Hydrogen generating device

Abstract

A hydrogen generation device (1) is provided with: a liquid discharge means (22) that supplies a liquid containing at least water to a solid hydrogen carrier; and a controller that controls the amount of the liquid supplied to the hydrogen carrier by the liquid discharge device 22. As a result, it is possible to obtain a hydrogen generation device (1) that easily promotes a reaction between the hydrogen carrier and the aqueous 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, and the hydrogen carrier has the property of generating hydrogen when an aqueous liquid is poured thereon. Background Art

[0002] As a hydrogen generation device, a device that supplies water and a solvent to sodium borohydride and generates hydrogen by hydrolysis of sodium borohydride has been proposed (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] The above Patent Document 1 does not describe a specific structure indicating how to supply water and a solvent to sodium borohydride. As a hydrogen generation device, it is desired that the hydrolysis reaction with a hydrogen carrier such as sodium borohydride proceeds stably.

[0005] An object of the present invention is to provide a hydrogen generation device that easily promotes 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 first liquid supply device configured to supply a liquid containing at least water to a solid hydrogen carrier; and a controller configured to control the amount of the liquid supplied to the hydrogen carrier by the first liquid supply device.

[0007] In addition, the hydrogen generation device of the present invention includes: a liquid supply device configured to supply an aqueous liquid to a solid hydrogen carrier; and a hydrogen collection device configured to collect hydrogen generated by the reaction between the hydrogen carrier and the liquid, wherein the liquid supply device supplies the liquid to the hydrogen carrier in the form of droplets. Advantageous Effects 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 an aqueous liquid. Brief Description of the Drawings

[0009] Figure 1 is a schematic cross-sectional view of the structure of the hydrogen generation device according to the first embodiment. Figure 2 is a control block diagram of the hydrogen generation device according to the first embodiment. Figure 3AIt is a schematic cross-sectional view of a thermal inkjet head. Figure 3B It is a schematic cross-sectional view of a piezoelectric inkjet head. Figure 4 It is a schematic cross-sectional view of a line inkjet head. Figure 5 It is a schematic cross-sectional view of a serial inkjet head. Figure 6 It is a schematic cross-sectional view of a hydrogen generation device according to a second embodiment. Figure 7 It is a schematic cross-sectional view of a hydrogen generation device according to a third embodiment. Detailed Description <First Embodiment>

[0010] The following will refer to Figures 1 to 5 to describe the first embodiment. First, as an energy source to replace 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 (700 times the atmospheric pressure).

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

[0012] Therefore, various materials have been considered as materials (i.e., hydrogen carriers) that can carry hydrogen at a higher energy density than a hydrogen tank. 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 of 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 the theory represented by the reaction formula, thus reducing the substantial volumetric 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 1 of the present embodiment is a device that places a solid hydrogen carrier (powder in the present embodiment) on a conveyor belt 41 (on a conveying member), discharges an aqueous liquid onto it, and causes the hydrogen carrier on the conveyor belt 41 to react with the aqueous liquid to generate hydrogen. The hydrogen generation device 1 mainly includes a conveyor belt 41, a powder coating device 12 serving as a coating device, a liquid discharge device 22 serving as a discharge device, a hydrogen collection device 31, and a by-product collection device 61.

[0016] The conveyor belt 41 rotates in the direction of the arrow in Figure 1 The powder coating device 12 receives the supply of the hydrogen carrier from the hydrogen carrier storage tank 11 storing the hydrogen carrier in powder form and coats the hydrogen carrier on the surface 41a of the conveyor belt 41. In the rotation direction of the conveyor belt 41, the liquid discharge device 22 is provided downstream of the powder coating device 12, receives the supply of the liquid from the liquid storage tank 21 storing the aqueous liquid, and discharges the liquid onto the hydrogen carrier coated on the surface 41a of the conveyor belt 41.

[0017] In the rotation direction of the conveyor belt 41, the hydrogen collection device 31 is provided downstream of the liquid discharge device 22 and collects the hydrogen generated from the reaction between the hydrogen carrier and the liquid on the surface 41a of the conveyor belt 41. The by-product collection device 61 collects the by-products generated from the reaction between the hydrogen carrier and the liquid on the surface 41a of the conveyor belt 41. The by-products mentioned here refer to products other than hydrogen generated from the reaction between the hydrogen carrier and the liquid. In addition, the hydrogen generation device 1 of the present embodiment further includes a heating device 51 for heating the conveyor belt 41. It should be noted that the heating device 51 can be omitted.

[0018] The hydrogen generation device 1 can perform a series of steps on the conveyor belt 41, such as generating hydrogen by the reaction between the hydrogen carrier and the aqueous liquid, and collecting the by-products after the reaction. Therefore, the advantage of being able to continuously, stably, and long-term generate hydrogen is achieved in a compact device configuration.

[0019] The operation of the hydrogen generation device 1 is as follows. First, the conveyor belt 41 starts to move, and the heating device 51 starts heating at the same time. When the conveying speed of the conveyor belt 41 stabilizes at a predetermined speed and the surface temperature of the conveyor belt 41 reaches the set temperature, the powder coating device 12 starts to operate to coat the hydrogen carrier on the conveyor belt 41. When the hydrogen carrier reaches the position below the liquid discharge device 22, the liquid is discharged from the liquid discharge device 22, the reaction between the hydrogen carrier and the liquid starts, and the generated hydrogen is collected by the hydrogen collection device 31. It should be noted that in the case where the hydrogen generation device 1 does not include the heating device 51, the hydrogen carrier can be coated on the conveyor belt 41 regardless of the temperature of the conveyor belt 41.

[0020] Then, the by-products generated after the reaction between the hydrogen carrier and the aqueous liquid are transferred to the by-product collection device 61, and the by-product collection device 61 collects and sends the by-products to the by-product collection box 62. Next, each component will be described in detail. [Hydrogen Carrier]

[0021] The "hydrogen carrier" mentioned in this 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.

[0022] As the hydrogen carrier, sodium borohydride is preferably used. This is because the proportion 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, since the hydrogen generation reaction proceeds at a low temperature close to room temperature, hydrogen can be effectively obtained, and it is not easy to cause a fire due to contact with water, so the risk of safety is low.

