JP2007326742A - Manufacturing method of hydrogen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of hydrogen capable of manufacturing hydrogen simply and efficiently. <P>SOLUTION: In this method, hydrogen is manufactured by reacting a hydrogen generating substance containing a metal selected from the group consisting of aluminum, silicon, zinc, magnesium, and an alloy mainly composed of at least one of those metals, and containing not less than 80 mass% particles having a particle diameter not greater than 100 μm, with water having a dissolved sulfate ion concentration of at most 700 ppm and an ion conductivity at 25°C of 10-2,200 μS/cm. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a hydrogen production method for producing hydrogen by reacting a hydrogen generating substance with water.

  In recent years, with the widespread use of cordless devices such as personal computers and mobile phones, batteries that are power sources are increasingly required to be smaller and have higher capacities. Currently, lithium ion secondary batteries have been put into practical use as batteries that have high energy density and can be reduced in size and weight, and demand for portable power sources is increasing. However, this lithium ion secondary battery has a problem that it cannot guarantee a sufficient continuous use time for some cordless devices.

  In order to solve the above problems, for example, development of fuel cells such as polymer electrolyte fuel cells (PEFC) is underway. The fuel cell can be used continuously if fuel and oxygen are supplied. A PEFC that uses a solid polymer electrolyte as an electrolyte, oxygen in the air as a positive electrode active material, and fuel as a negative electrode active material has attracted attention as a battery having a higher energy density than a lithium ion secondary battery.

  Regarding fuels used in PEFC, hydrogen, methanol, and the like have been proposed and various developments have been made. However, PEFCs using hydrogen as a fuel are expected from the viewpoint of high energy density.

  As hydrogen supplied to a fuel cell such as PEFC, for example, hydrogen obtained by a method of reacting a hydrogen generating material serving as a hydrogen source with water, such as aluminum, magnesium, silicon, and zinc, can be considered (Patent Document 1). ~ 4).

US Pat. No. 6,506,360 Japanese Patent No. 2566248 JP 2004-231466 A JP 2004-123517 A

  However, according to the method described in Patent Documents 1 to 3 in which aluminum is reacted with an alkali or acid, hydrogen is easily generated chemically, but it is necessary to add an equivalent amount of alkali or acid suitable for aluminum. The problem of a decrease in energy density occurs due to an increase in the ratio of materials other than the hydrogen source. Moreover, the risk to the human body in the event of a leak is very high.

  Furthermore, in the method of Patent Document 4 in which a metal material is rubbed in water and reacted with water while mechanically destroying the metal material, the amount of hydrogen generated is small relative to the total amount of metal material to be supplied and water. There is a problem that hydrogen generation efficiency is low.

  This invention is made | formed in view of the said situation, The objective is to provide the hydrogen production method which can manufacture hydrogen simply and efficiently.

  The hydrogen production method of the present invention that has achieved the above object contains at least one metal selected from the group consisting of aluminum, silicon, zinc, magnesium, and an alloy mainly composed of at least one of these metal elements. In addition, a hydrogen generating material containing 80% by mass or more of particles having a particle size of 100 μm or less and a dissolved sulfate ion concentration of 700 ppm (mass basis. The same applies to various ion concentrations in water described in this specification). This is a method characterized in that hydrogen is generated by reacting with water having an ionic conductivity at 25 ° C. of 10 to 2200 μS / cm.

  For example, the reaction between aluminum and water is considered to proceed according to any of the following formulas (1) to (3). The calorific value according to the following formula (1) is 419 kJ / mol.

2Al + 6H ₂ O → Al ₂ O ₃ .3H ₂ O + 3H ₂ (1)
2Al + 4H ₂ O → Al ₂ O ₃ .H ₂ O + 3H ₂ (2)
2Al + 3H ₂ O → Al ₂ O ₃ + 3H ₂ (3)

  The hydrogen generating material used in the method of the present invention is mainly composed of metals such as aluminum, silicon, zinc and magnesium and alloys mainly composed of these metal elements, and is used as particles having various shapes. Such particles are generally composed of a particle interior containing the metal or alloy in a metal state and a surface film (oxide film) covering at least a part of the particle interior. In the reaction between such a hydrogen generating substance and water, when water penetrates the surface film and reaches the metal or alloy inside the particles, the above formulas (1) to (3) Such a reaction occurs and hydrogen is generated. However, since an oxide film is formed on the surface and the hydrogen generating substance is stabilized, the hydrogen generating reaction is stopped.

However, as a result of repeated extensive studies by the present inventors, when hydrogen is produced using a hydrogen generating substance that can form a surface film as described above and water, it depends on the dissolved sulfate ion concentration and ionic conductivity of the water. It was revealed that there was a big difference in hydrogen generation behavior. Then, hydrogen having a dissolved sulfate ion (SO ₄ ²⁻ ) concentration of 700 ppm or less and an ionic conductivity at 25 ° C. of 10 to 2200 μS / cm is generated as hydrogen having the specific form (the specific particle size distribution). It has been found that if the substance is supplied to the substance, the hydrogen generation reaction can proceed well and the amount of hydrogen generation can be increased to enable efficient hydrogen production, and the present invention has been completed.

  According to the method of the present invention, hydrogen can be produced easily and efficiently. That is, according to the method of the present invention, a hydrogen generating material having a specific form is reacted with water having a specific dissolved sulfate ion concentration and a specific ion conductivity, and can be promptly obtained without the need for special operation / equipment. Hydrogen can be produced and is simple, and the amount of hydrogen obtained relative to the amount of the hydrogen generating substance and water used is large, and the hydrogen generation efficiency is high. Therefore, it is also possible to produce hydrogen by a portable device. For example, by using hydrogen obtained by the method of the present invention as a hydrogen source of the fuel cell, it is possible to achieve miniaturization and high energy density of the fuel cell. .

  The hydrogen generating substance according to the method of the present invention contains a metal such as aluminum, silicon, zinc or magnesium, or an alloy mainly composed of one or more metal elements selected from aluminum, silicon, zinc and magnesium. In the case of the above alloy, elements other than the above metal elements as the main elements are not particularly limited. Here, the “main body” means that 80% by mass or more, more preferably 90% by mass or more is contained with respect to the entire alloy. Only one of the above exemplified metals and alloys may be used as the hydrogen generating material, or two or more may be used in combination. These hydrogen generating substances are substances that do not easily react with water at room temperature, but are easily exothermic with water when heated. In this specification, normal temperature is a temperature in the range of 20 to 30 ° C.

