Hydrogen generation device and reaction tank

Abstract

A hydrogen generation device includes a tank portion 201, a hydrogen carrier supply portion 110, a screw conveyor 202, a liquid supply portion, and a hydrogen collection portion. The hydrogen carrier supply unit (110) supplies a solid hydrogen carrier to the tank unit (201). A spiral conveyor 202 is provided in the tank part 201 and includes a spiral blade 202a for conveying the hydrogen carrier supplied from the hydrogen carrier supply part 110. The liquid supply unit supplies a liquid containing water to the hydrogen carrier conveyed by the spiral conveyor 202. The hydrogen collection part collects hydrogen generated by a reaction between the hydrogen carrier on the spiral conveyor 202 and the liquid. As a result, it is possible to obtain a hydrogen generation device that easily promotes a reaction between a hydrogen carrier and a water-containing liquid.

Description

Technical Field

[0001] The present invention relates to a hydrogen generation device that generates hydrogen by using a hydrogen carrier as a raw material. The hydrogen carrier has the property of generating hydrogen when an aqueous liquid is poured thereon, and also relates to a reaction case for reacting a liquid with the hydrogen carrier. Background Art

[0002] As a hydrogen generation device, a device has been proposed that supplies water and a solvent to sodium borohydride and generates hydrogen by hydrolysis of sodium borohydride (for example, Patent Document 1). Citation List Patent Document

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-114708 Summary of the Invention Technical Problem

[0004] Here, for a hydrogen generation device, a structure that can stably perform a hydrolysis reaction of a hydrogen carrier such as sodium borohydride is desired. The above Patent Document 1 only describes generating hydrogen by supplying sodium borohydride, water, and a solvent to a reaction part, and does not describe how to particularly promote the reaction of sodium borohydride in the reaction part.

[0005] An object of the present invention is to provide a hydrogen generation device that can easily promote the reaction between a hydrogen carrier and an aqueous liquid. Solution to the Problem

[0006] The hydrogen generation device of the present invention includes: a box part; a hydrogen carrier supply part configured to supply a solid hydrogen carrier to the box part; a screw conveyor provided in the box part and including screw blades for conveying the hydrogen carrier supplied by the hydrogen carrier supply part; a liquid supply part configured to supply a liquid containing water to the hydrogen carrier conveyed by the screw conveyor; and a hydrogen collection part configured to collect hydrogen generated by the reaction between the hydrogen carrier on the screw conveyor and the liquid.

[0007] In addition, the reaction case of the present invention is a reaction case configured to react a solid hydrogen carrier with an aqueous liquid to generate hydrogen, and the reaction case includes: a box part equipped with a first supply port for supplying the hydrogen carrier, a second supply port for supplying the liquid, and a collection port for collecting hydrogen generated by the reaction between the hydrogen carrier and the liquid; and a screw conveyor provided in the box part and including screw blades for conveying the hydrogen carrier supplied by the first supply port and reacting the conveyed hydrogen carrier with the liquid supplied from the second supply port. Effects of the Invention

[0008] According to the present invention, a hydrogen generation device can be provided that can easily promote the reaction between a hydrogen carrier and an aqueous liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a conceptual diagram of a hydrogen generation device according to an embodiment. Figure 2 is a schematic structural perspective view of a hydrogen generation unit according to the embodiment. Figure 3 is a schematic structural perspective view of a reaction tank according to a first different example of the embodiment. Figure 4 is a schematic structural perspective view of a reaction tank according to a second different example of the embodiment. Figure 5 is a schematic structural perspective view showing an initial state of a hydrogen carrier storage tank according to the embodiment. Figure 6 is a schematic structural perspective view showing a state in which the hydrogen carrier has been used up in the hydrogen carrier storage tank according to the embodiment. Figure 7 is a schematic diagram of a temperature control unit according to the embodiment. Figure 8 is a schematic structural perspective view of another example of the hydrogen generation unit according to the embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0010] Embodiments will be described below with reference to Figures 1 to 8 First, as an alternative energy source to fossil fuels, hydrogen is attracting attention. This is because, unlike fossil fuels, hydrogen does not produce, for example, carbon dioxide when burned, and carbon dioxide is a greenhouse gas that causes global warming. An example of a system that uses hydrogen as an energy source and is put into practical use is a fuel cell vehicle. A fuel cell vehicle is a vehicle that generates electricity by using hydrogen as a raw material and moves by driving an electric motor using the generated electricity. Most fuel cell vehicles store hydrogen, which serves as an energy source, in a hydrogen tank, and generate electricity by charging the hydrogen discharged from the hydrogen tank into a fuel cell. In the hydrogen tank, hydrogen is stored in a compressed state at a high pressure such as 70 MPa (up to 700 times the atmospheric pressure).

