JP2017203188A - Differential pressure type high-pressure water electrolysis apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and surely suppress damage to an electrolyte membrane caused by high-pressure compression, in particular, to enable sealability to be surely held between the electrolyte membrane and an insulating reinforcing member.SOLUTION: A high-pressure water electrolysis cell 12 constituting a differential pressure type high-pressure water electrolysis apparatus 10 sandwiches an electrolyte membrane/electrode structure 32 with an anode separator 34 and a cathode separator 36. On the outer periphery of a seal member 70, a resin sheet member 62 is arranged corresponding to a portion high-pressure compressed between the anode separator 34 and the cathode separator 36 by fastening. A portion where the resin sheet member 62 and a solid polymer electrolyte membrane 40 overlap each other is bonded by an adhesive 64.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a differential pressure type high pressure water electrolysis apparatus that electrolyzes water to generate oxygen and hydrogen having a pressure higher than that of the oxygen.

  Generally, hydrogen is used as a fuel gas used for a power generation reaction of a fuel cell. Hydrogen is produced by, for example, a water electrolysis device. The water electrolysis apparatus uses a solid polymer electrolyte membrane (ion exchange membrane) in order to decompose water and generate hydrogen (and oxygen).

  Electrocatalyst layers are provided on both sides of the solid polymer electrolyte membrane to constitute an electrolyte membrane / electrode structure, and power feeding bodies are disposed on both sides of the electrolyte membrane / electrode structure to perform water electrolysis. The cell is configured.

  Therefore, in a water electrolysis apparatus in which a plurality of water electrolysis cells are stacked, a voltage is applied to both ends in the stacking direction, and water is supplied to the anode feeder. For this reason, on the anode side of the electrolyte membrane / electrode structure, water is decomposed to generate hydrogen ions (protons), and these hydrogen ions permeate the solid polymer electrolyte membrane and move to the cathode side. In combination with electrons, hydrogen is produced. On the other hand, on the anode side, oxygen generated together with hydrogen is discharged to the outside of the water electrolysis apparatus along with excess water.

  As this type of water electrolysis apparatus, a differential pressure type high pressure water electrolysis apparatus that produces oxygen on the anode side by electrolysis of water and produces hydrogen at a higher pressure than oxygen on the cathode side is employed. At that time, when the solid polymer electrolyte membrane is sandwiched between the anode separator and the cathode separator, the solid polymer electrolyte membrane is compressed at a high pressure particularly on the outer periphery of the high-pressure seal portion. Accordingly, the solid polymer electrolyte membrane may be damaged by high-pressure compression.

  For this reason, for example, a differential pressure type high pressure water electrolysis apparatus disclosed in Patent Document 1 is known. In this differential pressure type high-pressure water electrolysis apparatus, an insulating reinforcing member is disposed on the outer periphery of the seal member in correspondence with a portion compressed by high pressure between the anode separator and the cathode separator by fastening. The insulating reinforcing member is set to have a higher compressive strength than the flat membrane member (electrolyte membrane).

  Therefore, it is possible to increase the strength of the portion subjected to high-pressure compression, and it is possible to easily and reliably suppress damage to the flat membrane member due to high-pressure compression, and to continue the water electrolysis operation satisfactorily. It can be done.

JP 2016-44353 A

  The present invention has been made in connection with this kind of technical idea, and can easily and reliably suppress damage to the electrolyte membrane due to high-pressure compression, and in particular, between the electrolyte membrane and the insulating reinforcing member. It is an object of the present invention to provide a differential pressure type high pressure water electrolysis apparatus that can reliably maintain the sealing performance.

  The differential pressure type high-pressure water electrolysis apparatus according to the present invention includes a high-pressure water electrolysis cell, and a plurality of the high-pressure water electrolysis cells are stacked and fastened in the stacking direction. The high-pressure water electrolysis cell includes an electrolyte membrane, an anode power supply body and a cathode power supply body provided on both sides of the electrolyte membrane, an anode separator, and a cathode separator.

