JP2007246953A - Electrolytic cell and hydrogen supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrolytic cell for producing high purity hydrogen from a water soluble organic compound and water by electrochemical reaction. <P>SOLUTION: The electrolytic cell 10 has an anode section 5 to which an aqueous solution of a water soluble organic compound is supplied, an anode 6 arranged in the anode section and having electrode catalyst, an electrolyte film 7 arranged adjacent to the anode 6 and having proton conductivity, a cathode 8 arranged adjacent to the electrolyte film 7 and having an electrode catalyst, a hydrogen selectively permeable part 18 comprising a hydrogen separation film such as a palladium film arranged adjacent to the cathode to selectively permeate hydrogen produced on the cathode 8 and a cathode section 9 in which the cathode 8 and the hydrogen selectively permeable part 18 are arranged and to which hydrogen permeated through the hydrogen selectively permeable part 18 is supplied. High purity hydrogen is recovered as a cathode outlet gas 24 from a hydrogen recovery apparatus 12 adjacent to the cathode section 9. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrolytic cell used for producing hydrogen from a water-soluble organic compound and water, and a hydrogen supply having such an electrolytic cell and producing and supplying hydrogen from the water-soluble organic compound and water. More particularly, the present invention relates to an electrolytic cell capable of producing high-purity hydrogen and a hydrogen supply system capable of performing efficient hydrogen production, hydrogen recovery, and carbon dioxide recovery.

  In recent years, development of fuel cells and cogeneration systems using hydrogen as fuel has been progressing. For example, an electric vehicle (hydrogen fuel cell vehicle) using a fuel cell that uses hydrogen as a fuel is traveling on a public road. Furthermore, in portable devices such as notebook personal computers and mobile phones, it has been studied to use a fuel cell using hydrogen as a power source. In order to popularize hydrogen fuel cell vehicles, hydrogen supply stations that supply hydrogen to hydrogen fuel cell vehicles, that is, hydrogen supply stations like gasoline stations that supply fuel to current gasoline vehicles and diesel vehicles It is necessary to install the system in various places. Therefore, a hydrogen supply system that supplies hydrogen to hydrogen consuming equipment represented by a hydrogen fuel cell vehicle or a cogeneration system that uses hydrogen as a fuel is being studied.

  As one form of the hydrogen supply system, hydrogen is produced off-site, that is, hydrogen is produced at a place other than the hydrogen supply system, and the produced hydrogen is used as a high-pressure hydrogen (gas) or liquid hydrogen consumption site. Non-Patent Documents 1 and 2 disclose a hydrogen supply system that supplies a hydrogen consuming device after transporting to a storage facility. This type of hydrogen supply system is intended to use by-product hydrogen generated in chemical plants, etc., so carbon dioxide, which is a global warming exhaust gas generated during hydrogen production, is collected at the hydrogen production site. It has the advantage that it can be recovered. However, except for the case where a pipeline is laid from the hydrogen production site to the hydrogen consumption site to transport hydrogen, especially in the case of gas, hydrogen, which is a low energy density fuel, is transferred from the hydrogen production site using a tank lorry. It is necessary to transport to a consumption site, and there is a problem that energy loss accompanying transportation is large. Although liquid hydrogen has a higher energy density than high-pressure hydrogen, it requires extremely low temperatures for transportation and handling, is extremely cumbersome, and increases transportation and storage costs. In addition, since the construction of a pipeline for transporting hydrogen costs enormous costs, the hydrogen supply system that produces hydrogen off-site and transports it to the hydrogen-consuming site in a situation where hydrogen consumption is not very high. Is not realistic in terms of economy.

  As another form of the conventional hydrogen supply system, fuel such as desulfurized gasoline, liquefied petroleum gas (LP gas), natural gas (city gas), methanol, naphtha, etc. is consumed on-site, that is, on-site. Non-Patent Documents 3 to 7 disclose hydrogen supply systems that produce hydrogen by reforming and supply the produced hydrogen to a hydrogen consuming device after storage or pressurization / storage, respectively. Of these fuels, natural gas is mainly composed of methane and is widely used as city gas. For this reason, pipelines for transporting natural gas are also widely used. It can be supplied. Liquefied petroleum gas becomes liquid at a pressure of about 0.8 MPa at room temperature, and other fuels are liquid at room temperature and normal pressure, both of which have a higher energy density than hydrogen. It is possible to keep energy loss small even if transported with In these hydrogen supply systems that produce hydrogen by reforming the fuel on-site, it is possible to efficiently produce hydrogen at the hydrogen consumption site, but the carbon dioxide produced by reforming the fuel In addition, it is necessary to separate and pressurize hydrogen from the reformed gas containing water vapor and the like, which has a problem of consuming a lot of energy. In addition, in order to obtain the heat required for fuel reforming by burning the exhaust gas containing carbon dioxide, water vapor, hydrogen, etc. after separating hydrogen from the reformed gas with air, the combustion exhaust gas containing carbon dioxide contains A large amount of nitrogen is contained, and if carbon dioxide is to be separated and recovered from the viewpoint of preventing global warming, a large-scale carbon dioxide separation and recovery device is required, and a large amount of energy is consumed for the separation and recovery of carbon dioxide. There is also a problem.

  Hereinafter, details of the current situation and problems of the conventional hydrogen supply system described above will be described by taking a hydrogen supply system using natural gas as a fuel disclosed in Non-Patent Document 5 as an example.

  FIG. 6 shows a configuration of a conventional hydrogen supply system using natural gas as fuel. This hydrogen supply system includes, as main components, a fuel reformer 59, flow control valves 43 to 46, 57, 65, blowers 47, 58, a hydrogen purifier 25, a hydrogen pressurizer 27, Hydrogen storage units 28 and 40, hydrogen supply devices 30 and 41, and a pump 48 are provided. The fuel reformer 59 heats the desulfurizer 49, the reformer 50, the combustion burner 51 that heats the reformer 50, the CO (carbon monoxide) converter 52, the boiler 53, and the boiler 53. And a combustion burner 54.

  Natural gas 42 as fuel is supplied to the desulfurizer 48 via the flow control valve 43, supplied to the combustion burner 54 via the flow control valve 44, and supplied to the combustion burner 51 via the flow control valve 45. . In addition to the natural gas 42, air 67 is supplied to the combustion burner 54 of the boiler 53 via the blower 47 and the flow control valve 46. The combustion burner of the reformer 50 is supplied with exhaust gas (hydrogen purifier exhaust gas 29), which will be described later, in addition to the natural gas 42, and through a blower 58 and a flow control valve 57. Then, air 56 is supplied. The combustion burners 51 and 54 discharge combustion burner exhaust gas 69 and 70, respectively, with combustion. The boiler 53 is supplied with makeup water 55 via a pump 48.

  In addition to natural gas, a desulfurizer recycle gas 66 recycled from the outlet gas of the CO converter 52 (CO converter outlet gas 64) is supplied to the desulfurizer 49 through a flow control valve 65. Desulfurized natural gas 62 from the desulfurizer 49 (the sulfur component is removed) and steam 61 from the boiler 53 are supplied to the reformer 50, and steam reforming of a hydrocarbon such as methane, which will be described later, is performed in the reformer 50. A quality reaction occurs. The outlet gas from the reformer 50 (reformer outlet gas 60) is then supplied to the CO converter 52. As described above, the CO converter outlet gas 64 is supplied to the hydrogen purifier 25 as the fuel reformer outlet gas 63 except that a part thereof is recycled to the desulfurizer 49.

