JP2022108381A - Ammonia decomposition apparatus and hydrogen gas production system - Google Patents

Abstract

To provide an ammonia decomposition apparatus capable of suppressing breakage of a hydrogen gas permeable membrane.SOLUTION: An ammonia decomposition device for decomposing ammonia gas by plasma comprises: an electrode plate to which an AC power source is connected; an insulating plate abutting on the electrode plate; an ammonia treatment section abutting on the insulating plate and forming a flow path of the ammonia gas, and decomposing the ammonia gas into hydrogen gas by plasma generated in the flow path by application of a voltage to the electrode plate; a hydrogen gas permeable membrane capable of the selective permeation of the hydrogen gas among the gases flowing through the flow path; a pressing member having a pressing surface for pressing a portion of the hydrogen gas permeable membrane opposed to the flow path from the back side opposite to the flow path and capable of passing the hydrogen gas; and a recovery section for recovering the hydrogen gas passed through the pressing member.SELECTED DRAWING: Figure 2

Description

The present invention relates to an ammonia decomposition apparatus and a hydrogen gas production system having the same.

Conventionally, as described in Patent Document 1, there is known an apparatus for decomposing ammonia into hydrogen gas and nitrogen gas by plasma.

Patent Literature 1 describes a fuel cell system equipped with a hydrogen generator. This hydrogen generator includes a dielectric in which a raw material gas channel is formed, an electrode arranged to face the back surface of the dielectric, a hydrogen separating film closing an opening of the raw gas channel, a hydrogen separating A frame-shaped spacer is provided between the membrane and the anode of the fuel cell. In this device, a dielectric barrier discharge is generated in a dielectric raw material gas flow path, whereby ammonia becomes an atmospheric pressure non-equilibrium plasma, and hydrogen is generated from the atmospheric pressure non-equilibrium plasma. Then, the generated hydrogen passes through the hydrogen separation membrane while diffusing and reaches the space on the fuel electrode side of the fuel cell.

JP 2018-125064 A

In the hydrogen generator in Patent Document 1, a thin film such as a palladium alloy is used as a hydrogen separation membrane. Therefore, when hydrogen generated in the source gas flow path of the dielectric passes through the hydrogen separation membrane, there is a problem that the hydrogen separation membrane is broken by the pressure of the hydrogen.

The present invention has been made in view of the above problems, and an object thereof is to provide an ammonia decomposition apparatus capable of suppressing breakage of a hydrogen gas permeable membrane and a hydrogen gas production system including the same. .

An ammonia decomposition apparatus according to one aspect of the present invention is an ammonia decomposition apparatus that decomposes ammonia gas with plasma, comprising: an electrode plate connected to an AC power supply; an insulating plate abutting the electrode plate; an ammonia processing section that abuts and forms a channel for the ammonia gas, and decomposes the ammonia gas into hydrogen gas by plasma generated in the channel by applying a voltage to the electrode plate; a hydrogen gas permeable membrane capable of selectively permeating said hydrogen gas among gases; A pressing member through which the hydrogen gas can pass, and a recovery unit that recovers the hydrogen gas that has passed through the pressing member.

According to this configuration, since the portion of the hydrogen gas permeable membrane that faces the flow path of the ammonia processing section is pressed from the back side by the pressing member, the hydrogen gas generated in the flow path passes through the hydrogen gas permeable membrane. During permeation, the hydrogen gas permeable membrane can be prevented from swelling on the side opposite to the channel. As a result, it is possible to prevent the hydrogen gas permeable membrane from breaking due to the pressure of the hydrogen gas, and to recover the hydrogen gas that has passed through the pressing member.

In the above ammonia decomposition apparatus, the pressing member includes a porous member having the pressing surface and a flow path for guiding the hydrogen gas that has permeated the porous member to the recovery unit, and is opposite to the hydrogen gas permeable membrane. and an elastic member that supports the porous member from the side.

According to this configuration, by supporting the porous member from the back side by the elastic member, the portion of the hydrogen gas permeable membrane facing the channel of the ammonia processing section can be more reliably held down.

In the above ammonia decomposition apparatus, the insulating plate may be made of ceramics and hold the electrode plate inside.

According to this configuration, the insulation around the electrode plate can be ensured more reliably.

In the above ammonia decomposition apparatus, the electrode plate may be positioned closer to the ammonia processing section than the center in the thickness direction inside the insulating plate.

