JP2007245123A - Composite multilayer structure hydrogen permeable membrane and method for producing the same - Google Patents

Abstract

An inexpensive hydrogen-permeable membrane that does not have pinholes even when rolled thin, has high permeation separation performance of high-purity hydrogen, and does not brittle hydrogen.
A hydrogen permeable membrane 1 having a composite multi-layer structure includes, from above, a catalytic metal layer 53 of Pd or Pd alloy, a fourth metal layer 51 having a low solid solubility limit with Pd, a metal hydride with a small hydrogen solid solution amount. A second metal layer 49 having a large hydrogen solid solution amount, a first metal layer 48 having a high hydrogen permeation performance, a third metal layer 50, a second metal layer 49, a third metal layer 50, The first metal layer 48, the third metal layer 50, the second metal layer 49, the fourth metal layer 51, and the catalyst metal layer 53 are stacked in this order. The composite core laminate 52 composed of the third metal layer 50 and the fourth metal layer 51 is formed by diffusion bonding and rolling, and the catalytic metal layer 53 is formed on both surfaces thereof. Increased.
[Selection] Figure 2

Description

  The present invention is a composite in which a hydrocarbon such as methane gas and steam are mixed and reformed at high temperature, and then only hydrogen gas is permeated and separated from the generated mixed gas to produce high purity hydrogen gas. The present invention relates to a hydrogen permeable membrane having a multilayer structure and a manufacturing method thereof.

  Conventionally, this type of hydrogen permeable membrane is known to be a single layer such as Pd that selectively transmits only hydrogen or an alloy containing 23% Ag in Pd. In some cases, a Pd alloy film is formed on the surface of the ceramic porous support by a plating method (see Patent Document 1).

  In addition, as a composite multilayer structure hydrogen permeable film having a sandwich structure, there is a film in which a Pd film or a Pd alloy film is disposed on both surfaces of a metal film having high hydrogen permeable performance (see Patent Document 2).

  First, the hydrogen separation method in which Pd or an alloy containing 23% Ag in Pd is used as a hydrogen permeable membrane will be briefly described.

  Usually, a hydrogen permeable membrane is used by rolling Pd or a Pd alloy into a thin film. For example, a cylindrical tube is made of a Pd film or a Pd alloy film, one end of the tube is sealed and welded, hydrogen gas in a pressurized state is supplied to the outside of the tube, and heated to a certain temperature. Molecules dissociate atomically, form a solid solution with Pd, and are taken into the Pd film.

  The incorporated hydrogen atoms diffuse from the outside of the high pressure tube to the low inside due to the difference in hydrogen partial pressure inside and outside the tube, and become hydrogen molecules again on the inside surface. Impurities other than hydrogen contained in the reformed gas produced from methane or methanol by steam reforming do not react with Pd, and therefore remain outside the tube, thereby purifying hydrogen.

  In a hydrogen permeable membrane containing only Pd, deterioration due to hydrogen embrittlement is a problem, and it is used after being alloyed. Already, Pd alloys with 23% Ag and 40% Cu are well known, and a hydrogen purification apparatus using a single tube made of only a Pd alloy film has been put into practical use. However, the thickness of the tube used is as thick as 80 μm or more in order to maintain the strength, and there is a problem that the amount of hydrogen permeation is small and expensive.

  FIG. 7 shows an example of a hydrogen permeable membrane in which a Pd alloy film is formed on the surface of a conventional ceramic porous support described in Patent Document 1 by plating. As shown in FIG. 7, the hydrogen separator 1 has a hydrogen separating ability such as Pd and Pd on a porous substrate 2 made of a cylindrical ceramic and a surface 2a of the porous substrate that is a surface to be treated outside thereof. And a hydrogen separation membrane 4 formed by electroless plating, and the diameter of the small holes 5 of the porous substrate 2 is not more than the thickness of the hydrogen separation membrane 4 and not less than 1 μm.

  Here, the operation of the cylindrical hydrogen separator 1 in which the hydrogen separation membrane 4 forms the outer surface will be described.

  First, pressurized raw material hydrogen gas is supplied to the outside of the cylindrical hydrogen separator 1, and when heated to a certain temperature, the hydrogen molecules in contact with the hydrogen separation membrane 4 on the surface of the porous substrate 2 become atomic. It dissociates, forms a solid solution with Pd, and is taken into the Pd membrane, that is, into the hydrogen separation membrane 4.

  The taken-in hydrogen atoms diffuse from the outer side of the hydrogen separation membrane 4 having a high pressure to the lower side due to the difference in hydrogen partial pressure inside and outside the hydrogen separation membrane 4, and become hydrogen molecules again on the inner surface thereof. After that, it flows in the small holes 5 of the cylindrical porous substrate 2 from the surface 2a of the porous body. Since many impurities contained in the reformed hydrogen gas do not react with Pd, they remain outside the hydrogen separator 1, thereby purifying the hydrogen.

  However, the conventional method of forming a Pd film or Pd alloy film on the outer surface of a porous substrate made of ceramic by plating can increase the mechanical strength of the structure, and is a thin film of about 1 to 5 μm with a certain amount. Even if the pore size of the porous support is selected so as not to affect the permeation amount, the plating thickness varies in the plating process and the Pd alloy film becomes thin. It is difficult to eliminate the leakage of the pinhole.

  Therefore, if there is an impurity in the reformed hydrogen gas generated as a result of the steam reforming, the purity of the hydrogen gas obtained through permeation through the film also deteriorates in proportion to the impurity concentration. For example, the thickness of the Pd alloy film At 5 μm, the purity was about 99.9%, and carbon monoxide of 50 ppm or more was mixed, so that the permeated gas could not be used by supplying it to a solid polymer membrane fuel cell. In addition, when used for a long time, the strength decreases due to hydrogen embrittlement, and in particular, there is a problem that deterioration of the pinhole portion is promoted and breakage easily occurs.

  FIG. 8 shows a hydrogen permeable membrane having a composite multilayer structure having a conventional sandwich structure described in Patent Document 2. As shown in FIG. 8, the hydrogen permeable film 6 is composed of a metal film 7 having a high hydrogen permeable performance and a Pd film or a Pd alloy film 8 disposed on both sides thereof.

  The hydrogen permeable membrane 6 having the sandwich structure is produced in the following forms (1) and (2).

  (1) The metal film 7 having high hydrogen permeation performance and the Pd film or the Pd alloy film 8 are dry-etched in vacuum to remove impurities and oxide layers on the surface. Etching can be performed by ion bombardment with inert gas ions. Thereafter, a Pd film or a Pd film is disposed on both surfaces of a metal film having a high hydrogen permeation performance while maintaining a vacuum, and is rolled in a vacuum.

  (2) The Pd film or the Pd alloy film 8 is disposed on both surfaces of the metal film 7 having high hydrogen permeation performance and heated in vacuum to remove impurities and oxide layers. A technique such as hot pressing can be applied to heating in vacuum. Then roll.

  An attachment method and operation of the hydrogen permeable membrane having the sandwich structure thus prepared will be described.

  As a mounting method, a hole is made in a stainless steel plate and a hydrogen permeable membrane is welded around the stainless steel plate so as to cover the hole, or in order to increase area efficiency, as shown in FIG. The hydrogen permeable membrane 6 is wound around the outer layer 10 of the body 9, and the joining portion 11 is welded with nickel brazing or copper brazing 12 to make a cylindrical tube.