[0011] The problem with using hydrogen as an energy source is its low energy density. The volumetric energy density of hydrogen is about 1 / 3000 of that of gasoline, and even when using a 70 MPa hydrogen tank, only about 1 / 5 of the energy of the same volume of gasoline can be obtained. Therefore, typically, a fuel cell vehicle including a hydrogen tank needs to be refueled more frequently than a gasoline-powered vehicle.

[0012] Therefore, as materials that can carry hydrogen with a higher energy density than hydrogen tanks (i.e., hydrogen carriers), various materials have been considered. For example, ammonia, methylcyclohexane, etc. are known as hydrogen carriers, and during use, the hydrogen carrier rather than hydrogen itself is transported and hydrogen is extracted from the hydrogen carrier.

[0013] Among these hydrogen carrier materials, metal hydrides such as sodium borohydride are well-known, and hydrogen can be easily extracted from them by pouring water thereon. As a method for obtaining hydrogen by hydrolysis of sodium borohydride, a method of dissolving sodium borohydride in water and using it as an aqueous solution is known. However, in the case of this method, there is a problem that the amount of water required is more than the amount required in theory represented by the reaction formula, thereby reducing the substantial volume energy density.

[0014] Therefore, in the present embodiment, hydrogen is generated by pouring an aqueous liquid onto a solid hydrogen carrier by a hydrogen generation device configured as described below. In addition, by-products generated from the reaction between the hydrogen carrier and the liquid are collected. The by-products can be restored to the hydrogen carrier. [Hydrogen Generation Device]

[0015] The schematic configuration of the hydrogen generation device 1 will be described by using Figure 1 The hydrogen generation device 300 of the present embodiment includes: a liquid supply unit 301, a hydrogen generation unit 302, a liquid collection unit 303, a hydrogen collection unit 304, and a temperature adjustment unit 305. The liquid supply unit 301 is a part that supplies an aqueous liquid to the hydrogen generation unit 302 and is constituted by a tank or the like. The liquid collection unit 303 collects the aqueous liquid output from the hydrogen generation unit 302, removes foreign matters through a filter, and returns the liquid to the liquid supply unit 301. The hydrogen collection unit 304 removes water vapor from the gas discharged from the hydrogen generation unit 302302 by using silica gel or the like so that only hydrogen remains, and supplies the hydrogen to the outside of the device. The temperature adjustment unit 305 adjusts the temperature of the hydrogen generation unit 302 by, for example, flowing cooling water in the hydrogen generation unit 302. As will be described in detail later, the hydrogen generation unit 302 is a part that generates hydrogen by reacting a solid hydrogen carrier with an aqueous liquid. First, the hydrogen carrier and the aqueous liquid will be described. [Hydrogen Carrier]

[0016] The "hydrogen carrier" mentioned in the present embodiment is not particularly limited as long as it is a solid hydrogen carrier that generates hydrogen when an aqueous liquid is poured thereon. For example, the following substances can be used alone or in combination: 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. In addition, additives such as reaction promoters or desiccants can be contained.

[0017] In addition, the hydrogen carrier of the present embodiment is preferably a solid such as powder or granules, but sheets, pellets, and pastes can also be used. As the powder, powders with a particle size of about 10 μm or more and 10 mm or less, powders with a particle size of 10 μm or more and 3 mm or less, and powders with a particle size of 10 μm or more and 100 μm or less are more preferred. In addition, in the case of using in the form of a sheet or pellet, from the viewpoint of improving the reactivity with the aqueous liquid, surface roughening, pore-forming treatment, etc. are preferably performed to increase the surface area and the contact area with the aqueous liquid.

[0018] In the present embodiment, sodium borohydride powder with an average particle size of 50 μm is used as the solid hydrogen carrier. It should be noted that the average particle size of the solid hydrogen carrier is not limited to this. The sodium borohydride powder reacts with water to generate hydrogen. After the reaction, the sodium borohydride is converted into sodium metaborate powder, which is a by-product. This reaction is represented by the following chemical formula. NaBH4 (sodium borohydride) + 2H2O (water) → NaBO2 (sodium metaborate) + 4H2 (hydrogen)... (1)

[0019] It is known that this reaction (chemical formula (1)) is promoted by a Raney catalyst, which is formed by a metal such as nickel, cobalt, or copper and an acidic solution such as citric acid or acetic acid. That is, the hydrogen carrier does not have to be composed of a single substance and can contain substances with different functions, such as a catalyst. For example, the hydrogen carrier can be composed of a mixture of sodium borohydride powder serving as a hydrogen generation source and Raney nickel powder serving as a catalyst. In this case, sodium borohydride reacts with the liquid to generate hydrogen, and Raney nickel does not change before and after the reaction. [Aqueous liquid]

[0020] The "aqueous liquid" mentioned in the present embodiment is not particularly limited as long as the liquid reacts with the hydrogen carrier to generate hydrogen when poured. That is to say, the aqueous liquid can be simple water. In addition, two or more kinds of aqueous liquids can be prepared. By preparing two or more kinds of aqueous liquids, the hydrogen generation rate can be adjusted.

