JP6636302B2 - Hydrogen separation device - Google Patents

Description

  The present invention relates to a hydrogen separator having a hydrogen separator for separating hydrogen from a gas containing hydrogen.

  Conventionally, as a hydrogen separation device for separating hydrogen from a hydrogen-containing gas, a hydrogen separator having a plurality of through-holes formed in a columnar porous support, and a hydrogen-permeable metal film formed on an inner peripheral surface of each through-hole. There has been proposed a device provided with (for example, see Patent Documents 1 and 2). The hydrogen-permeable metal film is, for example, a palladium film formed of palladium (Pd). The palladium film has a property of transmitting hydrogen from a high hydrogen partial pressure side to a low hydrogen partial pressure side when a differential pressure of hydrogen is generated on both sides of the palladium film. More specifically, first, on the surface of the palladium film on the high hydrogen partial pressure side, hydrogen molecules are dissociated into hydrogen atoms and occluded in palladium. The hydrogen atoms occluded in the palladium diffuse into the palladium, and bond with other hydrogen atoms on the surface of the palladium film on the low hydrogen partial pressure side to become hydrogen molecules again. As a result, high-purity hydrogen is separated from the hydrogen-containing gas.

JP-A-8-38863 (FIG. 1 etc.) WO2012 / 128217 (FIGS. 1, 2 etc.)

  However, in the prior arts described in Patent Literatures 1 and 2, the porous support is thick, and the distance between the outer peripheral surface of the porous support and the inner peripheral surface of the through hole is large. The pressure loss when passing through the body increases. As a result, the hydrogen-containing gas is passed from the outside of the porous support toward the hydrogen-permeable metal film formed on the inner peripheral surface of the through-hole, and the hydrogen that has passed through the hydrogen-permeable metal film is guided into the through-hole. At this time, it becomes difficult for the hydrogen-containing gas to reach the hydrogen-permeable metal film at the center of the porous support. For this reason, there is a problem that the hydrogen permeation amount per unit area of the hydrogen permeable metal film is reduced. Further, when hydrogen-containing gas is introduced into the through-holes and hydrogen permeated through the hydrogen-permeable metal membrane is guided to the outside of the porous support, hydrogen permeated through the hydrogen-permeable metal membrane is applied to the porous support. It is difficult to reach the outside. Therefore, also in this case, there is a problem that the hydrogen permeation amount per unit area of the hydrogen-permeable metal film is reduced.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a hydrogen separation device capable of efficiently separating hydrogen by reducing a pressure loss when a gas passes through a porous support. Is to provide.

As means (means 1) for solving the above-mentioned problems, a plurality of hydrogen separators each having a hydrogen-permeable metal membrane formed on a cylindrical porous support, and gas passing between the adjacent hydrogen separators are provided. A holding member that holds at least one end of the plurality of hydrogen separators in a state where the plurality of hydrogen separators are separated from each other so as to have a space, wherein the holding member has a concave portion on an upper surface. Having a plurality of holding recesses for holding an end of the hydrogen separator on the inner bottom surface of the recess, wherein the plurality of hydrogen separators are located between an inner peripheral surface and an outer peripheral surface of the porous support. Hydrogen separation characterized by being laminated to the holding member via a seal member that disables the passage of the gas, and a plurality of the holding members in which the plurality of hydrogen separation bodies are arranged in a straight line. There is a device.

  Therefore, according to the invention described in the means 1, a space through which gas passes is provided between the adjacent hydrogen separators. Moreover, unlike the conventional structure in which a plurality of through-holes are provided in a columnar porous support (so-called lotus root structure), the hydrogen separator has a plurality of tubes (tubular porous supports) independent of each other. Due to this structure, the porous support which becomes a resistance when gas passes therethrough can be formed relatively thin. From the above, it is possible to reduce the pressure loss when the gas passes through the inside of the hydrogen separation device. As a result, when gas is allowed to pass between the inner peripheral surface and the outer peripheral surface of the porous support, hydrogen contained in the gas easily permeates the hydrogen-permeable metal membrane formed on the porous support. Therefore, the amount of permeated hydrogen per unit area of the hydrogen-permeable metal film is not easily reduced. Therefore, it is possible to efficiently separate hydrogen using the hydrogen separation device.

