JP2013022553A - Fluid separation material and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid separation material including sealing strength as well as excellent separation characteristics for fluid such as hydrogen, and to provide a method for manufacturing the same.SOLUTION: Glass particles are deposited around a rod 30 by using a CVD method to produce a glass particle deposition body 25. The rod 30 is pulled out from the glass particle deposition body 25 to produce a cylindrical porous glass support body 21. A silica glass separation membrane layer 22 is formed on a surface of the porous glass support body 21 to manufacture hydrogen separation material 20. The method includes a densification step of densifying both ends in the axial direction of the porous glass support body 21.

Description

  The present invention relates to a fluid separation material for separating hydrogen and the like from a mixed gas containing hydrogen and the like produced by fuel reforming and the like, and a method for producing the same, and in particular, silica glass that selectively permeates hydrogen and the like. The present invention relates to a fluid separation material in which a separation membrane layer is formed on the surface of a porous glass support and a method for producing the same.

  In order to realize a hydrogen energy society, research and development on hydrogen production technology and hydrogen utilization infrastructure are underway. Fuel cells for automobiles, stationary fuel cells for home use, hydrogen stations, and large chemical plants in the future High-purity hydrogen used in Japan is expected to be in great demand in the future, and its production is required to have higher efficiency.

Currently, hydrogen is produced by steam reforming a hydrocarbon fuel at a temperature of about 700 ° C. (CH ₄ + H ₂ O → CO + 3H ₂ ), and then converting CO at a few hundred degrees (CO + H ₂ O → CO ₂ + H ₂ ) is widely used from the viewpoint of price competitiveness. Gas components obtained through these reactions include carbon dioxide, carbon monoxide, unreacted hydrocarbons and water in addition to hydrogen. In recent years, in polymer electrolyte fuel cell systems that have become popular in the home, the purity of hydrogen is not increased in order to reduce costs, and a mixed gas with a hydrogen concentration of about 60% is directly used as the fuel electrode of the fuel cell. However, the carbon monoxide poisoning the fuel electrode catalyst is oxidized to carbon dioxide (CO + 1 / 2O ₂ → CO ₂ ) before supply, and the concentration thereof is removed to less than 10 ppm. However, since a fuel cell using a mixed gas has lower power generation efficiency than a pure hydrogen fuel cell, there is a need for a technique for producing hydrogen with higher purity at a low cost in a space-saving manner. Further, in addition to the limitation of the CO concentration, it is necessary to supply 99.99% or more of hydrogen to the automobile fuel cell, and a technique for producing a large amount of inexpensive high-purity hydrogen is required.

  Examples of methods for extracting high-purity hydrogen from a mixed gas containing hydrogen include an absorption method, a cryogenic separation method, an adsorption method, and a membrane separation method. The feature of the membrane separation method is high efficiency and easy miniaturization. have. In addition, by configuring a membrane reactor in which a hydrogen separation membrane is inserted into a reaction vessel that performs steam reforming, hydrogen generated by the reforming reaction is continuously extracted from the reaction atmosphere, and the reforming reaction is performed even at a temperature of about 500 ° C. And CO shift reaction can be promoted at the same time, and high-purity hydrogen can be produced efficiently. Furthermore, an expensive noble metal catalyst such as platinum used for CO conversion is not required in the membrane reactor, and the cost can be reduced and the equipment can be downsized. The purity of the hydrogen gas that has passed through the hydrogen separation membrane depends on the performance of the hydrogen separation membrane, but even if CO removal or high purity is required depending on the application, the load on these steps should be reduced. Is possible.

  As described above, several hydrogen separation membranes have been proposed against the background of the advantage of the hydrogen production method using the hydrogen separation membrane. For example, Non-Patent Document 1 describes a hydrogen separation membrane in which a palladium alloy membrane is supported by a zirconia porous substrate. In this hydrogen separation membrane, hydrogen is dissolved as atoms in the palladium alloy, and is separated by a method of diffusing with the concentration gradient and allowing only pure hydrogen to permeate, so that high purity hydrogen can be obtained in principle. . Non-Patent Document 2 describes a hydrogen separation membrane in which a silica glass membrane is supported by an alumina porous substrate. This hydrogen separation membrane utilizes the fact that the silica glass membrane has pores with a size (0.3 nm) that allows only hydrogen molecules to pass through, and separates hydrogen by a molecular sieving function that selectively permeates hydrogen molecules. Is.