  The hydrogen generating material preferably contains 60% by mass or more of the above metal or alloy in the total amount of the hydrogen generating material. Although the hydrogen generating material is usually used in the form of particles, as described above, the above-mentioned metal or alloy constituting the hydrogen generating material often forms a surface film as an oxide or the like on its surface portion. Such oxides do not contribute to the hydrogen generation reaction. A component that can contribute to the hydrogen generation reaction in the hydrogen generation material if the metal or alloy contained in the hydrogen generation material is contained in a metal state rather than an oxide or the like in the total amount of the hydrogen generation material in an amount of 60% by mass or more. Since the amount increases, the hydrogen generation efficiency can be further increased. The content of the metal or alloy in the total amount of the hydrogen generating material is more preferably 80% by mass or more, and most preferably 100% by mass, but it is difficult to achieve 100% by mass. Usually, the upper limit is about 98% by mass.

  In order to adjust the content of the metal or alloy in the hydrogen generating material as described above, an alloy mainly composed of aluminum, silicon, zinc, magnesium and one or more metal elements used as a hydrogen generating source. The pulverization conditions may be adjusted as appropriate. In particular, when pulverizing by a ball mill method or a vibration mill method which is a wet pulverization method, the water content of at least the solvent used is 1 part by mass or less, more preferably 1 part by mass of the metal or alloy to be pulverized. The amount is desirably 0.4 parts by mass or less. If the amount of water in the solvent used during pulverization is too large, oxidation of the metal or alloy proceeds during pulverization, and the content of the metal or alloy in the hydrogen generating material decreases, resulting in a decrease in hydrogen generation. May cause.

  The content of the metal or alloy in the total amount of the hydrogen generating substance referred to in the present specification (content in the metal state) is measured as follows. When the hydrogen generating substance is analyzed by an X-ray diffractometer (XRD), the metal and the oxide or hydroxide of the metal are observed. Therefore, the content of metal and oxygen in the hydrogen generating material is measured by fluorescent X-ray analysis (XRF), the content of metal oxide or hydroxide is determined from the oxygen content, and the remaining metal content is calculated. The content of the metal state.

  The hydrogen generating material used in the method of the present invention contains 80% by mass of particles having a particle size of 100 μm or less in the total hydrogen generating material. As described above, a hydrogen generating material composed of the above metal or alloy generally has a stable surface film (oxide film) formed on the surface. Therefore, in the case of forms such as a plate shape, a block shape, and a bulk shape having a particle size of 1 mm or more, the reaction with water does not proceed even when heated, and hydrogen may not be generated substantially. However, in the case where the hydrogen generating material has a particle size distribution as described above, the reaction with the water by the surface film is reduced, and although it is difficult to react with water at room temperature, it reacts with water when heated. The hydrogen generation reaction will continue to increase. The proportion of particles having a particle size of 100 μm or less contained in the hydrogen generating material is preferably 90% by mass or more, and most preferably 100% by mass.

  In order to adjust the proportion of particles having a particle size of 100 μm or less contained in the hydrogen generating material as described above, for example, aluminum, silicon, zinc, magnesium and one or more metals thereof used as a hydrogen generating source What is necessary is just to adjust suitably the grinding | pulverization conditions of the alloy which has an element as a main component. For example, in the mechanical grinding method using the ball mill method, sand mill method, vibration mill method, jet mill method, etc., the grinding time, the rotational speed of rotation, etc. What is necessary is just to adjust a pressure, a nozzle diameter, and molten metal temperature suitably.

  In order to increase the reactivity with water and generate hydrogen more efficiently, the average particle size of the hydrogen generating material is preferably 70 μm or less, particularly when the average particle size is 30 μm or less. Can further improve the reaction efficiency.

  Further, even when the average particle size of the hydrogen generating material exceeds 70 μm, if the hydrogen generating material is scaly and the thickness is 5 μm or less, the reactivity with water is increased, Hydrogen can be generated efficiently, and particularly when the thickness of the hydrogen generating material is 3 μm or less, the reaction efficiency can be further improved.

  On the other hand, if the average particle size of the hydrogen generating material is less than 0.1 μm, or if the thickness of the scaly hydrogen generating material is less than 0.1 μm, the ignitability becomes high and handling becomes difficult. The energy density is likely to decrease due to a decrease in the packing density. For this reason, the average particle size of the hydrogen generating substance is preferably 0.1 μm or more, and when the hydrogen generating substance is scaly, the thickness is preferably 0.1 μm or more.

  In addition, the average particle diameter of the hydrogen generating substance as used in this specification means the value of the particle diameter at a volume-based integrated fraction of 50%. As a method for measuring the average particle diameter, for example, a laser diffraction / scattering method or the like can be used. Specifically, this is a particle diameter distribution measurement method using a scattering intensity distribution detected by irradiating a measurement target substance dispersed in a liquid phase such as water with laser light. As a particle size distribution measuring apparatus using a laser diffraction / scattering method, for example, “Microtrack HRA” manufactured by Nikkiso Co., Ltd. can be used. The particle size distribution referred to in this specification is also measured by the above-described measuring method and measuring apparatus.

  Further, the thickness of the scaly hydrogen generating substance referred to in the present specification is confirmed by observing with a scanning electron microscope (SEM).

  The shape of the hydrogen generating substance is not particularly limited, and examples include a substantially spherical shape (including a true spherical shape) and a rugby ball shape, as well as a scaly shape as described above. In the case of a substantially spherical shape or a rugby ball shape, those satisfying the above average particle diameter are preferable, and in the case of a scale shape, those satisfying the above thickness are preferable. In the case of a scale-like hydrogen generating substance, it is more preferable that the above average particle diameter is also satisfied.