[0023] In addition, the hydrogen carrier of this embodiment is preferably a solid such as powder or granule, 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 preferable. 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, it is preferable to perform surface roughening, pore-forming treatment, etc. to increase the surface area and the contact area with the aqueous liquid.

[0024] In the present embodiment, sodium borohydride powder with an average particle size of 50 μm is used as a 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)

[0025] It is known that the reaction (chemical formula (1)) is promoted by a Raney catalyst, which is formed from a metal such as nickel, cobalt, or copper and an acidic solution such as citric acid or acetic acid. [aqueous liquid]

[0026] The "aqueous liquid" mentioned in the present embodiment is not particularly limited as long as the liquid reacts with the hydrogen carrier and generates hydrogen when poured. That is to say, the aqueous liquid can be simple water. Additionally, 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.

[0027] 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.

[0028] 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.

[0029] The aqueous liquid can contain water-soluble acidic substances. 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 hydrogen generation rate 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 to these.

[0030] The aqueous liquid may include a water-soluble basic substance. The 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 production rate of hydrogen 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 production rate can be reduced. Examples thereof include alkalis such as sodium hydroxide, potassium hydroxide, and ammonia water, but are not limited thereto.

[0031] 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 production rate of hydrogen 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.

[0032] In addition to the above components, if necessary, the aqueous liquid may further contain various additives such as defoaming agents, pH regulators, viscosity regulators, rust inhibitors, preservatives, antifungal agents, antioxidants, and anti-reducing agents. [Catalyst]

[0033] As a catalyst material that can be used in combination with the hydrogen carrier, the following can be used: platinum group such as platinum Pt, ruthenium Ru, rhodium Rh, palladium Pd, osmium Os, or iridium Ir, Raney catalysts formed of metals such as cobalt Co, nickel Ni, and copper Cu, fluorinated hydrogen-absorbing alloys, etc. It is preferable to form the catalyst so that its surface area is large. For example, a structure in which the catalyst material is supported on a porous material such as γ-alumina or α-alumina, carbon powder, etc. can be adopted. The production rate of hydrogen can be adjusted by increasing the contact area between the hydrogen carrier and the catalyst material. [Desiccant]

[0034] The hydrogen carrier reacts with the aqueous liquid to generate hydrogen. Therefore, by reacting with water in the external environment such as moisture in the air, a small amount of hydrogen can also be generated. This results in a decrease in the energy density. In addition, there are safety risks caused by accidental hydrogen generation, such as deformation and breakage of the device due to an increase in the internal pressure of the hydrogen carrier storage tank 11 and fire caused by hydrogen leakage to the outside.

[0035] A desiccant can be used to prevent this situation. The desiccant can be mixed with the hydrogen carrier. A bag containing the desiccant and permeable to air and water vapor can be sealed in the hydrogen carrier storage box 11. Additionally, a bag containing the desiccant can be attached to the hydrogen carrier storage box 11 without being mixed with the hydrogen carrier. As desiccants, calcium oxide (quicklime), calcium chloride, silica gel, molecular sieves, polyacrylic acid, silica-alumina gel, etc. can be mentioned, but the desiccant is not limited to the exemplary substances as long as the desiccant contributes to drying. [Temperature of the aqueous liquid]

[0036] The temperature of the aqueous liquid is preferably higher than 0 °C and equal to or lower than 80 °C. In the case of 0 °C or lower, the aqueous liquid partially freezes, so the concentration of the components of the aqueous liquid changes, and thus there is a possibility that the expected hydrogen production amount cannot be obtained. In contrast, in the case of a temperature higher than 80 °C, the evaporation of the aqueous liquid becomes more frequent, so the concentration of the components of the aqueous liquid changes, and thus there is a possibility that the expected hydrogen production amount cannot be obtained.

[0037] The hydrogen production rate can be adjusted by controlling the temperature of the aqueous liquid. In this case, the temperature of the aqueous liquid can be measured by a contact or non-contact thermometer (not shown) installed inside or outside the liquid storage tank 21 or the liquid discharge device 22. Additionally, the temperature of the aqueous liquid can be adjusted by using a temperature adjustment device (heating device, cooling device (not shown)) inside or outside the liquid storage tank 21 or the liquid discharge device 22. Furthermore, the temperature can be adjusted by natural heat dissipation, etc. [Amount of aqueous liquid relative to the hydrogen carrier]

[0038] The hydrogen production device 1 of the present embodiment controls the amount of aqueous liquid supplied to the hydrogen carrier, which will be described in detail below. The control of the supply amount is executed by a central control device (described later). By receiving signals from the hydrogen application of a fuel cell or the like supplied by the hydrogen production device 1, each device of the hydrogen production device 1, etc., the central control device controls the supply amount based on a pre-stored program.

[0039] For example, in the case of using sodium borohydride as the hydrogen carrier, hydrogen is generated by reaction with the aqueous liquid. The sodium borohydride after the reaction is converted into sodium metaborate. The chemical formula of this reaction is as shown in the chemical formula (1) described above.

[0040] According to the chemical formula (1), it is preferably controlled to supply an aqueous liquid containing 2 molar equivalents of water to 1 molar equivalent of sodium borohydride. This is because the energy density becomes the highest. However, in the case of increasing the reaction rate of sodium borohydride at the start of the hydrogen production reaction, for example, an aqueous liquid containing more than 2 molar equivalents of water is sometimes supplied because the reaction proceeds more in the case of more water.