[0021] The aqueous liquid can include water-soluble organic solvents. Examples thereof can include alcohols, polyalkylene glycols, glycol ethers, nitrogen-containing compounds, and sulfur-containing compounds. Two or more selected from these can also be used in combination. By containing water-soluble organic solvents, the surface tension, boiling point, and melting point of the aqueous liquid can be adjusted to optimize the reaction with the hydrogen carrier.

[0022] A surfactant can be added to the aqueous liquid. By using a surfactant, the surface tension of the aqueous liquid can be reduced, the contact area with the hydrogen carrier can be increased, and thus an effective reaction can be carried out.

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

[0024] The aqueous liquid may include a water-soluble basic substance. This basic substance acts as a negative catalyst in the reaction between the aqueous liquid and the hydrogen carrier. By adjusting the amount of the liquid containing the basic substance, the rate of hydrogen generation can be adjusted. In particular, by setting the pH value obtained from the aqueous liquid and the hydrogen carrier to be equal to or higher than 9.0, the hydrogen generation rate can be decreased. Examples thereof include alkalis such as sodium hydroxide, potassium hydroxide, and ammonia water, but are not limited thereto.

[0025] The aqueous liquid may include a buffer solution. The role of the buffer solution is to inhibit the pH fluctuation in the reaction between the aqueous liquid and the hydrogen carrier. By adjusting the amount of the liquid containing the buffer solution, the rate of hydrogen generation can be adjusted. Examples thereof include various buffer solutions such as phosphate buffer solution, glycine buffer solution, Good’s buffer liquid, Tris buffer solution, and ammonia buffer solution, but are not limited thereto.

[0026] In addition to the above components, if necessary, the aqueous liquid may further contain various additives such as defoaming agents, pH adjusters, viscosity adjusters, rust inhibitors, preservatives, antifungal agents, antioxidants, and anti-reducing agents. [Hydrogen generation section]

[0027] Next, the hydrogen generation section 302 of the present embodiment will be described by using Figures 2 to 7 The hydrogen generation section 302 includes a hydrogen carrier storage tank 101, a reaction tank 200, etc. In addition, hydrogen is generated in the reaction tank 200 by supplying a solid hydrogen carrier from the hydrogen carrier storage tank 101 to the reaction tank 200 and supplying an aqueous liquid from the liquid supply section 301 to the reaction tank 200. Details will be described below.

[0028] As Figure 2As shown, the hydrogen generation unit 302 includes a hydrogen carrier storage tank 101 serving as a cartridge, a hydrogen carrier supply unit 110, a reaction tank 200, and a by-product collection unit 210. The reaction tank 200 is a tank for generating hydrogen by reacting a solid hydrogen carrier with an aqueous liquid, and includes a tank portion 201 and a screw conveyor 202. In addition, as will be described in detail later, the reaction tank 200 generates hydrogen by reacting the hydrogen carrier on the screw conveyor 202 with an aqueous liquid while the screw conveyor 202 conveys the hydrogen carrier in the tank portion 201. Further, in the reaction tank 200, the by-products generated by the reaction are conveyed to the screw conveyor 202 as they are.

[0029] The hydrogen carrier storage tank 101 includes a hydrogen carrier storage portion 101a, a by-product accumulation portion 101b, and a separation membrane 102 serving as a separating member. The hydrogen carrier storage portion 101a is a portion for storing the hydrogen carrier to be supplied to the tank portion 201 through the hydrogen carrier supply unit 110. The by-product accumulation portion 101b is a portion for accumulating the by-products collected by the by-product collection unit 210. The separation membrane 102 separates the hydrogen carrier storage portion 101a and the by-product accumulation portion 101b from each other. The hydrogen carrier storage tank 101 can be attached to and detached from the tank portion 201. That is, the hydrogen carrier storage tank 101 is a replaceable cartridge.

[0030] The hydrogen carrier supply unit 110 is a portion for supplying a solid hydrogen carrier to the tank portion 201. The hydrogen carrier supply unit 110 connects the hydrogen carrier storage portion 101a of the hydrogen carrier storage tank 101 and the tank portion 201 to each other, and supplies the hydrogen carrier storage portion 101a to the tank portion 201.

[0031] The by-product collection unit 210 is a portion for collecting the by-products generated by the reaction between the hydrogen carrier and the liquid on the screw conveyor 202 and conveyed by the screw conveyor 202. The by-product collection unit 210 connects the by-product accumulation portion 101b of the hydrogen carrier storage tank 101 and the tank portion 201 to each other, and supplies the hydrogen carrier from the tank portion 201 to the by-product accumulation portion 101b. Each element will be described in detail below. [Reaction Tank]

[0032] The reaction tank 200 includes the tank portion 201 and the screw conveyor 202 as described above. The tank portion 201 is formed in a substantially cylindrical shape, and is provided with a first supply port 201a for supplying a hydrogen carrier, a second supply port 204 for supplying an aqueous liquid, and a first collection port 206 for collecting hydrogen generated by the reaction between the hydrogen carrier and the liquid.