In the method of the present invention, the water to be reacted with the hydrogen generating substance has a dissolved sulfate ion concentration of 700 ppm and an ionic conductivity at 25 ° C. of 10 μS / cm to 2200 μS / cm. In addition, the ionic conductivity σ (μS / cm) of water referred to in the present specification is a value at 25 ° C. Specifically, the electrode area S (cm ² ) immersed in the water to be measured and the interelectrode L (Cm) is a value calculated from the following equation by measuring a resistance value R (Ω) when a frequency of 1 kHz is applied between two known electrodes.
σ = 10 ⁶ × L / (S × R)

  When water satisfying the above-described dissolved sulfate ion concentration and ionic conductivity is used for the hydrogen generation reaction, hydrogen can be efficiently generated even if the hydrogen generating material on which the above surface film is formed is used. The reason for this is not clear, but the dissolved sulfate ion concentration in water is such that the sulfate ion is a reaction product produced by the reaction between the hydrogen generating substance and water [for example, in the above formulas (1) to (3) It is thought that it has the effect | action which influences progress of the surface film | membrane (oxide film) by the reaction product to show], and hinders progress of hydrogen generation reaction, and uses the water whose dissolved sulfate ion concentration is 700 ppm or less Thus, it is presumed that the expression of such an action is suppressed. As for the ionic conductivity of water, depending on the ions dissolved in the water, it has the action of promoting the hydrogen generation reaction because it is corrosive to the hydrogen generation material, or the reaction between the hydrogen generation material and water. It is considered that the reaction product produced by the reaction has little effect on the formation of the surface film and has the effect of facilitating the hydrogen generation reaction. Water is added so that the ionic conductivity at 25 ° C. is 10 μS / cm or more. By containing various ions (excluding sulfate ions), it is presumed that the effect of the above-described action of these ions is obtained. In addition, when carrying out the method of the present invention using a portable fuel cartridge, which will be described later, if there is a large amount of dissolved sulfate ions in the water, a poorly water-soluble sulfate is formed along with the hydrogen generation reaction, which is the water supply. It may accumulate near the mouth and prevent water supply to the hydrogen generating material.

  When producing hydrogen by the method of the present invention, the reaction temperature may be close to the boiling point of water. At that time, a part of the supplied water may react with the hydrogen generating substance, and the remaining unreacted water may be discharged out of the reaction system together with hydrogen generated as water vapor. Thus, when a mixture of water vapor and hydrogen is supplied as fuel to the PEFC, for example, if ions are present in the water vapor, the proton exchange resin contained in the PEFC and the protons in the proton exchange membrane are replaced. Adsorption on the electrode, precipitation in the electrode, etc., resulting in a decrease in ion conductivity, a decrease in catalytic ability, a decrease in gas diffusion performance, etc., which may result in deterioration of the fuel cell . In addition, when dissolved ions are excessively present in water, the surface film formation of the hydrogen generating material accompanying the reaction between the hydrogen generating material and water tends to easily proceed. For these reasons, the water used in the method of the present invention has an ionic conductivity at 25 ° C. of 2200 μS / cm or less so as not to contain excessive amounts of various ions.

  The dissolved sulfate ion concentration of water is preferably 250 ppm or less, and more preferably the water does not substantially contain dissolved sulfate ions (substantially 0 ppm). As used herein, “water does not substantially contain dissolved sulfate ions (substantially 0 ppm)” means a state below the detection limit of sulfate ion concentration in the dissolved sulfate ion concentration measurement method described below. Yes.

  The ionic conductivity of water is preferably 50 μS / cm or more, and preferably 600 μS / cm or less.

The water used in the method of the present invention has the above-described ionic conductivity and contains various ions. Examples of ions dissolved in water include calcium ions (Ca ²⁺ ), magnesium ions (Mg ²⁺ ), sodium ions (Na ⁺ ), potassium ions (K ⁺ ), vanadium ions (V ⁵⁺ ), and germanium ions Ge. Cation such as ⁴⁺ ); carbonate ion (CO ₃ ²⁻ ), bicarbonate ion (HCO ₃ ⁻ ), chloride ion (Cl ⁻ ), nitrate ion (NO ₃ ⁻ ), citrate ion (C ₆ H ₅ O ₇₎ ^3- ), anions such as silicate ions (SiO ₂ ²⁻ ); Only one kind of these ions may be dissolved in water, or two or more kinds may be dissolved. In addition, sulfate ions as anions may be dissolved in the water, but the concentration must be 700 ppm or less.

  In addition, for example, it has the above-mentioned ion conductivity, the dissolved sodium ion concentration is 3 to 410 ppm, the dissolved chloride ion concentration is 5 to 610 ppm, and it does not substantially contain other dissolved ions (substantially When water is used for the hydrogen generation reaction, the reason is not clear, but hydrogen can be generated more efficiently.

  For example, it has the above-mentioned ionic conductivity, the dissolved magnesium ion concentration is 2 to 25 ppm, the dissolved sulfate ion concentration is 8 to 100 ppm, and does not substantially contain other dissolved ions (substantially If water is used for the hydrogen generation reaction, the reason is not clear, but hydrogen can be generated more efficiently.

  Further, for example, it has the above-described ion conductivity, the dissolved sodium ion concentration is 2 to 460 ppm, the dissolved citrate ion concentration is 5 to 1260 ppm, and it does not substantially contain other dissolved ions (substantially When water is used for the hydrogen generation reaction, the reason is not clear, but hydrogen can be generated more efficiently.

  Here, the above-mentioned “substantially does not contain other dissolved ions (substantially 0 ppm)” means a state that is below the detection limit when measuring the concentration of various dissolved ions. Yes.

  In addition, the dissolved sulfate ion concentration, the dissolved chloride ion concentration, and the dissolved citrate ion concentration referred to in the present specification are values measured using an ion chromatograph (“ICS-1500” manufactured by Nippon Dionex Co., Ltd.). Moreover, the dissolved sodium ion concentration and the dissolved magnesium ion concentration as used in the present specification are values measured using ICP emission analysis (“IRIS1000” manufactured by Thermo Electron Co., Ltd.).

The water used in the method of the present invention preferably has a hardness of 1 mg / L or more, more preferably 10 mg / L or more, 1500 mg / L or less, more preferably 500 mg / L or less. Here, the hardness of water refers to the amount of calcium ions A (mg / L) and the amount of magnesium ions B (mg / L) dissolved in water converted to the corresponding amount of calcium carbonate (CaCO ₃ ). The number of mg per 1 L (liter) of water, that is, expressed in mg / L, is expressed by the following formula.
Hardness = A × 2.5 + B × 4.1

  If the hardness of the water used for the production of hydrogen is the above value, the ionic conductivity of water can be used as the above specific value to enable efficient production of hydrogen. The hardness of water may be adjusted by controlling the concentration of the various ions exemplified above that can be dissolved in water.