The hydrogen separator provided in the hydrogen separator has a hydrogen-permeable metal membrane formed on a porous support. The porous support has a cylindrical shape (for example, a cylindrical shape, an elliptical cylindrical shape, a triangular cylindrical shape, a rectangular cylindrical shape, and the like). Here, examples of the material for forming the porous support include alumina (Al ₂ O ₃ ), yttria-stabilized zirconia (YSZ), magnesia, ceria, doped ceria, and a mixture thereof.

  The hydrogen-permeable metal membrane is formed on a cylindrical porous support. The hydrogen-permeable metal membrane may be a surface film formed on the outer peripheral surface of the porous support, or may be an inner film formed on the inner peripheral surface of the porous support. Alternatively, the inner membrane may be an inner membrane filled in the porous pores of the porous support. Here, as a material for forming the hydrogen-permeable metal film, for example, palladium (Pd), an alloy of palladium (specifically, Pd-Ag, Pd-Cu, Pd-Au), and the like can be given. When the hydrogen separation device is used at a high temperature (for example, 450 ° C. or higher), Pd—Ag is particularly preferably used.

  The holding member provided in the hydrogen separation device holds at least one end of the plurality of hydrogen separators. Here, as a material for forming the holding member, for example, ceramic or the like can be used. Preferred examples of such ceramics include alumina, aluminum nitride, silicon nitride, boron nitride, verilia, mullite, low-temperature fired glass ceramics, glass ceramics, and the like. Note that the holding member may include a holding recess for holding an end of the hydrogen separator. With this configuration, since the end of the hydrogen separator is inserted into the holding recess provided in the holding member, the hydrogen separator can be positioned accurately and easily. Further, by providing the holding recess, the gap between the end of the hydrogen separator and the recess, that is, the gap filled with the sealing material can be reduced. As a result, the amount of the sealing material used can be reduced. In particular, when the thermal expansion coefficient of the sealing material is different from the thermal expansion coefficients of the hydrogen separator and the holding member, cracks and the like due to the difference in thermal expansion are less likely to occur.

  In addition, the plurality of hydrogen separators are joined to the holding member via a seal member that prevents passage of gas between the inner peripheral surface and the outer peripheral surface of the porous support. Here, the sealing material is not particularly limited. For example, the sealing material may include at least one material of glass, glass ceramic, crystallized glass, and a composite material of glass and ceramic. In particular, the sealing material is preferably glass. In this case, for example, since the sealing material can be formed only by supplying the molten glass, gas sealing by the sealing material can be easily performed.

Further, a brazing material, an inorganic adhesive, or the like can be used as the sealing material. When the sealing material is a brazing material, the brazing material may contain a noble metal. Examples of the noble metal contained in the brazing material include gold (Au), silver (Ag), platinum (Pt), and the like. For example, when the noble metal contained in the brazing material is silver, the brazing material is a mixture of silver and an oxide, specifically, Ag-Al ₂ O ₃ , Ag-CuO, Ag-TiO ₂ , Ag —Cr ₂ O ₃ , Ag—SiO _{2 and the} like. Further, as the brazing material, a known brazing material such as an alloy of silver and another metal, specifically, Ag-Ge-Cr, Ag-Ti, Ag-Al, Ag-Pd, or Ag-Cu is used. You can also. On the other hand, when the sealing material is an inorganic adhesive, examples of the inorganic adhesive include a ceramic adhesive, a glass adhesive, and a cement adhesive. In particular, silica having a heat resistance of about 1200 ° C. -It is preferable to use an alumina-based inorganic adhesive.

  Further, the hydrogen separation device is configured by stacking a plurality of holding members in which a plurality of hydrogen separators are arranged on a straight line. Here, the adjacent holding members may be joined to each other via a sealing material. With this configuration, it is not necessary to prepare a material different from the sealing material when joining the holding members. Therefore, the number of materials required for manufacturing the hydrogen separation device is reduced, and the cost of the hydrogen separation device can be reduced. In addition, since the number of stacked layers can be easily increased, a hydrogen separator having a high degree of integration of the hydrogen separator can be easily realized.

  The hydrogen separation device may include a connection flow path for connecting two or more hydrogen separation bodies. In this way, when extracting hydrogen gas from the hydrogen separator, the number of hydrogen outlets can be reduced and the connection structure with the outside can be simplified, thereby facilitating installation. When hydrogen gas is introduced into the hydrogen separator, the number of hydrogen inlets can be reduced.