[0041] Since it is also known that sodium metaborate exists in the form of a hydrate, in the case where an aqueous liquid containing more than 2 molar equivalents of water is provided, sodium metaborate still exists in the form of a hydrate after the reaction. Since sodium metaborate exists in the form of up to a tetrahydrate, in the case where an aqueous liquid containing 6 molar equivalents or less of water is provided, the sodium metaborate hydrate still exists after the reaction. In the case where an aqueous liquid containing 6 molar equivalents of water is provided, the water is in excess, and sodium metaborate tetrahydrate and water remain after the reaction. In order to avoid an excessive decrease in the energy density and considering a reduction in the amount of product collection after the reaction, it is preferable to provide an aqueous liquid containing more than 2 molar equivalents and less than 6 molar equivalents of water. [Conveyor belt]

[0042] The conveyor belt 41 serving as a conveying member is an endless belt and is capable of conveying 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 the driven roller 43 is subjected to a force that pushes the driven roller 43 toward the front surface side of the conveyor belt by the applied force of a biasing spring (not shown), and due to this force, a certain tension is applied to the conveyor belt 41. In addition, the driving roller 42 is connected to a driving unit 41b (see Figure 2 ) such as an electric motor, and thus, since the driving roller 42 is rotationally driven by the driving unit 41b, the conveyor belt 41 circulates (i.e., rotates) in the Figure 1 clockwise direction (arrow direction). Although the conveyor belt 41 is supported by two rollers in the present embodiment, there is no problem even if the conveyor belt 41 is supported by a plurality of rollers such as three rollers, for example.

[0043] In any case, the conveyor belt 41 is arranged such that the stretched surface stretched by two rollers (the driving roller 42 and the driven roller 43 in the present embodiment), that is, the above-mentioned surface 41a is oriented in a substantially horizontal direction. In addition, the surface 41a is an upward-facing surface, and the powder coating device 12, the liquid discharging device 22, and the hydrogen collecting device 31 provided above the conveyor belt 41 face the surface 41a.

[0044] The conveyor belt 41 configured in this way includes a mechanism for conveying the hydrogen carrier coated on the conveyor belt 41 by the powder coating device 12 in the order of the liquid discharging device 22 and the hydrogen collecting device 31 toward the downstream side in the rotation direction. Thereafter, the by-products after the reaction are further conveyed downstream to the by-product collecting device 61. In addition, a heating device 51 for heating the conveyor belt 41 from the inner peripheral surface side is provided on the inner side of the conveyor belt 41.

[0045] From the viewpoint of never causing static electricity, the conveyor belt 41 is preferably given conductivity and can be formed of metal or resin. In the case of metal, aluminum, iron, copper, Ni, stainless steel (SUS), etc. can be used. Further, in the case of resin, from the viewpoint of heat resistance, a resin having a high glass transition temperature is preferred, for example, an engineering plastic having high heat resistance and high durability is preferred, such as polyimide, polyamideimide, and polyetheretherketone. Further, in the case where the resin does not have conductivity, it is preferred that the resin contains an antistatic agent such as carbon black to impart conductivity. Further, from the viewpoint of thermal conductivity, the thickness of the conveyor belt 41 is preferably about 30 μm or more and 200 μm or less. In the present embodiment, an endless belt formed of a resin (which is a carbon-containing polyimide) having conductivity is used as the conveyor belt 41.

[0046] The conveying speed (rotational speed) of the conveyor belt 41 is a predetermined speed set for each hydrogen carrier and aqueous liquid used. Further, it is preferred that the conveying speed can be appropriately adjusted according to the required amount of hydrogen. Thus, for example, in the case where the amount of hydrogen collected by the hydrogen collection device 31 does not reach the planned amount, the hydrogen generation amount can be adjusted, for example, by appropriately adjusting the conveying speed according to the amount of hydrogen measured by a flow rate sensor 32 (see Figure 2 ), etc., which measures the flow rate of hydrogen collected by the hydrogen collection device 31. [Powder coating device]

[0047] The powder coating device 12 is a device that receives the supply of the hydrogen carrier from the hydrogen carrier storage tank 11 and coats the hydrogen carrier on the conveyor belt 41. If the thickness of the hydrogen carrier coated on the conveyor belt 41 is about 50 μm or more and 3 mm or less, there is no problem, but it is preferred to set the thickness to 50 μm or more and 500 μm or less in order to improve the reactivity with the aqueous liquid.

[0048] Further, the hydrogen carrier storage tank 11 serving as a hydrogen carrier supply container stores the hydrogen carrier (hydrogen carrier for replenishment) for replenishing the storage section of the powder coating device 12. The hydrogen carrier storage tank 11 can be attached to and detached from the powder coating device 12. That is, the hydrogen carrier storage tank 11 is replaceable. [Liquid discharge device]

[0049] The liquid discharge device (first liquid supply device) 22 is a liquid supply device that receives the supply of the aqueous liquid from the liquid storage tank 21 storing the aqueous liquid and supplies the aqueous liquid to the hydrogen carrier on the conveyor belt 41. The liquid discharge device 22 can adjust the amount of the aqueous liquid relative to the amount of the hydrogen carrier. The liquid discharge device 22 preferably discharges the liquid onto the conveyor belt 41 in a non-contact manner.

[0050] The non-contact liquid discharge device 22 has no particular problems as long as the liquid discharge device 22 is a device capable of supplying an aqueous liquid to the hydrogen carrier in the form of droplets, such as a spraying system, a dispenser system, or an inkjet system. By discharging the liquid onto the hydrogen carrier in the form of droplets, the contact area between the hydrogen carrier and the liquid can be increased, thereby increasing the reaction rate. In addition, the aqueous liquid can be provided in an extremely thin layer over a wide area, thus suppressing the generation of bubbles during hydrogen production.

[0051] In the non-contact liquid discharge device 22, the amount of the aqueous liquid relative to the hydrogen carrier can be adjusted. For example, the supply amount can be adjusted by adjusting the diameter and number of nozzles for supplying the aqueous liquid and the pressure applied to the liquid. In the case of a device including an electric controller, the supply amount can be adjusted by opening and closing the flow path of the aqueous liquid. The supply amount can be controlled based on information on the hydrogen production amount and an input from the outside.

[0052] The contact-type liquid supply device can be used in combination with the non-contact liquid discharge device. As the contact-type liquid supply device, an intaglio offset roller, a rod coater, a die coater, a knife coater, a blade coater, etc. can be mentioned. The contact-type liquid supply device can adjust the supply amount of the liquid by adjusting the roller type, the contact pressure on the belt on which the hydrogen carrier is to be placed, the contact pressure between the doctor blade and the roller, etc.