  Incidentally, water having an ionic conductivity at 25 ° C. of 10 μS / cm or more and 2200 μS / cm or less and a dissolved sulfate ion concentration of 700 ppm or less is also available in, for example, commercially available mineral water. It is easy and convenient.

  Next, specific embodiments of the hydrogen production method of the present invention will be described with reference to the drawings of a hydrogen production apparatus that can be used when hydrogen is produced by the hydrogen production method of the present invention. FIG. 1 is a partial cross-sectional view schematically showing a configuration example of a hydrogen production apparatus to which the hydrogen production method of the present invention can be applied. The hydrogen production apparatus of FIG. 1 includes a lid 1a and a container main body 1b, contains a hydrogen generating substance 2, and a hydrogen generating substance container 1 for reacting the hydrogen generating substance 2 with water. A water storage container 3 for storing water 4 supplied to the hydrogen generation substance storage container and a water supply pipe 5 for supplying water from the water storage container 3 to the hydrogen generation substance storage container 1 are provided. In the apparatus of FIG. 1, the water supply pipe 5 is provided with a pump 10 (such as a micropump), and this pump 10 accommodates the hydrogen generating substance from the water supply port 6 (the pipe port portion of the water supply pipe 5). The water 4 can be continuously supplied into the container 1. The water 4 supplied into the hydrogen generating substance storage container 1 reacts with the hydrogen generating substance 2 to generate hydrogen. The hydrogen produced by this reaction is taken out of the hydrogen production apparatus through the hydrogen lead-out port 8 provided in the hydrogen generating substance storage container 1 through the hydrogen lead-out pipe 8. Further, 9 in the apparatus of FIG. 1 is a heat insulating material disposed outside the hydrogen generating substance storage container 1.

  The material of the hydrogen generating substance storage container 1 and the material of the water storage container 3 are not particularly limited as long as they are materials that do not easily transmit water and hydrogen and that do not break even when heated to about 100 ° C. Metals such as titanium and nickel, resins such as polyethylene, polypropylene, and polycarbonate, ceramics such as alumina, silica, and titania, and materials such as glass (particularly heat-resistant glass) can be used. Further, the water supply pipe 5 and the hydrogen lead-out pipe 8 can also be made of the same material as the hydrogen generating substance storage container 1 and the like. In order to prevent contents other than hydrogen from leaking out of the apparatus, a filter such as a gas-liquid separation membrane may be installed in the hydrogen outlet 7 as necessary.

  In addition, as shown in FIG. 1, it is preferable that the heat insulating material 9 is arrange | positioned at the outer periphery of the hydrogen generating substance storage container 1. FIG. This makes it easier to maintain a temperature at which the exothermic reaction between the hydrogen generating substance and water can be maintained, and also makes it less susceptible to outside air temperatures. The material of the heat insulating material 9 is not particularly limited as long as it has high heat resistance, and examples thereof include porous heat insulating materials such as foamed polystyrene and polyurethane foam, or heat insulating materials having a vacuum heat insulating structure.

  In order to easily start the reaction between water and the hydrogen generating substance, it is preferable to heat at least one of the hydrogen generating substance and water. The heating temperature is 40 ° C. or higher, more preferably 60 ° C. or higher, and desirably 100 ° C. or lower. The temperature at which the exothermic reaction between the hydrogen generating substance and water can be maintained is usually 40 ° C. or higher. Once the exothermic reaction starts and hydrogen is generated, the internal pressure of the hydrogen generating substance storage container increases and the water is increased. Although the boiling point may rise and the temperature in the container may reach 120 ° C., it is preferably 100 ° C. or less from the viewpoint of controlling the hydrogen generation rate.

  The heating may be performed only at the start of the exothermic reaction. This is because once the exothermic reaction between water and the hydrogen generating substance is started, the subsequent reaction can be continued by the heat of the exothermic reaction. In addition, you may perform said heating and the supply of the water to the inside of the hydrogen generating substance storage container 1 simultaneously.

  Although the heating method is not particularly limited, heating can be performed using heat generated by energizing the resistor. Although not shown in FIG. 1, for example, this resistor is attached to the outside of the hydrogen generating substance storage container 1 to generate heat, and at least one of the hydrogen generating substance and water is heated by heating these containers from the outside. can do. Further, a resistor may be attached to the outside of the water container 3 so that the water container is heated from the outside. The type of the resistor is not particularly limited, and for example, a metal heating element such as a nichrome wire or a platinum wire, silicon carbide, a PTC thermistor, or the like can be used.

  The heating can also be performed by heat generated by a chemical reaction of the heat generating material. As the exothermic material, a substance that becomes an hydroxide or a hydrate by exothermic reaction with water, a substance that produces exothermic reaction with water and hydrogen can be used. Examples of the substance that forms an hydroxide or hydrate by exothermic reaction with water include alkali metal oxides (such as lithium oxide) and alkaline earth metal oxides (such as calcium oxide and magnesium oxide). Alkaline earth metal chlorides (such as calcium chloride and magnesium chloride), alkaline earth metal sulfate compounds (such as calcium sulfate), and the like can be used. Examples of the substances that generate hydrogen by exothermic reaction with water include alkali metals (lithium, sodium, etc.), alkali metal hydrides (sodium borohydride, potassium borohydride, lithium hydride, etc.), etc. Can be used. These substances can be used alone or in combination of two or more.

  When hydrogen is produced using the hydrogen production apparatus shown in FIG. 1, the heat generating material is placed in the hydrogen generating material containing container 1 together with the hydrogen generating material, and water is added to these to generate water and the heat generating material. And the hydrogen generating substance and water can be directly heated inside the hydrogen generating substance storage container 1. In addition, the heat generating material is disposed outside the hydrogen generating material storage container 1 or the water storage container 3 to generate heat, and these containers are heated from the outside, thereby at least one of the hydrogen generating material and water. Can be heated.

  In addition, as exothermic material, the substance which exothermically reacts with substances other than water, for example, the substance which exothermically reacts with oxygen like iron powder, is also known. Since such a substance needs to introduce oxygen for an exothermic reaction, it is not placed in the hydrogen generating substance container 1 but placed outside the hydrogen generating substance container 1 or the water container 3. It is preferable to use it.