  Further, the plurality of holding members in which the plurality of hydrogen separators are arranged on a straight line may be stacked in at least one of the vertical direction, the horizontal direction, and the depth direction. By doing so, the number of hydrogen separators provided in the hydrogen separator can be increased. As a result, hydrogen is simultaneously separated from many hydrogen separators, so that a large amount of hydrogen can be obtained efficiently.

FIG. 2 is a perspective view showing a hydrogen separation device according to the first embodiment. The side view showing a hydrogen separation device. FIG. 4 is a plan view showing an integrated body (holding member). The front view which shows a hydrogen separator. Explanatory drawing which shows the usage method of the hydrogen separation apparatus in 1st Embodiment. The perspective view showing the hydrogen separation device in a 2nd embodiment. FIG. 4 is a plan view showing an integrated body (holding member). Explanatory drawing which shows the usage method of the hydrogen separation apparatus in 2nd Embodiment. Explanatory drawing which shows the other usage of the hydrogen separation apparatus in 1st Embodiment. Explanatory drawing which shows the other usage of the hydrogen separation apparatus in 2nd Embodiment. FIG. 3 is a perspective view showing a hydrogen separator in which an integrated body (holding member) is stacked in a lateral direction. The perspective view showing the hydrogen separation device in which the accumulation body (holding member) was laminated in the depth direction. FIG. 4 is a perspective view showing a hydrogen separator in which an integrated body (holding member) is stacked in a vertical direction, a horizontal direction, and a depth direction. FIG. 3 is a perspective view showing a hydrogen separator in which an integrated body (holding member) is stacked in a lateral direction. The perspective view showing the hydrogen separation device in other embodiments. The side view showing a hydrogen separation device. The perspective view showing the hydrogen separation device in other embodiments.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.

  As shown in FIGS. 1 and 2, the hydrogen separation device 1 of the present embodiment is a module formed by stacking a plurality of tubes 10 (hydrogen separators) in a vertical direction. The hydrogen separator 1 has a substantially rectangular parallelepiped shape having a width of 24 mm × a depth of 35 mm × a height of 10 mm. In the present embodiment, for convenience of description, the hydrogen separator 1 in which the integrated bodies 10 are stacked in three stages is illustrated.

  As shown in FIGS. 1 to 3, each integrated body 10 includes ten tubes 11 having a cylindrical shape, and a pair of holding members 21 and 22 having a rectangular band shape in a plan view. The two holding members 21 and 22 are arranged in parallel with each other. The tubes 11 are arranged on the holding members 21 and 22 in a straight line and at equal pitch. The tubes 11 are arranged in parallel with each other, and are arranged orthogonal to the holding members 21 and 22. The two holding members 21 and 22 hold both ends of each tube 11 in a state where the tubes 11 are separated from each other. More specifically, the holding member 21 holds the first end (the left end in FIG. 3) of each tube 11, and the holding member 22 holds the second end (the right end in FIG. 3) of each tube 11. are doing. As a result, a space A1 (see FIG. 3) through which the gas passes is generated between the adjacent tubes 11. In the present embodiment, for convenience of explanation, a structure in which ten tubes 11 are arranged on the holding members 21 and 22 is illustrated, but 20 tubes are arranged in an actual holding member.

As shown in FIGS. 1 to 3, the holding members 21 and 22 of the present embodiment have a substantially rectangular parallelepiped shape of 24 mm wide × 3 mm deep × 3 mm high. The holding members 21 and 22 have a member upper surface 23 and a member rear surface 24 and are made of ceramic such as alumina (Al ₂ O ₃ ). The holding members 21 and 22 each have one concave portion 25 formed on the upper surface 23 of the member. In the holding members 21 and 22, a plurality of holding recesses 27 are arranged at equal intervals on the inner bottom surface 26 of the recess 25. Each holding recess 27 has a semicircular shape when viewed from the depth direction of the holding members 21 and 22, and extends along the width direction of the holding members 21 and 22. The length of each holding recess 27 is equal to the depth of the holding members 21 and 22. Each of the holding recesses 27 holds an end of the tube 11 by inserting an end (a first end or a second end) of the tube 11.

