JP2011122202A - Alloy for hydrogen generation and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an alloy for hydrogen generation which is easily treatable, generates hydrogen only when being contacted with water, stably continues to generate a hydrogen gas for a long time, and can improve the efficiency of the hydrogen generation. <P>SOLUTION: The problem is solved by providing an alloy for hydrogen generation made of a solidified alloy produced by: a first step of heating a first metal including aluminum, a second metal including at least one kind of metal selected from zinc, magnesium and silicon and a third metal including a low melting point metal with a melting point of ≤230°C to a temperature equal to or more than the melting point of aluminum to obtain a molten alloy including the first to third metals; and a second step of bringing the molten alloy into contact with a solid material, and cooling it to obtain the solidified alloy. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a hydrogen generating alloy.

  Conventionally, as a method for generating hydrogen, (1) a partial oxidation method or reforming method in which a hydrocarbon such as natural gas or petroleum is reacted with oxygen, air or steam at a high temperature, and (2) a thermal decomposition reaction with water and carbon. A method to be used, (3) a method of dissolving a metal in an acid, and the like are known. However, in the methods (1) and (2), CO and the like are by-produced together with hydrogen, so that high-purity hydrogen cannot be obtained. In the method (3), since an acid is required, handling is difficult. There are problems such as.

  In recent years, methods other than the above have been reported in which water is used as a hydrogen source and this is reacted with aluminum to obtain hydrogen. Aluminum is lightweight and can be stored stably without igniting or rusting in the air. In addition, there is an advantage that hydrogen gas is generated by reacting with neutral water. However, since aluminum has a property of forming a passive film on the surface in air, there is a problem that it hardly reacts with water at room temperature.

  In order to overcome such problems, Patent Document 1 devised a method of generating hydrogen by applying a strong force with a compression spring in water and wearing aluminum with an electric motor to expose fresh aluminum metal. Has been.

  Further, as disclosed in Patent Document 2, a method has been devised in which water in an acidic or alkaline state is brought into contact with aluminum to extract hydrogen.

  On the other hand, it has been reported that aluminum is subjected to some chemical / physical treatment, thereby making the aluminum reactive with water while maintaining the original stable properties of aluminum.

  For example, in Patent Document 3, when a thin film is prepared by rapidly cooling a molten alloy of Al—Bi at a cooling rate of 10000 ° C./sec, the Al—Bi alloy thin film has high activity against water, It has been reported that it reacts continuously to generate hydrogen.

  Patent Document 4 discloses that a fired composite in which metal oxide particles or powder is baked on an aluminum surface in a vacuum or under an inert gas atmosphere has a performance of generating hydrogen gas by contact with water. It has been reported.

  Further, in Patent Document 5, when a metal material is obtained by pulverizing aluminum or an aluminum alloy in a mixed solvent containing water and an organic solvent, the metal material efficiently generates hydrogen by contact with water. It has been reported.

  Patent Document 6 discloses a method in which a solid of aluminum metal is polished to expose atomic aluminum, and indium or gallium is immersed in liquid form to form a hydrogen generating alloy.

  Patent Document 7 discloses a method of making a hydrogen generating alloy by diffusing at least one of Al, Mg, and Zn into a large excess of low melting point alloy (gallium, indium, etc.).

  Further, Patent Document 8 includes a first metal containing one or more of Al, Zn, and Mg, and a second metal selected from Ga, Cd, In, Sn, Sb, Hg, Pb, and Bi. A first step of obtaining a molten alloy by melting at a temperature equal to or higher than the melting point of the first metal, contacting the molten alloy formed by the first step with water, cooling and solidifying, and A second step of obtaining a solidified alloy having a hydroxide derived from the first metal formed on the surface thereof, and the first metal and the second metal both react with water to generate hydrogen. Is disclosed.

JP 2004-123517 A JP 2005-200823 A Japanese Patent Publication No. 7-62198 JP 2005-162552 A JP 2007-254256 A JP 2002-161325 A JP 2003-12301 A International Publication 2008/004428 Pamphlet

  Each of the above-described prior arts is a useful method, but there are the following problems.

  First, as is apparent from the method of Patent Document 1, the apparatus is large. Further, the fresh aluminum surface must always be exposed by the rotation of the motor, which is not necessarily advantageous in terms of energy. Furthermore, tap water cannot be applied as water, and there is a restriction that pure water must be used.

  In the method of Patent Document 2, in order to obtain hydrogen continuously, a large amount of a strong acid or strongly basic aqueous solution is required. That is, the advantage of aluminum that it reacts with neutral water under mild conditions cannot be fully utilized.

  On the other hand, the methods of Patent Documents 3 to 8 are useful as a method for obtaining hydrogen by reacting aluminum with neutral water, but the alloy production process as a premise thereof is complicated.

  In Patent Document 3, an alloy for generating hydrogen with good performance is manufactured by rapidly cooling a molten alloy of Al—Bi at a cooling rate of 10000 ° C./sec or more, but this requires a large-scale apparatus. It is. Moreover, since a thin film can be obtained, the amount of alloy obtained is small and the handling is somewhat troublesome although the apparatus is large.

  The method of Patent Document 4 requires a complicated process of baking a metal oxide on the aluminum surface in a vacuum or in an inert gas atmosphere.

  The method of Patent Document 5 requires a special process in which aluminum is finely pulverized in a “water / organic solvent” mixed solvent.

  The method of Patent Document 6 is a method in which a solid aluminum substrate is partially polished to expose atomic aluminum, which is preferably immersed in molten metal under reduced pressure conditions to form an alloy, which is complicated. As the production scale increases, it takes a long time to produce the alloy.

  The method of Patent Document 7 requires a large excess of expensive indium and gallium, and a small amount of aluminum, which is problematic in terms of production efficiency.

  On the other hand, the method of Patent Document 8 is an excellent method by which a molten alloy of a metal such as aluminum having a specific composition is used as a raw material, and can be easily produced by simply bringing it into contact with water and cooling it. It is. Tap water is sufficient as water to be used, and the obtained alloy for generating hydrogen can also be stored in the air. The alloy produced in this way can start a hydrogen generation reaction simply by contacting with water, and can stably obtain hydrogen gas over a long period of time. However, in this method, competition of reaction (hydrogen generation) between a metal (aluminum or the like) and water is inevitable during the process of cooling the molten alloy in contact with water. For this reason, as soon as cooling is completed, the alloy must be immediately pulled out of the water in order to prevent further generation of hydrogen. Although this operation does not pose a problem in small-scale alloy production, there is a concern that the operation becomes complicated because hydrogen gas is flammable as the production scale increases.

