"Robert Clark" wrote in
oups.com:

Don Lancaster wrote:
Eeyore wrote:

Robert Clark wrote:


For my application I need a hydrogen/oxygen fuel cell to produce
the
H2O in liquid form. But in addition to the electrical energy, the
reaction releases a significant proportion of the energy as heat.
Enough heat in fact to turn the H2O released into steam. I know on
space missions they use fuel cells to produce liquid water but I
assume they use the cryogenic fuels onboard to liquify the water.
Is there a way to insure the water released is in liquid form for
the
H2 and O2 at room temperature?


Cool the water vapour.

His question shows a profound lack of understanding thermodynamics.

He should start with http://en.wikipedia.org/wiki/Latent_heat

http://www.tinaja.com/glib/energfun.pdf


Proton Exchange Membrane Fuel Cells.
"Hydrogen from the fuel gas stream is consumed at the anode, yielding
electrons to the anode and producing hydrogen ions which enter the
electrolyte. At the cathode, oxygen combines with electrons from the
cathode and hydrogen ions from the electrolyte to produce water. The
water does not dissolve in the electrolyte and is, instead, rejected
from the back of the cathode into the oxidant gas stream. As the PEFC
operates at about 175°F (80°C), the water is produced as liquid water
and is carried out of the fuel cell by excess oxidant flow."
http://dodfuelcell.cecer.army.mil/proton.html

So you have solved your problem, unless I am missing something. Do you
not want to use a PEM fuel cell for some reason?

Yours,

Bill Morse