According to this configuration, it is possible to suppress the occurrence of discharge on the surface of the insulating plate opposite to the ammonia-treated portion.

In the above ammonia decomposition apparatus, the electrode plate may consist of a single member.

In the above ammonia decomposition apparatus, the ammonia processing section may be a metal plate. The flow path may have a meandering shape including a penetrating portion that penetrates the metal plate in a thickness direction and a non-penetrating portion that partially remains in the thickness direction of the metal plate.

With this configuration, it is possible to stably hold the comb-shaped portion of the metal plate that defines the flow path. As a result, it is possible to suppress breakage of the hydrogen gas permeable membrane due to fluttering of the comb-shaped portion.

In the above ammonia decomposition apparatus, the non-penetrating portion may be provided at least at a bent portion of the flow path.

With this configuration, it is possible to stably hold the tip of the comb-shaped portion of the metal plate, which is particularly prone to instability.

In the above ammonia decomposition apparatus, the ammonia processing section may be a metal plate. The flow path includes a gas inlet that penetrates the metal plate in the thickness direction, a gas outlet that penetrates the metal plate in the thickness direction, a plurality of fine flow channels that connect the gas inlet and the gas outlet, may contain The microchannel may include a through portion that penetrates the metal plate in the thickness direction, and a non-penetration portion that partially remains in the thickness direction of the metal plate.

According to this configuration, by providing a plurality of fine flow paths, it is possible to secure a larger amount of ammonia gas to be processed. Further, since the fine channels include non-penetrating portions, the portions of the metal plate located between the fine channels can be stably held.

A hydrogen gas production system according to another aspect of the present invention includes a first ammonia decomposition device that receives ammonia gas from an ammonia supply source and decomposes the ammonia gas with a catalyst to generate hydrogen gas; a second ammonia decomposition device that receives the mixed gas containing ammonia gas and hydrogen gas discharged from the first ammonia decomposition device, decomposes the ammonia gas to further generate hydrogen gas, and recovers the hydrogen gas.

According to this configuration, after the ammonia gas is decomposed by the catalytic reaction, the remainder can be plasma decomposed. As a result, the amount of ammonia gas to be processed can be ensured, and the purity of hydrogen gas can be increased.

As is clear from the above description, according to the present invention, it is possible to provide an ammonia decomposition apparatus capable of suppressing breakage of the hydrogen gas permeable membrane and a hydrogen gas production system including the same.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows typically the structure of the hydrogen gas production system which concerns on Embodiment 1 of this invention. 1 is a longitudinal sectional view schematically showing the configuration of an ammonia decomposition apparatus according to Embodiment 1 of the present invention; FIG. FIG. 3 is a plan view schematically showing the configuration of the ammonia processing section in Embodiment 1 of the present invention. 4 is an enlarged view of area IV in FIG. 3; FIG. FIG. 5 is a cross-sectional view along the line segment VV in FIG. 4; Fig. 2 is a longitudinal sectional view schematically showing the configuration of an ammonia decomposition apparatus according to Embodiment 2 of the present invention; FIG. 5 is a schematic diagram for explaining the flow of hydrogen gas in the ammonia decomposition apparatus according to Embodiment 2 of the present invention; FIG. 3 is a longitudinal sectional view schematically showing the configuration of an ammonia decomposition apparatus according to Embodiment 3 of the present invention; FIG. 10 is a plan view schematically showing the configuration of an ammonia treatment section in Embodiment 4 of the present invention. It is a schematic diagram for describing other embodiments of the present invention. It is a schematic diagram for describing other embodiments of the present invention.

Hereinafter, an ammonia cracking apparatus and a hydrogen gas production system according to embodiments of the present invention will be described in detail based on the drawings.

(Embodiment 1)
First, the configuration of a hydrogen gas production system 100 according to Embodiment 1 of the present invention will be described based on FIG. The hydrogen gas production system 100 produces hydrogen gas G2 using ammonia gas G0 as a raw material gas. The use of the hydrogen gas G2 includes, but is not limited to, fuel cells. As shown in FIG. 1 , the hydrogen gas production system 100 mainly includes a first ammonia decomposition device 4 and a second ammonia decomposition device 1 .