  When the above heat generating material is stored in a hydrogen generating material storage container together with a hydrogen generating material and heated by supplying water to this, the heat generating material is used as a mixture in which the hydrogen generating material is uniformly or non-uniformly dispersed and mixed. However, it is more preferable that the heat generating material is unevenly arranged in the hydrogen generating substance storage container, and the port portion (FIG. 1) of the water supply pipe (5 in FIG. 1) inside the hydrogen generating substance storage container. In particular, it is particularly preferable that the heat generating material is unevenly distributed in the vicinity of 6). By unevenly distributing the heat generating material inside the hydrogen generating substance storage container, it is possible to shorten the time from the start of supplying water until the hydrogen generating substance is heated, and to produce hydrogen more quickly. can do.

  In order to make the heat generating material unevenly distributed in the vicinity of the mouth portion of the water supply pipe inside the hydrogen generating substance storage container, in addition to arranging only the heat generating material in the vicinity of the above mouth portion, two or more types of hydrogen generation with previously changed mixing ratios It is also possible to prepare a mixture of a substance and a heat generating material, arrange a mixture with a high ratio of the heat generating material near the tube opening, and arrange a mixture with a low ratio of the heat generating material in the other part (this Of these, the latter will be described in detail in Examples below).

  In addition, since the reaction between the metal constituting the hydrogen generating material and water (hydrogen generating reaction) is also an exothermic reaction, if the heat generated from the reaction heat is prevented and used to increase the temperature of the hydrogen generating material or water, the above heat source is generated. It is possible to continuously generate hydrogen without having any. That is, only heating is performed at the initial stage of the reaction, and even if heating is stopped after hydrogen generation has started, the heated state can be maintained by the exothermic heat of the hydrogen generation reaction. In the case of performing such heating, as shown in the apparatus of FIG. 1, a heat insulating material 9 is disposed on the outer periphery of the hydrogen generating substance storage container 1 so that the heat in the hydrogen generating substance storage container 1 is transferred to the outside. It is preferable to suppress release.

  In the method of the present invention, the amount of hydrogen generation can be controlled by controlling the supply of water to be reacted with the hydrogen generating substance.

  When the hydrogen produced by the hydrogen production method of the present invention is applied to a small fuel cell or a portable electronic device, for example, a hydrogen production apparatus as shown in FIG. 2, that is, a portable fuel cartridge is used. Can do. FIG. 2 is a cross-sectional view showing a configuration example of the fuel cartridge. However, in order to facilitate understanding of each component, hatched lines indicating the cross-section are not attached. In FIG. 2, elements having the same functions as those in FIG. 1 are denoted by the same reference numerals (the same applies to FIGS. 3 and 5 described later).

  The fuel cartridge of FIG. 2 has a hydrogen generating substance storage container 1 in which a hydrogen generating substance 2 is sealed, and water for supplying water to the hydrogen generating substance 2 as in the hydrogen production apparatus shown in FIG. A supply pipe 5 and a hydrogen outlet pipe 8 for taking out the hydrogen produced in the container 1 to the outside of the cartridge are provided. After the fuel cartridge is mounted on the fuel cell or portable electronic device, water is supplied into the container 1 through the water supply port 6 of the water supply pipe 5 using a pump (such as a micropump, not shown), or Alternatively, a water storage container (not shown) filled with water is previously provided in a part of the fuel cartridge, and after the fuel cartridge is mounted on the fuel cell or portable electronic device, the water in the water storage container is stored in the container 1. It suffices to have a structure that can be supplied inside.

  In the fuel cartridge of FIG. 2, a part of the water supplied to the inside is held by the water-absorbing materials 11, 11, and the remaining part wets the hydrogen generating material, and the hydrogen generating reaction is started. The generated hydrogen is supplied from the hydrogen outlet 7 through the hydrogen outlet pipe 8 to the negative electrode of the fuel cell. Although the water absorbing materials 11 and 11 are not necessarily required, the water held by the water absorbing materials 11 and 11 is also supplied to the hydrogen generating material according to the consumption of water by the hydrogen generating reaction. It becomes possible to suppress to some extent. The water-absorbing material is not particularly limited as long as it is made of a material that can absorb and hold water, and generally absorbent cotton or nonwoven fabric can be used.

  When producing hydrogen by the hydrogen production method of the present invention, as described above, the hydrogen generation reaction temperature becomes a temperature close to the boiling point of water, and a part of the supplied water then reacts with the hydrogen generation substance, The remaining unreacted water may be discharged to the outside of the reaction system (outside of the hydrogen generating substance storage container 1) together with hydrogen generated as water vapor. When such a mixture of water vapor and hydrogen is supplied to PEFC, There is a possibility of causing the deterioration. If there is a concern about the occurrence of such a problem, a hydrogen equipped with a gas-liquid separation unit for separating the mixture of water (water vapor) and hydrogen discharged from the hydrogen generating substance storage container into water and hydrogen. It is preferable to carry out the method of the present invention using a production apparatus.

  In FIG. 3, the fragmentary sectional view showing the structural example of the hydrogen production apparatus which has a gas-liquid separation part is shown. The apparatus shown in FIG. 3 has a water storage container 3 and a gas-liquid separation unit 12, and water 4 used for reaction with the hydrogen generation material is supplied from the water storage container 3 through the water supply pipe 5. It is supplied to the container 1. The mixture of water and hydrogen discharged from the hydrogen generating substance storage container 1 is configured to be introduced into the gas-liquid separator 12 through the hydrogen outlet pipe 8.

  In the gas-liquid separation unit 12, of the mixture of hydrogen and water flowing in from the hydrogen outlet pipe 8, water falls below the gas-liquid separation unit 12 by gravity and is separated from hydrogen. The separated hydrogen is taken out of the apparatus from the hydrogen outlet pipe 12a.

  Moreover, in the apparatus of FIG. 3, the water separated by the gas-liquid separator 12 can be returned to the water container 3 through the water recovery pipe 12b. Therefore, since the amount of water used can be substantially reduced, the amount of water stored in the water storage container 3 can be reduced, and the volume and weight of the hydrogen production apparatus can be reduced to make it compact. it can.

  The structure of the gas-liquid separator 12 is not limited to that shown in FIG. 3. For example, a conventionally known microporous membrane made of polytetrafluoroethylene, or polyvinylidene fluoride subjected to water repellent treatment, polyethylene, The gas-liquid separation part can also be configured using a gas-liquid separation membrane such as a microporous membrane of polypropylene or polyethersulfone.