  The anode separator is disposed opposite to the anode power supply body and has an anode chamber in which oxygen is generated by electrolyzing supplied water. The cathode separator is disposed opposite to the cathode power supply body and includes a cathode chamber in which hydrogen having a pressure higher than oxygen is generated by electrolysis of water.

  In the differential pressure type high pressure water electrolysis apparatus, an insulating reinforcing member having a compressive strength higher than that of the electrolyte membrane is provided on the outer periphery of the electrolyte membrane, corresponding to a portion compressed at a high pressure between the anode separator and the cathode separator by fastening. Has been placed. And the site | part with which an electrolyte membrane and an insulating reinforcement member overlap along the lamination direction is joined by the adhesive agent.

  Moreover, in this differential pressure type high pressure water electrolysis apparatus, it is preferable that the adhesive contains an epoxy group.

  Furthermore, in this differential pressure type high pressure water electrolysis apparatus, it is preferable that the adhesive has a thickness of 30 μm or more in the lamination direction in a cured state.

  Furthermore, in this differential pressure type high pressure water electrolysis apparatus, it is preferable that the adhesive has a fluorine-based main skeleton.

  Moreover, in this differential pressure type high pressure water electrolysis apparatus, it is preferable that the seal member overlaps the part where the electrolyte membrane and the insulating reinforcing member overlap.

  According to the present invention, the insulating reinforcing member having a compressive strength higher than that of the electrolyte membrane is disposed corresponding to the portion compressed by high pressure between the anode separator and the cathode separator by fastening. For this reason, it is possible to easily and reliably suppress damage to the electrolyte membrane due to high pressure compression, and it is possible to continue the water electrolysis operation satisfactorily.

  Moreover, the portion where the electrolyte membrane and the insulating reinforcing member overlap along the stacking direction is joined by an adhesive. Therefore, even when the electrolyte membrane is compressed at the overlapping portion of the electrolyte membrane and the insulating reinforcing member and the film thickness is reduced, the bonding strength of the overlapping portion is maintained, and the sealing property is maintained over a long period of time. Can be reliably held.

1 is a perspective explanatory view of a differential pressure type high pressure water electrolysis apparatus according to a first embodiment of the present invention. It is a cross-sectional explanatory drawing of the high pressure water electrolysis cell which comprises the said differential pressure type high pressure water electrolysis apparatus. It is explanatory drawing of the relationship between the thickness of an adhesive agent, and joining strength. It is a section explanatory view of a high pressure water electrolysis cell which constitutes a differential pressure type high pressure water electrolysis device concerning a 2nd embodiment of the present invention.

  As shown in FIG. 1, in the differential pressure type high pressure water electrolysis apparatus 10 according to the first embodiment of the present invention, a plurality of high pressure water electrolysis cells 12 are arranged vertically (arrow A direction) or horizontally (arrow B direction). A laminated body 14 is provided.

  At one end (upper end) in the stacking direction of the stacked body 14, a terminal plate 16a, an insulating plate 18a, and an end plate 20a are sequentially disposed upward. Similarly, a terminal plate 16b, an insulating plate 18b, and an end plate 20b are sequentially disposed on the other end (lower end) in the stacking direction of the stacked body 14 in a downward direction.

  The differential pressure type high pressure water electrolysis apparatus 10 integrally clamps and holds the disc-shaped end plates 20a and 20b in the stacking direction via four tie rods 22 extending in the direction of arrow A, for example. The differential pressure type high pressure water electrolysis apparatus 10 is fastened in a state where a tightening load in the stacking direction (arrow A direction) is applied to the plurality of high pressure water electrolysis cells 12.

  The differential pressure type high pressure water electrolysis apparatus 10 may employ a configuration in which the differential pressure type high pressure water electrolysis apparatus 10 is integrally held by a box-shaped casing (not shown) including the end plates 20a and 20b as end plates. Moreover, although the differential pressure type high pressure water electrolysis apparatus 10 has a substantially cylindrical shape as a whole, it can be set in various shapes such as a cubic shape.