  In addition, as a hydrogen separation apparatus including a hydrogen separation cylinder having a hydrogen permeable membrane formed on the outside, a hydrogen separation cylinder in the shape of a test tube closed at one end, and a cylindrical shape in which an open end side of the hydrogen separation cylinder is inserted The thing provided with the attachment metal fitting is known (for example, refer to patent documents 1). In Patent Document 1, a mixed material in which nickel oxide, zirconia, and graphite powder are mixed is extruded to form a bottomed cylindrical tube, which is fired to produce a porous support tube, and a barrier that covers the periphery thereof. It describes that a hydrogen separation cylinder is manufactured by forming a hydrogen permeable membrane made of a metal thin film so as to cover the layer. The end of the open end side of the hydrogen separation cylinder is fitted to the mounting bracket together with the seal member, and is fixed by screwing the fixing bracket and the mounting bracket into the hydrogen separator.

JP 2009-234798 A

Summary of FY2008 Fuel Cell and Hydrogen Technology Development Symposium “Development of Highly Durable Membrane LP Gas Reformer” New Energy and Industrial Technology Development Organization “Development of High-Efficiency High-Temperature Hydrogen Separation Membrane” (Ex-post Evaluation) Minutes of Subcommittee Meeting (July 30, 2007)

  By the way, the present inventors made PCT / JP2010 / 072201 (Heisei 22) a hydrogen separation material having a silica glass membrane functioning as a hydrogen separation membrane and a porous body having a thermal expansion coefficient close to that of the silica glass membrane as its support. Filed on Dec. 10, 2000). According to this configuration, it is possible to realize a hydrogen separation material that is resistant to thermal shock, has good adhesion between the hydrogen separation membrane and the support, and has excellent hydrogen separation characteristics.

  However, a hydrogen filter tube composed of a porous silica glass support and a silica glass separation membrane seals the open end side with an airtight seal and uses it as a hydrogen separation material, but it must be tightened with the seal. Therefore, the holding part of the hydrogen filter tube needs to have mechanical strength, and if the strength is insufficient, it may be damaged. In addition, when a metal hydrogen separation cylinder is sealed to a metal fitting by screwing as in Patent Document 1, the difference in the coefficient of thermal expansion of the material is large, and a gap may be generated in the seal portion. .

  Further, in a hydrogen filter tube composed of a porous silica glass support and a silica glass separation membrane, the closed end side of the hydrogen filter tube has a convex curved surface. Holes are generated, and it is difficult to obtain a sufficient function as a hydrogen separation membrane.

  An object of the present invention is to provide a fluid separation material having a strength for sealing while being excellent in fluid separation characteristics such as hydrogen and a method for producing the same.

The method for producing a fluid separation material of the present invention capable of solving the above-mentioned problem is to produce a glass fine particle deposit by depositing glass fine particles around a rod by a CVD method,
Pull out the rod from the glass particulate deposit to produce a cylindrical porous glass support,
A method for producing a fluid separation material by forming a silica glass separation membrane layer on the surface of the porous glass support,
It includes a densification step of densifying both axial ends of the porous glass support.

  In the method for producing a fluid separation material of the present invention, it is preferable that after the densification step, a transparent quartz tube is joined to the open axial end of the porous glass support.

The fluid separation material of the present invention is a fluid separation material in which a silica glass separation membrane layer is formed on the surface of a cylindrical porous glass support made of a glass fine particle deposit formed by depositing glass fine particles,
Both ends in the axial direction of the porous glass support are densified.

  According to the present invention, since both end portions in the axial direction of the porous glass support are densified, the porosity of the porous glass is reduced and the density is increased or made transparent. This increases the strength of both ends. At the opening side end portion of the cylindrical porous glass support, sufficient strength for sealing is obtained. In addition, when the porous glass support has a bottomed cylindrical shape whose one end is closed, the closed end is densified and becomes a portion having a small porosity and no fluid permeability. It is possible to prevent the fluid separation function from being deteriorated due to permeation of fluid other than the fluid to be separated by the hole.

It is a longitudinal cross-sectional view which shows the example of the hydrogen separation material which is one Embodiment of this invention. It is a cross-sectional view of each part in the hydrogen separation material of FIG. It is a schematic diagram which shows (a) deposition process, (b) drawing process, (c) separation film formation process, and (d) densification process of both ends which are one Embodiment of the manufacturing method of this invention. It is a schematic diagram which shows in detail the densification process of both ends. It is a figure which shows the hydrogen separation module to which the hydrogen separation material of FIG. 1 is applied.

