WO2007011073A1 - Passive hydrogen generator and packaged fuel cell power generation system using same - Google Patents

Abstract

Disclosed is a passive hydrogen generator for generating a gas containing hydrogen by decomposing a fuel containing an organic matter. This hydrogen generator comprises a diaphragm (11), a fuel electrode (12) arranged on one surface of the diaphragm (11), a means for supplying a fuel containing an organic matter and water to the fuel electrode (12), an oxidation electrode (14) arranged on the other surface of the diaphragm (11), a means for supplying an oxidizing agent to the oxidation electrode (14), and a means for generating and taking out a gas containing hydrogen on the fuel electrode side. This hydrogen generator is characterized in that (a) the fuel containing an organic matter and water is supplied to the fuel electrode (12) by capillary force (17) or gravitational fall, (b) the oxidizing agent is the air and supplied to the oxidation electrode (14) by natural diffusion (18) or natural convection, or (c) the oxidizing agent is a liquid containing hydrogen peroxide and supplied to the oxidation electrode (14) by capillary force or gravitational fall. This hydrogen generator is also characterized in that a region (14M) where supply of the oxidizing agent is deficient is provided on the side of the oxidation electrode (14).

Description

 Passive type hydrogen production apparatus and package type fuel cell power generation apparatus using the same

Technical field .

 The present invention relates to a passive hydrogen production apparatus for producing a gas containing hydrogen by decomposing a fuel containing organic substances at a low temperature and a package type fuel cell power generation apparatus using the same. Background art

 As a technique for producing a gas containing hydrogen by decomposing a fuel containing organic matter at a low temperature, a method and an apparatus for generating hydrogen by an electrochemical reaction are known, and hydrogen generated by such an electrochemical method is known. There are known fuel cells that use (see Patent Literature:! ~ 4).

 Patent Document 1: Japanese Patent No. 3328993

 • Patent Document 2: Japanese Patent No. 3360349

 Patent Document 3: US Pat. No. 6,299,744, US Pat. No. 6,368,492, US Pat. No. 6,432,284, US Pat. No. 6,533,919 Description, US Patent Publication No. 2003/0226763

 Patent Document 4: JP 2001-297779 A

Patent Document 1 states that “a pair of electrodes is provided on both opposing surfaces of a cation exchange membrane, and a fuel containing at least methanol and water is brought into contact with an electrode including a catalyst provided on one side, and the pair of electrodes is contacted. By applying a voltage to the electrode and extracting electrons from the electrode, a reaction for generating hydrogen ions from the methanol and water is allowed to proceed on the electrode, and the generated hydrogen ions are converted into the cation exchange membrane. A hydrogen generation method characterized in that an electrode provided on the other side of a pair of opposed surfaces is converted into hydrogen molecules by supplying electrons. ”(Claim 1) Water or steam is supplied to the fuel electrode together with methanol as fuel, and the fuel is burned through an external circuit. By applying a voltage to extract electrons from the fuel electrode,

CH ₃ ○ H + 2H ₂ ○ → C ○ ₂ + 6 e + 6 H ⁺ reaction proceeds, the hydrogen ions generated in this way pass through the cation exchange membrane, and on the counter electrode side, 6H ⁺ + 6 e— → 3H ₂ indicates that hydrogen is selectively generated (paragraphs [00 33] to [003 8]). Further, Patent Document 2 describes the generation of hydrogen by this method. An invention of a fuel cell using hydrogen is described (paragraphs [0052] to [00 56]). According to the inventions described in Patent Documents 1 and 2, hydrogen can be generated at a low temperature (Patent Document 1, paragraph [0042], Patent Document 2, paragraph [0080]). Therefore, it is necessary to apply a voltage, and hydrogen is generated on the counter electrode side of the fuel electrode (fuel electrode), and does not supply oxidant to the counter electrode. This is clearly different from the passive hydrogen production system.

 In the invention described in Patent Document 3, as in the inventions described in Patent Documents 1 and 2, the proton generated at the anode 11 12 serving as the fuel electrode permeates the diaphragm 110 and acts as a counter electrode. Hydrogen is generated at the sword 1 14, with the fuel electrode as the anode and the counter electrode as the power sword, voltage is applied from the DC power source 120, and organic fuel such as methanol is pumped at the anode 1 (fuel electrode) 1 1 2 is supplied for electrolysis, and hydrogen is generated on the opposite side of the fuel electrode and not for supplying oxidant to the counter electrode. It is clearly different from the device.

Patent Document 4 describes that in a fuel cell system, a hydrogen generating electrode for generating hydrogen is provided (Claim 1). However, “Porosic electrode (fuel electrode) 1 contains alcohol and water. When the liquid fuel containing is supplied, air is supplied to the gas diffusion electrode (oxidant electrode) 2 on the opposite side, and a load is connected between the terminal of the porous electrode 1 and the terminal of the gas diffusion electrode 2, the normal fuel An electrical connection is established such that a positive potential is applied to porous electrode 1 via a load from gas diffusion electrode 2 which is the positive electrode of ME A 2 having the battery function, and as a result, alcohol reacts with water. Carbon dioxide and hydrogen ions are generated, and the generated hydrogen ions are generated as hydrogen gas at the central gas diffusion electrode 6 via the electrolyte layer 5. In the gas diffusion electrode 6, another electrolyte layer 7 is generated. An electrode reaction occurs at the interface with hydrogen ions again It is to move in the electrolyte layer 7 to reach the gas diffusion electrode 2. Moth The diffusion electrode 2 reacts with oxygen in the air to produce water. (Paragraph [0007]), hydrogen is generated at the hydrogen generation electrode (gas diffusion electrode 6) using the electric energy generated by the fuel cell and supplied to the fuel cell. Yes, it is the same as Patent Documents 1 to 3 in that hydrogen is generated on the opposite side of the fuel electrode.

 In addition, a voltage is applied by using a reactor equipped with a diaphragm in which an anode (electrode A) and a cathode (electrode B) are formed through a proton conductive membrane (ion conductor), or applied. The invention of a method for oxidizing alcohol (methanol) without taking out electric energy or taking out electric energy is also known (see Patent Documents 5 and 6). In either case, the alcohol is oxidized using an electrochemical cell. It is related to the process (products are carbonic acid diester, formalin, methyl formate, dimethoxymethane, etc.), and is not a process that generates hydrogen as a reduction product from the viewpoint of alcohol. Patent Document 5: JP-A-6-73582 (Claims 1 to 3, paragraph [0050]) Patent Document 6: JP-A-6_73583 (claims 1, 8, paragraphs [0006 ·], [00 1 9] ])

 'And any of the above-mentioned technologies forcibly supplies liquid fuel such as methanol to the fuel electrode with a pump or the like, and thus requires auxiliary energy for driving the pump or the like. It was. In addition, there is a limit to downsizing the system.

 In addition, liquid fuel direct supply fuel cells (direct methanol fuel cells) are known to supply liquid fuel to the fuel electrode by capillary action (capillary force) or gravity drop (for example, Patent Documents 7 and 8). In addition, it is known to supply air to the air electrode by natural diffusion or natural convection (see, for example, Patent Documents 9 and 11).

 Patent Document 7: Japanese Patent Application Laid-Open No. 59-66066 'Patent Document 8: Japanese Patent Application Laid-Open No. 6-188008

 Patent Document 9: Japanese Unexamined Patent Publication No. 2003-272697

 Patent Document 10: Japanese Patent Laid-Open No. 2003-28891 8

Patent Document 11: Japanese Patent Laid-Open No. 2004-253197 According to the inventions described in Patent Documents 7 to 11, a pump for supplying liquid fuel to the fuel electrode and a blower for supplying air to the air electrode are not required, and it is small in size and has auxiliary energy. Passive direct methanol fuel cells that are not required can be obtained, but they all relate to fuel cells and do not suggest application to hydrogen production equipment.

Also, for direct methanol fuel cells (DM FC), when the open circuit is oxygen-deficient, the cell reaction and the electrolysis reaction coexist in a single cell, and CH ₃ OH + H ₂ 0 → Non-patent Documents 1 and _{2 that} the reaction of C 0 ₂ + 6 H ⁺ + 6 e—, the reaction of 6 H + + 6 e— → 3 H ₂ occurs at the fuel electrode, and hydrogen is generated from the fuel electrode side. However, Non-Patent Document 1 states that "Hydrogen generation not only reduces the power output in the operating cell, but also continuously consumes fuel in an open circuit condition." Therefore, it is important that the DM FC keep supplying oxygen to the power sword at both the operating and standby levels. ” For DM FCs with A area, the hydrogen caused by the system's shirtdown and startup Neither is intended to produce hydrogen because they conclude that they need to be careful about accumulation.