The first ammonia decomposition device 4 receives the ammonia gas G0 from the ammonia supply source 9 and decomposes the ammonia gas G0 with a catalyst to generate hydrogen gas and nitrogen gas. The first ammonia decomposition device 4 is connected to the ammonia supply source 9 via the first gas supply line 5 and to the second ammonia decomposition device 1 via the second gas supply line 6 . A mixed gas G1 containing undecomposed ammonia gas, hydrogen gas and nitrogen gas is discharged from the first ammonia decomposition device 4 and supplied to the second ammonia decomposition device 1 via the second gas supply line 6 .

The second ammonia decomposition device 1 receives the mixed gas G1 discharged from the first ammonia decomposition device 4, decomposes the ammonia gas to further generate hydrogen gas G2, and recovers the hydrogen gas G2. Hereinafter, the configuration of the second ammonia decomposition device 1 (also simply referred to as "ammonia decomposition device 1") will be described in detail.

The ammonia decomposition apparatus 1 decomposes ammonia gas into hydrogen gas and nitrogen gas by plasma. FIG. 2 is a longitudinal sectional view of the ammonia decomposition device 1. FIG. As shown in FIG. 2, the ammonia decomposition apparatus 1 includes an electrode plate 10, an insulating plate 20, a flange 30, an ammonia processing section 40, a hydrogen gas permeable membrane 50, a pressing member 60, and a recovery section 70. Prepare the Lord.

The electrode plate 10 consists of a single plate member and is electrically connected to an AC power source 11 . The insulating plate 20 is a plate made of ceramics (insulating material) such as Al ₂ O ₃ and includes an upper surface 22 and a lower surface 21 . The insulating plate 20 is in contact with the electrode plate 10 and holds the electrode plate 10 inside in this embodiment. In other words, the electrode plate 10 is embedded inside the insulating plate 20 , and the entire periphery of the electrode plate 10 is electrically insulated by the insulating plate 20 . As shown in FIG. 2, the electrode plate 10 is parallel to the upper surface 22 and the lower surface 21, and is embedded substantially in the center of the insulating plate 20 in the radial direction. The insulating plate 20 may be made of an insulating material other than ceramics.

The insulating plate 20 is formed with a supply channel 23 through which the mixed gas G1 supplied to the ammonia processing unit 40 flows, penetrating the insulating plate 20 in the thickness direction, and discharged from the ammonia processing unit 40. A discharge channel 24 through which gas flows is formed so as to penetrate through the insulating plate 20 in the thickness direction. As shown in FIG. 2 , the electrode plate 10 is positioned between the supply channel 23 and the discharge channel 24 in the radial direction of the insulating plate 20 .

The flanges 30 sandwich the insulating plate 20 and include an upper flange 31 and a lower flange 32 . Both the upper flange 31 and the lower flange 32 are plates made of SUS and have a smaller diameter than the insulating plate 20 . The insulating plate 20 is sandwiched between the upper flange 31 and the lower flange 32 in the thickness direction.

The upper flange 31 includes an inner surface 31A that contacts the upper surface 22 of the insulating plate 20 and an outer surface 31B that faces the opposite side of the inner surface 31A. A plurality of annular grooves recessed toward the outer surface 31B are formed in the inner surface 31A, and seal members 33 such as O-rings are mounted in the annular grooves. Thereby, the airtightness between the upper surface 22 of the insulating plate 20 and the inner surface 31A of the upper flange 31 is ensured.

The upper flange 31 is formed with a supply passage 36 through which the mixed gas G1 supplied to the ammonia processing section 40 passes through the upper flange 31 in the thickness direction, and is discharged from the ammonia processing section 40. A discharge passage 37 through which gas flows is formed so as to penetrate the upper flange 31 in the thickness direction. As shown in FIG. 2 , the supply channel 36 of the upper flange 31 is formed between annular grooves in which the seal member 33 is accommodated, and communicates with the supply channel 23 of the insulating plate 20 . Similarly, the discharge channel 37 of the upper flange 31 is formed between the annular grooves in which the seal member 33 is accommodated and communicates with the discharge channel 24 of the insulating plate 20 . A portion where the supply channel 36 is opened to the outer surface 31B side is a gas inlet 36A, and a portion where the discharge channel 37 is opened to the outer surface 31B side is a gas outlet 37A.

The lower flange 32 includes an inner surface 32A that contacts the lower surface 21 of the insulating plate 20, and an outer surface 32B that faces away from the inner surface 32A. Similar to the upper flange 31, the inner surface 32A is formed with an annular groove recessed toward the outer surface 32B side, and a seal member 34 such as an O-ring is mounted in the annular groove. This ensures airtightness between the lower surface 21 of the insulating plate 20 and the inner surface 32A of the lower flange 32 . Although the lower flange 32 is grounded in the present embodiment, the location to be grounded is not limited to this.