  In order to improve the water recovery efficiency in the gas-liquid separation unit 12, it is also preferable to provide a cooling unit (not shown) between the hydrogen generating substance storage container 1 and the gas-liquid separation unit 12. If the mixture of water and hydrogen discharged from the hydrogen generating substance storage container 1 is cooled by the cooling unit before entering the gas-liquid separation unit 12, the water vapor contained therein can be changed to liquid water. The water recovery efficiency in the liquid separation unit 12 can be increased. As the cooling unit, for example, a cooling unit having a structure in which metal cooling fins are arranged in contact with the pipe can be used. Furthermore, an air cooling fan can also be used.

  Furthermore, it is preferable to provide a pressure relief valve in the hydrogen production apparatus. For example, even when the hydrogen generation rate increases and the internal pressure of the apparatus rises, the apparatus can be prevented from being damaged due to rupture or the like by discharging hydrogen from the pressure relief valve to the outside of the apparatus. The installation location of the pressure relief valve may be a location where hydrogen generated in the hydrogen generating substance storage container can be discharged. For example, in the apparatus shown in FIG. 3, a pressure relief valve may be provided at any location between the hydrogen outlet pipe 8 and the gas-liquid separator 12.

  The hydrogen production apparatus shown in FIGS. 1 and 3 and the fuel cartridge shown in FIG. 2 are examples of apparatuses that can be used for carrying out the hydrogen production method of the present invention. However, it is not limited to these.

Further, for example, as a method for producing hydrogen, a method by reforming a hydrocarbon-based fuel is also known, but hydrogen obtained by such a method contains gases such as CO and CO ₂ , and such hydrogen If the gas is supplied to a PEFC operating at 100 ° C. or lower, the problem of poisoning by these gases arises. On the other hand, since the hydrogen produced by the method of the present invention does not contain the above gas, such a problem does not occur, and since water is involved in the reaction, the gas contains appropriate moisture. Can be preferably used in a fuel cell using as a fuel.

  Hereinafter, the present invention will be described in detail based on examples. However, the following examples are not intended to limit the present invention, and all modifications made without departing from the spirit of the preceding and following descriptions are included in the technical scope of the present invention.

(Examples 1-3)
1 g of a hydrogen generating material consisting only of a hydrogen generating material, which is an aluminum powder shown in Table 1, produced by an atomizing method, and water having various dissolved ion concentrations, ionic conductivity, and hardness shown in Table 2 [manufactured by Calpis Itochu Mineral Water Co. “Evian (registered trademark)” 10 g was placed in a glass sample bottle with an internal volume of 50 cm ³ each, and a resistor was placed outside the sample bottle. The container was heated by energizing the resistor, and the hydrogen generating material was heated to 50 ° C. to react with water to generate hydrogen. The produced hydrogen was collected by a water displacement method, and the amount of hydrogen generated 24 hours after the start of the reaction was determined.

  In addition, when heating was stopped and the hydrogen generating material and water were allowed to cool, it was confirmed that hydrogen generation stopped after a few minutes.

  FIG. 4 is a graph showing the particle size distribution of the hydrogen generating material used in Example 1. In the graph of FIG. 4, the horizontal axis represents the particle size (μm) of the hydrogen generating substance, and the vertical axis represents the frequency (volume%). As is clear from this graph, the hydrogen generation used in Example 1 is shown. The substances are all particles having a particle size of 100 μm or less (that is, 100% by mass of particles having a particle size of 100 μm or less).

Example 4
Except for changing the water used for the hydrogen generation reaction to water having various dissolved ion concentrations, ion conductivity and hardness shown in Table 2 [“Mori no Miyori (registered trademark)” manufactured by Coca-Cola Co., Ltd.] Hydrogen production was carried out in the same manner as in Example 3.

(Example 5)
Hydrogen production was carried out in the same manner as in Example 3 except that the water used for the hydrogen generation reaction was changed to water having various dissolved ion concentrations, ion conductivity and hardness shown in Table 2 (aqueous sodium chloride solution). .

(Example 6)
Hydrogen was produced in the same manner as in Example 3 except that the water used for the hydrogen generation reaction was changed to water having various dissolved ion concentrations, ionic conductivity, and hardness (magnesium sulfate aqueous solution) shown in Table 2. .

(Example 7)
Hydrogen production was carried out in the same manner as in Example 3 except that the water used for the hydrogen generation reaction was changed to water having various dissolved ion concentrations, ionic conductivity and hardness shown in Table 2 (trisodium citrate aqueous solution). went.

(Example 8)
5 g of aluminum powder having an average particle size of 55 μm prepared by the atomization method, 15 g of toluene, 1 g of water and 85 g of beads made of zirconia (particle size 2 mm) are put in a grinding pot of a planetary ball mill, and the aluminum powder is rotated at a rotation speed of 200 rpm. Was crushed. Since hydrogen was generated during the pulverization, after rotating for 10 minutes, the rotation was temporarily stopped to release the generated hydrogen in the pot, and then the pot was rotated again. This procedure was repeated to rotate the pot for a total of 1 hour. Thereafter, toluene and water were removed by drying under reduced pressure to obtain a hydrogen generating material of this example shown in Table 1.

  Hydrogen production was performed in the same manner as in Example 1 except that the hydrogen generating material composed of the pulverized aluminum powder was directly used as a hydrogen generating material, and 1 g of this hydrogen generating material was used.

Example 9
6 g of aluminum powder with an average particle diameter of 55 μm and 18 g of methanol prepared by the atomizing method are put into a planetary ball mill grinding pot together with zirconia beads, and the aluminum powder is pulverized by rotating the pot at a rotation speed of 200 rpm. did. Thereafter, the solvent was removed by drying under reduced pressure to obtain the hydrogen generating materials shown in Table 2. The average particle size of the pulverized aluminum powder (hydrogen generating material) was measured by a laser diffraction / scattering method using “Microtrack HRA” manufactured by Nikkiso Co., Ltd. As a result, the thickness was found to be several tens of micrometers. In addition, observation with a scanning electron microscope confirmed that the particles had changed to scale-like particles having a metallic luster having a major axis of about 10 to 200 μm and a thickness of about 0.5 to 5 μm. Therefore, the average particle diameter measured by the laser diffraction / scattering method is considered to represent the average of the long diameter of the aluminum powder. In addition, the moisture content of the used methanol was less than 1 mass%.

  Hydrogen production was performed in the same manner as in Example 1 except that the hydrogen generating material composed of the pulverized aluminum powder was directly used as a hydrogen generating material, and 1 g of this hydrogen generating material was used.

