JPH07124453A - Hydrogen separation membrane and its production - Google Patents

Abstract

PURPOSE:To easily obtain a hydrogen separation membrane excellent in heat resistance and mechanical strength, prevented from the deposition of carbon from a gas to be treated and improved in workability by supporting a palladium alloy membrance from the both side with a metallic supporting body and metallic plate on which many narrow pores having specific pore diameter are drilled. CONSTITUTION:The hydrogen separation membrane is formed by sticking the palladium alloy membrance 12 having 1-50mum film thickness on one face 11a of the metallic supporting body 11 on which many narrow pores (h) 10-500mum in pore diameter are drilled by etching. The metallic plate 13 on which many narrow pores 1 are drilled by etching on the surface of the palladium alloy membrane 12 side is laminated on the palladium alloy membrane 12. If necessary, a metallic thin film of gold, silver, platinum, palladium, rhodium, copper or an alloy thereof is stuck by electroplating method to the metallic plate 13 with many drilled narrow pores.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrogen separation membrane for diffusing and separating hydrogen in a hydrogen-containing gas and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, hydrogen gas has been used as natural gas, LPG,
It is produced by a steam reforming method using hydrocarbons such as naphtha or methanol as a raw material, and is also produced from offgas for petroleum refining. As a method for purifying and recovering hydrogen from the hydrogen-containing gas produced by the above method, a PSA method (Pressure Swing) using an adsorbent is used.
Absorption) and other methods for separating and removing impurities, and methods for diffusively separating hydrogen with an organic or inorganic hydrogen separation membrane. Among these methods, the membrane separation method is energy-saving, separation efficiency, and simple device configuration and operation. It is attracting attention from the viewpoint of ease of use.

Hydrogen separation membranes used in the membrane separation method include organic polymer membranes such as polyimide and polysulfone, inorganic porous membranes such as porous glass and porous ceramics,
And palladium or palladium alloy film.
Among them, the organic polymer membrane has a problem in heat resistance and reduction in separation efficiency at high temperature, and also has a defect that the separation efficiency is low even in the inorganic porous membrane, and further in the palladium or palladium alloy membrane, there is also heat resistance. Moreover, although hydrogen of extremely high purity can be obtained, there are problems such as mechanical strength and difficulty of thin film manufacturing technology.

As a hydrogen separation membrane in which the mechanical strength of the palladium or palladium alloy membrane is increased, Japanese Patent Laid-Open No. 62-1 / 1987 has been proposed.
21616, JP-A-62-273030,
Japanese Patent Laid-Open No. 63-171617 discloses a porous glass,
Membranes in which a palladium or palladium alloy membrane is deposited on the surface of an inorganic porous support such as porous ceramics or porous aluminum oxide are disclosed, and in these publications, a method for producing the hydrogen separation membrane is disclosed. Is also described. Furthermore, in Japanese Patent Application No. 4-131420, by forming a palladium alloy film on one surface of a metal support having a large number of pores, heat resistance, mechanical strength, and separation performance are excellent. It has been proposed that a hydrogen separation membrane can be obtained.

In the method for producing a hydrogen separation membrane described in the above publication, according to the method disclosed in JP-A-62-121616, a palladium or palladium alloy membrane is formed on the surface of an inorganic porous support having a thickness of about 1 mm. Is deposited by a vapor phase chemical reaction or a vacuum deposition method, but it has a drawback that the device is complicated and requires an advanced manufacturing technique, and that it takes time to manufacture a thick film. Further, in the method disclosed in Japanese Patent Laid-Open No. 62-273030, after the surface of the inorganic porous material is chemically activated, a palladium-based film is deposited by a chemical plating method. And there is a drawback that it is time-consuming. Further, in the method disclosed in Japanese Patent Laid-Open No. 63-171617, for example, after anodizing the metallic aluminum,
Metallic aluminum is dissolved and removed by etching method to a thickness of 5
A porous aluminum oxide film having a thickness of about 0 μm is manufactured, and palladium or a palladium alloy is deposited on the film by a sputtering method, and then palladium is further supported by an aqueous solution of a palladium salt, which is very time-consuming and requires a high degree of performance. There are drawbacks that require membrane technology. Furthermore, Japanese Patent Application No. 4-131
The hydrogen separation membrane proposed in No. 420 has excellent heat resistance, mechanical strength, and separation performance, but since the palladium alloy membrane is exposed, the surface of the membrane is easily scratched and peeling of the membrane occurs. May occur.