  As described above, various inventions for obtaining hydrogen by reacting aluminum with water have been made so far, but there is still room for improvement from the viewpoint of easy operation.

  Accordingly, an object of the present invention is to provide a hydrogen generating alloy that can generate hydrogen gas safely, highly efficiently, and stably, without requiring special processing such as miniaturization, and a method for producing the same.

  As a result of intensive studies based on the above problems, the present inventors have found that a first metal containing aluminum, a second metal containing at least one metal selected from zinc, magnesium or silicon, and a melting point of 230 ° C. or lower. Adopting a “ternary alloy” containing a third metal containing a low-melting-point metal that is heated to a temperature of 660 ° C. or higher to obtain a molten alloy containing the first to third metals, By bringing the molten alloy into contact with a “solid material” and cooling to obtain a solidified alloy, a hydrogen generating alloy having high hydrogen generation ability (an alloy that generates hydrogen by reaction with water) can be obtained very simply. The present invention has been completed.

That is, the present invention
A first metal comprising aluminum;
A second metal comprising at least one metal selected from zinc, magnesium or silicon;
A third metal including a low melting point metal having a melting point of 230 ° C. or lower;
Is heated to a temperature equal to or higher than the melting point of aluminum to obtain a molten alloy containing the first to third metals;
A second step of bringing the molten alloy into contact with a solid material while maintaining a molten state and cooling to obtain a solidified alloy; and
An alloy for hydrogen generation made of the solidified alloy produced by the method is provided.

The present invention also provides
A first metal comprising aluminum;
A second metal comprising at least one metal selected from zinc, magnesium or silicon;
A third metal including a low melting point metal having a melting point of 230 ° C. or lower;
First step of obtaining a molten alloy by heating to a temperature equal to or higher than the melting point of aluminum;
A second step of bringing the molten alloy into contact with a solid material while maintaining a molten state and cooling to obtain a solidified alloy; and
The manufacturing method of the alloy for hydrogen generation which consists of the said solidification alloy containing this is provided.

Furthermore, the present invention provides
Provided is a hydrogen generation method including a third step of bringing the hydrogen generation alloy according to any one of the above into contact with water.

  In each of the above inventions, based on the first metal, the second metal is contained in an amount of 0.1% by mass to 100% by mass, and the third metal is contained in an amount of 0.1% by mass to 100% by mass. This is one of the preferred embodiments of the present invention.

  In each of the above inventions, it is one of the preferred embodiments of the present invention that the low melting point metal is one or more of tin, bismuth, indium, gallium, lead, cadmium, and antimony.

  In each of the above inventions, in the second step, the solid material is also in contact with the molten alloy in a state of being in contact with the refrigerant and being cooled by the refrigerant. is there.

  The alloy for hydrogen generation of the present invention is a ternary alloy that essentially includes the above-mentioned “first metal”, “second metal”, and “third metal”. The present invention is characterized in that the ternary alloy is heated to a melting point of aluminum (at 660 ° C. under normal pressure conditions) or higher and then cooled by contacting with a “solid material”. .

  That is, regardless of the contact with such a “solid material”, even if it is allowed to cool in the air, or is directly cooled by liquid by pouring liquid nitrogen, the hydrogen generating ability of the obtained solidified alloy is obtained. Is low (see comparative example). On the contrary, it has been clarified that the solidified alloy obtained by cooling with the contact with the “solid material” dramatically increases the hydrogen generation ability (specifically, the utilization efficiency of aluminum).

  In the present invention, a ternary alloy including “first metal”, “second metal” and “third metal” must be used. Even if a molten alloy lacking “second metal” or “third metal” is subjected to the same “cooling by contact with a solid material”, a solidified alloy having sufficient hydrogen generation ability cannot be obtained. .

  According to the present invention, a complicated process as in the above-mentioned patent document can be avoided, and a hydrogen generating alloy can be obtained by an unexpectedly simple operation of “contact with a solid”. For example, as in Patent Document 3, extremely rapid cooling is not necessary, and it is sufficient that the molten alloy is directly brought into contact with the cold solid material. In addition, since “water” is not used during the cooling operation, the competition of the hydrogen generation reaction during the cooling process, which is seen in Patent Document 8, does not need to be a concern in the present invention.

  According to the present invention, a hydrogen generating alloy having an excellent hydrogen generating ability is provided by a very simple operation. The alloy for hydrogen generation obtained by this method can be stored safely even in the air, and hydrogen can be obtained quickly and with high aluminum utilization efficiency simply by pouring water into it.

  Hereinafter, the present invention will be described in more detail.

  The hydrogen generating alloy of the present invention includes three different first metals (which may be referred to as “Metal A”), second metals (which may be referred to as “Metal B”), and An “ABC” alloy containing a third metal (sometimes referred to as “Metal C”). That is, “Metal A” contains aluminum, “Metal B” is a metal containing at least one metal selected from zinc, magnesium or silicon, and “Metal C” has a melting point of 230 ° C. or lower. It is a metal containing a melting point metal.

  Here, as the “metal B”, any of the above-mentioned three kinds of metals can be suitably employed. However, since zinc exhibits a particularly high effect even in a relatively small amount, zinc is one of particularly preferable ones. .

  As the “metal C”, any metal or alloy having a melting point equal to or lower than that of tin (230 ° C.) can be used. In particular, any one or more metals of tin, bismuth, indium, gallium, lead, cadmium, and antimony or alloys made of two or more types are preferable. Furthermore, it is more preferable to use a low melting point metal having a melting point of 100 ° C. or lower because the rate of hydrogen generation per unit time generated by the reaction with water increases. Among these, tin is particularly inexpensive, and it is particularly preferable that “metal C” contains tin because an alloy for generating hydrogen with excellent performance can be produced even in a small amount. However, since tin alone has a melting point of 230 ° C., in order to lower the melting point and improve the hydrogen generation performance, it is preferable to use other metals in combination as an alloy. “Sn—Bi—In” alloy is an example of such a suitable “metal C”. For example, as the composition of the “Sn—Bi—In alloy”, “Sn is 10 to 25% by mass, Bi is 40 to 70% by mass, and In is 15 to 40% by mass” is one of the preferable ones.

  There are no particular restrictions on the ratio of metal A, metal B, and metal C. However, as a result of intensive studies, the present inventors have found the following important findings.

  When the alloy for hydrogen generation of the present invention is brought into contact with boiling water (100 ° C.), not only metal A (aluminum) but also a part of what is shown as metal B (zinc, magnesium), metal C (low melting point) (Metal) reacts with water to generate hydrogen (in contrast, metal A, metal B, and metal C alone do not easily generate hydrogen even when in contact with boiling water). If attention is paid only to “a hydrogen generation amount in the single batch”, it is advantageous that all of the metals A to C react with water.