Hereinafter, an example of an embodiment of a fluid separation material and a manufacturing method thereof according to the present invention will be described with reference to the drawings.
In the present embodiment, a hydrogen separation material is described as an example of the fluid separation material. However, the present invention separates a gas or liquid other than hydrogen by changing the pore diameter of the silica glass separation membrane layer. It is also applicable. The shape of the fluid separation material can be an arbitrary shape such as a planar shape, but in order to increase the contact area with the fluid from the viewpoint of reaction efficiency, it is tubular in this embodiment.

(Hydrogen separation material)
1 and 2 show an embodiment of the hydrogen separation material. FIG. 1 is a longitudinal sectional view of a hydrogen separation material, and FIG. 2 is a transverse sectional view of each part. The hydrogen separation material 20 has a substantially cylindrical shape, and has a central hole 24 having a substantially circular cross section extending in the longitudinal direction at the center thereof. The hydrogen separation material 20 has a porous glass support 21 as a tube wall on the outer periphery of the center hole 24, and has a silica glass separation membrane layer 22 on the outer periphery. Further, a dense portion 38 made of densified silica glass is formed at one end of the hydrogen separation material 20 in the axial direction, and a dense tube portion 37 made of densified silica glass is formed at the other end. Is formed. The dense portion 38 and the dense cylinder portion 37 are preferably in a transparent state, but have a porosity (for example, 5% or less) at which the permeation rate of a gas other than hydrogen is sufficiently small even if not transparent. Just do it. The porosity varies depending on the required purity of hydrogen. The “porosity” can be calculated as the ratio of the air volume per unit volume.

  2A is a cross-sectional view of the dense tube portion 37 in the hydrogen separation material 20, and FIG. 2B is a porous glass support 21 and a silica glass separation membrane layer 22 in the hydrogen separation material 20. FIG. 2C is a cross-sectional view of the portion of the dense portion 38 in the hydrogen separation material 20. The dense cylindrical portion 37 has a central hole 24 continuous with the porous glass support 21, and the dense portion 38 is solid. The outer diameter T of the portion having the porous glass support 21 and the silica glass separation membrane layer 22 is 2 mm to 50 mm, the inner diameter (the diameter of the center hole 24) P is 1.6 mm to 48 mm, and the length is about 200 mm to 400 mm. It is. It is desirable that one end 24a of the center hole 24 is closed. Further, in order to increase the surface area of the hydrogen separation material 20, the outer diameter T and the inner diameter P may be periodically changed in the longitudinal direction, and the thickness may be partially changed to reinforce the mechanical strength. it can. Further, the length of the dense tube portion 37 is about 250 mm, for example, and the length of the dense portion 38 is about 30 mm, for example.

  In the hydrogen separation material 20, the silica glass separation membrane layer 22 is used as a hydrogen permeable membrane, whereby it is possible to suppress membrane deterioration due to hydrogen embrittlement and reaction with raw material impurities. The thickness of the silica glass separation membrane layer 22 is not particularly limited, but is preferably 0.01 μm to 50 μm, more preferably 0.02 μm to 10 μm, and 0.03 μm to 5 μm. More preferably. If the thickness is less than 0.01 μm, the hydrogen purity of the permeate gas becomes too low, and if it exceeds 50 μm, the hydrogen permeation rate becomes too low, and it may be difficult to obtain practically sufficient hydrogen separation performance.

  By using the support of the silica glass separation membrane layer 22 as the porous glass support 21, the thin film can be supported without interfering with hydrogen permeation through the silica glass separation membrane layer 22. The porosity of the porous glass support 21 is not particularly limited, but is preferably 20 to 70% from the balance of mechanical strength and gas permeability.

Moreover, the linear thermal expansion coefficient of the porous glass support 21 is 2 × 10 ⁻⁶ / K or less. When the linear thermal expansion coefficient exceeds 2 × 10 ⁻⁶ / K, the generated thermal stress increases, and the desired thermal shock resistance may not be obtained. The material for forming the porous glass support 21 is preferably a material whose linear thermal expansion coefficient approximates that of the silica glass separation membrane 22 from the viewpoint of thermal shock resistance, and more preferably porous silica glass.
The thickness of the porous glass support 21 is not particularly limited, but is preferably 0.2 mm to 5 mm, and preferably 0.5 mm to 3 mm from the balance of mechanical strength and gas permeability. Is more preferable.

