JP2006144092A - High-pressure hydrogen manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-pressure hydrogen manufacturing device capable of obtaining excellent electrolytic efficiency while no space is generated between a solid polymer electrolyte film and a cathode power supply body by the pressure of gaseous hydrogen generated on a cathode side. <P>SOLUTION: The high-pressure hydrogen manufacturing device comprises a solid polymer electrolyte film 2, at least one single cell 7 comprising a cathode power supply body 3, an anode power supply body 4, a cathode separator 5 and an anode separator 6, and fixing means 14, 15, 16 to fix the solid polymer electrolyte film 2, the power supply bodies 3, 4 and the separators 5, 6 from both sides of the single cell 7. High-pressure gaseous hydrogen is generated on the cathode side by conducting the power supply bodies 3, 4 and performing electrolysis of water to be fed to the anode side. The fixing means 14, 15, 16 are capable of withstanding the pressure stress higher than the pressure of gaseous hydrogen obtained in the single cell 7. Preferably, the fixing means 14, 15, 16 are capable of withstanding the pressure stress higher than the pressure of gaseous hydrogen in a range of 1-40 MPa. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a high-pressure hydrogen production apparatus.

  Conventionally, as shown in FIG. 1, a solid polymer electrolyte membrane 2, a cathode power supply 3 and an anode power supply 4 provided opposite to each other, and cathodes stacked on the power supply bodies 3 and 4, respectively. A high-pressure hydrogen production apparatus 1 including a plurality of single cells 7 each including a separator 5 and an anode separator 6 is known (see, for example, Patent Document 1).

  In the high-pressure hydrogen production apparatus 1, the solid polymer electrolyte membrane 2, the power feeders 3, 4, and the separators 5, 6 are sandwiched between the end plates 14, 14 from both sides of the single cell 7, and the end plate There is known one that is fixed by screwing and tightening a nut 16 to a bolt 15 inserted through 14, 14 (see, for example, Patent Document 2).

  In the high-pressure hydrogen production apparatus 1, for example, the separators 5 and 6 are provided with fluid passages 8 and 10 in which the power feeders 3 and 4 are exposed, and water is supplied to the fluid passage 10 of the anode separator 6. When the cathode power supply body 3 and the anode power supply body 4 are energized, the water supplied to the fluid passage 10 is electrolyzed to generate hydrogen ions and oxygen gas. The generated hydrogen ions permeate the solid polymer electrolyte membrane 2 due to a potential difference, move to the cathode side, and receive electrons from the cathode power supply 3 to generate hydrogen gas. As a result, high-pressure hydrogen gas can be obtained in the fluid passage 8 of the cathode separator 5. On the other hand, oxygen generated in the fluid passage 10 of the anode separator 6 is discharged from a drain port 12 provided in the fluid passage 10 together with the water.

However, in the high-pressure hydrogen production apparatus 1, when oxygen generated on the anode side is discharged as described above, the pressure balance is lost on both sides of the solid polymer electrolyte membrane 2, and as shown in FIG. There is an inconvenience that the solid polymer electrolyte membrane 2 and the anode power feeder 4 are compressed in the direction of the anode separator 6 due to the pressure of the hydrogen generated in the passage 8 to reduce the thickness. When the thickness of the solid polymer electrolyte membrane 2 is reduced, a gap 17 is generated between the solid polymer electrolyte membrane 2 and the cathode power supply 3 to increase the contact resistance between the solid polymer electrolyte membrane 2 and the cathode power supply 3. As a result, the electrolysis efficiency of the high-pressure hydrogen production apparatus 1 decreases.
Special table 2003-515237 gazette JP 2001-348691 A JP 2000-178782 A

  The present invention eliminates such inconvenience, and even if high-pressure hydrogen gas is generated on the cathode side, a gap is not generated between the solid polymer electrolyte membrane and the cathode power feeder due to the pressure of the hydrogen gas, An object of the present invention is to provide a high-pressure hydrogen production apparatus capable of obtaining excellent electrolysis efficiency.