  Next, one end of the tube is hermetically welded, and pressurized raw material hydrogen gas is supplied to the outside of the tube. When heated to a certain temperature, the hydrogen molecules in contact with the tube surface dissociate into atoms, form a solid solution with Pd, and are taken into the Pd film. Due to the difference in hydrogen partial pressure between the inside and outside of the tube, the incorporated hydrogen atoms quickly diffuse from the outside of the tube with high hydrogen partial pressure through the metal film with high hydrogen permeability to the inside with low hydrogen partial pressure. It becomes hydrogen molecule again. Many impurities contained in the reformed hydrogen gas do not react with Pd and remain outside the tube, thereby purifying the hydrogen.

  In the hydrogen permeable membrane 6 having the sandwich structure formed in this way, the metal 7 having a high hydrogen diffusion coefficient and high hydrogen permeation performance is used for the core material. Therefore, the hydrogen permeable membrane 6 having a sandwich structure has a higher hydrogen content than that using a single Pd alloy tube. A product with high transmission performance is obtained. In addition, since a Pd film or alloy film is arranged on both sides of a metal film having high hydrogen permeation performance, an oxide film layer is not formed on the surface, and since it has a laminated structure, it is a dense composite multilayer having no pinholes. A hydrogen permeable membrane having a composite multilayer structure is obtained.

  However, even if the Pd film or the Pd alloy film is uniformly arranged, it is difficult to prevent hydrogen embrittlement of a metal film having high hydrogen permeability, which is considered to be particularly weak in hydrogen embrittlement, and the hydrogen permeation operation is repeated several times. And physical properties deteriorate due to hydrogen embrittlement.

  In addition, in a hydrogen permeable membrane in which a Pd (palladium) coating layer is formed on both sides of a V (vanadium) base layer as in Patent Document 2, interdiffusion between V and Pd proceeds under practical temperature conditions, and V is the surface. The catalyst layer moves to Pd, and further precipitates on the outer surface of Pd, and easily oxidizes V to form an oxide film, which loses the catalytic ability to atomize and dissociate hydrogen molecules, resulting in hydrogen permeation performance. There was a problem of being lowered.

  As a method for solving the above problems, Patent Document 3 discloses a composite phase of a phase responsible for hydrogen permeation performance and a phase responsible for hydrogen embrittlement resistance, and NbTi phase (hydrogen permeable phase) in which Ni is dissolved, and Nb. A hydrogen permeable membrane of a multiphase alloy with a solid solution NbTi phase (hydrogen embrittlement resistant phase) is disclosed.

Patent Document 4 discloses a hydrogen permeable film in which a SiO ₂ intermediate layer is interposed between a V base layer and a Pd coating layer. Further, Patent Document 5 discloses a metal base layer containing a VA group element, A metal intermediate layer formed on at least one of the two surfaces of the metal base layer and containing an element selected from Ni (nickel) and Co (cobalt), and of the two surfaces of the metal intermediate layer A hydrogen permeable membrane is disclosed that is formed on a surface on which a metal base layer is not formed and includes a metal coating layer containing Pd (palladium).
JP 2000-317282 A JP-A-11-276866 JP 2005-232491 A JP-A-7-185277 JP 2003-112020 A

  However, as shown in Patent Document 3 above, it is a composite phase of a phase responsible for hydrogen permeation performance and a phase responsible for hydrogen embrittlement resistance, and an NbTi phase (hydrogen permeable phase) in which Nb is dissolved and Ni is solidified. In a hydrogen permeable membrane of a dual phase alloy with a melted NiTi phase (hydrogen embrittlement resistant phase), the ductility of the alloy is poor, and it is extremely difficult to roll thinly after forming the alloy by arc melting. There is a problem that the thickness of 2 mm or more is the limit, the material cannot be rolled up thinly to increase the hydrogen permeation amount, and the material price becomes high.

Further, in the hydrogen permeable membrane in which the SiO ₂ intermediate layer is interposed between the V base layer and the Pd coating layer as shown in Patent Document 4, diffusion between V and Pd can be reduced. The ceramic intermediate layer such as SiO ₂ has a problem that the hydrogen permeation performance is very poor.

  This is because the ceramic intermediate layer only allows hydrogen in the molecular state to pass through. Since hydrogen needs to be recombined once before passing through the ceramic intermediate layer and then dissociated again after passing through, the hydrogen is required. Transmission performance is low. Furthermore, when ceramic and metal are joined, there are problems that the production is relatively difficult and the hydrogen permeable membrane is easily cracked due to the difference in thermal expansion coefficient.

  Patent Document 5 is formed on at least one of two surfaces of a metal base layer containing a VA group element and the metal base layer, and is selected from Ni (nickel) and Co (cobalt). A metal intermediate layer containing an element and a metal coating layer containing Pd (palladium), which is formed on a surface of the two metal intermediate layers on which the metal base layer is not formed, selectively transmits hydrogen. Although it is a hydrogen permeable membrane, it has better adhesion and better hydrogen permeation performance than the previous ceramic intermediate layer, and the interdiffusion is reduced and deterioration of hydrogen permeation performance can be suppressed.

  However, when a nickel or cobalt intermediate layer having a low hydrogen solubility even though the diffusion coefficient is large is formed on the permeable membrane, there is a problem that the hydrogen permeation performance in that portion is extremely lowered. In addition, the metal serving as the metal base layer containing the VA group element has a problem in that physical properties deteriorate due to hydrogen embrittlement because hydride is formed through the presence of hydrogen and volume expansion is repeated.

  The present invention solves the above-described conventional problems, and there is no pinhole that permeates and separates only hydrogen gas from a mixed gas after methane gas or the like is subjected to steam reforming treatment to produce high-purity hydrogen gas, An object of the present invention is to provide an inexpensive composite multilayer structure hydrogen permeable membrane having good hydrogen permeation separation performance and not hydrogen embrittlement, and a method for producing the same.

  In order to achieve the above object, the composite multilayer structure hydrogen permeable membrane of the present invention is Ta, Nb, V, which is a high melting point transition metal having a body-centered cubic structure as a first metal layer having high hydrogen permeability. One of Ta alloy, Nb alloy, and V alloy is used, and either Ni or Co is used from the group VIII transition metal elements as the second metal layer having a small amount of hydrogen solid solution and difficult to form a metal hydride. As the third metal layer having a large hydrogen solid solution amount, one of Ti, Zr, and Hf is used from the transition metal elements of group IVA, and each metal layer constitutes a laminate, and both sides of the laminate are formed. It is a hydrogen permeable membrane having a composite multilayer structure formed by forming a catalytic metal layer of Pd or Pd alloy.

  In addition, it is a hydrogen permeable membrane having a composite multilayer structure using Cr, Mo, and W, which are transition metals belonging to Group VIA, as a fourth metal layer having a low solid solubility limit with Pd in the uppermost layer of the laminate.