  The hydrogen purifier 25 purifies hydrogen contained in the fuel reformer outlet gas 63, and the purified hydrogen (high purity hydrogen 26) is supplied to the hydrogen pressurizer 27 and the hydrogen storage unit 40. . The hydrogen purifier exhaust gas 29 generated along with the hydrogen purification in the hydrogen purifier 25 is supplied to the combustion burner 51 as described above. Hydrogen pressurized by the hydrogen pressurizer 27 (pressurized high-purity hydrogen 71) is supplied to the hydrogen storage unit 28. Each of the hydrogen storage units 28 and 40 temporarily stores high-purity hydrogen, and supplies the high-purity hydrogen in the hydrogen storage units 28 and 40 to the external hydrogen consuming device 31, respectively. Hydrogen supply devices 30 and 41 are provided.

  Next, the operation of the hydrogen supply system shown in FIG. 6 will be described.

  The natural gas 42 supplied as city gas through a pipeline or the like is supplied to a fuel reformer 59 having a desulfurizer 49, a reformer 50, a CO converter 52, and the like, and is reformed. 59, a fuel reformer outlet gas 63 that is a hydrogen-rich reformed gas (main components are hydrogen, carbon dioxide, and steam) made of hydrogen, carbon dioxide, steam, methane, and carbon monoxide is generated. . Hereinafter, the reaction process in the fuel reformer 59 will be specifically described.

  The natural gas 42 contains a odorant such as mercaptan, and this odorant contains a sulfur component that causes deterioration of the reforming catalyst charged in the reformer 50. Therefore, in the fuel reformer 59, the natural gas 42 is first supplied to the desulfurizer 49. In the desulfurizer 49, the sulfur component in the natural gas 42 is adsorbed and removed by hydrodesulfurization by the action of the cobalt-molybdenum-based catalyst of the filled desulfurization catalyst and the zinc oxide adsorbent. That is, with a cobalt-molybdenum-based catalyst, sulfur and hydrogen are first reacted to generate hydrogen sulfide, and then hydrogen sulfide and zinc oxide are reacted to generate zinc sulfide, thereby removing the sulfur component. In order to supply the hydrogen necessary for the production of hydrogen sulfide to the desulfurizer 49, as described above, a part of the CO converter outlet gas 64, which is a hydrogen-rich reformed gas with a reduced carbon monoxide concentration, It is recycled to the desulfurizer 49 as desulfurizer recycle gas 66. The supply amount of the desulfurizer recycle gas 66 to the desulfurizer 49 is controlled by adjusting the opening degree of the flow control valve 65. Both the hydrogen sulfide formation reaction and the zinc sulfide formation reaction are endothermic reactions, and the reaction heat necessary for these reactions is the heat generated by the CO shift reaction in the CO shift converter 52, which is an exothermic reaction described later. This can be done by supplying the desulfurizer 49 from the CO converter 52. In order to efficiently perform this heat transfer, it is desirable that the desulfurizer 49 and the CO converter 52 be integrated. The supply amount of the natural gas 42 to the desulfurizer 49 is controlled by adjusting the opening degree of the flow control valve 43.

  The natural gas 62 from which the sulfur component is removed in the desulfurizer 49 is supplied together with the steam 61 to the reformer 50 filled with a nickel-based catalyst or a ruthenium-based catalyst as a reforming catalyst. The steam 61 supplied to the reformer 50 supplies natural gas 42 and air 67 to the combustion burner 54 of the boiler 53, and uses heat generated by burning the natural gas 42 together with oxygen in the air 67. The make-up water 55 supplied to the boiler 53 by the pump 48 is vaporized and generated. The air 67 is supplied to the combustion burner 54 of the boiler 53 by the blower 47. The supply amount of the natural gas 42 to the combustion burner 54 is controlled by adjusting the opening degree of the flow control valve 44, and the supply amount of the air 67 is controlled by adjusting the opening degree of the flow control valve 46.

  In the reformer 50, a steam reforming reaction of a hydrocarbon such as methane contained in the natural gas 42 is performed by the action of the packed reforming catalyst, and a reformer outlet gas 60 that is a hydrogen-rich reformed gas. Is made.

  The steam reforming reaction of methane, which is the main component of natural gas, is expressed by equation (1).

(Methane steam reforming reaction)
CH ₄ + H ₂ O → CO + 3H ₂ (1)
Since the steam reforming reaction of hydrocarbons such as the steam reforming reaction of methane represented by the equation (1) is generally a large endothermic reaction, in order to efficiently generate hydrogen in the reformer 50, steam reforming is performed. The heat of reaction necessary for the quality reaction must be supplied to the reformer 50 from the outside, and the temperature of the reformer 50 must be maintained at, for example, 700 to 750 ° C. For this reason, a hydrogen purifier exhaust gas 29 and air 56 consisting of hydrogen, which will be described later, and carbon dioxide, water vapor, methane, and carbon monoxide as impurities are supplied to the combustion burner 51 of the reformer 50, and the hydrogen purifier By reacting hydrogen or methane in the exhaust gas 29 with oxygen in the air 56, the reaction heat necessary for the steam reforming reaction is supplied to the reformer 50, and the temperature of the reformer 50 is set to 700 to 750 ° C. To maintain. As a result, in the reformer 50, efficient hydrogen generation is performed by a hydrocarbon steam reforming reaction. Air 56 is supplied to the combustion burner 51 of the reformer 50 using a blower 58. The amount of air 56 supplied to the combustion burner 51 of the reformer 50 is controlled by adjusting the opening degree of the flow control valve 57.

  Since the reformer outlet gas 60, which is a hydrogen-rich reformed gas, contains about 10% by volume of carbon monoxide, the reformer outlet gas 60 is a CO shift catalyst such as a copper-zinc catalyst. The carbon monoxide concentration in the reformer outlet gas 60 is reduced to 1% by volume or less by supplying the gas to the CO converter 52 filled with gas and causing the CO conversion reaction shown in the formula (2) to be performed by the action of the CO conversion catalyst. To reduce.

(CO conversion reaction)
CO + H ₂ O → CO ₂ + H ₂ (2)
Since the CO shift reaction here is an exothermic reaction, the generated heat is supplied to the desulfurizer 49, and as described above, the hydrogen sulfide generation reaction and the zinc sulfide generation reaction in the desulfurizer 49, which is an endothermic reaction, are performed. As reaction heat for use. A part of the CO converter outlet gas 64, which is a hydrogen-rich reformed gas whose carbon monoxide concentration is reduced to 1% by volume or less, is supplied to the desulfurizer 49 as the desulfurizer recycle gas 66 as described above. The rest is supplied to the hydrogen purifier 25 as the fuel reformer outlet gas 63.

  The hydrogen concentration of the fuel reformer outlet gas 63, which is a hydrogen-rich reformed gas produced by the fuel reformer 59 and having a carbon monoxide concentration reduced to 1% by volume or less, is about 70% by volume. As described above, the reformer outlet gas 63 contains carbon dioxide, water vapor, methane, and carbon monoxide as impurities. Therefore, impurities in the fuel reformer outlet gas 63 are removed by the hydrogen purifier 25. As the hydrogen purification device 25, for example, a purification device using PSA (Pressure Swing Adsorption) is used, but other types of purification devices may be used. The high-purity hydrogen 26 (for example, hydrogen purity 99.999 volume% or more) from which impurities have been removed by the hydrogen purifier 25 is supplied to and stored in the hydrogen storage units 28 and 40.

