Re: Fuel cells (was Re: jeff's cyborg cells)

From: Chuck Kuecker (ckuecker@mcs.net)
Date: Fri Jun 04 1999 - 06:32:15 MDT


At 10:18 PM 6/2/99 -0700, Eugene Leitl wrote:
>
>The chiefest problem with reforming higher alcanes is a) the surface
>of the reforming catalysator gets mucked up progressively b) it's
>difficult to keep the CO content low (it should be present as
>traces only), and CO poisons the Pt/Pd electrode surface at the
>temperatures used (you're limited by the polymer electrolyt here).
>
>'gene

Looks to me that all current fuel cells work only with hydrogen - the
carbon bonds, if any, are wasted as CO2 without contributing to the
electrical output. Perhaps in the high temperature cell, this energy helps
keep the cell hot?

I can see why hydrogen is easy to use - it's just a proton when ionized,
and can be exchanged easily to drive current flow. I guess what I am really
looking for is some chemistry that can take a more complex and more easily
stored/handled hydrocarbon and convert all of the bond energy as combustion
does, but use the energy to drive the electron pump. I am not enough of a
chemist to even guess if this is possible.

Fuel cells are about 50% efficient, if I recall rightly - so even losing
50% of the bond energy due to reforming a fuel to hydrogen, we get better
overall efficiency with the fuel cell. I just get itchy when ANY energy
gets thrown away without a chance to do work.

If I recall right, large methane fueled fuel cells were proposed for
installation in New York City to generate power - and the waste heat could
then be used for process or building heat. Does anyone know if this scheme
was actually installed?

Chuck Kuecker



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