[0053] In addition, the liquid storage tank 21 serving as a liquid supply container stores the aqueous liquid to be supplied to the liquid discharge device 22. The liquid storage tank 21 can be attached to and detached from the liquid discharge device 22. That is, the liquid storage tank 21 is replaceable. [Hydrogen collection device]

[0054] A hydrogen collection device 31 is provided to collect hydrogen generated by the reaction between the hydrogen carrier and the aqueous liquid. As Figure 1 shown, in the sense of an exhaust device, it can be a canopy structure, or it can be a structure in which the upper outer wall of the hydrogen generation device 1 has an inclined shape and a discharge port is provided at the highest position. As long as the structure collects the hydrogen generated inside the hydrogen generation device 1, there are no particular problems. The hydrogen collection device 31 of the present embodiment is provided above the conveyor belt 41 and includes a collection part 31a that collects the hydrogen generated on the conveyor belt 41 and a suction fan 31b that sucks the hydrogen collected by the collection part 31a. The hydrogen sucked by the suction fan 31b is supplied to a supply destination, such as a fuel cell, through a pipe 31c.

[0055] In a fuel cell that serves as one of the destinations for hydrogen supply, dry hydrogen is desired. However, not only hydrogen but also water vapor or vapor of an alkaline substance generated by the reaction may be mixed into the collected gas. Therefore, it is preferable to provide a mechanism for removing substances other than hydrogen in a hydrogen flow path (such as pipe 31c), such as a filter containing water, a filter containing silica gel, a steam trap incorporating a cooling device, etc. [By-product collection device]

[0056] The function of the by-product collection device 61 that serves as a solid product collection device is to remove the by-products on the conveyor belt 41 from the conveyor belt 41 and send the by-products (solid products) to the by-product collection box 62. In the case where the hydrogen carrier is sodium borohydride, the by-product is, for example, sodium metaborate. The by-product collection device 61 includes a collection scraper 61a that contacts the conveyor belt 41 and a scraper holding member (not shown in the figure) that holds the collection scraper 61a.

[0057] The collection scraper 61a preferably adjoins the outer peripheral surface of the conveyor belt 41 stretched by the roller of the stretched conveyor belt 41. In this embodiment, the roller is the drive roller 42. Additionally, the collection scraper 61a preferably adjoins surfaces other than the surface 41a, such as the lower surface in the vertical direction or the side surface in the horizontal direction of the conveyor belt 41. Further, the by-product collection box 62 is preferably provided below the collection scraper 61a in the vertical direction. Thus, the by-products collected by the collection scraper 61a can fall by gravity and be collected by the by-product collection box 62.

[0058] The material of the collection scraper 61a is not particularly limited, and examples thereof include a rubber scraper formed of rubber and used for cleaning an intermediate transfer belt in a copying machine, etc. It is formed of rubber such as silicone rubber or polyurethane rubber and molded into a plate shape, and is connected such that its corners contact in the opposite direction to the moving direction of the conveyor belt 41, thereby removing the by-products on the conveyor belt 41. Additionally, there is no problem in using a scraper formed of metal or glass in a spatula shape (i.e., a so-called spatula) as the collection scraper 61a.

[0059] The scraper holding member has the function of supporting the collection scraper 61a and applying a certain pressure to the collection scraper 61a by the warping of the scraper holding member. Although its material is not particularly limited, metal is preferred because pressure is to be applied.

[0060] Additionally, the by-product collection box 62 that serves as a collection container is a box for collecting the by-products collected from the conveyor belt 41 by the collection scraper 61a. The by-product collection box 62 can be attached to the by-product collection device 61 and can be detached from it. That is, the by-product collection box 62 is replaceable. [Heating device]

[0061] The heating device 51 has a function of heating the conveyor belt 41 from the inner peripheral surface side to promote the reaction between the hydrogen carrier and the aqueous liquid and stably generate hydrogen. Therefore, in the hydrolysis reaction of the hydrogen carrier, hydrogen can be stably extracted without using a reaction promoter such as a catalyst.

[0062] In addition, the system for heating the conveyor belt 41 by the heating device 51 is a system with high energy efficiency in terms of heating compared to systems such as heating the hydrogen carrier or heating the aqueous liquid, because the range to be heated and the timing of heating can be executed only during the reaction between the hydrogen carrier and the aqueous liquid.

[0063] The heating device 51 can be a heating device that heats the conveyor belt 41 via a film or a belt, can be a heating device that directly transfers the heat of the heater to the conveyor belt 41, or can be a heating device that includes an induction heating system heater if the conveyor belt 41 is formed of metal. There is no particular limitation as long as heat can be quickly transferred to the conveyor belt 41 and the conveyor belt 41 can be quickly heated. In addition, there is no problem with a configuration in which a heater is provided on the outer peripheral surface side of the conveyor belt 41 and the hydrogen carrier and the aqueous liquid are directly heated. It should be noted that in the case of a configuration for heating from the outer peripheral surface side, from the viewpoint of safety, since contact between hydrogen and the heater should be avoided, a configuration for heating via a heating film or the like is preferred. [Central control device]

[0064] Figure 2 is a block diagram of the system of the hydrogen generation device 1 of the present embodiment. The central control device 101 includes: a controller 112, a random access memory (RAM) 111, a storage 113 that stores programs, a communication interface, a signal transmission unit 114, and a signal reception unit 115. The controller 112 is composed of a central processing unit (CPU) or a CPU and a read-only memory (ROM), and issues control commands for the entire hydrogen generation device 1 by executing the programs stored in the storage 113.

[0065] The RAM 111 is the main memory for the operation of the controller 112. The storage 113 is a storage area for storing control programs and the like, and the controller 112 processes by reading control programs, temporarily stored timing data, log information, etc. from the RAM 111 and the storage 113.

[0066] Information from an external application 102 is input into a controller 112. The external application is a fuel cell application such as a hydrogen application of a fuel cell supplied by a hydrogen generation device 1 or a fuel cell vehicle (FCV) using a fuel cell. In addition, the controller 112 receives information on an engine unit 103 of the hydrogen generation device 1 through a signal receiving unit 115. As information on the engine unit 103, mention may be made of: the amount of hydrogen detected by a flow sensor 32 provided in a hydrogen collection device 31, information from remaining amount detection sensors 11a, 12a, and 22a provided in a hydrogen carrier storage tank 11, a powder coating device 12, and a liquid discharge device 22, etc.