The lower flange 32 is formed with a large-diameter groove 35, which is a space recessed from the inner surface 32A toward the outer surface 32B, and a small-diameter groove 35A, which communicates with the large-diameter groove 35 and has a smaller diameter than the large-diameter groove 35. ing. The small-diameter groove 35A is concentric with the large-diameter groove 35 and formed closer to the outer surface 32B than the large-diameter groove 35 is. Both the large-diameter groove 35 and the small-diameter groove 35A are formed radially inward of the annular groove in which the seal member 34 is accommodated.

As shown in FIG. 2, the ammonia processing section 40, the hydrogen gas permeable membrane 50, and the pressing member 60 are accommodated in the large-diameter groove 35 in an overlapping state from above. The inner diameter of the large-diameter groove 35 is substantially the same as the outer diameters of the ammonia-treated portion 40 and the pressing member 60 , and each side surface of the ammonia-treated portion 40 and the pressing member 60 abuts the inner surface of the large-diameter groove 35 .

The lower flange 32 is provided with a stepped surface 39 connecting the inner surface of the large diameter groove 35 and the inner surface of the small diameter groove 35A. The stepped surface 39 is an annular plane parallel to the inner surface 32A and the outer surface 32B, and the outer peripheral portion of the pressing member 60 is placed on the stepped surface 39 . An annular groove recessed toward the outer surface 32B is formed in the stepped surface 39, and a seal member 38 such as an O-ring is mounted in the annular groove. This ensures airtightness between the lower surface of the pressing member 60 and the stepped surface 39 .

The ammonia processing section 40 is in contact with the lower surface 21 of the insulating plate 20 and has a channel R1 for ammonia gas. The ammonia processing unit 40 decomposes the ammonia gas into hydrogen gas and nitrogen gas by plasma generated in the flow path R1 by applying voltage to the electrode plate 10 . The ammonia treatment part 40 is a metal plate made of, for example, SUS, and includes an upper surface 40A in contact with the lower surface 21 of the insulating plate 20 and a lower surface 40B in contact with the hydrogen gas permeable film 50 .

Here, the detailed configuration of the ammonia processing section 40 will be described with reference to FIGS. 3 to 5. FIG. FIG. 3 is a plan view of the ammonia processing section 40. FIG. FIG. 4 is an enlarged view of area IV in FIG. FIG. 5 is a cross-sectional view along line segment VV in FIG.

As shown in FIG. 3, the ammonia gas flow path R1 is formed to connect the gas inlet 43 and the gas outlet 44, and has a meandering shape including a plurality of through portions 41 and a plurality of non-penetrating portions 42. have. Specifically, the penetrating portions 41 and the non-penetrating portions 42 are alternately formed along the flow path R1, and the non-penetrating portions 42 are provided at each bent portion of the flow path R1. The flow path R1 is formed by, for example, etching, laser processing, cutting, or the like.

The gas inlet 43 has a semicircular shape in plan view and communicates with the supply channel 23 ( FIG. 2 ) of the insulating plate 20 . The gas outlet 44 has a semicircular shape in a plan view opposite to the gas inlet 43 and communicates with the discharge channel 24 ( FIG. 2 ) of the insulating plate 20 . The penetrating portion 41 has a rectangular shape in plan view, and is formed in plurality at predetermined intervals in a direction perpendicular to the length direction of the penetrating portion 41 (horizontal direction in FIG. 3). Non-penetrating portions 42 are formed between adjacent penetrating portions 41 .

The gas inlet 43, the gas outlet 44, and the through portion 41 are all formed to penetrate the metal plate in the thickness direction. In other words, the gas inlet 43, the gas outlet 44, and the through portion 41 are open to both the upper surface 40A side and the lower surface 40B side (FIG. 2) of the ammonia processing section 40. As shown in FIG.

On the other hand, the non-penetrating portion 42 is formed by processing the metal plate so as not to penetrate the metal plate in the thickness direction and to leave a part of the metal plate in the thickness direction. Specifically, as shown in FIG. 5 , a thin portion 42A of the metal plate is left in the non-penetrating portion 42 . Therefore, the non-penetration portion 42 is open to the upper surface 40A side of the ammonia treated portion 40, but is not open to the lower surface 40B side.

