Hydrogen production device, and hydrogen production method

Abstract

To solve a problem of a low hydrogen generation ratio and carbon dioxide generation, associated with a conventional hydrogen production method.SOLUTION: A positive electrode 107 contains at least either of an iron (II) complex and an iron (III) complex, and graphite. An electrolytic solution 104 consisting of a sodium salt is filled between the positive electrode 107 and a negative electrode 108, and a separator 119a is disposed therebetween. An electrode voltage control circuit 114 is connected between the positive electrode 107 and the negative electrode 108, to apply a voltage between the electrodes, whereby the iron complex in the positive electrode 107 is oxidized and hydrogen is generated from the negative electrode 108. The generated hydrogen is collected by a gas collector 109. The positive electrode 107 is reduced by radiating light 118 thereto or by electrically connecting the positive electrode 107 with an auxiliary electrode 106.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a hydrogen production device and a hydrogen production method. [Background technology]

[0002] One method of producing hydrogen is called "reforming," in which fossil fuels are burned to produce gas, and hydrogen is extracted from that gas. However, this manufacturing process generates carbon dioxide.

[0003] There is a production method to produce hydrogen by "electrolysis," that is, by splitting water using electricity. Splitting water using electricity requires a large amount of electricity, so the power efficiency for the hydrogen produced is extremely poor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] WO2019 / 234992 [Patent Document 2] Patent Publication No. 2020-93950 Summary of the Invention [Problem to be solved by the invention]

[0005] The production method of generating hydrogen from the organic gas methane requires high temperature heating, which generates carbon dioxide. As long as organic matter is used as the raw material, the generation of carbon dioxide is unavoidable.

[0006] In the production method of electrolyzing water and generating hydrogen using a catalyst, a large amount of power is required for the electrolysis of water because the theoretical potential window of water is 1.23 V. Therefore, if hydrogen is used as an energy source, more energy than this will be used for hydrogen production. [Means for solving the problem]

[0007] The positive electrode 107 contains graphite and at least one of an iron (II) complex and an iron (III) complex. An electrolyte 104 made of a sodium salt is filled between the positive electrode 107 and the negative electrode 108, and a separator 119a is also disposed.

[0008] An electrode voltage control circuit 114 is connected between the positive electrode 107 and the negative electrode 108, and when a voltage is applied between the electrodes, the iron complex on the positive electrode 107 is oxidized, and hydrogen is generated from the negative electrode 108. The generated hydrogen is collected by a gas collector 109. When the positive electrode 107 is irradiated with light 118 or when the positive electrode 107 and the auxiliary electrode 106 are electrically connected, the positive electrode 107 is reduced. [Effects of the Invention]

[0009] Hydrogen can be easily generated with low power consumption, and can be provided in a low-cost hydrogen production device and hydrogen production method. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating a configuration of a hydrogen production device and an explanatory diagram of a hydrogen production method according to the present invention. [Figure 2] 1 is a configuration diagram of a hydrogen generator of the hydrogen production device of the present invention. [Figure 3] FIG. 2 is an explanatory diagram of a hydrogen generator of the hydrogen production device of the present invention. [Figure 4] 1 is a diagram illustrating a configuration of a hydrogen production device and an explanatory diagram of a hydrogen production method according to the present invention. [Figure 5] 1 is a configuration diagram and an explanatory diagram of a hydrogen production device according to the present invention. [Figure 6] 1 is a diagram illustrating a configuration of a hydrogen production device and an explanatory diagram of a hydrogen production method according to the present invention. [Figure 7] 1 is a diagram illustrating a configuration of a hydrogen production device and an explanatory diagram of a hydrogen production method according to the present invention. [Figure 8] 1 is a diagram illustrating a configuration of a hydrogen production device and an explanatory diagram of a hydrogen production method according to the present invention. [Figure 9]1 is a diagram illustrating a configuration of a hydrogen production device and an explanatory diagram of a hydrogen production method according to the present invention. [Figure 10] 1 is a configuration diagram of a hydrogen generator of the hydrogen production device of the present invention. [Figure 11] 1 is a diagram illustrating a configuration of a hydrogen production device and an explanatory diagram of a hydrogen production method according to the present invention. [Figure 12] 1 is a configuration diagram of a hydrogen generator of the hydrogen production device of the present invention. [Figure 13] 1 is a configuration diagram of a hydrogen generator of the hydrogen production device of the present invention. [Figure 14] 1 is a configuration diagram and an explanatory diagram of a hydrogen production device according to the present invention. [Figure 15] 1 is a configuration diagram and an explanatory diagram of a hydrogen production device according to the present invention. [Figure 16] 1 is a configuration diagram and an explanatory diagram of a hydrogen production device according to the present invention. [Figure 17] 1 is a configuration diagram and an explanatory diagram of a hydrogen production device according to the present invention. [Figure 18] 1 is a configuration diagram and an explanatory diagram of a hydrogen production device according to the present invention. [Figure 19] 1 is a configuration diagram and an explanatory diagram of a hydrogen production device according to the present invention. [Figure 20] 1 is a configuration diagram and an explanatory diagram of a hydrogen production device according to the present invention. [Figure 21] FIG. 1 is an explanatory diagram of an automobile using the hydrogen production device of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] When two electrodes are placed in water and a voltage higher than the potential window of water is applied, the water decomposes, generating hydrogen and oxygen. This is water electrolysis, and the reaction between the negative and positive electrodes is shown below. Hydrogen is produced at the negative electrode. HO + e - → 1 / 2H2+ OH - (1a) H + + e- → 1 / 2H2(1a') At the positive electrode, H2O → 1 / 2O2 + 2H ++ e- (1b) 2OH - → H2O + 1 / 2O2 + 2e - (1b') In aqueous solution, H + and OH - is in equilibrium with H + + OH - ⇔ H2O This equilibrium is the fastest reaction in aqueous solution, and the reactions 1a and 1a' and 1b and 1b' cannot be distinguished.

[0012] In acidic aqueous solutions, 1a' and 1b occur preferentially. In alkaline aqueous solutions, 1a and 1b' occur preferentially. Considering the evolution of hydrogen, 1a' has a lower reduction potential than 1a.

[0013] In other words, in an acidic aqueous solution, 1a' is preferred (1a' is the main reaction), so the reduction potential is low. On the other hand, in an alkaline solution, 1b' lowers the potential for oxygen production.

[0014] As a result, the cell voltage at which electrolysis occurs (theoretically, the applied voltage is 1.23 V) remains the same whether the solution is acidic or alkaline. However, the potential window for water varies depending on the properties of the dissolved electrolyte and the electrodes. A lead-acid battery can be applied with 2 V. The oxidation and reduction potential of water changes depending on the hydrogen ion concentration, but the potential window remains the same.

[0015] This can actually be confirmed by CV measurements of 1 mol H2SO4 aqueous solution and 1 mol NaOH aqueous solution. In other words, there is no difference in the power consumption for electrolysis whether the solution is acidic or alkaline. The structure of normal water is in the weakest state of the OH bond, and the potential window is 1.23 V.

[0016] In the present invention, hydrogen is generated without generating oxygen at the negative electrode. Therefore, the reduction potential of water is important. In other words, acidic water has a lower reduction potential, which is advantageous. Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

[0017] In the drawings illustrating the embodiments of the invention, elements having the same function or similar configuration are denoted by the same reference numerals, and descriptions thereof may be omitted. In addition, the drawings may be enlarged, reduced, or omitted.

[0018] The examples of the present invention described in this specification and drawings can be combined with each other. The examples described in this specification and drawings include the embodiment, similar forms of the embodiment, and forms combining the embodiments.

[0019] The negative electrode 108 reduces water (or hydrogen ions) to generate hydrogen (H2). The positive electrode 107 does not decompose water; instead, it oxidizes metal ions rather than generating oxygen (O2). The present invention oxidizes metal complexes. Furthermore, it can oxidize water at a lower voltage. The oxidation reaction is rapid and reversible.

[0020] Complexes of various transition metals are possible. In the present invention, it is preferred to use iron (II) and (III) complexes. For example, hexacyanoiron complexes are exemplified. Below, [Fe II (CN)6] 4- The oxidation reaction is shown below. At the positive electrode 107, [Fe II (CN)6] 4- [Fe III (CN)6] 3- It oxidizes to. [Fe II (CN)6] 4- → [Fe III (CN)6] 3- + e - E0= -0.36V (2) This reaction is reversible and occurs rapidly.

[0021] Examples of similar complexes include Fe(phen)3 (phen: phenanthroline), Fe(bipy)3 (bipy: bipyridine), and Fe(en)3 (en: ethylenediamine).

[0022] Reaction (2) is Fe 2+ The oxidation reaction of iron(II) and iron(III) ions is classified into low-spin and high-spin complexes depending on the spin state of the d electrons. The CN, phen, and bipy complexes mentioned above are low-spin complexes, and the complexes are very stable.

[0023] High spin complexes, e.g., [Fe(ox)3] 4- (ox: oxalic acid), as well as low-spin complexes, can also be used for the positive electrode 107. [Fe(ox)3] 4- So, [Fe(ox)3] 3- The potential between the two is 0.02 V, which allows for a lower potential for hydrogen production. However, high-spin complexes can be less stable than low-spin complexes. Fe 2+ → Fe 3+ + e - E0= -0.77V (3)

[0024] For example, [Fe II (CN)6] 4- and Fe 2+ (Actually, water molecules are coordinated to form an aqua complex) are both divalent iron ions, but the former is a low-spin complex and the latter is a high-spin complex, [Fe II (CN)6] 4- The structure is stable and it is not oxidized in the atmosphere. 2+ Although it has a high oxidation potential, it is oxidized in air to form Fe2O3 (red rust).

[0025] [Fe II (CN)6] 4- Although it may decompose in a strongly acidic aqueous solution, it does not decompose in an aqueous solution with a low pH. In fact, the salts of water-insoluble hexacyanoiron(II) complexes, such as Na2Ni[Fe II (CN)6] is used.

[0026] In an acidic aqueous solution, the combination of reactions 1a' and 1b allows the applied voltage to be lower than in an alkaline solution, which means that power consumption can be reduced.

[0027] [Fe II (CN)6] 4- Fe 3+ salts of (Fe 3+ )4[Fe II (CN)6]3 is known as Prussian blue and has long been used as a pigment. Because it contains trivalent iron ions, it has good conductivity and is suitable for electrodes. The mechanism for producing hydrogen through electrolysis is configured as follows. When a voltage is applied between the positive electrode 107 and the negative electrode 108, a reaction occurs in which (1a) and (2) are added together. HO + e - → 1 / 2H2+OH - (1a) [Fe II (CN)6] 4- → [Fe III (CN)6] 3- +e - E0= -0.36V (2) In (1a)+(2), HO + [Fe II (CN)6] 4- → [Fe III (CN)6] 3- +OH - + 1 / 2H2(4) The reduction potential of water depends on the hydrogen ions, but is approximately -0.3 V. The overall potential of (4) is -0.66 V. This potential is about half the magnitude of the potential for water electrolysis. When reaction (2) is complete, hydrogen production also stops. By controlling the voltage (current) supply, it is possible to easily control whether hydrogen is produced or not, and the amount of hydrogen produced.

[0028] Hydrogen generation / non-generation can be achieved by controlling the on / off of the switch circuit 115a, or by changing the magnitude of the current / voltage of the variable DC power supply 112a, or by controlling the polarity of the voltage and the direction of the current flow.

[0029] The embodiment of the present invention depicted in FIG. III (CN)6] 3- [Fe II (CN)6] 4- The auxiliary electrode 106 is provided to return the Fe(II) oxide to the electrolyte. The active material of the auxiliary electrode 106 is trisoxalato Fe(II) complex, [Fe(ox)3]. 4- is exemplified. The oxidation reaction of this complex is [Fe II (ox)3] 4- → [Fe III (ox)3] 3- + e- E0= -0.02V (5) Between the positive electrode 107 and the auxiliary electrode 106, [Fe III (CN)6] 3- + [Fe II (ox)3] 4- → [Fe II (CN)6] 4- + [Fe III (ox)3] 3- E0= +0.34V (6)

[0030] Because the potential of reaction (6) is positive, the reaction proceeds spontaneously, similar to the discharge of a battery. When the positive electrode 107 and the auxiliary electrode 106 are separated by a separator 119b and electrically connected to each other, the battery begins to discharge and the reaction proceeds.

[0031] The photoinduced reaction of the Fe(II) complex is explained below, citing a paper by Yutaka Fukuda et al. (Inorganic Materials, Vol. 4, May 295-304 (1997)).

[0032] When the d orbitals of a transition metal, such as Fe(II), are placed in a ligand field, the energy of the orbital is expressed in group theory symbols as t 2g Orbital and e g Fe(II) has six d electrons. All six d electrons are t 2gorbitals are called low-spin complexes.

[0033] [Fe II (CN)6] 4- and [Fe(II)(phen)3] 2+ ] (phen: 1,10-phenanthroline) is a low-spin complex. What these complexes have in common is that they are stable and have very dark colors. In other words, they have very large molar absorption coefficients. Because transitions between normal d orbitals are forbidden, the absorption coefficients range from single digits to ~10 M -1cm-1 whereas for the low-spin complexes mentioned above, it is about 10,000 times larger.