  The hydrogen storage unit 40 shown in FIG. 6 is a hydrogen storage alloy tank that stores high-purity hydrogen 26 at a pressure of less than 1 MPa that is not subject to the regulations of the High Pressure Gas Safety Law. Cooling is performed when storing hydrogen in the hydrogen storage alloy tank. The alloy is cooled with water (32 ° C. or lower), and when releasing hydrogen from the hydrogen storage alloy tank, the alloy is heated using warm water (70 ° C. or higher). The hydrogen storage unit 28 is a high-pressure tank and stores, for example, high-purity hydrogen 26 after being pressurized to 40 MPa by a hydrogen pressurizer 27. The pressurized high-purity hydrogen 71 and the high-purity hydrogen 26 stored in the hydrogen storage units 28 and 40, respectively, are respectively supplied to the hydrogen fuel cell vehicle and the home fuel cell cogeneration system of a detached house using the hydrogen supply devices 30 and 41. Supplied directly or using a pipeline to hydrogen consuming equipment 31 such as a residential fuel cell cogeneration system in a housing complex or a commercial fuel cell cogeneration system in a store or factory. In the hydrogen supply devices 30 and 41, the pressurized high-purity hydrogen 71 is depressurized and the high-purity hydrogen 26 is pressurized as necessary according to the rating of the hydrogen consuming equipment 31.

  In such a hydrogen supply system, the hydrogen purifier exhaust gas 29 consisting of hydrogen purified by the hydrogen purifier 25 and impurities carbon dioxide, water vapor, methane, and carbon monoxide is reformed as described above. It is supplied to the combustion burner 51 of the reformer 50 and used to supply the reformer 50 with reaction heat necessary for the reforming reaction of hydrocarbons in the natural gas 42. Note that heat is insufficient only by burning the hydrogen purifier exhaust gas 29 with the combustion burner 51 of the reformer 50, and the hydrocarbons in the natural gas 42 supplied to the reformer 50 are reacted by a reforming reaction. When the necessary amount of reaction heat cannot be supplied to the reformer 50, the natural gas 42 is additionally supplied to the combustion burner 51 of the reformer 50, and the natural gas 42 is combusted with the air 56. The amount of heat supplied to the reformer 50 is increased, and the reformer 50 performs a steam reforming reaction of hydrocarbons in the natural gas 42. In that case, the supply amount of the natural gas 42 to the combustion burner 51 of the reformer 50 is controlled by adjusting the opening degree of the flow control valve 45.

  Next, problems of the hydrogen supply system by reforming as shown in FIG. 6 will be described. In the conventional hydrogen supply system shown in FIG. 6, the reaction heat required to generate hydrogen by performing the steam reforming reaction of hydrocarbons in the natural gas 42 in the reformer 50 of the fuel reformer 59 is as follows. The hydrogen purifier exhaust gas 29 comprising hydrogen and impurities carbon dioxide, water vapor, methane, and carbon monoxide is supplied to the combustion burner 51 of the reformer 50 together with the air 56 and burned, or hydrogen The refiner exhaust gas 29 and the natural gas 42 are supplied to the reformer 50 by being supplied to the combustion burner 51 of the reformer 50 together with the air 56 and combusting. In addition, natural gas 42 is supplied to the combustion burner 54 of the boiler 53 together with air 67 in order to produce steam necessary for generating hydrogen by performing a steam reforming reaction of hydrocarbons in the reformer 50 and burning. Let As a result, the combustion burner exhaust gas 69 from the combustion burner 51 of the reformer 50 and the combustion burner exhaust gas 70 from the combustion burner 54 of the boiler 53 are generated by the combustion of the hydrogen purifier exhaust gas 29 and the natural gas 42. In addition to carbon dioxide and water vapor, a large amount of nitrogen in the air will be included, and for the separation and recovery of carbon dioxide, a global warming gas, an expensive and large-scale carbon dioxide separation and recovery device is required. It becomes. For example, a carbon dioxide absorption / release device filled with a gas absorption / release agent such as a lithium compound having the property of absorbing carbon dioxide at a predetermined temperature and releasing the absorbed carbon dioxide at a predetermined high temperature. It is possible to recover the carbon dioxide in the combustion burner exhaust gas 69, 70 by supplying the combustion burner exhaust gas 69, 70 to the combustion chamber. There is a problem that it is necessary to newly install a carbon dioxide absorption / release device to perform continuous absorption / release of carbon dioxide, resulting in an increase in system cost. In addition, there is a problem that the maintenance cost increases due to replacement of the gas absorption / release agent, and the carbon dioxide absorption / release device causes absorption / release of carbon dioxide depending on the temperature, resulting in an increase in energy consumption. .

Further, the fuel reformer outlet gas 63 discharged from the fuel reformer 59 is a hydrogen-rich reformed gas generated from natural gas and having a reduced carbon monoxide concentration, but the hydrogen concentration in this gas is Since it is as low as about 70% by volume, a process in the hydrogen purifier 25 is necessary to produce the high purity hydrogen 26, and there is a problem that the loss of hydrogen in the hydrogen purifier 25 and the energy loss for hydrogen purification are large. There is also a point.
Ryuichi Hirotani, “Off-site hydrogen supply station”, Clean Energy, Vol. 13, No. 8, pages 25-29 (2004), Nihon Kogyo Publishing Akihiko Hashimoto, “Liquid Hydrogen Storage Hydrogen Station”, Clean Energy, Vol. 13, No. 8, pp. 30-34 (2004), Nihon Kogyo Publishing Masayuki Hattori, “Desulfurized Gasoline Reforming Hydrogen Station”, Clean Energy, Vol. 13, No. 8, pp. 20-24 (2004), Nihon Kogyo Publishing Hiroki Yoshida, “Senju Hydrogen Station”, Clean Energy, Vol. 13, No. 9, pp. 22-26 (2004), Nihon Kogyo Publishing Tetsuya Mori et al., “Natural Gas Reforming Hydrogen Station (WE-NET)”, Clean Energy, Vol. 13, No. 9, pp. 27-31 (2004), Nihon Kogyo Publishing Takeshi Manabe, “Methanol reforming hydrogen station”, Clean Energy, Vol. 13, No. 9, pp. 32-36 (2004), Nihon Kogyo Publishing Masaki Ikematsu, “Naphtha reforming hydrogen supply station”, Clean Energy, Vol. 13, No. 9, pp. 37-40 (2004), Nihon Kogyo Publishing

  As described above, the hydrogen supply system that produces hydrogen by reforming hydrocarbon fuels such as gasoline, liquefied petroleum gas, natural gas, methanol, naphtha, or alcohol fuels has a purity of hydrogen obtained by reforming. Are not high, and there are problems that it is difficult to efficiently perform hydrogen production, hydrogen recovery, and carbon dioxide recovery.

  Then, the objective of this invention is providing the electrolytic cell which can produce | generate high purity hydrogen from a water-soluble organic compound and water.

  Another object of the present invention is to provide a hydrogen supply system that can obtain high-purity hydrogen from a water-soluble organic compound and water, and that can efficiently perform hydrogen production, hydrogen recovery, and carbon dioxide recovery. It is to provide.

  The electrolytic cell of the present invention is an electrolytic cell that performs electrolysis of an aqueous solution of a water-soluble organic compound, and is disposed in an anode chamber to which an aqueous solution is supplied; and an anode chamber, and carbon dioxide, protons, An anode having an electrocatalyst effective for generating electrons, an electrolyte membrane having proton conductivity disposed adjacent to the anode, and a proton disposed adjacent to the electrolyte membrane and generated at the anode; A cathode having an electrocatalyst effective to generate hydrogen by an electrochemical reaction with electrons, hydrogen selective permeation means for selectively permeating hydrogen generated at a cathode disposed adjacent to the cathode, A hydrogen selective permeation means is disposed, and a cathode chamber to which hydrogen permeated through the hydrogen selective permeation means is supplied.

