jharmon12
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>90% Ethanol from E-85
Watching this video raises some questions.
http://www.youtube.com/watch?v=OfZgDkRwAUk
The first thing that comes to mind is this:
If one wants ethanol for use in the production of reagents, for use as a solvent, and possibly even in the production of nitromannite and mercury
fulminate, could one use this method to separate ethanol/water from the gasoline and use it for certain chemistry applications? After removing all
the gasoline with the employment of a separation funnel, one could then distill the ethanol from the water, using proper apparatus, to obtain 95%
ethanol.
The most obvious use for this application would be to keep one from having to produce and filter mash. The preceding video, of course, combined with
the action of distillation would not produce potable ethanol, but my thought is that it could be used for general chemistry applications where ethanol
is needed.
What do you think?
Thanks,
Joel
[Edited on 1-4-2013 by jharmon12]
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Organikum
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Thats for sure one of the most byzantine ideas lately. Whats the sense with this plan? You want alcohol for chemistry. Well buy it denatured or pure,
if you are not in a strict islamistic country it will be no problem. And even there denatured ethylalcohol will be available.
Otherwise a bucket, sugar, bakers yeast, yeast extract and some time will make the stuff. It is even potable then, how nice 
But theoretically you should be able to extract the alcohol with water from the gasoline and to distill the extract to yield some still gasoline
smelling alcohol. The concentration depends on your setup - for 95% you will need a big column with stillhead and lots of time.
/ORG
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Magpie
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I think this has some significant economic value for the home chemist, certainly in the US.
A gallon of gasoline costs roughly $4 in the US at the present. If 85% of that could be recovered it would put the price of ethanol also at
$4/gallon. This assumes that the recovered pure gasoline can be utilized as auto fuel, and why not?
$4/gallon is exceedingly cheap for pure ethanol. Just today I saw denatured alcohol for $30/gallon. The internet shows Everclear (95% drinking
alcohol) at $76/gallon on sale, not including shipping.
The single most important condition for a successful synthesis is good mixing - Nicodem
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jharmon12
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Magpie,
This is precisely why I want to make my own ethanol. The price of ethanol is excessive and it is available at the pump (E-85) for a fraction of the
price ($3.00/gallon here). Like you said, if you take the gasoline out of it, it is going to add up to .85 of a gallon of ethanol for $3.00. That is
cheap enough to make it worth looking into trying to make this work, for sure.
I was also looking at the possibility of salting out the water from the ethanol as a second step. Using potassium carbonate, one can separate the
alcohol from the water, to an extent. This would increase the concentration further. I could then use calcium chloride and distillation to get a
final product. So, a plan would be:
1. Add water to the E-85 to separate the alcohol/water from the gasoline.
2. Add potassium carbonate to the alcohol/water mixture to get out some (hopefully most) of the water out. The water will separate out from the
ethanol. One can use a dye to identify the water/salt layer. Repeat as necessary to increase the concentration.
3. Add calcium carbonate to absorb most of the last vestiges of water.
4. Distill the calcium carbonate/water/ethanol mix to hopefully get close to pure ethanol.
Thoughts?
Organikum,
Buy ethanol?? Why? Where is the challenge in that???
In regard to denatured alcohol, you don't know what kind of crap they put in that... Therefore, I can't use "denatured" alcohol when I need ethanol.
There is a difference, you know?
Thanks,
Joel
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Endo
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It is not that hard to figure out what the added component used to denature alcohol is. Usually in the ingredient list it will give a code which can
be referenced to 27 CFR 21.151 ( http://cfr.vlex.com/vid/151-denaturants-authorized-denatured... ) then the only remaining question is how much of the added compound is present.
Usually a little more research can help you decide if it will even matter for the use you are proposing. In many cases the family of compounds that
will carry over during a distillation of E-85 would probably give you more trouble than the compound used to denature alcohol.
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Magpie
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I wonder how much water has to be added to E85 before you get a phase separation that carries most all of the alcohol into the water phase?
After you get an alcohol/water phase I would distil it using a fractionating column. The 95% ethanol azeotrope will come off first as it has the
lowest bp, around 78°C. When the bp starts to rise then stop the distillation. Throw away the water. Put the gasoline fraction in your gas tank.
The 95% alcohol can be used "as is" or dried with molecular sieves to absolute alcohol.
So your cost will be that for the heat for distillation, and your time.
The single most important condition for a successful synthesis is good mixing - Nicodem
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jharmon12
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From doing some reading at other websites, it looks like you have to use an equal quantity of water of what you expect to get of the ethanol. So,
using 100 ML as an example, E85 would be about 85 ML of ethanol and 15 ML of gas. You would need 42.5 ML of water to get the most separation. Again
this is what I have read at another site during my research of this, and cannot verify if that is really true. This would leave you with a 50:50 mix
of alcohol:water.
What you said sounds pretty straightforward, Magpie. So you don't think it would be helpful to use the salt method to remove most of the water first,
(after taking the gasoline out, of course)?
Thanks again.
Joel
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Magpie
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Quote: Originally posted by jharmon12  | From doing some reading at other websites, it looks like you have to use an equal quantity of water of what you expect to get of the ethanol. So,
using 100 ML as an example, E85 would be about 85 ML of ethanol and 15 ML of gas. You would need 42.5 ML of water to get the most separation.
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Don't you mean 85mL water?
| Quote: Originally posted by jharmon12 |
So you don't think it would be helpful to use the salt method to remove most of the water first, (after taking the gasoline out, of course)?
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Will salt force ethanol out of a 50/50 mix with water? I wasn't aware that it would. If it does then by all means do so.
The single most important condition for a successful synthesis is good mixing - Nicodem
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elementcollector1
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Ethanol cannot be salted out, in contrast to acetone and isopropanol.
Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
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Magpie
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I just read on Wiki that below 70 torr ethanol does not form an azeotrope with water. This would be a slick way to bring the 95% alcohol to absolute.
The molecular sieves could then just be used to remove any traces of water.
The single most important condition for a successful synthesis is good mixing - Nicodem
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jharmon12
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Magpie,
There are a number of people doing demos of using a 50:50 mix of ethanol:water to separate the water from the ethanol. Theoretically, if you use
enough salt (any salt that will dissolve in water will work), you can get almost all of the water separated from the ethanol. Here is an example:
http://www.youtube.com/watch?v=1SS3-D-Aqr4
And yes, I meant 85 ML of water to mix with the 85 ML of ethanol. Sorry about the confusion.
Thanks,
Joel
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Magpie
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| Quote: Originally posted by Magpie |
Will salt force ethanol out of a 50/50 mix with water? I wasn't aware that it would. If it does then by all means do so.
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Very interesting. I suspect that what is happening is that osmotic pressure is forcing the water into the brine. Another way to look at is
differences in chemical potential or fugacity are at work.
The single most important condition for a successful synthesis is good mixing - Nicodem
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