At 09:33 AM 5/7/01 +0200, Eugene.Leitl wrote:
> > One thing that will probably keep natural gas as the fuel of choice is that
> > hydrogen will embrittle and ultimately make steel gas lines fail. Also,
>
>That's an urban legend. It happened in the early days of ammonia synthesis,
>but you'll notice the pressure and the temperature at which that synthesis
>is conducted. At normal conditions you can use steel pipe just fine.
I did a search on "hydrogen embrittlement". The primary cause seems to be
wet environments, and cathodic protection of buried equipment, aside from
fabrication treatments. The pipelines would need to be kept very dry and
free from anything that could liberate hydrogen ions.
Most buried pipelines are equipped for cathodic protection. This should not
affect the inside of the pipe....
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 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.
Chuck Kuecker
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