[0067] The remaining amount detection sensor 11a is a sensor provided in the hydrogen carrier storage tank 11 and detects the remaining amount of the hydrogen carrier in the hydrogen carrier storage tank 11. The remaining amount detection sensor 12a is a sensor provided in the powder coating device 12 and detects the remaining amount of the hydrogen carrier in the powder coating device 12. The remaining amount detection sensor 22a is a sensor provided in the liquid discharge device 22 and detects the remaining amount of the water-containing liquid in the liquid discharge device 22.

[0068] In addition, the controller 112 transmits the following signals as signals generated according to preset control information through a signal transmission unit 114: a replenishment signal to the hydrogen carrier storage tank 11, a drive signal to the powder coating device 12 and the liquid discharge device 22, a drive signal to a conveyor belt 41, etc.

[0069] The hydrogen carrier storage tank 11 includes a drive unit 11b for replenishing the powder coating device 12 with a hydrogen carrier. The powder coating device 12 includes a drive unit 12b for coating the hydrogen carrier on the conveyor belt 41. The liquid discharge device 22 includes a drive unit 22b for discharging a liquid onto the hydrogen carrier on the conveyor belt 41. In addition, the conveyor belt 41 is driven by a drive unit 41b as described above. The controller 112 controls the driving of the drive units 11b, 12b, 22b, and 41b.

[0070] Specifically, the drive unit 11b of the hydrogen carrier storage tank 11 is, for example, an electric motor or a solenoid, and the electric motor or solenoid drives a shutter provided at a connection portion between the hydrogen carrier storage tank 11 and the powder coating device 12. The controller 112 performs a replenishment operation of the hydrogen carrier from the hydrogen carrier storage tank 11 to the powder coating device 12 or stops the replenishment operation, for example, by driving the drive unit 11b to open and close the shutter.

[0071] The drive unit 12b of the powder coating device 12 is, for example, an electric motor that drives a roller to coat a hydrogen carrier on the conveyor belt 41. The controller 112 drives the drive unit 12b to control the drive of the roller, thereby performing and stopping the coating operation of coating the hydrogen carrier from the powder coating device 12 onto the surface 41a of the conveyor belt 41.

[0072] The drive unit 22b of the liquid discharging device 22 is, for example, a drive unit that discharges liquid onto the conveyor belt 41, and the drive structure varies according to its system. The controller 112 controls the drive of the drive unit 22b, thereby performing the liquid discharging operation from the liquid discharging device 22 onto the surface 41a of the conveyor belt 41 and its stop. In addition, the controller 112 controls the amount of liquid applied to the hydrogen carrier by the liquid discharging device 22.

[0073] The drive unit 41b of the conveyor belt 41 is, for example, the above-mentioned electric motor. The controller 112 controls the drive of the drive unit 41b, thereby driving and stopping the conveyor belt 41 and further controlling its driving speed. [Detailed Structure of Liquid Discharging Device]

[0074] Next, Figures 3A to 5 The detailed structure of the liquid discharging device 22 will be described. Here, as a method of hydrogen production, there is a case where sodium borohydride is used in a state dissolved in water. However, in the case of this method, a larger amount of water than the amount of water shown by the reaction formula theory is required, so there is a problem of a substantial decrease in the volumetric energy density. In addition, the situation where hydrogen is gradually generated during the storage of the aqueous solution cannot be avoided, and the volumetric energy density also decreases accordingly. Therefore, a hydrogen production device that can generate hydrogen while suppressing a decrease in the volumetric energy density is desired.

[0075] Therefore, in the present embodiment, a solid hydrogen carrier is used, and the liquid discharging device 22 is arranged to discharge the water-containing liquid in the form of droplets as described above. Specifically, an inkjet system used in an inkjet printer or the like is used as the liquid discharging device 22. It should be noted that although the case where an inkjet head is used as the liquid discharging device 22 will be described below, this includes cases where even if an inkjet head is not actually used, it has a similar structure. That is, the inkjet head described below also includes an inkjet head having a similar structure that is not necessarily manufactured for an inkjet printer.

[0076] By using an inkjet head as the liquid discharging device 22, the water-containing liquid can be supplied to the hydrogen carrier in the form of minute droplets. Thereby, in the case of supplying the same amount of liquid, compared with other systems, the contact area between the hydrogen carrier and the water-containing liquid increases, so the reaction rate can be increased, and hydrogen can be generated while suppressing a decrease in the volumetric energy density. In addition, by discharging the water-containing liquid in the form of droplets, the amount of the water-containing liquid can be very precisely controlled, so that the necessary amount of hydrogen can be generated at the necessary timing.

[0077] In addition, by discharging the aqueous liquid in the form of droplets, the aqueous liquid can be provided in an extremely thin layer over a wide area, thereby suppressing the generation of bubbles during hydrogen production. If bubbles are generated, there is a possibility that the bubbles may reach the path for collecting hydrogen or the like, resulting in contamination, that is, impurities may be mixed into the collected hydrogen. Further, when the inside of the apparatus is filled with bubbles, the bubbles adhere to the apparatus. When the bubbles adhere to the apparatus, for example, the bubbles may hinder the coating of the hydrogen carrier and the discharge of the aqueous liquid in the next step for hydrogen production.

[0078] Two or more kinds of aqueous liquids can be incorporated into the inkjet head. It should be noted that a configuration in which the aqueous liquid is supplied to the inkjet head from a liquid storage section (not shown) provided in the hydrogen production apparatus 1 through a tube or the like can be adopted. By adopting the inkjet system, the supply amounts and ratios of two or more kinds of liquids can be precisely controlled. Thereby, the total composition of the aqueous liquid to be provided to the hydrogen carrier can be changed, and thus the production of hydrogen can be promoted and suppressed.