[0034] This means that t 2g Orbital and e g This cannot be explained by the transition between orbitals (dd transition). 2g There is orbital overlap between the orbital and the ligand, and by irradiating it with light (visible light), t 2g An electron transfer occurs from the orbital to the ligand.

[0035] This transition is not forbidden, so the molar extinction coefficient becomes very large. This is called a charge-transfer transition, and it means that Fe(II) is oxidized to Fe(III), which means that light (visible light) irradiation is effective for Fe(II).

[0036] The irradiation of visible light 118b is effective. Semiconductor photocatalysts, such as titanium oxide, can also decompose water to generate hydrogen. However, sunlight contains only a few percent of ultraviolet light that is effective as a photocatalyst. In the present invention, it is possible to generate hydrogen by using sunlight with high efficiency.

[0037] At the positive electrode 107, [Fe III (ox)3] 3- is highly sensitive to visible light 118 and readily undergoes photoirradiation to form [Fe II (ox)3] 4- However, the oxalate ions (ox) coordinated to the iron 2-) is oxidized and decomposed. For example, as shown in the embodiment of FIG. 8, light 118 is irradiated onto the positive electrode 107.

[0038] For example, as shown in Fig. 9, sunlight is introduced using glass fiber 503. Alternatively, the auxiliary electrode is irradiated with light using a light generator 117 such as a backlight for an LCD or the like. Alternatively, light generated from a fluorescent lamp, an ultraviolet lamp, an LED lamp, a discharge lamp, an HID lamp, an ultraviolet lamp, or the like is irradiated.

[0039] It goes without saying that when irradiating the positive electrode 107 or the like with light 118, the positive electrode 107 may be removed from the electrolyte solution 104 and then irradiated with light 118. It also goes without saying that the positive electrode 107 may be moved to another container 102 and then irradiated with light 118, as shown in FIG.

[0040] As described above, by irradiating light 118, [Fe III (ox)3] 3- is reduced to [Fe II (ox)3] 4- Naturally, [Fe III (ox)3] 3- Electrically, [Fe II (ox)3] 4- Since the redox potential is 0.02V, the power consumption is small. It goes without saying that the positive electrode 107 may be electrically changed or reduced by applying a potential difference between the auxiliary electrode 106 and the positive electrode 107 .

[0041] [Fe III (CN)6] 3- Although photoreduction is also possible with the auxiliary electrode 106, [Fe III (ox)3] 3- The photoreduction of [Fe III (ox)3] 3- The reduction reaction proceeds even when heat is applied. Therefore, it is preferable to heat the material during light irradiation.

[0042] [Fe III (CN)6] 3- When reducing by light 118, this can be achieved by irradiating the positive electrode 107 with light from a light generator 117. At the same time, it is preferable to apply heat to the positive electrode 107. A higher heating temperature is preferable, but the effect is improved at a heating temperature of 20°C or higher. It goes without saying that after a predetermined amount of hydrogen has been generated, the positive electrode 107 may be replaced with a new positive electrode 107.

[0043] As shown in FIG. 16, the replaced positive electrode 107 may be connected to an auxiliary electrode 106 of another device having an auxiliary electrode 106 to reduce the replaced positive electrode 107 . As shown in FIGS. 1 and 8, it goes without saying that the positive electrode 107 may be irradiated with light to be reduced and changed, and then reused.

[0044] As shown in Figures 6 and 7, multiple second electrodes are used, some of the multiple second electrodes are used to produce hydrogen, and unused second electrodes are reduced, thereby enabling continuous hydrogen production. The above matters are III (CN)6] 3- The present invention is not limited to the above, and can also be applied to other positive electrodes 107 and auxiliary electrodes 106.

[0045] The positive electrode 107 is made by mixing Prussian blue or hexacyanoiron(II) complex with graphite, and then coating the collector electrode with this or wrapping it around the collector electrode. When Prussian blue oxidizes, it can dissolve in the electrolyte. To prevent this, using sodium phosphate in the electrolyte can prevent the active material from dissolving. In addition to Prussian blue, any hexacyanoiron(II) complex may be used in the form of a salt. Iron(II) and iron(III) complexes are particularly preferred because they are sparingly soluble.

[0046] Maintaining the solid state improves the efficiency of oxidation-reduction. Prussian blue, (Fe 3+ )4[Fe II(CN)6]3, is hardly soluble, but when oxidized, Fe 3+ [Fe III (CV) 6 ] and dissolves in water.

[0047] NaFe 3+ [Fe II (CN)6] and Na2Ni[Fe II ]CN)6] is oxidized (iron becomes trivalent from divalent), and Fe 3+ [Fe III (CN)6] and NaNi[Fe III Even if the compound [(CN)6] is produced, it is hardly soluble in water, meaning that the electrode can always be kept in a solid state. Considering the efficiency of the electrode reaction, NaFe 3+ [Fe II (CN)6] and Na2Ni[Fe II ]CN)6] is preferred over Prussian blue. The oxidation reaction is shown below. NaFe 3+ [Fe II (CN)6] → Fe 3+ [Fe III (CN)6] + Na + + e- Na2Ni[Fe II (CN)6] → NaNi[Fe III (CN)6] + Na + + e-

[0048] The positive electrode can be Prussian blue or a related substance (iron(II) hexacyanocomplex), which preferably remains solid (insoluble in aqueous solution) in its original and oxidized state.

[0049] In reaction (2), the produced [Fe III (CN)6] 3- [Fe II (CN)6] 4- There is an electrochemical method to return it to [Fe III (CN)6] 3- is electrochemically reduced to [Fe II(CN)6] 4- To do so.

[0050] The positive electrode 107, i.e., [Fe III (CN)6] 3- The mixture of Fe and graphite is connected to the negative electrode 108 of the water-based capacitor. The reaction proceeds from the negative electrode of the capacitor to the positive electrode [Fe III (CN)6] 3- Electrons are supplied to the following reaction: For example, NaNi[Fe III (CN)6], NaNi[Fe III (CN)6]+Na + +e- → Na2Ni[Fe II (CN)6] (7)

[0051] In reaction (7), Na + Since this involves the movement of ions, the positive electrode 107 and the capacitor negative electrode 108 are separated by a cation exchange membrane as a separator 119. Alternatively, a salt bridge 121 is used to connect the two electrodes.

[0052] The separator 119 is not limited to a cation exchange membrane. For example, a hydrophilic polymer membrane or paper such as filter paper may be used. In this case, Na + Movement, OH - can move the separator.

[0053] Since the potential of reaction (7) is 0.36 V, the reaction proceeds spontaneously (energy can be extracted). The potential of the capacitor can be low (e.g., 0.3 V), but it must have enough capacity to complete reaction (7). It is preferable that the electric double layer capacitor be aqueous.

[0054] The electrolyte 104 may be any sodium (Na) salt (for example, it may be a sodium carbonate aqueous solution, similar to the positive electrode 107). Note that the energy consumption is low, but the capacity must be large.

[0055] [Fe III (CN)6] 3- was used as an auxiliary electrode, and [FeII (ox)3] 4- When reduced with, the oxidation product, [Fe III (ox)3] 3- occurs, so the original [Fe II (ox)3] 4- It needs to be returned to. In addition to the complexes, examples of combinations that cause redox reactions include a ruthenium complex and iron. Iron is particularly preferred as an example because it is inexpensive.

[0056] In one embodiment of the present invention, [Fe II (ox)3] 4- In an electric double layer capacitor, even if electrons are donated, no redox reaction occurs. There is no change in the active material. [Fe III (CN)6] 3- When is electrically reduced, the auxiliary electrode 106 is not required.

[0057] The reduction by the capacitor (by the negative electrode of the capacitor) occurs at the auxiliary electrode by reaction (6) [Fe III (ox)3] 3- It is also used in the reduction of [Fe III (ox)3] 3- If [Fe II (ox)3] 4- and [Fe III (ox)3] 3- The potential of is only 0.02 V, as shown in reaction (5), so the energy required for electrical reduction is small.

[0058] As described above, reduction by the negative electrode of an electric double layer capacitor is a new reduction method that enables the supply of electrons. Using the positive electrode 107 of the capacitor makes electrical oxidation possible.

[0059] As mentioned above, the positive electrode 107 is formed by mixing a salt of hexacyanoiron (II) complex with conductive powder such as graphite. If the salt is insoluble in water even after being oxidized to form an iron (III) complex, no separator 119 is required between the positive electrode and the negative electrode.

[0060] The positive electrode 107 is connected to the negative electrode of the capacitor (a mixture of graphite and activated carbon) via a separator. The positive electrode of the capacitor has the same components as the negative electrode of the capacitor, and is connected via the separator.

[0061] That is, the positive electrode (hexacyanoiron (II) complex), separator, capacitor negative electrode (graphite and activated carbon mixture), separator, and capacitor positive electrode (graphite and activated carbon mixture) are connected in this order.

[0062] The electrolyte may be the same for all the capacitors, but if a cation exchange membrane is used as the separator (1a) between the positive electrode and the negative electrode of the capacitor, the electrolyte of the capacitor can be changed in the same way as on the hydrogen production side.

[0063] Sodium ions are common and can move freely. When hydrogen is generated at the negative electrode 108, a difference in sodium ion concentration occurs near the negative electrode 108 and the positive electrode (e.g., hexacyanoiron(II) complex) 107. Since this causes a change in acid concentration, in the present invention, stirring fan 103 is operated to stir electrolytes 104 and 105. The hydrogen production device and method of the present invention will be described below. Figures 1, 8 and 9 are explanatory diagrams of the hydrogen production device and method of the present invention.

[0064] The hydrogen production device 201 (hydrogen generator 201) of the present invention shown in FIG. 8 includes a negative electrode 108 and a positive electrode 107. The positive electrode 107 utilizes a redox reaction of a complex. The positive electrode 107 is heated or warmed using a heater 510 or the like. The positive electrode 107 is heated or warmed directly by a heating means such as the heater 510, or indirectly via the electrolyte 104 or the like. 1 includes a negative electrode 108, a positive electrode 107, and an auxiliary electrode 106. The positive electrode 107 utilizes the oxidation-reduction reaction of the complex. There are no particular limitations on the collector electrode of the negative electrode 108. Any material may be used as long as it is not susceptible to corrosion and can be used for electrolytic reduction. It is preferable to use an aqueous solution of sodium carbonate, sodium bicarbonate, or sodium phosphate as the electrolyte 104. The buffer effect of the aqueous solution is important. The separator 119a is a cation exchange membrane. + moves freely between the electrodes, but the metal complexes are all anions and remain at their respective electrodes.

[0065] The positive electrode 107 is formed by mixing at least one of Prussian blue and a hexacyanoiron(II) complex with graphite, and then depositing, coating, applying, printing, sintering, arranging, forming, or the like on a collecting electrode. Alternatively, a mixture of at least one of Prussian blue and a hexacyanoiron(II) complex with graphite is sandwiched between the collecting electrode by deposition, coating, applying, printing, sintering, or arranging or forming. The material of the collecting electrode is not particularly limited as long as it is conductive.

[0066] When Prussian blue is oxidized, it may dissolve in the electrolyte 104. Therefore, it is preferable to keep it in the electrode. Using sodium phosphate in the electrolyte 104 can prevent the active material from dissolving.

[0067] Collector electrodes such as the negative electrode 108 may be formed or configured from stainless steel, titanium, copper, zinc, nickel, aluminum, copper, stainless steel, alloys thereof, sintered alloys, wire mesh, foam metal, ceramics, etc. Furthermore, the surface may be plated or formed with platinum, gold, silver, tin, zinc, tungsten, titanium, copper, or nickel, or an alloy combining these may be formed or disposed.

[0068] It is preferable to periodically replace the electrolyte 104. + The concentration increases. + To adjust the concentration, an electrolyte circulator 111 is operated. It is preferable to take in (inflow) the electrolyte 104 from the positive electrode 107 side and take out (outflow) it from the negative electrode 108 side. Even if the flow rate (inflow, outflow) is small, the effect is high. The same applies to the electrolyte 105, which is preferably replaced and infused at the appropriate times.

[0069] The electrolyte circulator 111 is composed of a pump (not shown) for causing the electrolyte 104 to flow out of the container 102 in which the electrolyte 104 is stored, a pump (not shown) for causing the electrolyte 104 to flow into the container 102, and the like.

[0070] The stirring fan 103 is operated to stir the Na in the electrolyte 104 in the container 102. + It is also preferable to install or place a sodium ion meter (not shown) in the electrolyte circulator 111 or the container 102 to measure and manage the sodium ion concentration at appropriate times.

[0071] An example of a sodium ion meter is one that measures sodium ions by dropping a small amount (0.3 mL or more) of sample. Sodium ion meters use a flat ion electrode, which is less susceptible to the influence of other ions, and can accurately measure ion concentration using the ion electrode method. When the value of the sodium ion meter reaches or exceeds the set value, the pump 403 and the electrolyte circulator 111 are operated to replenish and circulate the electrolyte 104.

[0072] The auxiliary electrode 106 is made of Na4[Fe II The positive electrode 107 is made by mixing Prussian blue or hexacyanoiron(II) complex with graphite and applying it to the collecting electrode, or by wrapping it around the collecting electrode. The negative electrode 108 is made of a material suitable for electrolytic reduction and is free from the risk of corrosion.

