Hydrogen generator

Abstract

To provide a hydrogen generator 1 which easily promotes a reaction between a hydrogen carrier and a liquid containing water.SOLUTION: There is provided a hydrogen generator 1 which has a liquid discharge device 22 for imparting a liquid containing at least water to a solid hydrogen carrier and a control part for controlling an amount of the liquid imparted by the liquid discharge device 22 to the hydrogen carrier.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a hydrogen generating device that generates hydrogen using a hydrogen carrier as a raw material, which has the property of generating hydrogen when a liquid containing water is poured on it. [Background technology]

[0002] As a hydrogen generating device, a device has been proposed in which water and a solvent are supplied to sodium borohydride to hydrolyze the sodium borohydride and generate hydrogen (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-114708 A Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned Patent Document 1 does not describe a specific configuration for supplying water and a solvent to sodium borohydride. A hydrogen generating device is required to stably proceed with the hydrolysis reaction of a hydrogen carrier such as sodium borohydride.

[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 a liquid containing water. [Means for solving the problem]

[0006] The hydrogen generation device of the present invention is characterized by having a first liquid application device that applies a liquid containing at least water to a solid hydrogen carrier, and a control unit that controls the amount of the liquid applied by the first liquid application device to the hydrogen carrier.

[0007] In addition, the hydrogen generation device of the present invention comprises a liquid application device that applies a liquid containing water to a solid hydrogen carrier, and a hydrogen recovery device that recovers hydrogen generated by the reaction between the hydrogen carrier and the liquid, and is characterized in that the liquid application device applies the liquid in the form of droplets toward the hydrogen carrier. Effect of the Invention

[0008] According to the present invention, it is possible to provide a hydrogen generation device that can easily promote the reaction between a hydrogen carrier and a liquid containing water. [Brief description of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view showing a schematic configuration of a hydrogen generation device according to a first embodiment. [Diagram 2] FIG. 2 is a control block diagram of the hydrogen generation apparatus according to the first embodiment. [Diagram 3] FIG. 2A is a schematic cross-sectional view of a thermal inkjet head, and FIG. 2B is a schematic cross-sectional view of a piezoelectric inkjet head. [Figure 4] FIG. 1 is a perspective view showing a schematic configuration of a line-type inkjet head. [Diagram 5] FIG. 1 is a perspective view showing a schematic configuration of a serial type inkjet head. [Figure 6] FIG. 5 is a cross-sectional view showing a schematic configuration of a hydrogen generation device according to a second embodiment. [Figure 7] FIG. 11 is a cross-sectional view showing a schematic configuration of a hydrogen generation device according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] <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).

[0011] One problem 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 70 MPa 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.

[0012] 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, ammonia and methylcyclohexane 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.

[0013] Among these hydrogen carrier materials, metal hydrides such as sodium borohydride are widely known, from which hydrogen can be easily extracted by pouring water on them. 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, this method requires a larger amount of water than is theoretically required according to the reaction formula, which results in a decrease in the actual volumetric energy density.

[0014] In this embodiment, the hydrogen generating device described below generates hydrogen by pouring a liquid containing water onto a solid hydrogen carrier. In addition, the by-products generated by the reaction between the hydrogen carrier and the liquid are collected. The by-products can be recycled into hydrogen carriers.

[0015] [Hydrogen generator] The schematic configuration of the hydrogen generation device 1 will be described with reference to Fig. 1. The hydrogen generation device 1 of this embodiment is a device that places a solid (powder in this embodiment) hydrogen carrier on a conveyor belt 41 (on a conveying member), discharges a liquid containing water onto it, and reacts the hydrogen carrier with the liquid containing water on the conveyor belt 41 to generate hydrogen. The hydrogen generation device 1 mainly includes the conveyor belt 41, a powder application device 12 as an application device, a liquid discharge device 22 as a discharge device, a hydrogen recovery device 31, and a by-product recovery device 61.

[0016] The conveyor belt 41 rotates in the direction of the arrow in Fig. 1. The powder coating device 12 receives a supply of hydrogen carriers from a hydrogen carrier storage case 11 that stores powdered hydrogen carriers, and applies the hydrogen carriers to a surface 41a of the conveyor belt 41. The liquid ejection device 22 is disposed downstream of the powder coating device 12 in the rotation direction of the conveyor belt 41, receives a supply of liquid from a liquid storage case 21 that stores a liquid including water, and ejects the liquid onto the hydrogen carriers applied to the surface 41a of the conveyor belt 41.

[0017] The hydrogen recovery device 31 is disposed downstream of the liquid discharge device 22 in the rotation direction of the conveyor belt 41, and recovers hydrogen generated by the reaction between the hydrogen carrier and the liquid on the surface 41a of the conveyor belt 41. The by-product recovery device 61 recovers by-products generated by the reaction between the hydrogen carrier and the liquid on the surface 41a of the conveyor belt 41. The by-products referred to here refer to products other than hydrogen generated by the reaction between the hydrogen carrier and the liquid. The hydrogen generation device 1 of this embodiment further includes a heating device 51 for heating the conveyor belt 41. The heating device 51 may be omitted.

[0018] This hydrogen generation device 1 can carry out a series of processes, such as generating hydrogen through a reaction between a hydrogen carrier and a liquid containing water on the conveyor belt 41 and collecting by-products after the reaction. Therefore, it has an advantage that hydrogen can be generated continuously and stably for a long period of time with a compact device configuration.

[0019] The operation of the hydrogen generation device 1 is as follows. First, the conveyor belt 41 starts operating, and at the same time, the heating device 51 starts heating. When the conveying speed of the conveyor belt 41 stabilizes at a predetermined speed and the surface temperature of the conveyor belt 41 reaches a set temperature, the powder coating device 12 starts operating and applies the hydrogen carrier onto the conveyor belt 41. The liquid is discharged from the liquid discharge device 22 in time with the hydrogen carrier coming under the liquid discharge device 22, a reaction between the hydrogen carrier and the liquid is initiated, and the generated hydrogen is collected by the hydrogen recovery device 31. If the hydrogen generation device 1 does not include the heating device 51, the hydrogen carrier may be applied onto the conveyor belt 41 regardless of the temperature of the conveyor belt 41.