  Terminal portions 24a and 24b are provided on the side portions of the terminal plates 16a and 16b so as to protrude outward. The terminal portions 24a and 24b are electrically connected to the electrolytic power source 28 via the wirings 26a and 26b.

  As shown in FIG. 2, the high-pressure water electrolysis cell 12 includes a substantially disc-shaped electrolyte membrane / electrode structure 32, and an anode separator 34 and a cathode separator 36 that sandwich the electrolyte membrane / electrode structure 32.

  A water supply communication hole 38a for supplying water (pure water) is provided at the outer peripheral edge of the high-pressure water electrolysis cell 12 so as to communicate with each other in the stacking direction (arrow A direction). In order to discharge oxygen generated by the reaction and unreacted water (mixed fluid) to the outer peripheral edge of the high-pressure water electrolysis cell 12 in communication with each other in the stacking direction at a position diagonal to the water supply communication hole 38a. The water discharge communication hole 38b is provided.

  A high-pressure hydrogen communication hole 38c is provided at the center of the high-pressure water electrolysis cell 12 so as to penetrate the substantial center of the electrolysis region and communicate with each other in the stacking direction. The high-pressure hydrogen communication hole 38c discharges high-pressure hydrogen generated by the reaction (hydrogen higher than the generated oxygen) (for example, 1 MPa to 80 MPa).

  The anode separator 34 and the cathode separator 36 have a substantially disc shape and are made of, for example, a carbon member. In addition, the anode separator 34 and the cathode separator 36 are formed by pressing or cutting a steel plate, a stainless steel plate, a titanium plate, an aluminum plate, a plated steel plate, or a metal plate whose surface has been subjected to anticorrosion treatment. After that, a surface treatment for anticorrosion is performed. The anode separator 34 and the cathode separator 36 may be configured in a flat plate shape.

  The electrolyte membrane / electrode structure 32 includes a solid polymer electrolyte membrane (electrolyte membrane) 40 having a substantially ring shape. The solid polymer electrolyte membrane 40 is sandwiched between an anode power supply 42 and a cathode power supply 44 for electrolysis having a ring shape. The solid polymer electrolyte membrane 40 is composed of, for example, a hydrocarbon (HC) -based membrane (flat membrane) or a fluorine-based membrane (flat membrane), and is more predetermined than the anode feeder 42 and the cathode feeder 44. Only the dimension is set to a large diameter.

  The solid polymer electrolyte membrane 40 is formed with a high-pressure hydrogen communication hole 38c at a substantially central portion. An anode electrode catalyst layer 42 a having a ring shape is provided on one surface of the solid polymer electrolyte membrane 40. A cathode electrode catalyst layer 44 a having a ring shape is formed on the other surface of the solid polymer electrolyte membrane 40. The anode electrode catalyst layer 42a uses, for example, a Ru (ruthenium) -based catalyst, and the cathode electrode catalyst layer 44a uses, for example, a platinum catalyst.

  The anode power supply body 42 and the cathode power supply body 44 are constituted by a sintered body (porous conductor) of spherical atomized titanium powder, for example. The anode power supply body 42 and the cathode power supply body 44 are provided with a smooth surface portion that is etched after the grinding process, and the porosity is set within a range of 10% to 50%, more preferably 20% to 40%. . The anode power supply 42 is set to have a larger diameter than the cathode power supply 44 by a predetermined dimension.

  An anode chamber 46 is formed on the surface 34 a of the anode separator 34 facing the electrolyte membrane / electrode structure 32 by forming a ring-shaped recess. The anode chamber 46 communicates with a supply passage 48a communicating with the water supply communication hole 38a and a discharge passage 48b communicating with the water discharge communication hole 38b. A water flow path member 50 is disposed on the surface of the anode power supply body 42 facing the bottom surface of the anode chamber 46. The water channel member 50 is provided with a water channel 50a communicating with the supply passage 48a and the discharge passage 48b.

