JP2008246314A - Hydrogen separator and fuel cell - Google Patents

Abstract

A hydrogen separation device and a fuel cell capable of realizing high durability in a hydrogen separation section capable of selectively separating hydrogen without reducing the hydrogen permeability of the hydrogen separation section at an attached site. To provide.
A cylindrical or plate-like porous support that opens at both ends or one end, and a hydrogen permeable membrane that selectively permeates hydrogen gas formed on the inner surface and / or outer surface of the porous support. And a hydrogen separation portion that is connected to the hydrogen separation portion via a seal member, and the hydrogen separation portion has a thickness that is not in contact with the seal member. A hydrogen separator characterized by being 0.1 to 30 mm larger than the thickness of the part to be contacted.
[Selection] Figure 1

Description

  The present invention relates to a hydrogen separation device and a fuel cell, and more particularly to a hydrogen separation device and a fuel cell in which the durability of a seal member is excellent and hydrogen can be selectively separated to obtain high-purity hydrogen.

  In Patent Document 1, “a seal unit attached to the outer periphery of a pipe, comprising: an expanded graphite sealing material; and a pair of connecting materials, wherein the sealing material in the sealing material Each of the pair of connecting members and at least one of the surfaces in contact with the pipe axial direction are formed so as to protrude toward the outer peripheral surface of the pipe, and the ... on the side of the connecting member facing the contact surface. "Seal unit" (see claim 1 of Patent Document 1) is formed so that the surface that comes into contact with the seal material becomes recessed toward the outer peripheral surface of the pipe, and this seal unit is used. An apparatus capable of selectively separating hydrogen is also described (see claim 7 of Patent Document 1).

  Patent Document 2 states that “a cylindrical reforming catalyst / support and a hydrogen permeable membrane are arranged on the outer peripheral surface of the reforming catalyst / support, A hydrogen production apparatus characterized in that a reformed gas is generated by a cylindrical reforming catalyst / support through a raw material gas, and the reformed gas is purified by a hydrogen permeable membrane to produce high-purity hydrogen "( Patent Document 2 (see claim 1)).

  By the way, there is a problem that the hydrogen permeable membrane is often damaged when the seal unit having the hydrogen permeable membrane and the cylindrical reforming catalyst / support are attached to the hydrogen production apparatus with an attachment jig or during the use of the hydrogen production apparatus. It was happening.

Japanese Patent Application Laid-Open No. 2004-1987 JP 2004-149332 A

  The problem to be solved by the present invention is that, in a hydrogen separation part capable of selectively separating hydrogen, the attached portion can realize high durability without reducing the hydrogen permeability of the hydrogen separation part. It is to provide a hydrogen separator and a fuel cell.

  Another object of the present invention is to provide a fuel cell that can efficiently separate hydrogen and is provided with the separated hydrogen.

As means for solving the problems,
[Claim 1] A cylinder-shaped porous plate having both ends or one end opened, or a plate-shaped porous support, and a hydrogen-permeable membrane formed on the inner surface and / or outer surface thereof for selectively permeating hydrogen gas And a mounting part for connecting the hydrogen separation part via a seal member, and the hydrogen separation part has a thickness of a part in contact with the seal member in the seal member. A hydrogen separator characterized by being 0.1 to 30 mm larger than the thickness of the non-contacting part,
Claim 2 is the hydrogen separator according to claim 1, wherein the seal member is formed of expanded graphite.
Claim 3 is the hydrogen separator according to claim 1 or 2, wherein a part or all of the hydrogen permeable membrane is palladium or an alloy containing palladium.
According to a fourth aspect of the present invention, there is provided a fuel cell characterized in that electric power is taken out using hydrogen separated by the hydrogen separator according to any one of the first to third aspects as a fuel.

  In the hydrogen separation part capable of selectively separating hydrogen, the thickness of the portion attached to the attachment part is formed to be larger by 0.1 mm or more. In addition, it is possible to provide a hydrogen separator that can achieve high durability without further reducing the hydrogen permeability.

  In addition, the present invention can provide a fuel cell that can efficiently separate hydrogen and is provided with the separated hydrogen.

  The hydrogen separator provided in the hydrogen separator of the present invention can selectively separate hydrogen from a gas (hereinafter sometimes referred to as “source gas”) supplied to the hydrogen separator, or the source gas is hydrogen. Hydrogen can be generated by reacting or decomposing in the separation section, and the hydrogen can be selectively collected. Examples of the gas supplied to the hydrogen separator include hydrogen gas, carbon dioxide gas, carbon monoxide, methane, and water vapor. However, these gases may be supplied in a mixed state.