[0020] Thereafter, the by-products generated after the reaction between the hydrogen carrier and the water-containing liquid are transported to a by-product recovery device 61, where the by-products are recovered and sent to a by-product recovery case 62. Next, each component will be described in detail.

[0021] [Hydrogen Carrier] The "hydrogen carrier" in this embodiment is not particularly limited as long as it is a solid hydrogen carrier that generates hydrogen when a liquid containing water is poured on it. 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. In addition, additives such as a reaction promoter and a desiccant can be included.

[0022] It is preferable to use sodium borohydride as the hydrogen carrier. This is because the ratio of hydrogen in the sodium borohydride molecule is high relative to the molecular weight of sodium borohydride, and the energy density is high. In addition, the hydrogen generation reaction proceeds at low temperatures close to room temperature, so hydrogen can be obtained efficiently, and it is less likely to ignite even when it comes into contact with water, so there are fewer safety concerns.

[0023] In addition, as the hydrogen carrier of this embodiment, a solid such as a powder or granule is preferable, 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, and more preferably a particle size of about 10 μm to 100 μm. In addition, when using it in a sheet or pellet form, it is preferable to perform surface roughening, porous treatment, etc., in order to increase the surface area and the contact area with the water-containing liquid, from the viewpoint of increasing the reactivity with the water-containing liquid.

[0024] In this embodiment, sodium borohydride powder with an average particle size of 50 μm is used as the solid hydrogen carrier. The average particle size of the solid hydrogen carrier is not limited to this. The powdered sodium borohydride reacts with water to generate hydrogen. The reacted sodium borohydride changes into a by-product, powdered sodium metaborate. This reaction is expressed by the following chemical formula. NaBH 4 (Sodium borohydride)+2H 2 O(Wed) →NaBO 2 (Sodium metaborate) + 4H 2 (Hydrogen) (1)

[0025] This reaction (chemical formula (1)) is known to be promoted by Raney catalysts made from metals such as nickel, cobalt, and copper, and by acidic solutions such as citric acid and acetic acid.

[0026] [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 poured 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] [catalyst] Examples of catalyst materials that can be used in combination with the hydrogen carrier include platinum group metals such as platinum (Pt), ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), and iridium (Ir), Raney catalysts made from metals such as cobalt (Co), nickel (Ni), and copper (Cu), and fluorinated hydrogen storage alloys. It is desirable for the catalyst to be formed so that its surface area is large. For example, the catalyst may be structured so that the catalyst material is supported on porous materials such as gamma alumina and alpha alumina, or on carbon powder. The speed of hydrogen generation can be adjusted by increasing the contact area between the hydrogen carrier and the catalyst material.

[0034] [Desiccant] Hydrogen carriers react with liquids, including water, to generate hydrogen. As a result, they may also react with water in the external environment, such as moisture in the air, generating trace amounts of hydrogen. This results in a decrease in energy density. In addition, unexpected hydrogen generation may cause safety concerns, such as deformation or damage to the device due to an increase in internal pressure in the hydrogen carrier case 11, or ignition due to hydrogen leaking to the outside.

[0035] To prevent this, a desiccant can be used. The desiccant may be mixed with the hydrogen carrier. A bag that is permeable to air and water vapor and contains a desiccant may be enclosed inside the hydrogen carrier storage case 11. Also, a bag containing a desiccant may be attached to the hydrogen carrier storage case 11 so that the desiccant is not mixed with the hydrogen carrier. Examples of desiccant include calcium oxide (quicklime), calcium chloride, silica gel, molecular sieve, polyacrylic acid, silica alumina gel, etc., but are not limited to the above-mentioned substances as long as they contribute to drying.

[0036] [Temperature of liquids containing water> The temperature of the water-containing liquid is preferably higher than 0° C. and lower than 80° C. If the temperature is lower than 0° C., part of the water-containing liquid will freeze, changing the concentration of the components of the water-containing liquid, and there is a possibility that the intended amount of hydrogen generation will not be obtained. On the other hand, if the temperature exceeds 80° C., the water-containing liquid will evaporate more, changing the concentration of the components of the water-containing liquid, and there is a possibility that the intended amount of hydrogen generation will not be obtained.

[0037] The rate of hydrogen generation can be adjusted by controlling the temperature of the water-containing liquid. In this case, the temperature of the water-containing liquid can be measured by a contact or non-contact thermometer (not shown) installed inside or outside the liquid container 21 or the liquid discharge device 22. The temperature of the water-containing liquid can be adjusted by using a temperature adjustment device (a heating device, a cooling device (not shown)) inside or outside the liquid container 21 or the liquid discharge device 22. The temperature may also be adjusted by natural heat dissipation or the like.

[0038] [Amount of water-containing liquid relative to hydrogen carrier] As will be described in detail later, the hydrogen generation device 1 of this embodiment is adapted to control the amount of water-containing liquid to be applied to the hydrogen carrier. The amount to be applied is controlled by a central control device (described later). The central control device receives signals obtained from hydrogen applications such as fuel cells supplied by the hydrogen generation device 1 and from each device of the hydrogen generation device 1, and controls the amount to be applied based on a program stored in advance.

[0039] For example, when sodium borohydride is used as a hydrogen carrier, it generates hydrogen by reacting with a liquid containing water. The sodium borohydride reacts and changes to sodium metaborate. The chemical formula for this reaction is shown in chemical formula (1) above.

[0040] According to chemical formula (1), it is best to control the amount of liquid containing 2 moles of water to 1 mole of sodium borohydride. This is because it maximizes the energy density. However, when increasing the reaction rate of sodium borohydride, such as at the start of the hydrogen generation reaction, the more water there is, the more the reaction will proceed, so in some cases a liquid containing more than 2 moles of water may be added.