[0033] In the present embodiment, as Figure 2As shown, the box portion 201 is arranged such that the central axis of the cylinder is in the vertical direction, and a first supply port (hydrogen supply port) 201a through which the hydrogen carrier is supplied is formed at the lower end side portion in the vertical direction. In addition, a first collection port 206 for collecting hydrogen generated in the box portion 201 is formed in the upper end surface of the box portion 201. The first collection port (hydrogen collection port) 206 corresponds to a first connection port connected to the hydrogen collection portion 304. The first collection port 206 is equipped with a gas-permeable lid 206a having gas permeability to allow gas to pass through it but not allow solids (powders in this embodiment) to pass through it. The gas-permeable lid 206a is formed of, for example, porous ceramics, and the hydrogen gas generated in the box portion 201 is supplied to the hydrogen collection portion 304 through the gas-permeable lid 206a.

[0034] In addition, in this embodiment, a plurality of second supply ports (liquid supply ports) 204 arranged in the vertical direction are formed in the side surface of the box portion 201. The second supply ports 204 are connected to the liquid supply portion 301 and supply the liquid supplied from the liquid supply portion 301 into the box portion 201. In Figure 2 the configuration shown, the second supply ports 204 are formed by a plurality of ports opening in the outer wall of the box portion 201, but this configuration is not limited thereto, and the second supply ports 204 can be configured in any form as long as the form allows the liquid to be supplied into the box portion 201.

[0035] For example, as Figure 3 a first different example shown in, the rotary shaft 202b of the screw conveyor 202 may have the second supply ports 204. In Figure 3 this case, the liquid supply portion 301 is connected to the inside of the rotary shaft 202b, and a plurality of second supply ports 204 are formed in the outer peripheral surface of the rotary shaft 202b. In addition, as in Figure 4 a second different example shown in, one second supply port 204 may be provided in the upper portion of the box portion 201.

[0036] In addition, in the box portion 201, a second collection port 201b for collecting by-products generated from the reaction between the hydrogen carrier and the liquid is formed. The second collection port (by-product collection port) 201b is formed at the upper end side portion in the vertical direction. In addition, a discharge port 207 for discharging the liquid remaining without being used for the reaction is formed in the box portion 201. The discharge port (liquid discharge port) 207 corresponds to a second connection port connected to the liquid collection portion 303, and the liquid discharged from the discharge port 207 is collected by the liquid collection portion 303. The discharge port 207 is formed to open in the lower end surface of the box portion 201.

[0037] The liquid supplied from the first supply port 204 to the tank portion 201 flows downward from the upper side to the lower side on the screw conveyor 202, and the reaction of the above chemical formula (1) is caused during this process. In this reaction, sodium metaborate and hydrogen gas are generated, and the liquid volume that remains without being used for the reaction accumulates in the lower part of the tank portion 201. Therefore, the discharge port 207 is formed in the lower part of the tank portion 201. The discharge port 207 is equipped with a liquid-permeable lid 207a having liquid permeability, allowing the liquid to pass through it while not allowing solids to pass through. The liquid-permeable lid 207a is made of, for example, porous ceramics, and the liquid accumulated in the lower part of the tank portion 201 is gradually supplied to the liquid collection portion 303 through the liquid-permeable lid 207a. The liquid collected by the liquid collection portion 303 is sent to the liquid supply portion 301 as described above and is supplied again to the tank portion 201 through the second supply port 204.

[0038] The screw conveyor 202 is provided in the tank portion and includes screw blades 202a for conveying hydrogen supplied from the first supply port 201a and causing the conveyed hydrogen carrier to react with the liquid supplied from the second supply port 204. That is, the screw conveyor 202 includes a rotating shaft 202b and blades 202a provided in a spiral shape around the rotating shaft 202b. In the present embodiment, the screw conveyor 202 is arranged such that the rotating shaft 202b is substantially parallel to the vertical direction and is configured to convey the hydrogen carrier from the lower side to the upper side.

[0039] The rotating shaft 202b is provided on the central axis of the cylindrical tank portion 201. In addition, the blades 202a provided around the rotating shaft 202b are arranged such that their outer peripheral edge portions are close to the inner peripheral surface of the tank portion 201. The rotating shaft 202b is connected to a motor 203 serving as a drive portion, and the screw conveyor 202 rotates in the clockwise direction when viewed from above by being driven by the motor 203.