  The porous support that can be used in this hydrogen separation device allows gas to flow inside and outside, does not react with the source gas, does not change with the source gas, and can support the hydrogen permeable membrane. , Formed of various materials. For example, examples of the material include inorganic oxide, carbon, and inorganic nitride. Among the materials, examples of the inorganic oxide include aluminum oxide, silica, silica-alumina, mullite, cordierite, zirconia, stabilized zirconia, and porous glass. Further, the materials can be used singly, mixed or combined.

  The porous support reacts when the gas supplied to the hydrogen separator comes into contact, is decomposed, or is sometimes referred to as a “catalytic function” that can generate hydrogen by steam reforming. ). The porous support can be formed by mixing or combining the above materials and a material having a catalytic function. When a porous support having a catalytic function is formed, for example, a porous support to which nickel used for steam reforming of hydrocarbons is added, for example, a mixture of nickel and yttria stabilized zirconia is used. A porous sintered body having a main component (sometimes referred to as “Ni-YSZ cermet”), porous ceramic added with nickel, porous glass added with nickel, or the like can be used. When a synthetic gas or a water gas is used as the gas to be supplied, a catalytic function can be added by adding an iron and / or chromium component or the like to the porous support. What is necessary is just to select suitably the component which adds a catalyst function with the kind etc. of the gas supplied. However, when the supplied gas needs to generate hydrogen by the catalytic function, a porous support that simply allows the supplied gas to pass therethrough and a catalyst layer having a catalytic function capable of generating hydrogen are provided. It can also be formed separately. It is preferable that the catalyst layer is also porous like the porous support.

  The porous support, the catalyst layer, and the reinforcing portion described later of the hydrogen separator of the present invention are porous, and when formed, for example, graphite powder or corn starch that can be used as a pore-forming agent is mixed. By sintering, a porous support, a catalyst layer, and a reinforcing part that are porous can be obtained.

  Further, by controlling the porosity and pore diameter of the porous support, the catalyst layer, and the reinforcing portion, their strength, gas permeability and the like can be adjusted.

  The porosity of the porous support, the catalyst layer, and the reinforcing portion is preferably 10 to 85%. When the porosity is less than 10%, the raw material gas does not flow quickly through the porous support and the catalyst layer, and the pressure loss may increase, and in particular, the catalytic function capable of steam reforming of hydrocarbons In the case of using a porous support tube provided with or forming a catalyst layer, the hydrocarbon may not be sufficiently reformed. On the other hand, when the porosity exceeds 85%, the strength of the porous support tube, the catalyst layer, and the reinforcing portion may be lowered. In the present invention, the porosity is a value measured by the Archimedes method. The porosity of the porous support tube, the catalyst layer, and the reinforcing portion is appropriately determined based on the strength of each member, the pressure applied to the porous support tube, the catalyst layer, and the reinforcing portion provided by the supplied gas, and the like. The

  The average pore diameter of the porous support tube, the catalyst layer, and the reinforcing portion is preferably 0.05 to 30 μm. When the average pore diameter is less than 0.05 μm, the raw material gas does not flow quickly through the porous support tube and the catalyst layer, and the pressure loss may increase. In particular, when a porous support having a catalytic function capable of steam reforming hydrocarbons is used or when a catalyst layer is formed, the raw material gas may not be sufficiently reformed. On the other hand, if the average pore diameter exceeds 30 μm, there is a risk that sufficient strength of the porous support, the catalyst layer, and the reinforcing portion cannot be maintained. In addition, defects such as voids may occur in the hydrogen permeable membrane supported by the porous support, and the hydrogen permeability of the hydrogen permeable membrane may decrease. In this invention, the average pore diameter was calculated by observing the surface with an electron microscope, for example, a scanning electron microscope (SEM) and the like, by arithmetically averaging the opening diameter obtained by approximating the opening of the pore to a circle. Value.

  In order to control the porosity and average pore diameter of the porous support, catalyst layer and reinforcing part within the above ranges, the particle size, particle size distribution and / or calcination temperature of the powder used as the material forming them are appropriately adjusted. do it.