 Non-Patent Document 1: Electrochemical and Solid-State Letters, 8 (1) A52-A54 (2005) Non-Patent Document 2: Electrochemical and Solid-State Letters, 8 (4) A211-A214 (2005) Disclosure of the Invention

 Problems to be solved by the invention

 The present invention solves the problems as described above, and can produce a gas containing hydrogen at a low temperature, and is small in size, and uses a passive hydrogen production apparatus that does not require auxiliary energy. It is an object of the present invention to provide a packaged fuel cell power generator. Means for solving the problem.

In order to solve the above problems, the present invention employs the following means. (1) In a hydrogen production apparatus that decomposes a fuel containing organic matter to produce a gas containing hydrogen, a diaphragm, a fuel electrode provided on one surface of the diaphragm, and a fuel containing organic matter and water in the fuel electrode Or means for supplying by gravity drop, an oxidizing electrode provided on the other surface of the diaphragm, means for supplying an oxidizing agent to the oxidizing electrode, and means for generating and taking out gas containing hydrogen from the fuel electrode side. And the passive-type hydrogen production apparatus characterized by providing the area | region where supply of the said oxidizing agent is insufficient on the oxidation electrode side.

 (2) In a hydrogen production apparatus for decomposing a fuel containing organic matter to produce a gas containing hydrogen, a diaphragm, a fuel electrode provided on one surface of the diaphragm, and supplying a fuel containing organic matter and water to the fuel electrode Means, an oxidizing electrode provided on the other surface of the diaphragm, means for supplying air as an oxidizing agent to the oxidizing electrode by natural diffusion or natural convection, and means for generating and taking out a gas containing hydrogen from the fuel electrode side. And a passive hydrogen production apparatus characterized in that a region where the supply of the oxidizing agent is insufficient is provided on the oxidation electrode side.

(3) The means for supplying the air by natural diffusion or natural convection has an air intake facing the air electrode that is the oxidation electrode, and has an adjustment valve at the air intake. (2) The passive type hydrogen production apparatus.

 (4) The passive type of (2), wherein the means for supplying the air by natural diffusion or natural convection has a sliding air intake facing the air electrode as the oxidation electrode. Hydrogen production equipment.

 (5) The passive hydrogen production apparatus according to any one of (2) to (4), further including a fan for assisting natural diffusion or natural convection of the air.

 (6) In a hydrogen production apparatus for decomposing a fuel containing organic matter to produce a gas containing hydrogen, a diaphragm, a fuel electrode provided on one surface of the diaphragm, and supplying a fuel containing organic matter and water to the fuel electrode Means, an oxidation electrode provided on the other surface of the diaphragm, means for supplying a liquid containing hydrogen peroxide as an oxidant to the oxidation electrode by capillary force or gravity drop, and generating a gas containing hydrogen from the fuel electrode side. A passive-type hydrogen production apparatus comprising a means for taking out and providing a region where supply of the oxidizing agent is insufficient on the oxidation electrode side. '

(7) In the above (1) to (6), the region where the supply of the oxidizing agent is insufficient is provided without using an oxidation electrode separator having a flow channel for flowing the oxidizing agent. One of the passive type hydrogen production equipment.

 (8) The passive hydrogen production apparatus according to any one of (1) to (7), wherein a region where the supply of the oxidizing agent is insufficient is provided in a gas diffusion layer of the oxidation electrode.

(9) The passive hydrogen production apparatus according to (8), wherein the region where the supply of the oxidizing agent is insufficient is provided by masking a part of the gas diffusion layer of the oxidation electrode. '

 (10) Any one of the above (1) to (7), wherein the region where the supply of the oxidant is insufficient is provided by masking only a part of the gas diffusion layer of the fuel electrode. Passive hydrogen production equipment.

 (1 1) Masking the region where the supply of the oxidant is insufficient on a part of the gas diffusion layer on both sides of the oxidation electrode and the fuel electrode, and shifting at least a part of the masking on both opposing sides. Characterized in that it is provided by performing

(1) The passive hydrogen production apparatus according to any one of (9).

 (12) The passive hydrogen production apparatus according to any one of (9) to (11), wherein the masking is performed in a band shape.

 (13) The passive hydrogen production apparatus according to any one of (9) to (11), wherein the masking is performed in a spot shape.

 (14) The passive-type hydrogen according to any one of (9) to (13), wherein the masking is performed by impregnating the gas diffusion layer with a resin or applying a resin to a surface of the gas diffusion layer. Manufacturing equipment.

 (15) The passive hydrogen production apparatus according to any one of (9) to (14), wherein the masking is performed by screen printing.

 (16) The passive hydrogen production apparatus according to (8), wherein the region where the supply of the oxidant is insufficient is provided with the gas diffusion layer of the oxidation electrode being non-uniform.

 (17) The passive-type hydrogen production apparatus according to (16), wherein the gas diffusion layer of the oxidation electrode is made non-uniform by forming it densely or by combining seams made of different materials. '

(18) The passive hydrogen production apparatus according to (16) or (17), wherein the gas diffusion layer of the oxidation electrode is made uneven by forming irregularities on the surface. (19) The open circuit having no means for taking out electric energy from the hydrogen production cell constituting the hydrogen production apparatus and means for applying electric energy from the outside to the hydrogen production cell. 1) Passive type hydrogen production apparatus according to any one of (18). '

 (20) The passive hydrogen production apparatus according to any one of (1) to (18), further comprising means for taking out electric energy to the outside using the fuel electrode as a negative electrode and the oxidation electrode as a positive electrode. .

(21) The passive hydrogen according to any one of (1) to (18), characterized in that it has means for applying electric energy from outside using the fuel electrode as a force sword and the oxidation electrode as an anode. Manufacturing equipment.

 (22) The passive hydrogen production apparatus according to any one of (1) to (21), wherein a voltage between the fuel electrode and the oxidation electrode is 400 to 600 mV.

(23) The amount of the gas containing hydrogen is adjusted by adjusting a voltage between the fuel electrode and the oxidation electrode, wherein any one of the above (1) to (22) Passive hydrogen production equipment.

 (24) adjusting the supply amount of the oxidant to adjust the voltage between the fuel electrode and the oxidation electrode and the generation amount of gas containing Z or the hydrogen. ) The passive hydrogen production apparatus according to any one of (23).

 (25) The passive hydrogen production apparatus according to any one of (1) to (24), wherein the operating temperature is 100 ° C or lower.

 (26) The organic substance supplied to the fuel electrode is one or two or more organic substances selected from the group consisting of alcohol, aldehyde, carboxylic acid, and ether. 25) Any one of the passive hydrogen production apparatuses.

(27) The passive hydrogen production apparatus according to (26), wherein the alcohol is methanol. '

(28) wherein the diaphragm is a proton conductive solid electrolyte membrane

(1) The passive hydrogen production apparatus according to any one of (27).

(29) The passive hydrogen production apparatus according to (28), wherein the proton conductive solid electrolyte membrane is a perfluorocarbon sulfonic acid solid electrolyte membrane. (30) The passive hydrogen production apparatus according to any one of (1) to (29), wherein the catalyst of the fuel electrode is a platinum-ruthenium alloy supported on carbon powder.

 (3 1) The passive hydrogen production apparatus according to any one of (1) to (30), wherein the catalyst of the oxidation electrode is obtained by supporting platinum on carbon powder.

 (32) The passive hydrogen production apparatus according to any one of (1) to (31), wherein a circulating means for fuel containing the organic matter is provided. .

(33) The passive hydrogen production apparatus according to any one of (1) to (32), wherein a carbon dioxide absorption unit that absorbs carbon dioxide contained in the gas containing hydrogen is provided.

 (34) The passive hydrogen production apparatus according to any one of (1) to (33) is connected to a passive solid polymer fuel cell, and the passive type polymer fuel cell is passively connected to the fuel electrode. A package type fuel cell power generator characterized by supplying a gas containing hydrogen produced by a hydrogen production device.

 (35) The passive hydrogen production apparatus according to any one of the above (1) to (33) is connected to an active solid polymer fuel cell, and passively connected to the fuel electrode of the active solid polymer fuel cell. A package type fuel cell power generator characterized by supplying a gas containing hydrogen produced by a type hydrogen production device. ,

 (36) The package type fuel cell device according to (34) or (35), characterized in that a carbon dioxide absorbing section for absorbing carbon dioxide contained in the gas containing hydrogen is provided.