  In the electrolytic cell of the present invention, as the hydrogen selective permeation means, for example, a palladium film or a polymer film that can selectively permeate only hydrogen molecules is used.

  The first hydrogen supply system of the present invention is a hydrogen supply system for producing and supplying hydrogen from a water-soluble organic compound and water, and a fuel storage means for storing an aqueous solution of the water-soluble organic compound; An electrolytic cell having an electrolysis cell, electrolyzing an aqueous solution supplied from a fuel storage unit to separate and produce hydrogen and carbon dioxide, and collecting carbon dioxide separated and produced by the electrolytic unit, Carbon dioxide recovery means for supplying to the storage means, hydrogen recovery means for recovering the hydrogen separated and generated by the electrolysis means, hydrogen supply means for supplying the hydrogen recovered by the hydrogen recovery means to a hydrogen supply destination, Have

  A second hydrogen supply system of the present invention is a hydrogen supply system that produces and supplies hydrogen from a water-soluble organic compound and water, and has the above-described electrolysis cell of the present invention. Electrolytic means for separating and producing hydrogen and carbon dioxide by decomposition, carbon dioxide collecting means for collecting the carbon dioxide produced by separating by the electrolytic means, and carbon dioxide collected by the carbon dioxide collecting means for carbon dioxide Carbon dioxide supply means for supplying to the supply destination, hydrogen recovery means for recovering the hydrogen separated and generated by the electrolysis means, and hydrogen supply means for supplying the hydrogen recovered by the hydrogen recovery means to the hydrogen supply destination It is characterized by having.

  In the hydrogen supply system of the present invention, the hydrogen supply destination is typically a device that consumes hydrogen, such as a hydrogen fuel cell vehicle, various portable devices having a fuel cell using hydrogen as a fuel, and hydrogen. Is a cogeneration system that uses fuel as fuel. The carbon dioxide supply destination is, for example, various types of carbon dioxide processing apparatuses. Among such carbon dioxide processing apparatuses, there is an apparatus that processes the carbon dioxide without releasing carbon dioxide into the environment. Is also included.

  The hydrogen supply system of the present invention may be provided with a hydrogen pressurizing unit that pressurizes hydrogen recovered by the hydrogen recovery unit, a hydrogen storage unit that stores hydrogen pressurized by the hydrogen pressurizing unit, Hydrogen storage means for storing hydrogen recovered by the hydrogen recovery means may be provided.

  In the hydrogen supply system of the present invention, a carbon dioxide pressurizing unit that pressurizes the carbon dioxide recovered by the carbon dioxide recovery unit may be provided, and the carbon dioxide that stores the carbon dioxide pressurized by the carbon dioxide pressurizing unit may be provided. Carbon storage means may be provided, and further, carbon dioxide storage means for storing carbon dioxide recovered by the carbon dioxide recovery means may be provided.

  Further, in the hydrogen supply system of the present invention, hydrogen recovered by the hydrogen recovery means and carbon dioxide recovered by the carbon dioxide recovery means are supplied, and oxygen and hydrogen contained in the supplied carbon dioxide are reacted. An oxygen reaction means for generating water or water vapor may be provided. When the oxygen reaction means is provided, a water recovery means for recovering water or water vapor generated by the oxygen reaction means may be provided.

  The water-soluble organic compound used in the present invention is, for example, at least one compound selected from the group consisting of methanol, ethanol, and 2-propanol.

  In the electrolysis cell of the present invention, by providing hydrogen selective permeation means adjacent to the cathode that is the hydrogen generation electrode, it becomes possible to recover high-purity hydrogen from the cathode chamber of the electrolysis cell. It is not necessary to provide a separate hydrogen purifier for obtaining the product.

  In the hydrogen supply system of the present invention, an electrolytic cell (electrolytic means) is electrolyzed with an aqueous solution of a water-soluble organic compound, so that the anode of the electrolysis cell can be produced with less electrolysis power than water electrolysis. The anode chamber outlet gas containing carbon dioxide with a high concentration can be selectively produced by using the above-described electrolysis cell of the present invention, so that high purity hydrogen can be selectively produced from the cathode at the counter electrode. The cathode chamber outlet gas can be generated. Therefore, the hydrogen supply system of the present invention can efficiently produce hydrogen from a water-soluble organic compound and water, recover hydrogen, and recover carbon dioxide, and economically supply hydrogen to hydrogen consuming equipment. It has the advantage of being able to.

  Next, a preferred embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a configuration of a hydrogen supply system according to a first embodiment of the present invention. The hydrogen supply system shown in FIG. 1 performs an electrolysis reaction of the methanol aqueous solution 3 and the fuel storage unit 1 that stores the methanol aqueous solution 3 as a fuel and also stores the recovered carbon dioxide as main components. The electrolysis apparatus 2, the pump 4, the DC power source 11 that outputs a DC current required for the electrolysis reaction of the aqueous methanol solution 3, and the hydrogen recovery apparatus that recovers the hydrogen generated in the electrolysis apparatus 2 as the cathode chamber outlet gas 24 ( In the figure, indicated as “H ₂ recovery” 12, a carbon dioxide recovery apparatus (indicated as “CO ₂ recovery” in the figure) 13 for recovering carbon dioxide generated by the electrolysis apparatus 2 as the anode chamber outlet gas 17, and a flow rate Control valves 21, 22, a hydrogen pressurizer 27 that pressurizes the cathode chamber outlet gas 24 to produce a pressurized cathode chamber outlet gas 68, and a pressurization cap produced by the hydrogen pressurizer 27. The hydrogen storage unit 28 that stores the sword chamber outlet gas 68, the hydrogen storage unit 40 that stores the cathode chamber outlet gas 24, and the cathode chamber outlet gas stored in the hydrogen storage units 28 and 40 to the hydrogen consuming device 31. Hydrogen supply devices 30 and 41 that supply high purity hydrogen, a carbon dioxide pressurizing device 35 that pressurizes the anode chamber outlet gas 17 recovered by the carbon dioxide recovery device 13 to produce a pressurized anode chamber outlet gas 37, oxygen A reaction device 72 and a water recovery device 73 for recovering water or water vapor from the effluent or exhaust gas of the oxygen reaction device 72 are provided. The hydrogen supply system shown in FIG. 1 differs from the conventional hydrogen supply system shown in FIG. 6 in that the hydrogen purifier 25 is unnecessary, and the fuel storage unit 1, the electrolyzer 2, and the hydrogen recovery instead of the fuel reformer 59. The apparatus 12 and the carbon dioxide recovery device 13 are provided, and the difference is that a carbon dioxide pressurizing device 35, an oxygen reaction device 72, and a water recovery device 73 are newly provided.

  When the fuel storage unit 1 uses this hydrogen supply system to supply hydrogen to a hydrogen consuming device other than a portable device, the fuel storage unit 1 replaces the methanol aqueous solution 3 that is one of the aqueous solutions of water-soluble organic compounds. A possible tank. When this hydrogen supply system is used to supply hydrogen to a portable device, the fuel storage unit 1 is an easily replaceable cartridge that stores the aqueous methanol solution 3. Instead of the aqueous methanol solution 3, an aqueous ethanol solution, an aqueous 2-propanol solution or the like may be used as an aqueous solution of the water-soluble organic compound. As will be described later, the molar ratio of methanol and water in the aqueous methanol solution 3 is preferably 1: 1 because methanol and water are reacted in an equimolar amount to generate hydrogen, but is not necessarily limited to 1: 1. is not.