  The hydrogen permeable membrane used in the hydrogen separator according to the present invention can selectively permeate hydrogen. The hydrogen permeable membrane is formed on the surface of the porous support, and when the porous support is cylindrical, it is formed on the inner surface and / or the outer surface of the porous support. When a hydrogen permeable membrane is formed on the inner surface of the porous support, a gas that does not need to go through steps such as reaction, decomposition or modification of the raw material gas by a catalytic function, such as hydrogen gas, or A mixed gas of hydrogen gas and other gas is preferable.

  The entire surface of the porous support used in the present invention is preferably covered with a hydrogen permeable membrane. This is because if the surface of the porous support is not sufficiently covered with the hydrogen permeable membrane and the porous support is exposed, components other than hydrogen gas leak from the exposed portion and are collected as hydrogen gas. As a result, the purity of hydrogen in the gas is lowered. The material of the hydrogen permeable membrane that can be employed in the hydrogen separation apparatus of the present invention is not limited as long as it is a membrane that selectively permeates hydrogen gas in a gas. Palladium, palladium alloys, “inorganic chemical nomenclature IUPAC Metals such as Group 5 elements of the periodic table described in “1990 Recommendation” (translated on March 26, 1993, Author Kazuo Yamazaki) and alloys containing these elements are preferably used. Examples of the Group 5 element include V, Nb, and Ta. Examples of the palladium alloy and the metals other than the Group 5 element contained in the alloy containing the Group 5 element include, for example, “Inorganic Chemical Nomenclature IUPAC 1990 Recommendation” (published on March 26, 1993) Group 3 elements (including lanthanoid elements), group 8 elements, group 9 elements, group 10 elements, group 11 elements or combinations of two or more of these in the periodic table described in Kazuo Yamazaki) It is done. The group 3 element of the periodic table can include Y, the lanthanoid element can include Ce, Sm, Gd, Dy, Ho, Er, Yb, and the like, the group 8 element can include Ru, Examples of the Group 9 element include Rh and Ir, examples of the Group 10 element include Pt, and examples of the Group 11 element include Cu, Ag, and Au.

  The hydrogen permeable membrane is formed on the outer surface or inner surface of the porous support by, for example, a vacuum deposition method, an electroless plating method, a sputtering method, or the like. The thickness of the hydrogen permeable membrane is determined by the required hydrogen separation performance, for example, the hydrogen gas permeation rate and gas selectivity, and the mechanical strength of the hydrogen permeable membrane, and is preferably adjusted to 1 to 30 μm, for example.

  The attachment part is attached with the hydrogen separation part. The shape of the attachment part is a hydrogen separation part and a member used appropriately other than the attachment part, for example, a hydrogen gas deriving part for deriving the separated hydrogen gas, and a residual gas for deriving the gas after separating the hydrogen gas from the source gas It is appropriately selected according to the structure, shape, etc. of the lead-out part. Examples of the shape of the attachment portion include a plate shape, a disk shape, a flange shape, and a cylindrical shape. Further, the size of the attachment portion is determined according to the size of the hydrogen gas lead-out portion or the like. In addition, it is preferable that an attachment part is not porous, and is dense and does not have gas permeability.

  In the hydrogen separator according to the present invention, the hydrogen separator and the attachment are joined via a seal member.

  In a normal case, in the hydrogen separator, the porous support is fixed to a predetermined part, and therefore a seal member is used to fix the porous support to the predetermined part. The seal member is formed of a material that can absorb the pressure without the pressure applied when the porous support is fixed to the predetermined portion being directly applied to the porous support. Is required. As physical properties of the material that can form the seal member that can meet this requirement, the compression rate (based on JIS-R3453) is 10 to 90%, and the restoration rate (based on JIS-R3453). The oxidation start temperature (the temperature when the weight is reduced by 1% by heating in air) is 400 ° C. or higher. Specifically, for example, expanded graphite is used as the seal member. Expanded graphite has high sealing performance in addition to the high heat resistance inherent in graphite. The expanded graphite is obtained by expanding natural graphite by oxidizing it with an oxidizing agent such as concentrated sulfuric acid or nitric acid. By compressing the expanded graphite, it is possible to obtain expanded graphite that is preferable as a seal member used in the hydrogen separator of the present invention.

  In one aspect of the hydrogen separator according to the present invention, the thickness of a portion of the hydrogen separator that contacts the seal member is less than the thickness of a portion that does not contact the seal member. 1 to 30 mm larger, more preferably 0.3 to 10 mm larger, and particularly preferably 0.3 to 5 mm larger. If the difference between the thickness of the portion that contacts the seal member and the thickness of the portion that does not contact the seal member is less than 0.1 mm, durability may not be improved, and if it exceeds 30 mm The hydrogen separation part becomes large, which is not preferable from the viewpoint of apparatus miniaturization.

