[Gasification] Gasification Digest, Vol 19, Issue 10

[AJH]

On Sat, 12 Jan 2008 21:40:43 -0800, Mark Ludlow wrote:

>In theory, if you had a high pressure reservoir of mixed gasses and a
>membrane with apertures sized to exclude everything except H2, the H2 would
>flow to the receiving reservoir as long as the partial pressure of H2 in the
>source reservoir exceeded that of the receiving reservoir.

Sounds plausible to me, the basic technique is used in fuels cells and
the oxygen concentrators that hospitals use.

I think the point about the pressures and "waiting a long time" has
been covered by other answers, you need to pump the hydrogen away from
the receiving side to maintain the differential pressure.

Interesting to hear Art's story, I think nanotube technology does
something similar except the mixture is pumped at high pressure into
the nanotube medium, the hydrogen fits in the nanotubes but the other
gases don't, there must be some form of hysterisis whereby the other
gases are purged and then the hydrogen retrieved but I'd have to ask
about the details.