[Stoves] Burning low quality ethanol

Sat Sep 1 09:12:45 EDT 2007

Dear Paul

Making low grade alcohol is the easiest thing to do.  As you boil an
alcohol/water mix resulting from fermentation, the first stuff that
evaporates is a very low-grade alcohol, and all you have to do is to
condense it to remove it from the system.  It will contain more alcohol than
the original fermentation liquor, but will still be real low grade.  If you
reboil this stuff, you will concentrate it some more - and so on, all the
way up to 96.4%  When the vodka boys tell you about "triple distillation,"
some do this concentration step three times, then add water to drop the
alcohol concentration to around 45 Proof (which is about 24% alcohol). 

I once bought some hooch on a Moscow street in mid-winter which the seller
described as "Harosch"(Excellent). The product was labelled "Rasputin" once
you had transliterated it, and the seller pointed to the label saying (I
thought) 70 proof.  I had a good dose of antifreeze when I got back to my
hotel, and felt I would die.  Getting out my dictionary, I found the word
was not "Proof" but "percent" - in proof terms it was around 140 proof.

Bootleggers of the world unite! 

Philip

-----Original Message-----
From: stoves-bounces at listserv.repp.org
[mailto:stoves-bounces at listserv.repp.org] On Behalf Of Paul S. Anderson
Sent: 01 September 2007 07:03
To: crispin at newdawn.sz; Discussion of biomass cooking stoves; Crispin
Pemberton-Pigott
Cc: Harry Stokes - alcohol - Pennsylvania; 'Discussion of biomass cooking
stoves'
Subject: Re: [Stoves] Burning low quality ethanol

Dear Crispin, Anil, William, Philip and all,    (If you are interested in
alcohol stoves or alcohol fuel, this message should be important.  If not
interested, don't bother.)

Anil, can you direct us to your 1984 publication on the Internet, please.

Rajvanshi, A.K., 1984. Distillation of Ethyl Alcohol from Fermented Sweet
Sorghum Solution by Solar Energy, Final report submitted to Department of
Non-Conventional Energy Sources, New Delhi.

You say that the people can make low-quality (high water content) ethanol.
I want to know those methods.  They should be distinctly different from the
"first-pass" of ethanol production in modern distilleries that yields only
5% of water in the alcohol.  Nobody else has said anything about the
production of low-quality ethanol.  Please provide the info or links.

Your paper about your alcohol stove says that you were intentionally
diluting the regular alcohol with water.  The purpose was to make the stove
safer, correct?  Is there any other reason to dilute otherwise good ethanol?

But the water content must be raised from ambient temperature to 100 deg C,
and then even more heat (latent heat) is needed to make the liquid water
into steam (still at 100 C).  That seems like a major amount of heat energy
expended just because of the water content.  Safety is important, but at
what trade-off? Discussion is needed.

To Philip Lloyd:  Please write.  Your comments would be appreciated.

To William Carr who wrote:

> .... in the more general area of alcohols,  Butanol is the solution 
> to the problem.    It doesn't have to be  double-refined to burn 
> well, as ethanol does.

I am referring to the SINGLE-refined ethanol, which is fine for thermal
applications.  The double-refined is necessary for placing ethanol into
gasoline, (and probably for some other uses where no water is tolerated.)

I did find your butanol comments to be quite interesting.  What is the
"problem"
that prevents butanol from getting the funding and political support that is
given to ethanol?

And to Crispin Pemberton-Pigott:   (much snipped)

You mention the wikipedia article.  It is a modern classic that is
frequently
cited, along with the material at     zenstoves.com
http://en.wikipedia.org/wiki/Beverage_can_stove

Wikipedia "lists a couple of patents issued for them at the bottom."  I have
not yet looked at them.  Anyone able to make quick comments?

> I am preparing another go at the
> calculation of heat available from burning ethanol.

I look forward to that calculation.
>
> In industry the target for 1 pass through a distillation is 5% water 
> or less. Given the close condensation temperatures, that is pretty 
> good and that is what is sold normally.