[0041] Since sodium metaborate is known to exist as a hydrate, when a liquid containing 2 mol or more of water is added, sodium metaborate remains as a hydrate after the reaction. Since sodium metaborate exists as a maximum of 4 hydrate, when a liquid containing 6 mol or less of water is added, sodium metaborate hydrate remains after the reaction. When a liquid containing 6 mol of water is added, there is an excess of water, and sodium metaborate 4 hydrate and water remain after the reaction. In order to avoid an excessive decrease in energy density and to reduce the amount of product recovered after the reaction, it is preferable to add a liquid containing 2 mol or more and 6 mol or less of water.

[0042] [Conveyor belt] The conveyor belt 41 as a conveying member is an endless belt and can convey a solid hydrogen carrier. The conveyor belt 41 is stretched by a driving roller 42 and a driven roller 43. The driving roller 42 is fixed, and a force is applied to the driven roller 43 by a biasing force of a biasing spring (not shown) so as to push the conveyor belt toward the surface side, and a certain tension is applied to the conveyor belt 41 by this force. The driving roller 42 is connected to a driving unit 41b (see FIG. 2) such as a motor, and the driving unit 41b drives the driving roller 42 to rotate, so that the conveyor belt 41 moves around (i.e., rotates) in the clockwise direction (direction of the arrow) in FIG. 1. In this embodiment, the conveyor belt 41 is supported by two rollers, but a configuration in which the conveyor belt 41 is supported by a plurality of rollers, for example, three rollers, may be used.

[0043] In either case, the conveyor belt 41 has a tension surface stretched by two rollers (a driving roller 42 and a driven roller 43 in this embodiment), i.e., the above-mentioned surface 41a, disposed in a substantially horizontal direction. Also, this surface 41a faces upward, and the powder coating device 12, the liquid discharge device 22, and the hydrogen recovery device 31 disposed above the conveyor belt 41 face the surface 41a.

[0044] Such a conveyor belt 41 has a mechanism that conveys the hydrogen carrier coated on the conveyor belt 41 from the powder coating device 12 downstream in the rotation direction, through the liquid discharge device 22 and the hydrogen recovery device 31 in that order. Thereafter, the by-products after the reaction are conveyed further downstream, and are conveyed to the by-product recovery device 61. In addition, a heating device 51 that heats the conveyor belt 41 from its inner circumferential surface is provided on the inside of the conveyor belt 41.

[0045] The conveyor belt 41 is preferably conductive from the viewpoint of not generating static electricity, and may be made of metal or resin. If it is made of metal, aluminum, iron, copper, Ni, stainless steel (SUS), etc. can be used. If it is made of resin, it is preferably a resin with a high glass transition point from the viewpoint of heat resistance, and engineering plastics having high heat resistance and high durability such as polyimide, polyamideimide, and polyetheretherketone are preferable. In the case of a resin that does not have conductivity, it is preferable to make it contain an antistatic agent such as carbon black to make it conductive. In addition, the thickness of the conveyor belt 41 is preferably about 30 μm or more and 200 μm or less from the viewpoint of thermal conductivity. In this embodiment, an endless belt made of resin that is made conductive by containing carbon in polyimide is used as the conveyor belt 41.

[0046] The conveying speed (rotation speed) of the conveyor belt 41 is a predetermined speed set for each type of hydrogen carrier and liquid including water used. It is preferable that the conveying speed can be adjusted appropriately depending on the amount of hydrogen required. In this way, when the amount of hydrogen recovered by the hydrogen recovery device 31 does not reach the planned amount, the amount of generated hydrogen can be adjusted by adjusting the conveying speed appropriately according to the amount of hydrogen measured by a flow rate sensor 32 (see FIG. 2) that measures the flow rate of hydrogen recovered by the hydrogen recovery device 31.

[0047] [Powder coating device] The powder coating device 12 is a device that receives a supply of the hydrogen carrier from the hydrogen carrier storage case 11 and coats the hydrogen carrier onto the conveyor belt 41. There is no problem with the thickness of the hydrogen carrier coated onto the conveyor belt 41 being about 50 μm or more and 3 mm or less, but in order to improve reactivity with the reaction liquid containing water, it is preferable that the thickness be 50 μm or more and 500 μm or less.

[0048] Moreover, the hydrogen carrier housing case 11 serving as a hydrogen carrier supply container houses a hydrogen carrier (hydrogen carrier for supply) for supplying to the housing section of the powder coating device 12. This hydrogen carrier housing case 11 is detachable from the powder coating device 12. That is, the hydrogen carrier housing case 11 is replaceable.

[0049] [Liquid discharge device] The liquid ejection device (first liquid application device) 22 is a liquid application device that receives a supply of a water-containing liquid from a liquid storage case 21 that stores a water-containing liquid, and applies the water-containing liquid to the hydrogen carrier on the conveyor belt 41. The liquid ejection device 22 is capable of adjusting the amount of the water-containing liquid relative to the amount of the hydrogen carrier. It is preferable that the liquid ejection device 22 ejects the liquid onto the conveyor belt 41 without contacting the conveyor belt 41.

[0050] The non-contact type liquid discharge device 22 may be a spray type, a dispenser type, an inkjet type, or any other type that can dispense a water-containing liquid in droplets to the hydrogen carrier, as described below. By discharging the liquid to the hydrogen carrier in droplet form, the contact area between the hydrogen carrier and the liquid increases, thereby increasing the reaction rate. In addition, since the water-containing liquid can be dispensed very thinly over a wide area, the generation of bubbles during hydrogen generation can be suppressed.

[0051] In the non-contact liquid discharge device 22, it is possible to adjust the amount of water-containing liquid relative to the hydrogen carrier. For example, the amount of water-containing liquid dispensed can be adjusted by adjusting the diameter and number of nozzles used when dispensing the water-containing liquid and the pressure applied to the liquid. If the device has an electrical control unit, the amount of water-containing liquid dispensed can be adjusted by opening and closing the flow path of the water-containing liquid. The amount of water dispensed can be controlled by information based on the amount of hydrogen generated or by external input.

