JP6130655B2 - Periodic table Group 1 and 2 hydride production method, production apparatus and method of use thereof - Google Patents

Description

The present invention relates to a method for producing metal hydrides belonging to Groups 1 and 2 of the periodic table, such as sodium hydride (NaH), potassium hydride (KH), calcium hydride (CaH ₂ ) and magnesium hydride (MgH ₂ ). The present invention relates to a manufacturing apparatus and a method for using the same.

  In a hydrogen society that will come in the near future, the use of hydrides such as sodium hydride is expected as a hydrogen storage material for hydrogen storage and transportation and a hydrogen generation material.

  As a method for producing such a hydride, sodium hydroxide is melted and held in an electrolytic crucible made of an oxygen ion conductive solid electrolyte, and sodium hydroxide is electrolyzed in an inert atmosphere, and only the produced oxygen is produced. By separating out of the electrolytic crucible, sodium hydride is generated in the electrolytic crucible.

JP2007-223839

  However, in this application, an electrolytic electrode such as platinum plating is formed on the inner and outer walls of an electrolytic crucible for storing and heating NaOH, and the material of the electrolytic crucible is an expensive zirconia such as yttria-stabilized zirconia with oxide ion conductivity It is made of ceramics, and a mechanism for introducing purge gas must be provided in order to discharge only oxygen after electrolysis, the apparatus is expensive, and adjustment of the material of the electrolytic crucible is complicated.

  The method for producing a hydride according to the present invention contains at least one of transition metals as a hydride holder in a sealed casing and supplies a periodic table Group 1 and Group 2 metal hydroxide as a reactant. The chemical support and the reactant were heated above the melting point and decomposition point of the reactant, and the pressure in the sealed casing was reduced to 1 atm or less.

The hydride holder is stainless steel, and the periodic table group 1 alkali metal hydroxide is at least one of sodium hydroxide (NaOH) and potassium hydroxide (KOH). The group metal hydroxide is preferably at least one of magnesium hydroxide (Mg (OH) ₂ ) and calcium hydroxide (Ca (OH) ₂ ).

  The hydride manufacturing apparatus of the present invention is housed in a hermetic casing, a reactant composed of a metal hydroxide of Groups 1 and 2 of the periodic table housed in the hermetic casing, and the reactant in the hermetic casing. A hydride holder made of at least one of transition metals, a heating device for heating the casing reactant and the hydride holder, and discharging air in the sealed casing and reducing the pressure in the casing to 1 atm or less. And a pressure reducing device for reducing the pressure. The hermetic casing is preferably formed of at least one of transition metals and also serves as a hydride holder.

  In the method of using the hydride of the present invention, the hydride produced by the production method of the present invention is housed in a tank capable of adjusting the air inflow, and water is supplied into this tank to generate hydrogen. It is preferable to supply air (oxygen) into the tank.

In the hydride production method and production apparatus of the present invention, hydroxides of Group 1 metals (alkali metals) and Group 2 metals of the periodic table such as NaOH, KOH, Mg (OH) ₂ , Ca (OH) _2, etc. In contact with a hydride support containing one or more transition metals such as stainless steel, in the case of a Group 1 metal, the melting temperature (300-350 ° C.) or in the case of a Group 2 metal, the decomposition temperature ( Ca (OH) ₂ ; 580 ° C., Mg (OH) ₂ ; 330 ° C.) or more, and by reducing the pressure inside the sealed casing, a metal hydride can be easily produced at a low cost, causing a reaction. The operation to make is also simple.

  Furthermore, in the method of using the hydride of the present invention, hydrogen can be produced by a simple operation of adding water to the produced metal hydride. Especially when oxygen is added, the exothermic reaction becomes intense and the generated heat is reduced. It can also be used.