  In order to achieve such an object, the present invention provides a solid polymer electrolyte membrane, a cathode power supply provided opposite to both sides of the solid polymer electrolyte membrane, an anode power supply, and each power supply. And at least one single cell including a stacked cathode separator and an anode separator, and a solid polymer electrolyte membrane, each power feeder, and a fixing means for fixing each separator from both sides of the single cell. In a high-pressure hydrogen production apparatus in which water supplied to the anode side is electrolyzed by energizing the body and high-pressure hydrogen gas is generated on the cathode side, the fixing means is configured to supply hydrogen gas obtained in the single cell. A pressing stress larger than the pressure is provided.

  In the high-pressure hydrogen production apparatus of the present invention, the single cell is fixed in advance by pressing the solid polymer electrolyte membrane, each power feeder, and each separator from both sides thereof by the fixing means. At this time, since the pressing stress of the fixing means is larger than the pressure of the hydrogen gas obtained in the single cell, high-pressure hydrogen gas is generated on the cathode side of the single cell, and the solid gas is generated by the pressure of the hydrogen gas. Even when the polymer electrolyte membrane and the anode feeder are pressed toward the anode plate, the cathode feeder can be further pressed toward the solid polymer electrolyte membrane.

  Therefore, according to the high-pressure hydrogen production apparatus of the present invention, even if high-pressure hydrogen gas is generated on the cathode side of the single cell, the solid polymer electrolyte membrane and the cathode feeder are maintained in contact with each other, An excellent electrolytic efficiency can be obtained without generating a gap between the body and the solid polymer electrolyte membrane.

  In the high-pressure hydrogen production apparatus of the present invention, the number of the single cells may be one, or a plurality of the single cells stacked on each other may be provided.

  The fixing means preferably has a large pressing stress in the range of 1 to 40 MPa, more preferably a large pressing stress in the range of 5 to 20 MPa than the pressure of the hydrogen gas obtained in the single cell. The pressing stress of the fixing means exceeds the pressure of the hydrogen gas obtained in the single cell, and if it is less than 1 MPa, the compression of the solid polymer electrolyte membrane and the anode feeder due to the pressure of the hydrogen gas cannot be sufficiently reduced. There is. Further, if the pressing stress of the fixing means exceeds the pressure of the hydrogen gas obtained in the single cell by more than 40 MPa, the solid polymer film may be damaged.

  In addition, in an electrolysis apparatus in which a pair of power feeding bodies are provided opposite to each other on both sides of a solid polymer electrolyte membrane, a technique for pressing one power feeding body to the other power feeding body side with a predetermined pressure is known. However, the electrolyzer is an apparatus for producing sodium hydroxide and chlorine, and although hydrogen is produced as a by-product, it does not become a high pressure. Therefore, the pressure is larger than the pressure of the hydrogen gas obtained in the single cell. There is no suggestion of pressing with stress (see Patent Document 3).

  Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. FIG. 1 is an explanatory cross-sectional view showing the configuration of the high-pressure hydrogen production apparatus of the present embodiment, and FIG. 2 is a graph showing the relationship between the pressure of the generated hydrogen gas and the electrolysis voltage in the high-pressure hydrogen production apparatus of the present embodiment. is there.

  As shown in FIG. 1, the high-pressure hydrogen production apparatus 1 of the present embodiment includes a solid polymer electrolyte membrane 2, a cathode power supply 3, an anode power supply 4 provided opposite to each other, and each power supply. Two unit cells 7 each including a cathode separator 5 and an anode separator 6 stacked on 3 and 4 are stacked. In the single cells 7 and 7, the anode separator 6 of the other single cell 7 is laminated on the cathode separator 5 of the single cell 7.