  However, especially, metal C is an expensive metal, and once it reacts with water and enters a highly oxidized state, it takes a load to recover and reuse.

  In view of such a situation, the inventors tried to contact the ternary alloy having the composition of the present invention with “water having a temperature lower than the boiling state”. As a result, it was found that metal A (aluminum) reacts with water to generate hydrogen with high efficiency, while metal B and metal C remain unreacted and almost all remains as a solid. Of these, the knowledge that metal C (low melting point metal) remains unreacted (zero-valent metal) is particularly important. Metal C has a melting point of 230 ° C. or lower, and particularly preferably an alloy having a melting point of 100 ° C. or lower (see Examples). That is, after the hydrogen generation step, the metal C is easily converted into a liquid by performing relatively little heating, and can be easily separated from other metals by physical separation means such as filtration and decantation. The separated metal C can be mixed with the metal A and the metal B as they are, and can be reused in the production of the next batch of hydrogen generating alloy. By adopting this method, the most expensive metal C can be recycled many times, and the metal A (aluminum) can be selectively consumed for hydrogen generation.

  The temperature of the “water that is lower than the boiling state” is generally 10 ° C. or higher and 90 ° C. or lower. If the water temperature is low, the hydrogen generation rate is low, and the hydrogen generation rate increases as the water temperature rises. Therefore, the temperature may be properly used depending on the application, but is preferably 20 to 80 ° C, more preferably 50 to 70 ° C. It is.

  In this way, the third step (hydrogen generation reaction) is performed using “water having a temperature lower than that in the boiling state” to selectively consume metal A (aluminum) and other metals (particularly metal C). ) Is recovered and reused, the inventors have found that a satisfactory amount of hydrogen generation can be obtained with a specific composition of a relatively large amount of metal A and a relatively small amount of metal B and metal C. Specifically, the content of the metal B is preferably 0.1% by mass or more and 100% by mass or less based on the metal A (that is, the same mass or less as the metal A). Furthermore, it was found that even if the content of metal B exceeds 10% by mass based on metal A, it is difficult to expect further increase in the hydrogen generation rate. Considering these, it is particularly preferable that the content of the metal B is 0.1% by mass or more and 10% by mass or less based on the metal A.

  Regarding the content of metal C (the total amount when the metal C is an alloy of a plurality of metals), the hydrogen generation rate tends to increase rapidly when the content is 0.1% by mass or more with respect to the metal A. Is recognized. As mentioned above, when using `` water at a temperature lower than the boiling state '', the low melting point metal itself does not participate in the direct reaction, so the amount of hydrogen generated per mass of the hydrogen generating alloy is reduced. The amount is preferably 0.1% by mass or more and 100% by mass or less with respect to the metal A, and more preferably 10% by mass or more and 50% by mass or less considering the hydrogen generation efficiency per mass of the hydrogen generating alloy.

  To summarize the above facts, in the third step, “water having a temperature lower than that in the boiling state (usually 10 to 90 ° C., preferably 20 to 80 ° C., particularly preferably 50 to 70 ° C.)” is used, and metal Using an alloy containing 0.1% to 10% by weight of metal B and 10% to 50% by weight of metal C, based on A, has a high hydrogen generation capacity (availability of aluminum ) And a relatively expensive metal C can be easily recycled, which is one of the preferred embodiments of the present invention. In this case, the aluminum component in the alloy selectively reacts with water to form aluminum hydroxide, while the other components remain in the system as a zero-valent metal.

  In addition, it does not prevent making the alloy of said each composition react with "boiled water (water higher than 90 degreeC)." In this case, although depending on the reaction time, in addition to metal A (aluminum), both metal B and metal C react with water to generate hydrogen. However, in this case as well, since the metal that is most likely to react with water (and is light and inexpensive) is metal A (aluminum), the metal composition having a large relative amount of metal A is from the viewpoint of increasing the hydrogen generation rate. This can be said to be a preferred embodiment.

The present invention
[First step]
A first metal comprising aluminum;
A second metal comprising at least one metal selected from zinc, magnesium or silicon;
A third metal including a low melting point metal having a melting point of 230 ° C. or lower;
Is heated to a temperature equal to or higher than the melting point of aluminum to obtain a molten alloy containing the first to third metals.
[Second step]
The step of bringing the molten alloy into contact with a solid material while maintaining a molten state and cooling the molten alloy to obtain a solidified alloy.
The invention of the “hydrogen generating alloy” produced by the two steps and the invention of the “method for producing the hydrogen generating alloy”.

And furthermore,
[Third step]
It is an invention of a “hydrogen generation method” including a third step of bringing the hydrogen generating alloy produced by the first and second steps into contact with water.

  Moreover, at least metal C can also be collect | recovered by giving a [recovery step] after completion | finish of [3rd step].

  In the present specification, specific embodiments will be described below in the order of “first step” to “third step” and “collection step”.

First, the “first step” will be described.
The “first step” can be carried out by introducing the first, second and third metals into a heat-resistant container and heating them to a melting point of aluminum or higher to melt them. As the order of melting the metals, the respective metals may be heated separately and mixed after melting, or may be melted after premixing. Either order does not affect the hydrogen generating ability of the final hydrogen generating alloy, so it is usually convenient and preferable to melt after premixing.

  Air can be preferably used as the atmosphere during the heat treatment. An inert gas (such as nitrogen) can be used, but such a special atmosphere need not be set.

  The heating temperature needs to be higher than the melting point of aluminum (660 ° C.). It is desirable to continue heating until the aluminum is fully melted. In the subsequent “second step”, it is important to bring the molten alloy obtained in the “first step” into contact with the solid material while maintaining the molten state. It is a preferred embodiment to heat to above ° C.

  As described above, the melting point of metal C is 230 ° C. or less, and among metals B, zinc has a melting point of 420 ° C. and magnesium has a melting point of 650 ° C., both of which are lower than aluminum. Therefore, by heating to 660 ° C. or higher, the “ABC alloy” becomes liquid as a whole.

  As for silicon, the melting point of a single substance is 1410 ° C., which is higher than the melting point of aluminum, but as shown below, aluminum and silicon form a eutectic mixture.

  Therefore, even when silicon is used as the metal B, if the silicon component is approximately 25% by mass or less based on the first metal, heating to 660 ° C. or higher can result in “ABC alloy”. "Becomes liquid as a whole. Only when the silicon content further increases and exceeds the liquidus concentration of silicon at a certain temperature, the entire silicon component is not melted and is partially precipitated. Although the performance of the alloy itself does not deteriorate even in the precipitated form, the heating temperature may be a liquid of silicon because the solidification process in the subsequent “second step” may cause inconvenience in terms of formability. It is desirable that the temperature be higher than the phase line.