Unfortunately, in the USA I seem to only get the 100% stuff at about US$12
per gallon (nearly $4 per liter).  Yet in Ethiopia, the market price of
ethanol (what Project Gaia pays) is only US 25 cents (one sixteenth what I
pay). (Joke:  Where is George W. Bush when I need him??)

> If you have more water than that, someone started out at 5% and 
> diluted it to sell water at $1000 a cubic metre.

An excellent point.  And think of the added transportation costs.  Ethanol
should not be watered intentionally (unless for safety that Anil cites??).

But if Anil or others can show how to economically produce ethanol with a
range of 50% to 6% water content, then there is a different story.  The
issues then include the wasted heat energy to boil off the water, unless
there is selective vaporizing that liberates the alcohol and leaves the
water behind (as is the case with the self-pressurized alcohol stoves like
the beverage can stoves and the Lily stove).

> The ethanol gasifiers (which you seem to have) overcome this although 
> you still pay a lot for the water.

Please allow me to shout once:  Alcohol stoves VAPORIZE a liquid, and DO NOT
GASIFY.  Gasifiers are generally accepted to refer to making gases from
solid dry biomass.

> What is the latent heat of evaporation of ethanol? And its specific heat?

Good questions, and I do not have the answers.  Help please, anyone.

> One problem I see is that in some countries you are not allowed to 
> heat the fuel in the tank above the evaporation point at any time 
> because it is a safety hazard. You can pressurize it, but not heat it 
> because you can easily depressurize it but not cool it quickly should it
fall over.

I certainly hope I do not need to get involved with changing of laws. 
Seriously, I have found no problems with heating these self-pressurizing
alcohol burners.  Reasons are:

1.  Construction with numerous holes in the top.  The pressure is quite low.

2.  I restrict my units to quite small sizes.  7 cm diameter (3 inch)
tincans are excellent.  I have gone up to 15 cm (6 inch) diameter.  These
stoves work on the principle of heat from the fire being able to heat the
metal cans that in turn heat the alcohol that becomes vaporized.  This
heating is selective, meaning it occurs at the metal surfaces.  Vaporization
of some molecules will cause cooling of the surrounding liquid, keeping the
majority of the liquid below the vaporization point until that liquid
reaches the warm metal.  When the liquid is held in a fiberglass or ceramic
fiber material inside the burner-can, the liquid does not readily flow,
especially not in the upper part of the container because gravity keeps the
fluid tending to sink lower into the can.  The use of fiberous fillings is
found in the CleanCook stove (and other Dometic AB stoves) and in the Lily
burner.  I did not see any reference to fiberous fillings in the beverage
can stoves, but it could be used there.

And when the fire is extinguished, the vaporization (if fluid is still
present)
quickly drops (perhaps 5 to 10 seconds later), and not even a match at the
vapor outlets will re-ignite the can.  In some ways the steel of the Lily
burner might be superior for safety over similar stoves made of aluminum or
brass, but that topic also needs further thought and experimentation.

I have tipped the Lily burner intentionally, and done a few other things
without being very careful, and I have never had a safety-threatening
situation at my workbench.  But of course, EVERY stove with any fuel could
cause a fire under some irregular circumstances.  This will be a topic for
continual vigilance.

> Come to think of it, that would prevent the Lily stove reaching some 
> markets.

If so, then I will need to focus on the places that will allow such stoves.
Please send me a list of the places that you know of that have restrictions
against small containers of alcohol being made warm, but not warming the
entire liquid contents to the temperature of vaporizing.

Paul
--
Paul S. Anderson, Ph.D., Geography professor - Emeritus
Telephone:  USA-309-452-7072 (residence and office) Internet site:
www.ilstu.edu/~psanders For my gasifier stoves info, go to:
http://bioenergylists.org/contributors#Paul_Anderson

----------------------------------------------------------------
This message was sent using Illinois State University Webmail.

_______________________________________________
Stoves mailing list
Stoves at listserv.repp.org
http://listserv.repp.org/mailman/listinfo/stoves_listserv.repp.org
http://stoves.bioenergylists.org
http://info.bioenergylists.org