(Comparative Example 1)
Hydrogen production was carried out in the same manner as in Example 1 except that the hydrogen generating material was changed to the aluminum powder shown in Table 1 produced by the atomizing method.

(Comparative Example 2)
Hydrogen was produced in the same manner as in Example 1 except that the water used for the hydrogen generation reaction was changed to water having various dissolved ion concentrations, ionic conductivity, and hardness (potassium chloride aqueous solution) shown in Table 2. .

(Comparative Example 3)
Example 1 except that the water used in the hydrogen generation reaction was changed to water having various dissolved ion concentrations, ion conductivity and hardness shown in Table 2 [“Contrex (registered trademark)” manufactured by Nestle Group, Inc.] Hydrogen production was carried out in the same manner.

  Table 3 shows the amount of hydrogen generated 24 hours after the start of the reaction determined in the hydrogen generation tests of Examples 1 to 9 and Comparative Examples 1 to 3.

  As shown in Table 3, in Examples 1 to 9 in which hydrogen was generated by the hydrogen production method of the present invention, hydrogen was efficiently generated. On the other hand, in Comparative Example 1, the amount of hydrogen generated was smaller than in Examples 1 to 3 in which hydrogen was produced using the same water. This is presumably because the amount of hydrogen generation decreased because the ratio of particles of 100 μm or less in the hydrogen generating material used in Comparative Example 1 was small. Further, the hydrogen generation amount in Example 2 was improved compared to Example 1 and in Example 3 as compared with Example 2, which is considered to be caused by the decrease in the average particle size. It is done. Furthermore, the hydrogen generation amount in Example 8 is higher than that in Example 1 in spite of the low content of aluminum present in the metal state in the hydrogen generation material. This is thought to be due to the decrease in the average particle size of Moreover, in Examples 4-7, there was more hydrogen generation amount than Example 3 which reacted using the same hydrogen generating substance.

  Furthermore, in Comparative Examples 2 and 3, the amount of hydrogen generation was smaller than that in Example 1 in which the reaction was performed using the same hydrogen generating material. This is considered to be because the ionic conductivity of the used water is large in Comparative Example 2 and the dissolved sulfate ion concentration of the used water is large in Comparative Example 3.

  Moreover, in Example 9, the result with the largest amount of hydrogen generation was obtained in all Examples by using the hydrogen generating substance which has a scale-like shape with a thickness of 2 μm.

(Example 10)
Using the apparatus shown in FIG. 5 (fuel cartridge. FIG. 5 is a cross-sectional view, but in order to facilitate understanding of each component, the hatching indicating the cross-section is not attached). Hydrogen was generated by the procedure. The hydrogen generating material A was produced by mixing 1.0 g of the aluminum powder used in Example 1 and 1.0 g of calcium oxide powder (Aldrich, average particle size: 40 μm) in a mortar. Further, 19.7 g of the aluminum powder and 2.5 g of the calcium oxide powder were mixed in a mortar to prepare a hydrogen generating material B.

Next, 0.1 g of absorbent cotton as a water absorbing material 9 is put in a polyethylene container (hydrogen generating substance storage container 1; 34 mm in length, 34 mm in width, 82 mm in height, 160 cm ³ in internal volume), and then the hydrogen generating material A (2a in FIG. 5) 2g and 22.2g of the hydrogen generating material B (2b in FIG. 5) were filled with an inclination as shown in FIG. Between the hydrogen generating material A and the hydrogen generating material B, an aluminum foil 2c was disposed as a partitioning material. Furthermore, 0.1 g of absorbent cotton was added as the water absorbing material 11 on the hydrogen generating material B.

  Next, an aluminum water supply pipe 5 for supplying water is introduced so that the pipe opening portion (water supply port 6) is in the vicinity of the hydrogen generating material A, and the hydrogen made of aluminum for deriving hydrogen. The aluminum plate provided with the outlet tube 8 was capped, and the polyethylene container 1 filled with the hydrogen generating materials A and B was obtained. Then, a polystyrene foam heat insulating material having a thickness of 5 mm was installed so as to include the outer periphery of the polyethylene container 1.

  Next, a pump for supplying water to the hydrogen generating materials A and B was installed at the tip of the water supply pipe 5 (tip opposite to the polyethylene container 1 side). That is, by supplying water from a water container (not shown) using the pump, first, water and the heat generating material (calcium oxide powder) contained in the hydrogen generating material A undergo an exothermic reaction, Water and the hydrogen generating material (aluminum powder) contained in the hydrogen generating materials A and B start a hydrogen generating reaction.

  By supplying the same water as used in Example 1 from the pump at a rate of 0.8 ml / min and supplying water into the polyethylene container 1, a hydrogen generating material (aluminum powder) contained in the hydrogen generating material is supplied. ) And water to generate hydrogen. At 25 ° C., water was supplied until no more hydrogen was generated, and hydrogen was collected from the hydrogen outlet pipe 6. As a result, hydrogen was efficiently generated, and finally, 80% of the theoretical value (about 1360 ml at room temperature) of the hydrogen generation amount when the total amount of the hydrogen generating substance reacted could be extracted.

  At this time, the maximum temperature of the outer surface (can surface temperature) of the polyethylene container 1, that is, the reaction temperature of the hydrogen generating material was 95 ° C. at the maximum. It was also confirmed that hydrogen was continuously generated at a substantially constant generation rate, and generation of hydrogen stopped after a few minutes when water supply was stopped.

(Comparative Example 4)
Hydrogen was produced in the same manner as in Example 10 except that the water used was the same as that used in Comparative Example 3, and the amount of hydrogen generated was measured.

  As a result, only 68% of the theoretical value (about 1360 ml at room temperature) of the hydrogen generation amount when the total amount of the hydrogen generating substance reacted was finally extracted. This is probably because the dissolved sulfuric acid ion concentration of the water used was too high, and poorly water-soluble sulfates were deposited in the vicinity of the water supply port 6 so that the water could not be supplied smoothly.

(Example 11)
As shown in FIG. 6, a PEFC 200 and a fuel cartridge 300 are connected to form a fuel cell power generation system, and hydrogen produced in the same manner as in Example 10 in the fuel cartridge 300 is supplied to the negative electrode of the PEFC 200 to generate a power generation test. Went. The fuel cartridge 300 is the same as that shown in FIG. 5 (the one used in Example 10). FIG. 6 is a cross-sectional view showing the configuration of the fuel cell power generation system. However, in order to facilitate understanding of each component, a part of the component is hatched indicating that it is a cross section. Not.

