Hybrid Car – More Fun with Less Gas

Compare Fuels Chemically - Page 4

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Posted by steamer on February 6, 2010, 5:34 pm

    --Just as he says. FWIW I once did a 'fractional distillation' of
kerosene and graphed the results. It was just a little amateur science: no
expert me. I was trying to find out why my steam boiler's kerosene burners
coked up so quickly and I found that the stuff starts to turn to carbon
at very low temperatures.

        "Steamboat Ed" Haas         :  To help the helpless  
        Hacking the Trailing Edge!  :  To comfort the fearful...
                   ---Decks a-wash in a sea of words---

Posted by harry on February 10, 2010, 8:23 pm


The thing you are looking for is the "CALORIFIC VALUE"
I imagine you measure it in Btu/lb over there, We have gone metric
here in the UK.

Posted by Curbie on February 11, 2010, 8:58 am


Well, after a couple days of chasing my tail (nothing new), I think
I've finally tracked down my trouble, the numbers I remembered for
gasoline (14.7:1) and methanol (6.5:1) are Stoichiometric ratios and
my spread-sheet calculates air/fuel ratios and there mot exactly the
same thing.

It seems Stoichiometric ratio considers air as just nitrogen and
oxygen where I was also considering the argon and CO2 present in air,
also I read somewhere on-line that the Stoichiometric ratio for
gasoline (petrol) is based on a different chemical mixture.

Anyway, it seems I was remembering Stoichiometric ratios and
calculating air/fuel ratios, but I'm pretty confident now that the
calculations are proper for my purposes.

Thanks for the link though, densities and specific gravities are next,
but at some point I'll go after heat values.

I'm old enough to have learned the imperial system in school and have
no clue what they teach these days, but I do use wikipedia a lot, so
over the last year or so I've been writing a series of conversion
routines for my spread-sheets so I have less and less trouble
understanding the results of metric equations.


Posted by harry on February 11, 2010, 7:49 pm

Well I was unfortunate enough to have been to school when we were
converting from one to the other.
You also need to look at excess air.
It gets a mention here.

There are lots of other factors too, mainly to do with corrosion and
pollution control of emissions.

Posted by Curbie on February 11, 2010, 9:18 pm


When I was a kid I didn't know what I was going to learn before I
learned it, let along any other options. It is what it is, I just
accept it and deal with it.


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