The aqueous methanol solution 3 stored in the fuel storage unit 1 is supplied by a pump 4 to the anode chamber 5 of the electrolysis cell 10 constituting the electrolysis apparatus 2. The configuration of the electrolysis cell 10 is shown in FIG. The electrolysis cell 10 is based on the present invention, and includes an anode 6, an anode chamber 5 including the anode 6, an electrolyte membrane 7, a cathode 8, a hydrogen selective permeation unit 18, and a cathode chamber 9. ing. The cathode 8 and the hydrogen selective permeation unit 18 are disposed in the cathode chamber 9. The electrolyte membrane 7 separates the anode chamber 5 and the cathode chamber 9, and the anode 6 and the cathode 8 are provided in contact with the electrolyte membrane 7 so as to sandwich the electrolyte membrane 7. An electrode catalyst effective for generating carbon dioxide (CO ₂ ), protons (H ⁺ ), and electrons (e ⁻ ) by an electrochemical reaction of the aqueous methanol solution 3 is deposited on the surface of the anode 6. Similarly, an electrode catalyst effective to generate hydrogen (H ₂ ) by an electrochemical reaction between protons and electrons generated at the anode 6 is deposited on the surface of the cathode 8. Hydrogen ions (protons) generated at the anode 6 move through the electrolyte membrane 7 and reach the cathode 8.

  The hydrogen selective permeation unit 18 has a property of selectively permeating hydrogen generated at the cathode 8 and is composed of, for example, a hydrogen separation membrane represented by a palladium membrane. Instead of the palladium membrane, a polymer membrane having a property of selectively permeating hydrogen can also be used. Such a hydrogen selective permeation part 18 is typically provided on the surface of the cathode 8 on the cathode chamber 6 side as a membrane-like member, whereby only hydrogen permeates the hydrogen selective permeation part 18 from the cathode 8. Then, it is supplied to the cathode chamber 6.

  In FIG. 2, the electrolysis apparatus 2 is constituted by a set of electrolysis cells 10, but is not necessarily limited to one set, and the electrolysis apparatus 2 may be constituted by a plurality of sets of electrolysis cells 10. .

The DC power supply 11 is supplied with electric power 14 obtained from a predetermined energy source such as a private power generator such as a solar cell, a wind power generator, a fuel cell, a gas engine, a diesel engine, or a gas turbine, or a commercial power source. The electric power 14 supplied to the DC power supply 11 is subjected to predetermined conversion by the DC power supply 11, supplied to the electrolysis cell 10 in the form of DC power 15, and the electricity of the aqueous methanol solution 3 supplied to the anode chamber 5 of the electrolysis cell 10. Used for disassembly. That is, an electrolysis voltage is applied between the anode 6 and the cathode 8 of the electrolysis cell 10 by the DC power 15 supplied from the DC power source 11 to the electrolysis cell 10, and an electrolysis current flows, thereby electrolyzing the aqueous methanol solution 3. Happens. At the anode 6, an electrochemical reaction of methanol (CH ₃ OH) and water (H ₂ O) shown in the formula (3) occurs, and carbon dioxide (CO ₂ ), protons (H ⁺ ), and electrons (e ⁻ ) are generated. .

CH ₃ OH + H ₂ O → CO ₂ + 6H ⁺ + 6e ⁻ (3)
A catalyst is required to advance the electrochemical reaction of methanol and water at the anode 6, and a platinum catalyst or a platinum-ruthenium alloy catalyst in which platinum or a platinum-ruthenium alloy is supported on a carbon support or the like is generally used. ing. As described above, this catalyst is deposited on the surface of the anode 6 as an electrode catalyst. Protons generated at the anode 6 by the electrochemical reaction of methanol and water shown in the formula (3) move through the electrolyte membrane 7 having proton conductivity and reach the cathode 8 in the cathode chamber 9. For the electrolyte membrane 7 having proton conductivity, a perfluorosulfonic acid membrane having a sulfonic acid group and having high gas tightness is generally used. Further, the electrons generated at the anode 6 by the electrochemical reaction of methanol and water shown in the equation (3) move through the external circuit including the DC power supply 11 and reach the cathode 8. At the cathode 8, as shown in the equation (4), an electrochemical reaction occurs between protons moving from the anode 6 in the electrolyte membrane 7 and electrons moving from the anode 6 in the external circuit, and hydrogen is generated.

_{^{6H + + 6e - → 3H 2}} (4)
In addition, a catalyst is also required to advance the electrochemical reaction represented by the formula (4) at the cathode, and a platinum catalyst or a platinum-ruthenium alloy catalyst in which platinum or a platinum-ruthenium alloy is supported on a carbon carrier or the like is generally used. It is used. As described above, this catalyst is deposited on the surface of the cathode 8 as an electrode catalyst.

  The electrolysis reaction of the aqueous methanol solution 3 as a whole is a combination of the reaction at the anode 6 shown in the formula (3) and the reaction at the cathode 8 shown in the formula (4). As shown in the above, methanol and water react to produce carbon dioxide and hydrogen.

CH ₃ OH + H ₂ O → CO ₂ + 3H ₂ (5)
As described above, carbon dioxide is generated at the anode 6 of the electrolysis cell 10 of the electrolysis apparatus 2, and hydrogen is generated at the cathode 8. The carbon dioxide generated at the anode 6 is separated from the unreacted aqueous methanol solution 16 and recovered as the anode chamber outlet gas 17 in the carbon dioxide recovery device 13 provided adjacent to the anode chamber 5. On the other hand, the hydrogen generated at the cathode 8 permeates the hydrogen selective permeation section 18 such as a hydrogen separation membrane represented by a palladium membrane and reaches the cathode chamber 9, and as shown in FIG. It is recovered as cathode outlet gas 24. By providing the hydrogen selective permeation section 18 adjacent to the cathode of the electrolytic cell 10, the permeation of the methanol aqueous solution 3 from the anode 6 to the cathode 8 through the electrolyte membrane 7, and the anode 6 as shown in the formula (3) Permeation of carbon dioxide generated by the electrochemical reaction is suppressed. Therefore, in this hydrogen supply system, high-purity hydrogen can be recovered from the electrolysis apparatus 2 as the cathode chamber outlet gas 24, and it is not necessary to provide a separate hydrogen purification apparatus. Further, since there is no permeation of the methanol aqueous solution 3 to the cathode chamber 9, it is not necessary to recycle the methanol aqueous solution permeated to the cathode chamber 9 to the anode chamber 6 or the fuel storage unit 1.

  The methanol concentration of the unreacted aqueous methanol solution 16 separated from the anode chamber outlet gas 17 by the carbon dioxide recovery device 13 is substantially equal to the methanol concentration of the aqueous methanol solution 3 supplied to the anode chamber 5 of the electrolysis cell 10. The aqueous solution 16 is recycled to the fuel storage unit 1 or the anode chamber 5 of the electrolysis cell 10 as necessary using the pump 4. The outlet for discharging the unreacted methanol aqueous solution 16 of the carbon dioxide recovery device 13 is branched into two branches, one leading to the fuel storage unit 1 via the flow control valve 21 and the other via the flow control valve 22 to the pump 4 and the electrolyzer. 2 is connected to the supply line connecting the two. Therefore, the recycle amounts of the unreacted aqueous methanol solution 16 separated by the carbon dioxide recovery device 13 to the fuel storage unit 1 and the anode chamber 5 are controlled by adjusting the opening degree of the flow control valves 21 and 22, respectively. .