  A portion where the hydrogen separation portion and the seal member are in contact with each other is more likely to be loaded than a portion where the hydrogen separation portion and the seal member are not in contact with each other due to a volume change of the hydrogen separation portion caused by heat or the like. The strength can be increased by increasing the thickness of the hydrogen separator so that the load caused by this volume change does not destroy the hydrogen separator, particularly the hydrogen permeable membrane. On the other hand, when the thickness of the hydrogen separation part is increased, the gas permeation amount may be reduced depending on the thickness. Therefore, in the hydrogen separation part of the hydrogen separator according to the present invention, the thickness of the portion that contacts the seal member is formed larger than the thickness of the portion that does not contact the seal member. The portion where the thickness is increased may be hereinafter referred to as “reinforcing portion”. If the reinforcing part is made of the same material as the porous support, it is not necessary to prepare and manufacture a material different from the porous support, which is efficient. When the porous support is cylindrical, the reinforcing portion can be formed outside or inside the porous support. The reinforcing part and the porous support may be formed separately, and the reinforcing part and the porous support are bonded in the process of forming the hydrogen separation part. If possible, the reinforcing portion and the porous support may not be formed separately but may be formed integrally.

  Therefore, in the hydrogen separation device of the present invention, the hydrogen separation part is attached via the seal member, and the reinforcement part is formed to be larger by 0.1 to 30 mm, so that the volume of the hydrogen separation part changes due to heat or the like. Even so, the sealing performance of the sealing member and the strength of the reinforcing portion can prevent the hydrogen separating portion from being broken due to the load applied to the hydrogen separating portion.

  When the porous support tube contains a metal and the hydrogen permeable membrane is formed in contact with the outer surface or the inner surface of the porous support tube, depending on the use environment of the hydrogen separator of the present invention, the porous support tube may be porous. The metal component contained in the porous support tube penetrates into the hydrogen permeable membrane and reduces the permeability of the hydrogen permeable membrane, or conversely, the palladium used in the hydrogen permeable membrane is nickel in the porous support. It is conceivable that the hydrogen permeable membrane diffuses into the porous body while being dissolved in the solution, thereby reducing the hydrogen permeability of the hydrogen permeable membrane. When using the hydrogen separation device of the present invention in an environment where such a state may occur, the state is prevented by providing a porous barrier layer between the porous support tube and the hydrogen permeable membrane. Can do. However, in an environment where the above state does not occur, for example, in a mode in which the catalyst layer is provided separately from the porous support tube, it is not necessary to provide a barrier layer.

  The barrier layer is formed of a porous material that prevents mutual diffusion between the metal component of the material forming the porous support tube and the metal component of the material forming the hydrogen permeable membrane and allows gas to flow therethrough. For example, it is formed of an inorganic oxide or the like. Examples of the inorganic oxide include zirconia, stabilized zirconia, partially stabilized zirconia, aluminum oxide, magnesium oxide, lanthanum calcium, lanthanum chromite, lanthanum strontium, and mixtures or compounds thereof. In many cases, the barrier layer is formed as a porous tube excluding the catalyst component of the porous support tube having a catalytic function, such as nickel described above. The barrier layer may be in a porous state when the hydrogen separation device of the present invention is used, and may not necessarily be in a porous state when the barrier layer is formed.

  The barrier layer is formed on the porous support tube having a catalytic function by using a material such as zirconia as described above, for example, by a dip coating method, a spray spraying method, a printing method, or the like. Moreover, you may remove the catalyst metal in the porous support tube which has a catalyst function by a dissolution removal method. The catalyst metal dissolution and removal method is a method in which a metal contained in a porous support tube having a catalytic function is eluted from a portion where a barrier layer of the porous support tube is to be formed using a solvent or a reactant. The solvent and the reactant used at this time are not particularly limited as long as the metal can be eluted. For example, when a porous support tube having a catalytic function is formed of the Ni-YSZ cermet, Ni present in the vicinity of the surface of the porous support tube can be eluted using an acid such as sulfuric acid or hydrochloric acid. it can. The thickness of the barrier layer is not particularly limited as long as the material components that form the porous support tube and the hydrogen permeable membrane do not diffuse with each other. For example, the barrier layer is adjusted to 5 to 100 μm. If the thickness of the barrier layer is less than 5 μm, mutual diffusion of the material components forming the porous support tube and the hydrogen permeable membrane may not be prevented. On the other hand, if the thickness exceeds 100 μm, the smoothness of the hydrogen permeable member May impede proper hydrogen permeation or reduce the hydrogen production function of the porous support tube.

