JP2003095616A - Hydrogen separating purifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the reduction of the thickness of a V-Ni alloy and provide a hydrogen separating purifier in which the thinned V-Ni alloy plates are mounted as several shapes of partition walls. SOLUTION: The V-Ni alloy plate is provided with front and rear surfaces covered with an alloy containing Pd or an alloy containing Pd, and the V-Ni alloy plate containing nitrogen of 5-30 atom.% and having a thickness of 0.1 mm-0.001 mm is mounted as a partition film by which hydrogen is purified.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The invention of this application relates to a hydrogen separation and purification apparatus. More specifically, the invention of this application is such that only hydrogen is selectively separated and purified from a mixed gas containing hydrogen or an unpurified hydrogen gas containing impurities,
The present invention relates to a hydrogen separation and purification device capable of producing ultrahigh-purity hydrogen of 99.99999% or more, so-called Seven Nine or more.

[0002]

2. Description of the Related Art A hydrogen separation / purification device using a Pd alloy for a hydrogen permeable membrane has been developed as a hydrogen separation / purification device for producing ultra-high purity hydrogen, which is an important energy source for fuel cell automobiles, for example. Although it is at the level of practical use, on the other hand, Pd as an alloy raw material is very expensive and
There is a problem in the transmission characteristics at low temperatures below ℃.

Recently, by the inventors of the invention of this application,
A V-Ni alloy containing 5 to 30 atomic% Ni was found to have high hydrogen permeability, and it is expected that the price will be reduced.
The Ni alloy has a problem that it has poor workability and it is difficult to make it into a thin plate. That is, the V-Ni alloy is easily oxidized and the melting point of the oxide is low, so that hot rolling is difficult. In addition, if the ingot is directly cold-rolled, cracks are likely to occur, so 1 mm
The only way to achieve the following thickness is to cut the ingot and then polish it to make it thinner. For this reason, it was very inefficient to process the V-Ni alloy into a film shape or a pipe shape in order to apply it to a hydrogen separation / purification device, and it was far from practical use.

The invention of this application has been made in view of the above-mentioned circumstances. As described above, the V-Ni alloy, which has been considered difficult to be thinned, has been thinned into various shapes. It is an issue to be solved to provide a hydrogen separation and refining device mounted as a partition wall.

[0005]

Means for Solving the Problems The inventors of the present application
As a result of diligent studies to solve the above-mentioned problems, by applying sheath rolling to a V-Ni alloy having high hydrogen permeability, it is possible to make the thinnest plate as thin as 0.01 mm, and Thinning is relatively easy, and
The thinner the hydrogen, the larger the hydrogen permeation flow rate obtained, and the knowledge that it is possible to efficiently purify a large amount of hydrogen at a low temperature to an ultra high purity of 99.99999% or more, so-called Seven Nine, and sheath rolling. Besides, 0.001m thick by sputtering, vacuum deposition, ion plating, etc.
We obtained the finding that V-Ni alloys up to m can be produced, and completed the invention of this application.

That is, the invention of this application has both front and back surfaces.
A V-Ni alloy coated with Pd or an alloy containing Pd and having a thickness of 0.1 mm to 0.001 mm containing 5 to 30 atomic% of Ni is mounted as a diaphragm, and hydrogen is purified by the diaphragm. A hydrogen separation and purification device (claim 1) is provided.

Further, the invention of this application is such that the V-Ni alloy has a thickness
It is a sheath-rolled thin plate of 0.1 mm to 0.01 mm (claim 2), and the V-Ni alloy contains Mn and other elements that do not adversely affect hydrogen permeability as unavoidable impurity elements or at most 5 atomic%. Up to (claim 3), the diaphragm,
It has a flat plate shape, a bellows shape, or a pipe shape (Claim 4), and one pipe-shaped diaphragm is arranged or a plurality of pipe-shaped diaphragms are arranged in parallel (Claim 5). Are provided as one aspect, respectively.

Hereinafter, the hydrogen separation and purification apparatus of the invention of this application will be described in more detail with reference to the drawings.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION FIG. 1 <a><b><c> is a cross-sectional view schematically showing an embodiment of a hydrogen separation and purification apparatus of the invention of this application.

In the hydrogen separation and purification apparatus of the invention of this application,
As described above, both front and back surfaces are coated with Pd or an alloy containing Pd, and a V-Ni alloy containing 5 to 30 atom% of Ni is sheath rolled,
It is made to have a thickness of 0.1 mm to 0.01 mm by sputtering, vacuum deposition, ion plating, etc. This is attached as a diaphragm (1), and hydrogen is generated by this diaphragm (1).
Purifies to ultra-high purity of 9.99999% or more, so-called Seven Nine.