[0052] A contact type liquid application device may be used in combination with a non-contact type liquid ejection device. Examples of contact type liquid application devices include gravure offset rollers, bar coaters, die coaters, blade coaters, and knife coaters. In the case of a contact type liquid application device, the amount of liquid applied can be adjusted by adjusting the type of roller, the contact pressure with the belt carrying the hydrogen carrier, the contact pressure between the blade and the roller, and the like.

[0053] Moreover, the liquid containing case 21 serving as a liquid supply container contains liquid including water to be supplied to the liquid ejection device 22. The liquid containing case 21 is detachable from the liquid ejection device 22. That is, the liquid containing case 21 is replaceable.

[0054] [Hydrogen recovery equipment] The hydrogen recovery device 31 is for collecting hydrogen generated by the reaction between the hydrogen carrier and a liquid containing water. As shown in FIG. 1, it may have a canopy structure, which is called an exhaust device, or the upper outer wall of the hydrogen generation device 1 may be sloped and have an exhaust outlet at the highest position. There is no problem as long as the structure is such that hydrogen generated inside the hydrogen generation device 1 can be collected. The hydrogen recovery device 31 of this embodiment is disposed above the conveyor belt 41 and has a collection section 31a that collects hydrogen generated on the conveyor belt 41 and a suction fan 31b that sucks in the hydrogen collected by the collection section 31a. The hydrogen sucked in by the suction fan 31b is supplied to a supply destination such as a fuel cell through a pipe 31c.

[0055] Fuel cells, which are one of the hydrogen supply destinations, require dry hydrogen. However, the collected gas may contain not only hydrogen but also water vapor and evaporated alkaline substances produced by the reaction. For this reason, it is preferable to provide a mechanism for removing substances other than hydrogen from the gas, such as a filter containing water or silica gel, or a steam trap with a cooling device, in the hydrogen flow path such as the pipe 31c.

[0056] [By-product recovery equipment] The by-product recovery device 61 as a solid product recovery device removes the by-products on the conveyor belt 41 from the conveyor belt 41 and sends the by-products (solid products) to a by-product recovery case 62. For example, when the hydrogen carrier is sodium borohydride, the by-product becomes sodium metaborate. The by-product recovery device 61 includes a recovery blade 61a that contacts the conveyor belt 41 and a blade holding member (not shown) that holds the recovery blade 61a.

[0057] The recovery blade 61a preferably comes into contact with the outer peripheral surface of the conveyor belt 41, which is stretched by a roller that stretches the conveyor belt 41, which is a drive roller 42 in this embodiment. The recovery blade 61a preferably comes into contact with a surface of the conveyor belt 41 other than the surface 41a, such as the vertical lower surface or horizontal side surface. The by-product recovery case 62 is preferably disposed vertically below the recovery blade 61a. This allows the by-products recovered by the recovery blade 61a to fall by gravity and be recovered by the by-product recovery case 62.

[0058] The recovery blade 61a is not particularly limited in terms of material, but examples thereof include a rubber blade used for cleaning intermediate transfer belts in copiers, etc. This is a rubber blade made of rubber such as silicone rubber or urethane rubber, molded into a plate shape with corners, and is attached so that the corners come into contact in the opposite direction to the moving direction of the conveyor belt 41, thereby removing by-products on the conveyor belt 41. Also, the recovery blade 61a may be a spatula-shaped blade called a scraper, which is made of metal or glass.

[0059] The blade holding member supports the recovery blade 61a and utilizes the flexure of the blade holding member to apply a constant pressure to the recovery blade 61a. There are no particular restrictions on the material, but since pressure is applied, it is preferable that the blade holding member be made of metal.

[0060] Further, by-product recovery case 62 as a recovery container is a case for recovering by-products recovered by recovery blade 61a from conveyor belt 41. This by-product recovery case 62 is detachable from by-product recovery device 61. That is, by-product recovery case 62 is replaceable.

[0061] [Heating device] The heating device 51 heats the inner circumferential surface of the conveyor belt 41 to promote the reaction between the hydrogen carrier and the water-containing liquid and generate hydrogen stably. This makes it possible to stably extract hydrogen without using a reaction promoter such as a catalyst during the hydrolysis reaction of the hydrogen carrier.

[0062] In addition, the method of heating the conveyor belt 41 using the heating device 51 is a method that is more energy efficient in terms of heating than methods such as heating the hydrogen carrier or heating a liquid containing water, because the heating range and timing can be limited to the reaction between the hydrogen carrier and the liquid containing water.

[0063] The heating device 51 may be one that heats the conveyor belt 41 via a film or belt, one that directly transfers heat from a heater to the conveyor belt 41, or one that uses an induction heating heater if the conveyor belt 41 is made of metal. There are no particular limitations as long as it can transfer heat quickly to the conveyor belt 41 and heat the conveyor belt 41. Also, there is no problem with a configuration in which a heater is provided on the outer circumferential surface side of the conveyor belt 41 and directly heats the liquid containing the hydrogen carrier and water. However, when heating from the outer circumferential surface side, contact of hydrogen with the heater should be avoided from the viewpoint of safety, so a configuration in which heating is performed via a heating film or the like is preferable.

[0064] [Central control device] 2 is a block diagram showing the system of the hydrogen generation apparatus 1 of this embodiment. The central control unit 101 comprises a control unit 112, a RAM (Random Access Memory) 111, a storage 113 for storing programs, a communication interface, a signal transmission unit 114, and a signal reception unit 115. The control unit 112 comprises a CPU (Central Processing Unit) or a CPU plus a ROM (Read Only Memory), and issues control commands to the entire hydrogen generation apparatus 1 by executing a program stored in the storage 113.

[0065] The RAM 111 is a main working memory for the control unit 112. The storage 113 is a storage area for storing control programs and the like. The control unit 112 reads out the control programs, temporarily stored time-series data, log information, and the like from the RAM 111 and the storage 113 to perform processing.