It is a manufacturing system figure of metal hydride of the present invention. It is sectional drawing of the inner wall of the casing of the manufacturing system of FIG. It is sectional drawing of the hydrogen generation tank which shows the 1st usage method of the manufactured metal hydride. It is a perspective view of the hydride holding body for hold | maintaining a metal hydride. It is a block diagram of the hydrogen generation system which shows the 2nd usage method (vehicle-mounted) of the manufactured metal hydride. It is a perspective view of the hydride holding body accommodated in a cylindrical tank.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In Figure 1, a metal production system S ₁ hydrides of the present invention has a cylindrical closed casing 1, this closed casing 1, with the metal hydroxide as the reactant 2 is housed, A hydride holder 3 shown in FIG. 4 for adhering and holding a metal hydride is housed in a freely removable manner. The casing 1 is surrounded by a mantle heater 4 as a heating device and is heated to the melting point or decomposition point of the reactant 2, and the upper surface of the casing 1 is for discharging hydrogen generated in the casing 1. A discharge pipe 5 is fixed, and a vacuum pump 6 as a pressure reducing device is connected to the discharge pipe 5, and the inside of the casing 1 is reduced to atmospheric pressure (1 atmospheric pressure or less), preferably 0.5 atmospheric pressure by the vacuum pump 6. The following reduced pressure state is maintained.

  The hydride holder 3 is a metal element supplier during the reaction, and is preferably an austenitic type containing stainless steel, particularly nickel. For example, SUS304 (18% Cr-8% Ni-residual Fe) is used. There are two types of the sealed casing 1, and the first type is a case where the treated sealed casing 1 is used as it is as a hydrogen generation tank, and the second type is for opening and closing the upper lid 1a of the sealed casing 1. It is formed freely (for example, provided with a flange and screwed (not shown)), and after processing, the hydride holder 3 is taken out from the casing 1 and stored, for example, in a hydrogen generation tank 10 as shown in FIG. This is the case.

  In the case of the first type, it is preferable that the metal hydride 7 also adheres to the inner wall of the casing 1, and for this purpose, the material of the casing 1 is SUS304 containing transition metals (Fe, Ni, Cr). . In the case of the second type, since the inner wall of the casing 1 does not react and it is necessary to increase the durability of the casing, a nickel (Ni) material, inconel mainly composed of nickel, or a shape memory alloy can be used. . The nickel component serves as a catalyst during the reaction and does not react by itself, so that it can be used for a long time. In the case of iron, it is not impossible, but it easily oxidizes and lacks durability. The hydride holder 3 is preferably formed of “SUS304”, but it can also be made of iron. In this case, the casing 1 is poorly reacted with Ni and needs to be made of iron.

Examples of the reactant 2 include metal hydroxides of Group 1 of the periodic table such as sodium hydroxide (NaOH) and potassium hydroxide (KOH), magnesium hydroxide (Mg (OH) ₂ ), calcium hydroxide (Ca (Ca ( OH) ₂ ) and other group 2 metal hydroxides are used, and in the case of NaOH and KOH, they are heated to their melting point (300 to 350 ° C.) or higher, and Mg (OH) ₂ , Ca ( In the case of OH) ₂ , the decomposition point is 330 ° C. and 580 ° C., and it is necessary to heat to a temperature higher than this, but it is necessary to heat to 500 to 600 ° C. for an active reaction. .

When the casing 1 is heated to these temperatures, nano-order particulates scatter from the surface of the reactant 2 into the casing under the reduced pressure in the casing 1, and the hydride holder 3 and the inner wall of the casing 1. (Except for Ni), hydrogen (H ₂ ) is discharged from each reactant through the discharge pipe 5, and the remaining oxygen is hydride holder 3, casing 1 is SUS304, iron Are stored on their surfaces in a condensed form as higher-order oxide layers 8, on which the metal hydride layer 7 is formed (FIG. 2).

  Table 1 shows the types of the metal hydroxide 7 and the components of the oxide layer 8 with respect to the material of the reactant 2.

As described above, in the case of the first type, the casing 1 is used as it is as a hydrogen generator. For example, if steam or water is injected into the casing from the water supply port 9 on the upper surface of the casing 1, the metal hydride is used. Is
NaH + H ₂ O → NaOH + H ₂ ↑ (1)
KH + H ₂ O → KOH + H ₂ ↑ (2)
MgH ₂ + 2H ₂ O → Mg (OH ₂ ) + 2H ₂ ↑ (3)
CaH ₂ + 2H ₂ O → Ca (OH ₂ ) + 2H ₂ ↑ (4)
In this reaction, each reactant is produced while producing hydrogen, and this reactant produces each metal hydride by reusing.