  In the anode chamber 46, an anode power supply 42 and a ring-shaped protective sheet member 52 interposed between the anode power supply 42 and the solid polymer electrolyte membrane 40 are disposed. The protective sheet member 52 has an inner peripheral position disposed inward of the inner peripheral positions of the anode power supply body 42 and the cathode power supply body 44, and is set to have the same diameter as the anode power supply body 42. A plurality of through holes 52 a are formed in the protective sheet member 52.

  A cathode chamber 54 is formed on the surface 36 a of the cathode separator 36 facing the solid polymer electrolyte membrane 40 by cutting out into a substantially ring shape. In the cathode chamber 54, a cathode power supply body 44 and a load applying mechanism 56 that presses the cathode power supply body 44 against the solid polymer electrolyte membrane 40 are disposed.

  The load applying mechanism 56 includes an elastic member, for example, a plate spring 58, and the plate spring 58 applies a load to the cathode power supply body 44 through the hydrogen flow path member 60. The hydrogen flow path member 60 is provided with a hydrogen flow path 60a, and the hydrogen flow path 60a communicates with the high-pressure hydrogen communication hole 38c through the hydrogen discharge path 48c. In addition to the leaf spring 58, a disc spring, a coil spring, or the like can be used as the elastic member.

  The solid polymer electrolyte membrane 40 is set to have a diameter dimension accommodated in the cathode chamber 54. An insulating reinforcing member, for example, a resin sheet member 62 is disposed so as to partially overlap the outer peripheral edge of the solid polymer electrolyte membrane 40 in the stacking direction (having an overlapping portion). The overlapping portion of the inner peripheral edge portion of the resin sheet member 62 and the outer peripheral edge portion of the solid polymer electrolyte membrane 40 is joined by an adhesive 64, and the resin sheet member 62 is formed between the anode separator 34 and the cathode separator 36. Sandwiched between. The resin sheet member 62 may be configured not to be directly sandwiched between the anode separator 34 and the cathode separator 36.

  In addition to insulation, the resin sheet member 62 is made of a material having strength and acid resistance and higher compressive strength than the solid polymer electrolyte membrane 40. As the resin sheet member 62, for example, PEN (polyethylene naphthalate), polyimide film, PPS (polyphenylene sulfide), or the like is used.

  The adhesive 64 is an epoxy resin adhesive containing an epoxy group, and has a fluorine-based main skeleton. The adhesive 64 is cured and has a thickness of 30 μm or more in the stacking direction.

  Between the anode separator 34 and the cathode separator 36, a seal member (gasket) 66a that circulates in the water supply communication hole 38a and a seal member (gasket) 66b that circulates in the water discharge communication hole 38b are interposed. Between the central part of the anode separator 34 and the central part of the solid polymer electrolyte membrane 40, a seal member (gasket) 68 a that goes around the high-pressure hydrogen communication hole 38 c is interposed. A seal member (gasket) 68b that goes around the high-pressure hydrogen communication hole 38c is interposed between the central portion of the cathode separator 36 and the central portion of the solid polymer electrolyte membrane 40.

  A seal member (gasket) 70 is disposed around the cathode chamber 54 on the surface 36 a of the cathode separator 36 facing the electrolyte membrane / electrode structure 32. The seal member 70 is disposed at an overlapping portion between the inner peripheral edge of the resin sheet member 62 and the outer peripheral edge of the solid polymer electrolyte membrane 40, and comes into contact with the solid polymer electrolyte membrane 40.

  As shown in FIG. 1, pipes 72a, 72b, and 72c communicating with the water supply communication hole 38a, the water discharge communication hole 38b, and the high-pressure hydrogen communication hole 38c are connected to the end plate 20a. Although not shown, the pipe 72c is provided with a back pressure valve (or electromagnetic valve), and the pressure of hydrogen generated in the high-pressure hydrogen communication hole 38c can be maintained at a high pressure.

  The operation of the differential pressure type high pressure water electrolysis apparatus 10 configured as described above will be described below.