  In the above description, the hydrogen separation part is described as a cylindrical shape. However, the shape of the hydrogen separation part is, for example, a polygonal cylinder, a curved or bent cylinder as long as the object of the present invention can be achieved. It may be formed in a shape, or a form formed in a plate shape may be adopted.

  The hydrogen separator according to the present invention will be described below with reference to the drawings. Although FIGS. 1-6 has shown one Example of the hydrogen separator of this invention, as long as it has the structure of this invention, the hydrogen separator of this invention is not limited to the Example shown by a figure. Moreover, in FIGS. 1-5, since the porous support body is formed in the cylinder shape, it may be called a porous support tube.

  A hydrogen separator 1 that is an example of the present invention shown in FIG. 1 includes a hydrogen separator 2 and an attachment 3. The hydrogen separator 2 includes a porous support tube 4 and a hydrogen permeable membrane 5 formed on the outer surface thereof. Since the porous support tube 4 shown in FIG. 1 has a bottomed cylindrical shape and is porous, for example, gas can flow from the inside to the outside of the porous support tube 4, and hydrogen permeation can be performed. The membrane 5 is supported.

  The reinforcing portion 7 provided in the hydrogen separation apparatus of the present invention shown in FIG. 1 is formed so that the attachment portion 3 and the seal member 10 do not protrude from the edge line 11 formed at the end surface in contact with the hydrogen separation portion 2. Has been. This is because the portion where the reinforcing portion 7 is formed has a large thickness of the hydrogen separation portion 2 and the gas permeation amount is smaller than the portion where the reinforcing portion 7 is not formed and the thickness is small. This is preferable because a state where the required gas permeation amount is not satisfied can be prevented.

  A source gas introduction unit 12 is inserted inside the hydrogen separation unit 2 so that the source gas can be supplied to the hydrogen separation unit 2. In addition, in the hydrogen separation apparatus shown in FIG. 1, as a member provided as appropriate, a hydrogen gas deriving unit (not shown in FIGS. 2 to 5) for deriving the separated hydrogen gas and hydrogen gas from the source gas are used. A residual gas deriving section (not shown in FIGS. 2 to 5) for deriving the gas after separation is provided.

  In the hydrogen separator shown in FIG. 2, the porous support tube 4 that simply passes the raw material gas and the catalyst layer 6 that has a catalytic function capable of generating hydrogen are separately formed. 1 is the same as the embodiment shown in FIG. 1 except for this difference.

  In the hydrogen separation apparatus shown in FIG. 3, the hydrogen permeable membrane 5 is formed on the inner surface of the porous support tube 4, which is a difference from the hydrogen separation apparatus shown in FIG. Otherwise, the embodiment is the same as in FIG. The raw material gas in the hydrogen separator 1 shown in FIG. 3 is a gas that does not need to undergo a process such as reaction, decomposition, or reforming, such as hydrogen gas or simply a mixed gas of hydrogen gas and another gas. Preferably there is.

  In the hydrogen separator shown in FIG. 4, the point that the reinforcing portion 7 is formed inside the porous support tube 4 is different from the hydrogen separator shown in FIG. 1, except for this difference. It is an embodiment similar to FIG.

  In the hydrogen separator shown in FIG. 5, the point that the porous support tube 4 has a cylindrical shape with both ends opened is the difference from the hydrogen separator shown in FIG. Is an embodiment similar to FIG. Since it has a cylindrical shape with both ends opened as shown in FIG. 5, it is not necessary to provide a member shown as the source gas introduction part 12 in FIG. 1, and the porous support tube 4 itself introduces the source gas. It becomes a member.