In the case of the second type, the hydride holder 3 is taken out from the casing 1 and stored in the hydrogen generation tank 10 as shown in FIG. 3 (hydrogen use system S ₂ ). As long as the tank 10 has strength and heat resistance, the material is not limited, and the tank 10 has an openable / closable lid 10a. A water supply pipe 11 and a hydrogen discharge pipe 12 are attached to the lid 10a. Around the hydrogen generation tank 10, a heat exchange pipe 13 for taking out heat generated at the time of hydrogen generation is wound, and the heat extracted thereby is used as heat for the manufacturing system S ₁ as an auxiliary to the mantle heater 4. Can be used. At this time, in the hydrogen use system manufacturing system S ₃ , when oxygen (air) is slightly supplied together with water or water vapor into the hydrogen generation tank 10, the reaction becomes intense and a large amount of heat energy can be produced.

5, the hydrogen generation system S ₃ A hydrogen generation system S ₃ for vehicle includes a hydrogen generating tank 20 is in-vehicle, a hydride maintained as shown in FIG. 6 in the hydrogen generating tank 20 A body 21 is accommodated, and hydride is attached and held on the holding body 21 in a sealed casing (not shown) on the cylindrical body. The hydrogen generation tank 20 may be of the first type, but FIG. 5 shows the second type. The hydrogen generation tank 20 is provided with a water supply pipe 22, a hydrogen discharge pipe 23 and an air intake pipe 24. The air intake pipe 24 is provided with an opening adjusting valve. A fuel cell 27 and an electric motor 28 for rotating the wheels are connected via the motor.

  The pressure in the tank 20 is measured by a pressure gauge 29, and a water tank 30 mounted on the vehicle is connected to the water supply pipe 22. The water in the water tank 30 is supplied to a predetermined amount of hydrogen generation tank by a pump 31. 20 is sent.

  The pump 31, the opening adjustment valve 25, the pressure gauge 29, and the flow meter 26 are connected to the controller C. The controller C controls the pump 31 and the opening adjustment valve 25 by signals from the flow meter 26 and the pressure gauge 29. Thus, the amount of water and air sent into the hydrogen generation tank 20 is adjusted.

  The hydride holder reacts integrally with water and can take out hydrogen in the water and has a high hydrogen storage rate, so that it can be applied to a general hydrogen generation system in addition to a fuel cell vehicle.

DESCRIPTION OF SYMBOLS 1 ... Sealed casing 2 ... Reactant 3 ... Hydride holding body 4 ... Mantle heater 6 ... Vacuum pump 7 ... Metal hydride layer 8 ... Oxide layer 10 ... Hydrogen generation tank 20 ... Hydrogen generation tank 24 ... Air intake pipe

Claims (6)

In the sealed casing, at least one of transition metals is housed as a metal element supplier, and Group 1 and 2 metal hydroxides of the periodic table are supplied as a reactant, and the metal element supplier and the reactant are used as reactants. A method for producing a hydride of Groups 1 and 2 of the periodic table, which is heated to the melting point or the decomposition point or higher and the pressure in the closed casing is reduced to 1 atm or less. The metal element supply body is stainless steel, first Zokukin genus hydroxide the periodic table sodium hydroxide (NaOH), of potassium hydroxide (KOH), at least one, the periodic table 2 The group 1 or 2 hydride of the periodic table according to claim 1, wherein the group metal hydroxide is at least one of magnesium hydroxide (Mg (OH) ₂ ) and calcium hydroxide (Ca (OH) ₂ ). Method. A sealed casing, a reactant made of metal hydroxides of Groups 1 and 2 of the periodic table housed in the sealed casing, and housed together with the reactant in the sealed casing, at least one kind of transition metal A hydride holder, a heating device for heating the sealed casing , the reactants, and the hydride holder; and a pressure reducing device for discharging air in the sealed casing and reducing the pressure in the casing to 1 atm or less. Periodic table first and second group hydride production equipment. The said sealed casing is a periodic table 1st and 2nd group hydride manufacturing apparatus of Claim 3 which is formed from at least 1 type of a transition metal, and serves also as a hydride holding body. Hydrides manufactured by the method of claim 1 is accommodated in the air inlet adjustable tank Obtaining water supplies hydrides allowed to generate hydrogen in the tank. The hydride utilization method according to claim 5, wherein air (oxygen) is supplied into the tank.

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