Hydrogen production methods

Abstract

This invention provides a hydrogen production method that can be produced using energy-efficient methods. [Solution] The hydrogen production method comprises a reaction step in which water is reacted to obtain hydrogen in a reaction vessel 11 containing media 14 and additives by at least one of the mechanical action of contact between media 14 and the mechanical action between media 14 and the reaction vessel 11. The additives include one or more selected from nickel aluminum alloy, bismuth, tin, indium, tellurium, copper, molybdenum, niobium, vanadium, manganese, titanium, hafnium, bismuth oxide, tin oxide, indium oxide, tellurium oxide, copper oxide, molybdenum oxide, niobium oxide, vanadium oxide, manganese oxide, titanium oxide, and hafnium oxide.

Description

Technical Field

[0001] The present disclosure relates to a method for producing hydrogen.

Background Art

[0002] As methods for producing hydrogen, a method of electrolyzing water and an IS process are known. Patent Document 1 discloses a technique for producing hydrogen by the IS (Iodine-Sulfe) process in which sulfuric acid is thermally decomposed and hydrogen is extracted using an iodine aqueous solution. Specifically, a technique for suppressing heat required for separating pure hydrogen iodide not containing water in the benzene reaction in the IS process is disclosed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in conventional industrial hydrogen production methods, large-scale energy is required to electrolyze or heat the reaction vessel. Therefore, a technique capable of producing hydrogen with less energy is demanded.

Means for Solving the Problems

[0005] The method for producing hydrogen for solving the above problems includes a reaction step of reacting water to obtain hydrogen by at least one of the mechanical action due to the contact between the media and the mechanical action due to the contact between the media and the reaction vessel in a reaction vessel containing a media and an additive, and the additive includes Nickel-aluminum alloy, indium, niobium, and hafnium one or more selected from.

[0006] According to the above configuration, hydrogen is produced by the reaction of water through at least one of the mechanical effects of contact between media and the reaction vessel within the reaction vessel containing the media and additives, and the mechanical effects between the media and the reaction vessel. Therefore, there is no need to heat the reaction vessel. For this reason, hydrogen can be produced with less energy compared to methods that require heating the reaction vessel.

[0007] The additive may also contain aluminum in addition to the nickel-aluminum alloy. The molar equivalent of the additive to the water may be 1.0 molar equivalent or more. The material of the reaction vessel may be selected from stainless steel, zirconia, agate, alumina, silicon nitride, tungsten carbide, and plastic polyamide. The material of the media may be selected from stainless steel, zirconia, agate, alumina, silicon nitride, tungsten carbide, and nylon. [Effects of the Invention]

[0008] The above technological concept allows for the energy-efficient production of hydrogen. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic diagram showing the reaction apparatus in which the reaction step is carried out in the hydrogen production method of the embodiment. [Modes for carrying out the invention]

[0010] (Embodiment) The following describes one embodiment of a hydrogen production method with reference to the drawings. The reaction step in the hydrogen production method is a type of mechanochemical reaction. A mechanochemical reaction is a reaction in which the activity of reactants is increased by mechanical energy such as collisions and friction between objects.

[0011] <Reaction apparatus> As shown in Figure 1, the reaction apparatus 10 for carrying out a mechanochemical reaction is a device that can supply mechanical energy to the sample in the reaction vessel 11. The reaction apparatus 10 is a so-called planetary ball mill apparatus.

[0012] The reaction apparatus 10 comprises a plurality of reaction vessels 11. Figure 1 illustrates an example in which the reaction apparatus 10 comprises two reaction vessels 11. Each reaction vessel 11 has a reaction vessel body 12 and a lid 13. The reaction vessel body 12 opens upward. The lid 13 is attached above the reaction vessel body 12. The lid 13 closes the opening of the reaction vessel body 12. Each reaction vessel 11 has a first rotation axis C1. Each reaction vessel 11 rotates in a first rotation direction R1 about the first rotation axis C1.

