case where multiple storage containers 1 are stacked vertically and arranged side by side in the front-to-rear direction. Since the opening 12 of the storage container 1 is formed to fit within the recess 18, the storage containers 1 can be arranged with no gaps in the front-to-rear direction so that the flat surfaces 17 of the storage containers 1 arranged side by side in the front-to-rear direction abut against each other.

[0061] Meanwhile, in terms of the vertical direction of the storage containers 1, multiple storage containers 1 can be stacked vertically with no gaps so that the upper flat surface 16 of the lower storage container 1 abuts the lower flat surface 16 of the upper storage container 1. At this time, the recess 15 formed in the upper flat surface 16 of the lower storage container 1 faces the recess 15 formed in the lower flat surface 16 of the upper storage container 1, and a space penetrating in the left-right direction is formed between these two recesses 15. A relief valve 11 is provided in the recess 15 of the lower storage container 1, and hydrogen gas discharged from the relief valve 11 is discharged through this space to the outside of the area where multiple storage containers 1 are stacked.

[0062] FIG. 5 shows a case where a plurality of storage containers 1 are stacked vertically and arranged side by side. The relationship of each part when the storage containers 1 are stacked vertically is as described in FIG. 4. On the other hand, in the horizontal direction of the storage containers 1, the plurality of storage containers 1 can be arranged with no gaps on the left and right sides so that the left flat surface 16 of the storage container 1 on the right side abuts the right flat surface 16 of the storage container 1 on the left side. At this time, the recess 15 formed on the left flat surface 16 of the storage container 1 on the right side faces the recess 15 formed on the right flat surface 16 of the storage container 1 on the left side, and a space penetrating in the vertical direction is formed between these two recesses 15. Therefore, the hydrogen gas discharged from the relief valve 11 of the lower storage container 1 is discharged to the outside of the area where the plurality of storage containers 1 are stacked and laid out in the horizontal direction through the horizontal space formed between a pair of recesses 15 facing each other vertically and the vertical space formed between a pair of recesses 15 facing each other horizontally.

[0063] In this embodiment, the recesses 15 are formed in the flat surfaces 16 that are in contact with or adjacent to each other when multiple storage containers 1 are stacked or arranged side by side, and the relief valves 11 are provided in the recesses 15. The recesses 15 are formed so that at least a portion of the recesses 15 communicates with the outside of the flat surface 16 in the direction along the flat surface 16. Therefore, the hydrogen gas discharged from the relief valves 11 is easily discharged to the outside from the portion communicating the recesses 15 with the outside. Therefore, even if the storage containers 1 are stored by stacking them vertically or laying them out horizontally or front to back, the increase in pressure inside the storage containers 1 can be suppressed. In addition, the hydrogen gas discharged from the relief valves 11 can be prevented from accumulating between the multiple storage containers 1, improving the safety of the storage location.

[0064] [Another example of the first embodiment] Another example of the first embodiment will be described with reference to Figs. 6(a) and (b). In the above example, a configuration in which a plurality of storage containers 1 are simply stacked or lined up has been described. In contrast, this example is provided with a fitting portion 40 that fits together a plurality of stacked or lined up storage containers 1A, 1B. The fitting portion 40 is provided on the flat surface portion 16, and can be fitted into the fitting portion 40 provided on the other storage container 1B when the storage container 1A is placed so that the flat surface portions 16 of the storage container 1A and the other storage container 1B face each other.

[0065] In this embodiment, the fitting portion 40 has a protruding portion 41 protruding from the flat surface portion 16 and a bent portion 42 bent from the protruding portion 41 in a direction substantially parallel to the flat surface portion 16. Such fitting portions 40 may be provided on both flat surface portions 16 in the up-down direction in the installed state, on both flat surface portions 16 in the left-right direction, or on all flat surface portions 16 in the up-down direction and the left-right direction. In the front-rear direction, the fitting portion 40 may be provided on the flat surface portion 17 by, for example, making the recess 18 on the side where the opening 12 is formed smaller, or by providing the opening 12 on another surface. In this example, a plurality of fitting portions 40 (three in the illustrated example) are provided on all flat surface portions 16 in the up-down direction and the left-right direction.