  In addition, a first metal plate made of a base metal with high hydrogen permeation performance, a second metal plate having a small hydrogen solid solution amount and difficult to form a metal hydride, a third metal plate having a large hydrogen solid solution amount, and further required Correspondingly, a stacking step of stacking Pd and a fourth metal layer having a low solid solubility limit on the uppermost layer to form a stacked product, and a catalyst metal plate made of Pd or a Pd alloy are stacked on the upper and lower surfaces of the stacked product. Laminated product forming step with a catalyst metal, a diffusion bonding step in which the laminate with a catalyst metal is diffusion bonded by heat and pressure to form a diffusion bonded product, and the diffusion bonded product is rolled to a predetermined thickness and rolled composite core laminate And a rolling step. The present invention also provides a method for producing a hydrogen permeable membrane having a composite multilayer structure in which a rolled composite core laminate rolled to a predetermined thickness is subjected to additional heat treatment for alloying the second metal layer and the third metal layer.

  As a result, the alloyed layer having high hydrogen embrittlement resistance, which forms the first metal layer of the base metal having high hydrogen permeation performance with the second metal layer and the third metal layer, acts as a reinforcing layer, and the hydrogen of the first metal layer A fourth metal layer that suppresses brittleness and hardly diffuses with Pd between the Pd catalyst metal layer is formed, and mutual diffusion to the catalyst metal layer of the base metal is suppressed.

  Also, expensive Pd is only used on both surfaces of the composite multilayer structure hydrogen permeable membrane, resulting in a thin and inexpensive hydrogen permeable membrane free of pinholes.

  A hydrogen permeable membrane having a composite multilayer structure according to the present invention and a method for manufacturing the hydrogen permeable membrane comprising a first metal layer of a base metal having a high hydrogen permeation performance formed of a second metal layer and a third metal layer are formed into a highly hydrogen-brittle alloy. Since the layer serves as a protective layer, hydrogen embrittlement of the first metal layer is suppressed. Further, by forming a fourth metal layer that is difficult to diffuse with Pd between the Pd catalyst metal layer, mutual diffusion to the catalyst metal layer of the base metal is suppressed, and a plurality of laminates As a result, since the structure is divided in an extremely thin film state, distortion due to volume expansion is reduced, and deterioration of physical properties due to hydrogen embrittlement is further suppressed.

  Also, expensive Pd is only used on both surfaces of the composite multilayer structure hydrogen permeable membrane, resulting in a thin and inexpensive hydrogen permeable membrane free of pinholes.

  In addition, by adopting thin film production methods by diffusion bonding and rolling, hydrogen permeable membranes have fewer pinholes, and additional heat treatment is performed after rolling, making it possible to thinly roll, but with a perfect alloying layer, it is resistant to hydrogen embrittlement. The effect will be demonstrated more.

  The invention of the hydrogen permeable membrane having a composite multilayer structure according to claim 1 includes a first metal layer having a high hydrogen permeation performance, a second metal layer having a small hydrogen solid solution amount and difficult to form a metal hydride, and a hydrogen solid solution amount. And a catalyst metal layer of Pd or Pd alloy is formed on both sides of the laminate, and the first metal layer is the second metal layer and the third metal layer. It is protected by an alloy layer with a metal layer, hydrogen embrittlement is suppressed, and even if it is thinly rolled, there are no pinholes due to its multilayer structure, high-permeability hydrogen permeation separation performance is good, and high-performance hydrogen permeation can be maintained.

  The invention of the hydrogen permeable membrane having a composite multilayer structure according to claim 2 has a fourth metal layer having a lower solid solubility limit with Pd in the uppermost layer of the laminate according to claim 1. By forming a second metal layer that is hard to diffuse with the Pd catalyst metal layer as the uppermost lower layer, mutual diffusion between the first metal layer and the catalyst metal layer is suppressed, and the catalytic function of the surface layer is stabilized. The base metal layer is prevented from being deposited on the surface of the catalyst metal layer, and long-term reliability can be ensured.

  The invention of the hydrogen permeable membrane having a composite multilayer structure according to claim 3 is formed by laminating the second metal layer and the third metal layer in the invention according to claim 1 or 2 so as to be in direct contact with each other. The second metal layer, which has a small amount of hydrogen solid solution and is difficult to form a metal hydride, and the third metal layer, which has a large amount of hydrogen solid solution, are opposed to each other. Then, it becomes an alloyed layer having a hydrogen embrittlement effect, and the hydrogen embrittlement resistance of the first metal layer is increased without deteriorating the hydrogen permeation performance.

  The invention of the hydrogen permeable membrane having a composite multilayer structure according to claim 4 is the third metal layer between the first metal layer and the second metal layer in the invention according to any one of claims 1 to 3. Since the first metal layer and the second metal layer are easy to form a hard intermetallic compound, if the first metal layer and the second metal layer are opposed to each other, the film is thinned in the rolling process. In addition, the third metal layer is a metal that is relatively easy to be diffusion bonded, and enables diffusion bonding at a low temperature.

  The invention of the hydrogen permeable membrane having a composite multilayer structure according to claim 5 is the second metal layer between the third metal layer and the fourth metal layer according to any one of claims 2 to 4. The third metal layer is relatively easy to diffuse, and directly facing the fourth metal layer, the third metal layer is deposited on the Pd surface which is the catalytic metal layer through the fourth metal layer, The catalytic ability will be reduced. Therefore, by interposing the second metal layer, diffusion of the third metal layer to the catalytic metal surface is prevented.

  The invention of the hydrogen permeable membrane having a composite multilayer structure according to claim 6 is the laminate according to any one of claims 1 to 5, wherein the first metal layer is a second metal layer and a third metal layer. And sandwiching the first metal layer with the alloy forming layer of the second metal layer and the third metal layer to form the first metal In addition to reliably suppressing the hydrogen embrittlement of the layer, the sandwich body has two or more layers to prevent the propagation of hydrogen embrittlement.

  The invention of the hydrogen permeable membrane having a composite multilayer structure according to claim 7 is the invention according to any one of claims 1 to 6, wherein the metal element of the third metal layer is compared with the number of metal elements of the second metal layer. The ratio is an element ratio of 0.8 to 1.2, and the metal element ratio of the third metal layer is about 1: 1 with respect to the number of metal elements of the second metal layer. Strengthens hydrogen embrittlement resistance and maintains appropriate hydrogen permeation performance.

  In the invention of the hydrogen permeable membrane having the composite multilayer structure according to claim 8, the ratio of the second metal layer to the first metal layer in the invention according to any one of claims 1 to 7 is converted into an element ratio. When the ratio of the second metal layer to the first metal layer is 1% or less in terms of element ratio, the effect of hydrogen embrittlement resistance is poor, and 30% or more. Then, the hydrogen permeation performance is extremely lowered.

  In the invention of the hydrogen permeable membrane having the composite multilayer structure according to claim 9, the ratio of the fourth metal layer to the first metal layer in the invention according to any one of claims 2 to 8 is converted into an element ratio. The ratio of the fourth metal layer to the first metal layer is 0.1% or less in terms of the element ratio, and the interdiffusion is suppressed. The effect is small, and if it is 10% or more, the hydrogen permeation performance is remarkably lowered.

  The invention of the hydrogen permeable membrane having a composite multilayer structure according to claim 10 is characterized in that the first metal layer having high hydrogen permeability in the invention according to any one of claims 1 to 9 has a body-centered cubic structure. A VA group metal of transition metal having a melting point or an alloy thereof, and a VA group metal having a body-centered cubic structure is a metal having a high hydrogen diffusion coefficient and a relatively high hydrogen permeation performance. The performance as a membrane can be ensured, the area of the hydrogen permeable membrane required for the hydrogen generator can be reduced, and the size of the device itself can be made compact.