[0006]

The present invention has been made against the background of the above-mentioned problems of the prior art. The palladium alloy film is supported from both sides by a metal support and a metal plate in which pores having a predetermined pore diameter are perforated. Therefore, the heat resistance and mechanical strength are further excellent, high-purity hydrogen can be recovered, and the separation performance is excellent even at high temperatures, and the precipitation of carbon due to the gas to be treated can be prevented. An object of the present invention is to provide a hydrogen separation membrane capable of easily manufacturing a hydrogen separation membrane having excellent workability in a short time with a small labor and a manufacturing method thereof.

[0007]

The present invention has a hole diameter of 10 to 5
A palladium alloy film (hereinafter also referred to as "palladium alloy film") having a film thickness of 1 to 50 μm and made of palladium and another metal is adhered and formed on one surface of a metal support in which a large number of 00 μm pores are formed by etching. Further, on the surface of the palladium alloy film, a large number of pores are preliminarily formed on both surfaces by etching, and if necessary, gold, silver,
A hydrogen separation membrane, comprising a stack of metal plates coated with thin films of platinum, palladium, rhodium, copper or alloys thereof (hereinafter sometimes referred to as "metal thin film").

Further, the present invention is a method for producing the hydrogen separation membrane, which comprises the following steps. (1) A first step of alternately laminating thin films of palladium and another metal on one surface of a metal support by electroplating. (2) A second step of forming a large number of pores on the other surface of the metal support obtained in the first step by an etching method. (3) A third step in which the palladium of the metal support obtained in the second step and another metal thin film layer are heat treated at 500 to 900 ° C. to form a palladium alloy. (4) A fourth step of forming a large number of pores on both surfaces of the metal plate by an etching method. (5) If necessary, add gold to the metal plate obtained in the fourth step,
A fifth step of forming a thin film of silver, platinum, palladium, rhodium, copper or an alloy thereof by electroplating. (6) A sixth step of laminating the metal plate obtained in the fourth step or the fifth step on the surface of the palladium alloy film of the metal support obtained in the third step.

An example of the hydrogen separation membrane of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view showing a part of the hydrogen separation membrane manufacturing process, and FIG. 1 (A) is an enlarged cross-sectional configuration diagram for explaining a state in which a palladium alloy membrane is deposited / formed on one surface of a metal support. 1 (B) is an enlarged cross-sectional configuration diagram for explaining a state in which a large number of pores are perforated by etching the other surface of the metal support of FIG. 1 (A), FIG. 1 (C)
FIG. 3 is an enlarged cross-sectional configuration diagram of a hydrogen separation membrane of the present invention in which a metal plate is subjected to double-sided etching treatment, and then the surface of which is plated with silver or the like is deposited / formed on the surface side of a palladium alloy membrane.

The hydrogen separation membrane 10 of the present invention has a pore size of 10 to 10.
One side 1 of the metal support 11 in which a large number of pores h of 500 μm, preferably 50 to 200 μm, are formed by etching.
The palladium alloy film 12 having a film thickness of 1 to 50 μm, preferably 5 to 30 μm is deposited and formed on the la 1a (see FIGS. 1A to 1B). The palladium alloy film 12 is formed by laminating a metal plate 13 on the surface side of the palladium alloy film 12 in which a large number of pores I having a pore diameter of 20 to 1,000 μm, preferably 100 to 400 μm are formed by etching. [See FIG. 1C].