  In each single cell 7, the cathode separator 5 includes a fluid passage 8 in which the cathode power supply 3 is exposed and a hydrogen outlet 9 communicating with the fluid passage 8, and the anode separator 6 is a fluid in which the anode power supply 4 is exposed. A passage 10, a water supply port 11 that communicates with one end of the fluid passage 10, and a drain port 12 that communicates with the other end of the fluid passage 10 are provided.

  The power feeders 3 and 4 are energized through the separators 5 and 6, respectively. As described above, the cathode separator 5 of one single cell 7 is connected to the anode separator of the other single cell 7. By laminating 6, each single cell 7, 7 is advantageously connected in series.

  The single cells 7 and 7 are sandwiched between the end plates 14 and 14 via the insulating members 13 and 13 and are fixed to each other by the bolts 15 and nuts 16 attached to the end plates 14 and 14. Has been. That is, in the high-pressure hydrogen production apparatus 1 of the present embodiment, the solid polymer electrolyte membrane 2, the power feeders 3 and 4, and the separators 5 and 6 are fixed by the end plate 14, the bolt 15, and the nut 16. Means are formed. In the high-pressure hydrogen production apparatus 1, the solid polymer electrolyte membrane 2, each of the power feeders 3, 4, with a pressing stress larger than the pressure of the hydrogen gas obtained in the single cell 7 by the bolt 15 and the nut 16, The separators 5 and 6 are fixed. The hydrogen outlet 9, the water inlet 11, and the drain 12 are all provided between the single cells 7 and 7, and are provided through the insulating member 13 and the end plate 14.

In the high-pressure hydrogen production apparatus 1, the solid polymer electrolyte membrane 2 is a cation permeable membrane, and for example, Nafion (registered trademark, manufactured by DuPont), Aciplex (trade name, manufactured by Asahi Kasei Co., Ltd.) or the like can be used. The solid polymer electrolyte membrane 2 includes a catalyst layer (not shown) including, for example, a RuIrFeO _X catalyst on the anode side, and a catalyst layer (not illustrated) including, for example, a platinum catalyst, on the cathode side.

  The cathode power supply 3 and the anode power supply 4 can be formed of, for example, a titanium porous sintered body. The titanium porous sintered body is filled with a spherical gas atomized titanium powder produced by, for example, a gas atomizing method for solidifying molten droplets of titanium during scattering into a predetermined shaped sintering vessel and vacuum sintered. can get.

  The cathode separator 5 and the anode separator 6 are formed of, for example, a titanium plate, and the cathode feeder 3 and the anode feeder 4 are press-fitted into the cathode separator 5 and the anode separator 6 in which the fluid passages 8 and 10 are processed. Has been. At this time, it is preferable to cut the cathode separator 5 and the anode separator 6 so that the step between the cathode separator 5 and the cathode power supply 3 and the step between the anode separator 6 and the anode power supply 4 are eliminated. By eliminating the step, damage to the solid polymer electrolyte membrane 2 is avoided when the solid polymer electrolyte membrane 2, the power feeders 3 and 4, and the separators 5 and 6 are fixed by the pressing stress. be able to.

  Next, the operation of the high pressure hydrogen production apparatus 1 will be described.

  In the high-pressure hydrogen production apparatus 1 having the above-described configuration, water is supplied from the water supply port 11 to the fluid passage 10 of the anode separator 6, and the cathode power supply 3 and the anode power supply 4 are connected via the cathode separator 5 and the anode separator 6. The water is electrolyzed by energizing each of them. According to the electrolysis, hydrogen ions, electrons, and oxygen gas are generated in the fluid passage 10, and the hydrogen ions are solid cation permeable membranes due to a potential difference between the cathode power supply 3 and the anode power supply 4. It passes through the molecular electrolyte membrane 2 and moves to the cathode power supply 3 side. The hydrogen ions receive electrons from the cathode power supply 3 and are molecularized, whereby high-pressure hydrogen gas is obtained in the fluid passage 8 of the cathode separator 6.

