JP4531522B2 - High pressure hydrogen production equipment - Google Patents

Description

  The present invention relates to a high-pressure hydrogen production apparatus that obtains high-pressure hydrogen gas by electrolysis of water.

  Conventionally, as shown in FIG. 3, a solid polymer electrolyte membrane 2, a cathode power supply 3 provided opposite to each other, an anode power supply 4, and a cathode chamber in which the cathode power supply 3 is exposed. There is known a high-pressure hydrogen production apparatus 21 that includes 5 and an anode chamber 6 in which the anode feeder 4 is exposed.

  In the high-pressure hydrogen production apparatus 21, water is supplied from the water supply conduit 7 to the anode chamber 6, and when the cathode power supply 3 and the anode power supply 4 are energized, the water supplied to the anode chamber 6 is electrolyzed to generate hydrogen ions. And oxygen gas. The hydrogen ions permeate the solid polymer electrolyte membrane 2 and move to the cathode power supply 3 side, receive electrons from the cathode power supply 3 and become hydrogen gas. As a result, the high-pressure hydrogen production apparatus 21 can obtain high-pressure hydrogen gas in the cathode chamber 5.

  By the way, it is known that the hydrogen ions accompany water when passing through the solid polymer electrolyte membrane 2 and moving toward the cathode power supply 3, and this water is stored in the cathode chamber 5. Therefore, when the amount of water stored in the cathode chamber 5 reaches a predetermined amount, the supply of water to the anode chamber 6 is stopped, and the water stored in the cathode chamber 5 is changed to the pressure of hydrogen gas in the cathode chamber 5. Thus, a technique is known in which the water is moved to the anode power feeder 4 side through the solid polymer electrolyte membrane 2 and the water is electrolyzed (see, for example, Patent Document 1).

  Further, in the high-pressure hydrogen production apparatus 21, water is supplied to the cathode chamber 5 instead of supplying water to the anode chamber 6, and the water supplied to the cathode chamber 5 is supplied to the anode feeder 4 through the solid polymer electrolyte membrane 2. There is also known a technique for electrolyzing the water by moving the cathode power supply 3 and the anode power supply 4 by moving the cathode power supply 3 and the anode power supply 4 (see, for example, Patent Document 2).

However, in the high-pressure hydrogen production apparatus 21, when there is no water stored in the cathode chamber 5, the hydrogen gas in the cathode chamber 5 permeates into the anode chamber 6 through the solid polymer electrolyte membrane 2 while the electrolysis is stopped. There is an inconvenience of becoming.
JP 2003-328170 A Special table 2003-515237 gazette

  An object of the present invention is to provide a high-pressure hydrogen production apparatus capable of eliminating such disadvantages and reducing the permeation amount of hydrogen gas generated on the cathode side to the anode side.

In order to achieve such an object, the high-pressure hydrogen production apparatus of the present invention includes a solid polymer electrolyte membrane having a catalyst on both sides, and a cathode power supply provided opposite to both sides of the solid polymer electrolyte membrane. An anode feeder, a cathode chamber in which the cathode feeder is exposed, and an anode chamber in which the anode feeder is exposed. Water supplied to the anode chamber by energizing each feeder In a high-pressure hydrogen production apparatus that generates high-pressure hydrogen gas in the cathode chamber and oxygen in the anode chamber, a horizontally disposed solid polymer electrolyte membrane and an upper side of the solid polymer electrolyte membrane The cathode chamber is provided with a water layer that always covers the cathode power supply .

  In the high-pressure hydrogen production apparatus of the present invention, water is supplied to the anode chamber, and when each power feeder is energized, the water supplied to the anode chamber is electrolyzed to generate hydrogen ions and oxygen ions. The hydrogen ions pass through the solid polymer electrolyte membrane and move to the cathode power supply side, receive electrons from the cathode power supply body, and become hydrogen gas. As a result, high-pressure hydrogen gas is generated in the cathode chamber.

At this time, in the high-pressure hydrogen production apparatus of the present invention, the solid polymer electrolyte membrane is disposed horizontally, and the cathode chamber is provided above the solid polymer electrolyte membrane. The cathode chamber is always provided with an aqueous layer. As a result, in the cathode chamber, the cathode power supply is always covered with the water layer, and the high-pressure hydrogen gas generated in the cathode chamber is not applied to the solid polymer electrolyte membrane without passing through the water layer. Can't touch.