The PEFC 200 used in the fuel cell power generation system shown in FIG. 6 includes an MEA (electrode / electrolyte integrated body) 100, a sealing material 15 (silicon rubber) for suppressing gas leakage, and a positive current collector 13 (vertical 7 mm, horizontal 7 mm, 2 mm in height) and a negative electrode current collector plate 14 (7 mm in length, 7 mm in width, 2 mm in height). And the electrode (E-TEK "LT140E-W", Pt amount: 0.5 mg / cm < ² >) which apply | coated Pt carrying | support carbon on the carbon cloth was used for the positive electrode and negative electrode of MEA100. Further, “Nafion 112 (trade name)” manufactured by DuPont was used for the solid electrolyte membrane. The electrode area was 10 cm ² . The positive electrode current collector plate 13 is provided with air holes 13a for taking oxygen from the atmosphere into the positive electrode. The negative electrode current collector plate 14 is provided with a hydrogen introduction hole 14a for taking in hydrogen generated in the fuel cartridge into the negative electrode. As the positive electrode current collector plate 13, the negative electrode current collector plate 14, the positive electrode lead wire 16 and the negative electrode lead wire 17, SUS304 plated with gold was used.

  The PEFC 200 and the fuel cartridge 300 are connected via the hydrogen outlet pipe 18, and the hydrogen produced by the fuel cartridge 300 is supplied to the PEFC 200 through the hydrogen outlet pipe 18.

As a result of the above power generation test, it was found that a high output of 200 W / cm ² was obtained at room temperature, which was effective as a hydrogen supply method for a small-sized and portable fuel cell.

It is a fragmentary sectional view which shows typically the structural example of the hydrogen production apparatus which can be used for implementation of the hydrogen production method of this invention. It is sectional drawing which shows typically the structural example of the hydrogen production apparatus (fuel cartridge) which can be used for implementation of the hydrogen production method of this invention. It is a fragmentary sectional view which shows typically the other structural example of the hydrogen production apparatus which can be used for implementation of the hydrogen production method of this invention. It is a graph which shows the particle size distribution of the hydrogen generating substance used in the Example. It is sectional drawing which shows typically the structure of the fuel cartridge used in Example 10 and Comparative Example 4. FIG. It is sectional drawing which shows typically the structure of the fuel cell power generation system used in Example 11. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydrogen generating substance storage container 3 Water storage container 5 Water supply pipe 8 Hydrogen outlet pipe 12 Gas-liquid separation part 200 Solid polymer fuel cell

Claims (14)

80% by mass or more of particles containing at least one metal selected from the group consisting of aluminum, silicon, zinc, magnesium, and an alloy mainly composed of one or more of these metal elements and having a particle size of 100 μm or less Containing hydrogen generating materials; and
A hydrogen production method, wherein hydrogen is generated by reacting with water having a dissolved sulfate ion concentration of 700 ppm or less and an ionic conductivity at 25 ° C. of 10 to 2200 μS / cm.   The water to be reacted with the hydrogen generating substance consists of calcium ion, magnesium ion, sodium ion, potassium ion, vanadium ion, germanium ion, carbonate ion, hydrogen carbonate ion, chloride ion, nitrate ion, citrate ion and silicate ion. The method for producing hydrogen according to claim 1, comprising at least one ion selected from the group.   The water to be reacted with the hydrogen generating substance has a dissolved sodium ion concentration of 3 to 410 ppm, a dissolved chloride ion concentration of 5 to 610 ppm, and is substantially free from other dissolved ions. The method for producing hydrogen according to 1.   The water to be reacted with the hydrogen generating substance has a dissolved magnesium ion concentration of 2 to 25 ppm, a dissolved sulfate ion concentration of 8 to 100 ppm, and substantially does not contain other dissolved ions. The hydrogen production method as described.   The water to be reacted with the hydrogen generating substance has a dissolved sodium ion concentration of 3 to 460 ppm, a dissolved citrate ion concentration of 5 to 1260 ppm, and substantially does not contain other dissolved ions. The method for producing hydrogen according to 1.   The method for producing hydrogen according to any one of claims 1 to 5, wherein the hardness of water to be reacted with the hydrogen generating substance is 0.06 to 1500 mg / L.   The hydrogen generating material contains 60% by mass or more of at least one metal selected from the group consisting of aluminum, silicon, zinc, magnesium and an alloy mainly composed of one or more of these metal elements. The method for producing hydrogen according to any one of 1 to 6.   The method for producing hydrogen according to any one of claims 1 to 7, wherein an average particle size of the hydrogen generating substance is 0.1 to 30 µm.   The method for producing hydrogen according to any one of claims 1 to 8, wherein the hydrogen generating substance has a scale-like shape having a thickness of 0.1 to 5 µm.   The method for producing hydrogen according to any one of claims 1 to 9, wherein a heat generating material that generates heat by reacting with water at room temperature is used together with a hydrogen generating substance. A hydrogen generating substance storage container for storing a hydrogen generating substance and reacting the hydrogen generating substance with water, a water storage container for storing water to be supplied to the hydrogen generating substance storage container, and the water storage container A hydrogen production apparatus having a water supply pipe for supplying water to the hydrogen generating substance containing container from
The method for producing hydrogen according to claim 10, wherein the heat generating material is arranged unevenly in the hydrogen generating substance storage container.   The hydrogen production method according to claim 11, wherein the unevenly distributed portion of the heat generating material is in the vicinity of the mouth portion of the water supply pipe.   A hydrogen generating substance storage container for storing a hydrogen generating substance and reacting the hydrogen generating substance with water, a water storage container for storing water to be supplied to the hydrogen generating substance storage container, and the water storage container A water supply pipe for supplying water to the hydrogen generating substance storage container, a gas-liquid separation part for separating the water and hydrogen mixture discharged from the hydrogen generating substance storage container, and the gas-liquid separation part The hydrogen production method in any one of Claims 1-12 using the hydrogen production apparatus which has a mechanism which returns the water isolate | separated by (1) to the said water storage container.   The method for producing hydrogen according to claim 11, wherein a heat insulating material is arranged on the outer periphery of the hydrogen generating substance storage container.

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