  The cathode chamber outlet gas 24 made of high-purity hydrogen is supplied to the hydrogen pressurizing device 27 and pressurized as necessary, and then supplied as a pressurized cathode chamber outlet gas 68 to the hydrogen storage unit 28 such as a high-pressure tank. Stored. The pressurized cathode chamber outlet gas 68 stored in the hydrogen storage unit 28 is converted into high-purity hydrogen by using a hydrogen supply device 30, as necessary, as a hydrogen fuel cell automobile, a residential fuel cell cogeneration system for a detached house. The fuel cell cogeneration system for households in apartment houses, the fuel cell cogeneration system for commercial use in shops and factories, and the hydrogen consuming equipment 31 such as portable devices. In the hydrogen supply device 30, the pressurized cathode chamber outlet gas 68 is depressurized according to the rating of the hydrogen consuming equipment 31.

  The cathode chamber outlet gas 24 made of high-purity hydrogen may be stored as it is in a hydrogen storage unit 40 such as a hydrogen storage alloy tank at normal pressure. Also in this case, the cathode outlet gas 24 stored in the hydrogen storage unit 40 is converted into high-purity hydrogen by using a hydrogen supply device 41, as necessary, as a hydrogen fuel cell vehicle, a residential fuel cell cogeneration system for a detached house. Hydrogen fuel consumption equipment 31 such as a system, a fuel cell cogeneration system for residential use in an apartment house, a fuel cell cogeneration system for commercial use in shops and factories, and portable equipment. Note that the hydrogen supply device 30 pressurizes the cathode chamber outlet gas in accordance with the rating of the hydrogen consuming device 31 and the like.

  The carbon dioxide concentration of the anode chamber outlet gas 17 containing carbon dioxide generated at the anode 6 of the electrolysis cell 10 of the electrolysis device 2 is as high as 90% by volume or more. Therefore, in the hydrogen supply system of this embodiment, it is not necessary to newly provide a carbon dioxide absorption / release device that absorbs and releases carbon dioxide in order to separate and recover carbon dioxide, and energy is used to separate and recover carbon dioxide. There is no need to consume. By recovering the anode chamber outlet gas 17 as it is, it is possible to efficiently recover carbon dioxide.

In addition, in the anode 6 of the electrolysis cell 10 of the electrolysis apparatus 2, in addition to the electrochemical reaction of methanol and water shown in the formula (3), an electrolysis reaction of water shown in the formula (6) also occurs. The anode chamber outlet gas 17 recovered in 13 may contain some oxygen (O ₂ ).

H ₂ O → (1/2) O ₂ + 2H ⁺ + 2e ⁻ (6)
Therefore, in the present embodiment, an oxygen reaction device 72 such as a catalytic combustor using a noble metal catalyst such as platinum is provided, and the anode outlet gas 17 and the cathode chamber outlet gas 24 containing high-concentration hydrogen are provided in the oxygen reaction device 72. Then, oxygen in the anode chamber outlet gas 17 and hydrogen in the cathode chamber outlet gas 24 are combusted by a combustion reaction represented by the formula (7) to generate water or water vapor, and oxygen in the anode chamber outlet gas 17 is Remove.

(1/2) O ₂ + H ₂ → H ₂ O (7)
The water or water vapor generated by the oxygen reaction device 72 is collected by providing a water collecting device 73 such as a condenser or a water adsorber (filled with silica gel or the like) as necessary. The anode chamber outlet gas 17 from which water or water vapor has been recovered by the moisture recovery device 73 is pressurized by the carbon dioxide pressurizing device 35 as necessary, and then supplied to the fuel storage unit 1 as the pressurized anode chamber outlet gas 37. Stored. The pressurized anode chamber outlet gas 37 stored in the fuel storage unit 1 and containing high-concentration carbon dioxide is replaced by replacing the fuel storage unit 1 with the methanol aqueous solution 3 stored in the fuel storage unit 1. It can be recovered. Since the anode chamber outlet gas 17 can be pressurized to about several atmospheres (several hundred kPa) by the electrolysis apparatus 2, carbon dioxide is directly supplied without pressurizing the anode chamber outlet gas 17 by providing a carbon dioxide pressurizing device 35. It is also possible to supply the anode chamber outlet gas 17 to the fuel storage unit 1.

  Since carbon dioxide is an inert gas, there is no danger even if it is stored in the gas phase portion of the fuel storage unit 1 that stores the aqueous methanol solution 3. Since the fuel storage unit 1 is in a depressurized state as the methanol aqueous solution 3 is consumed, if the carbon dioxide, that is, the anode chamber outlet gas 17 is supplied to the fuel storage unit 1, the depressurization can be suppressed. There is also an advantage that the electrolytic device 2 can be smoothly supplied.

  In the hydrogen supply system of the first embodiment shown in FIG. 1, the hydrogen pressurization device 27, the hydrogen storage units 28 and 40, the oxygen reaction device 72, the moisture recovery device 73, and the carbon dioxide pressurization device 35 are described. Some or all of these are not necessarily provided, and may be provided as appropriate in accordance with the purpose of use of the hydrogen supply system.

  In the hydrogen supply system of the present embodiment, high-purity hydrogen can be recovered as the cathode chamber outlet gas 24 by the hydrogen recovery device 12 adjacent to the cathode chamber 9 of the electrolysis cell 10 of the electrolysis device 2, so it is necessary to provide a hydrogen purification device. The system cost and energy cost can be reduced. Further, in the hydrogen supply system of the present embodiment, high concentration carbon dioxide having a carbon dioxide concentration of 90% by volume or more is discharged from the anode chamber outlet gas by the carbon dioxide recovery device 13 adjacent to the anode chamber 5 of the electrolysis cell 10 of the electrolysis device 2. The carbon dioxide absorption / release device for absorbing and releasing carbon dioxide for separating and recovering carbon dioxide is not necessary. Further, in the hydrogen supply system of the present embodiment, it is not necessary to provide a storage tank for storing only carbon dioxide, and the recovered carbon dioxide is stored in the fuel storage unit 1 that stores an aqueous methanol solution as fuel. By exchanging the fuel storage unit 1, fuel supply and carbon dioxide recovery can be easily performed simultaneously. Therefore, according to the present embodiment, the system cost necessary for installing the carbon dioxide absorption / release device and the running cost such as the maintenance cost and the energy cost can be reduced, and the tank for storing only carbon dioxide is installed. Therefore, it is possible to reduce the system cost required for this, and it is possible to realize a hydrogen supply system capable of recovering carbon dioxide economically.

In the hydrogen supply system of the present embodiment, in order to electrolyze the aqueous methanol solution 3 by the electrolytic cell 10 in the electrolysis apparatus 2, the power 14 obtained from a predetermined energy source is converted into the predetermined DC power 15 by the DC power source 11. Although it is necessary to convert and supply to the electrolytic cell 10, as shown in FIG. 3, the electrolysis voltage of the aqueous methanol solution is 30 to 42% of the electrolysis voltage of water. Since the electrolysis power is determined by the electrolysis voltage, considering the electrolysis power necessary for obtaining the same number of moles of hydrogen, the electrolysis power in the case of electrolysis of aqueous methanol solution is 30 to 42%. Therefore, the hydrogen supply system of this embodiment does not cause an increase in energy cost accompanying an increase in energy consumption, as compared with a hydrogen supply system using conventional water electrolysis. 3 shows a platinum-ruthenium catalyst (electrolysis of aqueous methanol solution 3) or platinum catalyst (electrolysis of water) as a catalyst for the anode 6 of the electrolytic cell 10, a platinum catalyst as a catalyst for the cathode 8, and the electrolyte membrane 7. 2 shows the relationship between the electrolysis voltage and electrolysis current when electrolysis of aqueous methanol solution and electrolysis of water are performed using perfluorosulfonic acid membranes respectively. The concentration of the aqueous methanol solution supplied to the anode chamber 5 of the electrolysis cell 10 was 17 mol / l (molar ratio of methanol to water was 1: 1), and the supply amount of the aqueous methanol solution 3 was 5 ml / min. The effective electrode surface areas of the anode 6 and the cathode 8 of the electrolytic cell 10 were 23 cm ² , respectively. Note that the electrolysis voltage of the aqueous methanol solution was reduced to 30 to 42% compared to the electrolysis voltage of water. However, as shown in FIG. It was confirmed that hydrogen was produced at the theoretical production rate.