[0013] The material of the reaction vessel 11 should be one that allows the media 14 to repel it and convert the kinetic energy of the media 14 into thermal energy or the like. The material of the reaction vessel 11 can be selected from, for example, stainless steel, zirconia, agate, alumina, silicon nitride, tungsten carbide, and plastic polyamide. Stainless steel is an alloy of iron, chromium, and nickel. Zirconia refers to zirconium dioxide. Alumina refers to aluminum oxide. The capacity of each reaction vessel 11 is, for example, 1 mL or more and 1000 mL or less.

[0014] The reaction apparatus 10 comprises multiple media 14. The media 14 serve as stirring media in the mechanochemical reaction. The media 14 are placed inside each reaction vessel 11. The media 14 are spherical. The diameter of the media 14 is, for example, 1 mm or more and 20 mm or less.

[0015] The material of media 14 can be any material that allows media 14 and reaction vessel 11 to repel each other, thereby converting the kinetic energy of media 14 into thermal energy or the like. Furthermore, the material of media 14 can be any material that allows media 14 to repel each other, thereby converting the kinetic energy of media 14 into thermal energy or the like. The material of media 14 can be selected from, for example, stainless steel, zirconia, agate, alumina, silicon nitride, tungsten carbide, and nylon.

[0016] The reaction apparatus 10 includes a container turntable 15. Each reaction vessel 11 is placed on the upper surface of the container turntable 15. The container turntable 15 has a second rotation axis C2. The container turntable 15 rotates in a second rotation direction R2 about the second rotation axis C2. The second rotation direction R2 is the opposite direction of rotation to the first rotation direction R1.

[0017] Each reaction vessel 11 rotates on its own axis around a first rotation axis C1 and revolves on the vessel turntable 15 around a second rotation axis C2. As a result, the media 14 inside each reaction vessel 11 moves outward due to rotation and centrifugal force. Mechanical energy is imparted to the sample inside each reaction vessel 11 by the media 14 moving outward. Although not shown in the figures, the device for rotating each reaction vessel 11 and the vessel turntable 15 is composed of a known planetary gear mechanism and an electric motor as a drive source.

[0018] The reaction apparatus 10 is configured to control the atmosphere inside each reaction vessel 11. Specifically, the reaction apparatus 10 can fill each reaction vessel 11 with a gas of a specific component. The reaction apparatus 10 can also recover the gas inside each reaction vessel 11. The supply of gas to and collection of gas into each reaction vessel 11 can be selected from known methods. For example, a specific gas can be supplied into each reaction vessel 11 through a supply pipe. In addition, the gas generated inside each reaction vessel 11 can be collected by suction through a collection pipe.

[0019] <Hydrogen production methods> The hydrogen production method includes a reaction step of reacting water to obtain hydrogen by at least one of the mechanical action caused by the contact of media 14 with each other and the mechanical action caused by the contact of media 14 with the reaction vessel 11 within the reaction vessel 11 containing media 14 and an additive. The mechanical action is, for example, one that gives mechanical energy such as collision and friction to the reactants. At least one of the mechanical action caused by the contact of media 14 with each other and the mechanical action caused by the contact of media 14 with the reaction vessel 11 is imparted to the reactants by rotating the reaction vessel 11 either自转 or公转. Hereinafter, the reaction of water by at least one of the mechanical action caused by the contact of media 14 with each other and the mechanical action caused by the contact of media 14 with the reaction vessel 11 is, for convenience, described as a mechanochemical reaction.

[0020] In the present embodiment, in the reaction step, the mechanochemical reaction proceeds by operating the reaction device 10 so that the reaction vessel 11 rotates自转 and公转 on the container turntable 15 as described above. In the reaction step, the mechanochemical reaction proceeds in an air atmosphere. That is, in the reaction step, oxygen and nitrogen are present in the reaction vessel 11. In the reaction step, two or more media 14 are placed in the reaction vessel 11. Preferably, 100 or more media 14 are placed in the reaction vessel 11.