The sheath rolling can be carried out, for example, by using a stainless steel tube or the like as a sheath tube, inserting a V-Ni alloy ingot in the sheath tube, enclosing the sheath, and hot rolling the sheath tube together. By this sheath rolling, it has become possible to reduce the thickness of the V-Ni alloy, which was considered difficult until now, and the thickness of the diaphragm (1) can be 0.1 mm or less, and the thinnest, up to 0.01 mm. Moreover, the thinning thereof is relatively easy, and the thinner the hydrogen, the larger the hydrogen permeation flow rate can be obtained, and the large amount of hydrogen can be efficiently purified at a low temperature. When the thickness of the diaphragm (1) exceeds 0.1 mm, the diaphragm (1)
The flow rate of the hydrogen gas that permeates through becomes insufficient, which causes a decrease in the hydrogen separation and purification processing rate, which is not preferable.

When a V-Ni alloy is produced by sputtering, vacuum deposition, ion plating, etc., the thickness
Thin plates or thin films up to 0.001 mm can be easily manufactured.

The above V-Ni alloy contains up to 5 atomic% of Mn and other elements as unavoidable impurity elements, or third and fourth elements, etc., as long as the hydrogen permeability is not adversely affected. be able to.

More specifically, the diaphragm (1) can be mounted inside the cabinet (2) provided in the hydrogen separation and purification apparatus, but its shape is not particularly limited. For example, in addition to the flat plate shape as shown in FIG.
It can be bent into a bellows shape as shown in FIG.
The flat plate-shaped and bellows-shaped diaphragms (1) can be arranged so as to partition the cabinet (2).

Further, the diaphragm (1) may be formed in a pipe shape as shown in FIG. 1 <c>. Thin V-Ni
The alloy has sufficient bending strength to be processed. The cross-sectional shape when made into a pipe shape is star, round, oval,
Various shapes such as a quadrangle, a triangle, a pentagon, a hexagon, and an octagon or more polygon are possible. In the case of a pipe shape, for example, electron beam welding, diffusion bonding, etc. can be applied to the manufactured thin plate. One pipe-shaped diaphragm (1) may be arranged in the cabinet (2) or a plurality thereof may be arranged in parallel. When the pipe-shaped diaphragm (1) is provided in the cabinet (2), it can be joined by using, for example, a swagelok joint or electron beam welding.

Reference numeral 3 shown in FIG. 1 <a><b><c> is a gas introduction portion to the cabinet (2), and reference numeral 4 is hydrogen after purification by the diaphragm (1). It is a gas outlet. Reference numeral 5 is a drain of residual gas.

Further, in the hydrogen separation and purification apparatus of the invention of this application, both the front and back surfaces of the V-Ni alloy are coated with Pd or an alloy containing Pd, which is a surface that deteriorates the hydrogen permeation performance of the V-Ni alloy. This is to prevent oxidation and to accelerate the dissociation reaction into atomic hydrogen, that is, the separation reaction, which is necessary when the hydrogen gas, which is a diatomic molecule, dissolves in the V-Ni alloy.
The method for coating Pd or an alloy containing Pd on both front and back surfaces of the V-Ni alloy is not particularly limited, and a vacuum deposition method, an electroplating method, an electroless plating method and the like can be considered. Among them, the electroless plating method is preferable because it can uniformly coat even a complicated shape. The thickness of Pd or the alloy containing Pd to be coated is not particularly limited, and may be set appropriately in consideration of the total thickness of the diaphragm (1). The coating of Pd or an alloy containing Pd is performed after the production of the diaphragm (1).

Hereinafter, examples of thinned V-Ni alloys mounted in the hydrogen separation and purification apparatus of the invention of this application will be shown and the characteristics thereof will be specifically shown.

V-15 atoms by arc melting method in argon
% Ni alloy was melted. After removing the oxide film on the surface formed on this V-15 atomic% Ni alloy, this was placed in a stainless steel tube, and the stainless steel tube was sealed by electron beam welding in vacuum. Then, 1150 together with the sealed stainless steel pipe
Sheath rolling was performed by hot rolling to a thickness of 5 mm at ℃. Then, solution heat treatment was performed at 1200 ° C. This solution heat treatment for quenching is a treatment for quenching a high temperature state in which Ni atoms are uniformly dissolved in V and lowering it to a low temperature, and realizes hydrogen permeability of the V-Ni alloy and workability into various shapes. Then divide into four, 0.1mm, 0.3mm,
Cold rolling was performed to a thickness of 0.4 mm and 1.1 mm at room temperature using a general roll. By cold rolling, the thin plate surface is finished beautifully. No cracks or cracks were found on any of the thin sheets after rolling. It has been confirmed that it is possible to reduce the thickness of the V-Ni alloy, which has been considered difficult to reduce the thickness.

