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kazaa81
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ethanol purification by aluminum ?
hi,
I've heard that denaturated alcohol (ethanol) can
be purified (or maybe just precipitate its dye)
if aluminum turning are used?
anyone aware of that? I'm getting no
success while trying it.
thank you all
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12AX7
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No. If nothing else, you would need some acid or base to disrupt the aluminum's oxide layer anyway.
You might be thinking of calcium or other alkali metal turnings used to dry solvents such as ethanol (not the best as it slowly forms ethoxide with
such basic elements) and ethers.
Tim
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bio2
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I suppose one could form the ethoxide with amalgamated
Al then decompose that but there are other better ways
to dry or purify EtOH.
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vulture
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Ethanol is bound to contain some acetic acid, so that could start a reaction...
Is Aluminiumethoxide soluble in ethanol anyway? If not, the precipitate could indeed cause removal of the dye through some sort of flucculation
process.
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
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kazaa81
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| Quote: | Originally posted by vulture
If not, the precipitate could indeed cause removal of the dye through some sort of flucculation process. |
being just aluminum and ethanol, I think that's what is supposed to happen. Anyone got experience in this?
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S.C. Wack
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No one can be bothered to read Armarego and Perrin, which gives the outline and ref? Maybe it (both 4th and 5th eds.) never really existed and so
can't even be searched for, like most every other post here more than a couple months old.
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16MillionEyes
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So basically the whole procedure is add some aluminum turnings sit back and watch? How do you know (say) that the reaction has happened or not (any
specific color, thermal change etc)?
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kazaa81
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| Quote: | Originally posted by S.C. Wack
No one can be bothered to read Armarego and Perrin, which gives the outline and ref? Maybe it (both 4th and 5th eds.) never really existed and so
can't even be searched for, like most every other post here more than a couple months old. |
huh ?
as far as I know, the dye will precipitate on the bottom of the solution, leaving colorless alcohol.
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S.C. Wack
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That gives the reference on the purification of ethanol by Al!
Know what? There is no dye in any of several brands of denatured alcohol here!
How are we supposed to know how to purify the alcohol in your hands?
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kazaa81
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| Quote: | Originally posted by S.C. Wack
That gives the reference on the purification of ethanol by Al!
Know what? There is no dye in any of several brands of denatured alcohol here!
How are we supposed to know how to purify the alcohol in your hands? |
Do you know how much is for a copy of Armarego and Perrin latest edition?
Damn, no dye? Then who knows what's solved in there...That's another thing  to
keep in mind while disinfecting wounds in hydrogen peroxyde shortage 
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bio2
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..."Is Aluminiumethoxide soluble in ethanol anyway?"........
I don't know but I do know that the methoxide is not very soluble in MeOH and precipitates out.
Easy to decompose also just a little water and some heat.
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indigofuzzy
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Ok, if I'm reading right, we're trying to purify denatured alcohol? Where I live, denatured alcohol is ethanol mixed with methanol to make it
unsuitable for drinking. Other localities or nations may vary.... The downside is, I'm not 100% sure how to get the methanol out. I don't know if they
form an azeotrope that would make distillation not work.
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kazaa81
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| Quote: | Originally posted by indigofuzzy
Ok, if I'm reading right, we're trying to purify denatured alcohol? Where I live, denatured alcohol is ethanol mixed with methanol to make it
unsuitable for drinking. Other localities or nations may vary.... The downside is, I'm not 100% sure how to get the methanol out. I don't know if they
form an azeotrope that would make distillation not work. |
read carefully  ...we're talking about a specific method used in alcohol
purification, the one which uses aluminum turnings to precipitate dyes out of solution.
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S.C. Wack
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| Quote: | Originally posted by kazaa81
Do you know how much is for a copy of Armarego and Perrin latest edition? |
That would be the 5th. Yes. Free.
You might want to find out what is in your alcohol and what you want it for. If you ask random questions you will get random answers, like use
aluminum.
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kazaa81
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| Quote: | Originally posted by S.C. Wack
| Quote: | Originally posted by kazaa81
Do you know how much is for a copy of Armarego and Perrin latest edition? |
That would be the 5th. Yes. Free.
You might want to find out what is in your alcohol and what you want it for. If you ask random questions you will get random answers, like use
aluminum. |
Where can I get one? Thank you for your fast reply.