Here, as the material of the metal support 11,
Stainless steel, nickel, copper alloy, nickel base alloy, iron −
Examples include metals such as nickel alloys. Hydrogen separation membrane 10
By adopting the metal support 11 as the support of
Even if the hydrogen separation treatment is performed at a temperature of 200 ° C. or higher, the hydrogen separation membrane 10 and the mounting member (frame, etc., not shown) can be connected by means such as welding, so that the sealing property does not deteriorate. When an inorganic material such as ceramics is used in place of the metal support 11, there is a problem that electroless plating with a slow film formation rate is necessary because electroplating cannot be directly performed. The pore diameter d of the large number of pores h perforated in the metal support 11 is 10 to 500 μm, preferably 50 to 200 μm. If it is less than 10 μm, the flow resistance becomes large, while if it exceeds 500 μm, it is an adherend film. The palladium alloy film 12 is depressed and pinholes are easily generated. The perforation density of the pores h is preferably about 150 to 3,000 per cm ² .

The thickness of the metal support 11 is usually 10-5.
00 μm, preferably about 50 to 200 μm, and 1
If it is less than 0 μm, the mechanical strength as a support is weak and not practical, while if it exceeds 500 μm, it is necessary to etch perforations having a large pore size, which is not preferable. The shape of the metal support 11 may be tubular as well as plate-like as shown in FIG. 1, and any shape may be adopted depending on the purpose.

On the other hand, the palladium alloy film 12 is a thin film of an alloy containing palladium as a main component, and is composed of palladium, a Group VIII element (for example, cobalt and nickel) other than palladium, and an IB group (for example, copper). Silver, gold), and an alloy with at least one other metal selected from the group IIIB (eg, yttrium), preferably an alloy of palladium and silver. The content of metals other than palladium in the palladium alloy film 12 is 1
˜50% by weight, preferably 10 to 30% by weight. The main purpose of alloying palladium is to prevent hydrogen embrittlement of palladium and to improve the separation efficiency at high temperatures. If the content of other metals than palladium is less than 1% by weight, the prevention of hydrogen embrittlement of palladium and high temperature The effect of improving the separation efficiency decreases,
On the other hand, if it exceeds 50% by weight, the hydrogen permeation rate becomes too slow, which is not practical.

The total thickness of the palladium alloy film 12 is 1 to 50.
μm, preferably 5 to 30 μm. If the total thickness of the palladium alloy film 12 is less than 1 μm, pinholes are likely to occur in the alloy film 12, normal deposition becomes difficult, and the purity of the separated hydrogen decreases, while if it exceeds 50 μm, the hydrogen The transmission speed is too slow to be practical.

Examples of the material of the metal plate 13 include metals such as stainless steel, nickel, copper alloys, nickel-base alloys and iron-nickel alloys. Palladium alloy film 12
In addition, by laminating the metal plate 13, the peeling of the palladium alloy membrane 12 can be prevented, the durability as the hydrogen separation membrane can be improved, and the membrane strength can be increased. For etching the metal plate 13, the same film mask as that used for etching the metal support 11 is used, and after exposure, etching is performed from both sides. The pores I perforated by etching are perforated at the same pitch as the metal support 11, and by performing etching from both sides,
The hole diameter is larger than the hole diameter formed in the metal support 11. The thickness of the metal plate 13 is usually 10 to 500 μm, preferably 50 to 200 μm.

If necessary, a metal thin film of gold, silver, platinum, palladium, rhodium, copper or their alloys is electroplated on a metal plate 13 having a large number of pores to a thickness of 0.01 to 0.01. 1 μm, preferably 0.05-0.1 μm
Apply a degree of plating. This makes it possible to obtain stable performance in the separation of hydrogen from a gas produced by decomposing or reforming hydrocarbons, alcohols, etc. in the gas to be treated without depositing carbon. The metal plate 13 made of stainless steel or the like is used when the gas to be treated for hydrogen separation does not contain a carbon compound such as hydrocarbon, carbon dioxide, or carbon monoxide, or under a relatively low temperature of about 450 ° C. or lower. As it is, plating of the metal thin film is unnecessary.