  The upper limit of the heating temperature is not particularly limited, but since there is no merit even if the temperature is too high, it is preferably 1300 ° C. or less, more preferably 1100 ° C. or less from the viewpoint of the capacity of the heating equipment. . When zinc is used as the second metal, the boiling point of zinc (907 ° C.) or less is preferable because volatilization of the zinc component can be suppressed, and the load on the equipment can be reduced.

  The molten metal obtained by heating in the first step becomes a homogeneous molten alloy if the respective components are sufficiently mixed. Therefore, the molten metal can be subjected to the subsequent second step after being made homogeneous by stirring or the like. preferable.

  Next, the “second step” will be described.

  The “second step” is a process in which the molten alloy obtained in the “first step” is cooled by bringing it into contact with a solid material while maintaining a molten state to obtain a solidified alloy.

  In this step, “making contact with the solid material while maintaining the molten state of the molten alloy” is important in producing an alloy having an excellent hydrogen generating ability. That is, it is preferable that the molten alloy obtained by the “first step” is immediately subjected to the “second step” (before being cooled). It is preferable to cool the molten alloy by quickly spreading the cooling heat of the solid material to the molten alloy. When the molten alloy is allowed to cool in the air, for example, or solidified by a method of applying liquid nitrogen even at a low temperature, the original hydrogen generating ability cannot be obtained. It is assumed that the cooling effect is not sufficient in the alloy, and the second and third components are phase-separated during solidification. However, in this step, for example, a cooling rate as high as that in Patent Document 3 is not required, and therefore it is not necessary to provide a large cooling mechanism or extremely thin the solidified alloy.

  Examples of the method of contacting the solid material in this step include a method of bringing a molten metal into contact with the solid material and applying a load to the solid material. Specifically, as shown in FIG. 1, an alloy for hydrogen generation having a good hydrogen generation ability can be obtained by bringing a flat plate made of a solid material into contact with a molten metal, compressing it, and solidifying it. Assuming an industrial mass production process, as shown in FIG. 2, the molten metal is poured out from the container containing the molten metal and compressed by a twin roll (solid material) to solidify the molten metal. A method is mentioned as desirable.

  As the temperature of the solid material, the temperature of the solid material is usually 100 ° C. or lower, preferably 50 ° C. or lower, and more preferably 25 ° C. or lower. When these solid materials come into contact with the molten metal, the heat of the molten alloy is transferred to the solid material. During this cooling step, it is preferable that the temperature of the solid material stably keeps the temperature range. For example, in the case of a solid material brought into contact with “ice water” described later, it can be stably maintained at around 0 ° C., which is one of the particularly preferred embodiments.

  In order to keep the temperature of the solid material at such a low level, a method of bringing the solid material into contact with a refrigerant is effective. For example, in the apparatus shown in FIG. 1, the opposite side of “the surface of the solid material in contact with the molten alloy” is contacted with water, ice water, dry ice, acetone contacted with dry ice, cold ethylene glycol, cold brine, liquid nitrogen, or the like. By doing so, the solid material can always be kept at a low temperature. In the apparatus shown in FIG. 2, the twin roll maintained at a low temperature is always melted by circulating the refrigerant continuously or intermittently inside the twin roll (that is, the side opposite to the surface in contact with the molten alloy). It is possible to contact the metal.

  In particular, when an alloy is produced on a large scale, a hydrogen generating alloy having excellent performance can be stably produced by using ice water or a refrigerant having a temperature lower than that. The type of refrigerant to be used can be appropriately determined according to the knowledge of those skilled in the art according to the characteristics of the apparatus.

  From the above, the temperature of the solid material is approximately −196 ° C. (liquid nitrogen temperature) or higher and 100 ° C. or lower.

  In order to ensure excellent hydrogen generation capability, it is desirable to perform rapid cooling with a solid material. Specifically, in FIGS. 1 and 2, the thickness of the molten alloy after applying a load (in the direction of load) The thickness of the molten metal (“d” in the figure) is preferably within 10 mm, and more preferably within 5 mm in order to allow the cooling heat to rapidly penetrate into the molten alloy. The lower limit of the thickness is not particularly limited, but even if a very large load is applied and the thickness is reduced, it is difficult to further improve the hydrogen generation capability. More preferred.

  In FIG. 2, a plurality of twin rolls can be set in order to enhance the cooling effect. However, cooling can also be achieved by lowering the rotational speed of the twin rolls, lowering the temperature of the refrigerant circulating in the interior, or increasing the load applied to the molten alloy from the twin rolls ("d" in the figure is reduced accordingly). It is possible to increase the effect. Depending on the scale of the alloy manufacturing process and the like, each device may be combined as appropriate.

  The material of the solid material is not particularly limited as long as it has a melting point equal to or higher than the temperature of the molten metal (heating temperature in the first step), but 10 W / mK for rapidly solidifying the molten metal. It is desirable to use one having the above thermal conductivity. As a specific material, a metal material is preferable from the viewpoint of thermal conductivity, and examples thereof include iron, copper, and stainless steel. Among them, stainless steel that is chemically stable and durable even at high temperatures is particularly preferable.

  The atmosphere during cooling may be in air as in the first step.

  The hydrogen generating alloy obtained by the above method can be stably stored without impairing the hydrogen generating ability in dry air. On the other hand, when stored in a humid atmosphere for a long period of time, it may react with moisture and generate hydrogen gas, which may reduce the amount of hydrogen generated per alloy mass in the subsequent hydrogen generation process. Therefore, it is not preferable to store in humid air for a long time.

  Next, the “third step” will be described.

  The “third step” is a step of generating hydrogen gas by reacting the hydrogen generating alloy produced in the second step with water. There is no restriction | limiting in particular about the kind of water to be used, and even if it uses ultrapure water or tap water, there is no remarkable difference in the hydrogen generation | occurrence | production behavior. Therefore, it is actually preferable from the economical viewpoint to use tap water or industrial water.

  Although the temperature of the water to be contacted may be any temperature of 0 ° C. or more and 100 ° C. or less, as described above, it is usually 10 to 90 ° C., preferably 20 to 80 ° C., particularly preferably 50 to 70 ° C. It is. Adopting a temperature of 50 to 70 ° C. is one of preferred embodiments because it makes it possible to obtain hydrogen gas at a high rate and stably suppress the reaction of metals B and C.