  In the invention of the hydrogen permeable membrane having a composite multilayer structure according to claim 11, the first metal layer having a high hydrogen permeability in the invention according to any one of claims 1 to 10, wherein the first metal layer having a body-centered cubic structure is high. It is one of Ta, Nb, V, Ta alloy, Nb alloy, and V alloy, which are transition metals of melting point. Ta, Nb, and V not only have a high hydrogen diffusion coefficient but also a large hydrogen solid solubility. It is a metal that is particularly excellent in hydrogen permeation performance, can improve the performance as a hydrogen permeable membrane with a composite multilayer structure, and can be applied in a smaller area when applied to a hydrogen generator, and the size of the device itself Can be made more compact.

  The invention of the hydrogen permeable membrane of the composite multilayer structure according to claim 12 is a second metal layer having a small hydrogen solid solution amount and difficult to form a metal hydride in the invention according to any one of claims 1 to 11, Among the transition metal elements of Group VIII, either Ni or Co is used, and Ni or Co is not only difficult to form hydrogen and metal hydrides, but is a versatile metal and relatively inexpensive, Further, even if it itself has a catalytic effect and diffuses into Pd, the catalytic effect of Pd is not greatly reduced.

  The invention of the hydrogen permeable membrane having a composite multilayer structure according to claim 13 is a transition metal element of group IVA as the third metal layer having a large hydrogen solid solution amount in the invention according to any one of claims 1 to 12. Among these, Ti, Zr, and Hf are used, and Ti, Zr, and Hf are not only large in hydrogen employment amount but also relatively versatile and inexpensive.

  The invention of the hydrogen permeable membrane having a composite multilayer structure according to claim 14 is characterized in that the fourth metal layer having a low solid solubility limit with Pd in the invention according to any one of claims 1 to 13 is a transition of the VIA group. One of the metals Cr, Mo, and W is used, and Cr, Mo, and W have a low solid solubility limit with Pd, so that they do not easily diffuse into Pd and form metal hydrides. The VA group metal is a difficult metal, and is a metal which is solid-dissolved in its entirety. When dissolved, the VA group metal suppresses the hydrogen embrittlement of the VA group metal and remarkably exhibits a function of suppressing mutual diffusion.

  The invention of the method for producing a hydrogen permeable membrane having a composite multilayer structure according to claim 15 includes a first metal plate made of a base metal having a high hydrogen permeation performance and a second metal plate having a small amount of hydrogen solid solution and difficult to form a metal hydride. And a third metal plate having a large amount of hydrogen solid solution are laminated to form a laminated product, a diffusion bonding step in which the laminated product is diffusion bonded by heat and pressure to form a diffusion bonded product, and the diffusion bonded product is predetermined A rolling step to form a rolled composite core laminate, and a catalyst metal layer forming step of forming a catalyst metal layer made of Pd or Pd alloy on both sides of the composite core laminate, By laminating one metal layer, second metal layer, and third metal layer by diffusion bonding, and further rolling, there are no pinholes, hydrogen embrittlement resistance, and hydrogen permeation taking advantage of the features of each metal layer. A high-performance hydrogen permeable membrane It is intended to.

  The invention of the method for producing a hydrogen permeable membrane having a composite multilayer structure according to claim 16 comprises the step of forming a catalyst metal layer comprising Pd or a Pd alloy in the invention according to claim 15 by vacuum deposition, Since either the sputtering method or the ion plating method is used and the Pd film is formed after forming the thin film that becomes the core of the hydrogen permeable film, it is not affected by the heat during diffusion bonding. The catalyst performance of Pd is not deteriorated and can be processed relatively easily.

  The invention of the method for producing a hydrogen permeable membrane having a composite multilayer structure according to claim 17 includes a first metal plate made of a base metal having high hydrogen permeation performance and a second metal plate having a small amount of hydrogen solid solution and difficult to form a metal hydride. And a third metal plate having a large hydrogen solid solution amount and, if necessary, a Pd and a fourth metal plate having a low solid solubility limit on the lowermost layer to form a laminate, A laminated product forming step with a catalyst metal, in which a catalytic metal plate made of Pd or Pd alloy is laminated on the lower surface, a diffusion bonding step in which the laminated product with catalyst metal is diffusion bonded by heat and pressure to form a diffusion bonded product, and the diffusion Rolling the joined product to a predetermined thickness to form a rolled composite core laminate, and by laminating the Pd catalyst metal layer simultaneously with other metal layers in the diffusion joining step, Simplify the process and form an inexpensive hydrogen permeable membrane That.

  The invention of the method for producing a hydrogen permeable membrane having a composite multilayer structure according to claim 18 is the invention according to any one of claims 15 to 17, wherein the diffusion bonded product is rolled to a predetermined thickness and rolled composite core lamination After the rolling step to form a body, an additional heat treatment for alloying the second metal layer and the third metal layer is performed. Alloying with the third metal layer proceeds more than necessary, and the elongation is poor during rolling in the subsequent process, making it difficult to process. Therefore, by performing heat treatment for alloying in a subsequent process, the minimum necessary heat is applied at the time of diffusion bonding to facilitate the thinning process by rolling.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments.
(Embodiment 1)
FIG. 1 is a schematic configuration diagram of a hydrogen generation / separation apparatus 22 incorporating a hydrogen permeable membrane 21 having a composite multilayer structure according to the first embodiment. FIG. 2 is an enlarged cross-sectional view of the hydrogen permeable membrane 21 having a composite multilayer structure according to the embodiment. FIG. 3 is a schematic cross-sectional configuration diagram of a diffusion bonding apparatus 23 that diffusion bonds a metal plate used for manufacturing the hydrogen permeable membrane 21 having the composite multilayer structure according to Embodiment 1 of the present invention. FIG. 4 is an enlarged sectional view showing a press member 73 of the diffusion bonding apparatus 23 in the same embodiment. FIG. 5 is a cross-sectional view of the rolling mill 20 used for manufacturing the hydrogen permeable membrane 21 having the composite multilayer structure according to the first embodiment of the present invention. FIG. 6 is a process diagram showing a manufacturing process of the hydrogen permeable membrane 21 having the composite multilayer structure according to the first embodiment of the present invention.

  In FIG. 1, the hydrogen generation / separation apparatus 22 includes a reaction chamber 25 that generates a hydrogen mixed gas by reacting a hydrocarbon gas and water vapor at a high temperature of 300 ° C. or more and 1550 ° C. or less, and a mixture generated in the reaction chamber 25. It consists of a hydrogen permeable membrane 21 having a composite multilayer structure that transmits only hydrogen gas in the gas, and a separation chamber 26 that passes through the hydrogen permeable membrane 21 having a composite multilayer structure and is separated as a high-purity hydrogen gas. The reaction chamber 25 and the separation chamber 26 are configured to be divided into two independent chambers by a hydrogen permeable membrane 21 having a composite multilayer structure.

  The reaction chamber 25 is a rectangular reaction vessel 28 made of a stainless steel plate having a connection opening 27 at the top, and a flange 29 is formed on the entire periphery of the connection opening 27 so as to project outward.