Therefore, according to the high-pressure hydrogen production apparatus of the present invention, the water layer does not disappear over the cathode power supply body in the cathode chamber, and the permeation amount of the hydrogen gas generated in the cathode chamber to the anode chamber is remarkably reduced. can do.

  The high-pressure hydrogen production apparatus of the present invention includes a water circulation means for taking out water supplied to the anode chamber from the anode chamber and circulating it again to the anode chamber, and water electrolyzed from the water circulated by the water circulation means. It is preferable to include an oxygen removing means for removing the generated oxygen.

  In the high-pressure hydrogen production apparatus of the present invention, since the cathode power supply is provided above the horizontally disposed solid polymer electrolyte membrane, the anode power supply provided opposite to the cathode power supply is provided. The body will be located below the solid polymer electrolyte membrane. Further, the anode chamber is provided further below the anode power feeder.

  As a result, when oxygen generated in the anode chamber by the electrolysis is vaporized, an oxygen gas layer is formed on the upper portion of the anode chamber, and the oxygen gas is supplied between the water supplied to the anode chamber and the anode feeder. A gas layer is interposed. When the oxygen gas layer is generated, the contact between the water supplied to the anode chamber and the anode power feeder is hindered, and the electrolysis efficiency is lowered.

  Therefore, in the high pressure hydrogen production apparatus of the present invention, the water supplied to the anode chamber by the water circulation means is taken out from the anode chamber and circulated again to the anode chamber, and is circulated as described above by the oxygen removal means. Remove oxygen from water. As a result, formation of the oxygen gas layer in the anode chamber is prevented, and the electrolysis efficiency can be improved.

  Furthermore, the high-pressure hydrogen production apparatus of the present invention includes a high-pressure hydrogen tank that is connected to the cathode chamber via a connection conduit and stores the high-pressure hydrogen gas, and the connection conduit has a hydrogen gas pressure in the cathode chamber. It is preferable to provide an on-off valve that opens when the hydrogen gas pressure in the high-pressure hydrogen tank is higher than the hydrogen gas pressure in the cathode chamber and closes when the hydrogen gas pressure in the cathode chamber is lower than the hydrogen gas pressure in the high-pressure hydrogen tank.

  According to the high-pressure hydrogen production apparatus of the present invention, when the hydrogen gas pressure in the cathode chamber becomes equal to or higher than the hydrogen gas pressure in the high-pressure hydrogen tank as the electrolysis progresses, the on-off valve opens and the cathode Indoor hydrogen gas is transferred to the high-pressure hydrogen tank. When the hydrogen gas pressure in the cathode chamber becomes lower than the hydrogen gas pressure in the high-pressure hydrogen tank, the on-off valve closes and the cathode chamber and the high-pressure hydrogen tank are shut off. The hydrogen gas pressure in the tank does not act on the cathode chamber.

  Therefore, according to the high pressure hydrogen production apparatus of the present invention, the hydrogen gas pressure in the cathode chamber does not become higher than necessary, and the permeation amount of the hydrogen gas generated in the cathode chamber to the anode chamber is further reduced. can do.

  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 shows the hydrogen gas pressure in the cathode chamber and the hydrogen gas that permeates the anode chamber in the high-pressure hydrogen production apparatus shown in FIG. It is a graph which shows the relationship with quantity.

  As shown in FIG. 1, in the high-pressure hydrogen production apparatus 1 of this embodiment, a cathode power supply 3 and an anode power supply 4 are provided opposite to each other on both sides of a horizontally disposed solid polymer electrolyte membrane 2. The cathode feeder 3 is disposed above the solid polymer electrolyte membrane 2, and the anode feeder 4 is disposed below the solid polymer electrolyte membrane 2. The high-pressure hydrogen production apparatus 1 includes a cathode chamber 5 in which the cathode power supply 3 is exposed above the cathode power supply 3 and an anode in which the anode power supply 4 is exposed below the anode power supply 4. A chamber 6 is provided.