The ammonia processing section 40 includes a plate body 46 and a plurality of comb sections 45 . As shown in FIG. 3 , the comb portion 45 has a rectangular shape in plan view parallel to the penetrating portions 41 and is provided between adjacent penetrating portions 41 . The comb portion 45 includes a base end 45B directly connected to the plate main body 46 and a distal end 45A connected to the plate main body 46 via the thin portion 42A (FIG. 5).

The hydrogen gas permeable membrane 50 ( FIG. 2 ) is capable of selectively permeating the hydrogen gas G2 among the gases flowing through the flow path R1, and is attached to the lower surface 40B of the ammonia processing section 40 . The hydrogen gas permeable film 50 is made of, for example, a Pd--Cu alloy, and is a thin metal foil that covers the entire flow path R1 (one-dot chain line in FIG. 3). As shown in FIG. 2, the hydrogen gas permeable membrane 50 includes a portion 51 facing the flow path R1 (a portion blocking the gas inlet 43, the gas outlet 44 and the through portion 41 from the lower surface 40B side). The hydrogen gas permeable membrane 50 is a rolled metal thin film.

The pressing member 60 has a pressing surface 61 that presses a portion 51 of the hydrogen gas permeable membrane 50 facing the flow path R1 from the back side opposite to the flow path R1, and allows the hydrogen gas G2 to pass therethrough. The pressing surface 61 is in surface contact with the entire lower surface of the hydrogen gas permeable membrane 50 (the surface opposite to the ammonia treatment section 40), and presses the entire lower surface upward with a substantially uniform force. The pressing member 60 in this embodiment includes a planar porous member 62 including a pressing surface 61 and a ring plate 64 surrounding the porous member 62 . As the porous member 62, for example, mesh-shaped resin or metal, punching metal, porous metal, porous ceramics (for example, porous alumina), or the like can be used. The ring plate 64 is a dense metal member (non-porous member) through which the hydrogen gas G2 does not permeate. A contact portion between the upper surface of the ring plate 64 and the lower surface of the hydrogen gas permeable membrane 50 serves as a seal portion, and a contact portion between the lower surface of the ring plate 64 and the seal member 38 serves as a seal portion. As a result, it is possible to suppress the ammonia gas from entering from the outer peripheral side of the hydrogen gas permeable membrane 50 and leaking to the recovery section 70 side.

The pressing member 60 is a plate having substantially the same diameter as the ammonia processing section 40, and has a size that covers the entire flow path R1 in plan view. That is, the pressing surface 61 faces the entire flow path R1 (the region including the gas inlet 43, the gas outlet 44, the penetrating portion 41 and the non-penetrating portion 42) with the hydrogen gas permeable membrane 50 interposed therebetween. Therefore, the pressing surface 61 presses the entire portion 51 of the hydrogen gas permeable membrane 50 facing the flow path R1 from the back side opposite to the flow path R1. In addition, as shown in FIG. 2, a gap (small-diameter groove 35A) is left below the pressing member 60. As shown in FIG.

The recovery part 70 is a part that recovers the hydrogen gas G2 that has passed through the pressing member 60 . As shown in FIG. 2, the recovery portion 70 is a through hole formed in the lower central portion of the lower flange 32 and communicates with the small-diameter groove 35A.

Next, the manufacturing process of the hydrogen gas G2 by the hydrogen gas manufacturing system 100 will be described.

As shown in FIG. 1 , first, ammonia gas G0 is supplied from the ammonia supply source 9 to the first ammonia decomposition device 4 through the first gas supply line 5 . In the first ammonia decomposition device 4, part of the ammonia gas G0 is decomposed into hydrogen gas and nitrogen gas by catalytic reaction. Then, a mixed gas G1 containing hydrogen gas, nitrogen gas and undecomposed ammonia gas is supplied to the second ammonia decomposition device 1 through the second gas supply line 6.

As shown in FIG. 2, the mixed gas G1 flows into the ammonia decomposition apparatus 1 from the gas inlet 36A, flows through the supply channel 36 of the upper flange 31 and the supply channel 23 of the insulating plate 20 in order, and then undergoes ammonia treatment. It is fed into section 40 . The mixed gas G1 flows into the flow path R1 from the gas inlet 43 (FIG. 3) and flows toward the gas outlet 44 meandering through the flow path R1.