  An embodiment in which the porous support is formed in a plate shape is shown in FIG. In FIG. 6, the hydrogen separation part 2 is formed in a plate shape. Specifically, the reinforcing part 7 is provided at the edge of the plate-like porous support body 4, and the hydrogen permeable membrane 5 is provided in the porous support body 4. Is formed on the surface. Further, a pair of frames 13 are provided outside the hydrogen separator 2, and the frame 13 faces the raw material gas inlet 12 and the hydrogen permeable membrane 5 on the side facing the porous support 4. A hydrogen gas lead-out portion 8 is provided on the side where the head is located. The frame 13 is integrated by an appropriate method such as pressure bonding, adhesion, or screw contact. In FIG. 6, a seal member 10 is disposed between the frame body 13, the reinforcing portion 7, and the hydrogen permeable membrane 5, and the seal member 10 has a trapezoidal cross section instead of a rectangle. When the reinforcing member 7 and the frame 13 are pressed against the seal member 10 by using the seal member 10 having a shape as shown in FIG. 6, a force for pressing the seal member 10 in the vertical direction and the horizontal direction in FIG. 6 acts. In other words, even when the frame 13 is not in close contact, the hydrogen separation device 1 is obtained in which the sealing member 10 can prevent gas leakage. When the porous support of the hydrogen separator according to the present invention has a plate shape, the porous support may be, for example, a disk shape or a rectangular plate shape. In addition, it is preferable to change the shape of the seal member in accordance with the shape of the porous support and to provide the seal member along the edge of the porous support, so that gas leakage can be prevented.

  As another embodiment of the present invention, an example of a fuel cell equipped with the hydrogen separator of the present invention is shown in FIGS.

  A preferred embodiment of the fuel cell according to the present invention is formed by integrally forming the hydrogen separator and the power generator of the present invention. In addition to the hydrogen separator, the fuel cell has an anode layer, an electrolyte layer, and a cathode layer. Device. Such a fuel cell can be referred to as an integrated fuel cell. In an apparatus configuration in which a hydrogen separator and an electric power generation apparatus are integrated, it is preferable from the viewpoint of reducing the number of parts that the hydrogen permeable membrane described above is an anode in the electric power generation apparatus. An embodiment in which the porous support of the integrated fuel cell is formed in a cylindrical shape is shown in FIG. 7, and an embodiment in which the porous support is formed in a plate shape is shown in FIG.

  The fuel cell 14 shown in FIGS. 7 and 8 is preferably formed so that the hydrogen permeable membrane 5 of the hydrogen separator 2 described above has a function as an anode of the fuel cell 14. Note that the metal that can be used to form the hydrogen permeable film described above can form a hydrogen permeable film that also functions as an anode.

  Next, an electrolyte layer is provided on the surface of the hydrogen permeable membrane. This electrolyte layer can conduct and pass ionized hydrogen ions by the function of the anode of the hydrogen permeable membrane. The material that can form the electrolyte layer is not limited as long as hydrogen ions can pass therethrough. For example, a perovskite type material containing at least one selected from the group consisting of Ba, Sr, Ca, Ce, and Zr. A compound can be mentioned. The electrolyte layer can be formed by adding the perovskite compound together with a binder and a dispersant to a solvent to form a slurry, applying the slurry to the surface of the hydrogen permeable membrane by screen printing or the like, and then performing a heat treatment.

Next, a cathode layer is formed on the surface of the electrolyte layer. This cathode layer functions as a cathode of the fuel cell. The material that can form the cathode layer is Ag, Pt, Ph, or the formula A _1-X B _X CO ₃ (wherein A is a rare earth element and B includes one or more of Ba, Sr, and Ca). And C is an element including one or more of Co, Fe and Mn). Similarly to the electrolyte layer, the cathode layer can be formed by preparing a slurry containing a material and applying the slurry to the surface of the electrolyte layer by screen printing or the like, followed by heat treatment.

  The electrolyte layer and the cathode layer can also be formed by a sol-gel method or a vapor deposition method.

  In the laminated body composed of the hydrogen separator having the function as an anode, the electrolyte layer, and the cathode layer formed as described above, the hydrogen permeable membrane 5 having the function as the anode layer as shown in FIGS. By providing a closed circuit between the cathode layer 16 and applying a load, it is possible to form the fuel cell 14 that extracts power. Further, as shown in FIGS. 7 and 8, the hydrogen permeable membrane 5 having a function as an anode of the fuel cell 14 is provided with a connection terminal 20 so that the terminal can be easily connected.

  When the fuel cell is formed in a cylindrical shape, a barrier layer, a hydrogen permeable membrane 5 and an electrolyte layer, which are appropriately provided outwardly by disposing a porous support tube 4 inside the tube as shown in FIG. 15 and the cathode layer 16 are arranged in this order, and electricity can be taken out by flowing a source gas inside the porous support tube 4 and a cathode gas such as air outside the cathode layer 16. Furthermore, the order of the layers to be arranged can be reversed, and the source gas can be circulated outside the porous support tube and the cathode gas can be circulated inside the cathode layer.