  As shown in FIGS. 1 and 2, a plate member 28 is disposed on the upper surface 23 of the uppermost holding members 21 and 22. The plate member 28 of the present embodiment is in the shape of a strip having a width of 24 mm × a depth of 3 mm × a thickness of 1.0 mm. The plate member 28 is made of the same material (ceramic such as alumina) as the holding members 21 and 22.

  As shown in FIGS. 1 to 4, each tube 11 has heat resistance (300 ° C. to 400 ° C. in the present embodiment), and is formed by forming a hydrogen-permeable metal film 13 on a porous support 12. Become. The porous support 12 has a cylindrical shape with a length of 35 mm and an outer diameter of 2 mm, and has an inner peripheral surface 14 and an outer peripheral surface 15. Therefore, the porous support 12 is provided with a through-hole 16 having a circular cross section penetrating the porous support 12 in the length direction (axial direction). The porous support 12 of the present embodiment is a porous ceramic support made of alumina. The porous support 12 has a porosity of 20% or more and 60% or less, a pore diameter of 0.1 μm or more and 100 μm or less, and has a gas permeable structure. That is, the porous support 12 has a function of supporting the hydrogen permeable metal film 13 while having air permeability.

  On the outer peripheral surface 15 of the porous support 12, an intermediate layer (not shown) is formed. The intermediate layer is a protective layer that covers the entire outer peripheral surface 15 and protects the porous support 12. Note that the intermediate layer of the present embodiment is a thin film formed of alumina, and has a thickness of 5 μm or more and 100 μm or less. The intermediate layer may be formed of yttria-stabilized zirconia (YSZ).

  As shown in FIGS. 1 to 4, a hydrogen-permeable metal film 13 is formed on the outer peripheral surface of the intermediate layer. That is, the hydrogen-permeable metal film 13 is a surface film formed on the outer peripheral surface 15 of the porous support 12 and has a thickness of 0.5 μm or more and 20 μm or less. The hydrogen-permeable metal film 13 is formed of a palladium alloy (Pd-Ag in the present embodiment). The hydrogen-permeable metal film 13 is formed at the center of the porous support 12. Specifically, on the outer peripheral surface of the intermediate layer, a region up to 2 mm from both ends of the porous support 12 is an exposed region where the hydrogen-permeable metal film 13 is not formed and the outer peripheral surface of the intermediate layer is exposed. . Then, the remaining region is a region where the hydrogen-permeable metal film 13 is formed.

  As shown in FIGS. 1 to 3, each tube 11 is joined to holding members 21 and 22 via a sealing material 31. The sealing material 31 has a function of preventing gas from passing between the inner peripheral surface 14 and the outer peripheral surface 15 of the porous support 12 by being in close contact with the outer peripheral surface of the intermediate layer. The sealing material 31 of the present embodiment includes glass (for example, G018-311 manufactured by SCHOTT). The sealing material 31 fills the concave portions 25 of the holding members 21 and 22 and covers the end of the tube 11. More specifically, the sealing material 31 includes an exposed region (a region from both ends of the porous support 12 to 2 mm) and a part of a formation region (from both ends of the porous support 12) on the outer peripheral surface of the intermediate layer. (Area up to 3 mm). As a result, the length of the portion of the porous support 12 that functions as a gas permeable portion is 29 mm (= length of the porous support 12 35 mm− (length of the covering region of the sealing material 31 3 mm × 2)). Become. Further, the sealing material 31 is in close contact with the member back surface 24 of the upper holding members 21 and 22. Therefore, the holding members 21 and 22 adjacent in the vertical direction are joined to each other via the sealing material 31. Further, the sealing material 31 filled in the concave portion 25 of the uppermost holding members 21 and 22 is in close contact with the back surface of the plate member 28. Therefore, the uppermost holding members 21 and 22 and the plate member 28 are joined to each other via the sealing material 31.