  Further, the wall surface 30 of the reaction chamber 25 has a supply port 31 that communicates with the outside of the hydrogen generator / separator 22 and supplies fuel, and an exhaust port 32 that discharges the residual gas after the reforming process. The supply port 31 and the discharge port 32 are arranged as far as possible from each other, and a reforming catalyst 33 made of continuous nickel foam is inserted in the space between the supply port 31 and the discharge port 32 of the reaction chamber 25. A heating means 34 for heating the reaction chamber 25 is disposed below the reaction chamber 25.

  The separation chamber 26 includes a stainless steel separation container 36 having a connection opening 35 below, and a flange 37 projecting outward is formed around the connection opening 35 so as to correspond to the flange 29 of the reaction chamber 25. It is formed.

  The side surface of the outer shell 38 of the separation chamber 26 has an inlet 39 for introducing a sweep gas such as water vapor that communicates with the outside of the hydrogen generator / separator 22 and a discharge port 40 for discharging the generated hydrogen. Yes.

  The hydrogen permeable membrane 21 having a composite multilayer structure is located at the joint of the flange 37 of the separation chamber 26 and the flange 29 of the reaction chamber 25, and through a gasket 41 and a gasket 42 installed on the flange 29 and the flange 37, A plurality of bolts 43 and nuts 44 outside the flange 29 and the flange 37 are fastened and fixed.

  Further, in order to minimize the deformation of the hydrogen permeable membrane 21 having a composite multilayer structure that is attached so as to cover the connection opening 27 and the connection opening 35, the hydrogen permeable membrane 21, the flange 29, and the flange having the composite multilayer structure. A spacer 46 made of a stainless porous material is interposed so as to be supported by the protrusions 45 of 37.

  Further, the pressure in the reaction chamber 25 can be adjusted by installing a pressure adjusting valve 47 downstream of the discharge port 32 so that the pressure in the reaction chamber 25 is higher than that in the separation chamber 26.

  Note that the gasket 41 and the gasket 42 may be made of mild steel or copper metal, but considering the influence of damage to the hydrogen permeable membrane 21 having a composite multilayer structure, it is preferable to use more flexible graphite. As the gasket material used this time, highly purified graphite (Nippon Carbon Co., Ltd., Nika Film, FL-300SH) was used.

  As the porous stainless steel material used for the spacer 46, a mesh-like filter material made of SUS316 material was used.

  In FIG. 2, a hydrogen permeable membrane 21 having a composite multilayer structure includes a first metal layer 48 made of Ta (tantalum) as a base metal having high hydrogen permeable performance, and a second metal made of Ni (nickel) that hardly forms metal hydrides. The layer 49 and the third metal layer 50 made of Ti (titanium) having a large hydrogen solid solution are laminated, and the composite core laminated body 52 becomes the fourth metal layer 51 whose uppermost lower layer is Mo (molybdenum). The composite core laminate 52 has a composite multilayer structure in which a catalytic metal layer 53 made of Pd or Pd alloy is formed on both upper and lower surfaces.

  Here, Ni of the second metal layer 49 and Ti of the third metal layer 50 are laminated so as to be in direct contact with each other, and between the Ta of the first metal layer 48 and the Ni of the second metal layer 49. Further, there is a laminated body 52 in which Ti of the third metal layer 50 is interposed and Ni of the second metal layer 49 is formed between Ti of the third metal layer 50 and Mo of the fourth metal layer 51.

  A composite core laminate 52 having two sandwich bodies 54 in which Ta of the first metal layer 48 is sandwiched between alloy formation layers of Ni of the second metal layer 49 and Ti of the third metal layer 50. Was used for the hydrogen permeable membrane 21 having a composite multilayer structure.

  The hydrogen permeable membrane 21 of this composite multilayer structure has a total thickness of 50 μm, the Ti metal element ratio of the third metal layer 50 is the same as the Ni metal element number of the second metal layer 49, and Ni and Ti are Allocation was made so that the alloy was almost one-to-one.

  Ni in the second metal layer 49 corresponds to 10% in terms of the element ratio in terms of the first metal layer 48, and the ratio of the fourth metal layer 51 to the first metal layer 48 in terms of element ratio. The distribution is equivalent to 1%.

  Therefore, the original plate thickness and the number of each metal layer of the hydrogen permeable membrane 21 shown in the first embodiment are as follows: Ta of the first metal layer 48 is two 500 μm thick, and Ni of the second metal layer 49 is 10 μm thick. 3 layers, 4 Ti layers of the third metal layer 50 and 4 pieces of 10 μm thickness, and Mo layers of the fourth metal layer 51 were sequentially laminated as the composite core laminate 52. Further, Pd of a 50 μm metal catalyst layer 53 is laminated on the upper and lower surfaces.

  Next, a method for manufacturing the hydrogen permeable membrane 21 having the composite multilayer structure according to the first embodiment of the present invention will be described with reference to FIGS.

  In FIG. 3, the diffusion bonding apparatus 23 includes a vacuum chamber 61, a high temperature diffusion furnace 62, and a hydraulic press 63.

  The vacuum chamber 61 includes a stainless upper chamber 64 and a lower chamber 65, and a vacuum pump 66 using an oil rotary pump and an oil diffusion pump as a vacuum exhaust system. The chamber 64 and the lower chamber 65 can be opened and closed up and down.

  The high-temperature diffusion furnace 62 is surrounded by a ceramic heat insulating wall 69 having a structure (not shown) that can be opened on the front surface, and a heater 70 made of Kanthal having high heat resistance is embedded therein. 71 can control the temperature in the high-temperature diffusion furnace 62.

  There is a lower stage 72 in the high-temperature diffusion furnace 62, and by installing a press member 73 on the lower stage 72, the upper stage 74 can be lowered by the hydraulic press 63 and pressure can be applied to the press member 73.

  The drive shaft 75 of the upper stage 74 passes through the heat insulating wall 69 and the upper chamber 64 and is connected to the hydraulic press 63. The intersection 76 between the drive shaft 75 and the upper chamber 64 is a drivable airtight mechanism using a bellows or the like. Thus, the inside of the vacuum chamber 61 and the outside are completely sealed.

  In FIG. 4, a press member 73 is composed of two support bolts 78a and 78b for fixing an upper pressurizing flat plate jig 77a and a lower pressurizing flat plate jig 77b fixed to each other by cutting a SUS316L stainless steel plate into a certain size. It is configured.

  Between the upper and lower pressurizing flat plate jigs 77a and 77b, a first metal plate 79, a second metal plate 80, a third metal plate 81, a fourth metal plate 82, and a metal catalyst plate 83 are arranged from above with a metal. Catalyst plate 83, fourth metal plate 82, second metal plate 80, third metal plate 81, first metal plate 79, third metal plate 81, second metal plate 80, third metal plate 81, first metal plate 79, a third metal plate 81, a second metal plate 80, a fourth metal plate 82, and a metal catalyst plate 83 are stacked in the order of stacked products 84.

  Further, there is no generation of gas due to heat between both surfaces of the laminate 84 and the pressurizing flat jigs 77a and 77b, and the elastic deformation is caused by pressurization, and the surface of the laminate 84 and the pressurizing flat jigs 77a and 77b. The release sheet 85a, 85b having good releasability after the diffusion bonding process is interposed.

  Examples of the material of the peelable sheets 85a and 85b include silica fiber nonwoven fabric (Advantech Toyo Co., Ltd., silica fiber filter paper, QR-100) that has been highly purified at 1000 ° C. or higher, and graphite that has been highly purified at about 2000 ° C. (Nippon Carbon Co., Ltd., Nika Film, FL-300SH) and carbon fiber felt (Nihon Carbon Co., Carboron, GF-20-2F) that has been highly purified at about 2000 ° C. can be used.