[0073] In the embodiments of the present invention, the positive electrode 107, the negative electrode 108, etc. are expressed as electrodes, but this is not limited to this. Needless to say, any configuration, shape, or structure may be used as long as it can input and output electrons or charges. In this specification and drawings, the negative electrode and the positive electrode may be expressed as the negative electrode and the positive electrode. The positive electrode 107 is constructed or formed by mixing Prussian blue, hexacyanoiron (II) complex with graphite, and applying this to a collector electrode or wrapping it around the collector electrode.

[0074] Stability can be improved by adding, mixing, or containing carbon quantum dots (CQDs) in addition to graphite or activated carbon to the positive electrode 107. In addition, the incorporation of conductive carbon or carbon quantum dots (CQDs) increases conductivity.

[0075] The separator 119 is a cation exchange membrane. The separator 119 may be made of any material and composition as long as the iron complex of the positive electrode does not decompose and dissolve. Furthermore, if the positive electrode 107 and the negative electrode 108 do not come into contact with each other, the separator 119 can be omitted.

[0076] The electrolyte 104 is exemplified by an aqueous solution of sodium salt such as an aqueous solution of sodium carbonate or sodium bicarbonate, etc. The electrolyte 104 is preferably an acidic buffer solution, and has a pH of more than 2.

[0077] The electrolyte 104 may be a mixed aqueous solution of phosphoric acid and sodium dihydrogen phosphate. The buffer solution must not have a high acid concentration. It is also necessary that the pH is not too low. Acetic acid, citric acid, etc. may also be used. The electrolyte 105 of the auxiliary electrode 106 may be, for example, sodium oxalate.

[0078] Variable DC power supply 112a is connected between terminal electrode 202b and terminal electrode 202a of negative electrode 108. Variable DC power supply 112a is configured to be able to generate any voltage in the range of 0 V to 10 V. It is also possible to vary the magnitude and direction of the current that flows.

[0079] When the switch circuit 115a is turned on, a current flows between the negative electrode 108 and the positive electrode 107, and hydrogen is generated. The voltage value of the variable DC power supply 112 is adjusted or changed as necessary. The hydrogen (H2) generated at the negative electrode 108 is collected by the gas collector 109 and stored in the gas reservoir 120 via the pipe 110.

[0080] The present invention relates to sodium (Na) salts, e.g., NaCO 3、 Electrodes are placed in an aqueous solution (weakly alkaline solution) containing NaHCO3 or Na3PO4. For example, the first electrode may be made of platinum, copper, aluminum, or the like, and the second electrode may contain Prussian blue or a similar hexacyanoiron(II) complex. A current or voltage is applied between the negative electrode 108 and the positive electrode 107 to produce hydrogen.

[0081] At the positive electrode 107 containing the hexacyanoiron(II) complex, iron(II) is oxidized to iron(III) as hydrogen is produced. There are various methods for reducing iron(III) to iron(II). For example, as shown in the examples of Figures 16 and 17, the positive electrode 107 may be removed from the aqueous solution and bonded to the auxiliary electrode 106, or may be bonded directly to the auxiliary electrode 106 in the aqueous solution. Alternatively, the positive electrode 107 may be irradiated with light. Examples of regeneration methods include the following.

[0082] 1. An auxiliary electrode 106 filled with graphite and activated carbon is used as the third electrode. The used third electrodes are joined together via a separator (hydrophilic polymer film) 119b.

[0083] The electrolyte is the aforementioned buffer solution (NaH2PO4, etc.). A current is applied at a low applied voltage of 0.1 V to 0.2 V. The iron (III) at the second electrode is reduced to iron (II), and the second electrode is regenerated.

[0084] Positive vacancies (holes) are generated in the third electrode, but the anions disperse within the electrode and the holes disappear. Once the holes disappear, the electrode can be reused as the third electrode. However, there is no problem if the holes remain.

[0085] 2. The negative electrode of a charged water-based capacitor (the active materials of both the negative and positive electrodes are a mixture of graphite and activated carbon) is used as the third electrode. The second electrode and the third electrode are joined after use.

[0086] The bonding method can be either direct bonding through a separator or through a salt bridge. Upon bonding, a current flows and a maximum voltage of 0.36 V is generated. At the second electrode, iron is reduced from (III) to (II).

[0087] 3. As the third electrode, iron(II) oxalate complex ([Fe II (ox)3] 4- , ox: oxalate ion). A battery is formed between the second and third electrodes and regenerated. The electromotive force is 0.34V.

[0088] After playing, [Fe III (ox)3] 3- [Fe II (ox)3] 4- must be reduced to [Fe III (ox)3] 3- is self-reduced by sunlight to form [Fe II (ox)3] 4- Return to the electrical III (ox)3] 3- [Fe II (ox)3] 4- It can also be reduced to and regenerated.

[0089] Any one of the above 1, 2, and 3 is carried out. Alternatively, any one of the above 1, 2, and 3 may be carried out in combination. Alternatively, regeneration may be carried out by irradiating the second electrode and the third electrode with light 118.

[0090] The auxiliary electrode 106 in FIG. 1, FIG. 16, etc. is made of Na4[Fe II(ox)3] is mixed with graphite and then printed, vapor-deposited, sintered, coated, or spread on the collecting electrode, or placed or sandwiched around the collecting electrode. Mixtures of these materials can also be used. The material of the collecting electrode is not particularly limited, and examples thereof include a metal material and a mixture of graphite and activated carbon. Hydrogen (H 2 ) generated at the negative electrode 108 is collected by a gas collector 109 and transferred to a gas reservoir 120 via a pipe 110 .

[0091] The stirring fan 103c directs the flow of the electrolytic solution 104b toward the gas collector 109 (for example, upward in the plane of the paper in FIG. 8), thereby increasing the efficiency of collecting the generated hydrogen. At the same time, it can stir and homogenize the sodium ions that have accumulated near the negative electrode 108. A pump that generates a water current may be used instead of the stirring fan 103.

[0092] Hydrogen embrittlement may occur in the gas collector 109 and the piping 110. Hydrogen affects metals, reducing their toughness and making them more susceptible to brittle fracture. Hydrogen embrittlement is more severe in steels with higher strength, and is particularly likely to occur in metals with high tensile strength.

[0093] The gas reservoir 120, gas collector 109, and piping 110 are subjected to a process called baking. Baking is performed to release absorbed hydrogen to prevent brittle fracture. The specific method varies depending on the metal material and the type and processing performed on it, but heating is performed at 190°C to 220°C for 2 to 24 hours. It is preferable to vapor-deposit or coat glass or an inorganic material on the inner surfaces (such as the portions that come into contact with hydrogen) of the gas reservoir 120, the gas collector 109, and the pipe 110.

[0094] The negative electrode 108 reduces water (or hydrogen ions) to generate hydrogen (H2). The positive electrode 107 does not decompose water; it oxidizes metal ions instead of generating oxygen (O2). It can be oxidized at a lower voltage than water. The oxidation reaction is rapid and reversible.

[0095] An electrode voltage control circuit 114a is connected between the negative electrode 108 and the positive electrode 107. A switch circuit 115a and a variable DC power supply 112a are disposed or installed within the electrode voltage control circuit 114a.

[0096] The variable DC power supply 112a is configured to be able to generate any voltage in the range of 0 V to 10 V. The variable DC power supply 112a is configured to be able to control the output current to a constant current.

[0097] The variable DC power supply 112a is configured to be able to vary the applied current or voltage in accordance with the amount of hydrogen generated. The variable DC power supply 112a can change the direction of current flow. The variation of the voltage or current is controlled by the control circuit 101. The positive electrode 107 can be reduced by changing the direction of current flow or the polarity of the applied voltage from the variable DC power supply 112a.

[0098] An ammeter 512a is disposed in the path through which the current flows. The ammeter 512a measures the current flowing in the path, and the measured current value and current change are sent to the control circuit 101. The control circuit 101 controls the on (closed) and off (open) of the switch circuit 115 based on the current value, etc., and changes or controls the output value of the variable DC power supply 112a.

[0099] When the switch circuit 115a is turned on, a current flows between the negative electrode 108 and the positive electrode 107, and hydrogen is generated. The voltage applied between the positive electrode 107 and the negative electrode 108 is preferably changed in accordance with the amount of hydrogen produced. The voltage or current of the variable DC power supply 112 is adjusted so that the amount of hydrogen produced per unit time falls within a predetermined range.

[0100] When a current flows between the negative electrode 108 and the positive electrode 107, sodium ions pass through the cation exchange membrane 119a. + moves freely between the electrodes, but the metal complexes are anions and remain at their respective electrodes.

[0101] When hydrogen is generated at the negative electrode, a difference in the concentration of sodium ions occurs near the negative electrode and the positive electrode (hexacyanoiron (II) complex). This causes a change in the acid concentration, so it is preferable to stir the solution with a stirring fan 103. The hydrogen collected in the gas reservoir 120 is mixed with other gases such as nitrogen gas, so hydrogen purification is performed. Although not shown in Fig. 1 etc., the present invention includes a hydrogen purifier. The hydrogen purifier uses a membrane separation method.

[0102] Membrane separation, a hydrogen purification technology, uses pressure differences to separate impurities during hydrogen production and use, obtaining highly pure hydrogen. Among separation membranes, polymer separation membrane modules are lightweight and suffer little performance degradation from water vapor. Polymer separation membrane modules contain hydrogen-compatible materials and are equipped with separation membranes with highly controlled pore structures.

[0103] 8, an electrolyte 104b is filled in a container 102. A gas collector 109 is disposed outside the container 102, and hydrogen collected by the gas collector 109 is collected in a gas reservoir 120 via a pipe 110.

[0104] The negative electrode 108 is vibrated using an ultrasonic generating element used in an ultrasonic cleaning device. The hydrogen generated on and attached to the negative electrode 108 is dispersed from the negative electrode 108, and can be efficiently collected by the gas collector 109.

[0105] By setting the stirring fan 103c in a spraying direction (from bottom to top on the paper), the hydrogen generated on and attached to the negative electrode 108 can be dispersed from the negative electrode 108, and the hydrogen can be efficiently collected by the gas collector 109.

[0106] The amount of hydrogen collected by the gas collector 109 is measured by a gas amount measuring device (gas flow meter 411). The current supplied by the variable DC power supply 112 varies depending on the amount of hydrogen measured by the gas amount measuring device (gas flow meter 411).

[0107] When the amount of hydrogen per unit time is greater than a predetermined value, the amount of current is decreased. When the amount of hydrogen per unit time is less than a predetermined value, the amount of current is increased. Note that the current value (voltage value) may be varied in accordance with the current (voltage) application time, without being related to the measured amount of hydrogen produced. Separator 119a is, for example, a cation exchange membrane through which sodium ions move.

[0108] An electrode voltage control circuit 114a is connected between the negative electrode 108 and the positive electrode 107. A switch circuit 115a and a variable DC power supply 112a are arranged in the electrode voltage control circuit 114a. The positive electrode 107 and the negative electrode 108 are separated by an ion exchange membrane 119a, and when the switch circuit 116a is turned on (closed), the hydrogen production reaction proceeds. A salt bridge (electrolyte bridge) 121 may be used between the positive electrode 107 and the negative electrode 108 instead of using the separator 119a.

[0109] 8, a light-transmitting window 504 is formed or arranged on a side surface or the like of the container 102. A light-generating device 117 is arranged outside the container 102. The light-generating device 117 is configured or arranged so that light 118 from the light-generating device 117 can be irradiated onto the positive electrode 107 of the container 102 through the light-transmitting window 504 of the container 102.

[0110] An example of the light-generating device 117 is a backlight of an LCD. The light-generating device 117 is not limited to one that generates light 118. For example, a configuration in which sunlight is guided from the outside of the container 102 using a light-guiding material (optical fiber 503) and introduced into a light-guiding plate or the like of the light-generating device 117, a configuration in which light generated by a discharge lamp (not shown) is incident into the container 102 through a transmission window 504, or a configuration in which light is directly irradiated onto the auxiliary electrode 106 and the positive electrode 107 can be exemplified.

[0111] The light generating device 117 may be disposed in the electrolyte 104 of the container 102. The light 118 is generated in the electrolyte 104. In this configuration, the light guide window (light transmitting portion) 504 of the container 102 is not necessary. FIG. 9 is an explanatory diagram of a configuration in which external light 118 a such as sunlight is guided by an optical fiber 503 and irradiated onto the positive electrode 107 .

[0112] Light 118a such as external light or sunlight is concentrated by a condenser lens 502 or a condenser (not shown) arranged on the top plate of the hydrogen generator 201. The concentrated light 118a is guided using a light guide means such as an optical fiber 503, and light 118b is irradiated onto the positive electrode 107 and the auxiliary electrode 106.

[0113] The present invention is not limited to optical fiber 503, and a mirror, prism, or the like may be used to guide external light 118a and the like and irradiate the positive electrode 107 and auxiliary electrode 106 with the light.

[0114] 13 is a cross-sectional view and an explanatory diagram of the positive electrode 107 in the embodiment of the present invention. A cavity 506 is formed inside the positive electrode 107 or the auxiliary electrode 106.