[0040] In addition, in the present embodiment, on the surface of the blade 202a of the screw conveyor 202 that conveys the hydrogen carrier, a catalyst substance 205 for promoting the reaction between the hydrogen carrier and the liquid is movably provided. The catalyst substance 205 is configured as a sphere having a Konpeito shape, the sphere is provided with a plurality of spikes, and its surface is coated with a catalyst substance such as Raney nickel. In addition, the surface of the blade 202a can also be coated with the catalyst substance. [Hydrogen Carrier Storage Tank]

[0041] As described above, the hydrogen carrier storage tank 101 stores the hydrogen carrier and accumulates by-products. The hydrogen carrier storage tank 101 can be formed of any material as long as the material can store the powder without leakage, and is formed of, for example, resin. In the present embodiment, the hydrogen carrier storage tank 101 stores sodium borohydride powder as the hydrogen carrier, and accumulates sodium metaborate powder as the by-product after the reaction. The hydrogen carrier storage tank 101 can be separated from the hydrogen generation device 300 and carry sodium borohydride as fuel. In addition, after all the sodium borohydride is used up, the sodium metaborate powder can be stored, so that the sodium metaborate as waste can be carried.

[0042] A separation membrane 102 that divides the internal area is provided in the hydrogen carrier storage tank 101. The separation membrane 102 functions to divide the interior of the hydrogen carrier storage tank 101 into two regions so that the powders stored in the respective regions do not mix together. That is, as described above, the separation membrane 102 divides the interior of the hydrogen carrier storage tank 101 into a hydrogen carrier storage portion 101a and a by-product accumulation portion 101b.

[0043] The separation membrane 102 configured in this way is formed of a soft and elastic material and can change the volume of each of the hydrogen carrier storage portion 101a and the by-product accumulation portion 101b. That is, in the initial state of the hydrogen carrier storage tank 101, that is, the state in which its interior is filled with the hydrogen carrier and no by-products are accumulated therein, the separation membrane 102 extends to the vicinity of the upper part of the hydrogen carrier storage tank 101, as Figure 5 shown. In this state, the volume of the hydrogen carrier storage portion 101a is sufficiently larger than the volume of the by-product accumulation portion 101b, so that a large amount of hydrogen carrier can be stored in the hydrogen carrier storage portion 101a.

[0044] At the same time, in the case where the hydrogen carrier is used and by-products generated by the hydrogen generation reaction in the hydrogen generation device 300 start to accumulate in the by-product accumulation portion 101b, the hydrogen carrier in the hydrogen carrier storage portion 101a starts to decrease, and the by-products in the by-product accumulation portion 101b start to increase. In this case, since the by-products accumulate on the upper surface of the separation membrane 102, the separation membrane 102 is stretched downward due to its weight. In this case, the volume of the hydrogen carrier storage portion 101a gradually decreases, and the volume of the by-product accumulation portion 101b gradually increases, so that more by-products can accumulate in the by-product accumulation portion 101b. In addition, as Figure 6 shown, when the internal hydrogen carrier is used up, the separation membrane 102 is stretched to the vicinity of the lower part of the tank portion 201, the volume of the by-product accumulation portion 101b is sufficiently larger than the volume of the hydrogen carrier storage portion 101a, and a large amount of by-products accumulate in the by-product accumulation portion 101b. In this state, since only the by-products are stored in the hydrogen carrier storage tank 101, the hydrogen carrier storage tank 101 is replaced.

[0045] Note that although it is envisioned that the hydrogen carrier storage tank 101 stores both sodium borohydride and sodium metaborate, it is also possible to store sodium borohydride and sodium metaborate in separate cartridges. [Hydrogen Carrier Supply Section]

[0046] As Figure 2 shown, the hydrogen carrier supply section 110 includes a powder delivery pipe 111, a screw (not shown) provided in the powder delivery pipe 111, and a motor 112 that serves as a drive section for driving the screw. The powder delivery pipe 111 is connected to the lower part of the hydrogen carrier storage tank 101, and the hydrogen carrier is supplied by gravity from the hydrogen carrier storage section 101a that stores the hydrogen carrier into the powder delivery pipe 111. The downstream end of the powder delivery pipe 111 in the powder transfer direction is connected to the first supply port 204a of the tank section 201.

[0047] By rotating the screw by the motor 112, the hydrogen carrier supply section 110 configured in this way conveys the hydrogen carrier powder supplied from the hydrogen carrier storage section 101a to the powder delivery pipe 111 to the first supply port 204a. Thereby, the hydrogen carrier is transferred from the hydrogen carrier storage tank 101 into the tank section 201. [By-Product Collection Section]

[0048] As Figure 2 shown, the by-product collection section 210 includes a powder delivery pipe 211, a screw (not shown) provided in the powder delivery pipe 211, and a motor 212 that serves as a drive section for driving the screw. The upstream end of the powder delivery pipe 211 in the powder transfer direction is connected to the second collection port 201b of the tank section 201. The by-products generated in the tank section 201 are conveyed upward by the screw conveyor 202 and sent to the upstream end of the powder delivery pipe 211 through the second collection port 201b. The downstream end of the powder delivery pipe 211 in the powder transfer direction is connected to the upper part of the hydrogen carrier storage tank 101. The by-products conveyed in the powder delivery pipe 211 are supplied to the by-product accumulation section 101b that accumulates the by-products.