As shown in FIG. 5, the hydrogen separator 1 of the present embodiment is used, for example, as a hydrogen separator for an exhaust pipe 41 of an automobile. In this case, when a hydrogen-containing gas (such as an exhaust gas of an automobile) is supplied from the upstream side of the exhaust pipe 41, the hydrogen-containing gas contacts the tube 11 of the hydrogen separation device 1. At this time, on the surface of the hydrogen-permeable metal film 13, hydrogen molecules contained in the hydrogen-containing gas are dissociated into hydrogen atoms and occluded in the palladium of the hydrogen-permeable metal film 13. The hydrogen atoms absorbed in the palladium diffuse in the palladium and bond with other hydrogen atoms on the back surface (the surface on the side of the porous support 12) of the hydrogen-permeable metal film 13, so that the hydrogen molecules are again generated. Becomes At this point, hydrogen is separated from the hydrogen-containing gas. Thereafter, the hydrogen passes through the porous support 12 and is guided into the tube 11 (the through hole 16). Then, the hydrogen is guided to the outside of the exhaust pipe 41 and is used as a hydrogen source at the time of starting the engine. Specifically, by reacting hydrogen with the exhaust gas when the engine is started, and reduces NOx in the exhaust gas, thereby purifying the harmless N _2.

  Next, a method for manufacturing the hydrogen separation device 1 will be described.

  First, the tube 11 is formed. Specifically, after mixing alumina powder, organic beads as a pore former, and an organic binder, an unfired ceramic molded body having a cylindrical shape with an outer diameter of 2 mm and a length of 35 mm is formed by extrusion. Next, a slurry is prepared by mixing alumina powder, an organic binder, a solvent, a plasticizer, and the like. Then, the unfired ceramic formed body is immersed in the slurry by a dip coating method to form a coating on the outer peripheral surface of the unfired ceramic formed body.

  Next, after performing a drying step, a degreasing step, and the like according to a known method, a firing step of heating the unfired ceramic molded body and the coating to a predetermined temperature at which alumina can be sintered (for example, about 1300 ° C. to 1500 ° C.) Do. As a result, the alumina of the unfired ceramic molded body and the alumina of the coating film are simultaneously sintered, and the porous support 12 having the intermediate layer formed on the outer peripheral surface 15 is obtained.

  Next, the surface of the porous support 12 is subjected to electroless palladium plating and electrolytic silver plating. Then, an alloy of Pd-Ag is formed by performing alloying heating at 750 ° C. in an inert atmosphere. As a result, a hydrogen-permeable metal film 13 made of Pd-Ag is formed on the surface of the intermediate layer. At this point, the tube 11 is completed.

  Further, the holding members 21 and 22 and the plate member 28 are formed. More specifically, first, alumina powder, organic beads, and an organic binder are mixed, and then cut to a predetermined size, so that a holding member ceramic molded body that becomes the holding members 21 and 22 and a plate member that becomes the plate member 28 And a ceramic molded body for molding. Further, press processing is performed using the upper die and the lower die to form the recess 25 and the holding recess 27 in the ceramic molding for the holding member. Next, the ceramic molded body for the holding member and the ceramic molded body for the plate member are degreased, and further fired at a predetermined temperature for a predetermined time. As a result, the alumina of the ceramic molding for the holding member and the alumina of the ceramic molding for the plate member are sintered, and the holding members 21 and 22 and the plate member 28 are formed. The recess 25 and the holding recess 27 may be formed in the holding members 21 and 22 by performing cutting after firing.

  Thereafter, the first end of the tube 11 is inserted into the holding recess 27 of the holding member 21, and the second end of the tube 11 is inserted into the holding recess 27 of the holding recess 22. As a result, the integrated body 10 in which both ends of the tube 11 are supported by the holding members 21 and 22 can be obtained. Next, a plurality of the obtained integrated bodies 10 (holding members 21 and 22) are vertically stacked, and the plate member 28 is stacked on the uppermost holding members 21 and 22. Further, the paste containing glass is poured into the concave portions 25 of the holding members 21 and 22 using a dispenser or the like, so that the concave portions 25 are filled with the paste. Further, the paste containing glass is heated to a predetermined temperature (for example, 700 ° C. to 1000 ° C.) in an air atmosphere. As a result, the paste is melted, and the sealing material 31 is formed. Note that instead of forming the sealing material 31 by pouring the paste, the sealing material 31 may be formed by printing a paste including the sealing material 31. Alternatively, the sealing material 31 may be formed by disposing a plate material including glass in the concave portion 25 and then melting the plate material. As a result, the plurality of tubes 11 are joined to the holding members 21 and 22 via the sealing material 31, and the holding members 21 and 22 vertically adjacent to each other are joined to each other via the sealing material 31, and the uppermost holding member 21 and 22 and the plate member 28 are joined to each other via the sealing material 31, and the hydrogen separation device 1 is completed.