  A porous protective film (not shown) may be provided on the outer periphery of the silica glass separation membrane layer 22. By providing the porous protective layer, the thin film can be protected without interfering with hydrogen permeation through the silica glass separation membrane layer 22. The porosity of the porous protective layer is not particularly limited, but is preferably 20 to 70% from the balance of mechanical strength and gas permeability.

Moreover, it is preferable that the linear thermal expansion coefficient of the porous protective layer is 2 × 10 ⁻⁶ / K or less like the porous glass support 21. The linear thermal expansion coefficient of the porous protective layer is preferably approximate to the linear thermal expansion coefficient of the porous glass support 21 and the silica glass separation membrane layer 22, and the porous protective layer is made of porous silica. Most preferred is glass.
The thickness of the porous protective layer is not particularly limited, but is preferably 0.01 mm to 1 mm from the balance of mechanical strength and gas permeability.

As described above, from the viewpoint of thermal shock resistance, the porous glass support 21 is preferably selected from those having a linear thermal expansion coefficient approximate to that of the silica glass separation membrane layer 22. In the hydrogen separation material 20 of the present embodiment, the material of the porous glass support 21 is preferably porous silica glass. In that case, the porous glass constituting the silica glass separation membrane layer 22 and the porous glass support 21 is used. A rare earth element, a group 4B element, Al, Ga, or a combination of two or more of these elements can be added to any of the porous silica glass. This is because by adjusting the components of the porous silica glass constituting the porous glass support 21 or the silica glass separation membrane layer 22, desired mechanical properties, water vapor resistance and the like can be obtained.
For example, when the hydrogen separation material 20 is used for steam reforming of hydrocarbon fuel, it necessarily comes into contact with steam at 500 ° C. or higher, and thus it is preferable to improve the steam resistance performance by introducing other components in this way. .

The porous silica glass constituting the porous glass support 21 can be manufactured by a manufacturing method such as a sooting method (CVD method) or an injection molding method. The formation method of the silica glass separation membrane layer 22 is not particularly limited. In addition to the sol-gel method and the CVD method, means for forming the surface by modifying the surface of the porous silica glass constituting the porous glass support 21 is used. be able to. “Surface modification” means that a portion that becomes a surface film, for example, the vicinity of the surface of the porous silica glass constituting the porous glass support 21 is densified to a certain degree in order to produce a hydrogen permeable membrane portion. This means to form a dense silica glass layer. One method is by heating. Specifically, for example, a method of irradiating a CO ₂ laser, a plasma arc, an oxyhydrogen burner or the like singly or in combination.

As described above, the silica glass separation membrane layer 22 can be manufactured also by the sol-gel method or the CVD method. The bonding strength between the membrane and the support can be increased as compared with the manufacturing method in which the layer 22 is manufactured separately and laminated, and the thickness of the silica glass separation membrane layer 22 and the size of the holes can be simplified depending on the degree of densification. Can be controlled. The degree of densification of the silica glass separation membrane layer 22 is set by the molecular size of the fluid to be separated. From the viewpoint of hydrogen permeation, it is desirable that the silica glass separation membrane layer 22 be densified so that the pore diameter is about 0.3 nm.
The porous protective layer can be formed by depositing porous silica glass on the outer periphery of the silica glass separation membrane layer 12 by a sooting method (CVD method).

  As described above, the hydrogen separation material 20 has the dense portion 38 and the dense cylinder portion 37 by densifying both axial ends of the porous glass support 21. Thereby, both ends of the hydrogen separation material 20 are increased in strength. For example, the dense cylindrical portion 37 can provide sufficient strength for sealing when used in a hydrogen separation module. Further, in the dense portion 38 whose end portion is closed, the porosity is reduced to become a portion having no hydrogen permeability, and the generation of pinholes is suppressed. Can be prevented from penetrating and deteriorating the hydrogen separation function.

  Moreover, both ends of the hydrogen separation material 20 may be open. That is, you may make it have the dense cylinder part 37 at the axial direction both ends of the porous glass support body 21 which both ends opened, respectively.