[0115] Note that cavity 506 may have any shape or configuration as long as it has an area that can input or guide light 118. For example, cavity 506 may have a branched space. Cavity 506 or its outer surface may be filled with or be provided with a light diffusing material such as opal glass or titanium oxide, so that incident light 118 is diffusely reflected inside positive electrode 107, etc.

[0116] The means for guiding the light 118 to the cavity 506 is not limited to the optical fiber 503. For example, a mirror, a prism, etc. may be used. Furthermore, a main beam with narrow directivity may be condensed by a lens or the like.

[0117] The positive electrode 107 and the like are not limited to being plate-shaped or cylindrical. As an embodiment, they may be formed in a foil shape. Furthermore, they may be formed or configured in a sponge shape, a mesh shape, or by laminating multiple foils so that the light 118 is irradiated to the fine details of the positive electrode 107 and the like.

[0118] Current flows in and out of the terminal electrode 202a, and the positive electrode 107 etc. are oxidized as hydrogen is produced. By irradiating the positive electrode 107 etc. with light 118 from the inside, the positive electrode 107 etc. can be reduced or changed. The embodiment of FIG. 13 has a configuration in which light is guided into the cavity 506 inside the positive electrode 107, auxiliary electrode 106, etc., and the positive electrode 107, etc. is reduced or changed. FIG. 14 is an explanatory diagram of the configuration of the positive electrode 107, auxiliary electrode 106, etc. in the hydrogen generating device 201 of the present invention.

[0119] The positive electrode 107 etc. is configured or arranged in a mesh, lattice, line, foil or other shape around the light generating device 117 (light generating section 117) or in contact with the light generating device 117 (light generating section 117).

[0120] A light guide plate is exemplified as the light generating unit 117. Light 118 is guided through the light guide plate 302, and the guided light 118 is irradiated onto materials such as the positive electrode 107. The positive electrode 107 and the like are reduced or the like by the light irradiation.

[0121] 13 and 14 show a configuration in which a light generating means (light emitting means) is formed or disposed inside a material such as the positive electrode 107. The present invention is not limited to this, and for example, as shown in Fig. 15, the positive electrode 107 etc. may be disposed inside, and the surrounding area may be formed or disposed with a light diffusing material 509 made of a porous material such as a sponge and having a light guiding function or light diffusing performance.

[0122] The light diffusing material 509 is formed or arranged in a state in which a space 506 is maintained around the positive electrode 107, etc., or in close contact with the positive electrode 107, etc. The light diffusing material 509 has the ability to allow the electrolyte solution 104 (electrolyte solution 105) to penetrate or permeate therethrough, and can move sodium ions, etc. The positive electrode 107 and the like have a hydrogen production function via the electrolytic solution 104 (electrolytic solution 105) that has penetrated into the light diffusing material 509. Light 118 generated by light generator 117 is guided through light diffusing material 509, and the guided light 118 is irradiated onto positive electrode 107 and the like.

[0123] The light-generating portion of the light-generating device 117 and the positive electrode 107 may be bonded together, placed back to back, or placed face to face. Alternatively, a plurality of light-generating bodies and positive electrodes 107 may be stacked. Alternatively, a plurality of light-generating bodies and auxiliary electrodes 106 may be stacked. The positive electrode 107 can be reduced or changed by photogeneration. The auxiliary electrode 106 can be reduced or changed by photogeneration.

[0124] The light generating portion of the light generating device 117 and the auxiliary electrode 106 may be bonded together or may be placed back to back. The auxiliary electrode 106 can be reduced by light generation.

[0125] The light generating device 117 is controlled to be in a light generating (on) or non-light generating (off) state by a light generating control circuit 122. The light 118 generated by the light generating device 117 is configured to be irradiated onto the positive electrode 107. The light generating control circuit 122 is controlled by the control circuit 101.

[0126] It is also possible to arrange or configure a generator such as an LED or laser light that generates visible light, ultraviolet light, etc., outside or inside the container 102, and irradiate the light generated by these onto the material of the positive electrode 107, etc. The above matters also apply to Fig. 1 etc. In Fig. 1, light 118 from a light generator 117 etc. is irradiated onto the positive electrode 107.

[0127] FIG. 1 is a diagram and an explanatory diagram of a hydrogen production device according to another embodiment of the present invention. In addition to the components shown in FIG. 8, FIG. 1 includes an auxiliary electrode 106 and a control circuit for the auxiliary electrode 106. The auxiliary electrode 106 has the function of reducing or changing the positive electrode 107. When reducing or changing the positive electrode 107, the switch circuit 115a is turned off (open). The switch circuit 116 is turned on (closed). When a voltage (current) is applied to the positive electrode 107 and the negative electrode from the variable DC power supply 112a, hydrogen is generated at the negative electrode .

[0128] An electrode voltage control circuit 114b is connected between the auxiliary electrode 106 and the positive electrode 107. A switch circuit 116b, a switch circuit 116a, and a variable DC power supply 112 are arranged in the electrode voltage control circuit 114b.

[0129] Because the potential of the reaction between the positive electrode 107 and the auxiliary electrode 106 is positive, the reaction proceeds spontaneously, similar to the discharge of a battery. Therefore, basically, the variable DC power supply 112b is not required. All that is required is to turn on (close) the switch circuit 116b. In the hydrogen production process, the switch circuit 116 is turned off (open) and the switch circuit 115a is turned on (closed). The positive electrode 107 and the auxiliary electrode are separated by a cation exchange membrane, and when the switch circuit 116b is turned on (closed), this corresponds to discharging the battery, and the reaction proceeds.

[0130] The reaction gradually slows down, so when the reaction progresses beyond a certain level, switch circuit 116b is turned off (open) and switch circuit 116a is turned on to apply a voltage between positive electrode 107 and auxiliary electrode 106, thereby promoting the reaction. A salt bridge (electrolyte bridge) 121 may be used between the positive electrode 107 and the auxiliary electrode 106 instead of using the separator 119b.

[0131] The salt bridge 121 is preferably an inverted U-shaped or H-shaped glass tube filled with salt solution to connect the two electrode system solutions. To prevent the electrode system solutions from mixing, the tubes are plugged with wooden wicks or cotton at both ends, or the inside of the salt bridge is solidified with agar or gelatin.

[0132] 1, the electrode voltage control circuit 114 is formed with a variable DC power supply 112, a switch circuit 116, and a switch circuit 115. Note that the electrode voltage control circuit 114 is not limited to controlling only the voltage between the terminals, but can also control the magnitude and direction of the current flowing between the terminals.

[0133] The electrode voltage control circuit 114 electrically connects the terminal electrodes 202 (terminal electrode 202a, terminal electrode 202b, terminal electrode 202c) of the hydrogen production device 201 to an applied current (voltage) control device 401, and controls the voltage applied to each terminal electrode 202 or the on / off between the terminal electrodes 202.

[0134] The light generating device 117 is controlled to be in a light generating (on) or non-light generating (off) state by a light generation control circuit 122. The light 118 generated by the light generating device 117 is configured to be irradiated onto the positive electrode 107 and the like.

[0135] As hydrogen production continues, the Na + The concentration increases. + For the purpose of adjusting the concentration, the electrolyte circulator 111 takes in the electrolyte 104a from the positive electrode 107 and takes out the electrolyte 104b from the negative electrode . In order to reduce unevenness in the ion distribution in the electrolytes 105 and 104, the stirring fan 103 is rotated to stir the electrolytes. A cation exchange membrane is placed or disposed between the auxiliary electrode 106 and the positive electrode 107 as a separator 119b.

[0136] There are no particular restrictions on the material or configuration of the negative electrode 108. Any material that is not susceptible to corrosion and has been developed for electrolytic reduction can be used. Examples include graphite, carbon materials, platinum, and nickel. Mild steel can be used as is, or it can be stabilized by nickel plating or sulfurized to increase activity. For both electrodes, the surface is roughened to activate it, and it is preferable to use an expanded metal or the like as the substrate to facilitate gas escape.

[0137] The graphene / nickel molybdenum electrode with nano-sized holes has a higher reduction current value than platinum / carbon (10 wt% platinum) and has excellent hydrogen production capacity. Protecting the base metal surface with graphene with nano-sized holes can achieve both long life and performance as an electrode.

[0138] When Prussian blue oxidizes, it can dissolve in the electrolyte, so it must be kept in the electrode. Using sodium phosphate in the electrolyte prevents the active material from dissolving.

[0139] Prussian blue is a deep blue complex; iron(III) hexacyanidoferrate(II), iron(III) ferrocyanide, ferric ferrocyanide, and iron blue are other names for Prussian blue. In reality, it often contains water of crystallization and some of the iron ions are substituted, and these can also be used.

[0140] The auxiliary electrode 106 is made of Na4[Fe II (ox)3] is mixed with graphite, and this is coated or spread on the collector electrode, or sandwiched around the collector electrode, or mixed in. The material of the collector electrode is not specified.

[0141] The collecting electrode may be formed or configured from stainless steel, titanium, copper, zinc, nickel, aluminum, copper, stainless steel, sintered alloy, wire mesh, foam metal, ceramic, etc. Furthermore, platinum, gold, silver, tin, zinc, tungsten, titanium, copper, nickel, or an alloy combining these may be formed or disposed on the surface.

[0142] The separator 119 is a cation exchange membrane. The cation exchange membrane is negatively charged due to the anionic groups fixed to the membrane. Therefore, anions are repelled and cannot pass through, and only cations can pass through.

[0143] For example, there is the ion exchange membrane "Selemion" developed and manufactured by the AGC Group. Another example is a fluorine-based cation exchange membrane made from sulfonic acid polymers.

[0144] The electrolyte 104 for the negative electrode 108 and the positive electrode 107 is exemplified by an aqueous solution of sodium carbonate or sodium bicarbonate. It is important to maintain the solution at a weak alkaline state. Sodium phosphate is also an example.

[0145] The electrolyte of the auxiliary electrode 106 is exemplified by sodium oxalate, Na2ox. The use of sodium oxalate has the effect of forming a complex when an oxalic acid complex is decomposed.

[0146] Terminal electrode 202b is connected to negative electrode 108, and terminal electrode 202a is connected to positive electrode 107. Variable DC power supply 112a is connected between terminal electrode 202b and terminal electrode 202a. Variable DC power supply 112a is configured to be able to generate any voltage in the range of 0V to 10V.

[0147] The variable DC power supply 112a is also configured to be able to control the output current to a constant current. It is also configured to be able to vary the applied current or applied voltage in response to the elapsed time or the amount of hydrogen generated. The variation of the voltage or current is controlled by a control circuit 101.

[0148] When the switch circuit 115a is turned on, a current flows between the negative electrode 108 and the positive electrode 107, and hydrogen is generated. As the current flows between the negative electrode 108 and the positive electrode 107, sodium ions permeate the cation exchange membrane 119a. Sodium ions Na + The metal complexes are anions and remain at their respective electrodes.

[0149] When hydrogen is generated at the negative electrode, a difference in the concentration of sodium ions occurs near the negative electrode and the positive electrode (hexacyanoiron(II) complex). This causes a change in the acid concentration, so it is necessary to mix it from time to time. If there is no separator between the negative and positive electrodes, simply stirring is sufficient.

[0150] In strongly acidic aqueous solutions, the hexacyanoiron(II) complex may decompose, so the pH of the solution must be adjusted. One way to do this is with a buffer solution consisting of a combination of sodium dihydrogen phosphate and phosphoric acid. for example, Sodium dihydrogen phosphate dihydrate (7.8 g) Phosphoric acid (85%) (3.4 mL)

[0151] Dissolving both in water to a total volume of 1 L produces a buffer solution with a pH of 2.1. Varying the ratio of sodium dihydrogen phosphate dihydrate to phosphoric acid (85%) produces buffer solutions with various pH values. Other weak acids, such as citric acid and tartaric acid, can also be used to create weakly acidic water, but a combination of inorganic acids and salts is preferred.

[0152] In order to keep the amount of hydrogen generated constant, the control circuit 101 varies and controls the output voltage and output current of the variable power supply circuit (variable DC power supply, variable voltage power supply) 112a.

[0153] Although the variable power supply circuit (variable DC power supply, variable voltage power supply) 112 is described as "variable," it is not limited to being variable. For example, it may be a fixed power supply 112 that outputs a constant voltage or current. It may be provided with a plurality of fixed power supplies 112, and one of the plurality of fixed power supplies 112 may be selected by a switch circuit (not shown) to be used as the applied voltage.

[0154] As hydrogen production continues, the Na + The concentration increases. + For the purpose of adjusting the concentration, an electrolyte circulator 111 takes in electrolyte 104a from the positive electrode 107 and takes out electrolyte 104b from the negative electrode .

[0155] In order to reduce unevenness in the ion distribution in the electrolytes 105 and 104, the electrolytes are stirred by rotating the stirring fan 103. Instead of the stirring fan 103, a pump or the like that generates a water current may be used.

[0156] Hydrogen (H2) generated at the negative electrode 108 is collected by a gas collector 109 and transferred to a gas reservoir 120 via a pipe 110. A dryer 410 (hydrogen gas dryer) is disposed at the input of the gas reservoir 120.

[0157] A hydrogen gas dryer is a device that removes moisture from hydrogen gas. An example of an adsorption type is one that dehumidifies by having an adsorbent absorb the moisture. Some types use a heater to regenerate the adsorbent, while others do not. For the heating type, the main circuit is made up of a regeneration tower heater replacement valve, a regeneration path valve, etc., to match the heater.