[0021] In the reaction step, the number of rotations of the container turntable 15 per minute, that is, the revolution speed, is 50 rpm or more. Preferably, the revolution speed is 1000 rpm or more. In the reaction step, the number of rotations of the reaction vessel 11 per minute, that is, the rotation speed, is about twice the revolution speed.

[0022] The time for rotating the container turntable 15 and the reaction vessel 11 is not particularly limited as long as the mechanochemical reaction proceeds. In the reaction step, the time for rotating the container turntable 15 and the reaction vessel 11 is, for example, 25 minutes or more. The time for rotating the container turntable 15 and the reaction vessel 11 is, for example, 60 minutes or more. The time for rotating the container turntable 15 and the reaction vessel 11 may be continuous or the total of divided times. It should be noted that the Chinese characters "自转" and "公转" in the original text seem to be incorrect expressions. It is guessed that the correct ones might be "rotate" and "revolve" respectively. If this is not in line with the actual situation, please provide more accurate information for a more accurate translation.

[0023] The additive contains one or more selected from, for example, nickel-aluminum alloys, bismuth, tin, indium, tellurium, copper, molybdenum, niobium, vanadium, manganese, titanium, hafnium, oxides of bismuth, oxides of tin, oxides of indium, oxides of tellurium, oxides of copper, oxides of molybdenum, oxides of niobium, oxides of vanadium, oxides of manganese, oxides of titanium, and oxides of hafnium. Preferably, the additive is a nickel-aluminum alloy. The additive may contain aluminum in addition to the nickel-aluminum alloy.

[0024] The oxide of bismuth as an additive is bismuth(III) oxide or bismuth(V) oxide. The oxide of tin as an additive is tin(IV) oxide or tin(II) oxide. The oxide of indium as an additive is indium(III) oxide or indium(I) oxide. The oxide of tellurium as an additive is tellurium(IV) oxide or tellurium(V) oxide. The oxide of copper as an additive is copper(I) oxide or copper(II) oxide. The oxide of molybdenum as an additive is molybdenum(VI) oxide or molybdenum(IV) oxide.

[0025] The oxide of niobium as an additive is niobium(II) oxide or niobium(V) oxide. The oxide of vanadium as an additive is vanadium(IV) oxide or vanadium(V) oxide. The oxide of manganese as an additive is manganese(II) oxide, manganese(II,III) oxide, manganese(III) oxide, manganese(IV) oxide, manganese(VI) oxide, or manganese(VII) oxide. The oxide of titanium as an additive is titanium(IV) oxide or titanium(II) oxide. The oxide of hafnium as an additive is hafnium(IV) oxide.

[0026] The additive is added to the reaction vessel 11, for example, in the form of a powder, wire, foil, or the like. Alternatively, the additive may be included as part of the material of the stirring medium, such as the reaction vessel 11, media 14, or stirring rod, or it may be plated onto the surface of the media 14. The additive is preferably a nickel-aluminum alloy. The molar equivalent of the additive relative to water is 1.0 molar equivalent or more.

[0027] Molar equivalent is the ratio of the number of moles of a specified substance to the number of moles of a substance being compared. The substance being compared is, for example, water. The specified substance is, for example, an additive. In this embodiment, the specified substance may be a substance that does not change before and after the reaction, such as a catalyst, and its molar equivalent may be stated.

[0028] <Hydrogen production test using mechanochemical reaction> Examples are given below to make the structure of this disclosure more specific, but this disclosure is not limited to these examples.

[0029] The specifications of the planetary ball mill apparatus used in the following examples and comparative examples are shown in Table 1 below. The equipment used is a Fritsch Premium Line (PL-7) planetary ball mill. The ratio of rotational speed to orbital speed is -2. That is, when the reaction vessel 11 orbits once, the reaction vessel 11 rotates twice in the opposite direction. The orbital radius is 70 mm. The volume of the reaction vessel 11 is 80 mL. The diameter of the reaction vessel 11 is 48 mm. The number of media 14 is 100. The diameter of the media 14 is 5 mm.