(Method for producing hydrogen separation material)
Hereinafter, an embodiment of the method for producing the hydrogen separation material will be described with reference to the drawings.
(1) Porous glass support formation process As a suitable example of the manufacturing method in the case of the tubular hydrogen separation material 20 and the porous glass support 21 is porous silica glass, glass fine particles are placed around the rod. An example is a method in which a glass fine particle deposit is formed by deposition (deposition step) and then the rod is pulled out (drawing step). An embodiment of the method will be described below with reference to FIG.

  FIG. 3A is a diagram illustrating a deposition process according to the present embodiment, and FIG. 3B is a diagram illustrating a drawing process according to the present embodiment. In FIG. 3 (a), the rod 30 is arranged vertically with the tip portion facing down. Moreover, it is good also as a form arrange | positioned horizontally. As a material for the rod 30, alumina, glass, refractory ceramics, carbon, or the like can be used. After the rod 30 is fixed, the rod 30 is rotated about the central axis. Then, silica glass fine particles are deposited on the outer periphery of the rod 30 by a burner 31 disposed on the side of the rod 30 by a sooting method (CVD method). The silica glass fine particles can be added with rare earth elements, group 4B elements, Al, Ga, or a combination of two or more of these elements depending on the desired mechanical properties and water vapor resistance. That is, according to this manufacturing method, the components can be easily adjusted.

  When depositing the glass fine particles, the burner 31 is traversed in the axial direction of the rod 30, or the burner 31 is fixed and the rod 30 is traversed in the axial direction. The type of feedstock and gas supply amount to the burner 31 can be varied for each number of traverses. Thereby, the silica glass fine particles deposited on the outer periphery of the rod 30 have a predetermined bulk density and composition distribution in the radial direction. Further, by depositing silica glass fine particles on the tip of the rod 30, a tubular glass fine particle deposit 25 having a closed tip is produced.

  The glass fine particle deposit 25 may heat-sinter the silica glass fine particles so that the porosity thereof is in the range of 20 to 70% after the silica glass fine particles are deposited. The porosity may be controlled while adjusting the temperature. The temperature for heating and sintering after deposition is not particularly limited, but is preferably 1000 ° C to 1400 ° C. If it is less than 1000 ° C., sintering may not proceed sufficiently, and if it exceeds 1400 ° C., the porosity may be too small. Also, when the porosity is adjusted by the deposition temperature, the temperature is not particularly limited, but is preferably about 1000 ° C. to 1700 ° C., for example. If the deposition temperature is too low, the sintering of the silica glass fine particles may not proceed sufficiently, and if it exceeds 1700 ° C., the porosity may be too small. Moreover, it is preferable that the deposition temperature of the silica glass fine particles in the outermost layer of the glass fine particle deposit 25 is kept high. When the deposition temperature in the outermost layer is less than 1400 ° C., the sintering of the silica glass fine particles does not proceed sufficiently, and the desired impact resistance may not be obtained in the outermost layer.

FIG. 3B shows a drawing process after the deposition process. In FIG. 3B, the rod 30 is pulled out from the glass particulate deposit 25. The central hole 24 formed by drawing does not penetrate, the lower end side (tip end side) 24a is closed, and only the upper end side is opened (see FIG. 2). In order to facilitate drawing, it is preferable to apply carbon, nitride, or the like to the surface of the rod 30 in advance. Similarly, from the viewpoint of facilitating pulling, the rod 30 preferably has a tapered shape, and for example, the outer diameter gradient can be set to 0.2 to 2.0 mm / 1000 mm. Furthermore, the rod 30 preferably has a thermal expansion coefficient of 5 × 10 ⁻⁶ / K or less. This is because if the thermal expansion coefficient of the rod 30 is high, the rod 30 may expand and contract each time the burner 31 approaches during the deposition process, and the glass particulate deposit 25 may be damaged. Moreover, the rod 30 itself can be prevented from being damaged by thermal shock by setting the coefficient of thermal expansion within the above range. Furthermore, the rod 30 is preferably a rod made of a non-oxide such as silicon nitride having a low affinity with glass, for example.

(2) Silica glass separation membrane layer forming step After the porous glass support 21 composed of the glass fine particle deposit 25 is formed, the porous glass support 21 is formed by a sol-gel method, a CVD method, a method for modifying the surface of porous silica glass, or the like. A silica glass separation membrane layer 22 is formed on the surface of the glass support 21. FIG.3 (c) is a figure which shows the silica glass separation membrane layer formation process which concerns on this embodiment. Here, a method will be described in which the surface of the porous glass support 21 is surface-modified by a surface treatment device to form a silica glass separation membrane layer 22 on the porous glass support 21.