[0049] By rotating the screw by the motor 212, the by-product collection section 210 conveys the hydrogen carrier powder supplied from the tank section 201 through the second collection port 201b to the powder delivery pipe 211 to the by-product accumulation section 101b of the hydrogen carrier storage tank 101. Thereby, the by-products are transported from the tank section 201 to the hydrogen carrier storage tank 101. [Temperature Regulation Section]

[0050] By using Figure 7 it will be described with reference to Figure 1The detailed structure of the temperature adjustment unit 305. Here, the reaction of Chemical Formula (1) is an exothermic reaction. Therefore, the temperature in the box part 201 rises as the reaction proceeds. The temperature adjustment unit 305 is provided to suppress this and adjust the temperature in the box part within a predetermined temperature range (for example, a temperature range set to be higher than 0 °C and equal to or lower than 80 °C).

[0051] The temperature adjustment unit 305 includes a first pipe 801, a second pipe 802, a radiator 803 serving as a heat exchanger, a pump 804, a fan 805, and a temperature sensor 806. The first pipe 801 is a pipe for connecting the radiator 803 and the rotating shaft 202b of the screw conveyor 202 and supplying a heat medium such as water from the radiator 803 to the rotating shaft 202b. The second pipe 802 is a pipe for connecting the rotating shaft 202b to the radiator 803 and collecting the heat medium that has passed through the rotating shaft 202b. The first pipe 801 and the second pipe 802 are integrated with each other or connected to each other, and are provided so as to pass through the rotating shaft 202b and the motor 203.

[0052] The radiator 803 performs heat exchange between the heat medium sent from the second pipe 802 and the surrounding air, and sends the heat medium that has undergone heat exchange to the first pipe 801. The pump 804 sucks and discharges the heat medium so that the heat medium flows in the first pipe 801, the second pipe 802, and the radiator 803. In the present embodiment, the pump is provided in the second pipe 802. The pump can be provided at any position in the flow path of the heat medium and can be provided in the first pipe 801.

[0053] The fan 805 is provided to send air to the radiator 803. The temperature sensor 806 is provided in the box part 201 and detects the temperature inside or outside the box part 201. When the temperature sensor 806 reaches a preset lower limit temperature, a controller (not shown) drives the pump 804, so that the heat medium flows in one direction in the path constituted by the first pipe 801, the second pipe 802, and the radiator 803. At this time, the fan 805 is also driven. The heat medium obtains heat in the box part 201, the obtained heat is cooled by the radiator 803, and the radiator 803 is cooled by the fan 805. Then, when the temperature sensor 806 reaches a preset predetermined temperature, the controller stops driving the pump 804 and the fan 805. Thereby, the temperature in the box part 201 is adjusted within a predetermined temperature range. [Operation of Hydrogen Generation Device]

[0054] The operation of the hydrogen generation device 300 configured as described above will be described. A controller (not shown) drives the motor 112 of the hydrogen carrier supply unit 110, and thereby supplies the hydrogen carrier from the hydrogen carrier storage tank 101 to the first supply port 204a provided at the lower part of the reaction tank 200 through the powder transfer pipe 111. The hydrogen carrier supplied to the first supply port 204a is gradually conveyed upward from the lower part by the screw conveyor 202 driven by the motor 203. At the same time, the aqueous liquid is supplied from the liquid supply unit 301 to the second supply port 204 of the reaction tank 200. Then, in the tank part 201, the hydrogen carrier conveyed by the screw conveyor 202 reacts with the liquid supplied from the first supply port 204a, and hydrogen gas and by-product powder are generated.

[0055] In the case where the hydrogen carrier is sodium borohydride, the sodium borohydride moving upward on the screw conveyor 202 moves upward while being converted into sodium metaborate by reacting with the liquid supplied from the second supply port 204. The concentration of sodium metaborate increases as the sodium borohydride supplied from the lowermost part of the tank part 201 moves upward in the tank part 201, and at the uppermost part, it is all sodium metaborate.

[0056] In addition, the hydrogen carrier is conveyed through the upper surface of the blade 202a of the screw conveyor 202, and since the catalyst substance 205 exists on the upper surface of the blade 202a, the reaction is promoted. The plurality of catalyst substances 205 having a spherical shape exhibit a catalytic function of promoting the reaction of Chemical Formula (1) while freely moving on the upper surface of the blade 202a.

[0057] The hydrogen generated in the tank part 201 is collected by the hydrogen collection unit 304 through the first collection port 206 provided in the upper part of the tank part 201. At the same time, the by-products generated together with the hydrogen are conveyed upward by the screw conveyor 202, and are sent to the powder transfer pipe 211 of the by-product collection unit 210 through the second collection port 201b provided in the upper part of the tank part 201. The by-products supplied to the powder transfer pipe 211 are sent to the hydrogen carrier storage tank 101 by the screw rotated by the motor 203, and are accumulated in the by-product accumulation part 101b.

