Whta's the Hydrogen Permeable Membrane?

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Whta's the Hydrogen Permeable Membrane?

The Hydrogen Permeable Membrane is special metal membrane.

It has the property of through only hydrogen under certain conditions.
Recently, researchers pay attention to this technology that is necesarry to the future hydrogen society.

Are there any holes or something?
No, ...there aren't.


Let's see the mechanism!

Most of the substance　surrounds us exists as the molecule include of gases.
However, the mechanism of The Hydrogen Permeable Membrane is related to atoms behavior.

The principle of the Hydrogen Permeable Membrane is 4steps as follows.

1. Hydrogen molecules in the mixed gas are adsorbed on the surface of membrane.
2. Hydrogen molecules separate into a hydrogen atom on the surface of membrane.
3. Hydrogen atoms enter into gaps of the alloy membrane and diffuse.
4. Hydrogen atoms move forward seem to pushed by hydrogen atoms coming after. Then Hydrogen atoms are recombined after passing through the membrane.

This principle uses a phenomenon called atom diffusion that hydrogen atoms enter into gaps of regularly arrayed metal atoms.
This gap is too small for atoms other than hydrogen atoms. Therefore, only hydrogen atoms can through the membrane and it is possible to separate hydrogen.
Using this property, we can refining high purity hydrogen more simply than conventional method by chemisorption(PSA method).。

However, there are problems to practical use as follows.

1. Hydorogen permeates only under certain conditions.
2. The strength of metal which has permeated hydrogen decreases due to hydrogen remains inside of the metal. （Hydrogen Embrittlement）
3. The metal that caused hydrogen embrittlement will be broken under hydrogen permeable condition.

For this reason, metals having hydrogen permeability are limited, and thus it is necessary to increase the strength of metal not depend on the material.

We are looking for practical optimum conditions of metal that can be a solution such as devising the shape of the membrane, regulation of hydrogen permeability and strength by structure control and alloying.

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