[0030] [Table 1]

[0031] <Consideration of reaction vessel and media> For Comparative Examples 1 to 4, 10 mmol of distilled water was added to a reaction vessel 11 containing 100 media 14, and then the reaction vessel body 12 was sealed with a lid 13. In Comparative Example 1, the material of the reaction vessel 11 was SUS304. In Comparative Examples 2 to 4, the material of the reaction vessel 11 was SUS440C. In Comparative Examples 1 to 3, the material of the media 14 was SUS304. In Comparative Example 4, the material of the media 14 was SUS440C.

[0032] SUS440C is a type of martensitic stainless steel. SUS440C contains almost no nickel. SUS304 is a stainless steel that contains both chromium and nickel as components. Both SUS440C and SUS304 have the compositions specified in JIS standards. The hardness of SUS440C is higher than that of SUS304.

[0033] As described above, after adding distilled water to the reaction vessel 11 containing media 14, the vessel was stirred by rotating it at an orbital speed of 1000 rpm for 30 minutes for two sets. This allowed the mechanochemical reaction to proceed and hydrogen to be obtained. This reaction is represented by the following chemical formula (1).

[0034] [ka]

[0035] The gas in the reaction vessel 11 after stirring was collected by water displacement. The collected gas was analyzed by GC-TCD (Gas Chromatography-Thermal Conductivity Detector). The analysis results are shown in Table 2 below.

[0036] The yields shown in each table in the examples represent the ratio of the yield to the theoretical yield in the mechanochemical reaction. The theoretical yield is the theoretical maximum amount of the target substance that can be produced. The yield is the actual amount of the target substance obtained.

[0037] [Table 2]

[0038] As shown in Table 2, hydrogen was generated when water was reacted by a mechanochemical reaction. In particular, it was found that when water was reacted by a mechanochemical reaction, the hydrogen yield was higher when the material of the medium 14 was SUS304 than when the material of the medium 14 was SUS440C. Also, when both the material of the reaction vessel 11 and the material of the medium 14 were SUS304, it was found that the hydrogen yield was higher than when the material of the reaction vessel 11 was SUS440C.

[0039] <Examination of the addition of SUS304 powder> Regarding Comparative Examples 5 to 8, after putting 10 mmol of distilled water into the reaction vessel 11 containing 100 media 14 and a predetermined amount of SUS304 powder, the lid 13 was attached to the reaction vessel body 12 and sealed. In Comparative Example 5, the predetermined amount was 100 mg. In Comparative Example 6, the predetermined amount was 100 mg, and the SUS304 powder was treated with an acid. In Comparative Example 7, the predetermined amount was 300 mg. In Comparative Example 8, the predetermined amount was 500 mg.

[0040] As described above, after putting distilled water into the reaction vessel 11 containing the medium 14 and SUS304 powder, two sets of rotation at a revolution speed of 1000 rpm for 30 minutes were performed and stirred. As a result, the mechanochemical reaction proceeded and hydrogen was obtained. This reaction is represented by the following chemical formula (2).

[0041]

Chemical formula

[0042] The gas in the reaction vessel 11 after the stirring was collected by water displacement. The collected gas was analyzed by GC-TCD. The analysis results are shown in Table 3 below.

[0043]

Table 3

[0044] As shown in Table 3, when water was reacted with SUS304 powder by a mechanochemical reaction, it was found that the hydrogen yield increased with increasing amounts of SUS304 powder. Furthermore, it was found that when SUS304 powder was treated with acid, the hydrogen yield increased even with the same amount of SUS304 powder.

[0045] Furthermore, when the material of the reaction vessel 11 and the media 14 is SUS304, a small amount of wear particles may be generated due to collisions between the media 14 and the reaction vessel 11, and collisions between the media 14 themselves. From the results of Comparative Examples 5 to 8, it can be inferred that the higher hydrogen yield in Comparative Examples 1 to 3 compared to Comparative Example 4 is due to the chromium and nickel contained in SUS304 contributing to the improvement in hydrogen yield.