Next, the method for producing the hydrogen separation membrane of the present invention will be described.
This will be described with reference to FIG. First, in the first step, thin films of palladium and another metal are alternately laminated on one surface 11a of the metal support 11 by electroplating.

That is, for example, first, palladium and another metal are alternately laminated and deposited by electroplating on one surface 11a of the electroplated metal support 11.
In this electroplating method, a commonly used electroplating apparatus is used. When plating a thin film of palladium, an aqueous solution in which a palladium salt and an electrolyte are dissolved is used as the electroplating solution, and one side of the metal support 11 is connected to the minus side in the electrolytic bath filled with the electroplating solution. 1
It is deposited and formed by immersing 1a and a platinum plate connected to the positive side and energizing a DC power supply. Examples of this electroplating solution include, for example, the following, but are not limited to this composition, and may be a composition in which a palladium film or another metal film is laminated and deposited by an electroplating method. There is no particular limitation.

For Pd film; [Pd (NH ₃ ) ₄ ] Cl ₂ .2H ₂ O; 30 g / l,
NH ₄ Cl; 60 g / l, for Ag film; AgCN; 36 g / l, KCN; 60 g / l, K ₂ CO
₃ ; 15 g / l for Ni film; NiSO ₄ ; 240 g / l, NiCl ₂ ; 45 g / l,
H ₃ BO ₃ ; 30 g / l

For Co film; CoSO ₄ ; 300 g / l, NH ₄ Cl; 20 g / l,
H ₃ BO ₃ ; 15 g / l, for Cu film; CuSO ₄ .5H ₂ O; 250 g / l, H ₂ SO ₄ ; 7
5 g / l

The current density according to this electroplating method varies depending on the properties of the electroplating solution, but is 0.1-3 A / d.
m ² . Further, the total thickness of the thin films (palladium film and other metal film) can be set to the above-mentioned predetermined film thickness by making the electroplating time variable.

The palladium alloy film 12 is formed by forming a palladium thin film by, for example, an electroless plating method in addition to alternately laminating palladium and another metal, and laminating a thin film of an alloyed metal on the thin film. It may be deposited or may be deposited in the reverse process, and it is also possible to use the impregnation method, adsorption method, ion exchange method, vacuum deposition method (PVD), vapor phase chemical reaction method (CVD), etc. Is.

Next, in the second step, fine holes are formed in the other surface 11b of the metal support 11 obtained in the first step by an etching method. In this case, as a method of etching the other surface 11b of the metal support 11, for example, a negative resist (not shown) is applied to the one surface 11b by dip pulling up, and after baking, a pattern corresponding to the pores h is formed. It is carried out by irradiating light such as ultraviolet rays through a mask (not shown), post-baking after development, and further etching to remove the remaining resist film.

That is, prior to applying the resist,
In order to ensure the adhesiveness of the resist to the metal support 11, as a pretreatment, for example, alkali washing with 10% by weight sodium hydroxide aqueous solution at 70 ° C., water washing, neutralization, water washing, and drying are performed to remove the resist coating surface. Clean it. The resist to be used can be a casein type, a water-soluble type such as PVA type, or a negative type resist of an acrylic polymer-based solvent-soluble type,
In the present invention, a negative type acrylic polymer [PMER-N40DP, manufactured by Tokyo Ohka Kogyo Co., Ltd.] was used. As a method for applying the resist to the cleaned metal support 11 described above, a roll coating method, a spin coating method, a dip lifting coating method or the like is applied, and the dip lifting method is preferable.

The thickness to be applied is determined by the resist viscosity and pulling speed, but from the viewpoint of resolution during exposure,
The thickness is preferably 15 μm or less, and more preferably 3 μm or more from the viewpoint of acid resistance during etching and maintaining the strength of the resist film. Therefore, the pulling speed may be determined so that the dry film thickness is in the range of 3 to 15 μm. The resist to be applied is, for example, a solid content concentration of 30% by weight mainly composed of an acrylic polymer and a solvent content 70 mainly composed of toluene.
In the case of using the one containing wt%, it is dried in hot air at 70 ° C. for 10 minutes or more prior to the exposure, and the solvent component is dried and removed. In this way, a film mask on which the pattern of the preformed pores is imaged is brought into close contact with the support side of the resist film coated on the metal support 11, and ultraviolet rays having a wavelength of about 375 nm generated by an ultra-high pressure mercury lamp are attached. For 60 to 70 seconds (irradiation amount = 300 to 350 m
J) Irradiate.