The porous glass support 21 obtained in the porous glass support forming step is densified on the surface by the surface treatment device 32, thereby being surface-modified as a dense silica glass separation membrane layer 22. The The surface treatment device 32 may be any device that can irradiate high-temperature energy rays, for example, and a CO ₂ laser, a plasma arc, an oxyhydrogen burner, or the like can be used alone or in combination. The surface of the porous glass support 21 is thus modified to form the hydrogen separation material 20 having the porous support 21 and the silica glass separation membrane layer 22.

  The degree of surface modification of the silica glass separation membrane layer 22 is not particularly limited as long as the silica glass separation membrane layer 22 functions as a hydrogen permeable membrane. The thickness is preferably 0.01 μm to 50 μm, more preferably 0.02 μm to 10 μm, and still more preferably 0.03 μm to 5 μm. Moreover, it is preferable that the silica glass separation membrane layer 22 has a hole having a diameter of about 0.3 nm so as to transmit only hydrogen molecules.

(3) Densification Step of Both Ends Subsequently, as shown in FIG. 3 (d), both ends of the porous glass support 21 on which the silica glass separation membrane layer 22 is formed are densified regions (dense Part 38, dense cylinder part 37) is formed (dense step of both ends).

  FIG. 4 is a schematic diagram showing a densification process at both ends. As shown in FIG. 4, the densification process of both ends includes (i) at least the dense cylinder portion 37 by densifying the end region on the opening side of the porous glass support 21 by heat shrinking with a burner 34. A step of forming a part (see FIG. 4A), and (ii) a cylindrical transparent quartz tube 39 is heated and bonded to the heat-shrinked region of the porous glass support 21 by a burner 34 to form a dense cylinder. A step of forming the portion 37 (see FIG. 4B), and (iii) a dense portion 38 is formed by heating and shrinking the end region on the closed side of the porous glass support 21 with a burner 34. (See FIG. 4C). In the step (ii) of forming the dense cylindrical portion 37, the cylindrical transparent quartz tube 39 is joined so that the center hole thereof is airtightly connected to the center hole of the porous glass support 21. FIG. 4D is a schematic view of the porous glass support 21 provided with the dense cylindrical portion 37 and the dense portion 38, and corresponds to the state of FIG.

  In the step (i), the length of the dense cylindrical portion 37 to be formed is, for example, 30 mm or less. In the step (ii), the length of the transparent quartz tube 39 to be joined is about 220 mm. The transparent quartz tube 39 has a length and a diameter that match the dimensions attached to the hydrogen separation module described later. Therefore, the transparent quartz tube 39 may have an outer diameter and an inner diameter that change in the longitudinal direction.

  In the above step (iii), the end region on the closing side of the porous glass support 21 is densified, so that there is a pinhole in the silica glass separation membrane layer 22 in that region before densification. However, the pinhole is eliminated by densification. In the dense portion 38, the porosity becomes small due to the densification, and the portion does not have hydrogen permeability, and fluid other than hydrogen does not permeate. That is, it is possible to prevent the hydrogen separation function from being deteriorated due to permeation of fluid other than hydrogen from the closed end of the hydrogen separation material 20.

  The porous protective layer may be formed on the outer periphery of the silica glass separation membrane layer 22 after the step (iii). By forming the porous protective layer, the thin film can be protected without interfering with hydrogen permeation through the silica glass separation membrane layer 22.

  In the above manufacturing example, the transparent quartz tube 39 is joined in the densification process at both ends. However, the transparent quartz tube 39 may be joined. In that case, in the step of heat-shrinking the end region on the opening side of the porous glass support 21 shown in FIG. 4A by the burner 34, the length of the region to be heat-shrinked is increased. That's fine. Accordingly, the dense cylindrical portion 37 having a sufficient length for sealing when used in the hydrogen separation module can be formed without joining the transparent quartz tube 39. However, since it is necessary to densify the long section, it is advantageous to join the transparent quartz tube 39 from the viewpoint of working time and manufacturing cost.