[0066] The control unit 112 receives information from an external application 102, such as a hydrogen application, such as a fuel cell supplied by the hydrogen generation device 1, or a fuel cell application, such as an FCV (Fuel Cell Vehicle) that uses a fuel cell. The control unit 112 also receives information from an engine unit 103 of the hydrogen generation device 1 via a signal receiving unit 115. Examples of the information from the engine unit 103 include the amount of hydrogen detected by a flow rate sensor 32 provided in the hydrogen recovery device 31, and information from remaining amount detection sensors 11a, 12a, and 22a provided in the hydrogen carrier storage case 11, powder coating device 12, and liquid discharge device 22.

[0067] The remaining amount detection sensor 11a is provided in the hydrogen carrier accommodating case 11 and is a sensor that detects the remaining amount of the hydrogen carrier in the hydrogen carrier accommodating case 11. The remaining amount detection sensor 12a is provided in the powder coating device 12 and is a sensor that detects the remaining amount of the hydrogen carrier in the powder coating device 12. The remaining amount detection sensor 22a is provided in the liquid ejection device 22 and is a sensor that detects the remaining amount of liquid, including water, in the liquid ejection device 22.

[0068] Furthermore, the control unit 112 transmits, via the signal transmitting unit 114, a supply signal to the hydrogen carrier storage case 11, a drive signal for the powder coating device 12 and the liquid ejection device 22, a drive signal for the conveyor belt 41, etc., as signals generated based on pre-programmed control information.

[0069] The hydrogen carrier storage case 11 has a drive unit 11b for supplying the hydrogen carrier to the powder coating device 12. The powder coating device 12 has a drive unit 12b for coating the hydrogen carrier onto the conveyor belt 41. The liquid discharge device 22 has a drive unit 22b for discharging liquid onto the hydrogen carrier on the conveyor belt 41. Furthermore, the conveyor belt 41 is driven by the drive unit 41b as described above. The control unit 112 controls the driving of these drive units 11b, 12b, 22b, 41b.

[0070] Specifically, the drive unit 11b of the hydrogen carrier accommodating case 11 is, for example, a motor or a solenoid that drives a shutter provided at the connection between the hydrogen carrier accommodating case 11 and the powder coating device 12. The control unit 112 starts and stops the supply of the hydrogen carrier from the hydrogen carrier accommodating case 11 to the powder coating device 12, for example, by driving the drive unit 11b to open and close the shutter.

[0071] The driving unit 12b of the powder coating device 12 is, for example, a motor that drives a roller for coating the hydrogen carrier on the conveyor belt 41. The control unit 112 drives the driving unit 12b to control the driving of the roller, thereby starting and stopping the application of the hydrogen carrier from the powder coating device 12 to the surface 41a of the conveyor belt 41.

[0072] The drive unit 22b of the liquid discharger 22 is for discharging liquid onto the conveyor belt 41, for example, and the drive configuration differs depending on the method. The control unit 112 controls the driving of the drive unit 22b, thereby starting and stopping the discharge of liquid from the liquid discharger 22 onto the surface 41a of the conveyor belt 41. The control unit 112 also controls the amount of liquid that the liquid discharger 22 applies to the hydrogen carrier.

[0073] As described above, the drive unit 41b of the conveyor belt 41 is, for example, a motor. The control unit 112 controls the drive of the drive unit 41b to drive and stop the conveyor belt 41 and further to control the drive speed.

[0074] [Detailed configuration of the liquid ejection device] Next, the detailed configuration of the liquid discharger 22 will be described with reference to Figs. 3(a) to 5. Here, as a method for producing hydrogen, sodium borohydride may be dissolved in water and used. However, in this method, a larger amount of water is required than the amount of water theoretically indicated by the reaction formula, and this poses a problem of a decrease in the actual volumetric energy density. In addition, it is unavoidable that hydrogen is generated little by little during storage as an aqueous solution, which also reduces the volumetric energy density. For this reason, a hydrogen generating device capable of generating hydrogen while suppressing the decrease in volumetric energy density is desired.

[0075] For this reason, in this embodiment, a solid hydrogen carrier is used, and as described above, the liquid ejection device 22 ejects a liquid containing water in the form of droplets. Specifically, an inkjet system used in inkjet printers and the like is used as the liquid ejection device 22. Note that, although an inkjet head is used as the liquid ejection device 22 below, this includes those having a similar configuration even if they are not actually used in inkjet heads. In other words, those having a similar configuration even if they are not necessarily manufactured for inkjet printers are also included in the inkjet heads described below.

[0076] By using an inkjet head as the liquid ejection device 22, it is possible to apply the water-containing liquid to the hydrogen carrier in the form of minute droplets. As a result, when applying the same amount of liquid, the contact area between the hydrogen carrier and the water-containing liquid is increased compared to other methods, so that the reaction rate can be increased and hydrogen can be generated while suppressing a decrease in the volumetric energy density. In addition, by ejecting the water-containing liquid in the form of droplets, the amount of the water-containing liquid can be controlled very accurately, so that only the required amount of hydrogen can be generated when required.

[0077] Furthermore, by discharging the water-containing liquid in droplets, the water-containing liquid can be applied very thinly over a wide area, which makes it possible to suppress the generation of bubbles during hydrogen generation. If bubbles are generated, they may reach the hydrogen recovery path, causing contamination, i.e., impurities may be mixed into the recovered hydrogen. In addition, the hydrogen outlet may be blocked by the bubbles. Furthermore, if the inside of the device is filled with bubbles, the bubbles will adhere to the device. If the bubbles adhere to the device, for example, in the next process of generating hydrogen, the bubbles may hinder the application of the hydrogen carrier or the discharge of the water-containing liquid.

[0078] Two or more types of water-containing liquid can be mounted on the inkjet head. The water-containing liquid may be supplied to the inkjet head from a liquid storage unit (not shown) provided in the hydrogen generation device 1 via a tube or the like. By using the inkjet method, the ratio and amount of the two or more types of liquid applied can be accurately controlled. This allows the total composition of the water-containing liquid applied to the hydrogen carrier to be changed, making it possible to promote or suppress hydrogen generation.