  The fuel cell according to the present invention is not limited to the integrated fuel cell. For example, the hydrogen separator according to the present invention and an anode layer, an electrolyte layer, and a cathode layer formed separately from the hydrogen separator. And a separate fuel cell having a power generation device including a laminate formed by stacking a gas supply line for supplying hydrogen gas extracted by the hydrogen separation device to the power generation device. An example of the separate fuel cell is shown in FIG. In FIG. 9, the hydrogen gas outlet 8 is connected to the power generator 17, and the cathode gas inlet 18 for introducing the cathode gas is also connected to the power generator 17, and the power generator 17 includes hydrogen gas and cathode gas. The anode layer 19, the electrolyte layer 15, and the cathode layer 16 that can extract electric power from the cathode are provided. The power generation device 15 has a function as a battery that can extract power from the supplied gas. The fuel cell 14 shown in FIG. 9 operates as follows. First, the hydrogen separated in the hydrogen separation unit 2 is supplied to the anode layer 19 side of the power generation device 17 by the hydrogen gas lead-out unit 8 appropriately provided with a ventilator or the like. Next, in the cathode gas introduction unit 18, for example, a cathode gas such as air is supplied to the cathode layer 16 side of the power generation device 17. Next, the power generation device 17 to which hydrogen and cathode gas are supplied can take out power with a connected circuit.

  A strength test was performed on the hydrogen separator of the hydrogen separator according to the present invention. Examples and comparative examples of the strength test are shown below.

Example 1
Zirconia in which 60 parts by mass of nickel oxide and 8 mol% of yttria are dissolved (hereinafter, zirconia in which yttria is dissolved) is sometimes referred to as “YSZ”, and in the case of 8 mol% being dissolved as “8YSZ”. ) 40 parts by mass were mixed. Further, graphite powder was mixed as a pore forming agent to obtain a mixture. This mixture is extruded to form a bottomed cylindrical tube (which will be referred to as a porous support tube) and a cylindrical tube having a larger outer shape and inner diameter than the bottomed cylindrical tube and open at both ends (referred to as a reinforcing portion). Will be molded). Porous support formed with NiO-YSZ cermet by adjusting the mixture into a paste and pasting together with the mixture in the paste so that the cylindrical tube is covered in the vicinity of the opening of the bottomed cylindrical tube and firing at 1400 ° C for 1 hour Got the tube. At this time, the thickness of the reinforcing part was 0.1 mm.

  The obtained porous support tube was subjected to reduction treatment at 600 ° C. for 3 hours in a hydrogen atmosphere to obtain a porous support tube having a catalytic function formed of Ni—YSZ cermet. Thereafter, the porosity and average pore diameter of the porous support tube were measured. The measured porosity was in the range of 10 to 85%, and the average pore diameter was 0.4 μm.

  8YSZ and a binder were added to ethanol to prepare a slurry. This slurry was coated with a barrier layer on the outer surface of the porous support tube by dip coating. The thickness of the barrier layer was 20 μm. The porous support tube covered with the barrier layer was dried.

  Next, a hydrogen permeable film was formed by an electroless plating method so as to cover the barrier layer. At this time, the opening of the porous support tube was sealed with a stopper and plated. In the electroless plating method performed here, first, the porous support tube was immersed in an aqueous hydrochloric acid solution of tin chloride dihydrate, washed, and then immersed in an aqueous hydrochloric acid solution of palladium chloride and washed three times. . Thereafter, the porous support tube was immersed in a plating solution containing ammonia water and an aqueous hydrazine solution to form a hydrogen permeable membrane. The film thickness of the hydrogen permeable membrane was 9 μm.

  The site | part in which the reinforcement part was formed was cut out as follows, and the fracture strength was measured. The part where the reinforcing part of the hydrogen separation part was formed was cut out to have a width of 5 mm in the radial direction, and the cut surface was precisely polished so as not to affect the measurement. The fracture strength of the annular body was measured by applying a load to the obtained annular body using an autograph AGS-5kND manufactured by Shimadzu Corporation. The measurement was performed by attaching a cylindrical jig to the autograph so that the load was not biased, and contacting the jig so that the load was evenly applied in one axial direction of the annular body. The measured breaking strength was divided by the length of the annular body in the axial direction to calculate the breaking load per unit length. The measurement was performed on 10 annular bodies, and the average value was calculated at 8 points excluding the calculated maximum and minimum values of the fracture load.