  In FIG. 5, the rolling mill 20 includes an upper roll 88 and a lower roll 89 that are rotated at a predetermined speed by a power source of a motor 87 of a mechanical unit 86, and an adjustment handle 90 that adjusts the interval between the upper and lower rolls 88 and 89. Therefore, the workpiece 91 is repeatedly rolled to reduce the thickness to a predetermined thickness while the interval between the upper and lower rolls 88 and 89 is gradually set smaller than the thickness of the workpiece 91 with the adjusting handle 90.

  Next, the manufacturing method until the laminated article 84 of the present embodiment is bonded by diffusion bonding to form the hydrogen permeable membrane 21 and the operation during the diffusion bonding process will be described with reference to the process diagram of FIG.

  In order to manufacture the hydrogen permeable membrane 21 having the composite multilayer structure of the present embodiment, first, a first metal plate 79 of Ta having a thickness of 500 μm, which is a base metal having high hydrogen permeability, and a metal having a low hydrogen solid solubility. A 10 μm thick Ni second metal plate 80 that is difficult to form hydride, a 10 μm Ti plate that is a third metal plate 81 having a high hydrogen solubility, a 10 μm Mo plate that is a fourth metal plate 82, and a metal catalyst A 50 μm Pd plate serving as a plate is prepared, and cleaning, degreasing, etching, and the like are performed in a pretreatment process.

  Next, the second metal plate 80 and the third metal plate 81 are laminated to form a pre-laminated body, and set from both sides of the first metal plate 79 so as to be in contact with the surface of the third metal plate 81 of the pre-laminated body. Construct a sandwich plate. Next, the sandwich plate is bonded with the 10 μm Ti plate of the third metal plate 81 interposed therebetween to form a multilayer sandwich plate. Further, a laminated body is formed by interposing a 10 μm Mo plate of the fourth metal plate 82 from the upper surface and the lower surface of the multilayer sandwich plate, and a 50 μm Pd plate serving as the metal catalyst layer 53 is laminated from above and below to obtain a laminated product 84. Then, a felt of carbon fiber subjected to high-purity treatment as a peelable sheet 85b is placed on a flat plate jig 77b for lower pressure, and a laminate 84 is set thereon.

  Further, the same peelable sheet 85 a and the upper pressurizing flat plate jig 77 a are sequentially placed thereon, and lightly tightened with the support bolts 78 a and 78 b to prepare as the press member 73.

  Next, in the diffusion bonding step, the vacuum chamber 61 of the diffusion bonding apparatus 23 is removed from the pin 68 of the connecting portion 67, the upper chamber 64 is moved upward, and the vacuum chamber 61 is opened. Next, the heat insulating wall 69 of the high temperature diffusion furnace 62 is opened, the prepared press member 73 is set on the lower stage 72 of the hydraulic press 63 in the middle, the heat insulating wall 69 is closed, and the vacuum chamber 61 is fixed. The vacuum chamber 61 is sealed by returning the position and fixing the connecting portion 67 with the pin 68.

Next, the vacuum pump 66 is operated, the degree of vacuum in the vacuum chamber 61 is lowered to 10 ⁻⁵ Pa or less, the heater power is turned on, and the controller 71 raises the temperature to 900 ° C. After confirming the rise, the hydraulic press 63 is driven, the upper stage 74 is lowered, and the press member 73 is pressurized so that a pressure of about 0.1 MPa is applied, and left at 900 ° C. for 2 hours.

  Thereafter, the heater power supply is turned off and the furnace is cooled to 50 ° C., whereby the diffusion bonding process is completed and a primary diffusion bonded product is obtained.

  When the press member 73 is pressurized, the peelable sheets 85a and 85b made of highly purified carbon fiber felt that is elastically deformed by the pressure are deformed, but the first metal plate 79 and the second metal plate 79 are deformed. The two metal plate 80, the third metal plate 81, the fourth metal plate 82, and the catalyst metal plate 83 are uniformly adhered, and the diffusion interface is smoothly performed by the adhesion interface of the surfaces of the respective metal plates being adhered all over. It becomes.

  Next, after cooling to 50 ° C., a rolling process is performed in which a 1190 μm diffusion bonded product prepared by diffusion bonding with the two-stage rolling mill 20 is roll-rolled to 50 μm.

  As a rolling process, it sets so that it may become a compression ratio of 2 to 3% from the thickness of the diffusion joining goods which are to-be-rolled goods, and it rolls by repeatedly passing the clearance gap between the upper and lower rolls 88 and 89. At this time, if the rolling direction is kept constant, peeling or deformation will occur unless the device is made to reduce the strain of the laminated product.

  In addition, this rolling operation has an effect of destroying a very thin oxide film generated at each metal layer interface and preventing a decrease in hydrogen permeation performance.

  Next, it cut | disconnects to a moderate magnitude | size and enters into an additional heat treatment process. The additional heat treatment is performed to complete the alloying of Ni and Ti. If the Ni layer remains as a single layer, the hydrogen permeation amount may be extremely deteriorated. Therefore, heat treatment is required again after the rolling process. The additional heat treatment is in a thin film state and does not require such a high temperature and a long time. As an optimum condition, one hour at 600 ° C. is appropriate.

  As described above, a hydrogen permeable membrane 21 having a composite multilayer structure using the composite core laminate 52 as a core material is obtained, and the membrane is attached to a predetermined position of the hydrogen generation / separation device 22.

  The operation of the hydrogen generation / separation apparatus 22 to which the hydrogen permeable membrane 21 having the composite multilayer structure configured as described above is attached will be described below.

  When the reaction chamber 25 is heated to 500 to 800 ° C. by the operation of the heating means 34, and hydrocarbon methane and water vapor are supplied to the reaction chamber 25 of the hydrogen generator / separator 22 from the supply port 31, the reforming catalyst 33 of the communicating Ni foam is formed. As shown in (Chemical Formula 1), methane is oxidized by water vapor, and the water vapor is reduced, and in addition to the generation of hydrogen and carbon dioxide, the hydrogen permeable membrane 21 is brought into contact with the Pd catalyst metal layer 52. The reaction is promoted by the catalytic action to generate hydrogen.

生成された水素は、水素透過膜２１の触媒金属層５３のＰｄ触媒により、水素分子が水素原子に解離され、複合多層構造の水素透過膜２１内に固溶される。触媒金属層５３の表面層は１００％のＰｄ濃度層であり触媒能力は非常に高く維持されている。

The generated hydrogen is dissociated into hydrogen atoms by the Pd catalyst of the catalytic metal layer 53 of the hydrogen permeable membrane 21 and is dissolved in the hydrogen permeable membrane 21 having a composite multilayer structure. The surface layer of the catalytic metal layer 53 is a 100% Pd concentration layer, and the catalytic ability is kept very high.

  The solid-solved hydrogen atoms flow toward the separation chamber 26 due to a difference in hydrogen concentration between the reaction chamber 25 and the separation chamber 26, pass through the Pd catalyst metal layer 53, and then the Mo fourth metal layer 51 and Ni. And the composite core laminate 52 in which Ti and Ta are densely laminated, pass through the fourth metal layer 51 at the Mo lowermost layer again, and again from the hydrogen atoms by the Pd catalyst of the catalytic metal layer 53 on the separation chamber 26 side. It is combined with hydrogen molecules and flows into the separation chamber 26 as hydrogen gas.