  In these temperature ranges, metal A (aluminum) shows good reactivity with water, whereas metal B and metal C are virtually non-reactive with water and remain zero-valent metal. The In the XRD chart of the recovered alloy after completion of the third step, only the peak attributed to aluminum hydroxide was detected as the metal oxide, and peaks indicating oxides or hydroxides were observed for the other metal components. I couldn't. (See FIG. 3). As described above, when the “third step” is performed under a condition in which only the metal A (aluminum) is selectively reacted, particularly, the expensive “metal C” is recovered after the hydrogen generation step is completed. It is particularly preferable because it can be reused without reduction treatment.

  The amount of water added may be equal to or greater than the reaction equivalent with respect to the aluminum content in the hydrogen generating alloy. Assuming that this alloy is a hydrogen source for fuel cells, the higher the total amount of hydrogen generated from the total mass of the alloy and water, the better. 1 to 5 reaction equivalents. When the amount of water is around one reaction equivalent, the capacity of the water is relatively small. Therefore, in order to control the temperature of the water with respect to the heat of reaction, the water is appropriately cooled or the rate of water addition is adjusted. It may be preferable to do this.

  Although it is possible to generate hydrogen even when the amount of water is less than one reaction equivalent, it is not preferable because the effective utilization rate of aluminum is reduced when the amount is less than 0.7 reaction equivalent, especially 0.5 reaction equivalent. .

  On the other hand, when production efficiency is not particular (for example, in the case of a small-scale apparatus), it is not prevented to use a large excess of water (for example, 100 reaction equivalents, 1000 reaction equivalents) than the above.

  As the solidified alloy used in the “third step”, the solidified alloy lump obtained in the “second step (cooling process)” can be used as it is. However, it is preferable to pulverize the solidified alloy to a certain particle size in advance because hydrogen generation is stable.

  Finally, the “recovery step” which is an optional step will be described. “Recovery step” refers to a process of recovering an alloy remaining in water after the completion of the “third step”.

  As already mentioned, when boiling water (100 ° C.) is used in the “third step”, metals B and C, in addition to metal A (aluminum), are also recovered because at least part of them react with water. All of the metals A, B, and C thus converted have been converted into hydroxides and the like, and a reduction treatment is required for use in the preparation of the next batch of alloys.

  On the other hand, when “water having a temperature lower than boiling water” is used in the “third step”, the metals B and C remain as unreacted zero-valent metals as described above. For this reason, for example, the zero-valent metal can be separated from the reaction product aluminum hydroxide by using a difference in melting point. In particular, since the metal C is an alloy having a boiling point of 230 ° C. or less, the metal C becomes a liquid only by performing a relatively slight heating. The metal C that has become liquid can be easily recovered in an unreacted state by subjecting it to conventional means such as filtration or decantation, and can be reused for the preparation of alloys for the next batch. For this reason, when the “recovery step” is performed, the object of the present invention can be achieved more preferably.

To sum up the above,
By using 10 to 90 ° C. water as the water in the third step,
In the third step, substantially only aluminum is selectively reacted with water, and
After the third step, the used metal solid remaining in the water is recovered,
The method for generating hydrogen, which includes a step of recovering at least metal C from the metal solid, is mentioned as a particularly preferred embodiment of the present invention in that expensive metal C can be repeatedly reused.

In particular, in this embodiment,
In addition to the above advantages, it is high to use an alloy containing 0.1% by mass to 10% by mass of metal B and 10% by mass to 50% by mass of metal C based on metal A. It is mentioned as a more preferable embodiment of the present invention in that hydrogen generation ability (availability of aluminum) can be achieved.

[Example]
EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to this Example.

  To 5.0 g of aluminum, 0.1 g of zinc was mixed in a graphite crucible and melted in an electric furnace heated to 750 ° C. Thereafter, in the molten aluminum-zinc mixture, a Sn—Bi—In low-melting alloy (Sn: 17.3% by mass, Bi: 57.5% by mass, In: 25.2% by mass; melting point: 78.8 ° C. ) 2.0 g was introduced and stirred with a graphite rod.

  Thereafter, the molten mixture was poured onto an alumina plate and then compressed by a stainless steel plate cooled with liquid nitrogen and cooled (see FIG. 1). By compacting in this way, a lump of solidified alloy having a thickness of 2 to 3 mm was obtained. Thereafter, the solidified alloy was put into 20 ml of tap water at 60 ° C., and the hydrogen generation rate was measured.

  As a result, the hydrogen generation rate after 5 minutes from the start of the reaction was 49.1 cc / min. (A value obtained by dividing the total amount of hydrogen generated for 5 minutes from the start by the reaction time (5 minutes), converted to 0 ° C. and 1 atm. The same applies hereinafter). The amount of hydrogen gas generated by the hydrogen generation reaction 48 hours after the start of the reaction was 5.77 NL (NL is the number of liters converted to 0 ° C. and 1 atm. The same applies hereinafter). It was. The utilization efficiency of aluminum calculated from the amount of hydrogen generation was 93%. The amount of hydrogen generated per mass of the alloy was 0.81 NL.

  After the generation of hydrogen was completed, the solids that were submerged in the water were collected, homogenized, and measured by X-ray diffraction measurement. The result is shown in FIG. As described above, only a peak due to aluminum hydroxide was observed, and a peak indicating a bond between another metal and oxygen was not observed. That is, it was found that Al selectively reacted with water.

  0.01 g of zinc was mixed with 5.0 g of aluminum in a graphite crucible and melted in an electric furnace heated to 750 ° C. Thereafter, in the molten aluminum-zinc mixture, a Sn—Bi—In low-melting alloy (Sn: 17.3% by mass, Bi: 57.5% by mass, In: 25.2% by mass; melting point: 78.8 ° C. ) 2.0 g was introduced and stirred with a graphite rod.

  Thereafter, the molten mixture was poured onto an alumina plate and then compressed by a stainless steel plate having a diameter of 2 inches and a thickness of 1 cm which was cooled with liquid nitrogen and cooled. By compacting in this way, a lump of solidified alloy having a thickness of 2 to 3 mm was obtained. Thereafter, the solidified alloy was put into 20 ml of tap water at 60 ° C., and the hydrogen generation rate was measured.

  As a result, the hydrogen generation rate after 5 minutes from the start of the reaction was 10.1 cc / min. Met. The amount of hydrogen gas generated by the hydrogen generation reaction 48 hours after the start of the reaction was 5.29 NL. The utilization efficiency of aluminum calculated from the amount of hydrogen gas generated was 85%. The amount of hydrogen generated per mass of the alloy was 0.75 NL.

  In this embodiment, the metal B (zinc) is a small amount of 0.2% by mass of the metal A (aluminum). For this reason, the utilization efficiency of aluminum is slightly lower than that of Example 1, but still maintains a high level of 85%.