On the other hand, by applying a predetermined voltage to the electrode plate 10 from the AC power source 11 (FIG. 2), plasma is generated in the flow path R1 (between the electrode plate 10 and the hydrogen gas permeable membrane 50). Ammonia gas contained in the mixed gas G1 is decomposed into hydrogen gas G2 and nitrogen gas by this plasma. The partial pressure of the hydrogen gas G2 is, for example, approximately atmospheric pressure. Of the gases flowing through the flow path R1, only the hydrogen gas G2 permeates the hydrogen gas permeable membrane 50, and after passing through the pressing member 60, is taken out of the ammonia decomposition apparatus 1 from the recovery section . On the other hand, the nitrogen gas and the undecomposed ammonia gas flow out of the ammonia processing unit 40 from the gas outlet 44 (FIG. 3) and flow through the discharge channel 24 (FIG. 2) of the insulating plate 20 and the discharge channel of the upper flange 31. 37, the gas is taken out of the ammonia decomposition apparatus 1 through a gas outlet 37A (gas G3).

Next, the effects of the ammonia decomposition device 1 will be described.

As described above, the hydrogen gas G2 generated by plasma decomposition in the ammonia processing section 40 permeates the hydrogen gas permeable membrane 50 and is taken out of the ammonia decomposition apparatus 1 . Here, since the hydrogen gas permeable membrane 50 is a thin metal foil, there is concern that it may be broken by the wind pressure of the hydrogen gas G2. In contrast, in the ammonia decomposition apparatus 1 according to the present embodiment, a pressing member 60 having a pressing surface 61 that presses the portion 51 (FIG. 2) of the hydrogen gas permeable membrane 50 facing the flow path R1 from the back side is arranged. Thereby, it is possible to suppress the hydrogen gas permeable membrane 50 from expanding downward due to the wind pressure of the hydrogen gas G2. Therefore, it is possible to prevent the hydrogen gas permeable membrane 50 from breaking due to the wind pressure of the hydrogen gas G2.

(Embodiment 2)
Next, the configuration of the ammonia decomposition device 2 according to Embodiment 2 of the present invention will be described with reference to FIGS. 6 and 7. FIG. The ammonia decomposition apparatus 2 according to Embodiment 2 basically has the same configuration and effects as the ammonia decomposition apparatus 1 according to Embodiment 1, but differs in the configuration of the pressing member 60 . Only points different from the first embodiment will be described below. In addition, in FIG.6 and FIG.7, the same referential mark is attached|subjected to the component corresponding to Embodiment 1, and the description is abbreviate|omitted.

As shown in FIG. 6, the pressing member 60 in the second embodiment supports the porous member 62 from the side opposite to the hydrogen gas permeable membrane 50, in addition to the porous member 62 and the ring plate 64 surrounding the porous member 62. It further includes an elastic member 63 for The elastic member 63 is made of, for example, a rubber plate, and has a hole 63A (flow path) formed in the center in the radial direction for guiding the hydrogen gas G2 that has permeated the porous member 62 to the recovery section 70 . As shown in FIG. 6, the porous member 62 and ring plate 64 are housed in the large diameter groove 35, and the elastic member 63 is housed in the small diameter groove 35A. The elastic member 63 is compressed in the thickness direction, and the porous member 62 is pressed against the lower surface of the hydrogen gas permeable membrane 50 by the reaction force. The outer surface of the porous member 62 (the surface in contact with the inner surface of the ring plate 64) is flush with the outer surface of the elastic member 63. As shown in FIG.

FIG. 7 schematically shows how the hydrogen gas G2 that has permeated the hydrogen gas permeable membrane 50 passes through the inside of the pressing member 60. As shown in FIG. As shown in FIG. 7, the hydrogen gas G2 that permeates the hydrogen gas permeable membrane 50 flows toward the center in the radial direction inside the porous member 62 . Then, the hydrogen gas G2 gathered in the radial center of the porous member 62 is taken out of the ammonia decomposition device 2 (FIG. 6) through the holes 63A of the elastic member 63. As shown in FIG.