  On the other hand, the oxygen gas produced in the fluid passage 10 is discharged from the drain port 12 together with water. However, in this way, the balance of pressure is lost on the cathode side and the anode side, and the solid polymer electrolyte membrane 2 and the anode are discharged. The power feeder 4 is pressed toward the anode separator 6.

  At this time, in the high-pressure hydrogen production apparatus 1, hydrogen gas generated in the fluid passage 8 by the solid polymer electrolyte membrane 2, the power feeders 3 and 4, and the separators 5 and 6 in advance by the bolts 15 and nuts 16. It is pressed and fixed with a pressing stress larger than the pressure. Therefore, when the solid polymer electrolyte membrane 2 and the anode power supply 4 are pressed toward the anode separator 6, the cathode power supply 3 can be further pressed against the solid polymer electrolyte membrane 2.

  As a result, in the high-pressure hydrogen production apparatus 1, the contact between the solid polymer electrolyte membrane 2 and the cathode power feeder 3 is maintained, and no gap is generated between the two, and the electrolytic voltage can be maintained substantially constant. it can. The pressing stress by the bolt 15 and the nut 16 is preferably in the range of 10 to 20 MPa exceeding the pressure of hydrogen gas generated in the fluid passage 8 in order to maintain the electrolytic voltage substantially constant.

  Next, when the pressure of the hydrogen gas generated in the fluid passage 8 is set to 35 MPa at the maximum, and the pressing stress by the bolt 15 and the nut 16 is set to 40 MPa of 5 MPa exceeding the pressure of the hydrogen gas (Example), FIG. 2 shows a change in the electrolysis voltage with respect to the pressure of the hydrogen gas when the pressing stress by the nut 16 exceeds the pressure of the hydrogen gas and is 10 MPa which is less than 1 MPa (comparative example).

  From FIG. 2, it is apparent that the electrolytic voltage can be maintained substantially constant when the pressing stress by the bolt 15 and the nut 16 is 40 MPa (Example) exceeding the pressure of the hydrogen gas. On the other hand, when the pressing stress by the bolt 15 and the nut 16 exceeds the pressure of the hydrogen gas and is 10 MPa which is less than 1 MPa (comparative example), the pressure of the hydrogen gas generated in the fluid passage 8 increases. Thus, it is clear that the electrolysis voltage is remarkably increased and the electrolysis efficiency is lowered.

Explanatory sectional drawing which shows the structure of the high pressure hydrogen production apparatus of this invention. The graph which shows the relationship between the pressure of the produced | generated hydrogen gas and the electrolysis voltage in the high pressure hydrogen production apparatus shown in FIG. The principal part enlarged view of the high pressure hydrogen production apparatus shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... High pressure hydrogen production apparatus, 2 ... Solid polymer electrolyte membrane, 3 ... Cathode feeder, 4 ... Anode feeder, 5 ... Cathode separator, 6 ... Anode separator, 7 ... Single cell, 14, 15, 16 ... Fixing means .

Claims (3)

A solid polymer electrolyte membrane, a cathode power supply provided on opposite sides of the solid polymer electrolyte membrane, an anode power supply, a cathode separator laminated on each power supply, and an anode separator. At least one single cell and a fixing means for fixing the solid polymer electrolyte membrane, each power supply, and each separator are provided from both sides of the single cell, and supplied to the anode side by energizing each power supply. In high-pressure hydrogen production equipment that electrolyzes water and generates high-pressure hydrogen gas on the cathode side,
The high-pressure hydrogen production apparatus characterized in that the fixing means has a pressing stress larger than the pressure of hydrogen gas obtained in the single cell.   The high-pressure hydrogen production apparatus according to claim 1, comprising a plurality of the single cells stacked on each other.   The high-pressure hydrogen production apparatus according to claim 1 or 2, wherein the fixing means includes a pressing stress that is larger in a range of 1 to 40 MPa than a pressure of hydrogen gas obtained in the single cell.

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