[0066] When stacking the storage containers 1A, 1B, as shown in FIG. 6(a), the fitting portions 40 are shifted from each other in the front-rear direction. Then, as shown in FIG. 6(b), one of the storage containers 1A, 1B is shifted from the other in the front-rear direction to fit the fitting portions 40 together. At this time, the bent portions 42 of the storage containers 1A, 1B overlap each other vertically, so that the storage containers 1A, 1B can be prevented from being separated in the vertical direction. In addition, the tip of the bent portion 42 of one container faces the protruding portion 41 of the other container, so that the storage containers 1A, 1B can be prevented from being shifted in the front-rear direction.

[0067] The same applies when the storage containers 1A, 1B are arranged side by side in the left-right direction; since the bent portions 42 overlap with each other in the left-right direction, the storage containers 1A, 1B can be prevented from being separated in the left-right direction.

[0068] The storage containers 1A, 1B can be fixed to each other by providing the fitting portion 40 in this manner. This makes it possible to prevent the storage containers 1A, 1B from collapsing due to vibration or being inadvertently displaced due to the action of external force when they are stacked or lined up for transport or storage.

[0069] <Second embodiment> The second embodiment will be described with reference to Figures 7 and 8. In the above-mentioned first embodiment, a storage container 1 for storing a hydrogen carrier was described. In contrast, in this embodiment, a storage container 1C is configured to be able to store by-products as well. Since other configurations and functions are similar to those of the above-mentioned first embodiment, the same reference numerals are used for similar configurations, and descriptions thereof will be omitted or simplified. The following description will focus on the points that are different from the first embodiment.

[0070] This embodiment is an example of a case where the container is used not only to deliver and supply the raw material (hydrogen carrier) to the hydrogen generation apparatus 32, but also as a collection container for the by-product after the hydrogen generation reaction in the hydrogen generation apparatus 32 (when the hydrogen carrier is sodium borohydride, the by-product is sodium metaborate).

[0071] FIG. 7 is a block diagram showing a schematic configuration of the hydrogen generation system 100A of this embodiment. The hydrogen generation system 100A includes a storage container 1C for hydrogen carriers and by-products, a hydrogen generation device 32, a water supply unit 33, and a fuel cell system 35. The configuration other than the storage container 1C is the same as that shown in FIG. 1. In the hydrogen generation system 100A of this embodiment, as in the configuration of FIG. 1, the hydrogen carrier is first injected into the storage container 1C, and if hydrogen is not generated, or if hydrogen is generated but does not exceed a threshold value set in consideration of safety, it is delivered directly to the hydrogen generation device 32. Then, the hydrogen carrier is supplied from the storage container 1C and a liquid containing water is supplied from the water supply unit 33 to the hydrogen generation device 32, where hydrogen gas and by-products are generated.

[0072] When the hydrogen generation reaction in hydrogen generator 32 is complete and storage container 1C is used as a by-product collection container, if no hydrogen is generated from the collected by-product, or if hydrogen is generated but does not exceed a threshold value set for safety reasons, it is collected directly into storage container 1C. If hydrogen is generated from the by-product for some reason and the air pressure inside storage container 1C exceeds a predetermined value, hydrogen gas relief valve 11 automatically opens and the excess hydrogen is released outside the container.

[0073] The configuration of such a storage container 1C will be described with reference to FIG. 8. The storage container 1C has a first storage section 14A and a second storage section 23. The first storage section 14A is a section for storing a hydrogen carrier, and the second storage section 23 is a section for storing a by-product generated together with hydrogen when the hydrogen carrier is reacted with a liquid containing water. The second storage section 23 does not allow the by-product to pass through to the first storage section 14A, but allows the gas generated in the second storage section 23 to pass through to the first storage section 14A. In this embodiment, the second storage section 23 is an elastic bag-like member, and is disposed inside the first storage section 14A. The material of the second storage section 23 may be fiber or rubber.