As described above, according to the ammonia decomposition apparatus 2 according to the present embodiment, by adopting the laminate of the porous member 62 and the elastic member 63, the porous member 62 can be pressed from the back side by the elastic member 63. . As a result, the portion 51 of the hydrogen gas permeable membrane 50 that faces the flow path R1 can be more reliably pressed by the pressing surface 61, and breakage of the hydrogen gas permeable membrane 50 can be more reliably suppressed. In addition, as described in Embodiment 1, the elastic member is not an essential component in the ammonia decomposition apparatus of the present invention. When the elastic member is not employed as in the first embodiment, the thickness and the large diameter of the pressing member 60 are adjusted so that the portion 51 of the hydrogen gas permeable membrane 50 facing the flow path R1 is reliably pressed by the pressing surface 61. It is preferable to adjust the depth and the like of the groove 35 appropriately.

(Embodiment 3)
Next, the configuration of the ammonia decomposition device 3 according to Embodiment 3 of the present invention will be described with reference to FIG. The ammonia decomposition device 3 according to Embodiment 3 basically has the same configuration and effects as the ammonia decomposition device 2 according to Embodiment 2, but differs in the configuration of the pressing member 60 . Only points different from the second embodiment will be described below. In addition, in FIG. 8, the same reference numerals are given to the components corresponding to the second embodiment, and the description thereof is omitted.

The elastic member 63B in the third embodiment is composed of a spring and arranged in a compressed state in the small-diameter groove 35A. The porous member 62 is biased upward by the spring force of the elastic member 63B. holding down.

As described above, in Embodiment 3, instead of the rubber used in Embodiment 2, a member having a gap through which hydrogen gas can pass over the entire member such as a spring (a gap through which hydrogen gas can pass without forming a hole) member) as an elastic member, the hydrogen gas G2 after passing through the porous member 62 can flow more easily to the recovery section 70 . Therefore, retention of the hydrogen gas G2 within the lower flange 32 can be suppressed. Metal cotton or the like may be employed as the elastic member 63B instead of the spring.

(Embodiment 4)
Next, the configuration of the ammonia decomposition apparatus according to Embodiment 4 of the present invention will be described with reference to FIG. The ammonia decomposition apparatus according to Embodiment 4 basically has the same configuration and effects as the ammonia decomposition apparatus 1 according to Embodiment 1, but differs in the configuration of the ammonia processing section. Only points different from the first embodiment will be described below. In addition, in FIG. 9, the same reference numerals are given to the components corresponding to the first embodiment, and the description thereof is omitted.

FIG. 9 is a plan view of the ammonia processing section 40 in Embodiment 4. FIG. The channel R1 of the ammonia processing section 40 includes a gas inlet 43, a gas outlet 44, and a plurality of (two in the example of FIG. 9) fine channels R2 connecting the gas inlet 43 and the gas outlet 44. Both the gas inlet 43 and the gas outlet 44 pass through the metal plate of the ammonia processing section 40 in the thickness direction.

The fine flow channel R2 has a meandering shape including a penetrating portion 47 and a non-penetrating portion 48, and is formed along each other. The penetrating portion 47 is formed to penetrate the metal plate in the thickness direction, while the non-penetrating portion 48 is formed so as to partially leave the metal plate in the thickness direction (including the thin portion). ing. As shown in FIG. 9, the non-penetrating portions 48 are provided at both ends of the microchannel R2 (portions connected to the gas inlet 43 and the gas outlet 44) and at each bent portion of the microchannel R2. may be further provided in

The ammonia processing section 40 includes a plate body 46 and a meandering section 49 . The meandering portion 49 is a portion sandwiched between the two fine flow paths R2 and is connected to the plate main body 46 via the non-penetrating portion 48 (thin portion).

In the ammonia decomposition apparatus according to the present embodiment, by providing a plurality of fine flow paths R2, it is possible to secure a larger amount of ammonia gas to be processed. By providing the non-penetrating portion 48 in each fine channel R2, the meandering portion 49 sandwiched by the fine channels R2 can be stably held with respect to the plate main body 46. FIG. In addition, in the ammonia decomposition devices 2 and 3 according to the second and third embodiments, a plurality of fine channels R2 may be provided.

It should be understood that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims. Therefore, the following embodiments are also included in the scope of the present invention.

In Embodiment 1, the pressing member 60 may be a porous member and an elastic member. In this case, for example, steel wool, sponge, or the like can be used as the material of the pressing member 60 .

The hydrogen gas permeable membrane 50 may be grounded instead of the lower flange 32 .

The ammonia treatment part is not limited to being made of a metal plate, and may be made of other materials such as SiO ₂ . However, by using a metal plate, the thickness of the insulating plate 20 can be reduced, and the dielectric loss can be suppressed. Further, the flow path R1 is not limited to a meandering shape, and may be formed in other shapes such as a linear shape.