A disk-shaped sample having a diameter of about 12 mm was cut out from each of the thin plates prepared, and the surface thereof was mechanically polished using emery paper or alumina abrasive grains and chemically polished for etching to a mirror surface, followed by vacuum deposition. Both sides of the sample were coated with Pd to a thickness of about 0.1 μm.

The sample thus produced was mounted in a hydrogen permeation test device and a hydrogen permeation test was conducted. During the test, the sample temperature was set to 523 K, hydrogen pressure of 500 torr was applied to the inlet side, and the outlet side was evacuated. Then, the hydrogen permeability was compared with a practical level Pd-25Ag alloy. The result is shown in the graph of FIG. In the graph of FIG. 2, the vertical axis is the hydrogen flux, but the hydrogen flux is
It means the volume of hydrogen flowing per unit area and per unit time.

As can be seen from the graph of FIG. 2, the hydrogen permeation flow rate increases in inverse proportion to the thickness of the sample, and the V-15Ni alloy thin plate coated with Pd on both the front and back sides is higher than the Pd-25Ag alloy. The hydrogen permeation flow rate increases.

Further, when a bending test was performed on a V-15Ni alloy thin plate having a thickness of about 0.1 mm and having both front and back surfaces coated with Pd, sufficient bending workability was shown, and cracks and other defects were found in the curved portion. There wasn't. The weldability was also examined using an electron beam, but the welded part was sound and no cracks or other defects were observed. Figure 1 <a><b><c>
It is confirmed that the diaphragm (1) having various shapes exemplified in 1. is feasible.

Of course, the invention of this application is not limited to the above embodiments. Configuration and structure of the hydrogen separation and purification device excluding the diaphragm, shape of the diaphragm, manufacturing conditions,
It is needless to say that various aspects are possible for details such as the thickness of Pd or an alloy containing Pd coated on both front and back surfaces.

[0025]

As described in detail above, according to the invention of this application, thinning of a V-Ni alloy, which has been difficult to be thinned, is realized, and a hydrogen separation / purification device equipped with this as a partition wall of various shapes is provided. It is expected that it will be possible to produce ultra-high purity hydrogen of 99.99999% or more, which will be provided and will be an important energy source for fuel cell vehicles, at low cost.

[Brief description of drawings]

1A to 1C are cross-sectional views schematically showing one embodiment of a hydrogen separation and purification apparatus of the invention of this application.

FIG. 2 is a graph showing the relationship between the reciprocal of the thickness at 523K and the hydrogen flux of the sample mounted in the hydrogen permeation test apparatus.

[Explanation of symbols]

1 diaphragm 2 cabinets 3 gas introduction section 4 Hydrogen gas outlet 5 drain

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B01D 71/02 500 B01D 71/02 500 C22C 27/02 101 C22C 27/02 101Z // H01M 8/06 H01M 8/06 RF term (reference) 4D006 GA41 MA02 MA03 MA31 MB04 MC02X NA31 NA50 PA02 PB18 PB66 PC80 4G040 FA02 FB09 FD04 FE01 5H027 AA02 BA16

Claims (5)

[Claims] 1. V-Ni having a thickness of 0.1 mm to 0.001 mm, which is coated with Pd or an alloy containing Pd on both sides and contains 5 to 30 atom% of Ni.
A hydrogen separating and refining apparatus characterized in that an alloy is mounted as a diaphragm, and hydrogen is purified by the diaphragm. 2. The hydrogen separation and purification apparatus according to claim 1, wherein the V-Ni alloy is a sheath-rolled thin plate having a thickness of 0.1 mm to 0.01 mm. 3. The hydrogen separation and purification apparatus according to claim 1 or 2, wherein the V-Ni alloy contains Mn or other elements that do not adversely affect hydrogen permeability as an unavoidable impurity element or up to 5 atom%. 4. The hydrogen separation and purification apparatus according to claim 1, wherein the diaphragm has a flat plate shape, a bellows shape, or a pipe shape. 5. The hydrogen separation and purification apparatus according to claim 4, wherein one pipe-shaped diaphragm is provided, or a plurality of the diaphragms are arranged in parallel.