  To 5.0 g of aluminum, 0.1 g of zinc was mixed in a graphite crucible and melted in an electric furnace heated to 750 ° C. Thereafter, in the molten aluminum-zinc mixture, a Sn—Bi—In low-melting alloy (Sn: 17.3% by mass, Bi: 57.5% by mass, In: 25.2% by mass; melting point: 78.8 ° C. ) 2.0 g was introduced and stirred with a graphite rod.

  Thereafter, the molten mixture was poured onto an alumina plate and then compressed by a 2 inch diameter, 1 cm thick stainless steel plate cooled with 100 g of ice water (0 ° C.) and cooled. By compacting in this way, a lump of solidified alloy having a thickness of 2 to 3 mm was obtained. Thereafter, the solidified alloy was put into 20 ml of tap water at 60 ° C., and the hydrogen generation rate was measured.

  As a result, the hydrogen generation rate after 5 minutes from the start of the reaction was 40.8 cc / min. Met. The amount of hydrogen gas generated by the hydrogen generation reaction 48 hours after the start of the reaction was 5.60 NL. The utilization efficiency of aluminum calculated from the amount of hydrogen gas generated was 90%. The amount of hydrogen generated per mass of the alloy was 0.79 NL.

  In the present embodiment, the temperature of the solid material is 0 ° C., which is higher than other embodiments (cooling with liquid nitrogen). However, the utilization efficiency of 90% is maintained, which can be said to be one of the particularly preferable embodiments from the viewpoint of industrial implementation.

To 5.0 g of aluminum, 0.1 g of zinc was mixed in a graphite crucible and melted in an electric furnace heated to 750 ° C. Thereafter, in the molten aluminum-zinc mixture, a Sn—Bi—In low-melting alloy (Sn: 17.3% by mass, Bi: 57.5% by mass, In: 25.2% by mass; melting point: 78.8 ° C. ) 2.0 g was introduced and stirred with a graphite rod.
Thereafter, the molten mixture was poured onto an alumina plate and then compressed by a 2 inch diameter, 1 cm thick copper plate cooled by liquid nitrogen and cooled. By compacting in this way, a lump of solidified alloy having a thickness of 2 to 3 mm was obtained. Thereafter, the solidified alloy was put into 20 ml of tap water at 60 ° C., and the hydrogen generation rate was measured.

  As a result, the hydrogen generation rate 5 minutes after the start of the reaction was 51.3 cc / min. Met. The amount of hydrogen gas generated by the hydrogen generation reaction 48 hours after the start of the reaction was 5.84 NL. The utilization efficiency of aluminum calculated from the amount of hydrogen generation was 94%. The amount of hydrogen generated per mass of the alloy was 0.82 NL.

  In this embodiment, a copper plate is used in place of stainless steel as a cooling plate. The obtained aluminum utilization efficiency is as high as that in Example 1, and it is understood that the material of the solid material for cooling does not affect the performance of the hydrogen generating alloy.

To 5.0 g of aluminum, 0.1 g of magnesium was mixed in a graphite crucible and melted in an electric furnace heated to 750 ° C. Thereafter, in the molten aluminum-zinc mixture, a Sn—Bi—In low-melting alloy (Sn: 17.3% by mass, Bi: 57.5% by mass, In: 25.2% by mass; melting point: 78.8 ° C. ) 2.0 g was introduced and stirred with a graphite rod.
Thereafter, the molten mixture was poured onto an alumina plate and then compressed by a stainless steel plate having a diameter of 2 inches and a thickness of 1 cm which was cooled with liquid nitrogen and cooled. By compacting in this way, a lump of solidified alloy having a thickness of 2 to 3 mm was obtained. Thereafter, the solidified alloy was put into 20 ml of tap water at 60 ° C., and the hydrogen generation rate was measured.

  As a result, the hydrogen generation rate 5 minutes after the start of the reaction was 33.2 cc / min. Met. The amount of hydrogen gas generated by the hydrogen generation reaction 48 hours after the start of the reaction was 5.21 NL. The utilization efficiency of aluminum calculated from the amount of hydrogen generation was 84%. The amount of hydrogen generated per mass of the alloy was 0.73 NL.

  In this embodiment, the metal B is changed from zinc to magnesium, but the utilization efficiency of aluminum is maintained at a high level of 84%.

  5.0 g of aluminum was mixed with 0.1 g of silicon in a graphite crucible and melted in an electric furnace heated to 1000 ° C. Thereafter, in the molten aluminum-zinc mixture, a Sn—Bi—In low-melting alloy (Sn: 17.3% by mass, Bi: 57.5% by mass, In: 25.2% by mass; melting point: 78.8 ° C. ) 2.0 g was introduced and stirred with a graphite rod.

  Thereafter, the molten mixture was poured onto an alumina plate and then compressed by a stainless steel plate having a diameter of 2 inches and a thickness of 1 cm which was cooled with liquid nitrogen and cooled. By compacting in this way, a lump of solidified alloy having a thickness of 2 to 3 mm was obtained. Thereafter, the solidified alloy was put into 20 ml of tap water at 60 ° C., and the hydrogen generation rate was measured.

  As a result, the hydrogen generation rate after 5 minutes from the start of the reaction was 19.8 cc / min. Met. The amount of hydrogen gas generated by the hydrogen generation reaction 48 hours after the start of the reaction was 4.75 NL. The utilization efficiency of aluminum calculated from the amount of hydrogen generated was 76%. The amount of hydrogen generated per mass of the alloy was 0.67 NL.

  In this example, the metal B was used in place of zinc instead of silicon, but the utilization efficiency of aluminum is still 76%, which is still at a high level.

  2.0 g of zinc was mixed with 5.0 g of aluminum in a graphite crucible and melted in an electric furnace heated to 750 ° C. Thereafter, in the molten aluminum-zinc mixture, a Sn—Bi—In low-melting alloy (Sn: 17.3% by mass, Bi: 57.5% by mass, In: 25.2% by mass; melting point: 78.8 ° C. ) 2.0 g was introduced and stirred with a graphite rod.

  Thereafter, the molten mixture was poured onto an alumina plate and then compressed by a stainless steel plate having a diameter of 2 inches and a thickness of 1 cm which was cooled with liquid nitrogen and cooled. By compacting in this way, a lump of solidified alloy having a thickness of 2 to 3 mm was obtained. Thereafter, the solidified alloy was put into 20 ml of tap water at 60 ° C., and the hydrogen generation rate was measured.

  As a result, the hydrogen generation rate after 5 minutes from the start of the reaction was 47.1 cc / min. Met. The amount of hydrogen gas generated by the hydrogen generation reaction 48 hours after the start of the reaction was 5.74 NL. The utilization efficiency of aluminum calculated from the amount of hydrogen generation was 92%. The amount of hydrogen generated per mass of the alloy was 0.64 NL.