[0074] The storage container 1C is provided with a flat surface portion 16, a recessed portion 15, a relief valve 11, and the like, as in the first embodiment described above. A recessed portion 18 is formed in the flat surface portion 17 on one side in the front-rear direction, and an opening portion 12 is formed for injecting or discharging the hydrogen carrier into or from the first storage portion 14A. On the other hand, a flat surface portion 20 is provided as a third flat surface portion on the other side in the front-rear direction. The flat surface portion 20 is provided at a position different from the flat surface portion 16 as the first flat surface portion on the outer wall surface of the storage container 1C, and in this embodiment, the flat surface portion 20 is provided on the surface opposite to the side on which the opening portion 12 is formed. The flat surface portion 20 abuts or is adjacent to the flat surface portion 17 when the storage containers 1C are arranged in the front-rear direction.

[0075] A recess 24 is formed as a third recess in a portion of the flat portion 20 so as to be recessed inward more than the other portions. An opening 21 is formed in the recess 24 as a by-product opening that communicates the inside and outside of the second storage portion 23 and injects or discharges by-products into or from the second storage portion 23. The opening 21 is formed to fit within the recess 24. The opening 21 can be connected to a by-product discharge port of the hydrogen generation device 32 without any gaps, and is configured to be able to recover by-products from the hydrogen generation device 32 without any leaks. The opening 21 is also configured to be connected to a recovery port of a recovery device (not shown) for recovering by-products in the second storage portion 23 without any gaps.

[0076] The second storage section 23, which is in the form of a bag having elasticity, is connected to the opening 21, and the by-products collected through the opening 21 are sent to the second storage section 23. The second storage section 23 expands due to its elasticity in accordance with the volume of the collected by-products. Furthermore, when the by-products in the second storage section 23 are collected by a collection device (not shown), the second storage section 23 shrinks due to its elasticity.

[0077] The by-products collected in the second storage section 23 are by-products resulting from the reaction in the hydrogen generating device 32, and may contain moisture or may contain unreacted residual hydrogen carriers. This may result in the generation of residual hydrogen gas in the second storage section 23. For this reason, the second storage section 23 is designed to have a bag-like elasticity and to be impermeable to only hydrogen gas, even if hydrogen gas is generated from the by-products, while being impermeable to the by-products themselves. The hydrogen gas that has permeated from the second storage section 23 to the first storage section 14A is discharged to the outside through the relief valve 11.

[0078] In the case of this embodiment, even if the storage container 1C is used to store by-products, the hydrogen gas generated inside can be discharged from the relief valve 11. As in the first embodiment, even if the storage containers 1C are stored by stacking them vertically or lining them up in the left-right or front-back directions, the increase in pressure inside the storage container 1C can be suppressed. In addition, the hydrogen gas discharged from the relief valve 11 can be prevented from accumulating between multiple storage containers 1C, improving the safety of the storage location. The storage container 1C of this embodiment may also be provided with the fitting portion 40 described in Figs. 6(a) and (b).

[0079] <Other embodiments> In the above-mentioned first embodiment, the storage container 1 for the hydrogen carrier has been described. However, by-products may be stored in the storage container 1. That is, the storage container 1 for the hydrogen carrier may be used as a storage container for the by-products. In this case, the by-products are stored in the storage section 14 of the storage container 1.