(37) The package type fuel cell power generator according to (36), wherein the carbon dioxide absorption part is provided in the vicinity of a fuel electrode of a passive solid polymer fuel cell. Here, in (1), (2) and (6), “providing a region where the supply of the oxidant is insufficient on the oxidation electrode side” means that the discharge reaction is suppressed on the oxidation electrode side, and hydrogen This means that a region where the supply of oxidant is insufficient is provided so that the reaction occurs, masking a part of the gas diffusion layer of the oxidation electrode as in (9) and (11), or The gas diffusion layer of the oxidation electrode is formed densely as in (16) to (18), When a region where the supply of oxidant is insufficient is provided directly in the gas diffusion layer of the oxidation electrode by combining different materials or making it non-homogeneous by means such as forming irregularities ((8 However, the present invention is not limited to this, and the supply of the oxidant to the oxidation electrode side by means such as masking only a part of the gas diffusion layer of the fuel electrode as described in (10). It also includes the case where a region lacking is indirectly provided.

 As the masking shape, strips and spots can be adopted as in (1 2) and (1 3), and as the masking material, resin can be adopted as in (14). As a means of masking, force capable of adopting impregnation, coating and screen printing as in the above (14) and (15) Masking shape, material and means are not limited to these, Any shape, material, and means may be included as long as the region where the supply of the oxidizing agent is insufficient can be formed on the side.

In addition, in the above (7), “Do not use an oxidation electrode separator provided with a flow channel for flowing an oxidant” means that an oxidant (air) such as that found in a conventional direct methanol fuel cell is flowed. This means that an oxidation electrode separator provided with a flow channel groove is not used. Further, the passive hydrogen production apparatus according to the above (1) to (6) and (19) ′ to (21) has means for supplying fuel and an oxidant to the hydrogen production cell. In addition, in the case of (20), there is a discharge control means for taking out electric energy from the hydrogen production cell. In the case of (21), electric energy is supplied to the hydrogen production cell. Electrolytic means for applying is provided. The case (19) is an open circuit type that does not have a discharge control means for taking out electric energy from the hydrogen production cell and an electrolysis means for applying electric energy to the hydrogen production cell. The passive hydrogen production apparatuses of (1) to (6) include the passive hydrogen production apparatuses of (19) to (21). Furthermore, these passive hydrogen production apparatuses monitor the voltage of the hydrogen production cell and / or the generation amount of gas containing hydrogen, and supply and concentration of fuel and oxidant, as well as electric energy to be extracted (20 )) Or applied electric energy (in the case of (21) above). The basic structure of the hydrogen production cell constituting the passive hydrogen production apparatus is that a fuel electrode is provided on one surface of the diaphragm, and fuel is supplied to the fuel electrode. A structure for supplying an oxide electrode on the other surface of the diaphragm, and a structure for supplying an oxidizing agent to the oxide electrode. The invention's effect

 By adopting the passive hydrogen production apparatus of the present invention, the fuel can be reformed at a temperature much lower than the conventional reforming temperature from room temperature to 1 oo ° C or less. It requires less energy, and the gas containing hydrogen does not contain nitrogen in the air, or the amount of contamination is very low and does not contain CO. If a gas is obtained and a CO removal process is not required, a lame effect is obtained.

 Further, the passive hydrogen production apparatus of the present invention can generate hydrogen without supplying electric energy to the hydrogen production cell from the outside, but even if it has a means for taking out electric energy, Hydrogen can be generated even when a means for applying electrical energy is provided.

 If there is a means for extracting electrical energy, the electrical energy can be used effectively.

 Even when a means for applying electric energy from the outside is provided, by supplying a small amount of electric energy from the outside to the hydrogen production cell, it is possible to generate one or more hydrogens of the input electric energy. .

 Furthermore, in any case, process control is possible by monitoring the voltage of the hydrogen production cell and / or the amount of gas containing hydrogen, thereby reducing the size of the hydrogen production equipment. As a result, the cost of the apparatus can be reduced.

 In addition, since a pump for supplying liquid fuel to the fuel electrode and a blower for supplying air to the air electrode are not necessary, auxiliary energy can be saved, and a package using hydrogen production equipment and hydrogen production equipment. The type fuel cell power generator can be further reduced in size.

If separators are not used, the hydrogen production system should be made more compact. It has the effect of being able to. Brief Description of Drawings

 FIG. 1 (a) is a diagram showing an example of a passive hydrogen production apparatus having a regulating valve at the air intake.

 FIG. 1 (b) is a diagram showing an example of a passive hydrogen production apparatus having a sliding air intake.

 FIG. 1 (c) is a diagram showing an example of a passive hydrogen production apparatus having a fan for assisting natural diffusion or natural convection.

 FIG. 1 (d) is a front view of a passive hydrogen production apparatus having a large number of air intake ports used in the examples. .

 FIG. 1 (e) is a perspective view of a passive hydrogen production apparatus having a large number of air intake ports used in the examples.

 FIG. 2 is a schematic diagram showing a reaction in the discharge region of the fuel electrode and the air electrode of the passive hydrogen production apparatus of the present invention.

 FIG. 3 is a schematic view showing the reaction in the hydrogen generation region of the fuel electrode and the air electrode of the passive hydrogen production apparatus of the present invention.

 FIG. 4 is a schematic view showing the total reaction at the fuel electrode and the air electrode of the passive hydrogen production apparatus of the present invention.

 FIG. 5 is a schematic view showing an example of MEA in which a mask is provided on a part of the surface of the air electrode used in the passive hydrogen production apparatus of the present invention.

 FIG. 6 is a schematic view showing an example of ME A in which a mask is provided on a part of the surface of the fuel electrode.

 FIG. 7 is a schematic view showing an example of MEA in which a mask is provided on part of the surface of the fuel electrode and the air electrode so as to face the same position.

 FIG. 8 is a schematic view showing an example of ME A provided with a mask on a part of the surface of the fuel electrode and the air electrode so as not to face the opposite positions. .

Fig. 9 shows the mask facing part of the surface of the fuel electrode and air electrode, with only part of the mask facing. It is the schematic which shows an example of ME A provided by shifting by half so that.

 FIG. 10 is a schematic diagram showing the width, interval, and number of masks provided on part of the surfaces of the fuel electrode and the air electrode.

 FIG. 11 is a schematic view showing M EA used in the hydrogen production cell of the example of the present invention.

 Fig. 12 is a schematic diagram showing an example in which the gas diffusion layer of the air electrode is made non-uniform by combining different materials. Fig. 13 is a schematic diagram showing an example in which the gas diffusion layer of the air electrode is made non-uniform by the combination of density.

 Fig. 14 is a schematic diagram showing an example in which the gas diffusion layer of the air electrode is made uneven due to surface irregularities.

 Fig. 15 is a diagram showing an example of a passive hydrogen production system that naturally diffuses both fuel and air.

 Fig. 16 is a diagram showing an example of a passive hydrogen production system in which fuel is naturally dispersed and air is supplied by a blower.

 Fig. 17 is a diagram showing an example of a passive hydrogen production system in which fuel is supplied by a pump and air is naturally diffused.

 Fig. 18 is a diagram showing the relationship between the open voltage and the hydrogen production rate when hydrogen is generated using a passive hydrogen production system that naturally diffuses both fuel and air. FIG. 19 is a diagram showing an example of a packaged fuel cell power generation apparatus in which a passive hydrogen production apparatus is connected to a passive polymer electrolyte fuel cell.

 Fig. 20 is a diagram showing an example of a packaged fuel cell power generation device in which a passive hydrogen production device is connected to a passive solid polymer fuel cell (with a carbon dioxide absorber in the vicinity of the fuel electrode). is there.

 FIG. 21 is a diagram showing an example of a packaged fuel cell power generator in which a passive hydrogen production device is connected to an active polymer electrolyte fuel cell.

(Explanation of symbols)

1 0 Hydrogen production cell 1 1 Diaphragm 1 2 Fuel electrode 1 Mask provided on part of gas diffusion layer of 2M fuel electrode

 1 3 Flow path for supplying fuel (organic methanol solution) containing organic matter and water to the fuel electrode 1 2

 14 Oxidizing electrode (Air electrode)

 14M Mask provided on part of gas diffusion layer of oxidation electrode (air electrode)

 1 5 Flow path for supplying oxidizing agent (air) to oxidizing electrode (air electrode) 14

 16 Fuel cartridge 1 7 Member made of capillary material (porous material).

18 Air intake 1 9 Adjustment valve

 20 Slide member 21 Fan

 22 Passive polymer electrolyte fuel cell

 23 Passive polymer electrolyte fuel cell membrane

 24 Fuel electrode of passive polymer electrolyte fuel cell

 25 Air electrode of passive polymer electrolyte fuel cell 26 Carbon dioxide absorber 27 Active polymer electrolyte fuel cell

 28 Fuel Pump 29 Air Blower 30 Radiator BEST MODE FOR CARRYING OUT THE INVENTION

 The best mode for carrying out the present invention will be illustrated below.

 In particular, the passive hydrogen production apparatus of the present invention is fundamentally novel, and what is described below is only one form, and the present invention is not limited thereby.