  Next, a hydrogen supply system according to a second embodiment of the present invention will be described. The hydrogen supply system according to the second embodiment shown in FIG. 5 has, as main components, the fuel storage unit 1, the electrolyzer 2, the pump 4, the DC power source 11, as in the first embodiment. Hydrogen recovery device 12, carbon dioxide recovery device 13, flow rate control valves 21, 22, hydrogen pressurization device 27, hydrogen storage units 28, 40, hydrogen supply devices 30, 41, carbon dioxide pressurization device 35, oxygen reaction device 72, In addition, a carbon dioxide storage unit 36 and a carbon dioxide supply device 38 are provided. In this hydrogen supply system, the pressurized anode chamber outlet gas 37 pressurized by the carbon dioxide pressurizing device 35 and containing carbon dioxide as a main component is not returned to the fuel storage unit 1, but is supplied to the carbon dioxide storage unit 36. To be supplied. The carbon dioxide supply device 38 is provided in contact with the carbon dioxide storage unit 36 and supplies the carbon dioxide stored in the carbon dioxide storage unit 36 toward the carbon dioxide processing device 39. In FIG. 5, the same components as those in FIG. 1 described above are denoted by the same reference numerals, and duplicate descriptions thereof are omitted. The carbon dioxide processing device 39 is, for example, a device that collects and processes carbon dioxide without releasing it into the environment.

  In the hydrogen supply system of the present embodiment, the anode chamber outlet gas 17 separated from the unreacted methanol aqueous solution 16 by the carbon dioxide recovery device 13 is supplied to the oxygen reactor 72, and in the oxygen reactor 72, the anode chamber outlet gas 17 is supplied. Is converted into water or water vapor. Water or water vapor generated by the oxygen reaction device 72 is recovered by the water recovery device 73 as necessary. The anode chamber outlet gas 17 from which water or water vapor has been recovered by the moisture recovery device 73 is pressurized by the carbon dioxide pressurizing device 35 as necessary, and then supplied to the carbon dioxide storage unit 36 as the pressurized anode chamber outlet gas 37. Stored. The pressurized anode chamber outlet gas 37 stored in the carbon dioxide storage unit 36 is decompressed by the carbon dioxide supply device 38 as necessary and supplied to the carbon dioxide processing device 39. In addition, the carbon dioxide storage part 36 and the carbon dioxide pressurizing apparatus 35 are not necessarily required, and are provided as needed. For example, the oxygen gas contained in the anode chamber outlet gas 17 is converted into water or water vapor by the oxygen reaction device 72 and the water recovery device 72 collects the water or water vapor as necessary. The carbon dioxide processing device 39 may be supplied as it is.

  In the hydrogen supply system of the second embodiment shown in FIG. 5, the hydrogen pressurizing device 27, the hydrogen storage units 28 and 40, the oxygen reaction device 72, and the moisture recovery device 73 are also part or all of them. Are not necessarily provided, and may be appropriately provided in accordance with the purpose of use of the hydrogen supply system.

  Also in the hydrogen supply system of the present embodiment, high-purity hydrogen can be recovered as the cathode chamber outlet gas 24 by the hydrogen recovery device 12 adjacent to the cathode chamber 9 of the electrolysis cell 10 of the electrolysis device 2, so it is necessary to provide a hydrogen purification device The system cost and energy cost can be reduced. Further, since the carbon dioxide recovery device 13 adjacent to the anode chamber 5 of the electrolysis cell 10 of the electrolysis device 2 can recover high-concentration carbon dioxide having a carbon dioxide concentration of 90% by volume or more as the anode chamber outlet gas 17, A carbon dioxide absorption / release device that absorbs and releases carbon dioxide for separation / recovery is not necessary, and system costs necessary for installing the carbon dioxide absorption / release device, etc., and running costs such as maintenance costs and energy costs can be reduced. . Therefore, according to the present embodiment, the system cost necessary for installing the carbon dioxide absorption / release device, the running cost such as the maintenance cost, and the energy cost can be reduced, and the hydrogen supply capable of recovering carbon dioxide economically. A system can be realized.

  As described above, the electrolysis cell and the hydrogen supply system according to the preferred embodiment of the present invention have been described. However, in the electrolysis cell and the hydrogen supply system according to the present invention, as the fuel for generating hydrogen, instead of the methanol aqueous solution, other An aqueous solution of an aqueous organic compound can also be used. The water-soluble organic compound used in the present invention is not particularly limited as long as it is a water-soluble organic compound, but among them, an organic compound that dissolves in an arbitrary ratio with respect to water is preferable. Also preferred are organic compounds whose constituent elements are hydrogen, carbon, and optionally oxygen. Specific examples of water-soluble organic compounds that can be used in the present invention include water-soluble alcohols, organic acids, ketones, amines, nitroalkanes, ethers (including cyclic ethers), aldehydes, or derivatives thereof. Can be mentioned. Alcohols, organic acids, ketones, amines, nitroalkanes, ethers, and aldehydes preferably have about 1 to 20 carbon atoms. The cyclic ether preferably has a 4- to 6-membered ring skeleton, and the number of carbon atoms in the cyclic ether is preferably about 5 to 10.

  Examples of the water-soluble alcohol include methanol, ethanol, normal propanol, isobropanol (2-propanol), normal butanol, isobutanol, sec-butanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 1-hexanol, 2-hexanol, 3-hexanol, 5-methyl-1-hexanol, isoamyl alcohol (3-methyl-1-butanol), sec-isoamyl alcohol (3-methyl- 2-butanol), isoundecylene alcohol, isooctanol, isopentanol, isogeranol, isohexanol, 2,4-dimethyl-1-pentanol, 2,4,4-trimethyl-1-pentanol, etc. Monovalent alcohol with 1-20 atoms , Dihydric alcohols such as ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,2-propanediol, 1,2-pentanediol, or butanetriol, glycerin, di Examples thereof include polyhydric alcohols having 3 to 10 carbon atoms such as glycerin.

  Examples of the water-soluble organic acid include acetic acid and propionic acid. Examples of the water-soluble ketone include acetone, methyl ethyl ketone, cyclohexanone, cyclooctanone, cyclodecanone, and isophorone. Examples of the water-soluble amine include methylamine and ethylamine. Examples of the nitroalkane having water solubility include nitroethane. Examples of the water-soluble ether include dimethyl ether, diethyl ether, polyoxyethylene phenyl ether, polyoxyethylene octyl phenyl ether, and the like. Examples of the water-soluble cyclic ether include tetrahydrofuran, 1,4-dioxane, 1,3-dioxane and the like. Examples of the water-soluble aldehyde include formaldehyde and acetaldehyde.