[0058] It should be noted that the liquid supplied from the second supply port 204 flows from the upper side to the lower side on the screw conveyor 202, and the reaction of Chemical Formula (1) is caused during this process. The liquid remaining without being used for this reaction accumulates in the lower part of the tank part 201, and then is discharged from the discharge port 207 provided in the lower part of the tank part 201, and is collected by the liquid collection unit 303.

[0059] Repeat this operation, and when the hydrogen carrier stored in the hydrogen carrier storage section 101a of the hydrogen carrier storage tank 101 is used up and the by-products accumulate in the by-product accumulation section 101b, replace the hydrogen carrier storage tank 101. Connect a new hydrogen carrier storage tank 101 that stores only the hydrogen carrier to the hydrogen generation device 300, and generate hydrogen as described above.

[0060] In the case of this embodiment configured in this way, hydrogen gas is generated in the tank section 201 by supplying a liquid while gradually conveying the hydrogen carrier by the screw conveyor 202. Therefore, a hydrogen generation device that can easily promote the reaction between the hydrogen carrier and the aqueous liquid can be provided.

[0061] For example, in the case of adopting a configuration in which a non-rotating spiral plate is provided instead of the screw conveyor 202 and the hydrogen carrier moves along the spiral plate by gravity, there is a possibility that the hydrogen carrier powder stays on the spiral plate and hydrogen cannot be continuously generated. In contrast, in this embodiment, since hydrogen is generated while the hydrogen carrier is conveyed by the screw conveyor 202, even if the hydrogen carrier is powder, hydrogen can be continuously generated, and thus the reaction between the hydrogen carrier and the aqueous liquid can be easily promoted.

[0062] In addition, in this embodiment, the hydrogen carrier is configured to be conveyed by the screw conveyor 202, so the flexibility of the shape and layout of the device is higher than that of the configuration in which the hydrogen carrier moves on the spiral plate by gravity. For example, as Figure 8 shown in another example, the hydrogen generation section 302 can be inclined with respect to the direction of gravity. That is, in the above description, the hydrogen carrier storage tank 101 is configured such that by-products are stored in its upper part and the hydrogen carrier is stored in its lower part, and the hydrogen carrier moves from the lower side to the upper side in the tank section 201. Therefore, the hydrogen carrier storage tank 101, the tank section 201, and the screw conveyor 202 are arranged along the direction of gravity.

[0063] However, the hydrogen generation device 300 of this embodiment is not limited to this form. For example, as Figure 8 shown in other examples, the hydrogen carrier storage tank 101, the tank section 201, and the screw conveyor 202 are arranged inclined with respect to the direction of gravity. In addition, they can also be arranged in the horizontal direction.

[0064] In addition, the powder conveying pipes 111 and 211 connecting the hydrogen carrier storage tank 101 and the tank section 201 are not limited to a straight shape and can be configured to include a bent portion. Therefore, the positional relationship between the hydrogen carrier storage tank 101 and the tank section 201 in the vertical direction is not limited to the above relationship and can be vertically flipped.

[0065] In addition, in the present embodiment, the advantage of conveying the hydrogen carrier by the screw conveyor 202 is that the hydrogen carrier powder moves spirally in the tank portion 201, so that a long path can be ensured as the reaction path between the hydrogen carrier and the liquid. In addition, the screw conveyor 202 has the property of stirring the conveyed material, and the reaction between the hydrogen carrier and the liquid is promoted by this property.

[0066] In addition, in the present embodiment, the advantage of storing the by-product and the hydrogen carrier in the upper and lower parts of the hydrogen carrier storage tank 101 respectively is that the by-product can be filled and the hydrogen carrier can be discharged by using gravity. As a result, the powder is less likely to block the path, and the energy consumption can be reduced.

[0067] In addition, in the present embodiment, as described above, since the hydrogen carrier storage tank 101 can be detached from the apparatus main body, when the hydrogen carrier is used up, hydrogen can be re-extracted by replacing it with another hydrogen carrier storage tank 101. The detached hydrogen carrier storage tank 101 can be used as a container for carrying the by-product, and for example, sodium metaborate can be restored to sodium borohydride and re-filled into the hydrogen carrier storage tank 101.

[0068] Furthermore, in the present embodiment, the production rate of hydrogen can be controlled by changing each motor and the liquid supply amount. The motors 112, 203, and 212 can be controlled independently of each other. For example, control can be performed such that the motors 203 and 212 are driven until no powder remains in the tank portion 201 when the driving of the motor 112 stops, and then the motors 203 and 212 stop. Industrial Applicability

[0069] The hydrogen production apparatus according to the present invention is preferably used for a hydrogen production apparatus that produces hydrogen by using a hydrogen carrier as a raw material, and the hydrogen carrier has the property of generating hydrogen when an aqueous liquid is poured thereon. In addition, the reaction tank according to the present invention is preferably used for a reaction tank that reacts a liquid with a hydrogen carrier. List of Reference Numerals