 The present inventors have developed a hydrogen production device (Japanese Patent Application No. 2004-367792) that uses a cell with the same structure as a conventional direct methanol fuel cell to decompose fuel containing organic matter and produce gas containing hydrogen. In addition, we developed a passive-type hydrogen production system and a packaged fuel cell power generation system (Japanese Patent Application No. 2005-148774) using this.

In any of the hydrogen production apparatuses in the above invention, an oxidation electrode separator provided with a flow channel for flowing an oxidant is used, but without using a separator, It was discovered that hydrogen was generated by providing a region where the supply of oxidant was insufficient on the oxidation electrode side, and the invention of a hydrogen production device, etc. (Japanese Patent Application No. 2005-164145) was completed. Relates to the improved invention.

 Fig. 1 (a) to Fig. 1 (c) show an example of the passive hydrogen production apparatus of the present invention.

 This example has means for supplying a fuel containing organic matter and water to the fuel electrode of the hydrogen production cell by capillary force.

 The structure of the hydrogen production cell (10) has a fuel electrode (12) on one side of the diaphragm (11), and a flow path for supplying fuel (aqueous methanol solution) containing organic matter and water to the fuel electrode (12). (13), an oxidation electrode (14) provided on the other surface of the diaphragm (1 1), and a flow path (15) for supplying oxidant (air) to the oxidation electrode (14) Is.

 In the passive hydrogen production apparatus of the present invention, an organic or inorganic fiber material such as paper, cotton, synthetic fiber, asbestos, or glass is used as a base material in the flow path (1 3) for supplying fuel. A member (17) made of the capillary material (porous body) is arranged, and the capillary force of the capillary material sucks up fuel from the fuel cartridge (16) and supplies it to the fuel electrode (12).

 As shown in the figure, masks (12M) and (14M) face only part of the gas diffusion layers of the fuel electrode (12) and air electrode (14), and only parts of the masks (12M) and (14M) face each other. The fuel is supplied from the part other than the mask (12M) to the fuel electrode (12), and the air supply to the air electrode (14) is insufficient as will be described later. Is formed.

 Instead of supplying fuel by capillary force, it can also be supplied by gravity drop.

In the case of gravity drop, a fuel cartridge ( ₁₆ ) is provided at the top, and the fuel is supplied to the fuel electrode by dropping the fuel through the fuel guide. 'The amount of fuel supply can be adjusted by changing the position of the fuel tank in the case of gravity drop or by providing a valve structure at the outlet of the fuel tank. It can be adjusted by changing the material of the material. Also, when using a liquid containing hydrogen peroxide as an oxidizer, it contains organic matter. As with fuel and water, a liquid containing hydrogen peroxide can be supplied to the oxidation electrode by capillary force or gravity drop.

 In particular, in the case of a liquid containing hydrogen peroxide, the amount of hydrogen-containing gas generated varies greatly depending on the supply amount, so optimal hydrogen generation can be achieved by adjusting the supply amount as described above. It is preferable to adjust so that it may become quantity.

 Furthermore, the passive hydrogen production apparatus of the present invention can be used when the oxidant is air.

As shown in (&) to Fig. 1 (6), air can be supplied to the oxidation electrode (air electrode) by natural diffusion or natural convection.

 It has at least one air intake (18) for introducing air as an oxidant gas from the atmosphere by natural diffusion or natural convection. Figures 1 (d) and 1 (e) show a large number of air intakes.

 As shown in the reference example described later, the amount of hydrogen-containing gas generated varies greatly depending on the air supply amount. Therefore, a regulating valve (19) is installed in part or all of the inlet of the air intake port (18). It is preferable to adjust so that the optimal hydrogen generation amount is obtained by providing a slide member (20) at the air intake (18) and providing a slide-type air intake.

 Since the passive hydrogen production apparatus of the present invention supplies air to the air electrode by natural diffusion or natural convection, it does not require auxiliary equipment such as a blower for supplying air to the air electrode. However, as shown in Fig. 1 (c), a fan (21) for assisting natural diffusion or natural convection may be provided.

 The hydrogen generation reaction mechanism in the passive hydrogen production apparatus of the present invention is estimated as follows.

 In the region of sufficient supply of oxidant (oxygen) provided on the oxidation electrode (air electrode) side (hereinafter referred to as “discharge region”), the following discharge reaction in a normal fuel cell, that is, as shown in FIG. Thus, reaction (A) occurs on the fuel electrode side and reaction (B) occurs on the air electrode side. '

(A) CH ₃ OH + H ₂ 0 → 6H ⁺ + 6 e_ + C〇 ₂

(B) 6 H + + 6 e— + 3/20 ₂ → 3H ₂ 〇

—When using proton conductive solid electrolyte membrane such as naphthion, CH ₃ OH Is known to pass through the fuel electrode to the air electrode side. In the region where oxygen supply is insufficient on the air electrode side (hereinafter referred to as the “hydrogen generation region”), the reaction (B) As shown in Fig. 3, the crossover methanol is electrolytically oxidized and the reaction (D) occurs. On the other hand, the hydrogen generation reaction (C) occurs on the fuel electrode side.

(C) 6 H + + 6 e— → 3 H ₂

(D) CH ₃ OH + H ₂ 0 → 6H ⁺ + 6 e— + C 0 ₂

 In the case of the hydrogen production apparatus of the invention according to claim 19 of the present application (hereinafter referred to as “open circuit conditions”), e-generated by the reactions (A) and (D) passes through the external circuit. Therefore, H + and e- produced by the reaction (A) at the fuel electrode move to the air electrode and the H + and e- fuel electrode produced by the reaction (D) at the air electrode. The move to is apparently counteracted.

• That is, as shown in Fig. 4, H + and e- produced by the reaction (A) in the discharge region on the fuel electrode side move to the hydrogen generation region on the same fuel electrode side, and the reaction (C) H, and hydrogen is generated. On the other hand, H ⁺ and e- produced by the reaction (D) in the hydrogen generation region on the air electrode side move to the same discharge region on the air electrode side, and (B) It is estimated that this reaction is occurring.

 Assuming that the reactions (A) and (C) proceed on the fuel electrode and the reactions (B) and (D) proceed on the oxidation electrode, the following reactions are established as a whole.

2CH ₃ 〇_H _{+ 2H 2 0 + 3/20} 2 → 2C0 2 + 3H 2 0 + 3H 2

 The theoretical efficiency of this reaction is 59% (3 mol of hydrogen exothermic Z 2 mol of methanol generated heat).

 The invention according to claim 20 of the present application “having means for taking out electric energy to the outside with the fuel electrode as a negative electrode and the oxidation electrode as a positive electrode”

This is called “discharge condition”. In the case of), hydrogen is considered to be generated by a mechanism similar to the hydrogen generation mechanism under open circuit conditions. However, unlike in the case of open circuit conditions, it is necessary to maintain the electrical neutral conditions of the entire cell by moving H + corresponding to the discharge current from the fuel electrode to the air electrode. The reaction (A) is likely to proceed faster (more) than the reaction (D) at the air electrode than the reaction (D). The invention according to claim 21 of the present application “having means for applying electric energy from the outside with the fuel electrode as a force sword and the oxidation electrode as an anode” Hydrogen production apparatus (hereinafter referred to as “charging condition”). In this case, hydrogen is considered to be generated by a mechanism similar to the hydrogen generation mechanism under open circuit conditions. However, unlike open circuit conditions, it is necessary to maintain the electrical neutral conditions of the entire cell by moving H ⁺ corresponding to the electrolysis current from the air electrode to the fuel electrode. The reaction (C) is faster than the reaction (C), and the reaction (D) is faster (more) than the reaction (B) at the air electrode.

 When producing the hydrogen production apparatus of the present invention, first, ME A (membrane-electrode assembly) is produced in the same manner as in the conventional direct methanol fuel cell. '' The manufacturing method of ME A as shown in Fig. 5 to Fig. 9 is not limited, but the anode (1 2) consisting of the anode catalyst layer and gas diffusion layer, the air electrode catalyst layer and gas diffusion The air electrode (14) composed of layers can be manufactured by a method similar to the conventional method in which both sides of the diaphragm (11) are bonded by hot pressing.

 In order to provide the air electrode (1 4) with a region where the supply of oxidant (air) is insufficient, a part of the gas diffusion layer (ME A gas diffusion layer) of the air electrode, as shown in FIG. It is preferable to provide a mask (14 M) (masking is performed). '

 Also, as shown in Fig. 6, even if a mask (12M) is provided on part of the gas diffusion layer (MEA gas diffusion layer) of the fuel electrode (12), A small amount of hydrogen is generated. By masking a part of the fuel electrode, the unmasked part increases the diffusion of methanol and water to the air electrode side through the electrolyte, and the masked part of the methanol and water air Diffusion to the pole side is reduced, and as a result, on the air electrode side where methanol has diffused, oxygen is consumed due to oxidation of methanol, and a region where oxygen is insufficient on the air electrode side is formed. On the air electrode side where methanol did not diffuse, oxygen is not consumed, but a region where oxygen exists sufficiently on the air electrode side is formed, which is the same effect as masking a part of the air electrode side. It can be considered that there is an effect.