[0158] The gas collector 109 and the pipe 110 are subjected to a process called baking. Baking is performed to release absorbed hydrogen to prevent brittle fracture. The treatment method varies depending on the metal material, processing performed on the metal, and the type of metal, but heating is performed at 190°C to 220°C for 2 to 24 hours. It is also preferable to coat the inner surfaces (such as the portions that come into contact with hydrogen) of the gas collector 109 and the pipe 110 with glass or an inorganic material.

[0159] [Fe III (ox)3] 3- is highly sensitive to visible light 118 and readily reacts with [Fe III (ox)3] 4- The light is not limited to visible light, but may be ultraviolet light or near ultraviolet light. Ultraviolet light is more active.

[0160] By introducing sunlight through glass fiber or using a light generating device such as a backlight for LCD, [Fe III (ox)3] 3- is reduced to [Fe II (ox)3]4- Since sunlight is infinite and there are no energy costs, costs can be reduced.

[0161] Naturally, [Fe III (ox)3] 3- Electrically, [Fe II (ox)3] 4- Since the redox potential is 0.02V, the power consumption is small.

[0162] [Fe III (CN)6] 3- Although photoreduction is also possible with the auxiliary electrode 106, [Fe III (ox)3] 3- Photoreduction of [Fe is more reliable. III (ox)3] 3- The reduction reaction is accelerated by adding heat.

[0163] An electrode voltage control circuit 114 is connected between the auxiliary electrode 106 and the positive electrode 107. Within the electrode voltage control circuit 114, a switch circuit 116b, a switch circuit 116a, and a variable DC power supply 112 are arranged.

[0164] Because the potential of the reaction between the positive electrode 107 and the auxiliary electrode 106 is positive, the reaction proceeds spontaneously, similar to the discharge of a battery. The positive electrode 107 and the auxiliary electrode are separated by a cation exchange membrane, and when the switch circuit 116b is turned on (closed), this corresponds to the discharge of a battery, and the reaction proceeds.

[0165] Since the reaction gradually decreases, it is also preferable to accelerate the reaction when the reaction progresses beyond a certain level by turning off (opening) switch circuit 116b and turning on switch circuit 116a to apply a voltage between positive electrode 107 and auxiliary electrode 106. The voltage may be continuously changed using a variac (not shown).

[0166] Separator 119b may not be used between positive electrode 107 and auxiliary electrode 106, and salt bridge (electrolyte bridge) 121 may be used. To connect the two electrode system solutions, salt bridge 121 is preferably an inverted U-shaped or H-shaped glass tube filled with salt solution. To prevent the electrode system solutions from mixing, wooden or cotton plugs are placed on both ends of the tube, and the inside of salt bridge 121 is solidified with agar or gelatin to connect them.

[0167] A concentrated solution of a salt in which the mobilities of anion and cation are as equal as possible is used as the salt solution in order to reduce the liquid junction potential difference and the increase in circuit resistance due to the salt bridge 121. Examples include a concentrated solution of potassium chloride, ammonium nitrate, and potassium nitrate.

[0168] The control circuit 101 controls the light generation control circuit 122, which supplies power to the light generating device 117 and controls whether the light generating device 117 generates light 118 or not (turns off).

[0169] When the auxiliary electrode 106 is to be reduced, the switch circuit 115a is turned off to stop the generation of hydrogen. That is, the switch circuit 115a is turned off, the switch is turned on, and the light generator 117 is caused to generate light 118.

[0170] 3 is an explanatory diagram of a hydrogen generator 201 according to the present invention. As shown in FIG. 3(a), the auxiliary electrode 106 has a mesh-like structure or a plate structure with many fine holes. By forming the auxiliary electrode 106 in a mesh-like structure, the contact area between the electrolyte 105 and the auxiliary electrode 106 increases, improving efficiency.

[0171] 3(a) can also be applied to the positive electrode 107 and the negative electrode 108. Because a large number of minute holes are formed, light 118 can pass through each electrode and irradiate the other electrodes, as shown in FIGS.

[0172] 1, by configuring the auxiliary electrode 106 as shown in FIG. 3(a), light 118 can pass through the mesh-like openings and the numerous hole openings of the auxiliary electrode 106. Therefore, light 118 from the light-generating device 117 can pass through the auxiliary electrode and irradiate the positive electrode 107.

[0173] FIG. 3(a) is an explanatory diagram of the light generating device 117 of the hydrogen generator 201. The auxiliary electrodes 106 in FIG. 3(a) are arranged in a stacked manner with a certain interval between them. The electrodes are electrically connected so that the same voltage can be applied or the electrodes can be maintained at the same potential. The auxiliary electrodes 106 may also be configured so that independent voltages can be applied to each of them. By adopting the above configuration and method, efficiency is improved.

[0174] The formation of the mesh-like openings and openings with many holes in Fig. 3 also applies to the positive electrode 107 and the negative electrode 108. This increases the area in contact with the electrolyte 104, etc., and improves the efficiency of hydrogen production. It goes without saying that the electrode is not limited to those with mesh-like openings or openings with many holes, and may be one having a spongy or sponge-like porous structure. In the examples of FIGS. 1 and 8, reduction is mainly performed by light irradiation, but the present invention is not limited to this. FIG. 16 shows a method in which the positive electrode 107 is removed from the electrolyte 104 in the container 102a and moved into the container 102b, where the positive electrode 107 is reduced, changed, or the like.

[0175] After hydrogen production, the terminal electrode 202a of the positive electrode 107 is removed from the electrode voltage control circuit 114b. The removal may be performed manually, or the positive electrode 107 may be mechanically and automatically removed from the terminal electrode 202a and moved to the electrolyte 104a in the container 102b.

[0176] The positive electrode 107 is removed from the electrolyte 104 in the container 102a and moved to the container 102b. The terminal electrode 202a of the positive electrode 107 is connected to the electrode voltage control circuit 114b.

[0177] Switch circuits 116a and 116b are formed or disposed within electrode voltage control circuit 114b. Switch circuits 115 and 116 are configured with mechanical switches, analog switches, MOS transistors, or the like.

[0178] A variable DC power supply 112b is connected to the switch circuit 116a as needed. The variable DC power supply 112b can vary the magnitude, direction or polarity of a DC voltage or DC current.

[0179] An ammeter 512b is disposed in the path through which the current flows. The ammeter 512b measures the current flowing in the path, and the measured current value and current change are sent to the control circuit 101. The control circuit 101 controls the on (closed) and off (open) of the switch circuits 116a and 116b based on the current value, etc., and changes or controls the output value of the variable DC power supply 112.

[0180] The positive electrode 107 of the container 102b is connected to an electrode voltage control circuit 114b. Current flows when the switch circuit 116a is open and the switch circuit 116b is closed.

[0181] A potential difference occurs between the positive electrode 107 and the auxiliary electrode 106. When the switch circuit 116b is turned on (closed) to electrically connect the positive electrode 107 and the auxiliary electrode 106, discharge occurs, and the positive electrode 107 is reduced or changed.

[0182] As the reduction or change of the positive electrode 107 progresses, the flowing current decreases. Therefore, as necessary, the switch circuit 116b is turned off (open) and the switch circuit 116a is turned on (closed). By turning on (closing) the switch circuit 116a, the variable DC power supply 112b is inserted into the current path. By increasing the potential difference with the variable DC power supply 112b, the reduction time or change time becomes shorter. Needless to say, the above can also be applied to the auxiliary electrode 106.

[0183] 16, the positive electrode 107 is heated or warmed directly by a heating means such as a heater 510, or indirectly via the electrolyte 104, etc. Heating or warming promotes or accelerates the reduction or change of the positive electrode 107.

[0184] 1, 8, etc., a light-generating device 117 may be disposed so that light is irradiated onto the positive electrode 107, and the light 118 generated by the light-generating device 117 may be irradiated onto the positive electrode 107. Needless to say, the above matters can also be applied to the auxiliary electrode 106.

[0185] 16 shows a configuration or method in which the positive electrode 107 is removed and changed (restored), such as by removing the positive electrode 107 from the container 102a and moving the positive electrode 107 to the container 102b. However, the present invention is not limited to this.

[0186] FIG. 17 is a diagram and an explanatory view of the configuration of a hydrogen production device of the present invention, which continuously produces hydrogen by the positive electrode 107 in the container 102 and reduces or changes the positive electrode 107 without removing it. In FIG. 17, a plurality of positive electrodes 107 (positive electrodes 107 a and 107 b ) are connected to or disposed on the rotating shaft of a motor 511 .

[0187] At least one of the plurality of positive electrodes 107 is disposed or held in the electrolyte 104a of the container 102. At least one of the plurality of positive electrodes 107 is disposed or held outside the electrolyte 104a of the container 102.

[0188] The motor 511 rotates, and the state in which the positive electrode 107a is in the electrolyte 104a and the positive electrode 107b is outside the electrolyte 104a and the state in which the positive electrode 107b is in the electrolyte 104a and the positive electrode 107a is outside the electrolyte 104a are continuously or intermittently performed.

[0189] The following description will be given taking the state of Fig. 17 as an example. The positive electrode 107a in the electrolyte 104a is connected to an electrode voltage control circuit 114a, and by closing the switch circuit 115a, a potential is applied between the negative electrode 108 and the positive electrode 107. The state of hydrogen production (hydrogen generation) is determined by the current value measured by the gas flow meter 411 or the ammeter 512a.

[0190] The positive electrode 107b is removed from the electrolyte 104a, and light 118 from the light generating means 117 is irradiated onto the positive electrode 107b. Alternatively, light 118 from sunlight is irradiated onto the positive electrode 107b. When irradiated with light, the positive electrode 107b is restored, reduced, or changed. Therefore, the hydrogen production (hydrogen generation) state by the positive electrode 107a and the restoration, reduction or change state of the positive electrode 107b proceed simultaneously. As the positive electrode 107 is oxidized, the amount of hydrogen measured by the gas flow meter 411 decreases, and the current flowing through the ammeter 512a also decreases.

[0191] When the amount of hydrogen generated within a unit time falls below a predetermined value, that is, when the current flowing through ammeter 512a falls below a predetermined value, the rotating shaft of motor 511 rotates, and the position of positive electrode 107a in Figure 17 becomes the position of positive electrode 107b, and the position of positive electrode 107b becomes the position of positive electrode 107a.

[0192] At least one positive electrode generates hydrogen by being placed or held in the electrolyte 104a of the container 102. At least one positive electrode 107 is placed or held outside the electrolyte 104a of the container 102 and is irradiated with light 118 to be reduced, restored, or changed.

[0193] The control circuit 101 controls the light generation control circuit 122 and the motor 511. The control is performed based on at least one of the amount of hydrogen produced by the gas flow meter 411 and the current value of the ammeter 512.

[0194] In the hydrogen production device of the present invention, a plurality of positive electrodes 107 may be prepared, and the positive electrode 107 may be replaced after the reaction. The replaced positive electrode 107 is reduced and installed or placed again as the positive electrode 107. As shown in FIG. 16, by configuring the positive electrode 107 to be replaceable, the positive electrode 107 can be reused, thereby achieving cost reduction.

[0195] Furthermore, as shown in FIG. 17, by configuring the device so that hydrogen production by the positive electrode 107 and reduction or restoration of the positive electrode 107 can be carried out continuously, space saving of the device and continuous hydrogen production can be achieved. It goes without saying that the above also applies to the auxiliary electrode 106.

[0196] Fig. 6 is an explanatory diagram mainly illustrating the negative electrode 108 and the positive electrode 107 in Fig. 1. As shown in Fig. 6, the positive electrode 107 and the negative electrode 108 are each made up of a plurality of electrodes. In FIG. 6, for ease of illustration, there are four positive electrodes 107 and four negative electrodes 108, but this is not limitative.

[0197] Negative electrode 108 is connected to switch circuit 115a2. Negative electrode 108a is connected to terminal a of switch circuit 115a2, and negative electrode 108b is connected to terminal b of switch circuit 115a2. Positive electrode 107 is connected to switch circuit 115a1. Positive electrode 107a is connected to terminal a of switch circuit 115a1, and positive electrode 107b is connected to terminal b of switch circuit 115a2.

[0198] Variable DC power supply 112a is connected to terminal c of switch circuit 115a1 and terminal c of switch circuit 115a2, and a voltage is applied between positive electrode 107 and negative electrode .

[0199] 6(a) and 6(b) are performed alternately. In Fig. 6(a), the switch circuit 115a (switch circuit 115a1, switch circuit 115a2) is connected to the a terminal, and a DC voltage from the variable DC power supply 112a is applied between the positive electrode 107a and the negative electrode 108a.

[0200] The negative electrode 108a reduces water (or hydrogen ions) to generate hydrogen (H2). In one embodiment of the present invention, a complex of iron (II) and iron (III) is used. For example, hexacyanoiron complex is exemplified. [Fe II (CN)6] 4- This reaction is reversible and occurs rapidly. [Fe II (CN)6] 4- → [Fe III (CN)6] 3- + e - E0= -0.36V (2)

[0201] The positive electrode 107a [Fe III (CN)6] 3- As this progresses, the generation of hydrogen at the negative electrode 108a decreases or stops. III (CN)6] 3- [Fe II (CN)6] 4- It needs to be returned to.

