[ausev] Some familiar units to describe the HHO generator

[Brian Lasseter]

On Sun, Jul 6, 2008 at 2:25 PM, Gil Dawson <Gil at gil.dawson.name> wrote:
> thus:
>
>    The hydrogen gas extracted from a gallon of water
>    can produce more miles driven
>    than a pint of gasoline.
>
> That seems reasonable to me.  Does it seem reasonable to you?

The burning of Hydrogen produces 286 kJ/mol...
http://en.wikipedia.org/wiki/Hydrogen#Combustion
Gasoline has an energy content of 44.4 MJ/kg...
http://en.wikipedia.org/wiki/Gasoline#Energy_content
A mole of hydrogen weighs only 2 grams...
http://en.wikipedia.org/wiki/Mole_%28unit%29
Thus a kg of hydrogen has an energy content of 143 MJ/kg compared to
gasoline's 44.4 MJ/kg.

A gallon of water electrolyzed produces 0.40kg of hydrogen for 57MJ of
energy content.  One pint of gasoline is 473cm^3, and the density of
gasoline is around 0.74 g/cm^3.  So... a pint of gasoline weighs
0.35kg for 15.5MJ of energy content.

So, you are correct that a gallon of water takes can produce more
miles driven than a pint of gasoline.

Granted, it would take 140MJ of energy to electrolyze the gallon of
water at 100°C (for 0.4kg of Hydrogen)...
http://en.wikipedia.org/wiki/High-temperature_electrolysis



Or, stated another way, it would take 1.1 gallons of gasoline to give
you the energy to electrolyze one gallon of water which would produce
enough hydrogen to deliver the same energy content as 0.45 gallons of
gasoline.

Hence, you are better off burning the gasoline to power your car than
to bother with any sort of intermittent step involving hydrogen or
water.



-- 
TTFN,
Brian "Lasso" Lasseter

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