When masks (1 2M) and (1 4M) are provided respectively in part of the gas diffusion layer of the fuel electrode (1 2) and air electrode (1 4), as shown in the reference example described later, hydrogen Depart May or may not occur.

As shown in Fig. 7, hydrogen is not generated when a mask is provided in part of the gas diffusion layer of the fuel electrode (12) and air electrode (14) so as to face the same position. This is because a hydrogen generation region is formed by providing a mask (14M) in a part of the gas diffusion layer of the air electrode (14), but a mask is formed in the corresponding region of the fuel electrode (12). (1 2M) is provided, so it is thought that methanol does not diffuse for the reaction of (D), and hydrogen generation reaction (C) does not occur. As shown in Fig. 8, hydrogen is not generated when a mask is provided in part of the gas diffusion layer of the fuel electrode (12) and air electrode (14) so as not to face the opposite positions. The reason for this is that a mask (1 2M) is provided in the discharge region of the fuel electrode (1 2), no methanol is supplied, the reaction of (A) does not occur, and H ⁺ and e- are not generated. Therefore, it is thought that H ⁺ and e_ are not supplied from the discharge region to the hydrogen generation region, and the hydrogen generation reaction (C) does not occur.

 As shown in Fig. 9, masks (1 2M) and (1 4 M) are applied to part of the gas diffusion layer of the fuel electrode (1 2) and air electrode (14), and masks (1 2 M) and (1 If only a part of (4 M) is placed in the opposite direction, a discharge region (1) and a hydrogen generation region (2) are formed, and a discharge reaction occurs in the region (1). Since hydrogen generation reaction occurs in the region of 2), hydrogen is generated.

 The shape of the masking (mask) is not limited, but it can be formed in a strip shape as shown in Fig. 10. Masking may be performed in spots.

 The amount of gas containing hydrogen can be adjusted by appropriately setting the width, interval, number, etc., of the strip-shaped masks, the size, number, etc. of the speckled masks.

 A resin such as an epoxy resin can be used as the masking material. Further, as a masking means, it is possible to carry out simply by impregnating the gas diffusion layer, coating, screen printing, sticking a seal, and the like.

In addition to the masking as described above, the gas diffusion layer may be formed densely, the gas diffusion layer may be combined with different materials, or irregularities may be formed on the surface of the gas diffusion layer. By making the electrode gas diffusion layer non-uniform, a region where the supply of the oxidizing agent is insufficient can be provided on the oxidation electrode side. As the ME A membrane (11) in the hydrogen production apparatus of the invention, a proton conductive solid electrolyte membrane used as a polymer electrolyte membrane in a fuel cell can be used. The proton conductive solid electrolyte membrane is preferably a perfluorocarbon sulfonic acid-based membrane having a sulfonic acid group, such as a DuPont Nafion membrane. The fuel electrode and the oxidation electrode (air electrode) are preferably electrodes having conductivity and catalytic activity. For example, a catalyst and PTFE resin supported on a carrier made of carbon powder or the like in a gas diffusion layer. It can be prepared by applying and drying a catalyst paste containing a binder such as a naphthoion solution and a substance for imparting ionic conductivity. The gas diffusion layer is preferably made of carbon paper that has been subjected to water repellent treatment.

 Any fuel electrode catalyst can be used, but a catalyst in which a platinum-ruthenium alloy is supported on carbon powder is preferable.

 Any air electrode catalyst can be used, but a catalyst in which platinum is supported on carbon powder is preferred.

 In the hydrogen production apparatus configured as described above, when a fuel containing organic matter such as a methanol aqueous solution is supplied to the fuel electrode, and an oxidizing agent such as air, oxygen or hydrogen peroxide is supplied to the oxidation electrode (air electrode), Under certain conditions, gas containing hydrogen is generated at the anode.

 In the hydrogen production apparatus of the present invention, the amount of gas containing hydrogen tends to depend on the voltage between the fuel electrode and the oxidation electrode (air electrode). Therefore, the open circuit conditions, discharge conditions, and charge conditions In either case, the amount of gas containing hydrogen can be adjusted by adjusting the voltage (open circuit voltage or operating voltage) between the fuel electrode and the oxidation electrode (air electrode). ·

 In the case of an open circuit condition, as shown in the examples, hydrogen is generated at an open circuit voltage of 400 to 60 O mV. Therefore, by adjusting the open circuit voltage within this range, Therefore, the amount of gas containing hydrogen can be adjusted.

The open circuit voltage or operating voltage and the amount of gas containing Z or hydrogen (hydrogen generation rate) can be adjusted by adjusting the supply of oxidant (air, oxygen, etc.), adjusting the concentration of oxidant, and organic matter. It can be adjusted by adjusting the amount of fuel containing fuel and adjusting the concentration of fuel containing organic matter. In addition to the above, in the case of discharge conditions, adjust the electrical energy extracted outside (adjust the current extracted outside, and use a power source capable of constant voltage control, a so-called potentio stud. Therefore, in the case of charging conditions, adjust the electric energy to be applied (by adjusting the applied current, and further, the power supply capable of constant voltage control). By adjusting the voltage applied by using a potentiostat), the operating voltage and the amount of gas containing hydrogen or hydrogen can be adjusted. In the hydrogen production apparatus of the present invention, the fuel containing organic matter can be decomposed at 1 oo ° C. or lower, so that the operating temperature of the hydrogen production apparatus can be made 10 ° C. or lower. The operating temperature is preferably 30 to 90 ° C. By adjusting the operating temperature in the range of 30 to 90 ° C, the open circuit voltage or operating voltage and the amount of gas containing Z or hydrogen can be adjusted as shown in the following examples.

 In the conventional reforming technology that required operation at 100 ° C or higher, water turns into steam, fuel containing organic matter gasifies, and even if hydrogen is generated under such conditions, The present invention is advantageous in this respect because it is necessary to separately use a means for separating hydrogen.

 However, when the fuel containing organic matter is decomposed at a temperature of 100 ° C or higher, there are the above-mentioned disadvantages, but the present invention operates the hydrogen production apparatus of the present invention at a temperature slightly exceeding 100 ° C. It is not a denial of making it happen.

 Considering the presumed principle, the fuel containing organic matter may be a liquid or gaseous fuel that passes through a Proton conductive membrane and is oxidized electrochemically to produce Proton, such as methanol, A liquid plate containing an alcohol such as ethanol, ethylene glycol or 2-propanol, an aldehyde such as formaldehyde, a carboxylic acid such as formic acid, or an ether such as jetyl ether is preferred. Since fuel containing organic matter is supplied together with water, a solution containing alcohol and water, and an aqueous solution containing methanol is preferred. Note that the aqueous solution containing methanol as an example of the fuel described above is a solution containing at least methanol and water, and the concentration thereof can be arbitrarily selected in a region where a gas containing hydrogen is generated.

As the oxidant, a gas or liquid oxidant can be used. Gas oxidation As the agent, a gas containing oxygen or oxygen is preferable. The oxygen concentration of the gas containing oxygen is

10% or more is particularly preferable. A liquid containing hydrogen peroxide is preferred as the liquid oxidant.

 In the present invention, since the fuel input to the passive hydrogen production apparatus is consumed once in the apparatus and decomposed into hydrogen is low, a fuel circulation means is provided to increase the conversion rate to hydrogen. It is preferable.

 The passive hydrogen production apparatus of the present invention includes means for extracting a gas containing hydrogen from the fuel electrode side, and recovers hydrogen, but it is also preferable to recover carbon dioxide. Since it operates at a temperature as low as 10 ° C. or less, a carbon dioxide absorption part that absorbs carbon dioxide contained in a gas containing hydrogen can be provided by simple means. Next, reference examples of the present invention (hydrogen production examples) will be shown. The ratio of the catalyst, PTFE, naphthion, etc., the thickness of the catalyst layer, gas diffusion layer, electrolyte membrane, etc. can be appropriately changed. It is not limited by.

 In Reference Examples 1 to 4 and Comparative Examples 1 and 2, active hydrogen production equipment with a region where air supply is insufficient on the air electrode side (fuel is supplied by a fuel pump, and air is supplied by an air blower. This shows an example of producing hydrogen under an open circuit condition using a hydrogen production apparatus to be supplied.