[0202] [Fe III (CN)6] 3- [Fe II (CN)6] 4- The positive electrode 107a is removed from the electrolyte 104a to return the reduced [Fe II (CN)6] 4- The period during which the positive electrode 107a is attached is the same as that shown in FIG. The operation of removing the positive electrode 107a from the electrolyte 104a and the operation of re-inserting the positive electrode 107a into the electrolyte 104a and attaching it thereto are carried out using a mechanical device.

[0203] The positive electrode 107a is removed from the electrolyte 104a and irradiated with light such as sunlight to detect [Fe III (CN)6] 3- [Fe II (CN)6] 4- To change or reduce something into something. It goes without saying that the above matters can also be applied to the embodiments of the present invention such as those shown in FIG.

[0204] In FIG. 6(b), the switch circuit 115a (switch circuit 115a1, switch circuit 115a2) is connected to the b terminal, and a DC voltage from the variable DC power supply 112a is applied between the positive electrode 107b and the negative electrode 108b.

[0205] The negative electrode 108b reduces water (or hydrogen ions) to generate hydrogen (H2). III (CN)6] 3- As this progresses, the generation of hydrogen at the negative electrode 108b decreases or stops. III (CN)6] 3- [Fe II (CN)6] 4- It needs to be returned to.

[0206] [Fe III (CN)6] 3- [Fe II (CN)6] 4- The positive electrode 107b is removed from the electrolyte 104a to return the reduced [Fe II (CN)6] 4- is attached to the position of the positive electrode 107b. The period during which the positive electrode 107b is attached is carried out as shown in FIG. 6(a). By alternately repeating the steps of FIG. 6(a) and FIG. 6(b) in this manner, hydrogen can be produced continuously. In FIG. 6, the removed positive electrode 107 is reduced by the method described with reference to FIGS. FIG. 7 is an explanatory diagram mainly illustrating the auxiliary electrode 106 and the positive electrode 107 in FIGS.

[0207] As shown in Fig. 7, the positive electrode 107 and the auxiliary electrode 106 are each composed of a plurality of electrodes. For ease of illustration, Fig. 7 shows four positive electrodes 107 and four auxiliary electrodes 106, but this is not limitative.

[0208] Auxiliary electrode 106 is connected to switch circuit 116a1. Auxiliary electrode 106a is connected to terminal a of switch circuit 116a1, and auxiliary electrode 106b is connected to terminal b of switch circuit 116a1.

[0209] Positive electrode 107 is connected to switch circuit 116a2. Positive electrode 107a is connected to terminal a of switch circuit 116a1, and positive electrode 107b is connected to terminal b of switch circuit 116a2.

[0210] A variable DC power supply 112b is connected to the terminal c of the switch circuit 116a1 and the terminal c of the switch circuit 116a2 as required, and a voltage is applied between the positive electrode 107 to be reduced or changed and the auxiliary electrode .

[0211] Basically, a potential difference occurs between the positive electrode 107 and the auxiliary electrode 106, and therefore, when the positive electrode 107 and the auxiliary electrode 106 are electrically connected, discharge occurs, and the positive electrode 107 is reduced or changed. By increasing the potential difference using the variable DC power supply 112b, the reduction time or change time becomes shorter.

[0212] When positive electrode 107a to be reduced is attached, a voltage (current) from variable DC power supply 112b is applied between terminal a of switch circuit 116a2 and terminal a of switch circuit 116a1, and positive electrode 107a is reduced.

[0213] When positive electrode 107b to be reduced is attached, a voltage (current) from variable DC power supply 112b is applied between terminal b of switch circuit 116a2 and terminal ba of switch circuit 116a1, and positive electrode 107b is reduced. Between the positive electrode 107 and the auxiliary electrode 106, [Fe III (CN)6]3- + [Fe II (ox)3] 4- → [Fe II (CN)6] 4- + [Fe III (ox)3] 3- E0= +0.34V (6) Reaction (6) is an exothermic reaction, which occurs spontaneously and releases energy. [Fe III (ox)3] 3- may be electrically reduced. [Fe II (ox)3] 4- → [Fe III (ox)3] 3- + e- E0= -0.02V (5) The voltage is close to zero and the power consumption is very low. III (CN)6] 3- This can be reduced using capacitor technology. The positive electrode 107 and the auxiliary electrode 106 are separated by a separator 119b, and when a voltage (current) is applied, this corresponds to discharging a battery, and a reaction proceeds.

[0214] [Fe III (CN)6] 3- Although photoreduction is also possible with the auxiliary electrode 106, [Fe III (ox)3] 3- The photoreduction of [Fe III (ox)3] 3- The reduction reaction will proceed even if heat is applied. Therefore, it is preferable to heat the reaction mixture during the conversion. The reduced positive electrode 107a is removed and attached to the position of the positive electrode 107a shown in FIG.

[0215] When positive electrode 107b to be reduced or changed is attached, a voltage (current) from variable DC power supply 112b is applied between terminal b of switch circuit 116a2 and terminal a of switch circuit 116a1, and positive electrode 107b is reduced, etc. Positive electrode 107b that has been reduced, etc. is taken out and attached at the position of positive electrode 107b shown in FIG.

[0216] By applying a voltage and passing a current between the positive electrode 107 as the negative electrode and the auxiliary electrode 106 as the positive electrode, trivalent iron has a potential 0.36 V higher than divalent iron, so even at a low voltage, a current flows, the trivalent iron is reduced to divalent iron, and the positive electrode 107 is regenerated.

[0217] The power consumption required to regenerate the positive electrode 107 is extremely small because the applied voltage is low. The method of connecting the positive electrode 107 to the negative electrode of the capacitor generates an output during regeneration, but it is time-consuming and consumes power when charging the capacitor.

[0218] As described above, the auxiliary electrode 106 and the positive electrode 107 that constitute the capacitor are connected, and a variable DC power supply 112b is connected between the auxiliary electrode 106 and the positive electrode 107 to apply a voltage. III (CN)6] 3- [Fe II (CN)6] 4- To reduce (change) to.

[0219] The reduced positive electrode 107 is taken out. The auxiliary electrode 106 and the positive electrode 107 that constitute the capacitor are connected, and a variable DC power supply 112b is connected between the auxiliary electrode 106 and the positive electrode 107 to apply a voltage. By applying the voltage, [Fe III (CN)6] 3- [Fe II (CN)6] 4- Reduce to.

[0220] The potential is +0.36 V, so the reaction proceeds spontaneously. The load on the capacitor is small, but it still needs capacity to reduce iron(III). The electrochemical method using a capacitor is more efficient than photoreduction using an auxiliary electrode.

[0221] It goes without saying that the electrochemical method using a capacitor may be combined with the photoreduction method. The electrochemical method of Figures 6 and 7 may be combined with the photoreduction method of irradiating light 118 described with reference to Figures 1 and 8. It also goes without saying that it may be combined with other embodiments of the present invention such as those shown in Figures 16 and 17.

[0222] 6 and 7, the positive electrodes 107a and 107b are alternately replaced to perform reduction, etc. However, this is not limiting. For example, the positive electrodes 107 may be removed one by one and reduction, etc. may be performed at appropriate times. Furthermore, as described in FIG. 1, reduction, etc. may be performed by irradiating with light 118, or light irradiation and voltage application may be performed simultaneously.

[0223] In the above embodiment, variable DC power supply 112b is connected, but a load 505 may also be connected as shown in Fig. 11. A capacitor is formed with positive electrode 107 and auxiliary electrode 106 as electrodes, and by closing (turning on) switch circuit 116, a current flows through load 505, causing the load to operate.

[0224] Examples of the load 505 include a motor having an inverter circuit, a communication device, a light source, a rechargeable battery, etc. It goes without saying that the load 505 may be a resistance element, a resistor, or a discharge element.

[0225] The charge on the positive electrode 107 can be discharged by short-circuiting or connecting the terminal electrode 202a of the positive electrode 107 to ground or to another potential object without providing or connecting the auxiliary electrode 106. Therefore, the positive electrode 107 can be reduced, oxidized, restored, or subjected to a reversible reaction.

[0226] An electrode voltage control circuit 114 is connected between the auxiliary electrode 106 and the positive electrode 107. Within the electrode voltage control circuit 114, a switch circuit 116b, a switch circuit 116a, and a variable DC power supply 112 are arranged.

[0227] Because the potential of the reaction between the positive electrode 107 and the auxiliary electrode 106 is positive, turning on (closing) the switch circuit 116b causes the reaction to proceed spontaneously, similar to the discharge of a battery. The positive electrode 107 and the auxiliary electrode are separated by a cation exchange membrane, and turning on (closing) the switch circuit 116b corresponds to the discharge of a battery, and the reaction proceeds.

[0228] Since the reaction gradually decreases, when the reaction progresses beyond a certain level, it is preferable to turn off (open) switch circuit 116b and turn on switch circuit 116a to apply a voltage between positive electrode 107 and auxiliary electrode 106, thereby promoting or accelerating the reaction. It goes without saying that a salt bridge (electrolyte bridge) 121 may be used between the positive electrode 107 and the auxiliary electrode 106 instead of using the separator 119b.

[0229] The material of the positive electrode 107 is reduced or changed in the container 102b. After reduction, the material is transferred into the container 102a, and hydrogen can be produced by connecting the electrode voltage control circuit 114a to the terminal electrode 202a.

[0230] It goes without saying that it is possible to combine the configurations of the embodiments of the present invention described in the specification and drawings such as Figures 1, 8, and 16. The above matters are also applicable to other embodiments of the present invention.

[0231] 12, the auxiliary electrode 106 and the positive electrode 107 may be arranged in a dispersed or divided or discrete manner. The auxiliary electrode 106 is arranged or configured so that it does not or hardly blocks light 118 from the light generating device 117.

[0232] For example, light 118 generated by light generator 117 passes between auxiliary electrodes 106 and is irradiated onto positive electrode 107. When irradiated with light, positive electrode 107 is changed, reduced, restored, or reversibly changed. The change time of the positive electrode 107 can be shortened by heating or warming it with infrared rays or the like. As shown in FIG. 16, the positive electrode 107 is heated or warmed directly by a heating means such as a heater 510 or indirectly via the electrolytic solution 104 or the like.

[0233] A light generating device 117a may be disposed on the opposite surface of the positive electrode 107, and light 118b generated by the light generating device 117a may be irradiated onto the positive electrode 107. The positive electrode 107 is irradiated with light from both sides. For example, as shown in FIG. 9, a condenser lens 502 may be used to irradiate sunlight 118a onto the positive electrode 107 in FIG.

[0234] 13, a cavity 506 is formed inside the positive electrode 107, and is formed in a sponge or mesh shape so as to generate a light path to the positive electrode 107. As shown in FIG. 9, backlight 118, optical fiber 503, or the like, guides light 118 into the cavity 506. Light 118 that enters cavity 506 is reflected or absorbed inside the positive electrode 107, reducing or changing the positive electrode 107 material.

[0235] Light can be transmitted by forming the material that makes up the positive electrode 107 into a thin film or foil. By forming or configuring the material into a thin film or foil, light irradiated onto the positive electrode 107 can travel to the inside of the positive electrode.

[0236] In the above examples, the positive electrode 107 is reduced or restored by light irradiation after contributing to hydrogen production, but the present invention is not limited to this. For example, it goes without saying that the positive electrode 107 may be reduced or restored by light irradiation simultaneously with hydrogen production. 4 and 5 are explanatory and structural diagrams of the hydrogen production device of the present invention, and explanatory diagrams of the hydrogen production method of the present invention.

[0237] Although one hydrogen generator 201 is shown in FIG. 4, the hydrogen generator of the present invention is configured with a plurality of hydrogen generators 201 arranged in a matrix or block, as shown in FIG. 5.

[0238] 4 shows the configuration having the auxiliary electrode 106 as in the configuration described in Fig. 1 etc., but is not limited to this. It goes without saying that the configuration may not have the auxiliary electrode 106, as described in Fig. 8, Fig. 16 etc. The level detector 409 detects the water level of the electrolyte, and when the water level reaches a predetermined set value or more, it turns on and transmits a water level signal to the control circuit 101.

[0239] The gas flow meter 411 is a device that measures the amount of hydrogen generated. The amount of hydrogen and the change in the amount of hydrogen generated are transmitted to the control circuit 101. If the amount of hydrogen generated or the change in the amount of hydrogen is outside a predetermined range, the control circuit 101 controls the applied current control circuit 401, which controls the voltage (current) value applied between the electrodes, so that the amount of hydrogen generated becomes a predetermined value.

[0240] The hydrogen generated in the hydrogen generator 201 is not stored in the hydrogen generator 201, but is sent to a gas separation tank 408 together with the electrolyte via a pipe 110 or the like. The hydrogen (H2) and the electrolyte are separated in the gas separation tank 408. The separated hydrogen has its dew point adjusted in a dryer 410 (a dryer or the like), is sent to a gas flow meter 411, and is stored in the gas storage device 120.