[0079] As the inkjet head, a thermal inkjet head and a piezoelectric inkjet head can be selected. In the thermal inkjet head 220, as Figure 3A shown, a heater 222 is provided in a flow path 221 filled with the aqueous liquid, and the liquid 224 is discharged by generating bubbles 223 by heating with the heater 222. That is, in the thermal inkjet head 220, the heater (thermal conduction conversion element) 222 is mounted on the recording element board as a discharge element for discharging the liquid. Further, bubbles 223 are generated by the heat generation of the heater 222, and thereby the liquid 224 is discharged from the nozzle 225.

[0080] In the piezoelectric inkjet head 220A, as Figure 3B shown, a piezoelectric element 222A is provided in a flow path 221A filled with the aqueous liquid, and the liquid 224 is discharged by applying a voltage to the piezoelectric element 222A. That is, in the piezoelectric inkjet head 220A, the piezoelectric element (piezoelectric type element) 222A is mounted on the recording element board as a discharge element for discharging the liquid, and as Figure 3B shown in an enlarged manner by solid and dashed lines in, pressure is generated by the vibration of the piezoelectric element 222A, and thereby the liquid 224 is discharged from the nozzle 225A.

[0081] The inkjet head of each system includes a nozzle 225 or 225A that discharges the liquid in the form of droplets. Therefore, as described above, the contact area between the hydrogen carrier and the aqueous liquid can be increased to improve the reaction rate, and hydrogen can be produced while suppressing a decrease in the volume energy density. Further, the thermal inkjet head has a small actuator portion, and thus the apparatus can be miniaturized. The piezoelectric inkjet head can control the droplet size of the aqueous liquid by controlling the displacement amount of the actuator portion, and thereby the hydrogen production rate can be changed.

[0082] In addition, for the inkjet head, the line-type inkjet head 23 shown in Figure 4 and the serial inkjet head 24 shown in Figure 5 can be selected. In the line-type inkjet head 23, a plurality of recording elements for ejecting liquid are incorporated in the housing unit 23a, and the liquid is discharged onto the entire area of the target object in the width direction without moving. In the serial inkjet head 24, a housing unit 24a equipped with a recording element plate for discharging liquid is mounted on a carriage (not shown), and the liquid is discharged while moving in a scanning manner in the width direction with respect to the target object. In the case of this embodiment, the "width direction" is the width direction of the conveyor belt 41 that intersects (at a right angle in this embodiment) the rotation direction of the conveyor belt 41. By using the line-type inkjet head 23, a carriage mechanism is not required, and thus hydrogen can be generated at high speed. By using the serial inkjet head 24, the device can be miniaturized.

[0083] In the line-type inkjet head 23, a supply path for supplying the water-containing liquid to the line-type inkjet head 23 is connected to the Figure 1 liquid storage tank 21 therein. The line-type inkjet head 23 can also supply only one kind of water-containing liquid. In addition, in the case of supplying a plurality of water-containing liquids, a partition wall can be provided in the liquid storage tank 21 so that the plurality of water-containing liquids do not mix, and a plurality of liquid supply paths leading to the line-type inkjet head 23 can be provided so that the water-containing liquids do not mix. Furthermore, if the flow path inside the nozzle of the line-type inkjet head 23 is provided in a non-mixing manner, a plurality of water-containing liquids can be supplied in any supply amounts. In addition, in the case of supplying a plurality of water-containing liquids, by providing a plurality of liquid storage tanks 21 and a plurality of line-type inkjet heads 23, a plurality of water-containing liquids can be supplied in any supply amounts.

[0084] In addition, the line-type inkjet head 23 is electrically connected to an electric controller that transmits electric power and ejection control signals. The electric signal path leading to the line-type inkjet head 23 is similar to the Figure 2 electric signal path leading to the liquid ejection device 22 shown in.

[0085] In the serial inkjet head 24, a supply path for supplying the water-containing liquid to the serial inkjet head 24 is connected to the Figure 1 liquid storage tank 21 therein. The serial inkjet head 24 can also supply only one kind of water-containing liquid. In addition, in the case of supplying a plurality of water-containing liquids, a partition wall can be provided in the liquid storage tank 21 so that the plurality of water-containing liquids do not mix, and a plurality of liquid supply paths leading to the serial inkjet head 24 can be provided so that the water-containing liquids do not mix. Furthermore, if the flow path inside the nozzle of the serial inkjet head 24 is provided in a non-mixing manner, a plurality of water-containing liquids can be supplied in any supply amounts.

[0086] In the serial inkjet head 24, a so-called ink tank used in an inkjet printer can be used as the liquid storage tank 21, and a plurality of water-containing liquids can be loaded into the plurality of ink tanks for use and supply.

[0087] In addition, the serial inkjet head 24 is electrically connected to an electric controller that transmits electric power and discharge control signals. The electric signal path leading to the serial inkjet head 24 is similar to Figure 2 the electric signal path leading to the liquid discharge device shown.

[0088] In the present embodiment, the liquid discharge device 22 preferably discharges the water-containing liquid onto the hydrogen carrier in the form of droplets having a volume equal to or less than 100 pl (picoliters). In addition, the liquid discharged by the liquid discharge device 22 is preferably 20 pl or less. By setting the discharged liquid to 100 pl or less, the contact area between the hydrogen carrier and the water-containing liquid increases, so that the reaction rate can be increased. In addition, since the water-containing liquid can be provided in an extremely thin layer over a wide area, generation of bubbles during hydrogen generation can be suppressed.

[0089] In the present embodiment, by supplying 2 molar equivalents of water to 1 molar equivalent of sodium borohydride by the above-described liquid discharge device 22, the sodium borohydride reacts without excess or deficiency, and thus hydrogen can be collected with the highest efficiency. Therefore, the molar ratio of the amount of water provided by the liquid discharge device 22 to sodium borohydride is preferably about 1:2.

[0090] The amount of sodium borohydride can be changed according to the supply amount from the powder coating device 12 and the conveyance speed of the conveyor belt 41. The amount of the water-containing liquid is controlled by calculating the amount of sodium borohydride that has reached the position of the liquid discharge device 22 from the supply amount and the conveyance speed. It should be noted that the liquid supplied to sodium borohydride from the dispenser is not limited to water (pure water), and 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 near a certain value.