[0080] The disclosure of this embodiment also includes the following configuration. (Configuration 1) A hydrogen carrier storage container capable of storing a hydrogen carrier, a storage section for storing a hydrogen carrier; A pair of flat surfaces are provided on both sides of the outer wall surface of the storage container in at least one of the up-down direction, the left-right direction, and the front-rear direction when the storage container is installed; a recess formed in a portion of at least one of the pair of planar portions, the recess being recessed inwardly relative to other portions of the planar portion and at least a portion of the recess being formed so as to communicate with the outside of the planar portion in a direction along the planar portion; a relief valve provided in the recess and automatically opening when the pressure inside the storage unit exceeds a predetermined value to release the gas inside the storage unit to the outside. A storage container for a hydrogen carrier. (Configuration 2) The recesses are formed in the pair of flat surfaces. A storage container for a hydrogen carrier according to configuration 1. (Configuration 3) The pair of planar portions are provided on the outer wall surface of the storage container in at least two directions among the up-down direction, the left-right direction, and the front-rear direction when the storage container is installed, The recesses are formed in at least two of the flat surfaces. 3. A storage container for a hydrogen carrier according to configuration 1 or 2. (Configuration 4) The relief valve is provided in each of the recesses. 4. A storage container for a hydrogen carrier according to configuration 2 or 3. (Configuration 5) The pair of planar portions are provided on the outer wall surface of the storage container in the up-down direction and the left-right direction when the storage container is installed, The recesses are formed in each of the planar portions. A storage container for a hydrogen carrier according to configuration 1. (Configuration 6) The relief valve is provided in each of the recesses. A storage container for a hydrogen carrier according to configuration 5. (Configuration 7) The storage unit further includes an opening for injecting a hydrogen carrier into the storage unit or discharging the hydrogen carrier from the storage unit, the opening communicating the inside and the outside of the storage unit. 7. A storage container for a hydrogen carrier according to any one of configurations 1 to 6. (Configuration 8) the recess is a first recess, the planar portion in which the first recess is formed is a first planar portion, A second flat surface provided at a position different from the first flat surface on the outer wall surface of the storage container; A second recess is formed in a part of the second flat surface portion so as to be recessed inwardly relative to other parts of the second flat surface portion, The opening is provided in the second recess. A storage container for a hydrogen carrier according to configuration 7. (Configuration 9) The storage container further includes a fitting portion provided on the flat surface portion, the fitting portion being capable of fitting with the fitting portion provided on the other storage container when the storage container and the other storage container are installed such that their flat surfaces face each other. 9. A storage container for a hydrogen carrier according to any one of configurations 1 to 8. (Configuration 10) The fitting portion has a protruding portion protruding from the flat portion and a bent portion bent from the protruding portion in a direction substantially parallel to the flat portion. A storage container for a hydrogen carrier according to configuration 9. (Configuration 11) The storage container has a cylindrical shape with a polygonal cross section perpendicular to the longitudinal direction. 11. A storage container for a hydrogen carrier according to any one of configurations 1 to 10. (Configuration 12) the reservoir is a first reservoir, a second storage unit for storing a by-product generated together with hydrogen when the hydrogen carrier is reacted with the water-containing liquid; The second storage section does not allow by-products to permeate into the first storage section, but allows gas generated in the second storage section to permeate into the first storage section. 12. A storage container for a hydrogen carrier according to any one of configurations 1 to 11. (Configuration 13) the recess is a first recess, the planar portion in which the first recess is formed is a first planar portion, A third flat portion provided at a position different from the first flat portion on the outer wall surface of the storage container; a third recess formed in a part of the third flat surface portion so as to be recessed inwardly relative to other parts of the third flat surface portion; a by-product opening that communicates the inside and the outside of the second storage unit and is used to inject a by-product into the second storage unit or discharge a by-product from the second storage unit; The by-product opening is provided in the third recess. 13. A storage container for a hydrogen carrier according to claim 12. (Configuration 14) A by-product storage container capable of storing a by-product generated together with hydrogen when a hydrogen carrier is reacted with a liquid containing water, a storage section for storing the by-product; A pair of flat surfaces are provided on both sides of the outer wall surface of the storage container in at least one of the up-down direction, the left-right direction, and the front-rear direction when the storage container is installed; a recess formed in a portion of at least one of the pair of planar portions, the recess being recessed inwardly relative to other portions of the planar portion and at least a portion of the recess being formed so as to communicate with the outside of the planar portion in a direction along the planar portion; a relief valve provided in the recess and automatically opening when the pressure inside the storage unit exceeds a predetermined value to release the gas inside the storage unit to the outside. A by-product storage container comprising: [Explanation of symbols]

[0081] 1, 1A, 1B, 1C... Storage vessels (hydrogen carrier storage vessels, by-product storage vessels) 11. Relief valve 12 Opening 14... Storage section 14A...First storage unit 15 Recess (first recess) 16...Plane part (first plane part) 16a...Other parts 17...Plane part (second plane part) 18 Recess (second recess) 20...Plane part (3rd plane part) 21...Opening (by-product opening) 23...Second storage section 24 Recess (third recess) 40... Fitting part 41...Protrusion 42...Bending section

Claims

1. A hydrogen carrier storage container capable of storing a hydrogen carrier, a storage section for storing a hydrogen carrier; A pair of flat surfaces are provided on both sides of the outer wall surface of the storage container in at least one of the up-down direction, the left-right direction, and the front-rear direction when the storage container is installed; a recess formed in a portion of at least one of the pair of planar portions, the recess being recessed inwardly relative to other portions of the planar portion and at least a portion of the recess being formed so as to communicate with the outside of the planar portion in a direction along the planar portion; a relief valve provided in the recess and automatically opening when the pressure inside the storage unit exceeds a predetermined value to release the gas inside the storage unit to the outside. A storage container for a hydrogen carrier.