  In the present embodiment, a relatively large amount of metal B (zinc), 40% by mass with respect to metal A (aluminum), is used. As a result, the utilization factor of aluminum was 92%, which was the same value as in Example 1. However, the amount of hydrogen generated per mass of the alloy is reduced by the amount of metal B.

To 5.0 g of aluminum, 0.1 g of zinc was mixed in a graphite crucible and melted in an electric furnace heated to 750 ° C. Thereafter, in the molten aluminum-zinc mixture, a Sn—Bi—In low-melting alloy (Sn: 17.3% by mass, Bi: 57.5% by mass, In: 25.2% by mass; melting point: 78.8 ° C. ) 5.0 g was introduced and stirred with a graphite rod.
Thereafter, the molten mixture was poured onto an alumina plate and then compressed by a stainless steel plate having a diameter of 2 inches and a thickness of 1 cm which was cooled with liquid nitrogen and cooled. By compacting in this way, a lump of solidified alloy having a thickness of 2 to 3 mm was obtained. Thereafter, the solidified alloy was put into 20 ml of tap water at 60 ° C., and the hydrogen generation rate was measured.

  As a result, the hydrogen generation rate was 49.1 cc / min. Met. The amount of hydrogen gas generated by the hydrogen generation reaction 48 hours after the start of the reaction was 5.80 NL. The utilization efficiency of aluminum calculated from the amount of hydrogen generation was 93%. The amount of hydrogen generated per mass of the alloy was 0.57 NL.

  In this embodiment, a relatively large amount of metal B (zinc), which is 100% by mass with respect to metal A (aluminum), is used. As a result, the utilization factor of aluminum was 93%, which was the same value as in Example 1. However, the amount of hydrogen generated per mass of the alloy is reduced by the amount of metal C.

[Comparative Example 1 (alloy without metal B)]
5.0 g of aluminum was melted in an electric furnace heated to 750 ° C. Then, Sn-Bi-In based low melting point alloy (Sn: 17.3 mass%, Bi: 57.5 mass%, In: 25.2 mass%; melting point: 78.8 ° C) 2.0 g in molten aluminum And stirred with a graphite rod.

  Thereafter, the molten mixture was poured onto an alumina plate and then compressed by a stainless steel plate having a diameter of 2 inches and a thickness of 1 cm which was cooled with liquid nitrogen and cooled. By compacting in this way, a lump of solidified alloy having a thickness of 2 to 3 mm was obtained. Thereafter, the solidified alloy was put into 20 ml of tap water at 60 ° C., and the hydrogen generation rate was measured.

  As a result, the hydrogen generation rate after 5 minutes from the start of the reaction was 0.035 cc / min. Met. The amount of hydrogen gas generated by the hydrogen generation reaction 48 hours after the start of the reaction was 0.50 NL. The utilization efficiency of aluminum calculated from the hydrogen generation amount was 8%. The amount of hydrogen generated per mass of the alloy was 0.07 NL.

  As described above, when an alloy was prepared by the same method as in each example without using metal B (zinc), the hydrogen generation performance was poor.

[Comparative Example 2 (alloy without metal C)]
To 5.0 g of aluminum, 0.1 g of zinc was mixed in a graphite crucible and melted in an electric furnace heated to 750 ° C. Thereafter, the molten mixture was poured onto an alumina plate and then compressed by a stainless steel plate having a diameter of 2 inches and a thickness of 1 cm which was cooled with liquid nitrogen and cooled. By compacting in this way, a lump of solidified alloy having a thickness of 2 to 3 mm was obtained. Thereafter, the solidified alloy was put into 20 ml of tap water at 60 ° C., and the hydrogen generation rate was measured.

  As a result, generation of hydrogen was not recognized. Thus, when an alloy was prepared by the same method as in each example without using metal C (low melting point metal), the hydrogen generation performance was poor.

[Comparative Example 3 (Alloy produced by cooling in a nitrogen atmosphere)]
To 5.0 g of aluminum, 0.1 g of zinc was mixed in a graphite crucible and melted in an electric furnace heated to 750 ° C. Thereafter, in the molten aluminum-zinc mixture, a Sn—Bi—In low-melting alloy (Sn: 17.3% by mass, Bi: 57.5% by mass, In: 25.2% by mass; melting point: 78.8 ° C. ) 2.0 g was introduced and stirred with a graphite rod.
Thereafter, the molten mixture was cooled and solidified in a nitrogen atmosphere at room temperature together with the crucible. Thereafter, the solidified alloy was put into 20 ml of tap water at 60 ° C., and the hydrogen generation rate was measured.

  As a result, the hydrogen generation rate after 5 minutes from the start of the reaction was 0.02 cc / min. Met. The amount of hydrogen gas generated by the hydrogen generation reaction 48 hours after the start of the reaction was 0.29 NL. The utilization efficiency of aluminum calculated from the amount of hydrogen generation was 5%. The amount of hydrogen generated per mass of the alloy was 0.04 NL.

  Thus, unlike each Example, when the alloy for hydrogen generation was manufactured by standing-cooling in nitrogen atmosphere, the hydrogen generation performance was unsatisfactory. Presumed that the original performance of this alloy could not be exhibited because the cooling rate of the molten alloy was low because the contact with the solid material was not performed and the second and third components were phase-separated. Is done.

[Comparative Example 4 (alloy cooled with liquid nitrogen)]
To 5.0 g of aluminum, 0.1 g of zinc was mixed in a graphite crucible and melted in an electric furnace heated to 750 ° C. Thereafter, in the molten aluminum-zinc mixture, a Sn—Bi—In low-melting alloy (Sn: 17.3% by mass, Bi: 57.5% by mass, In: 25.2% by mass; melting point: 78.8 ° C. ) 2.0 g was introduced and stirred with a graphite rod.
Thereafter, the molten mixture was poured into 500 cc of liquid nitrogen and cooled. Thereafter, the solidified alloy was put into 20 ml of tap water at 60 ° C., and the hydrogen generation rate was measured.

  As a result, the hydrogen generation rate after 5 minutes from the start of the reaction was 1.1 cc / min. Met. The amount of hydrogen gas generated by the hydrogen generation reaction 48 hours after the start of the reaction was 0.54 NL. The utilization efficiency of aluminum calculated from the amount of hydrogen generation was 9%. The amount of hydrogen generated per mass of the alloy was 0.08 NL.