[0046] <Consideration of Additives 1> In Examples 1-13 and Comparative Examples 9-18, 10 mmol of distilled water was added to a reaction vessel 11 containing 100 media 14 and a predetermined molar equivalent of additive, and then the reaction vessel body 12 was sealed by attaching a lid 13. In Examples 1-13 and Comparative Examples 9-18, the material of the reaction vessel 11 and the media 14 was SUS440C.

[0047] In Example 1, 1.0 molar equivalent of copper was used as an additive. In Example 2, 1.0 molar equivalent of copper was used as an additive, and the copper was treated with acid. In Example 3, 1.0 molar equivalent of bismuth was used as an additive. In Example 4, 1.0 molar equivalent of tin was used as an additive. In Example 5, 1.0 molar equivalent of molybdenum was used as an additive. In Example 6, 1.0 molar equivalent of indium was used as an additive. In Example 7, 1.0 molar equivalent of niobium was used as an additive.

[0048] In Example 8, 1.0 molar equivalent of vanadium was used as an additive. In Example 9, 1.0 molar equivalent of vanadium was used as an additive, and the vanadium was treated with acid. In Example 10, 1.0 molar equivalent of tellurium was used as an additive. In Example 11, 1.0 molar equivalent of manganese was used as an additive. In Example 12, 1.0 molar equivalent of titanium was used as an additive. In Example 13, 1.0 molar equivalent of hafnium was used as an additive.

[0049] In Comparative Example 9, 1.0 molar equivalent of nickel was used as an additive. In Comparative Example 10, 0.1 molar equivalent of nickel was used as an additive. In Comparative Example 11, 1.0 molar equivalent of nickel was used as an additive, and the nickel was also treated with acid. In Comparative Example 12, 1.0 molar equivalent of iron was used as an additive. In Comparative Example 13, 1.0 molar equivalent of zinc was used as an additive.

[0050] In Comparative Example 14, 1.0 molar equivalent of chromium was used as an additive. In Comparative Example 15, 1.0 molar equivalent of aluminum was used as an additive. In Comparative Example 16, 1.0 molar equivalent of aluminum was used as an additive, and the aluminum was treated with acid. In Comparative Example 17, 1.0 molar equivalent of magnesium was used as an additive. In Comparative Example 18, 1.0 molar equivalent of magnesium was used as an additive, and the magnesium was treated with acid.

[0051] As described above, after adding distilled water to the reaction vessel 11 containing media 14 and additives, the mixture was stirred by rotating it at an orbital speed of 1000 rpm for 30 minutes for two sets. This allowed the mechanochemical reaction to proceed and hydrogen to be obtained. This reaction is represented by the following chemical formula (3).

[0052] [ka]

[0053] The gas in the reaction vessel 11 after stirring was collected by water displacement. The collected gas was analyzed by GC-TCD. The analysis results are shown in Table 4 below.

[0054] [Table 4]

[0055] As shown in Table 4, it was found that hydrogen can be obtained by adding water and an additive to a reaction vessel 11 containing media 14 and reacting them by a mechanochemical reaction. In particular, it was found that the yield of hydrogen was high when 1.0 molar equivalent of vanadium was used and the vanadium was treated with an acid before carrying out the mechanochemical reaction, as in Example 9. Also, it was found that the yield of hydrogen was high when 1.0 molar equivalent of magnesium was used and the magnesium was treated with an acid before carrying out the mechanochemical reaction, as in Comparative Example 18. For example, comparing Example 8 and Example 9, it can be inferred that the improvement in hydrogen yield due to acid treatment is because the passivation of the additive surface was eliminated by the acid treatment.

[0056] <Consideration of additives 2> In Example 14 and Comparative Example 19, 10 mmol of distilled water was added to a reaction vessel 11 containing 100 media 14 and 1.0 molar equivalent of an additive, and then the reaction vessel body 12 was sealed with a lid 13. In Example 14 and Comparative Example 19, the material of the reaction vessel 11 and media 14 was SUS440C. In Example 14, a nickel-aluminum alloy was used as the additive. In Comparative Example 19, alumina was used as the additive.