  Therefore, according to the present embodiment, the following effects can be obtained.

  (1) In the hydrogen separation device 1 of the present embodiment, a space A1 through which gas passes is provided between the adjacent tubes 11. In addition, unlike the conventional structure in which a plurality of through holes are provided in a columnar porous support (so-called lotus root structure), the hydrogen separation device 1 includes a plurality of tubes (tubular porous support 12). Since the structures are independent from each other, it is possible to form the porous support 12 that is resistant to the passage of the gas to be relatively thin. As described above, the pressure loss when the gas passes through the inside of the hydrogen separation device 1 can be reduced. As a result, when the hydrogen-containing gas is passed between the inner peripheral surface 14 and the outer peripheral surface 15 of the porous support 12, the hydrogen contained in the hydrogen-containing gas loses hydrogen permeation formed on the porous support 12. Since the hydrogen-permeable metal film 13 permeates easily, the amount of permeated hydrogen per unit area of the hydrogen-permeable metal film 13 is not easily reduced. Therefore, it is possible to efficiently separate hydrogen using the hydrogen separation device 1.

  (2) In the present embodiment, the plurality of tubes 11 can be simultaneously and easily sealed simply by filling the recesses 25 of the holding members 21 and 22 with the sealing material 31. Therefore, leakage of gas from the tube 11 can be easily prevented.

  (3) By the way, when the hydrogen separation device has a conventional structure in which a plurality of through holes are provided in a columnar porous support (so-called lotus root structure), the through holes serving as flow paths are brought close to each other. For example, a honeycomb shape can be considered. However, when the honeycomb-shaped porous support becomes large and the partition walls become very thin, there is a problem that the honeycomb-shaped porous support is easily damaged because the thermal shock resistance against a rapid temperature rise is reduced. On the other hand, the hydrogen separation device 1 of the present embodiment includes a plurality of porous supports 12 that are independent for each flow path. In this case, since the thermal shock resistance of the porous support 12 increases, the porous support 12 is less likely to be damaged. Moreover, since the porous support 12 of the present embodiment is relatively thin and has a relatively small volume (that is, a small heat capacity), it has good follow-up properties with respect to the ambient temperature. That is, since the thermal shock resistance of the porous support 12 against a rapid temperature rise is high, the porous support 12 is harder to be damaged.

  (4) In the present embodiment, since the amount of hydrogen permeated per unit area of the hydrogen permeable metal membrane 13 is not easily reduced, the area of the hydrogen permeable metal membrane 13 can be reduced. 1 can be downsized. Therefore, the hydrogen separation device 1 can be installed in a narrow place such as the exhaust pipe 41 of the automobile (see FIG. 5).

  (5) The hydrogen-permeable metal film 13 of the present embodiment is a surface film formed on the outer peripheral surface 15 of the porous support 12. This makes it easier to increase the area of the hydrogen-permeable metal film 13 than when the hydrogen-permeable metal film 13 is formed on the inner peripheral surface 14 of the porous support 12, for example. More hydrogen can be obtained from the tube 11.

[Second embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. Here, a description will be given focusing on portions different from the first embodiment. In the present embodiment, the tube holding structure is different from that of the first embodiment.

  More specifically, as shown in FIGS. 6 and 7, the integrated body 60 constituting the hydrogen separation device 51 of the present embodiment includes ten tubes 61 (hydrogen separation bodies) and one holding member 71. Have. The tubes 61 are arranged on the holding member 71 in a straight line and at equal pitch. The holding member 71 holds only one end of each tube 61 in a state where the tubes 61 are separated from each other. More specifically, the holding member 71 holds the first end (the left end in FIG. 7) of each tube 61. The holding recess 77 provided in the holding member 71 holds the first end of the tube 61 when the first end of the tube 61 is inserted.

  At the second end (the right end in FIG. 7) of each tube 61, a cap 67 for closing the opening end of the through hole 66 on the second end side is provided. The hydrogen-permeable metal film 63 constituting the tube 61 is formed at the center and the second end of the porous support 62. Specifically, on the outer peripheral surface of the intermediate layer, the region from the first end (the left end in FIG. 7) of the porous support 62 to 3 mm is not formed with the hydrogen-permeable metal film 63, and the outer peripheral surface of the intermediate layer is not formed. This is an exposed area where the surface is exposed. Then, the remaining region is a region where the hydrogen-permeable metal film 63 is formed.

