re: homemade balloon wine
19 nov 2000
lou pogoda writes:
>>>...how much heat does it take to evaporate a gallon of alcohol from
>>>8.33 gallons of water and alcohol mix when the alcohol is 12% of the
>>>total? and how much can you get from burning the resulting gallon?
the chem/phys handbook says the heat of vaporization of ethyl alcohol
(c2h6o) is 9673.9 calories per gram mole (50 grams) and the heat of
combustion is 326.68 calories. the difference is about 21k btu/lb, vs
about 10k btu/lb for burning dry wood...
>>...if it takes 1,000 btu to evaporate a pound of alcohol and we get
>>10,000 by burning it, we might be ahead of the game with a good heat
>>exchanger and enough insulation, especially if we ferment indoors,
>>and count the heat of fermentation.
hey, what happened to the heat of fermentation?
>but you're not evaporating just a pound of alcohol - you have to heat
>the whole mix until it's warm enough for the alcohol to vaporize at
>some useful rate.
seems to me that's a one-time thing. it makes no ongoing difference,
given enough insulation and an efficient heat exchanger. we could do
all the numbers, but who cares?
>>>i've always read that one of the reasons the world runs on petroleum
>>>instead of alcohol is that producing the alcohol uses more energy than
>>>you can get from burning the stuff.
>>that may well be true, with conventional agriculture.
>and where, pray tell, is the feedstock going to come from if not
gathering windfall apples or the remains of cidermaking? fermenting piles
of out-of-date bread or fruits or sticky buns from grocery store shelves?
what will you do when the oil runs out?
>anyway, even industrial distilling operations consume more energy in the
>distallation process than is available from burning the product.
is that universally true, or another ken h'ism? they might add more
insulation or better heat exchangers, or let every bit of the heat
warm a house, vs wasting it.
>>>in any case, such an arrangement sounds a little overly complicated -
>>>why not just burn the grain or fruit or whatever you're using as
>>>feedstock for the still directly and be done with it?
>>could be the moisture content is too high...
consider a pile of apples, or pig manure... yes, you distill water
out of it, burn the dry material, and condense the water vapor to
recover the latent heat, but...
>the moisture content of a 12% alcohol and water mix is far higher...
that seems more suitable as a fuel, with an efficient still.