[0057] As described above, after adding distilled water to the reaction vessel 11 containing media 14 and additives, the mixture was stirred by rotating it at an orbital speed of 1000 rpm for 30 minutes, a process repeated three times. This allowed the mechanochemical reaction to proceed and hydrogen to be obtained. This reaction is represented by the following chemical formula (4).

[0058] [ka]

[0059] The gas in the reaction vessel after stirring was collected by water displacement. The collected gas was analyzed by GC-TCD. The analysis results are shown in Table 5 below.

[0060] [Table 5]

[0061] As shown in Table 5, it was found that the hydrogen yield was higher when a nickel-aluminum alloy was used as an additive in the mechanochemical reaction. Furthermore, it was found that the hydrogen yield was higher when using a nickel-aluminum alloy as an additive than when using alumina as an additive, as in Comparative Example 19.

[0062] <Consideration of Additives 3> In Examples 15, 16, and Comparative Examples 20-23, 10 mmol of distilled water was added to a reaction vessel 11 containing 100 media 14 and a predetermined molar equivalent of additive, and then the reaction vessel body 12 was sealed by attaching a lid 13. In Examples 15, 16, and Comparative Examples 20-23, the material of the reaction vessel 11 and media 14 was zirconia.

[0063] In Example 15, 1.5 molar equivalents of nickel-aluminum alloy were used as an additive. In Example 16, 1.0 molar equivalent of nickel-aluminum alloy and 1.0 molar equivalent of aluminum were used as additives. In Example 17, 1.0 molar equivalent of titanium(IV) oxide was used. In Comparative Example 20, 1.0 molar equivalent of alumina was used as an additive. In Comparative Example 21, 1.0 molar equivalent of alumina and 1.0 molar equivalent of barium titanate were used as additives. In Comparative Example 22, 1.0 molar equivalent of magnetite was used as an additive.

[0064] As described above, after adding distilled water to the reaction vessel 11 containing media 14 and additives, the mixture was stirred by rotating it at an orbital speed of 1000 rpm for 30 minutes, a process repeated three times. This allowed the mechanochemical reaction to proceed and hydrogen to be obtained. This reaction is represented by the following chemical formula (5).

[0065] [ka]

[0066] The gas in the reaction vessel 11 after stirring was collected by water displacement. The collected gas was analyzed by GC-TCD. The analysis results are shown in Table 6 below.

[0067] [Table 6]

[0068] As shown in Table 6, even when zirconia was used as the material for the reaction vessel 11 and media 14, hydrogen generation was confirmed when a mechanochemical reaction was carried out using additives. In particular, it was found that the hydrogen yield was high when a nickel-aluminum alloy was used as the additive for the mechanochemical reaction. Furthermore, it was found that the hydrogen yield was high when a nickel-aluminum alloy and aluminum were used as additives for the mechanochemical reaction.

[0069] <Effects of the Embodiment> (1) The hydrogen production method comprises a reaction step in which water is reacted to obtain hydrogen in a reaction vessel 11 containing media 14 and additives by at least one of the mechanical effects of contact between media 14 and the mechanical effects of contact between media 14 and the reaction vessel 11. The additive is one or more selected from nickel aluminum alloy, bismuth, tin, indium, tellurium, copper, molybdenum, niobium, vanadium, manganese, titanium, hafnium, bismuth oxide, tin oxide, indium oxide, tellurium oxide, copper oxide, molybdenum oxide, niobium oxide, vanadium oxide, manganese oxide, titanium oxide, and hafnium oxide.

[0070] According to the above configuration, hydrogen is produced by the reaction of water through at least one of the mechanical effects of contact between the media 14 and the reaction vessel 11 within the reaction vessel 11 containing the media 14 and additives, and the mechanical effects between the media 14 and the reaction vessel 11. Therefore, there is no need to heat the reaction vessel 11. For this reason, hydrogen can be produced with less energy compared to methods that require heating the reaction vessel 11.