In Embodiment 1, the non-penetrating portion 42 may also be provided in a portion of the flow path R1 other than the curved portion.

The electrode plate 10 is not limited to being held inside the insulating plate 20, and the electrode plate 10 may be placed on the insulating plate 20 as shown in FIG. In this case, insulation around the electrode plate 10 is ensured by a method such as resin molding 80 .

As shown in FIG. 11 , the electrode plate 10 may be located inside the insulating plate 20 closer to the ammonia treated portion 40 (lower surface 21 side) than the center in the thickness direction. Thereby, when a voltage is applied to the electrode plate 10, the occurrence of discharge on the upper surface 22 of the insulating plate 20 can be suppressed.

1, 2, 3 Ammonia decomposition device (second ammonia decomposition device)
4 First Ammonia Decomposition Device 9 Ammonia Supply Source 10 Electrode Plate 11 AC Power Supply 20 Insulating Plate 40 Ammonia Processing Part 41, 47 Penetrating Part 42, 48 Non-Penetrating Part 43 Gas Inlet 44 Gas Outlet 50 Hydrogen Gas Permeable Membrane 60 Pressing Member 61 Pressing Surface 62 Porous member 63, 63B Elastic member 63A Hole (channel)
70 recovery unit 100 hydrogen gas production system G0 ammonia gas G1 mixed gas G2 hydrogen gas R1 channel R2 fine channel

Claims (9)

An ammonia decomposition apparatus that decomposes ammonia gas with plasma,
an electrode plate to which an AC power supply is connected;
an insulating plate in contact with the electrode plate;
an ammonia processing unit that is in contact with the insulating plate and has a flow path for the ammonia gas, and decomposes the ammonia gas into hydrogen gas by plasma generated in the flow path by voltage application to the electrode plate;
a hydrogen gas permeable membrane selectively permeable to the hydrogen gas among the gases flowing through the channel;
a pressing member having a pressing surface that presses a portion of the hydrogen gas permeable membrane facing the flow path from a back side opposite to the flow path, through which the hydrogen gas can pass;
and a recovery unit configured to recover the hydrogen gas that has passed through the pressing member. The holding member is
a porous member having the pressing surface;
2. The method according to claim 1, further comprising: an elastic member that supports the porous member from a side opposite to the hydrogen gas permeable membrane, and a channel that guides the hydrogen gas that has permeated the porous member to the recovery unit. of ammonia decomposition equipment. 3. The ammonia decomposition apparatus according to claim 1, wherein said insulating plate is made of ceramics and holds said electrode plate inside. 4. The ammonia decomposition apparatus according to claim 3, wherein the electrode plate is positioned closer to the ammonia processing section than the center in the thickness direction inside the insulating plate. 5. The ammonia decomposition apparatus according to any one of claims 1 to 4, wherein said electrode plate is made of a single member. The ammonia treatment part is a metal plate,
6. The flow path according to any one of claims 1 to 5, wherein the flow path has a meandering shape including a penetrating portion that penetrates the metal plate in a thickness direction and a non-penetrating portion that partially remains in the thickness direction of the metal plate. 2. The ammonia decomposition apparatus according to item 1. 7. The ammonia decomposition apparatus according to claim 6, wherein said non-penetrating portion is provided at least at a curved portion of said flow path. The ammonia treatment part is a metal plate,
The flow path includes a gas inlet that penetrates the metal plate in the thickness direction, a gas outlet that penetrates the metal plate in the thickness direction, a plurality of fine flow channels that connect the gas inlet and the gas outlet, including
6. The microchannel according to any one of claims 1 to 5, wherein the microchannel includes a penetrating portion penetrating the metal plate in a thickness direction and a non-penetrating portion remaining a part of the metal plate in the thickness direction. 10. Ammonia decomposing apparatus according to claim 1. a first ammonia decomposition device that receives ammonia gas from an ammonia supply source and decomposes the ammonia gas with a catalyst to generate hydrogen gas;
9. The ammonia decomposition apparatus according to any one of claims 1 to 8, wherein a mixed gas containing ammonia gas and hydrogen gas discharged from the first ammonia decomposition apparatus is received, and the ammonia gas is decomposed into hydrogen gas. and a second ammonia cracking device for further generating and recovering hydrogen gas;
A hydrogen gas production system comprising:

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