  As shown in FIG. 1, water is supplied from the pipe 72a to the water supply communication hole 38a of the differential pressure type high pressure water electrolysis apparatus 10, and is electrically connected to the terminal portions 24a and 24b of the terminal plates 16a and 16b. A voltage is applied via the electrolytic power supply 28. Therefore, as shown in FIG. 2, in each high pressure water electrolysis cell 12, water is supplied from the water supply communication hole 38a through the supply passage 48a of the anode separator 34 to the water passage 50a of the water passage member 50. Moves along the anode feeder 42.

  Accordingly, water is decomposed by electricity in the anode electrode catalyst layer 42a, and hydrogen ions, electrons, and oxygen are generated. Hydrogen ions generated by this anodic reaction permeate the solid polymer electrolyte membrane 40 and move to the cathode electrode catalyst layer 44a side, and combine with electrons to obtain hydrogen.

  Thereby, hydrogen flows along the hydrogen flow path 60 a of the hydrogen flow path member 60 from the inside of the cathode power supply body 44. Hydrogen can be taken out of the differential pressure type high-pressure water electrolysis apparatus 10 through the high-pressure hydrogen communication hole 38c from the hydrogen discharge passage 48c while being maintained at a higher pressure than the water supply communication hole 38a. On the other hand, oxygen generated by the reaction and unreacted water are discharged to the outside of the differential pressure type high-pressure water electrolysis apparatus 10 along the water discharge communication hole 38b.

  In this case, in the first embodiment, as shown in FIG. 2, the outer peripheral edge of the solid polymer electrolyte membrane 40 partially overlaps in the stacking direction, and the compressive strength is higher than that of the solid polymer electrolyte membrane 40. A resin sheet member 62 is disposed. For this reason, it is possible to increase the strength of the portion subjected to high-pressure compression, and it is possible to easily and reliably suppress damage to the solid polymer electrolyte membrane 40 due to high-pressure compression. And the water electrolysis operation by each high-pressure water electrolysis cell 12 can be continued favorably.

  Further, the overlapping portion where the inner peripheral edge portion of the resin sheet member 62 and the outer peripheral edge portion of the solid polymer electrolyte membrane 40 overlap along the stacking direction is joined by an adhesive 64. Therefore, even when the solid polymer electrolyte membrane 40 is compressed and the film thickness is reduced at the overlapping portion of the solid polymer electrolyte membrane 40 and the resin sheet member 62, the bonding strength of the overlapping portion is maintained. . Thereby, the effect that the solid polymer electrolyte membrane 40 and the resin sheet member 62 can reliably maintain the sealing property for a long period of time is obtained.

  The adhesive 64 contains an epoxy group. When the adhesive 64 containing an epoxy group is used, the bonding strength with the solid polymer electrolyte membrane 40 is particularly high. For this reason, in the joined body in which the resin sheet member 62 is bonded to the solid polymer electrolyte membrane 40 after the screen is coated with the adhesive 64, the desired joining strength is reliably maintained even when immersed in warm water for a long time. can do.

  On the other hand, in the adhesive containing no epoxy group, the same experiment as described above was performed, and as a result, the bonding strength was reduced.

  Furthermore, the adhesive 64 has a fluorine-based main skeleton. Therefore, the adhesive 64 has a low elution property to water, and even if it remains in water for a long time, it is possible to reliably maintain a desired bonding strength, and the ions from the adhesive 64 can be maintained. Since there is almost no elution, high quality hydrogen can be obtained.

  Furthermore, the adhesive 64 has a thickness of 30 μm or more in the stacking direction in a cured state. In the present embodiment, the solid polymer electrolyte membrane 40 and the resin sheet member 62 are bonded by an adhesive 64, and the adhesive 64 is cured by heating, and then disposed in water for a long time. Next, a 180 ° peel test was performed in an atmosphere of a predetermined temperature and a predetermined humidity.

  The result is shown in FIG. In FIG. 3, the thickness of the adhesive layer (adhesive 64) is set on the horizontal axis, and the bonding strength is set on the vertical axis. Thereby, the stable joining strength is acquired as the thickness of the hardened | cured adhesive 64 is 30 micrometers or more. For this reason, it can suppress favorably that the adhesive 64 is peeled off with a change in pressure from normal pressure to high pressure.