In the fine hole pattern portion image-formed on the resist surface on the metal support 11 side in the exposure step, the resist is dissolved and removed only in the etching perforation portion (unexposed portion) in the next development step, and the metal surface is exposed. To be done. The conditions of this development are, for example, at 25 ± 2.5 ° C. with an alkaline special chemical solution [N-A5 manufactured by Tokyo Ohka Kogyo Co., Ltd.].
The resist film on which a pattern of holes to be opened is formed by this developing step is post-baked prior to the etching step in order to further improve the acid resistance strength, coating adhesion and coating strength of the film. The heat source of this post bake is
Either hot air or far-ultraviolet radiation may be used, but the temperature is 100 to 120 ° C. for 15 to 30 minutes. 10
If it is lower than 0 ° C, thermal polymerization is insufficient and sufficient coating performance cannot be obtained, while if it exceeds 120 ° C, the film becomes brittle.

After that, the etching process is started, but the etching solution is usually a second chloride of 42 to 47 ° Be (Baume).
The iron solution is sprayed onto the surface of the object. In this case, from the viewpoint of mass productivity, it is preferable to spray by vertical spraying by a horizontal transfer method. The liquid temperature is between 45 and 65 ° C. The control of the etching rate is determined by the transport speed. In order to stabilize the etching conditions and control the accuracy, water and hydrochloric acid are used, and the specific gravity and pH value are also controlled. By this etching, the metal support 11 perforated from one side is washed thoroughly with water after washing the etching solution with water and peeling off the residue of the resist film used for masking from the surface.
Become a product. This stripping solution is usually prepared by immersing an aqueous solution of 5 to 10% by weight of sodium hydroxide in a solution heated to 50 to 70 ° C. to remove the resist film by swelling and stripping.

By this second step, as shown in FIG. 1B, a large number of fine holes h, which are through holes, are punched from the other one surface 11b side of the metal support 11. In addition, in FIG. 1B, the symbol w indicates the palladium alloy film 12 and the metal support 1.
1 is the shortest contact distance, which is usually 100-
It is about 1,000 μm. In this etching step, the palladium obtained in the first step and another metal thin film layer may be heat-treated and alloyed, and then the etching treatment may be performed.

Further, in the third step, the palladium of the metal support obtained in the second step and another metal thin film layer are mixed with each other.
It heat-processes at 0-900 degreeC and alloys. The thin film deposited in the first step is a film in which palladium and another metal are laminated. To form an alloyed palladium alloy film, the second film is used.
The hydrogen separation membrane 10 obtained in the step is heat-treated in an electric furnace or the like to form metals by mutual diffusion. The heat treatment temperature is 500 to 900 ° C., preferably 6
When the temperature is from 00 to 800 ° C. and the temperature is lower than 500 ° C., mutual diffusion of metals does not occur. On the other hand, when the temperature is higher than 900 ° C., diffusion mixing from the metal support 11 is too large to be ignored,
In addition, the plating layer may melt during the heat treatment to form voids, which may impair the function of the film, which is not preferable. The heat treatment time is preferably 0.1 to 10 hours. In the alloying of the third step, the palladium obtained in the first step and the other metal thin film layer may be first heat-treated for alloying and then etched.

In the fourth step, a metal plate 13 prepared separately is used.
A large number of pores are perforated on both surfaces by the etching method. It is the same as the second step except that the etching solution is sprayed from both sides in the etching step.