[0079] The inkjet head can be either a thermal type head or a piezoelectric type head. As shown in FIG. 3(a), a thermal type head 220 has a heater 222 disposed in a flow path 221 filled with a liquid including water, and discharges liquid 224 by generating bubbles 223 by heating the heater 222. That is, the thermal type head 220 has a heater (heat transfer element) 222 mounted on a recording element substrate as a discharge element for discharging liquid. Then, bubbles 223 are generated by heat generated by the heater 222, and liquid 224 is discharged from a nozzle 225.

[0080] As shown in Fig. 3(b), the piezoelectric head 220A has a piezoelectric element 222A disposed in a flow path 221A filled with a liquid including water, and discharges liquid 224 by applying a voltage to the piezoelectric element 222A. That is, the piezoelectric head 220A has a piezoelectric element (piezoelectric element) 222A mounted on a recording element substrate as a discharge element for discharging liquid, and generates pressure by vibration of the piezoelectric element 222A, as shown exaggeratedly by the solid and dashed lines in Fig. 3(b), to discharge liquid 224 from a nozzle 225A.

[0081] Both types of heads have nozzles 225, 225A that eject liquid in droplets. Therefore, as described above, the contact area between the hydrogen carrier and the water-containing liquid can be increased to increase the reaction rate, and hydrogen can be generated while suppressing a decrease in volumetric energy density. In addition, the thermal type head has a small actuator part, so the device can be made smaller. The piezoelectric type head can control the size of the droplets of the water-containing liquid by controlling the displacement amount of the actuator part, so the hydrogen generation rate can be changed.

[0082] In addition, the inkjet head may be either the line type inkjet head 23 shown in FIG. 4 or the serial type inkjet head 24 shown in FIG. 5. The line type inkjet head 23 has a housing unit 23a equipped with a plurality of recording element substrates for discharging liquid, and discharges liquid across the entire width of the target without movement. The serial type inkjet head 24 has a housing unit 24a equipped with a recording element substrate for discharging liquid mounted on a carriage (not shown), and discharges liquid while scanning the target in the width direction. In the present embodiment, the "width direction" is the width direction of the conveyor belt 41 that intersects with the rotation direction of the conveyor belt 41 (orthogonal in this embodiment). By using the line type inkjet head 23, a carriage mechanism is not required, making it possible to generate hydrogen at high speed. By using the serial type inkjet head 24, it is possible to reduce the size of the device.

[0083] The line type inkjet head 23 has a supply path for supplying the water-containing liquid to the line type inkjet head 23, which is connected to the liquid storage case 21 in FIG. 1. The line type inkjet head 23 can dispense only one type of water-containing liquid. When dispensing multiple types of water-containing liquid, a partition is provided in the liquid storage case 21 so that the multiple types of water-containing liquid do not mix, and multiple liquid supply paths to the line type inkjet head 23 are also prepared so that the water-containing liquids do not mix. If a flow path is provided in the nozzle of the line type inkjet head 23 so that the liquids do not mix, it is possible to dispense multiple types of water-containing liquid in any amount. When dispensing multiple types of water-containing liquid, it is possible to provide multiple liquid storage cases 21 and multiple line type inkjet heads 23, and dispense multiple types of water-containing liquid in any amount.

[0084] An electrical control unit that transmits power and ejection control signals is electrically connected to the line-type inkjet head 23. The electrical signal path to the line-type inkjet head 23 is the same as the electrical signal path to the liquid ejection device 22 shown in FIG.

[0085] The serial type inkjet head 24 has a supply path for supplying the water-containing liquid to the serial type inkjet head 24 connected to the liquid storage case 21 in FIG. 1. The serial type inkjet head 24 can also dispense only one type of water-containing liquid. When dispensing multiple types of water-containing liquid, a partition is provided in the liquid storage case 21 to prevent the multiple types of water-containing liquid from mixing, and multiple liquid supply paths to the serial type inkjet head 24 are also provided to prevent the water-containing liquid from mixing. If a flow path is provided in the nozzle of the serial type inkjet head 24 so that the liquids do not mix, it is also possible to dispense multiple types of water-containing liquid in any amount.

[0086] The serial type inkjet head 24 uses a so-called ink tank used in an inkjet printer as the liquid storage case 21, and can also dispense liquids containing multiple types of water by storing them in multiple ink tanks.

[0087] An electrical control unit that transmits power and ejection control signals is electrically connected to the serial inkjet head 24. The electrical signal path to the serial inkjet head 24 is the same as the electrical signal path to the liquid ejection device shown in FIG.

[0088] In this embodiment, the liquid ejection device 22 preferably ejects the water-containing liquid in droplets to the hydrogen carrier with a volume of 100 pl (picoliters) or less. The liquid ejected by the liquid ejection device 22 is preferably 20 pl or less. By ejecting the liquid at 100 pl or less, the contact area between the hydrogen carrier and the water-containing liquid increases, thereby increasing the reaction rate. In addition, the water-containing liquid can be applied very thinly over a wide area, thereby suppressing the generation of bubbles during hydrogen generation.

[0089] In this embodiment, it is possible to most efficiently recover hydrogen by providing 2 moles of water to 1 mole of sodium borohydride using the above-mentioned liquid discharger 22. Therefore, it is desirable that the molar ratio of the amount of water provided by the liquid discharger 22 to sodium borohydride is about 1:2.

[0090] The amount of sodium borohydride can be changed by the supply amount from the powder coating device 12 and the conveying speed of the conveyor belt 41. The amount of sodium borohydride that reaches the liquid ejection device 22 is calculated from the supply amount and the conveying speed to control the amount of liquid containing water. Note that the liquid applied from the dispenser to the sodium borohydride is not limited to water (pure water), but may be an aqueous solution in which a water-soluble acidic substance or a water-soluble basic substance is dissolved, an aqueous solution in which a water-soluble organic solvent is dissolved, or a buffer solution that stabilizes the pH at a constant value.