[0241] The electrolytic solution is sent to a liquid tank 407 via a solenoid valve 405. When the level of the electrolytic solution in the gas separation tank 408 reaches or exceeds a predetermined value, the solenoid valve 405 turns on to send the electrolytic solution to the liquid tank 407. When the water level in the liquid tank 407 reaches or exceeds a predetermined value, the solenoid valve 405 turns off to stop the sending of the electrolytic solution. The solenoid valve 405 is controlled by a control circuit 101.

[0242] The liquid tank 407 is configured so that the electrolyte can be replenished. + The water contains an ion exchange resin or the like to adjust the ion concentration of the water. The electrolyte from the liquid tank 407 is pumped by the pump 403, filtered by the filter 404 to remove impurities other than the electrolyte, and then sent to the hydrogen generator 201. The pump 403 is controlled by the control circuit 101 so that the pressure of the electrolyte in the hydrogen generator 201 is controlled to be within a predetermined range.

[0243] 5 is a diagram showing the configuration of a hydrogen production device of the present invention and an explanatory diagram of a hydrogen production method. The hydrogen production device of the present invention is equipped with multiple hydrogen production units 501. Each hydrogen production unit 501 has multiple hydrogen producers 201, and one or more light generators 117 corresponding to the multiple hydrogen producers 201.

[0244] A light generation control circuit 122 is connected to the light generator 117 and controls the light generation from the light generator 117 (light generation / no light generation, weak light intensity / strong light intensity). The light generator 117 emits the generated light continuously or in pulses. The continuous light intensity or the pulse width and period of the pulses can be set and changed.

[0245] The applied current (voltage) control device 401 supplies a voltage (current) to the terminal electrodes 202 of the multiple hydrogen production devices 201, and also opens / closes the terminal electrodes.

[0246] The hydrogen production units 501 (hydrogen production units 501a to 501n) are each configured so that the hydrogen production operation and the light generation by the light generator 117 can be performed in each hydrogen production unit 501.

[0247] For example, the hydrogen production unit 501a can be controlled or set to be in a hydrogen production (hydrogen generation) state, and the hydrogen production unit 501b can be controlled or set to be in a reduction state by turning on the light generating device 117b.

[0248] Each hydrogen production unit 501 can be independently set to produce or not produce hydrogen. The amount of hydrogen produced can be controlled to a constant value. The amount of hydrogen produced can be easily controlled according to the amount of hydrogen stored in the gas storage device 120.

[0249] The hydrogen generator 201 is composed of three electrodes (positive electrode 107, negative electrode 108, and auxiliary electrode 106) separated by an ion exchange membrane 119. When a voltage (current) is continuously applied from the variable DC power supply 112a to the positive electrode 107 and negative electrode 108 of the hydrogen generator 201, hydrogen is generated. When the auxiliary electrode 106 and the positive electrode 107 are short-circuited, the auxiliary electrode 106 is reduced.

[0250] Hydrogen generators are a safe, convenient alternative to high-pressure hydrogen gas cylinders. They are more cost-effective. Hydrogen has approximately half the viscosity of helium, so using hydrogen as carrier gas increases sample analysis throughput. In the case where an internal hydrogen leak occurs in the hydrogen production device of the present invention, gas production is stopped in the hydrogen production device, and a warning is issued by generating an alarm and a voice alarm.

[0251] If a leak occurs external to the generator or persists for more than 20 minutes, shut down the hydrogen production equipment to prevent accumulation of hydrogen gas in the lab environment or in the equipment being supplied. The present invention will shut down the system if the internal pressure exceeds 120 psi. It also has an external output signal that can be connected to external equipment. As shown in FIG. 1, the applied current (voltage) control device 401 includes a variable DC power supply 112, a switch circuit 116, and a switch circuit 115.

[0252] The terminal electrodes 202 (terminal electrode 202a, terminal electrode 202b, terminal electrode 202c) of the hydrogen production device 201 are electrically connected to the applied current (voltage) control device 401, and the voltage applied to each terminal electrode 202 or the voltage between the terminal electrodes 202 is controlled on and off.

[0253] The light generating device 117 is controlled to be in a light generating (on) or non-light generating (off) state by a light generation control circuit 122. The light 118 generated by the light generating device 117 is configured to be irradiated onto the auxiliary electrode 106.

[0254] The present invention relates to [Fe III (CN)6] 3- To drive the reduction reaction, an auxiliary electrode 106 made of graphite and activated carbon as active materials is joined to a separator 119b. III (CN)6] 3- When a voltage is applied between the negative electrode (positive electrode 107) and the graphite-activated carbon electrode (auxiliary electrode 106), a current flows. When a current flows, [Fe III (CN)6] 3- is reduced and [Fe II (CN)6] 4- Return to. Holes are generated in the graphite-activated carbon electrode (auxiliary electrode 106), but they disappear naturally due to the diffusion of ions, but can be used as energy. The reaction at the positive electrode is [Fe II (CN)6] 4- → [Fe III (CN)6] 3- + e - E0= -0.36V (2) Activate.

[0255] Figure 9 is an explanatory diagram explaining a method of using sunlight. It is preferable to use natural light such as sunlight as a method of reducing power consumption in hydrogen production. By using sunlight, it is possible to reduce power consumption in hydrogen production.

[0256] Sunlight 118a is concentrated by a concentrating lens 502 and guided by an optical fiber 503 onto the positive electrode 107. The light irradiation activates the complexes on the positive electrode 107, increasing the reaction rate. This method reduces power consumption and increases the rate of hydrogen production. The direction of the concentrating lens 502 is configured so that its angle can be adjusted toward the sun.

[0257] As shown in FIGS. 8, 10, 11, 12, etc., it goes without saying that the light generating device 117 may be arranged and configured so that the light 118 generated by the light generating device 117 is irradiated onto the positive electrode 107. 8 and 10, the positive electrode 107 may be irradiated with light 118 generated by a light generator 117.

[0258] The control circuit 101 controls the light generation control circuit 122, which supplies power to the light generating device 117 and controls whether the light generating device 117 generates light 118 or not (turns off).

[0259] A light generator 117 is disposed at one end of the container 102, and the light generator 117 generates ultraviolet light 118. The ultraviolet light 118 is generated by an ultraviolet LED, an ultraviolet laser, or the like. Light 118 emitted (emitted) from the light generating device 117 is irradiated onto the positive electrode 107 .

[0260] 2, 10, 19, and 28 are cross-sectional views and explanatory diagrams of the hydrogen generator 201 of the present invention. The container 102 may be any type that is airtight and prevents leakage of the electrolyte 105. Since heat may be generated during charging or discharging, it is preferable to construct the container 102 from ceramic or metal, which have good heat dissipation properties.

[0261] 2 and the like, the stirring fan 103 and the like that are not necessary for the explanation are omitted. It goes without saying that the matters and contents explained in this specification and the drawings can be applied or implemented in FIGS. 2, 10, 19, and 20.

[0262] 2 and other figures, a negative electrode 108, a positive electrode 107, and an auxiliary electrode 106 are arranged inside the container 102. A terminal electrode 202b is connected to the negative electrode 108, and is configured so that it can be connected to a power source for the container 102.

[0263] A terminal electrode 202a is connected to the positive electrode 107, and is configured to be connectable to a power source of the container 102. A terminal electrode 202c is connected to the auxiliary electrode 106, and is configured to be connectable to a power source (such as a variable DC power source 112) arranged outside the container 102.

[0264] One or more hydrogen outlet holes 203 are provided in the container 102. Hydrogen generated at the negative electrode 108 is taken out of the container 102 through the hydrogen outlet holes 203. A gas collector 109 is disposed outside the container 102, and hydrogen collected by the gas collector 109 is collected in a gas reservoir 120 via a pipe 110. The separator 119 is, for example, a cation exchange membrane through which ions move.

[0265] A light generating device 117 is disposed at one end of the container 102. The light generating device 117 may be, for example, a backlight for an LCD or the like. The light generating device 117 is not limited to one that generates light 118.

[0266] The container 102 is provided with an outflow hole 507 through which the electrolytic solution 104 flows out and an inflow hole 508 through which the electrolytic solution 104 flows in. The electrolyte circulator 111 replaces the electrolytic solution 104 via the outflow hole 507 and the inflow hole 508. Replacing the electrolytic solution 104 prevents sodium ions and the like from accumulating, improving the efficiency of hydrogen production. For example, a configuration is exemplified in which sunlight is guided from the outside of the container 102 using a light guide material and introduced into a light guide plate or the like of the light generating device 117.

[0267] 10 shows an embodiment in which a light-transmitting window 504 that transmits visible light, ultraviolet light, laser light, etc. is formed or configured in the container 102. Light 118 generated by the light generator 117 passes through the light-transmitting window 504 and is irradiated onto the auxiliary electrode 106, the positive electrode 107, etc.

[0268] 2, a negative electrode 108, a positive electrode 107, and an auxiliary electrode 106 are arranged inside a container 102. A terminal electrode 202b is connected to the negative electrode 108, and the terminal electrode 202b is extended to the outside of the container 102. A terminal electrode 202a is connected to the positive electrode 107, and the terminal electrode 202a is extended to the outside of the container 102.

[0269] A terminal electrode 202c is connected to the auxiliary electrode 106, and the terminal electrode 202c is drawn out to the outside of the container 102. The container 102 is filled with an electrolyte 104 and an electrolyte 105.

[0270] An electrode voltage control circuit 114 is connected to the terminal electrode 202, and hydrogen is generated by controlling the voltage between the negative electrode 108 and the positive electrode 107. The generated hydrogen is taken out of the container via a hydrogen outlet hole 203. A pipe 110, a gas collector 109, a gas flow meter 411, etc. are attached to the hydrogen outlet hole 203.

[0271] The container 102 is formed with an inlet hole 507 and an outlet hole 508 for the electrolyte 104. The electrolyte circulator 111 injects and discharges the electrolyte 104 through the inlet hole 507 and the outlet hole 508.

[0272] A light-generating device 117 is disposed or configured on at least one surface of the container 102. The light-generating device 117 generates light 118 and irradiates the auxiliary electrode 106 and the positive electrode 107 with the light.

[0273] 10, a negative electrode 108, a positive electrode 107, and an auxiliary electrode 106 are arranged in a container 102. A terminal electrode 202b is connected to the negative electrode 108, and the terminal electrode 202b is extended to the outside of the container 102.

[0274] A terminal electrode 202a is connected to the positive electrode 107, and the terminal electrode 202a is extended to the outside of the container 102. A terminal electrode 202c is connected to the auxiliary electrode 106, and the terminal electrode 202c is extended to the outside of the container 102. The container 102 is filled with electrolyte solutions 104 and 105.

[0275] An electrode voltage control circuit 114 is connected to the terminal electrode 202, and hydrogen is generated by controlling the voltage between the negative electrode 108 and the positive electrode 107. The generated hydrogen is taken out of the container via a hydrogen outlet hole 203. A pipe 110, a gas collector 109, a gas flow meter 411, etc. are attached to the hydrogen outlet hole 203.

[0276] The container 102 is formed with an inlet hole 507 and an outlet hole 508 for the electrolyte 104. The electrolyte circulator 111 injects and discharges the electrolyte 104 through the inlet hole 507 and the outlet hole 508.

[0277] A light-transmitting window 504 is arranged or configured on at least one surface of the container 102. A light-generating device 117 is arranged outside the container 102. The light-generating device 117 is configured or configured so that light 118 from the light-generating device 117 can be irradiated onto the positive electrode 107 of the container 102 through the light-transmitting window 504 of the container 102.

[0278] The light generating device 117 is exemplified by, for example, a backlight of an LCD. The light generating device 117 generates light 118 and irradiates the light 118 onto the auxiliary electrode 106 and the positive electrode 107 through the light transmitting window 504.

[0279] Fig. 2 shows a configuration in which one hydrogen outlet hole 203 is formed or arranged in the container 102. Fig. 20 shows a configuration in which multiple hydrogen outlet holes 203 are formed or arranged in the container 102. The hydrogen outlet hole 203 is not limited to one or multiple holes. For example, one surface of the container 102 may be made sponge-like, and hydrogen gas may be extracted into the container 102 through holes in the sponge.

[0280] 2, 10, and 20 show configurations including an auxiliary electrode 106, but the present invention is not limited to this. For example, in FIG. 19, a negative electrode 108 and a positive electrode 107 are disposed in a container 102. An auxiliary electrode 106 is not provided.

[0281] A terminal electrode 202b is connected to the negative electrode 108, and the terminal electrode 202b is drawn out to the outside of the container 102. A terminal electrode 202a is connected to the positive electrode 107, and the terminal electrode 202a is drawn out to the outside of the container 102.

[0282] 19 shows a configuration in which a plurality of hydrogen outlet holes 203 are formed or arranged in the container 102. The hydrogen outlet holes 203 are not limited to one or more holes. For example, one surface of the container 102 may be made sponge-like or mesh-like, and hydrogen gas may be taken out into the container 102 through the holes in the sponge or mesh.

[0283] An electrode voltage control circuit 114 is connected to the terminal electrode 202, and hydrogen is generated by controlling the voltage between the negative electrode 108 and the positive electrode 107. A piping 110, a gas collector 109, a gas flow meter 411, etc. are attached to the hydrogen outlet hole 203.

[0284] A light-generating device 117 is disposed or configured on at least one surface of the container 102. The light-generating device 117 generates light 118 and irradiates it onto the positive electrode 107. The light-generating device 117 is controlled by a light-generation control circuit 122.