In the fifth step, the surface of the metal plate obtained in the fourth step is further subjected to gold plating by electroplating, if necessary.
A thin metal film made of silver, platinum, palladium, rhodium, copper or an alloy thereof is deposited. Examples of this electroplating solution include, for example, the following, but are not limited to this composition and are not particularly limited as long as they are compositions to which these metals are deposited.

For Au; Au (CN) ₂ ; 6-18 g / l, KCN; 30 g /
1, K ₂ CO ₃ ; 30 g / l, dibasic potassium phosphate; 3
0 g / l for Pd; [Pd (NH ₃ ) ₄ ] Cl ₂ .2H ₂ O; 30 g / l,
NH ₄ Cl; 60 g / l,

For Ag; AgCN; 36 g / l, KCN; 60 g / l, K ₂ CO
₃ ; 15 g / l for Cu; CuSO ₄ .5H ₂ O; 250 g / l, H ₂ SO ₄ ; 7
For 5g / l Rh; Metal rhodium (as sulfate or phosphate) 1-4g
/ L, phosphoric acid; 40-80 g / l

The current density according to this electroplating method varies depending on the properties of the electroplating solution, but is 0.1-3 A / d.
m ² . Further, the total thickness of the metal thin film can be set to the above-mentioned predetermined thickness by changing the electroplating time.

In the sixth step, the palladium alloy film 12 on the metal support 11 obtained in the third step is provided with the metal plate 13 obtained in the fourth step or the fifth step, as shown in FIG. 1 (C). Laminate by a method such as laser welding. At this time, the pores I of the metal support 11 are positioned at least at substantially the same centers as the pores h of the metal plate 13 so that the hydrogen diffused through the metal plate 13 into the palladium alloy film 12 can be easily transmitted. It is necessary to stack so that

Palladium alloy film 12 on metal support 11
2 shows an example of stacking the metal plates 13 obtained in the fourth step or the fifth step. First, as shown in FIG. 2A, the palladium alloy film 12 on the metal support 11 is welded to a frame 14 such as a stainless material by laser welding or the like. On the other hand, the metal plate 13 which has been etched on both sides is provided on a frame 14 'made of stainless steel or the like as shown in FIG. 2 (A).
Weld in the same manner as. As shown in FIG. 2 (C), these are welded at the portions of the frames 14 and 14 'to form the hydrogen separation membrane 1
0 is formed.

Next, an example of the hydrogen separation method using the hydrogen separation membrane 10 will be described with reference to FIG. Here, FIG.
FIG. 3 is a process schematic view of a hydrogen separation method using the hydrogen separation membrane 10 of the present invention. In FIG. 3, the separator S is composed of a hydrogen separator 20 incorporating the hydrogen separation membrane 10 of the present invention and a heater 30 covering the hydrogen separator 20. Here, the hydrogen separation membrane 10 is the metal support 1 in the hydrogen separator 20.
1 is located below, the palladium alloy film 12 is located in the middle, and the metal plate 13 is located above. In order to separate the hydrogen gas from the raw material gas containing hydrogen using this separator S, the raw material gas G1 is introduced into the upper portion 21 of the hydrogen separator 20. Hydrogen gas in the source gas G1 is the hydrogen separation membrane 1
It passes through the palladium alloy film 12 of 0 and is taken out as the permeating gas H. On the other hand, the non-permeable gas G2 obtained by separating the hydrogen gas from the raw material gas G1 is taken out of the system from above the hydrogen separator 10.

The conditions for this hydrogen separation are that the temperature is room temperature to 600 ° C., the pressure in the upper portion 21 of the hydrogen separator 20 is normal pressure or higher, and there is a pressure difference from the permeate side.

[0039]

The hydrogen separation membrane of the present invention has a good sealability and heat resistance because the palladium alloy membrane is supported from both sides by the metal support and the metal plate in which a large number of pores of a predetermined pore size are perforated. In addition, it has excellent mechanical strength, can collect high-purity hydrogen, has excellent separation performance even at high temperatures, has good processability, and has a low manufacturing cost. In the method for producing a hydrogen separation membrane of the present invention, first, palladium and another metal layer are alternately laminated on one surface of the metal support by an electroplating method, and a large number of pores are punched from the other surface by an etching method, By further heat treatment, palladium and other metals other than palladium are mutually diffused to form a palladium alloy layer, in which pores are perforated by double-sided etching, and if necessary, a specific metal thin film is formed. It is possible to inexpensively manufacture a separation membrane having an excellent hydrogen separation ability by a relatively simple process of laminating deposited metal plates.