  As shown in FIG. 8, the hydrogen separation device 51 of this embodiment is used as a hydrogen separation device for an exhaust pipe 91 of an automobile, as in the first embodiment. In this case, when a hydrogen-containing gas (exhaust gas or the like) is supplied from the upstream side of the exhaust pipe 91, the hydrogen-containing gas contacts the tube 61 of the hydrogen separation device 51. Next, hydrogen is separated from the hydrogen-containing gas by the hydrogen-permeable metal film 63. Then, the hydrogen passes through the porous support 62 and is guided into the tube 61, and then is guided outside the exhaust pipe 91, and is used as a hydrogen source when the engine is started.

  Therefore, also in the present embodiment, a space A2 (see FIG. 7) through which the gas passes is provided between the adjacent tubes 61. In addition, since the hydrogen separation device 51 has a structure in which a plurality of tubes (tubular porous supports 62) are independent of each other, the porous support 62 which is a gas passage portion can be formed relatively thin. it can. As described above, the pressure loss when the gas passes through the inside of the hydrogen separation device 51 can be reduced. As a result, when the hydrogen-containing gas passes between the inner peripheral surface 14 and the outer peripheral surface 15 of the porous support 62, the hydrogen contained in the hydrogen-containing gas easily permeates the hydrogen-permeable metal film 63. Therefore, it is possible to efficiently separate hydrogen using the hydrogen separation device 51.

  The above embodiments may be modified as follows.

  In the hydrogen separator 1 of the first embodiment, hydrogen is separated from the hydrogen-containing gas supplied from the upstream side of the exhaust pipe 41, and the separated hydrogen is guided from the inside of the tube 11 to the outside of the exhaust pipe 41. Was. However, as shown in FIG. 9, hydrogen may be separated from the hydrogen-containing gas supplied in the tube 11 and the separated hydrogen may be introduced into the exhaust pipe 41 (outside the tube 11). The hydrogen introduced into the exhaust pipe 41 reacts with the exhaust gas flowing from the upstream side of the exhaust pipe 41 to purify NOx in the exhaust gas.

  Similarly, in the hydrogen separation device 51 of the second embodiment, hydrogen is separated from the hydrogen-containing gas supplied from the upstream side of the exhaust pipe 91, and the separated hydrogen is guided from the inside of the tube 61 to the outside of the exhaust pipe 91. Had become. However, as shown in FIG. 10, hydrogen may be separated from the hydrogen-containing gas supplied in the tube 61, and the separated hydrogen may be introduced into the exhaust pipe 91 (outside the tube 61). The hydrogen introduced into the exhaust pipe 91 reacts with the exhaust gas flowing from the upstream side of the exhaust pipe 91 to purify NOx in the exhaust gas.

  -The hydrogen separation device 1 of the first embodiment is configured by vertically stacking three holding members 21 and 22 (integrated body 10) in which a plurality of tubes 11 are arranged in a straight line. However, as shown in FIG. 11, the hydrogen separating apparatus 100 may be configured by laminating the holding members 101 and 102 (integrated body 103) in a plurality of stages (here, two stages) in the lateral direction. The holding members 101 and 102 adjacent to each other in the lateral direction are joined to each other via a sealing material 104. Further, the hydrogen separating apparatus may be configured by stacking a plurality of holding members (stacks) in the vertical direction (for example, three steps) and stacking a plurality of layers (for example, two steps) in the horizontal direction.

  In addition, as shown in FIG. 12, the hydrogen separating apparatus 110 may be configured by stacking a plurality of (here, two) stages of the holding members 111 and 112 (the integrated body 113) in the depth direction. Furthermore, the hydrogen separating apparatus may be configured by stacking a plurality of holding members (accumulated bodies) in the vertical direction (for example, three stages) and stacking a plurality of stages (for example, two stages) in the depth direction. Further, the hydrogen separating apparatus may be configured by stacking a plurality of holding members (accumulated bodies) in the horizontal direction (for example, two steps) and stacking a plurality of layers (for example, two steps) in the depth direction. As shown in FIG. 13, the holding members 121 and 122 (stack 123) are stacked in a plurality of stages (here, three stages) in the vertical direction, and a plurality of stages (here, two stages) are stacked in the depth direction. The hydrogen separation device 120 may be configured by laminating a plurality of stages (here, two stages) in the lateral direction.

