On Fri, 19 Jul 2002, Roman Black wrote:

>Martin McCormick wrote:
>>
>>         There was a PBS "Nova" special about this topic in the
>> early nineties and someone had a fleet of busses set up to be
>> able to accept either hydrogen or gasoline as fuel.  Believe it
>> or not, they sort of worked.
>
>
>I had a magazine from 1977 that showed photos of
>Yul Brown and his lab, he was running a typical car
>engine on the oxygen/hydrogen gas mix straight from an
>electrolysis cell. From memory this just required
>changing the ignition timing, replacing the carbie
>with a valve and injecting a small amount of water
>to keep things cool. I wish I hadn't lost the magazine.
>-Roman

I believe that you saw this but did the pictures show the direct busbar
connections to the nuclear power plant behind his garage ? Because if you
run some numbers you will have some very interesting conclusions wrt. what
you saw. A gas flow sufficient to run an auto engine requires a serious
serious electrolysis cell system, which by the way works best at about 180
degrees C under pressure and has alimited continuous operation life. Of
course the film showed this, no ? The power level required to run this is
about on par with the one required to run a small industrial manufacturing
unit (couple tens kW or hundreds of kW, roughly the power output of the
engine divided by the efficiency of the engine, of the electrolysis cell
etc etc. Hint: 1HP = 745.69987 (?!) W).

If he ran the motor on load then it was likely nearer 200kW, not
accounting for losses in either electrolyzer or engine, which would put
the figure beyond 500kW without trying hard. That's 500kW electrical power
input, not accounting for any cooling or other unimportant inexpensive
small quiet unobtrusive things (like small unobtrusive radiators that cope
with 100+kW to keep the electrolyzer from melting down and small
unobtrusive inexpensive uncooled busbars that feed the e.  cell(s) with
hundreds of amperes etc).

Or to put it in shorter words: If you run an engine off an electrolysis
cell then the electrolysis cell input is about P1 = Pmotor / (Nmotor *
Ncell) which for a small car engine would be Pmotor = 40hp, Nmotor = 0.2,
Ncell = 0.7 -> 218kW. Out of which a third (about 70kW) is heat dispensed
by the electrolysis cells alone. I suppose that your scientist had a
special meter installed. Or maybe they showed just the running engine as
it looked cooler like this.

I hope that I did not bust your dream(s). Of course in aerospace and
military apps the fuel is generated elsewhere in a factory sprawling over
miles of land, with hundreds of employees and astronomical power utilities
bills, funded by taxpayer's money and the users have a small button on a
panel that says something like 'push here to start fuel cell', and this
looks really cool in movies and in presentations. Of course it is
extremely useful.

Peter

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