[0091] In the case of the present embodiment configured in this way, since the water-containing liquid is discharged onto the hydrogen carrier in the form of droplets by the liquid discharge device 22, the contact area between the hydrogen carrier and the water-containing liquid increases, so that the reaction rate can be increased, and the reaction between the hydrogen carrier and the water-containing liquid on the conveyor belt 41 can be easily promoted.

[0092] By using an inkjet head as the liquid discharge device 22, picoliter-sized droplets can be supplied to the hydrogen carrier, thereby increasing the contact area between the hydrogen carrier and the aqueous liquid and thus enabling the reaction to occur rapidly. Additionally, since the aqueous liquid can be selectively supplied to the position on the conveyor belt 41 where the hydrogen carrier is present, an excessive amount of water is not required, and a reduction in energy density can be suppressed. Furthermore, since on-off control is easy, water can be supplied only when hydrogen is needed, enabling hydrogen to be obtained rapidly.

[0093] It should be noted that the liquid supplied by the liquid discharge device 22 to sodium borohydride is not limited to water (pure water), and can 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 near a certain value.

[0094] In addition, although the case of using an inkjet head as the liquid discharge device 22 has been described, different elements such as a dispenser can be used. <Second Embodiment>

[0095] The second embodiment will be described by using Figure 6 The hydrogen generation device 1A of this embodiment is different from that of the first embodiment in that, in addition to the liquid discharge device (first liquid supply device) 22, a liquid supply device (second liquid supply device) 26 capable of supplying an aqueous liquid to the conveyor belt 41 is provided on the upstream side of the powder coating device 12 in the rotation direction of the conveyor belt 41. Other elements and functions are similar to those of the above-described first embodiment, so similar elements are denoted by the same reference numerals, and their descriptions and illustrations are omitted or simplified, and the parts different from the first embodiment will be mainly described.

[0096] A gravure offset roller is used as the liquid supply device 26. The gravure offset roller is a rubber roller and is used for offset printing and gravure printing. As described above, the liquid supply device 26 is provided on the upstream side of the powder coating device 12 in the rotation direction of the conveyor belt 41. In particular, the liquid supply device 26 is provided so as to supply an aqueous liquid to a part of the outer peripheral surface of the conveyor belt 41 that is stretched by the driven roller 43. The controller 112 controls the amount of the liquid supplied by the liquid supply device 26 to the hydrogen carrier.

[0097] Thereby, the aqueous liquid can be coated on the conveyor belt 41 before the powder is coated. By providing the liquid supply device 26 at a stage prior to the powder coating device 12, the conveyor belt 41 can be prevented from being charged. Thereby, the dispersion of the hydrogen carrier powder in the device and the mixing of the hydrogen carrier powder into the hydrogen collection device 31 can be prevented. It should be noted that it is more preferable that the amount of water pre-supplied by the gravure offset roller is small.

[0098] The amount of the aqueous liquid is the sum of the amount provided by the liquid supply device 26 and the amount provided by the liquid discharge device 22. Since a reaction similar to that of the first embodiment is carried out, by supplying 2 molar equivalents of water to 1 molar equivalent of sodium borohydride, the sodium borohydride reacts without excess or deficiency, enabling hydrogen to be collected with the highest efficiency. Therefore, the molar ratio of the water provided to sodium borohydride is preferably about 1:2. It should be noted that the liquid supplied to sodium borohydride from the liquid discharge device 22 and the liquid supply device 26 is not limited to water (pure water), and 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 near a certain value. <Third Embodiment>

[0099] The third embodiment will be described by using Figure 7 . The hydrogen generation device 1B of this embodiment is different from that of the first embodiment in that the liquid discharge device 22 is equipped with a temperature adjustment device 25. Other elements and functions are similar to those of the above-described first embodiment, so similar elements are denoted by the same reference numerals, and their descriptions and illustrations are omitted or simplified, and the parts different from the first embodiment will be mainly described.

[0100] In this embodiment, the temperature adjustment device 25 is installed outside the liquid discharge device 22. The temperature adjustment device 25 is a ceramic heater. In addition, a thermometer is provided inside the temperature adjustment device 25. The controller 112 (see Figure 2 ) controls the temperature adjustment device 25 based on the detection signal of the thermometer, thereby adjusting the temperature of the liquid in the liquid discharge device 22 to a predetermined temperature range. The predetermined temperature range is a range higher than 0 °C and equal to or lower than 80 °C.

[0101] It should be noted that the temperature adjustment device 25 may be a combination of a heater and a cooler, and by performing PID control on them, the temperature of the liquid in the liquid discharge device 22 can be adjusted to a predetermined temperature range. In addition, the temperature adjustment device 25 may be installed inside the liquid discharge device 22. Furthermore, the temperature adjustment device 25 may be provided inside or outside the liquid storage tank 21. In addition, a thermometer for temperature adjustment may be provided inside or outside the liquid discharge device 22.

[0102] In this embodiment, since the liquid in the liquid discharge device 22 is adjusted to a predetermined temperature range by the temperature adjustment device 25, the heated aqueous liquid can be supplied to the hydrogen carrier. Therefore, the reaction rate between the hydrogen carrier and the aqueous liquid can be increased, and thus hydrogen can be generated rapidly. Therefore, when hydrogen is required, hydrogen can be obtained rapidly. In addition, since the reaction between sodium borohydride and water is an exothermic reaction, the conveyor belt 41 in the hydrogen generation device 1 is heated when hydrogen is generated. At this time, by controlling the temperature of the aqueous liquid, a desired hydrogen generation rate can be obtained. <Fourth Embodiment>

[0103] The fourth embodiment will be described by using Figures 1 to 5 . In the case of this embodiment, the liquid discharge device 22 is capable of discharging two or more kinds of aqueous liquids having different pH values. Other elements and functions are similar to those of the first embodiment described above, and thus similar elements are denoted by the same reference numerals, and their descriptions and illustrations are omitted or simplified, and parts different from the first embodiment will be mainly described.