[0070] 101: Hydrogen carrier storage tank (cartridge) 101a: Hydrogen carrier storage portion 101b: By-product accumulation portion 110: Hydrogen carrier supply portion 200: Reaction tank 201: Tank portion 201a: First supply port 202: Screw conveyor 202a: Blade 202b: Rotating shaft 204: Second supply port (supply port) 205: Catalyst substance 206: First collection port (first connection port) 206a: Breathable lid 207: Discharge port (second connection port) 207a: Liquid-permeable lid 210: By-product collection section 300: Hydrogen generation device 301: Liquid supply section 302: Hydrogen generation section 303: Liquid collection section 304: Hydrogen collection section 305: Temperature control section

Claims

1. A hydrogen generation device, comprising: A tank portion; A hydrogen carrier supply unit configured to supply a solid hydrogen carrier to the tank portion; A screw conveyor disposed in the tank portion and including screw blades for conveying the hydrogen carrier supplied by the hydrogen carrier supply unit; A liquid supply unit configured to supply a liquid containing water to the hydrogen carrier conveyed by the screw conveyor; and A hydrogen collection unit configured to collect hydrogen generated by the reaction between the hydrogen carrier and the liquid on the screw conveyor.

2. The hydrogen generation device according to claim 1, wherein, The screw conveyor is configured to convey the hydrogen carrier from the lower side to the upper side.

3. The hydrogen generation device according to claim 1, wherein, A catalyst substance for promoting the reaction between the hydrogen carrier and the liquid is movably provided on the surface of the blade for conveying the hydrogen carrier.

4. The hydrogen generation device according to claim 1, wherein The surface of the blade for conveying the hydrogen carrier is coated with a catalyst substance for promoting the reaction between the hydrogen carrier and the liquid.

5. The hydrogen generation device according to claim 1, wherein the tank portion has a plurality of supply ports for supplying the liquid supplied from the liquid supply unit into the tank portion.

6. The hydrogen generation device according to claim 1, Among them, The screw conveyor includes a rotating shaft equipped with the blades thereon, and wherein the rotating shaft has a supply port for supplying the liquid supplied from the liquid supply unit into the tank portion.

7. The hydrogen generation device according to claim 1, Among them, The tank portion has a first connection port connected to the hydrogen collection unit, and wherein the first connection port is equipped with a breathable cover having breathability to allow gas to pass through it but not allow solids to pass through it.

8. The hydrogen generation device according to claim 1, further comprising: A liquid collection unit configured to collect the liquid from the tank portion, Among them, The tank portion has a second connection port connected to the liquid collection unit, and wherein the second connection port is equipped with a liquid-permeable cover having liquid permeability to allow liquid to pass through it but not allow solids to pass through it.

9. The hydrogen generation device according to claim 8, wherein the liquid collection unit is configured to supply the liquid that has been collected from the tank portion and from which foreign substances have been removed to the liquid supply unit.

10. The hydrogen generation device according to claim 1, further comprising: A hydrogen carrier storage tank configured to store the hydrogen carrier to be supplied by the hydrogen carrier supply unit to the tank portion, Among them, The hydrogen carrier storage tank body can be attached to and detached from the tank portion.

11. The hydrogen generation device according to claim 1, further comprising a by-product collection unit configured to collect by-products generated by the reaction between the hydrogen carrier and the liquid on the screw conveyor and conveyed by the screw conveyor.

12. The hydrogen generation device according to claim 11, further comprising: A cartridge that can be attached to and detached from the tank portion and the cartridge includes: A hydrogen carrier storage unit configured to store the hydrogen carrier to be supplied by the hydrogen carrier supply unit to the tank unit; A by-product accumulation unit configured to accumulate the by-products collected by the by-product collection unit; and A partition member configured to partition the hydrogen carrier storage unit and the by-product accumulation unit from each other, wherein the partition member is elastic and can change the volume of each of the hydrogen carrier storage unit and the by-product accumulation unit.

13. The hydrogen generation device according to claim 1, further comprising a temperature adjustment unit configured to adjust the temperature in the tank unit to a predetermined temperature.

14. The hydrogen generation device according to claim 13, Among them, The screw conveyor includes a rotating shaft equipped with blades, and wherein the temperature adjustment unit includes A first pipe for supplying a heat medium to the rotating shaft, A second pipe for collecting the heat medium that has passed through the rotating shaft, and A heat exchanger configured to perform heat exchange between the heat medium sent to the heat exchanger through the second pipe and the air around it, and send the heat medium after the heat exchange to the first pipe.

15. A reaction tank configured to react a solid hydrogen carrier with a water-containing liquid to generate hydrogen, the reaction tank comprising: A tank unit equipped with a first supply port for supplying the hydrogen carrier, a second supply port for supplying the liquid, and a collection port for collecting hydrogen generated by the reaction between the hydrogen carrier and the liquid; and A screw conveyor provided in the tank unit and including screw blades for conveying the hydrogen carrier supplied from the first supply port and reacting the conveyed hydrogen carrier with the liquid supplied from the second supply port.

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