(Reference Example 1)

 A hydrogen production cell was prepared as follows.

In other words, a DuPont proton conductive electrolyte membrane (Nafion 1 115) was used as the electrolyte, and carbon paper (Toray) was immersed in the 5% polytetrafluoroethylene dispersion at the air electrode. An air electrode catalyst prepared by mixing the air electrode catalyst (platinum-supported carbon: made by Tanaka Kikinzoku), PTF E 'fine powder, and 5% Nafion solution (made by Aldrich) on one side. The paste was applied to form a gas diffusion layer with an air electrode catalyst. Here, the weight ratio of the air electrode catalyst, PTFE, and Nafion was set to 65%: 15%: 20%. Air electrode produced in this way The amount of the catalyst was 1 mgZcm ² in terms of platinum.

Furthermore, using the same method, carbon paper was treated with water repellency, and on one side, a fuel electrode catalyst (platinum ruthenium-supported carbon: manufactured by Tanaka Kikinzoku), PTFE fine powder, and a 5% Nafion solution were mixed. A paste was applied to form a gas diffusion layer with a fuel electrode catalyst. Here, the weight ratio of the fuel electrode catalyst, PTFE, and naphthion was 55%: 1 5%: 30%. The catalyst amount of the fuel electrode produced in this way was lmg / cm ² in terms of platinum-ruthenium. The above electrolyte membrane, gas diffusion layer with air electrode catalyst, and gas diffusion layer with fuel electrode catalyst. ME A was prepared by hot pressing with C, 1 OMPa. The effective electrode area of MEA produced in this way was 60.8 cm ² (80 mm long and 76 mm wide). The thickness of the catalyst layer of the air electrode and fuel electrode after fabrication, and the thickness of the gas diffusion layer of the air electrode and fuel electrode were approximately the same at about 30 μπι and 1.70 | im, respectively. The outline of the prepared ME A is shown in Fig. 11.

 By applying epoxy resin only on the air electrode gas diffusion layer of MEA produced as described above, as shown in Fig. 5 and Fig. 10, eight strip masks with a width of 5 mm are provided at intervals of 5 mm. It was. The MEA created in this way is provided with an air electrode side end plate with an air inlet and an air outlet on the air electrode side through silicon rubber, and the fuel inlet and fuel exhaust on the fuel electrode side. A fuel electrode side end braid provided with an outlet is arranged via silicon rubber, stacked and sandwiched so that fuel is supplied to the surface of the fuel electrode, so that air is supplied to the surface of the air electrode. A space was provided. In addition, in order to prevent fuel and air leakage, silicon rubber packing was provided around the fuel and air electrodes. In order to measure the potential of each electrode, a stainless steel foil in contact with the electrode was inserted between the packing and MEA.

The hydrogen S cell made in this way is installed in a hot air circulation type electric furnace, the cell temperature (operating temperature) is 50 ° C, the air is supplied to the air electrode side at a flow rate of 10-50 ml / min, fuel A 1M aqueous methanol solution (fuel) was flowed to the pole side at a flow rate of 5.0 m 1 min, and the voltage difference (open voltage) between the fuel electrode and the air electrode at that time and the amount of gas generated on the fuel electrode side were measured. . · Underwater displacement method was used to measure the amount of gas generated. In addition, the hydrogen concentration in the generated gas The hydrogen production rate was determined by analysis by S-chromatography.

 The results are shown in Table 1.

 table 1

 As shown in Table 1, generation of hydrogen was confirmed from the fuel electrode side of the cell by reducing the air flow rate. In addition, when the relationship between the air flow rate and the open circuit voltage (OCV) of the cell was examined, it was found that the cell open circuit voltage tended to decrease with decreasing air flow rate.

 The rate of hydrogen generation (hydrogen generation amount) tends to depend on the open circuit voltage.

It was found that hydrogen was generated at 4 0 0 to 6 0 O mV. The peak of the hydrogen production rate was observed at around 50 O mV.

(Reference Example 2)

 Reference Example, except that eight strip masks with a width of 5 mm were provided at intervals of 5 mm as shown in Fig. 6 and Fig. 10 by applying an epoxy resin only on the fuel electrode gas diffusion layer of MEA A hydrogen production cell was prepared in the same manner as in 1, and the amount of gas generated on the fuel electrode side was measured in the same manner as in Reference Example 1. '

 The results are shown in Table 2. .

 Table 2

As shown in Table 2, the generation of a small amount of hydrogen was confirmed from the anode side of the cell at an open circuit voltage of about 50 O mV by reducing the air flow rate.

(Comparative Example 1)

 By applying an epoxy resin on the gas diffusion layers of the fuel electrode and air electrode of ME A, as shown in Fig. 7 and Fig. 10, eight strip masks with a width of 5 mm, A hydrogen production cell was prepared in the same manner as in Reference Example 1 except that it was placed so as to face the same position, and the amount of gas generated on the fuel electrode side was measured as in Reference Example 1.

 The results are shown in Table 3.

 Table 3

 As shown in Table 3, generation of hydrogen was not confirmed from the fuel electrode side of the cell even when the air flow rate was reduced.

 This is because, as described above, the hydrogen generation region of the fuel electrode is masked, and methanol diffusion for the hydrogen generation reaction cannot be performed.

(Comparative Example 2)

 By applying epoxy resin on the gas diffusion layers of the fuel electrode and air electrode of the MEA, as shown in Fig. 8 and Fig. 1 '0, a strip mask with a width of 5 mm is spaced at intervals of 5 mm. A hydrogen production cell was prepared in the same manner as in Reference Example 1 except that 8 electrodes were provided on the electrode and 6 electrodes were provided on the air electrode so as not to face each other, and gas generated on the fuel electrode side as in Reference Example 1 The amount was measured. '

The results are shown in Table 4. Table 4

 As shown in Table 4, generation of hydrogen was not confirmed from the fuel electrode side of the cell even when the air flow rate was reduced.

 This is because, as described above, the region where the discharge reaction of the fuel electrode should occur is masked, and methanol cannot be supplied for the discharge reaction.

(Reference Example 3)

 A hydrogen production cell was prepared in the same manner as in Reference Example 1 using ME A prepared in a separate outlet, and the amount of gas generated on the fuel electrode side was measured in the same manner as in Reference Example 1.

 The results are shown in Table 5. Table 5

 As shown in Table 5, hydrogen generation was confirmed from the fuel electrode side of the cell at a slightly higher air flow rate than in Reference Example 1. In addition, when the relationship between the air flow rate and the open circuit voltage of the cell was examined, it was found that the cell open circuit voltage tended to decrease with decreasing air flow rate.

The hydrogen generation rate (hydrogen generation amount) tended to depend on the open circuit voltage, and it was found that hydrogen was generated at an open circuit voltage of 400 to 60 mV. The peak of hydrogen production rate was observed around 47 mV. (Reference Example 4)

 By applying an epoxy resin on the gas diffusion layer of the fuel electrode and air electrode of the MEA, as shown in Fig. 9 and Fig. 10, eight strip masks with a width of 5 mm are provided at intervals of 5 mm. A hydrogen production cell was fabricated in the same manner as in Reference Example 3 except that only a part of the mask was shifted so as to face each other, and the amount of gas generated on the fuel electrode side was measured in the same manner as in Reference Example 1.

 The results are shown in Table 6. Table 6

 As shown in Table 6, hydrogen generation was confirmed from the fuel electrode side of the cell at an open circuit voltage of around 50 O mV by reducing the air flow rate.

 When the mask is shifted, as described above, a discharge region and a hydrogen generation region are formed, and hydrogen is generated.

(Reference Example 5)

 Next, instead of masking a part of the gas diffusion layer, a reference example in which the gas diffusion layer of the air electrode is made non-uniform by a combination of different materials and an area where air supply is insufficient is provided on the air electrode side. Show.

Fig. 12 shows a polyimide sheet (air blocking layer) with a width of 1 O mm and carbon paper (air permeable layer: gas diffusion layer with an air electrode catalyst) with a width of 1 O mm on the air electrode side of the electrolyte membrane. In addition, the carbon film (gas diffusion layer with fuel electrode catalyst) is placed on the fuel electrode side of the electrolyte membrane, and hot-pressed at 140 ° C and '1 OMPa. A MEA was prepared in the same manner as in Example 1 except that bonding was performed using The thickness of the polyimide sheet was 1 30 μm before and after pressing, and the thickness of the carbon paper was 2 80 μ πι before pressing and 1 65 μm after pressing (polyimide sheet). Can be restored by pressing). The thickness of the catalyst layer of the air electrode and fuel electrode after pressing was about 30 μm, respectively.

 Using the ME A thus produced, a hydrogen production cell was produced in the same manner as in Reference Example 1, and the amount of gas generated on the fuel electrode side was measured in the same manner as in Reference Example 1.

