From: Robert Coyote (coyyote@hotmail.com)
Date: Mon May 07 2001 - 09:31:10 MDT
If traditional odiferants cause problems in fuel cells, don't use
traditional odiferants
surely someone can come up with substitutes...
-----
The X that can be Y is not the true X
On Mon, 7 May 2001, Chuck Kuecker wrote:
>
> Main gas lines operate at significant pressures - the long transport
lines
> are the ones I am concerned with. Ultimately, a specially coated line
will
> be developed to prevent stress cracks and embrittlement, but the present
> infrastructure will limit us to methane (or butane!) for quite a while.
The issues of (largely electrolytic) hydrid and atomic hydrogen
embrittlement and high-pressure/high-temperature typically do not occur
together. The steel embrittlement was an early plague of the Haber Bosch
process, which occurs at 500 atm and 450 deg C. Now these are not the
typical conditions under which a pipeline is operated, especially
considering the temperature.
> The problem of letting humans sense H2 leaks is a thorny one, if the
> traditional odiferants cause problems in fuel cells. One ray of hope I
just
> read about (Science, 4/21/2001) is a mid temp (160 C) fuel cell that does
> not use platinum catalysts. Perhaps this chemistry is resistant to
poisoning.
Methane high-temp cells with nickel electrodes are pretty much immune to
poisoning.
In any case, one would want to generate the hydrogen locally, either from
methane, using existing natural gas infrastructure, or from water via
electrolysis or photolysis, which renders above arguments nilpotent.
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