[0285] As shown and explained in FIG. 9, the light generating device 117 may be formed with a structure in which optical fibers or the like are aggregated, and light generated from sunlight, external light, an LED lamp (not shown), or an HID lamp (not shown) may be guided through the optical fibers.

[0286] The light 118 emitted from the light generating device 117 is irradiated onto the auxiliary electrode 106, and the auxiliary electrode 106 is highly sensitive to the visible light 118. Therefore, [Fe III (ox)3] 4- is reduced to.

[0287] As described above, if sunlight is introduced through glass fiber or a light generating device 117 such as a backlight for an LCD is used, [Fe III (ox)3] 3-is reduced to [Fe II (ox)3] 4- Naturally, [Fe III (ox)3] 3- Electrically, [Fe II (ox)3] 4- can be returned to.

[0288] In addition, since the oxidation-reduction potential is 0.02 V, the switch circuit 116b of the electrode voltage control circuit 114 and the variable DC power supply 112 are operated to short-circuit or apply voltage between the positive electrode 107 and the auxiliary electrode 106, thereby forming [Fe II (ox)3] 4- can be reduced to It goes without saying that the positive electrode 107 and the auxiliary electrode 106 may be short-circuited or a voltage may be applied therebetween and the light 118 may be irradiated at the same time. It is also possible to short-circuit or apply a voltage between the positive electrode 107 and the auxiliary electrode 106 and to irradiate the light 118 at the same time.

[0289] [Fe III (ox)3] 3- [Fe II (ox)3] 4- When reducing or changing the hydrogen production process to hydrogen, the switch circuit 115a is turned off. The light irradiation process and the hydrogen production process are preferably performed reversibly, and the reversible operation is preferably performed at a fixed cycle. This fixed cycle is preferably 10 seconds or more and 60 seconds or less.

[0290] 3 is an explanatory diagram of electrodes such as a light-generating device 117 and an auxiliary electrode 106 as an embodiment. The auxiliary electrode 106 is in a mesh shape as shown in FIG. 3(a). Alternatively, it is configured as a plate or sheet with through-holes formed in a matrix. By making the auxiliary electrode 106 in a mesh shape or with through-holes, the area of ​​contact between the auxiliary electrode 106 and the electrolyte 105 is increased, thereby increasing efficiency.

[0291] Light 118 from light generator 117 is irradiated onto auxiliary electrode 106, passes through holes (mesh holes, through-holes) in auxiliary electrode 106, is reflected by separator 119b and positive electrode 107, and is irradiated onto auxiliary electrode 106 again. By forming the separator 119b and the positive electrode 107 from a material having a light diffusing effect, the light 118 is scattered or diffused by the separator 119b and the like.

[0292] In addition, when the refractive index of separator 119b differs from the refractive index of electrolyte solutions 104a, 104b, and 105, the difference in refractive index causes light scattering. A diffusing agent may be mixed into electrolyte solutions 105 and 104. The diffusing agent may be a material (liquid or particulate) having a refractive index different from that of electrolyte solutions 105 and the like. The same applies to the positive electrode 107 and the negative electrode 108, in that the electrodes are in a mesh shape or have a plurality of holes formed therein.

[0293] 3(b), the light generating device 117 has a reflector 301 or a reflector sheet 301 disposed on the back surface of a light guide plate 302 or a light guide sheet 302 made of a transparent resin such as acrylic. A light diffusion plate 303 or a light diffusion sheet 303 is disposed on the light exit surface of the light guide plate 302 or the like.

[0294] The light generating device 117 constitutes or forms a part of the hydrogen generator 201. Therefore, the container 102 is configured so that at least one surface thereof is light-transmitting, and is configured so that light 118 is irradiated onto the auxiliary electrode 106 disposed or formed within the container 102.

[0295] A white LED (not shown) is disposed at one end of the light generating device 117 to generate light 118 , and the light 118 such as sunlight can be guided to the light guide plate 302 .

[0296] The effect of the photoreaction due to light irradiation is basically the reduction of metal ions. In the embodiment of the present invention, the Fe IIIThis example shows that the complex is reduced. As a source of light, sunlight is infinite and does not incur any energy costs, making it environmentally friendly (eco-friendly).

[0297] Semiconductors that generate electrons when exposed to light (optical semiconductor devices, optical semiconductor materials) and Fe III When the complex is brought into contact with the water and irradiated with sunlight, Fe III The complex is then treated with Fe II It is possible to reduce it to a complex, which involves only an electron transfer and no decomposition.

[0298] Examples of optical semiconductor devices include LEDs, LEDs, photodiodes, and phototransistors, and examples of optical semiconductor materials include GaP, AlInGaP, GaAs, GaAlAs, InGaAs, InGaAsP, InP, CdS, Si, and Ge.

[0299] The present invention uses all or part of these optical semiconductor devices and optical semiconductor materials, and III It comes into contact with or electrically connects to a complex or the like.

[0300] Specifically, as hydrogen is produced, Fe II (CN)6 is Fe III Oxidized to (CN)6. Fe III When the complex is brought into contact with an optical semiconductor and irradiated with light, Fe II It can be reduced to a complex. However, if light is irradiated without an optical semiconductor, cyanide gas may be generated. By combining these with other embodiments of the present invention, hydrogen can be produced more efficiently with less power consumption. 2, 10, 19, 20, etc., the container 102 is illustrated as being button-shaped or rectangular, but is not limited to this. In the embodiments of the present invention, the positive electrode 107, the negative electrode 108, etc. are expressed as fixed, but the present invention is not limited to this.

[0301] Figure 18 shows an embodiment of the present invention in the case of a cylindrical or circular configuration. Figure 18(b) is a schematic explanatory diagram of the hydrogen production device as viewed from above. Figure 18(a) is a schematic explanatory diagram of the cross section of the side. The shape of the housing is not limited to a cylindrical shape. It may be a rectangular parallelepiped, plate-like, button-like, or the like.

[0302] The positive electrode 107, negative electrode 108, and auxiliary electrode 106 are configured to be rotatable around axis C. For example, the positive electrode 107 rotates in a clockwise (R) direction, and the auxiliary electrode 106 rotates in a counterclockwise (L) direction. The negative electrode 108 may be rotatable or fixed. The positive electrode 107 and auxiliary electrode 106 may be rotatable or fixed.

[0303] By rotating the electrodes (positive electrode 107, negative electrode 108, auxiliary electrode 106), the positional relationship between the electrodes (positive electrode 107, negative electrode 108, auxiliary electrode 106) changes. This improves the efficiency of hydrogen production, and the rotation also allows the electrolyte 104 and other components to be stirred.

[0304] 18, one or more of the positive electrode 107, negative electrode 108, and auxiliary electrode 106 rotates around axis C, but this is not limiting. For example, it goes without saying that one or more of the electrode 107, negative electrode 108, and auxiliary electrode 106 may be moved or vibrated continuously or intermittently in the horizontal or left-right direction.

[0305] Figure 21 is an explanatory diagram of an automobile using the hydrogen production device of the present invention. The automobile's motor starts and operates using the generated hydrogen as fuel. As shown in Figure 11, by closing (turning on) the switch circuit 116, the voltage is boosted and charged into a rechargeable battery (not shown), and the hydrogen is used as power for a motor having an inverter circuit as a load 505 or as auxiliary starting power.

[0306] Hydrogen generators are a safe, convenient alternative to high-pressure hydrogen gas cylinders. They are more cost-effective. Hydrogen has approximately half the viscosity of helium, so using hydrogen as carrier gas increases sample analysis throughput. The present invention does not generate carbon dioxide during hydrogen production, and because only a small voltage is applied during hydrogen separation, it is environmentally friendly and can produce hydrogen with low power consumption. In the electrolysis of water, instead of oxidizing water (generating oxygen) at the positive electrode, an iron (II) complex is oxidized, which reduces the applied voltage for hydrogen production by about half compared to conventional methods.

[0307] The iron(II) complex is oxidized to form the iron(III) complex, which must be returned to its original state. The graphite and the capacitor are then joined to a third electrode, which uses Na4[Fe as the active material, and an electric current is passed through the electrode. II An auxiliary electrode containing [Fe (ox)3] or an iron(III) complex is connected to the negative electrode of the capacitor to convert it back to an iron(II) complex. III (CN)6] 3- →[Fe II (CN)6] 4- Since the potential of is +0.36V, the reaction proceeds spontaneously.

[0308] Although the load of the capacitor is small, it still requires capacity to reduce iron(III). The electrochemical method using a capacitor is more efficient than the photoreduction method using an auxiliary electrode. [Industrial Applicability]

[0309] According to the present invention, hydrogen can be easily generated with low power consumption, and a low-cost hydrogen production device and hydrogen production method can be provided. [Explanation of symbols]

[0310] 101 Control circuit 102 Container 103 Stirring fan 104 Electrolyte 105 Electrolyte 106 Auxiliary electrode 107 Positive electrode 108 Negative electrode 109 Gas collector 110 Piping 111 Electrolyte circulator 112 Variable DC power supply 114 Electrode voltage control circuit 115 Switch Circuit 116 Switch Circuit 117 Light Generator 118 light 119 Separator 120 Gas reservoir 121 Salt Bridge 122 Light generation control circuit 201 Hydrogen generator (hydrogen production device) 202 Terminal electrode 203 Hydrogen outlet hole 301 Reflector 302 Light guide plate 303 Diffuser 401 Applied current (voltage) control device 403 Pump 404 filter 405 Solenoid valve 407 Liquid Tank 408 Gas Separation Tank 409 Level Detector 410 Hair dryer 411 Gas flow meter 501 Hydrogen Production Unit 502 Condenser Lens 503 Optical Fiber 504 Light-transmitting window 505 Load 506 Cavity 507 Inflow hole 508 Outlet Hole 509 Light Diffuser 510 Heater 511 Motor 512 Ammeter

Claims

1. A positive electrode containing Prussian blue or a hexacyanoferrate complex, a negative electrode, a sodium salt aqueous solution filled between the positive electrode and the negative electrode, a first power source for applying a first voltage between the positive electrode and the negative electrode, A hydrogen production apparatus comprising a hydrogen collector for collecting hydrogen generated from the negative electrode.

2. A positive electrode containing Prussian blue or a hexacyanoferrate complex, a negative electrode, a sodium salt aqueous solution filled between the positive electrode and the negative electrode, a first power source for applying a first voltage between the positive electrode and the negative electrode, Comprising a hydrogen collector for collecting hydrogen generated from the negative electrode, Configured so that light can be irradiated on the positive electrode, A hydrogen production apparatus characterized in that the positive electrode can be reduced by the irradiation of the light.

3. A positive electrode containing Prussian blue or a hexacyanoferrate complex, a negative electrode, a sodium salt aqueous solution filled between the positive electrode and the negative electrode, a first power source for applying a first voltage between the positive electrode and the negative electrode, An auxiliary electrode containing a trisoxalatoiron complex, A hydrogen collector for collecting hydrogen generated from the negative electrode, A hydrogen production apparatus comprising a second power source for applying a second voltage between the positive electrode and the auxiliary electrode.

4. The sodium salt aqueous solution is any one of an aqueous sodium carbonate solution, an aqueous sodium hydrogen carbonate solution, an aqueous sodium phosphate solution, and disodium hydrogen phosphate, The hydrogen production apparatus according to claim 1 or claim 2 or claim 3, wherein the pH of the aqueous solution is greater than 2.

5. The hydrogen production apparatus according to claim 1 or claim 2 or claim 3, characterized in that a separator made of a cation exchange membrane is disposed between the positive electrode and the negative electrode.

6. Applying a voltage between a positive electrode containing Prussian blue or a hexacyanoferrate complex and a negative electrode disposed in an aqueous sodium salt solution, Collecting hydrogen generated at the negative electrode, A hydrogen production method characterized by applying a voltage to the positive electrode to reduce the positive electrode.

7. Applying a voltage between a positive electrode containing Prussian blue or a hexacyanoferrate complex and a negative electrode disposed in an aqueous sodium salt solution, Collecting hydrogen generated at the negative electrode, A hydrogen production method characterized by irradiating light on the positive electrode to reduce the positive electrode.

8. A voltage is applied between a positive electrode containing Prussian blue or a hexacyanoferrate complex disposed in an aqueous sodium salt solution and a negative electrode, hydrogen generated at the negative electrode is collected, and an auxiliary electrode containing a trisoxalatoferrate complex is connected to the positive electrode to reduce the positive electrode, and a hydrogen production method characterized by this.

9. A voltage is applied between a positive electrode containing Prussian blue or a hexacyanoferrate complex disposed in an aqueous sodium salt solution and a negative electrode, hydrogen generated at the negative electrode is collected, an auxiliary electrode containing a trisoxalatoferrate complex is connected to the positive electrode, and the auxiliary electrode is irradiated with light to photoreduce the auxiliary electrode, and a hydrogen production method characterized by this.

10. The hexacyanoferrate complex is a hexacyanoferrate (II) complex, and the hydrogen production method according to claim 6 or claim 7 or claim 8 or claim 9, characterized in that the hexacyanoferrate (II) complex is changed to a hexacyanoferrate (III) complex by the generation of hydrogen.

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