Hey JimB,

Thanks for the info!

I'm embarrassed to reveal my ignorance here, but why is the ratio of CO2
to H2O relevant, rather than just the H2O? I've encountered other
combustion analyses that also focused on that ratio.

Appreciate your input.

Chuck


News f2s wrote:
"chuck" wrote in message
ink.net...

A molecule of alcohol does not contain a molecule of water.

As has already been pointed out in this thread and elsewhere,
and which I pray is not in dispute, is that ALL hydrocarbon
combustion yields water vapor as a product.

The question has been whether to expect a greater (and to
capture the essence of the thread, unacceptable) amount of water
vapor from a btu generated by burning alcohol, than from a btu
generated by burning, say, propane. Even better, we would like
to know how much more water vapor is generated from alcohol
combustion if in fact there is more. Because different alcohols
can be used (methanol, ethanol, isopropyl, etc.) combustion
chemistry is likely to be difficult to generalize.

Unless someone can provide the detailed chemical analyses, we
cruisers are stuck with testing and observation. Someone
suggests a hypothesis that burning alcohol will make my cabin
clammy. I conduct a thousand experiments, the results of which
contradict the hypothesis. Therefore, I have demonstrated that I
believe gravity is just hype! Now there's a brand of science
only Fox could sell.


If you ignore the heat output from each reaction, and just look at
the ratio of carbon dioxide molecules to water molecules produced,
there's no doubt that burning an alcohol produces more water.

Methyl alcohol, 2*CH3-OH + 3*O2 = 2*CO2 + 4*H2O
Ethyl alcohol, 2*C2H5-OH + 9*O2 = 4*CO2 + 12*H2O

Propane, C3H8 + 10*O2 = 3CO2 + 5*H2O

Benzene, 2C6H6 + 15*O2 = 12*CO2 + 6*H2O

On the heat equation, since alcohol is already partly oxidised,
you're likely to burn more of it to reach the same heat result.
That means yet more water.

Whether this matters is a subjective judgement . . . it obviously
offends some, and not others. Fine.

JimB