 The results are shown in Table 7.

 Table 7

 Even if the gas diffusion layer of the air electrode is made uneven by combining different materials,

As shown in Fig. 7, generation of hydrogen was confirmed from the fuel electrode side of the cell at an open circuit voltage of about 50 mV by reducing the air flow rate.

(Reference Example 6)

 Next, instead of masking part of the gas diffusion layer, a reference example in which the gas diffusion layer of the air electrode is made non-uniform by the combination of density and an area where air supply is insufficient is provided on the air electrode side. Show.

A thin carbon paper (gas diffusion layer with air electrode catalyst) with a width of 1 O mm and a thickness of 190 μm and a thick carbon paper with a width of 1 O mm and a thickness of 3 3 5 μπι on the air electrode side of the electrolyte membrane. A thin carbon paper (a gas diffusion layer with a fuel electrode catalyst) with a thickness of 190 μm is placed on the fuel electrode side of the electrolyte membrane. Then, MEA was produced in the same manner as in Example 1 except that bonding was performed by hot pressing (simultaneous pressing) at 140 ° C. and the same pressing pressure (l OMP a). The thickness of the carbon paper that is the gas diffusion layer of the air electrode before and after pressing is 1 90 β 0 → 1 65 m, 3 3 5 μ πι → 1 8 5 μ ηι, which is almost the same thickness. Therefore, the carbon paper is a combination of sparse and dense (thin carbon paper, sparse, thick carbon paper ~ dense) as shown in Fig. 13. Air electrode and fuel after pressing Each of the electrode catalyst layers had a thickness of about 30 μηι.

 A hydrogen production cell was produced using ME ME thus produced in the same manner as in Reference Example 1, except that the flow rate of air flowing to the air electrode side was in the range of 10 to 90 m 1 / min. Using the same conditions as in Example 1, the amount of gas generated on the fuel electrode side was measured. The results are shown in Table 8.

 Table 8

 Even if the gas diffusion layer of the air electrode is made non-uniform by the combination of density, as shown in Table 8, by reducing the air flow rate, the open circuit voltage is around 50 OmV from the fuel electrode side of the cell. Generation of hydrogen was confirmed. Hydrogen was generated where the air flow rate was slightly higher than in Reference Example 5 where the gas diffusion layer of the air electrode was made non-uniform by combining different materials. '

(Reference Example 7)

 Next, instead of masking part of the gas diffusion layer, a reference example is shown in which the gas diffusion layer of the air electrode is made non-uniform due to surface irregularities and an area where air supply is insufficient is provided on the air electrode side. .

On the air electrode side of the electrolyte membrane, a thin carbon paper (gas diffusion layer with an air electrode catalyst) with a width of 1 Omm and thickness of 1 90 μm is arranged with a gap of 1 Omm, and on the fuel electrode side of the electrolyte membrane. A thin carbon paper (gas diffusion layer with fuel electrode catalyst) with a thickness of 1 90 μπι is placed on the entire surface, hot-pressed at 140 ° C and 10 MPa pressure, and then into the 1 Omm gap. Example except that thick carbon paper (gas diffusion layer with air electrode catalyst) with a thickness of 335 μm was lined up and bonded by hot pressing with a press pressure of 140 ° C and 1 OMPa (two-stage pressing) ME A was prepared as in 1. The thickness of the carbon paper that is the gas diffusion layer of the air electrode before and after pressing is 1 90 m → 1 40 m, 3 3 5 μm → 2 1 5 μm, and the unevenness (thin carbon paper ~ ^ concave, thick carbon paper ""> It is a carbon paper with protrusions. The thickness of the catalyst layer of the air electrode and fuel electrode after pressing was about 30 μιη respectively.

 A hydrogen production cell was produced using MEΑ thus produced in the same manner as in Reference Example 1, except that the flow rate of air flowing to the air electrode side was in the range of 10 to 9 O m 1 Z. The amount of gas generated on the fuel electrode side was measured using the same conditions as in Reference Example 1. The results are shown in Table 9.

 Table 9

 Even if the gas diffusion layer of the air electrode is made uneven due to unevenness on the surface, as shown in Table 9, by reducing the air flow rate, the cell fuel electrode is near the open circuit voltage of 50 O m V. From the side, generation of hydrogen was confirmed. Similar to the combination of Reference Example 6 in which the gas diffusion layer of the air electrode is made non-uniform by a combination of density, compared to the case of Reference Example 5 in which the gas diffusion layer of the air electrode is made non-uniform by a combination of different materials Hydrogen was generated at a slightly higher air flow rate. Example

Using the same MEA as in Reference Example 5 (with a polyimide sheet as the air barrier layer), a flow path is provided to allow air to flow and fuel to flow, respectively. Natural diffusion with fuel and air (Fig. 15) ), Three types of passive hydrogen production equipment were prepared: natural diffusion of fuel, supply of air by blower (Fig. 16), supply of fuel by pump, and natural diffusion of air (Fig. 17). As a means of natural fuel diffusion, as shown in FIGS. 15 and 16, a member made of a capillary material is arranged in a flow path for supplying fuel, and the capillary of the capillary material is arranged. A means was used to suck up fuel from the fuel cartridge by force and supply it to the fuel electrode. As a means of natural air diffusion, as shown in Fig. 15 and Fig. 17, we adopted a means to naturally diffuse air by forming a number of air intakes facing the air electrode.

 The hydrogen production device shown in Fig. 15 was used to supply air from the air intake port to the air electrode side by natural diffusion at an operating temperature of 30 ° C, without using an air blower or fuel pump. Then, the 1.OM methanol aqueous solution (fuel) in the fuel cartridge is supplied to the fuel electrode side, the voltage difference between the fuel electrode and the air electrode (open voltage) at that time, and the hydrogen generation rate generated on the fuel electrode side Study was carried out.

 The results are shown in Figure 18.

 Open circuit voltage (open voltage) Hydrogen generation from the fuel electrode side of the cell was confirmed at around 50 mV.

 In the passive hydrogen production system shown in Fig. 15 and Fig. 17 that diffuses air naturally, it was difficult to generate hydrogen continuously, but air was supplied by a blower and burned. In the passive hydrogen production system as shown in Fig. 16 where natural gas diffuses naturally, it is thought that hydrogen can be generated continuously. As described above, the hydrogen production apparatus provided with a region where air supply is insufficient on the air electrode side can produce a gas containing hydrogen by decomposing a fuel containing organic matter at 100 ° C. or lower. Therefore, if this is a passive hydrogen production system, a pump for supplying fuel containing organic matter and water to the fuel electrode and a blower for supplying air to the air electrode are not necessary. This saves energy and makes the hydrogen production system even smaller. Next, application of this passive hydrogen production apparatus will be described.

As shown in FIG. 19, the passive hydrogen production apparatus of the present invention is connected to a passive solid polymer fuel cell (2 2) to connect the fuel electrode of the passive solid polymer fuel cell (2 By supplying a gas containing hydrogen produced by a passive hydrogen production device to 4), a package type fuel cell power generation device can be obtained. Passive solid The polymer fuel cell (2 2) has a fuel electrode (2 4) on one side of the diaphragm (2 3) and an air electrode (2 5) on the other side of the diaphragm (2 3). Conventional ones can be used.

 In the vicinity of the anode (2 4) of the passive polymer electrolyte fuel cell (2 2), as shown in FIG. 20, an alkali for absorbing carbon dioxide contained in the gas containing hydrogen, It is preferable to provide a carbon dioxide absorption part (2 6) made of zeolite.

 In addition, as shown in FIG. 21, the passive hydrogen production apparatus of the present invention has a conventional active solid polymer fuel cell (2 7) having a fuel pump (2 8) and an air blower (2 9). ) And supplying a gas containing hydrogen produced by a passive hydrogen production device to the fuel electrode of an active solid polymer fuel cell, thereby providing a packaged fuel cell power generator. .

 Although not shown in the figure, when combined with an active solid polymer fuel cell, a carbon dioxide absorption section is provided between the hydrogen production cell (1 0) and the radiator (3 0) of the passive hydrogen production apparatus. Can also be provided. Industrial applicability

 The package type fuel cell power generation apparatus using the passive hydrogen production apparatus of the present invention as described above does not require any special means for protecting the control device built in the package from the heat generated by the hydrogen production apparatus. Furthermore, since the entire device including the fuel cell does not generate much heat, it is extremely advantageous when used as a mobile power source or an on-site power source.