  Thus, although a slight performance improvement was recognized as compared with Comparative Example 2, unlike in each Example, the hydrogen generation performance of the hydrogen generation alloy produced by cooling with liquid nitrogen was poor. Despite the fact that the medium to be contacted is liquid nitrogen at −196 ° C., sufficient hydrogen generation ability was not obtained because in the case of liquid nitrogen, a film of nitrogen gas is formed between the surface of the molten metal and liquid nitrogen. It is assumed that this is because of insufficient heat transfer.

[Reference Example 1 (alloy prepared by rapid cooling by contact with water)]
4.0 g of zinc was mixed with 4.0 g of aluminum in a graphite crucible and melted in an electric furnace heated to 750 ° C. Thereafter, in the molten aluminum-zinc mixture, a Sn—Bi—In low-melting alloy (Sn: 17.3% by mass, Bi: 57.5% by mass, In: 25.2% by mass; melting point: 78.8 ° C. ) 2.0 g was introduced, stirred with a graphite rod, and then poured into 300 cc of ultrapure water for rapid cooling. Ten seconds after being put into water, the solidified alloy was pulled up from the water and dried in an air atmosphere. Thereafter, the alloy was put into 20 ml of ultrapure water at 60 ° C., and the hydrogen generation rate was measured.

  As a result, the hydrogen generation rate was 52.1 cc / min. Met. The utilization efficiency of aluminum by the hydrogen generation reaction 48 hours after the start of the reaction was 93%, and the hydrogen generation amount was 4.63 NL.

  The alloy produced in this reference example shows excellent hydrogen generation performance (aluminum utilization efficiency of 93%). However, a small amount of hydrogen was observed during the cooling operation with water. For this reason, it has been necessary to quickly pull out the cooled and solidified alloy from the water so that the generation of hydrogen does not proceed as much as possible.

[reference data]
The SEM observation result of the solidified alloy obtained by the 2nd step of Example 1, and the composition analysis result by EDX are shown in FIG. 4, FIG. As a comparison, the SEM observation result of the solidified alloy obtained by the method of Comparative Example 3 and the composition analysis result by EDX are shown in FIGS. 4 and 5, the aluminum and the low melting point metal component are dispersed in the micron order region, whereas in FIGS. 6 and 7, the low melting point metal component is not observed and the aluminum and the inside thereof are contained. Only the dissolved zinc component was observed. From the above, it can be seen that in the solidified alloy cooled in a nitrogen atmosphere, the aluminum phase and the low melting point metal phase are phase-separated in a wide range. The low melting point metal not detected in FIG. 7 is presumed to be deposited as a low melting point metal phase outside the observation region.

  Hydrogen gas can be obtained safely by reacting the alloy produced by this method with water. Hydrogen obtained by this method is extremely pure and does not contain impurity gas such as carbon monoxide. For example, when used as a fuel for a fuel cell, it is possible to generate electricity with high efficiency while preventing electrode deterioration and the like. it can. Further, the present invention can be used for an internal combustion engine such as a hydrogen engine that operates using a combustion reaction with oxygen.

  Therefore, the fuel cell using the hydrogen gas obtained by the present invention is used as a power source for mobile portable equipment, and the internal combustion engine using the hydrogen gas obtained by the present invention is used as a vehicle drive source or a generator power source. It becomes possible.

FIG. 1 illustrates a method of cooling a molten alloy in contact with a solid material. FIG. 2 illustrates a method of cooling a molten alloy in contact with a twin-roll solid material. FIG. 3 shows the result of XRD measurement after collecting used alloy remaining in water after the hydrogen generation reaction of Example 1 was completed. Thus, diffraction peaks attributed to aluminum hydroxide and diffraction peaks of metallic tin and metallic indium were observed. FIG. 4 shows the result of SEM observation of the solidified alloy prepared in Example 1. FIG. 5 shows the result of composition analysis by EDX between the line segments A and B shown in FIG. It was observed that the aluminum phase and the additive metal phase were dispersed on the micron order. FIG. 6 shows the results of SEM observation of the solidified alloy prepared in Comparative Example 3. FIG. 7 shows the result of composition analysis by EDX between the line segments A and B shown in FIG. Although the zinc component was dissolved in the aluminum phase, it was observed that almost no added low melting point metal was present. It is presumed that the low melting point metal not detected in the figure is precipitated as a low melting point metal phase outside the observation region.

Claims (10)

A first metal comprising aluminum;
A second metal comprising at least one metal selected from zinc, magnesium or silicon;
A third metal including a low melting point metal having a melting point of 230 ° C. or lower;
Is heated to a temperature equal to or higher than the melting point of aluminum to obtain a molten alloy containing the first to third metals;
A second step of bringing the molten alloy into contact with a solid material while maintaining a molten state and cooling to obtain a solidified alloy; and
An alloy for hydrogen generation made of the solidified alloy manufactured by: The second metal is contained in an amount of 0.1% by mass to 100% by mass based on the first metal, and the third metal is contained in an amount of 0.1% by mass to 100% by mass. Alloy for hydrogen generation. The hydrogen generating alloy according to claim 1 or 2, wherein the low melting point metal is one or more of tin, bismuth, indium, gallium, lead, cadmium, and antimony. The hydrogen generating material according to any one of claims 1 to 3, wherein in the second step, the solid material is brought into contact with the molten alloy while being in contact with a coolant and cooled. alloy. A first metal comprising aluminum;
A second metal comprising at least one metal selected from zinc, magnesium or silicon;
A third metal including a low melting point metal having a melting point of 230 ° C. or lower;
First step of obtaining a molten alloy by heating to a temperature equal to or higher than the melting point of aluminum;
A second step of bringing the molten alloy into contact with a solid material while maintaining a molten state and cooling to obtain a solidified alloy; and
A method for producing a hydrogen generating alloy comprising the solidified alloy. The second metal is contained in an amount of 0.1% by mass or more and 100% by mass or less based on the first metal, and the third metal is contained in an amount of 0.1% by mass or more and 100% by mass or less. A method for producing an alloy for hydrogen generation. The method for producing an alloy for hydrogen generation according to claim 5 or 6, wherein the low melting point metal is at least one of tin, bismuth, indium, gallium, lead, cadmium, and antimony. The hydrogen generating material according to any one of claims 5 to 7, wherein, in the second step, the solid material is brought into contact with the molten alloy in a state of being cooled by contacting with a refrigerant. Alloy manufacturing method. A method for generating hydrogen, comprising a third step of bringing the alloy for generating hydrogen according to any one of claims 1 to 4 into contact with water. By using 10 to 90 ° C. water as the water in the third step,
In the third step, substantially only the first metal is selectively reacted with water, and
After the third step, the used metal solid remaining in the water is recovered,
Recovering at least a third metal from the metal solid,
The method for generating hydrogen according to claim 9.