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) containing, for example, a RuIrFeO _X catalyst on the anode side, and a catalyst layer (not shown) containing, for example, a platinum catalyst, on the cathode side. Further, as the cathode power supply 3, for example, a porous body such as a titanium fiber sintered body or a titanium powder sintered body with a platinum plated surface can be used. As the anode power supply 4, for example, a titanium powder sintered body can be used. A porous body or the like whose surface is subjected to platinum plating can be used.

A branch pipe 8 branched from the water supply conduit 7 is connected to the cathode chamber 5 via a water supply valve 9, and the cathode power supply 3 is always covered with water supplied by the water supply conduit 7 and the branch pipe 8 when electrolysis is stopped. A water layer 10 is provided. When the inside of the cathode chamber 5 is at normal pressure, water can be supplied from the outside. However, when electrolysis starts and the inside of the cathode chamber 5 is pressurized, water cannot be supplied from the outside. . Therefore, as described above, water is supplied to the cathode chamber 5 through the water supply conduit 7 and the branch pipe 8 when the electrolysis is stopped.

  The cathode chamber 5 is connected to a high-pressure hydrogen tank 13 via a connection conduit 12 having an on-off valve 11. The on-off valve 11 opens when the pressure of the hydrogen gas in the cathode chamber 5 is equal to or higher than the pressure of the hydrogen gas in the high-pressure hydrogen tank 13, and the pressure of the hydrogen gas in the cathode chamber 5 is the hydrogen gas in the high-pressure hydrogen tank 13. The valve is closed when the pressure is lower. The on-off valve 11 is immediately closed when the electrolysis is stopped.

  On the other hand, a branch pipe 14 branched from the water supply conduit 7 is connected to the anode chamber 6 via a water supply valve 15 so that the water supplied by the water supply conduit 7 and the branch pipe 14 is filled inside. At this time, the anode chamber 6 is provided with a water circulation conduit 16 that takes out water filling the inside from the anode chamber 6 and circulates it again to the anode chamber 6. An oxygen removing device 18, a pump 19, and an on-off valve 20 are provided. The branch pipe 14 is connected to the water circulation conduit 16 between the oxygen removing device 18 and the pump 19. As the oxygen removing device 18, for example, a device for separating and removing oxygen by an oxygen separation membrane or the like can be used.

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

  In the high-pressure hydrogen production apparatus 1, first, the water supply valves 9 and 15 are opened, and water is supplied from the water supply conduit 7 to the cathode chamber 5 and the anode chamber 6. At this time, in the cathode chamber 5, a predetermined amount of water is supplied from the water supply conduit 7 through the branch pipe 8 so that a water layer 10 that covers the cathode power supply 3 is formed and a space is formed above the water layer 10. After that, the water supply valve 9 is closed. On the other hand, in the anode chamber 6, the water supplied from the water supply conduit 7 through the branch pipe 14 is filled into the room, and then the water supply valve 15 is closed.

  Next, the on-off valves 17 and 20 of the water circulation conduit 16 are opened and the pump 19 is operated to take out the water in the anode chamber 6 from the anode chamber 6 and again through the oxygen removing device 18 to the anode chamber 6. Cycle to return to. Then, electrolysis is started by supplying power to the cathode power feeder 3 and the anode power feeder 4 from a power supply device (not shown).

  In this way, hydrogen ions and oxygen ions are generated in the anode chamber 6 mainly by electrolysis of the water supplied to the anode chamber 6. The hydrogen ions permeate the solid polymer electrolyte membrane 2 with water and move to the cathode power supply 3 side, and receive electrons from the cathode power supply 3 to generate hydrogen gas in the cathode chamber 5. As the electrolysis proceeds, the pressure of the hydrogen gas in the cathode chamber 5 gradually increases, and high-pressure hydrogen gas is obtained.

When the pressure of the hydrogen gas in the cathode chamber 5 increases, there is a concern that the hydrogen gas permeates the solid polymer electrolyte membrane 2 and leaks to the anode chamber 6 side. However, since the cathode chamber 5 is always provided with the water layer 10 that covers the cathode power supply 3 , the hydrogen gas cannot contact the solid polymer electrolyte membrane 2 without passing through the water layer 10. . Therefore, the hydrogen gas does not directly contact the solid polymer electrolyte membrane 2, and the permeation amount of the hydrogen gas to the anode chamber 6 side can be significantly reduced.