[0040]

EXAMPLES The present invention will be described in more detail below with reference to examples. Example 1 Production of Metal Support Coated with Palladium Alloy Film One side of 200 μm thick stainless steel (SUS316) was electroplated with palladium and silver alternately. The plating bath composition used was as shown below. The bath temperature is 30
℃, current density is 1A / d for palladium plating
m ² and 0.5 A / dm ² for silver plating. The total thickness of the plating is 30 μm, and the weight ratio is palladium: silver =
Multi-layer plating was performed so that the ratio was 80:20.

[Palladium plating bath composition] Pd (NH ₃ ) ₄ Cl ₂・ ・ ・ 30 g / kg NH ₄ Cl ・ ・ ・ ・ ・ 60 g / kg H ₂ O ・ ・ ・ Bal pH ・ ・ ・・ 9-9.5 [Silver plating bath composition] AgCN ・ ・ ・ ・ ・ 36 g / kg KCN ・ ・ ・ ・ ・ 60 g / kg K ₂ CO ₃・ ・ ・ ・ ・ 15 g / kg

Next, the etching treatment was carried out under the following conditions by pre-cleaning the plated material. [Resist coating conditions] Type of resist: Negative type acrylic polymer [PMER-N40DP manufactured by Tokyo Ohka Kogyo Co., Ltd.] Coating thickness: 7 μm [Exposure conditions] Ultraviolet wavelength: 375 nm Irradiation amount: 450 mJ [Etching conditions] Etching solution: Chloride chloride Aqueous iron solution (45 ° Be, 48
In this etching process, the hole diameter d of the small holes h is 10
0 μm, the shortest contact distance w between the plating and the metal support is 500
It carried out so that it might become (micrometer).

Production of Metal Material Having Many Pores on Both Sides Next, a stainless steel (SUS316) material having a thickness of 200 μm was pretreated and washed, and both sides were etched under the following conditions. [Resist coating condition] Resist type: Negative type acrylic polymer [PMER-N40DP manufactured by Tokyo Ohka Kogyo Co., Ltd.] Coating thickness: 7 μm [Exposure condition] Ultraviolet wavelength: 375 nm Irradiation amount: 450 mJ

[Etching conditions] Etching solution: ferric chloride aqueous solution (45 ° Be, 48
In this etching process, the etching solution was sprayed from both sides so that the central hole diameter of the metal plate was 200 μm. [Plating conditions] Plating solution; silver plating bath composition AgCN ・ ・ ・ ・ ・ 36 g / kg KCN ・ ・ ・ ・ ・ 60 g / kg K ₂ CO ₃・ ・ ・ ・ ・ 15 g / kg In addition, the bath water is 30 ° C., current The density is 0.5 A / dm ² ,
The plating was performed so that the thickness was 0.1 μm.

Production of Hydrogen Separation Membrane The metal support on which the palladium alloy membrane obtained above was plated was joined to the metal plate by laser welding to obtain a hydrogen separation membrane.

Hydrogen Separation Experiment The hydrogen separation membrane 10 obtained above was mounted on the hydrogen separator 20 shown in FIG. 3, and in this step, a mixed gas (74% by volume of hydrogen, 1% by volume of CO, CH ₄ 1) was used as a raw material gas G1. Capacity%, C
O ₂ 24% by volume). The permeated gas (hydrogen gas) and the non-permeated gas were separately measured in flow rate by the gas meters M1 and M2, and were introduced into the gas chromatograph GC to analyze the gas composition.