  -The hydrogen separation device 51 of the second embodiment is formed by vertically stacking three holding members 71 (stacks 60) in each of which a plurality of tubes 61 are arranged in a straight line. However, as shown in FIG. 14, the hydrogen separating apparatus 130 may be configured by laminating a plurality of (here, two) stages of the holding member 131 (the integrated body 132) in the lateral direction. Furthermore, the hydrogen separating apparatus may be configured by stacking a plurality of (eg, three) holding members (stacks) in the vertical direction and stacking a plurality of (eg, two) stages in the horizontal direction.

  -As shown in the hydrogen separation device 140 of Figs. 15 and 16, in each of the holding members 141 and 142 (the integrated body 143), a return flow path for connecting two adjacent tubes 144 (hydrogen separated bodies). 145 (connection flow path) may be provided. In this case, in each of the holding members 141 and 142, the opening end of the through hole 146 of the tube 144 located at one end (the left end in FIG. 16) serves as a gas inlet, and the other end (the right end in FIG. 16). The open end of the through hole 146 of the tube 144 located serves as a gas outlet. In addition, as shown in FIG. 17, the return channel 145 may be accommodated inside the cover member 147 by attaching a box-shaped cover member 147 to the holding members 141 and 142.

  The hydrogen separators 1 and 51 of the above embodiments are the hydrogen separators installed in the exhaust pipes 41 and 91 of the automobile, but may be the hydrogen separators installed in other parts of the automobile. . In addition, the hydrogen separation apparatuses 1 and 51 of the above embodiments are separated from the hydrogen-containing gas by using a hydrogen-permeable metal membrane, and the separated hydrogen is supplied to a predetermined reaction system to cause a reduction reaction. May be used.

  Next, in addition to the technical ideas described in the claims, technical ideas grasped by the above-described embodiments will be listed below.

  (1) The hydrogen separator according to the above aspect 1, wherein the sealing material includes at least one of glass, glass ceramic, crystallized glass, and a composite material of glass and ceramic.

  (2) In the above-mentioned means 1, the hydrogen permeable metal membrane is a surface membrane formed on an outer peripheral surface of the porous support.

  (3) In the above-mentioned means 1, the hydrogen permeable metal membrane is formed at a central portion of the porous support.

  (4) The hydrogen separating apparatus according to the above (1), wherein the sealing member covers the holding member and an end of the porous support.

1, 51, 100, 110, 120, 130, 140 ... hydrogen separators 11, 61, 144 ... tubes 12 and 62 as hydrogen separators ... porous supports 13 and 63 ... hydrogen-permeable metal membranes 14 ... porous Inner peripheral surface 15 of support: outer peripheral surface 21, 22, 71, 101, 102, 111, 112, 121, 122, 131, 141, 142 of porous support: holding members 27, 77: holding recesses 31, 104 ... seal material 145 ... folded flow paths A1, A2 ... space as connection flow paths

Claims (5)

A plurality of hydrogen separators formed with a hydrogen-permeable metal membrane on a cylindrical porous support,
A holding member that holds at least one end of the plurality of hydrogen separators in a state where the plurality of hydrogen separators are separated from each other so as to have a space through which gas passes between the adjacent hydrogen separators. With
The holding member includes a plurality of holding recesses having a recess on an upper surface, and holding an end of the hydrogen separator on an inner bottom surface of the recess.
The plurality of hydrogen separators are joined to the holding member via a sealing material that prevents passage of the gas between the inner peripheral surface and the outer peripheral surface of the porous support,
A hydrogen separation device comprising a plurality of the holding members in which the plurality of hydrogen separators are arranged on a straight line. The hydrogen separator according to claim 1, wherein the porous support and the holding member are made of ceramic, and the sealing material is made of an inorganic material including glass.   3. The hydrogen separation device according to claim 1, wherein the adjacent holding members are joined to each other via the sealing material. 4.   The hydrogen separation device according to any one of claims 1 to 3, further comprising a connection flow path for connecting two or more hydrogen separation bodies.   The plurality of holding members in which the plurality of hydrogen separators are arranged in a straight line are stacked in at least one of a vertical direction, a horizontal direction, and a depth direction. The hydrogen separation device according to claim 1.

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