  The on-off valve 11 provided in the connection conduit 12 that connects the cathode chamber 5 and the high-pressure hydrogen tank 13 is configured so that the hydrogen gas pressure in the cathode chamber 5 is lower than the hydrogen gas pressure in the high-pressure hydrogen tank 13. Although it is closed, when the pressure of the hydrogen gas in the cathode chamber 5 becomes equal to or higher than the pressure of the hydrogen gas in the high-pressure hydrogen tank 13, the valve is opened, and the hydrogen gas in the cathode chamber 5 is moved into the high-pressure hydrogen tank 13. The on-off valve 11 is closed again when the hydrogen gas pressure in the cathode chamber 5 becomes lower than the hydrogen gas pressure in the high-pressure hydrogen tank 13 due to the movement of the hydrogen gas. As described above, the on-off valve 11 is immediately closed even when the electrolysis is stopped.

  As a result, the hydrogen gas in the cathode chamber 5 is moved into the high-pressure hydrogen tank 13 whenever the pressure becomes higher than the pressure of the hydrogen gas in the high-pressure hydrogen tank 13. The pressure can be prevented from becoming higher than necessary, and the high-pressure hydrogen tank 13 can be handled independently.

  The high-pressure hydrogen production apparatus 1 does not include the high-pressure hydrogen tank 13 or always opens the on-off valve 11 provided in the connection conduit 12 that connects the cathode chamber 5 and the high-pressure hydrogen tank 13. Good. However, in this case, the permeation amount of the hydrogen gas to the anode chamber 6 side becomes larger than the case where the on-off valve 11 is opened and closed according to the pressure of the hydrogen gas in the cathode chamber 5 as described above.

  On the other hand, in the high-pressure hydrogen production apparatus 1, there is also movement of water from the cathode chamber 5 to the anode feeder 4 side, and this water is also electrolyzed to generate hydrogen ions and oxygen gas in the anode chamber 6. As described above, the hydrogen ions move to the cathode power supply 3 side with water, and hydrogen gas is generated in the cathode chamber 5. Therefore, the high-pressure hydrogen production apparatus 1 appropriately adjusts the amount of water in the water layer 10 formed in the cathode chamber 5, and the amount of water that moves from the anode chamber 6 to the cathode chamber 5 along with hydrogen ions, By balancing the amount of water moving from the chamber 5 to the anode chamber 6, it is possible to dispense with the supply of new water during the electrolysis.

  Further, during the electrolysis, oxygen gas is generated in the anode chamber 6 as described above. A small amount of the oxygen gas is dissolved in the water in the anode chamber 6. However, when the amount of the oxygen gas increases as the electrolysis progresses, the oxygen gas is vaporized to form an oxygen gas layer on the upper portion of the anode chamber 6. Concerned. When the oxygen gas layer is formed, the contact between the water in the anode chamber 6 and the anode feeder 4 is hindered, and the efficiency of electrolysis is lowered.

  However, in the high-pressure hydrogen production apparatus 1, as described above, the water in the anode chamber 6 is circulated through the water circulation conduit 16, and the oxygen removal device 18 provided in the middle of the water circulation conduit 16 converts the water in the anode chamber 6 into water. The oxygen contained is removed. Therefore, formation of the oxygen gas layer in the anode chamber 6 can be prevented.

  Next, examples of the present invention and comparative examples will be described.

In the present embodiment, in the high-pressure hydrogen production apparatus 1 shown in FIG. 1, the water layer 10 that always covers the cathode power supply 3 is provided in the cathode chamber 5, and the anode chamber 6 is filled with water. Decomposition was performed to produce high-pressure hydrogen gas. At this time, the on-off valve 11 provided in the connection conduit 12 connecting the cathode chamber 5 and the high-pressure hydrogen tank 13 has a hydrogen gas pressure in the cathode chamber 5 lower than the hydrogen gas pressure in the high-pressure hydrogen tank 13. The valve is sometimes closed and the valve is opened when the pressure of the hydrogen gas in the cathode chamber 5 becomes equal to or higher than the pressure of the hydrogen gas in the high-pressure hydrogen tank 13.