  Other water-soluble organic compounds that can be used in the present invention include esters such as ethyl acetate, ethylene glycol alkyl ethers such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve, and acetates thereof, ethyl carbitol, butyl carbitol, and the like. Diethylene glycol alkyl ethers and acetates thereof, propylene glycol alkyl ethers and acetates thereof, monohydric alcohols having 4 to 30 carbon atoms, phenolic compounds having 6 to 30 carbon atoms, alkylene having 6 to 30 carbon atoms An active hydrogen-containing compound composed of a polyamine having 2 to 6 carbon atoms (2 to 4 nitrogen atoms) such as glycol, polyhydric alcohol having 6 to 30 carbon atoms, ethylenediamine, diethylenepolyamine, etc. Water-soluble liquid alkylene oxide adducts with added pyrene oxide (1 to 10 moles of ethylene oxide), water-soluble polymers such as polyvinyl alcohol, various sugars such as saccharose and glucose, water-soluble polymers such as methyl cellulose and water-soluble starch Examples thereof include saccharides or derivatives thereof.

  Especially, as a water-soluble organic compound used by this invention, a C3-C10 polyhydric alcohol, a C1-C20 monohydric alcohol, and a C3-C20 ketone are preferable, Furthermore, Alcohols such as methanol, ethanol and 2-propanol are more preferable. As the water-soluble organic compound used in the present invention, only one kind of compound as described above may be used alone, or two or more kinds of compounds as described above may be used in combination. In the present invention, the aqueous solution of the water-soluble organic compound may contain other components as long as it contains the water-soluble organic compound as described above.

  It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications are made without departing from the spirit of the present invention.

It is a figure which shows the structure of the hydrogen supply system of the 1st Embodiment of this invention. It is a figure which shows the structure of the electrolysis cell which is one Embodiment of this invention. It is a graph which shows the relationship between the electrolysis voltage and the electrolysis current in the electrolysis of methanol aqueous solution and the electrolysis of water. It is a graph which shows the relationship between the hydrogen production | generation rate and electrolysis current in the electrolysis of methanol aqueous solution. It is a figure which shows the structure of the hydrogen supply system of the 2nd Embodiment of this invention. It is a figure which shows the structure of the conventional hydrogen supply system which uses natural gas as a fuel.

Explanation of symbols

1 fuel reservoir 2 electrolysis device 3 methanol solution 4,48 pump 5 the anode chamber 6 anode 7 electrolyte membrane 8 cathode 9 cathode compartment 10 electrolytic cell 11 DC power supply 12 hydrogen recovery device (H ₂ recovery)
13 Carbon dioxide recovery device (CO ₂ recovery)
14 Electric power 15 DC power 16 Unreacted methanol aqueous solution 17 Anode chamber outlet gas 18 Hydrogen selective permeation part 21, 22, 43 to 46, 57, 65 Flow control valve 24 Cathode chamber outlet gas 25 Hydrogen purifier 26 High purity hydrogen 27 Hydrogenation Pressure device 28, 40 Hydrogen storage unit 29 Hydrogen purifier exhaust gas 30, 41 Hydrogen supply device 31 Hydrogen consuming equipment 35 Carbon dioxide pressurizing device 36 Carbon dioxide storage unit 37 Pressurized anode chamber outlet gas 38 Carbon dioxide supply device 39 Carbon dioxide Processing unit 42 Natural gas 47, 58 Blower 49 Desulfurizer 50 Reformer 51, 54 Combustion burner 52 CO converter 53 Boiler 55 Make-up water 56, 67 Air 59 Fuel reformer 60 Reformer outlet gas 61 Steam 62 Sulfur component Gas from which gas was removed 63 Fuel reformer outlet gas 64 CO converter Outlet gas 66 Desulfurizer recycle gas 68 Pressurized cathode chamber outlet gas 69, 70 Combustion burner exhaust gas 71 Pressurized high purity hydrogen 72 Oxygen reactor 73 Moisture recovery device

Claims (13)

In an electrolysis cell for electrolysis of an aqueous solution of a water-soluble organic compound,
An anode chamber to which the aqueous solution is supplied;
An anode having an electrocatalyst disposed in the anode chamber and effective to generate carbon dioxide, protons, and electrons by an electrochemical reaction of the aqueous solution;
An electrolyte membrane having proton conductivity disposed adjacent to the anode;
A cathode having an electrocatalyst disposed adjacent to the electrolyte membrane and effective for generating hydrogen by an electrochemical reaction between protons generated at the anode and the electrons;
Hydrogen selective permeation means for selectively permeating hydrogen generated at the cathode disposed adjacent to the cathode;
A cathode chamber in which the cathode and the hydrogen selective permeation means are arranged, and the hydrogen that has permeated the hydrogen selective permeation means is supplied;
An electrolysis cell comprising:   The electrolytic cell according to claim 1, wherein the water-soluble organic compound is at least one compound selected from the group consisting of methanol, ethanol, and 2-propanol. In a hydrogen supply system that produces and supplies hydrogen from a water-soluble organic compound and water,
Fuel storage means for storing an aqueous solution of the water-soluble organic compound;
An electrolysis unit comprising the electrolysis cell according to claim 1, and electrolyzing the aqueous solution supplied from the fuel storage unit to generate hydrogen and carbon dioxide separately.
Carbon dioxide recovery means for recovering the carbon dioxide separated and produced by the electrolysis means and supplying the fuel storage means;
Hydrogen recovery means for recovering the hydrogen separated and generated by the electrolysis means;
Hydrogen supply means for supplying the hydrogen recovered by the hydrogen recovery means to a hydrogen supply destination;
A hydrogen supply system comprising: In a hydrogen supply system that produces and supplies hydrogen from a water-soluble organic compound and water,
An electrolysis unit comprising the electrolysis cell according to claim 1, wherein the aqueous solution of the water-soluble organic compound is electrolyzed to separate and generate hydrogen and carbon dioxide;
Carbon dioxide recovery means for recovering the carbon dioxide separated and generated by the electrolysis means;
Carbon dioxide supply means for supplying the carbon dioxide recovered by the carbon dioxide recovery means to a carbon dioxide supply destination;
Hydrogen recovery means for recovering the hydrogen separated and generated by the electrolysis means;
Hydrogen supply means for supplying the hydrogen recovered by the hydrogen recovery means to a hydrogen supply destination;
A hydrogen supply system comprising:   The hydrogen supply system according to claim 3, further comprising a hydrogen pressurization unit that pressurizes the hydrogen recovered by the hydrogen recovery unit.   The hydrogen supply system according to claim 5, further comprising a hydrogen storage unit that stores the hydrogen pressurized by the hydrogen pressurization unit.   The hydrogen supply system according to any one of claims 3 to 6, further comprising a hydrogen storage unit that stores the hydrogen recovered by the hydrogen recovery unit.   The hydrogen supply system according to any one of claims 3 to 7, further comprising carbon dioxide pressurizing means for pressurizing the carbon dioxide recovered by the carbon dioxide recovery means.   The hydrogen supply system according to claim 8, further comprising carbon dioxide storage means for storing the carbon dioxide pressurized by the carbon dioxide pressurizing means.   The hydrogen supply system according to any one of claims 3 to 7, further comprising carbon dioxide storage means for storing the carbon dioxide recovered by the carbon dioxide recovery means.   The hydrogen recovered by the hydrogen recovery means and the carbon dioxide recovered by the carbon dioxide recovery means are supplied, and oxygen contained in the supplied carbon dioxide reacts with the hydrogen to produce water or water vapor. The hydrogen supply system according to any one of claims 3 to 10, further comprising oxygen reaction means to be generated.   The hydrogen supply system according to claim 11, further comprising a water recovery unit that recovers the water or water vapor generated by the oxygen reaction unit.   The electrolytic cell according to any one of claims 3 to 12, wherein the water-soluble organic compound is at least one compound selected from the group consisting of methanol, ethanol, and 2-propanol.

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