(Example 2)
A hydrogen separation part was formed in the same manner as in Example 1 except that the thickness of the reinforcing part was 0.3 mm, and the fracture strength was measured.

(Example 3)
A hydrogen separation part was formed in the same manner as in Example 1 except that the thickness of the reinforcing part was 0.6 mm, and the fracture strength was measured.

Example 4
A hydrogen separation part was formed in the same manner as in Example 1 except that the thickness of the reinforcing part was 0.9 mm, and the fracture strength was measured.

(Comparative Example 1)
A hydrogen separation part was formed in the same manner as in Example 1 except that the reinforcing part was not provided, that is, the thickness of the reinforcing part was set to 0 mm, and the fracture strength was measured.

(Comparative Example 2)
A hydrogen separation part was formed in the same manner as in Example 1 except that the thickness of the reinforcing part was 0.05 mm, and the fracture strength was measured.

  In addition to the breaking load, the strength ratio with respect to Comparative Example 1 in which the thickness of the reinforcing portion was 0 mm was also calculated. The results are shown in Table 1.

  Therefore, in the hydrogen separator according to the present invention, since the reinforcing portion is formed, the strength of the portion where the hydrogen separation portion contacts the seal member is high, and the hydrogen permeation performance of the portion where the hydrogen separation portion does not contact the seal member Can be held without lowering.

  In addition, since the hydrogen separation part is attached to the attachment part via a seal member, no gas leakage occurs when the hydrogen separation part undergoes a volume change due to heat or the like.

FIG. 1 is a sectional view showing an embodiment of the hydrogen separator according to the present invention. FIG. 2 is a cross-sectional view showing another embodiment of the hydrogen separator according to the present invention and showing a hydrogen separator, an attachment part, and a raw material gas introduction part. FIG. 3 is a cross-sectional view showing another embodiment of the hydrogen separator according to the present invention and showing a hydrogen separator, an attachment part, and a raw material gas introduction part. FIG. 4 shows another embodiment of the hydrogen separator according to the present invention, and is a cross-sectional view showing a hydrogen separator, an attachment part, and a raw material gas introduction part. FIG. 5 shows another embodiment of the hydrogen separator according to the present invention, and is a cross-sectional view showing a hydrogen separator, an attachment part, and a raw material gas introduction part. FIG. 6 is a sectional view showing another embodiment of the hydrogen separator according to the present invention. FIG. 7 is a cross-sectional view showing an embodiment of a fuel cell equipped with the hydrogen separator of the present invention. FIG. 8 is a cross-sectional view showing another embodiment of a fuel cell equipped with the hydrogen separator of the present invention. FIG. 9 is a cross-sectional view showing another embodiment of a fuel cell equipped with the hydrogen separator of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydrogen separator 2 Hydrogen separation part 3 Attachment part 4 Porous support body (porous support tube)
DESCRIPTION OF SYMBOLS 5 Hydrogen permeable film 6 Catalyst layer 7 Reinforcement part 8 Hydrogen gas derivation part 9 Residual gas derivation part 10 Seal member 11 Edge line 12 Raw material gas introduction part 13 Frame 14 Fuel cell 15 Electrolyte layer 16 Cathode layer 17 Electric power generation device 18 Cathode Gas introduction part 19 Anode layer 20 Connection terminal

Claims (4)

  It is provided with a porous support having a cylindrical shape that opens at both ends or one end, or a plate shape, and a hydrogen permeable membrane that is selectively formed on the inner surface and / or outer surface of the porous support to allow hydrogen gas to permeate therethrough. A hydrogen separation part, and an attachment part that couples the hydrogen separation part via a seal member, wherein the hydrogen separation part is a part in which the thickness of the part in contact with the seal member is not in contact with the seal member A hydrogen separator characterized by being 0.1 to 30 mm larger than the wall thickness.   The hydrogen separator according to claim 1, wherein the seal member is made of expanded graphite.   The hydrogen separator according to claim 1 or 2, wherein a part or all of the hydrogen permeable membrane is palladium or an alloy containing palladium.   The fuel cell which takes out electric power by making into use the hydrogen isolate | separated by the said hydrogen separation apparatus of any one of the said Claims 1-3 as a fuel.

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