  Further, when the hydrogen separation material 20 having both ends opened is manufactured, the dense cylindrical portion 37 may be formed by heating and shrinking both axial ends of the porous glass support 21 having both ends opened. Thereby, it can respond also to the case where both ends are sealed when used in a hydrogen separation module. A transparent quartz tube 39 may be further joined to the dense cylindrical portion 37 that has been heat-shrinked.

  In the above production example, the silica glass separation membrane layer 22 is formed by surface densification of the porous glass support 21 made of the glass fine particle deposit 25. However, the step of forming the silica glass separation membrane layer is performed by a sol-gel method. Or by the CVD method. In this case, it is desirable to perform a porous glass support forming step (a step of depositing glass fine particles around the rod and a step of pulling out the rod), a densifying step at both ends, and a silica glass separation membrane layer forming step in this order.

(Hydrogen separation module)
Next, an example of a hydrogen separation module to which the hydrogen separation material 20 is applied will be described with reference to FIG. A hydrogen separation module 40 shown in FIG. 5 includes a hydrogen separation material 20 and a steam reforming catalyst 41 in a reaction vessel 42. The reaction vessel 42 has an introduction port 43 for introducing the raw material gas 50 into the reaction vessel 42, an exhaust port 44 for discharging the exhaust gas 51 from the reaction vessel 42, and an installation for installing the hydrogen separation material 20 in the reaction vessel 42. And a mouth 45. The steam reforming catalyst 41 is packed around the hydrogen separation material 20 in the reaction vessel 42.

  The raw material gas 50 is obtained by burning fuel such as city gas, propane gas, kerosene, petroleum, biomethanol, natural gas, methane hydrate and the like. After being introduced into the reaction vessel 42, the source gas 50 is heated at about 500 ° C. and reformed by the steam reforming catalyst 41 (for example, a Ru-based catalyst) to generate hydrogen gas. During the reforming reaction, the generated hydrogen gas is selectively drawn out by the tubular hydrogen separation material 20, permeated to the inner central hole 24, and taken out of the reaction vessel 42. For this reason, hydrogen production is promoted in a chemical equilibrium, the reaction temperature can be lowered, and a CO shift reaction occurs at the same time, so that a CO shift catalyst is theoretically unnecessary.

  In such a hydrogen separation module 40, the installation port 45 is sealed between the hydrogen separation material 20 and the end of the hydrogen separation material 20 on the opening side, that is, the dense tube portion 37 is fixed. Since the dense cylindrical portion 37 is made of porous silica glass as described above, it has mechanical strength for hermetically sealing at the installation port 45. In addition, since the end of the hydrogen separation material 20 on the closing side is the dense portion 38, no gas other than hydrogen is taken into the hydrogen separation material 20 from the pinhole.

  In the hydrogen separation module, when a hydrogen separation material having both ends opened is used, the raw material gas is introduced into the inner space from one end side of the hydrogen separation material, and the exhaust gas is discharged from the other end side. Hydrogen can also be removed around the separation material.

  Moreover, it can also be set as the hydrogen production apparatus further provided with the CO removal module which has a CO methanation catalyst etc. using said hydrogen separation module. The hydrogen production apparatus can be used for household stationary fuel cells. In addition, by providing a hydrogen purification module to which a pressure swing adsorption (PSA) method is applied, a hydrogen production apparatus used for an automobile fuel cell can be obtained.

20: Hydrogen separation material, 21: Porous glass support, 22: Silica glass separation membrane layer, 24: Center hole, 25: Glass fine particle deposit, 30: Rod, 31, 34: Burner, 32: Surface treatment device, 37: Dense cylinder part, 38: Dense part, 39: Transparent quartz tube

Claims (3)

A glass fine particle deposit is produced by depositing glass fine particles around the rod by CVD,
Pull out the rod from the glass particulate deposit to produce a cylindrical porous glass support,
A method for producing a fluid separation material by forming a silica glass separation membrane layer on the surface of the porous glass support,
A method for producing a fluid separation material, comprising a densification step of densifying both axial ends of the porous glass support. It is a manufacturing method of the fluid separation material according to claim 1,
After the densification step, a transparent quartz tube is joined to the opened axial end portion of the porous glass support, and the method for producing a fluid separation material. A fluid separation material in which a silica glass separation membrane layer is formed on the surface of a cylindrical porous glass support made of a glass fine particle deposit formed by depositing glass fine particles,
A fluid separation material, wherein both ends of the porous glass support in the axial direction are densified.

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