[0104] In the first to third embodiments described above, the reaction is mainly controlled by the supply amount of the liquid supplied to the hydrogen carrier. In contrast, in this embodiment, by changing the pH value of the supplied liquid, hydrogen can be obtained at a desired reaction rate. Therefore, in this embodiment, it is preferable to use the serial inkjet head 24 described with reference to Figure 5 as the liquid discharge device 22. A partition wall is provided in the liquid storage tank 21 so that the two aqueous liquids do not mix, and water and a 30% aqueous citric acid solution used in the first embodiment are charged into the liquid storage tank 21 so that they do not mix.

[0105] In addition, two liquid supply paths extending from the liquid storage tank 21 to the serial inkjet head 24 are provided, and a flow path for preventing mixing is also provided in the nozzles of the serial inkjet head 24. Thereby, the two liquids can be applied in any supply amount.

[0106] By supplying only the aqueous citric acid solution to the hydrogen carrier, the reaction rate with the hydrogen carrier can be increased, and thus hydrogen can be generated rapidly. In addition, after hydrogen generation starts, by controlling the supply ratio of the aqueous liquid and the aqueous citric acid solution, a desired hydrogen generation rate can be obtained. The control of arbitrarily supplying the two liquids of water and the aqueous citric acid solution is any of the following: supplying only water, supplying water and the aqueous citric acid solution, and supplying only the aqueous citric acid solution.

[0107] In addition to the above configuration, a 5% aqueous sodium hydroxide solution can also be prepared and used for supply. By supplying only the aqueous sodium hydroxide solution to the hydrogen carrier, the reaction rate with the hydrogen carrier can be reduced, thereby accelerating or stopping hydrogen generation. Thus, a desired hydrogen generation rate can be obtained. The control of arbitrarily supplying any of the three liquids, namely water, aqueous citric acid solution, and aqueous sodium hydroxide solution, is any of the following: supplying only water, supplying water and aqueous citric acid solution, supplying only aqueous citric acid solution, supplying water + aqueous sodium hydroxide solution, and supplying only aqueous sodium hydroxide solution.

[0108] In addition, in the above configuration, a 100 mM phosphate buffer solution with a pH of 6.5 can also be used instead of water. In the case of using only water, the pH value of the water will change due to external environments such as carbon dioxide concentration, but by using the buffer solution, the pH can be stabilized, and thus a desired hydrogen generation rate can be obtained. Industrial Applicability

[0109] The hydrogen generation device according to the present invention can preferably be applied to a hydrogen generation device that generates hydrogen by using a hydrogen carrier having the property of generating hydrogen in response to an aqueous liquid poured thereon as a raw material. List of Reference Numerals

[0110] 1, 1A, 1B: Hydrogen generation device 12: Powder coating device (coating device) 22: Liquid discharge device (first liquid supply device) 23: Linear inkjet head 24: Serial inkjet head 25: Temperature adjustment device 26: Liquid supply device (second liquid supply device) 31: Hydrogen collection device 41: Conveyor belt (transport component) 41a: Surface 61: By-product collection device (solid product collection device) 112: Controller 220, 220A: Head 221: Flow path 222: Heater 222A: Piezoelectric element 223: Bubble 224: Liquid 225, 225A: Nozzle

Claims

1. A hydrogen generation device, comprising: A first liquid supply device configured to supply a liquid containing at least water to a solid hydrogen carrier; and A controller configured to control the amount of the liquid supplied by the first liquid supply device to the hydrogen carrier.

2. The hydrogen generation device according to claim 1, comprising a hydrogen collection device configured to collect hydrogen generated by the reaction between the hydrogen carrier and the liquid.

3. The hydrogen generation device according to claim 1, comprising a transfer member capable of transferring the hydrogen carrier.

4. The hydrogen generation device according to claim 3, comprising a coating device configured to coat the hydrogen carrier on the transfer member.

5. The hydrogen generation device according to claim 3, comprising a solid product collection device configured to collect solid products generated by the reaction between the hydrogen carrier on the transfer member and the liquid.

6. The hydrogen generation device according to claim 1, wherein, The hydrogen carrier is a metal hydride.

7. The hydrogen generation device according to claim 1, wherein, The hydrogen carrier is sodium borohydride.

8. The hydrogen generation device according to claim 1, wherein, The first liquid supply device includes a nozzle configured to discharge the liquid in the form of droplets.

9. The hydrogen generation device according to claim 1, wherein, The first liquid supply device is an inkjet head.

10. The hydrogen generation device according to claim 1, wherein, The first liquid supply device discharges the liquid by generating bubbles by setting a heater in a flow path filled with the liquid and heating by the heater.

11. The hydrogen generation device according to claim 1, wherein, The first liquid supply device discharges the liquid by setting a piezoelectric element in a flow path filled with the liquid and applying a voltage to the piezoelectric element.

12. The hydrogen generation device according to claim 1, wherein, The first liquid supply device discharges the liquid in the form of droplets of 100 pl or less.

13. The hydrogen generation device according to claim 1, wherein, The first liquid supply device discharges the liquid in the form of droplets of 20 pl or less.

14. The hydrogen generation device according to claim 1, further comprising a temperature adjustment device configured to adjust the temperature of the liquid in the first liquid supply device to be higher than 0°C and equal to or lower than 80°C.

15. The hydrogen generation device according to claim 1, wherein, The first liquid supply device is capable of adding two or more liquids with different pH values.

16. The hydrogen generation device according to claim 15, wherein, One of the two or more liquids contains an acidic substance.

17. The hydrogen generation device according to claim 15, wherein, One of the two or more liquids contains a basic substance.

18. The hydrogen generation device according to claim 4, further comprising a second liquid supply device capable of supplying an aqueous liquid to the transfer member before coating the hydrogen carrier on the transfer member by the coating device.

19. The hydrogen generation device according to claim 18, wherein, The controller is configured to control the amount of the liquid supplied by the second liquid supply device to the hydrogen carrier.

20. A hydrogen generation device, comprising: A liquid supply device configured to supply an aqueous liquid to a solid hydrogen carrier; and A hydrogen collection device configured to collect hydrogen generated by the reaction between the hydrogen carrier and the liquid, Among them, The liquid supply device supplies the liquid to the hydrogen carrier in the form of droplets.

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