  At this time, the base of the hydrogen permeable membrane 21 having a composite multilayer structure is Ta having high hydrogen permeation performance, and hydrogen atoms are diffused very quickly. Even if a metal is prone to hydrogen embrittlement, it is relatively hydrogen brittle from both sides. Since the alloy layer made of Ti and Ni layer which is strong to protect is protected, hydrogen embrittlement is suppressed, and Ni which is difficult to pass hydrogen usually has improved hydrogen permeation amount by alloying with Ti having a large amount of hydrogen solid solution.

  Furthermore, since the catalytic metal layer 53 on the separation chamber 26 side is a 100% concentration Pd catalyst, the bonding from hydrogen atoms to hydrogen molecules is also performed quickly.

  If the surface is only a Pd metal with a catalyst layer and the center is only a base metal monolayer such as Ta as in the conventional example, mutual diffusion between Pd and Ta is caused by heating for a long time at 500 ° C. to 800 ° C. Gradually, Ta is deposited on the surface of the Pd layer, and an oxide film of Ta is formed on the surface layer, so that the hydrogen permeable film is extremely deteriorated. Further, Ta metal is a metal that is relatively easy to be hydrogen embrittled, and due to temperature change caused by operation and stop of the apparatus, the strength deteriorates due to hydrogen embrittlement, and the film cannot be self-supported and is destroyed.

  However, in this embodiment, the alloying layer of Ti and Ni protects the hydrogen embrittlement of the Ta layer of the base metal, so that the hydrogen embrittlement is suppressed for a long time.

  Mo is a metal that is difficult to form a metal hydride, has an effect of suppressing interdiffusion between Ta and Pd, and not only suppresses the precipitation of Ta element on the surface of the Pd coating layer, but also in the Ta layer. The diffusion of Mo has the effect of suppressing the hydrogen embrittlement of Ta.

  Next, the other mixed gas remaining in the reaction chamber 25 flows downstream on the discharge port 32 side, generates hydrogen gas by the same reaction, and similarly flows into the separation chamber 26 through the hydrogen permeable membrane 21.

  That is, when flowing from the supply port 31 to the discharge port 32, hydrogen sequentially flows out from the reaction chamber 25 through the hydrogen permeable membrane 21 having a composite multilayer structure, so that the hydrogen gas concentration of the flowing gas does not reach an equilibrium state even downstream. The hydrogen gasification reaction of (Chemical Formula 1) is performed smoothly, and in the vicinity of the discharge port 32, most of the circulating gas is discharged as carbon dioxide.

  Normally, the hydrogen ratio of the flow gas increases as it goes downstream, reaches an equilibrium state, and no longer reacts. However, in the reaction chamber 25, the hydrogen gas moves to the separation chamber 26, so the reaction continues. Done.

  As can be seen from this description, Pd constituting the catalytic metal layer 53 has a catalytic function for promoting dissociation / recombination of hydrogen and a function for permeating hydrogen. Further, Mo constituting the second metal layer 49 with the reformed metal and Ta constituting the first metal layer 48 with the base metal have a function of permeating hydrogen, and the hydrogen permeation performance of Ta is Pd. This is much better than the hydrogen permeation performance.

  In the present embodiment, since a sleeve gas such as water vapor is introduced into the separation chamber 26 from the introduction port 39 and flows through the separation chamber 26, the hydrogen accumulated in the spacer 46 portion of the hydrogen permeable membrane 21 having the composite multilayer structure is washed away. The hydrogen concentration in the vicinity of the Pd layer of the catalytic metal layer 53 does not increase, and a pressure partial pressure difference always occurs, so that smooth hydrogen diffusion movement is performed in the reaction chamber 25 and the separation chamber 26.

  Further, in the present embodiment, Ta is adopted as the first metal layer 48 of the base metal, but any metal plate having a high hydrogen permeability coefficient can be applied, and in particular, transition metals such as Ta, Nb, V, And their alloys are effective and are not limited to Ta.

  In the present embodiment, as the material of the peelable sheets 85a and 85b, carbon fiber felt (Nihon Carbon Co., Carboron, GF-20-2F) purified at about 2000 ° C. was used. Use of silica fiber non-woven fabric (Advantech Toyo Co., Ltd., silica fiber filter paper, QR-100) that has been highly purified at a temperature of ℃ or higher is good because of the pressure applied to the appropriate bonding interface in terms of surface compactness, and Graphite (Nihon Carbon Co., Nika Film, FL-300SH) purified at about 2000 ° C. has the same effect, does not generate gas due to heat, is elastically deformed by pressurization, and the first metal plate 79 and Any material can be used as long as it has good releasability from the second metal plate 80, the catalyst metal plate 83, and the pressurizing flat plate jigs 77a and 77b, and is not limited to the felt of carbon fiber. .

  In addition, although Ni is used as the second metal in which the second metal layer 49 has a small amount of hydrogen solid solution and is difficult to form a metal hydride, Co may be used as another versatile metal.

  Further, although Ti is adopted as the third metal layer 50 having a large hydrogen solid solution amount, a metal having Zr and Hf among the transition metal elements of the group IVA may be used as a metal having the same effect.

  Further, Mo is used as the fourth metal layer 51 having a low solid solubility limit with Pd, but the same effect is exhibited even when Cr and W, which are VIA group transition metals, are used.

  Further, although the Ti metal element ratio of the third metal layer 50 is made equal to the number of Ni metal elements of the second metal layer 49, even when the element ratio is 0.8 to 1.2, protection to prevent hydrogen embrittlement As a layer, an appropriate hydrogen permeation amount is maintained, so that the element ratio is not limited to 1: 1.

  Further, the ratio of Ni in the second metal layer 49 to the Ta element in the first metal layer 48 is 4.5%, but if it is a laminate corresponding to 1% to 30%, the hydrogen embrittlement effect and the hydrogen permeation performance Therefore, it is not limited to 4.5%.

  The Mo ratio of the fourth metal layer 51 with respect to Ta of the first metal layer 48 is 2.3% in terms of element ratio, but even with a distribution corresponding to 0.1% to 10%, the effect of suppressing mutual diffusion It maintains moderate hydrogen permeation performance.

  In the present embodiment, the method of forming the catalyst metal layer 53 using a Pd metal plate and simultaneously forming the composite core laminate 52 by diffusion bonding on the upper and lower sides of the composite core laminate 52 has been introduced. However, only the composite core laminate is formed. After that, as the catalyst metal layer forming step, any one of vacuum deposition, sputtering, and ion plating may be used.

  In addition, the additional heat treatment step is performed after the cutting step, but the additional heat treatment may be performed in a single direction even after cutting to a predetermined size.

  As described above, in the composite multilayer structure hydrogen permeable membrane 21 and the manufacturing method thereof according to the present embodiment, the first metal layer 48 of the base metal is reinforced by the second metal layer 49 strong against hydrogen embrittlement, and the second metal The layer 49 is the third metal layer 50, and the hydrogen permeable film 21 maintaining the hydrogen permeation performance is obtained by increasing the amount of hydrogen solid solution.

