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Author: Subject: Distilling ethanol to purity
Amy Winehouse
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[*] posted on 30-3-2012 at 16:14
Distilling ethanol to purity


Hey,

I have 75.5% ethanol and I am trying to get to the ~95.5% azeotrope so I can dry and get as close to anhydrous as possible. I'm just gonna add drying agent after I obtain the azeotrope. My question is, about how many distillations will I need until I get the azeotrope? I'm already on the first one, and what information can I gain from the distillation temperature in relation to what percentage of ethanol I have?

Thanks! :)
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Magpie
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[*] posted on 30-3-2012 at 17:40


Get yourself a fractionation column and you will only need one. Otherwise I would guess 5-10, but this is just a wild guess. And you will leave most of your ethanol behind in the pot- very wasteful and labor intensive.



The single most important condition for a successful synthesis is good mixing - Nicodem
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Amy Winehouse
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[*] posted on 30-3-2012 at 19:36


Well, the ethanol/water azeotrope supposedly boils at 78.6 C, and I'm on my second distillation and the initial temperature is 80. I'm waiting until the temperature gets to about 85 then starting over, that's what I did last time. From what I understand, the two will contribute their vapor pressures and fight against atmospheric pressure, and the distillate that initially comes over is almost pure ethanol and as it progresses, the composition slowly includes more and more water. So if I throw away the last 10-15% or so every time and do it 3-5 times, I will be left with ethanol pure enough to dry to ~98-99%, right? This may be way off haha, but I am unable to acquire anhydrous ethanol or even 95.5% so it's the only way. I broke my fractionating column last month :(:(:(:( but I have a coiling column I havent used in a while, I suppose I could just use that as a fractionating column.

[Edited on 31-3-2012 by Amy Winehouse]
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[*] posted on 31-3-2012 at 00:59


Well thats the time some copper tubes and fittings help you more then a coiling column. The howto is all over the net for making booze :D
Build youself a decent column with stillhead - thats really easy and cheap and can be easily fitted to glassware if desired - really you cannot go without.

And for all this hard work you have to do ;) her comes the reward:
Look into the properties of a mixture of ethylene glycol, alcohol and water under distillation and almost anhydrous ethanol can be done.

After that get some sugar, bakers yeast and a small barrel and moonshine some high octane booze which compensates for all the expenses and worktime invested. If sold for far more :o

regards
/ORG
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franklyn
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[*] posted on 31-3-2012 at 18:25


http://www.sciencemadness.org/talk/viewthread.php?tid=7174
http://www.sciencemadness.org/talk/viewthread.php?tid=7174&a...

IUPAC
Recommended Methods for the Purification of solvents & Tests for impurities:
Methanol & Ethanol
http://www.iupac.org/publications/pac/1985/pdf/5706x0855.pdf

.
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Amy Winehouse
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[*] posted on 3-4-2012 at 21:01


Thank you for the links franklyn, sorry i didn't utfse that well :\
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