  Then, the amount of hydrogen gas permeated to the anode chamber 6 side with respect to the pressure of the hydrogen gas in the cathode chamber 5 was measured. The results are shown in FIG.

In this embodiment, high-pressure hydrogen gas is produced in exactly the same manner as in Embodiment 1, except that the on-off valve 11 provided in the connection conduit 12 connecting the cathode chamber 5 and the high-pressure hydrogen tank 13 is always open. did. Then, the amount of hydrogen gas permeated to the anode chamber 6 side with respect to the pressure of the hydrogen gas in the cathode chamber 5 was measured. The results are shown in FIG.
[Comparative Example 1]
In this comparative example, high-pressure hydrogen gas was produced in exactly the same manner as in Example 1 except that no water layer 10 was provided in the cathode chamber 5. Then, the amount of hydrogen gas permeated to the anode chamber 6 side with respect to the pressure of the hydrogen gas in the cathode chamber 5 was measured. The results are shown in FIG.

From FIG. 2, when the water layer 10 is provided in the cathode chamber 5 and the cathode feeder 3 is always covered with the water layer 10 (Examples 1 and 2), the water layer 10 is not provided at all (comparison). Compared to Example 1), it is clear that the hydrogen gas permeation from the cathode chamber 5 to the anode chamber 6 can be significantly reduced.

  2, the water layer 10 is provided in the cathode chamber 5, and the on-off valve 11 provided in the connection conduit 12 that connects the cathode chamber 5 and the high-pressure hydrogen tank 13 is connected to the hydrogen gas in the cathode chamber 5. Is closed when the pressure of the hydrogen gas in the high-pressure hydrogen tank 13 is lower than the pressure of the hydrogen gas in the high-pressure hydrogen tank 13, and the valve is opened when the pressure of the hydrogen gas in the cathode chamber 5 exceeds the pressure of the hydrogen gas in the high-pressure hydrogen tank 13 (Example). 1), it is apparent that the permeation amount of hydrogen gas from the cathode chamber 5 to the anode chamber 6 can be further remarkably reduced.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory sectional drawing which shows one structural example of the high pressure hydrogen production apparatus based on this invention. The graph which shows the relationship between the pressure of the hydrogen gas in a cathode chamber, and the amount of hydrogen gas which permeate | transmits an anode chamber. Explanatory sectional drawing which shows the example of 1 structure of the conventional high pressure hydrogen production apparatus.

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 chamber, 6 ... Anode chamber, 10 ... Aqueous layer, 11 ... On-off valve, 12 ... Connection Conduit, 13 ... High-pressure hydrogen tank, 16 ... Water circulation means, 19 ... Oxygen removal means.

Claims (3)

A solid polymer electrolyte membrane; a cathode feeder provided opposite to both sides of the solid polymer electrolyte membrane; an anode feeder; a cathode chamber in which the cathode feeder is exposed; and an anode inside An anode chamber in which the power supply body is exposed, and by supplying electricity to each power supply body, the water supplied to the anode chamber is electrolyzed to generate high-pressure hydrogen gas in the cathode chamber and oxygen in the anode chamber. In high-pressure hydrogen production equipment,
A solid polymer electrolyte membrane disposed horizontally and a cathode power supply provided above the solid polymer electrolyte membrane, wherein the cathode chamber always includes a water layer covering the cathode power supply. High-pressure hydrogen production equipment.   Water circulating means for taking out water supplied to the anode chamber from the anode chamber and circulating it again to the anode chamber; and oxygen removing means for removing oxygen generated by the electrolysis from the water circulated by the water circulating means. The high-pressure hydrogen production apparatus according to claim 1, comprising:   A high-pressure hydrogen tank connected to the cathode chamber via a connecting conduit and storing the high-pressure hydrogen gas, the connecting conduit having a hydrogen gas pressure in the cathode chamber equal to or higher than the hydrogen gas pressure in the high-pressure hydrogen tank; The high-pressure hydrogen production apparatus according to claim 1 or 2, further comprising an on-off valve that is opened when the hydrogen gas pressure in the cathode chamber is lower than the hydrogen gas pressure in the high-pressure hydrogen tank. .

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