The experimental conditions are as follows. Temperature = 400 ° C. Pressure (pressure in the upper part 21 of the hydrogen separator 20) = 8.0 kg
/ Cm ² · G mixed gas flow rate = 1.0 Nl / min Outlet pressure (pressure in the lower portion 22 of the hydrogen separator 20) = normal pressure Repeated temperature rising / falling experiment (50 to 550 ° C)

The experimental results were as follows. After repeating 60 times, hydrogen gas concentration in permeated gas = 99.99% Permeation rate = 80.0 cm ³ / cm ² / min

Comparative Example 1 The metal support obtained by plating the palladium alloy membrane obtained above was directly used as a hydrogen separation membrane, and a hydrogen separation experiment was conducted in the same manner as in Example 1. The experimental results were as follows. After repeating 60 times, hydrogen gas concentration in permeated gas = 98.5% Permeation rate = 80.0 cm ³ / cm ² / min

[0050]

EFFECTS OF THE INVENTION According to the present invention, since a metal having a large number of pores is used as a support, it has excellent heat resistance and mechanical strength, can collect high-purity hydrogen, and even at high temperatures. Since a thin film of palladium or the like is formed with excellent separation performance by electroplating, a good hydrogen separation membrane can be easily manufactured in a short time with little labor. Further, since it has a structure in which a metal plate subjected to double-sided etching is adhered, it is resistant to thermal shock and the durability of the film is excellent.

[Brief description of drawings]

FIG. 1 is a schematic view showing a part of a hydrogen separation membrane production process, and FIG. 1 (A) is a view for explaining a state in which palladium and another metal thin film layer are deposited and formed on one surface of a metal support. 1B is an enlarged cross-sectional configuration diagram for explaining a state in which a large number of fine holes are formed by etching the other surface of the metal support of FIG. 1A, and FIG. 4) is an enlarged cross-sectional configuration diagram of the hydrogen separation membrane of the present invention.

FIG. 2 is a schematic view showing a part of a hydrogen separation membrane manufacturing process, and FIG. 2 (A) shows that palladium and another metal thin film layer are deposited / deposited.
FIG. 2B is a cross-sectional configuration diagram for explaining a state in which the formed metal support is laser-welded to a frame, and FIG. 2B is a cross-sectional configuration diagram for describing a state in which a metal material is laser-welded to a frame.
FIG. 2C is a cross-sectional configuration diagram for explaining a state in which FIGS. 2A and 2B are laser-welded at a frame portion to form a hydrogen separation membrane.

FIG. 3 is a schematic view of a hydrogen separation process using the hydrogen separation membrane of the present invention.

[Explanation of symbols]

 10 Hydrogen Separation Membrane 11 Metal Support 12 Palladium Alloy Membrane 13 Metal Material

Claims (2)

[Claims] 1. A metal support having a large number of pores having a diameter of 10 to 500 μm perforated by etching has a thickness of 1 to 1 on one side.
A palladium alloy film composed of 50 μm of palladium and another metal is deposited, and a large number of pores are preliminarily formed on both surfaces of the palladium alloy film by etching, and gold, silver, platinum, and palladium,
A hydrogen separation membrane comprising a stack of metal plates coated with a thin film of rhodium, copper or an alloy thereof. 2. The method for producing a hydrogen separation membrane according to claim 1, comprising the following steps. (1) A first step of alternately laminating thin films of palladium and another metal on one surface of a metal support by electroplating. (2) A second step of forming a large number of pores on the other surface of the metal support obtained in the first step by an etching method. (3) A third step in which the palladium of the metal support obtained in the second step and another metal thin film layer are heat treated at 500 to 900 ° C. to form a palladium alloy. (4) A fourth step of forming a large number of pores on both surfaces of the metal plate by an etching method. (5) If necessary, add gold to the metal plate obtained in the fourth step,
A fifth step of forming a thin film of silver, platinum, palladium, rhodium, copper or an alloy thereof by electroplating. (6) A sixth step of laminating the metal plate obtained in the fourth step or the fifth step on the surface of the palladium alloy film of the metal support obtained in the third step.