  FIG. 4 is a cross-sectional explanatory view of a high-pressure water electrolysis cell 82 constituting a differential pressure type high-pressure water electrolysis apparatus 80 according to the second embodiment of the present invention. In addition, the same referential mark is attached | subjected to the component same as the high pressure water electrolysis cell 12 which comprises the differential pressure type high pressure water electrolysis apparatus 10 which concerns on 1st Embodiment, and the detailed description is abbreviate | omitted.

  The high-pressure water electrolysis cell 82 includes an electrolyte membrane / electrode structure 84. An insulating reinforcing member, for example, a resin sheet member 86 is formed so as to partially overlap with the outer peripheral edge of the solid polymer electrolyte membrane 40 constituting the electrolyte membrane / electrode structure 84 in the stacking direction (with an overlapping portion). Be placed.

  The inner peripheral edge portion of the resin sheet member 86 is disposed on the solid polymer electrolyte membrane 40, and the inner peripheral edge portion and the solid polymer electrolyte membrane 40 are joined by an adhesive 64. The seal member 70 is disposed at an overlapping portion between the inner peripheral edge portion of the resin sheet member 86 and the outer peripheral edge portion of the solid polymer electrolyte membrane 40, and comes into contact with the resin sheet member 86.

  In the second embodiment configured as described above, the same effect as in the first embodiment can be obtained.

DESCRIPTION OF SYMBOLS 10, 80 ... Differential pressure type high voltage | pressure water electrolysis apparatus 12, 82 ... High pressure water electrolysis cell 14 ... Laminated body 16a, 16b ... Terminal plate 18a, 18b ... Insulation plate 20a, 20b ... End plate 24a, 24b ... Terminal part 28 ... Electrolytic power supply 32, 84 ... Electrolyte membrane / electrode structure 34 ... Anode separator 36 ... Cathode separator 40 ... Solid polymer electrolyte membrane 42 ... Anode feeder 42a ... Anode electrode catalyst layer 44 ... Cathode feeder 44a ... Cathode electrode catalyst layer 46 ... Anode Chamber 50 ... Water channel member 50a ... Water channel 54 ... Cathode chamber 60 ... Hydrogen channel member 60a ... Hydrogen channel 62, 86 ... Resin sheet member 64 ... Adhesive 70 ... Seal member

Claims (5)

An electrolyte membrane;
An anode feeder and a cathode feeder provided on both sides of the electrolyte membrane;
An anode separator disposed opposite to the anode power supply body and provided with an anode chamber in which oxygen is generated by electrolyzing supplied water;
A cathode separator disposed opposite to the cathode power supply body and provided with a cathode chamber in which hydrogen having a pressure higher than that of oxygen is generated by electrolysis of the water;
A plurality of high-pressure water electrolysis cells having a stack and a differential pressure type high-pressure water electrolysis apparatus fastened in the stacking direction,
On the outer periphery of the electrolyte membrane, an insulating reinforcing member having a compressive strength higher than that of the electrolyte membrane is disposed corresponding to a portion compressed by high pressure between the anode separator and the cathode separator by fastening,
The differential pressure type high-pressure water electrolysis apparatus, wherein a portion where the electrolyte membrane and the insulating reinforcing member overlap along the stacking direction is joined by an adhesive.   2. The differential pressure type high pressure water electrolysis apparatus according to claim 1, wherein the adhesive contains an epoxy group. 3.   3. The differential pressure type high pressure water electrolysis apparatus according to claim 1, wherein the adhesive is cured and has a thickness of 30 μm or more in the laminating direction. 4. Electrolytic device.   3. The differential pressure type high pressure water electrolysis apparatus according to claim 2, wherein the adhesive has a fluorine-based main skeleton.   5. The differential pressure type high pressure water electrolysis apparatus according to claim 1, wherein a seal member is overlapped at a portion where the electrolyte membrane and the insulating reinforcing member overlap each other. Differential pressure type high pressure water electrolyzer.

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