  Further, a fourth metal layer 51 that is difficult to diffuse Pd is formed between the catalytic metal layer 53 of Pd and the first metal layer 48, and mutual diffusion between the first metal layer 48 and the catalytic metal layer 53 is performed. Membranes that maintain the catalytic function of the surface layer, suppress hydrogen embrittlement, are multi-layered, have no pinholes even when rolled thin, have high permeation separation performance of high-purity hydrogen, and have a high-performance hydrogen permeation amount Can be provided.

  As described above, the hydrogen permeable membrane of the composite multilayer structure according to the present invention is used not only in the field of fuel cells using the hydrogen permeable membrane, but also for hydrogen generator for gas chromatograph analysis and surface modification in a semiconductor manufacturing factory. It can be used not only for hydrogen generators that are used, but also for promoting reaction kettles that have a reaction that generates hydrogen as an intermediate substance, and can also be used effectively for making equipment such as hydrogen generators inexpensively. .

1 is a schematic configuration diagram of a hydrogen generation / separation device incorporating a hydrogen permeable membrane having a composite multilayer structure according to Embodiment 1 of the present invention. Enlarged sectional view of the hydrogen permeable membrane having the composite multilayer structure of the embodiment Schematic cross-sectional configuration diagram showing a diffusion bonding apparatus for diffusion bonding a metal plate used for manufacturing a hydrogen permeable membrane having a composite multilayer structure of the embodiment The expanded sectional view which shows the press member of the diffusion bonding apparatus in the embodiment Sectional drawing in the rolling process state of the rolling mill used for manufacture of the hydrogen permeable film of the composite multilayer structure of the embodiment Process drawing which shows the manufacturing process of the hydrogen permeable membrane of the composite multilayer structure of the embodiment Expanded cross-sectional view of a conventional hydrogen permeable membrane Perspective view of a conventional hydrogen permeable membrane Perspective view of a tube using a conventional hydrogen permeable membrane

Explanation of symbols

DESCRIPTION OF SYMBOLS 21 Hydrogen permeable film of composite multilayer structure 48 1st metal layer 49 2nd metal layer 50 3rd metal layer 51 4th metal layer 52 Composite core laminated body 53 Catalytic metal layer 54 Sandwich body 79 1st metal plate 80 2nd metal plate 81 Third metal plate 82 Fourth metal plate 83 Catalyst metal plate 84 Laminated product

Claims (18)

  A laminate comprising a first metal layer having a high hydrogen permeation performance, a second metal layer having a small hydrogen solid solution amount and difficult to form a metal hydride, and a third metal layer having a large hydrogen solid solution amount, and comprising the laminate A hydrogen permeable membrane having a composite multilayer structure in which a catalytic metal layer of Pd or Pd alloy is formed on both sides of a body.   2. The hydrogen permeable membrane having a composite multilayer structure according to claim 1, wherein a fourth metal layer having a solid solubility limit lower than that of Pd is provided in the uppermost lower layer of the laminate.   The hydrogen permeable membrane having a composite multilayer structure according to claim 1 or 2, wherein the second metal layer and the third metal layer are laminated so as to be in direct contact with each other.   The hydrogen permeable membrane of a composite multilayer structure according to any one of claims 1 to 3, wherein a third metal layer is interposed between the first metal layer and the second metal layer.   The hydrogen permeable membrane having a composite multilayer structure according to any one of claims 2 to 4, wherein a second metal layer is formed between the third metal layer and the fourth metal layer.   6. The composite multilayer structure according to claim 1, wherein the laminate has two or more sandwich bodies in which the first metal layer is sandwiched between the alloy formation layers of the second metal layer and the third metal layer. Hydrogen permeable membrane.   The hydrogen of the composite multilayer structure according to any one of claims 1 to 6, wherein the metal element ratio of the third metal layer is an element ratio of 0.8 to 1.2 with respect to the number of metal elements of the second metal layer. Permeable membrane.   The hydrogen permeable membrane having a composite multilayer structure according to any one of claims 1 to 7, wherein a ratio of the second metal layer to the first metal layer corresponds to 1% to 30% in terms of an element ratio.   The composite multilayer structure according to any one of claims 2 to 8, wherein the ratio of the fourth metal layer to the first metal layer is configured with an allocation corresponding to 0.1% to 10% in terms of element ratio. Hydrogen permeable membrane.   The hydrogen permeation of the composite multilayer structure according to any one of claims 1 to 9, wherein the first metal layer having a high hydrogen permeation performance is a high melting point transition metal VA metal having a body-centered cubic structure or an alloy thereof. film.   The first metal layer having high hydrogen permeation performance is one of Ta, Nb, V, Ta alloy, Nb alloy, and V alloy, which are high melting point transition metals having a body-centered cubic structure. A hydrogen permeable membrane having a composite multilayer structure according to claim 1.   The composite according to any one of claims 1 to 11, wherein either Ni or Co is used from the group VIII transition metal elements as the second metal layer having a small amount of hydrogen solid solution and difficult to form a metal hydride. Multi-layer hydrogen permeable membrane.   The composite multilayer structure hydrogen according to any one of claims 1 to 12, wherein any of Ti, Zr, and Hf is used as a third metal layer having a large hydrogen solid solution amount from a transition metal element of group IVA. Permeable membrane.   The composite multilayered structure hydrogen according to any one of claims 1 to 13, wherein any one of Cr, Mo, and W, which are transition metals of group VIA, is used as the fourth metal layer having a low solid solubility limit with Pd. Permeable membrane.   Lamination by stacking a first metal plate made of a base metal with high hydrogen permeation performance, a second metal plate having a small hydrogen solid solution amount and difficult to form a metal hydride, and a third metal plate having a large hydrogen solid solution amount. A diffusion bonding step in which the laminated product is diffusion bonded by heat and pressure to form a diffusion bonded product, a rolling step in which the diffusion bonded product is rolled to a predetermined thickness to obtain a rolled composite core laminate, and the composite core The manufacturing method of the hydrogen permeable film of a composite multilayer structure which has a catalyst metal layer formation process which forms the catalyst metal layer which consists of Pd or a Pd alloy on both surfaces of a laminated body.   16. The production of a hydrogen permeable membrane having a composite multilayer structure according to claim 15, wherein any one of vacuum vapor deposition, sputtering, and ion plating is used in the catalyst metal layer forming step of forming a catalyst metal layer made of Pd or a Pd alloy. Method.   A first metal plate made of a base metal with high hydrogen permeation performance, a second metal plate with a small amount of hydrogen solid solution that makes it difficult to form a metal hydride, a third metal plate with a large amount of hydrogen solid solution, and a lowermost layer if necessary Laminating process in which Pd and a fourth metal plate having a low solid solubility limit are laminated to form a laminated product, and a laminated product with a catalytic metal, in which a catalytic metal plate made of Pd or Pd alloy is laminated on the upper and lower surfaces of the laminated product A forming step, a diffusion bonding step in which the laminate with catalyst metal is diffusion bonded by heat and pressure to form a diffusion bonded product, and a rolling step in which the diffusion bonded product is rolled to a predetermined thickness to form a rolled composite core laminate. A method for producing a hydrogen permeable membrane having a composite multilayer structure.   The additional heat treatment for alloying the second metal layer and the third metal layer is performed after the rolling step of rolling the diffusion bonded product to a predetermined thickness to form a rolled composite core laminate. A method for producing a hydrogen permeable membrane having a composite multilayer structure according to claim 1.

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