Claims

The scope of the claims

1. In a hydrogen production apparatus for decomposing a fuel containing organic matter to produce a gas containing hydrogen, a diaphragm, a fuel electrode provided on one surface of the diaphragm, and a material containing organic matter and water in the fuel electrode is subjected to capillary force or soot A means for supplying by dropping, an oxidation electrode provided on the other surface of the diaphragm, a means for supplying an oxidant to the oxidation electrode, and a means for generating and taking out a gas containing hydrogen from the fuel electrode side, And the passive-type hydrogen production apparatus characterized by providing the area | region where supply of the said oxidizing agent is insufficient on the oxidation electrode side.

 2. In a hydrogen production apparatus for decomposing a fuel containing organic matter and producing a gas containing hydrogen, a diaphragm, a fuel electrode provided on one surface of the diaphragm, means for supplying a fuel containing organic matter and water to the fuel electrode, An oxidizing electrode provided on the other surface of the diaphragm; means for supplying air as an oxidizing agent to the oxidizing electrode by natural diffusion or natural convection; and means for generating and taking out a gas containing hydrogen from the fuel electrode side A passive hydrogen production apparatus characterized in that a region where the supply of the oxidizing agent is insufficient is provided on the oxidation electrode side.

 3. The means for supplying the air by natural diffusion or natural convection has an air intake facing the air electrode that is the oxidation electrode, and an adjustment valve at the air intake. The passive hydrogen production apparatus according to claim 2, characterized in that it is characterized in that

 4. The means according to claim 2, wherein the means for supplying the air by natural diffusion or natural convection has a sliding air intake facing the air electrode as the oxidation electrode. The passive-type hydrogen production apparatus described in 1.

 5. The passive hydrogen production apparatus according to any one of claims 2 to 4, further comprising a fan for assisting natural diffusion or natural convection of the air.

6. In a hydrogen production apparatus for decomposing a fuel containing organic matter to produce a gas containing hydrogen, a diaphragm, a fuel electrode provided on one surface of the diaphragm, means for supplying a fuel containing organic matter and water to the fuel electrode, An oxidation electrode provided on the other surface of the diaphragm; means for supplying a liquid containing hydrogen peroxide as an oxidant to the oxidation electrode by capillary force or gravity drop; fuel electrode side A passive hydrogen production apparatus comprising: means for generating and taking out a gas containing hydrogen from a gas; and a region where supply of the oxidant is insufficient is provided on the oxidation electrode side.

 7. The region according to claim 1, wherein the region where the supply of the oxidizing agent is insufficient is provided without using an oxidation electrode separator provided with a channel groove for flowing the oxidizing agent. And a passive hydrogen production apparatus according to any one of items 6 to 6.

 8. The region described in any one of claims 1, 2, and 6, wherein a region where the supply of the oxidizing agent is insufficient is provided in the gas diffusion layer of the oxidation electrode. Passive hydrogen production equipment.

 9. The passive hydrogen according to claim 8, wherein the region where the supply of the oxidant is insufficient is provided by masking a part of the gas diffusion layer of the oxidation electrode. Manufacturing equipment.

 10. The region in which the supply of the oxidant is insufficient is provided by masking only a part of the gas diffusion layer of the fuel electrode. The passive-type hydrogen production apparatus according to any one of claims 6.

 1 1. Mask the region where the oxidant is insufficiently supplied to a part of the gas diffusion layer on both the oxidation electrode and the fuel electrode, and shift at least a part of the masking on both sides facing each other. The passive hydrogen production apparatus according to any one of claims 1, 2, and 6, wherein the passive hydrogen production apparatus is provided.

12. The region where the supply of the oxidant is insufficient is provided by masking a part of the gas diffusion layer of the oxidation electrode and / or the fuel electrode in a band shape. The passive-type hydrogen production apparatus according to any one of items 1, 2, and 6. +

 13. The region where the supply of the oxidant is insufficient is provided by performing spotting on a portion of the gas diffusion layer of the oxidation electrode and Z or the fuel electrode. The passive-type hydrogen production apparatus according to any one of items 1, 2, and 6.

14. In the region where the supply of the oxidant is insufficient, impregnate resin in part of the gas diffusion layer of the oxidation electrode and Z or the fuel electrode, or apply resin to part of the surface of the gas diffusion layer. 7. The passive hydrogen production apparatus according to claim 1, wherein the passive hydrogen production apparatus is provided by masking.

 15. The region where the supply of the oxidant is insufficient is provided by masking screen-printed on a part of the gas diffusion layer of the oxidation electrode and Z or the fuel electrode. The passive hydrogen production apparatus according to any one of items 2 and 6.

 16. The passive hydrogen production apparatus according to claim 8, wherein the region where the supply of the oxidant is insufficient is provided by making the gas diffusion layer of the oxidation electrode non-uniform.

 17. The passive type according to claim 16, wherein the gas diffusion layer of the oxidation electrode is made non-uniform by forming it densely or by combining different materials. Hydrogen production equipment.

 18. The passive hydrogen production apparatus according to claim 16, wherein the gas diffusion layer of the oxidation electrode is made uneven by forming irregularities on the surface.

1 9. An open circuit having no means for extracting electric energy from a hydrogen production cell constituting the hydrogen production apparatus and means for applying electric energy from the outside to the hydrogen production cell. The passive hydrogen production apparatus according to any one of claims 1, 2, and 6.

 20. Any one of claims 1, 2, and 6, further comprising means for taking out electric energy to the outside using the fuel electrode as a negative electrode and the oxidation electrode as a positive electrode. The passive-type hydrogen production apparatus according to item.

 21. The method according to claim 1, further comprising means for applying electric energy from the outside with the fuel electrode as a force sword and the oxidation electrode as an anode. The passive-type hydrogen production apparatus according to item.

 2. The voltage between the fuel electrode and the oxidation electrode is 400 to 60 OmV, and any one of claims 1, 2 and 6 Passive hydrogen production system as described in the section.

2. The amount of generation of the gas containing hydrogen is adjusted by adjusting the voltage between the fuel electrode and the oxidation electrode. The passive-type hydrogen production apparatus according to any one of claims 6.

 24. Range of claim characterized in that by adjusting the supply amount of the oxidant, the voltage between the fuel electrode and the oxidation electrode and the generation amount of gas containing Z or hydrogen are adjusted. The passive-type hydrogen production apparatus according to any one of items 1, 2, and 6.

 25. The passive hydrogen production apparatus according to any one of claims 1, 2, and 6, wherein the operating temperature is 100 ° C. or lower. .

26. The organic material supplied to the fuel electrode is one or more organic materials selected from the group consisting of alcohol, aldehyde, carboxylic acid, and ether. The passive-type hydrogen-made production apparatus according to any one of items 2 and 6. .

 27. The passive hydrogen production apparatus according to claim 26, wherein the alcohol is methanol.

 28. The passive hydrogen production apparatus according to any one of claims 1, 2, and 6, wherein the diaphragm is a proton conductive solid electrolyte membrane.

29. The passive hydrogen production apparatus according to claim 28, wherein the proton conductive solid electrolyte membrane is a perfluorocarbon sulfonic acid solid electrolyte membrane. '

 30. The fuel electrode catalyst according to any one of claims 1, 2, and 6, wherein the catalyst of the fuel electrode is a platinum-ruthenium alloy supported on carbon powder. Passive hydrogen production equipment.

 31. The passive-type hydrogen according to any one of claims ί, 及 び, 及 び, and 極, wherein the catalyst of the oxidation electrode is platinum supported on carbon powder. Manufacturing equipment.

 3. The passive hydrogen production apparatus according to any one of claims 1, 2, and 6, wherein a circulation means for fuel containing the organic matter is provided.

3 3. The carbon dioxide absorption part which absorbs the carbon dioxide contained in the gas containing the said hydrogen was provided, The range of Claim 1 characterized by the above-mentioned Passive hydrogen production system.

3 4. Connecting the passive hydrogen production apparatus according to any one of claims 1, 2 and 6 to a passive solid polymer fuel cell, to form a passive solid polymer type A package type fuel cell power generator characterized by supplying a gas containing hydrogen produced by a passive hydrogen production device to a fuel electrode of a fuel cell.

35. The package type fuel cell power generator according to claim 34, further comprising a carbon dioxide absorbing section that absorbs carbon dioxide contained in the gas containing hydrogen. 36. The package type fuel cell power generator according to claim 35, characterized in that the carbon dioxide absorption part is provided in the vicinity of a fuel electrode of a passive solid polymer fuel cell.

 3 7. Connecting the passive hydrogen production apparatus according to any one of claims 1, 2 and 6 to an active solid polymer fuel cell to form an active solid polymer type A package type fuel cell power generator characterized in that a gas containing hydrogen produced by a passive hydrogen production device is supplied to a fuel electrode of a fuel cell.

 38. The package-type fuel cell power generator according to claim 37, further comprising a carbon dioxide absorber that absorbs carbon dioxide contained in the gas containing hydrogen.