2. The recesses are formed in the pair of flat surfaces.

2. The hydrogen carrier storage container according to claim 1 .

3. The pair of planar portions are provided on the outer wall surface of the storage container in at least two directions among the up-down direction, the left-right direction, and the front-rear direction when the storage container is installed, The recesses are formed in at least two of the planar portions.

2. The hydrogen carrier storage container according to claim 1 .

4. The relief valve is provided in each of the recesses.

4. A storage container for a hydrogen carrier according to claim 2 or 3.

5. The pair of planar portions are provided on the outer wall surface of the storage container in the up-down direction and the left-right direction when the storage container is installed, The recesses are formed in each of the planar portions.

2. The hydrogen carrier storage container according to claim 1 .

6. The relief valve is provided in each of the recesses.

6. A hydrogen carrier storage container according to claim 5.

7. The storage unit further includes an opening for injecting a hydrogen carrier into the storage unit or discharging the hydrogen carrier from the storage unit, the opening communicating the inside and the outside of the storage unit.

2. The hydrogen carrier storage container according to claim 1 .

8. the recess is a first recess, the planar portion in which the first recess is formed is a first planar portion, A second flat surface portion is provided on an outer wall surface of the storage container at a position different from the first flat surface portion; a second recess formed in a part of the second flat surface portion so as to be recessed inwardly relative to other parts of the second flat surface portion, The opening is provided in the second recess.

8. A hydrogen carrier storage container according to claim 7.

9. The storage container further includes a fitting portion provided on the flat surface portion, the fitting portion being capable of fitting with the fitting portion provided on the other storage container when the storage container and the other storage container are installed such that their flat surfaces face each other.

2. The hydrogen carrier storage container according to claim 1 .

10. The fitting portion has a protruding portion protruding from the flat portion and a bent portion bent from the protruding portion in a direction substantially parallel to the flat portion.

10. The hydrogen carrier storage container according to claim 9.

11. The storage container has a cylindrical shape with a polygonal cross section perpendicular to the longitudinal direction.

2. The hydrogen carrier storage container according to claim 1 .

12. the reservoir is a first reservoir, a second storage unit for storing a by-product generated together with hydrogen when the hydrogen carrier is reacted with the water-containing liquid; The second storage section does not allow by-products to permeate into the first storage section, but allows gas generated in the second storage section to permeate into the first storage section.

2. The hydrogen carrier storage container according to claim 1 .

13. the recess is a first recess, the planar portion in which the first recess is formed is a first planar portion, A third flat portion is provided on an outer wall surface of the storage container at a position different from the first flat portion; a third recess formed in a part of the third flat surface portion so as to be recessed inwardly relative to other parts of the third flat surface portion; a by-product opening that communicates the inside and the outside of the second storage portion and is used to inject a by-product into the second storage portion or to discharge a by-product from the second storage portion; The by-product opening is provided in the third recess.

13. A hydrogen carrier storage vessel according to claim 12.

14. A by-product storage container capable of storing a by-product generated together with hydrogen when a hydrogen carrier is reacted with a liquid containing water, a storage section for storing the by-product; A pair of flat surfaces are provided on both sides of the outer wall surface of the storage container in at least one of the up-down direction, the left-right direction, and the front-rear direction when the storage container is installed; a recess formed in a portion of at least one of the pair of planar portions, the recess being recessed inwardly relative to other portions of the planar portion and at least a portion of the recess being formed so as to communicate with the outside of the planar portion in a direction along the planar portion; a relief valve provided in the recess, which automatically opens when the pressure inside the storage unit exceeds a predetermined value to release the gas inside the storage unit to the outside. A by-product storage container comprising:

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