Seems like in EU, these denaturants are used :
to every 100 liters of EtOH are added:
Tiophene: 125 g.
Denatonium benzoate: 0,8 g.
25% solution w/w of C.I. Reactive Red 24 (red dye): 3 g.
Methyl ketone 2 liters (I think that's MEK, 2-butanone).
The denaturing power of denatonium benzoate is always astonishing 
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not_important
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| Quote: | Originally posted by indigofuzzy
Ok, if I'm reading right, we're trying to purify denatured alcohol? Where I live, denatured alcohol is ethanol mixed with methanol to make it
unsuitable for drinking. Other localities or nations may vary.... The downside is, I'm not 100% sure how to get the methanol out. I don't know if they
form an azeotrope that would make distillation not work. |
No azeotrope, just difficult to separate because of the relative closeness of the boiling points of methanol and ethanol or the ethanol-water
azeotrope. Most people don't have the equipment to do the fractional distillation required, certainly not to the point of completely removing the
methanol.
Dyes and other large molecules are fairly easy to remove by distillation, some of the hydrocarbon additives can be difficult because of close boiling
points or formation of azeotropes.
While absorbing the dyes onto Al(OH)3 might work, you're still likely going to need to do a distillation, in which as the Al(OH)3 might just be extra
work unless it is a product of reacting aluminium with the water with the intent of drying the alcohol.
Is "Tiophene" actually thiophene? Thiophene forms an azeotrope with ethanol, and generally needs to be removed through chemical reaction.
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kazaa81
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| Quote: | Originally posted by not_important
Dyes and other large molecules are fairly easy to remove by distillation, some of the hydrocarbon additives can be difficult because of close boiling
points or formation of azeotropes.
While absorbing the dyes onto Al(OH)3 might work, you're still likely going to need to do a distillation, in which as the Al(OH)3 might just be extra
work unless it is a product of reacting aluminium with the water with the intent of drying the alcohol.
Is "Tiophene" actually thiophene? Thiophene forms an azeotrope with ethanol, and generally needs to be removed through chemical reaction.
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I once observed that boric acid did "bleach out" EtOH dye, and
yes I think it is Thiophene, not tiophene.
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woelen
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In the Netherlands, we have something called 'spiritus', and it always has a deep blue color and a terrible smell. I'm not sure what is in it. The
bottle only says that it contains 85% ethanol, but the other ingredients are not listed. Anyone here, who knows this blue 'spiritus' and what is in
it?
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vulture
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I've distilled the stuff over a vigreux column and although the colour is gone, the smell stays, even after a second distillation.
It has a somewhat mint like smell, but very intense and almost unbearable.
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
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not_important
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| Quote: | Originally posted by woelen
In the Netherlands, we have something called 'spiritus', and it always has a deep blue color and a terrible smell. I'm not sure what is in it. The
bottle only says that it contains 85% ethanol, but the other ingredients are not listed. Anyone here, who knows this blue 'spiritus' and what is in
it? |
this?
http://nl.wikipedia.org/wiki/Spiritus_%28alcohol%29
85% ethanol,
10% water,
3% methanol,
1% acetone
1% pyridine - stinks
blue dye.
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16MillionEyes
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The rite aid rubbing alcohol lists:
70% Ethyl Alcohol (by volume)
Acetone
Denatonium benzoate (I see it's also present for the alcohol Kazaa posted, any particular purpose known other than to avoid consumption?)
Methyl Isobutyl ketone
Purified water
If you ask me this seems like a hectic job to purify. Any ideas?
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16MillionEyes
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Never mind about the Denatonium. I found the answer and possibly the answer for what someone else asked about a stinking smell:
"To help prevent this, Denatonium is often added to give the substance an extremely bitter flavor. Substances such as Pyridine help to give the
mixture an unpleasant odor, and emetic (vomiting) agents such as syrup of ipecac may also be included."
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The_Davster
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Mine:
95% EtOH
camphor
diethylbenzyl benzoate
diethyl phthalate
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kazaa81
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I left denaturated ethanol (pink-purple) with some
aluminum foil turnings for a week in a vial.
Here are two pictures about what happened :
with aluminum still in
without aluminum
So it seems like the dye was precipitated in some way
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16MillionEyes
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Yeah, it's clear enough there's a formation of a precipitate. I'm guessing that's only getting rid of the dye you've been talking about.
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