[0091] In this embodiment, the liquid containing water is ejected in the form of droplets by the liquid ejection device 22 onto the hydrogen carrier, thereby increasing the contact area between the hydrogen carrier and the liquid containing water, thereby increasing the reaction rate and making it easier to promote the reaction between the hydrogen carrier and the liquid containing water on the conveyor belt 41.

[0092] By using an inkjet head as the liquid ejection device 22, small droplets of a few picoliters can be applied to the hydrogen carriers, increasing the contact area between the hydrogen carriers and the water-containing liquid, and allowing the reaction to occur quickly. Also, since the water-containing liquid can be applied only to the places on the conveyor belt 41 where the hydrogen carriers are present, no water is wasted and a decrease in energy density can be suppressed. Furthermore, since on-off control is easy, water is applied only when hydrogen is needed, and hydrogen can be obtained quickly.

[0093] The liquid applied from the liquid discharger 22 to the sodium borohydride is not limited to water (pure water), but may be an aqueous solution in which a water-soluble acidic substance or a water-soluble basic substance is dissolved, or an aqueous solution in which a water-soluble organic solvent is dissolved, or may be a buffer solution that stabilizes the pH at a constant value.

[0094] In the above description, an inkjet head is used as the liquid ejection device 22, but other configurations such as a dispenser may also be used.

[0095] <Second embodiment> The second embodiment will be described with reference to Fig. 6. The hydrogen generation device 1A of this embodiment differs from the first embodiment in that, in addition to the liquid discharge device (first liquid application device) 22, a liquid application device (second liquid application device) 26 capable of supplying a liquid containing water to the conveyor belt 41 is installed upstream of the powder coating device 12 in the rotation direction of the conveyor belt 41. Since the other configurations and functions are the same as those of the first embodiment described above, the same reference numerals are used for the similar configurations, and the description and illustrations are omitted or simplified, and the following description will focus on the points that are different from the first embodiment.

[0096] A gravure offset roller is used as the liquid application device 26. The gravure offset roller is a rubber roller used in offset printing and gravure printing. As described above, the liquid application device 26 is installed upstream of the powder coating device 12 in the rotation direction of the conveyor belt 41. In particular, the liquid application device 26 is arranged so as to supply a liquid containing water to a portion of the outer circumferential surface of the conveyor belt 41 that is stretched around the driven roller 43. The control unit 112 controls the amount of liquid that the liquid application device 26 applies to the hydrogen carrier.

[0097] This allows a liquid containing water to be applied to the conveyor belt 41 before the powder is applied. By providing the liquid application device 26 before the powder application device 12, it is possible to prevent the conveyor belt 41 from becoming charged. As a result, it is possible to prevent the hydrogen carrier powder from scattering inside the device and the hydrogen carrier powder from being mixed into the hydrogen recovery device 31. It is preferable that the amount of water applied in advance by the gravure offset roller is as small as possible.

[0098] The amount of the liquid containing water is the sum of the amount applied by the liquid applying device 26 and the amount applied by the liquid ejecting device 22. In order to carry out the same reaction as in the first embodiment, by applying 2 mol of the liquid containing water to 1 mol of sodium borohydride, sodium borohydride reacts without excess or deficiency, and hydrogen can be most efficiently recovered. Therefore, it is desirable that the molar ratio of the amount of water applied to sodium borohydride is about 1:2. The liquid applied to sodium borohydride from the liquid ejecting device 22 and the liquid applying device 26 is not limited to water (pure water), but may be an aqueous solution in which a water-soluble acidic substance or a water-soluble basic substance is dissolved, or may be an aqueous solution in which a water-soluble organic solvent is dissolved. It may also be a buffer solution that stabilizes the pH at a constant value.

[0099] <Third embodiment> The third embodiment will be described with reference to Fig. 7. The hydrogen generation device 1B of this embodiment differs from the first embodiment in that a temperature adjustment device 25 is provided in the liquid discharge device 22. Since the other configurations and functions are similar to those of the first embodiment described above, the same reference numerals are used for similar configurations, and explanations and illustrations are omitted or simplified. The following description will focus on the points that are different from the first embodiment.

[0100] In this embodiment, a temperature adjustment device 25 is installed outside the liquid ejection device 22. The temperature adjustment device 25 is a ceramic heater. A thermometer is provided inside the temperature adjustment device 25. The control unit 112 (see FIG. 2) controls the temperature adjustment device 25 based on a detection signal from the thermometer to adjust the temperature of the liquid inside the liquid ejection device 22 to within a predetermined temperature range. The predetermined temperature range is higher than 0°C and equal to or lower than 80°C.

[0101] The temperature adjustment device 25 may be a combination of a heater and a cooler, and the temperature of the liquid inside the liquid ejection device 22 may be adjusted to a predetermined temperature range by PID control of these. The temperature adjustment device 25 may be installed inside the liquid ejection device 22. Furthermore, the temperature adjustment device 25 may be installed inside or outside the liquid containing case 21. Furthermore, a thermometer for adjusting the temperature may be installed inside or outside the liquid ejection device 22.

[0102] In this embodiment, the liquid inside the liquid discharger 22 is adjusted to a predetermined temperature range by the temperature regulator 25, so that it is possible to apply a heated liquid containing water to the hydrogen carrier. This increases the reaction rate between the hydrogen carrier and the liquid containing water, and hydrogen generation can occur quickly. This allows hydrogen to be obtained quickly when needed. In addition, since the reaction between sodium borohydride and water is an exothermic reaction, when hydrogen is generated, the conveyor belt 41 in the hydrogen generator 1 is heated. At this time, a desired hydrogen generation rate can be obtained by controlling the temperature of the liquid containing water.

[0103] <Fourth embodiment> The fourth embodiment will be described with reference to Figures 1 and 5. In this embodiment, the liquid ejection device 22 is capable of ejecting liquid containing two or more types of water with different pH values. Since the other configurations and functions are similar to those of the first embodiment described above, the same reference numerals are used for similar configurations, and explanations and illustrations are omitted or simplified. The following description will focus on the points that are different from the first embodiment.