[0071] (2) The additive includes aluminum in addition to the nickel-aluminum alloy. With this configuration, as can be seen from the results of Example 16 in Table 6, the hydrogen yield in the reaction process can be improved by adding aluminum in addition to the nickel-aluminum alloy.

[0072] (3) The molar equivalent of the additive relative to water is 1.0 molar equivalent or more. With this configuration, as can be seen from the results of Examples 1 to 17 in Tables 4 to 6, the yield of hydrogen in the reaction process can be improved.

[0073] (4) The material of the reaction vessel 11 may be one selected from stainless steel, zirconia, agate, alumina, silicon nitride, tungsten carbide, and plastic polyamide. The above materials are relatively resistant to wear. Therefore, the generation of wear particles in the reaction vessel 11 due to the mechanochemical reaction in the reaction process can be suppressed.

[0074] (5) The material of the media 14 may be one selected from stainless steel, zirconia, agate, alumina, silicon nitride, tungsten carbide, and nylon. The above materials are relatively resistant to wear. Therefore, it is possible to suppress the generation of wear particles in the reaction vessel 11 in conjunction with the mechanochemical reaction in the reaction process.

[0075] <Example of changes> The above embodiment can be implemented with the following modifications. The above embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0076] The rotation and revolution speeds in the reaction apparatus 10 are merely examples. The rotation and revolution speeds in the reaction apparatus 10 can be appropriately changed depending on the size of the reaction vessel 11, etc.

[0077] The reaction apparatus 10 may be a ball mill, a vibrating ball mill, a mixer-mill, etc. In other words, any apparatus capable of imparting mechanical energy to water and metal carbonate can be used.

[0078] The molar equivalent of the additive may be less than 1.0. Even if the molar equivalent is less than 1.0, a catalytic effect from the additive can still be expected. The additive may include metals other than aluminum in addition to the nickel-aluminum alloy. Examples of metals other than aluminum include transition metals such as nickel, iron, and zinc, or alkaline earth metals such as magnesium, calcium, and barium. In this modified example, the metal added simultaneously with the nickel-aluminum alloy may contribute to the reaction and generate hydrogen.

[0079] The material of the reaction vessel 11 is not specified. However, it is preferable that the material be resistant to abrasion when the metal carbonate and media 14 collide during the reaction process. Similarly, the material of the media 14 is not specified, but it is preferable that the material be resistant to abrasion when the media 14 collide with each other. Two or more types of media 14 made of different materials may be used as the media 14.

[0080] In the above embodiment, a structure composed of multiple objects may be integrated, or conversely, a structure composed of a single object may be divided into multiple objects. Whether or not the objects are integrated, the structure should be configured in a way that achieves the objective of the invention. [Explanation of Symbols]

[0081] 11…Reaction vessel 14…Media

Claims

1. The reaction step comprises a reaction vessel containing media and additives, in which water is reacted to obtain hydrogen by at least one of the mechanical effects of contact between the media and the mechanical effects of contact between the media and the reaction vessel, The aforementioned additive comprises one or more selected from nickel-aluminum alloy, indium, niobium, and hafnium. A method for producing hydrogen.

2. The aforementioned additive includes aluminum in addition to the nickel-aluminum alloy. A method for producing hydrogen according to claim 1.

3. The molar equivalent of the additive relative to the water is 1.0 molar equivalent or more. A method for producing hydrogen according to claim 1.

4. The material of the reaction vessel is selected from stainless steel, zirconia, agate, alumina, silicon nitride, tungsten carbide, and plastic polyamide. A method for producing hydrogen according to any one of claims 1 to 3.

5. The material of the media is selected from stainless steel, zirconia, agate, alumina, silicon nitride, tungsten carbide, and nylon. The method for producing hydrogen according to claim 4.

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