[0104] In the first to third embodiments described above, the reaction is controlled mainly by the amount of liquid applied to the hydrogen carrier. In contrast, in this embodiment, hydrogen can be obtained at a desired reaction rate by changing the pH of the applied liquid. For this reason, in this embodiment, it is preferable to use the serial type inkjet head 24 described in FIG. 5 as the liquid ejection device 22. A partition is provided in the liquid containing case 21 to prevent the two types of liquid containing water from mixing, and the water used in the first embodiment and a 30% aqueous solution of citric acid are poured into the liquid containing case 21 so as not to mix.

[0105] In addition, two liquid supply paths are provided from the liquid storage case 21 to the serial type inkjet head 24, and a flow path is provided that prevents the liquids from mixing even in the nozzles of the serial type inkjet head 24. This makes it possible to dispense two types of liquid in any desired amount.

[0106] By applying only the citric acid aqueous solution to the hydrogen carrier, the reaction rate with the hydrogen carrier can be increased, so that hydrogen generation can occur quickly. In addition, after hydrogen generation begins, the desired hydrogen generation rate can be obtained by controlling the ratio of the liquid containing water and the citric acid aqueous solution applied. The control of applying two types of liquid, water and the citric acid aqueous solution, can be performed by applying only water, applying water and the citric acid aqueous solution, or applying only the citric acid aqueous solution.

[0107] In addition to the above configuration, a 5% aqueous solution of sodium hydroxide may be prepared and applied. By applying only the aqueous sodium hydroxide solution to the hydrogen carrier, the reaction rate with the hydrogen carrier can be reduced, and the hydrogen generation rate can be slowed or stopped. This allows a desired hydrogen generation rate to be obtained. The control for arbitrarily applying three types of liquid, water, citric acid solution, and sodium hydroxide solution, is either applying only water, applying water and citric acid solution, applying only citric acid solution, applying water + sodium hydroxide solution, or applying only sodium hydroxide solution.

[0108] Furthermore, in the above configuration, a 100 mM phosphate buffer solution with a pH of 6.5 can be used instead of water. When using only water, the pH of the water may change depending on the external environment, such as the carbon dioxide concentration, but by using a buffer solution to stabilize the pH, a desired hydrogen generation rate can be obtained. [Explanation of symbols]

[0109] 1, 1A, 1B... Hydrogen generator 12 Powder coating device (coating device) 22 Liquid ejection device (first liquid application device) 23 Line type inkjet head 24 Serial type inkjet head 25...Temperature adjustment device 26 Liquid application device (second liquid application device) 31 Hydrogen recovery device 41....Conveyor belt (conveyor member) 41a...Surface 61... By-product recovery device (solid product recovery device) 112 Control section 220, 220A... Head 221...Flow path 222 Heater 222A···Piezo element 223... Bubbles 224...Liquid 225, 225A... Nozzle

Claims

1. a first liquid applying device that applies a liquid containing at least water to the solid hydrogen carrier; a control unit that controls the amount of the liquid that the first liquid-dispensing device dispenses onto the hydrogen carrier, The first liquid application device has a nozzle that ejects the liquid in the form of droplets. A hydrogen generating device characterized by:

2. A hydrogen recovery device is provided for recovering hydrogen generated by the reaction between the hydrogen carrier and the liquid.

2. The hydrogen generating apparatus according to claim 1.

3. A transport member capable of transporting the hydrogen carrier is provided.

2. The hydrogen generating apparatus according to claim 1.

4. A coating device for coating the hydrogen carrier on the transport member is provided.

4. The hydrogen generating apparatus according to claim 3.

5. a solid product recovery device for recovering a solid product generated by the reaction between the hydrogen carrier and the liquid on the transport member; 4. The hydrogen generating apparatus according to claim 3.

6. The hydrogen carrier is a metal hydride 2. The hydrogen generating apparatus according to claim 1.

7. The hydrogen carrier is sodium borohydride 2. The hydrogen generating apparatus according to claim 1.

8. The first liquid application device is an inkjet head.

2. The hydrogen generating apparatus according to claim 1.

9. The first liquid applying device has a heater disposed in a flow path filled with the liquid, and discharges the liquid by generating bubbles by heating the heater.

2. The hydrogen generating apparatus according to claim 1.

10. The first liquid applying device has a piezoelectric element disposed in a flow path filled with the liquid, and applies a voltage to the piezoelectric element to eject the liquid.

2. The hydrogen generating apparatus according to claim 1.

11. The first liquid application device ejects the liquid in the form of droplets of 100 pl or less.

2. The hydrogen generating apparatus according to claim 1.

12. The first liquid application device ejects the liquid in the form of droplets of 20 pl or less.

2. The hydrogen generating apparatus according to claim 1.

13. The apparatus further includes a temperature adjusting device that adjusts the temperature of the liquid inside the first liquid applying device to a temperature higher than 0°C and not higher than 80°C.

2. The hydrogen generating apparatus according to claim 1.

14. The first liquid applying device is capable of applying two or more types of liquids having different pH values.

2. The hydrogen generating apparatus according to claim 1.

15. One of the two or more liquids contains an acidic substance.

15. The hydrogen generating apparatus according to claim 14.

16. One of the two or more liquids contains a basic substance.

15. The hydrogen generating apparatus according to claim 14.

17. The hydrogen carrier is applied to the transport member by the application device. The hydrogen carrier is applied to the transport member by the application device.

5. The hydrogen generating device according to claim 4.

18. The control unit controls the amount of the liquid that the second liquid-donating device deposits onto the hydrogen carrier.

18. The hydrogen generating apparatus according to claim 17.

19. a liquid applying device that applies a liquid containing water to the solid hydrogen carrier; a hydrogen recovery device that recovers hydrogen generated by the reaction between the hydrogen carrier and the liquid, The liquid applying device applies the liquid in droplets toward the hydrogen carrier. A hydrogen generating device characterized by:

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