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Author: Subject: Puryfiing 99% denatured alcohol
Schleimsäure
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[*] posted on 9-7-2021 at 09:07
Puryfiing 99% denatured alcohol


So got myself another 2,5l of denatured 99% Ethanol.

New is, the alcohol thistime is not only denatured with 1% MEK and a few ppm Bitrex.
Bitrex can be get rid of with simple destillation. MEK with Hydroxylamine.

But thistime it reads also 1% IPA (which makes 101% but anyway).

Boiling point of IPA is much too close to Ethanol.

So no chance of getting rid of the IPA, I guess?
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[*] posted on 9-7-2021 at 10:26


Ah the damn new EU laws... yeah, mucic acid, I stumbled upon this new adulterant too :mad:

They are even in the cheaper spiritus brands now... I loved to use the good old AHK spiritus in the clear bottle with the green cap... besides it getting almost twice as expensive very recently, now they added that crappy IPA to it.
I don't know either.

Just wanted to express my frustration about this new law as well.
PS: I remove MEK usually by refluxing with some NaOH, and then distilling the ethanol off, as the MEK will selfcondense in an aldol to a much higher boiling compound.
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Tsjerk
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[*] posted on 9-7-2021 at 11:46


What do you need the IPA seperated for? It should be fine for most purposes.
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[*] posted on 9-7-2021 at 11:58


Not a direct answer to the OP question, but bitrex/denatonium can be removed easily by treatment with an acidic ion exchange resin such as polystyrene sulfonate. It's cheap, fast and effective. It works because denatonium is a quaternary ammonium compound. Also, mucic acid should be just as easily to get rid of using a similar basic ion exchange resin.

[Edited on 10-7-2021 by stamasd]




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[*] posted on 10-7-2021 at 01:59


Quote: Originally posted by karlos³  
mucic acid, I stumbled upon this new adulterant too


Wait, what? I can't find any references to that that, and it's supposed to be insoluble in alcohol. Either way it should be easy to remove by distillation.

[Edited on 10-7-21 by Fulmen]




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[*] posted on 10-7-2021 at 02:50


The new adulterant I meant is the IPA, which
was formerly not in denat. alcohol here, it is now in use EU-wide.
Bitrex is easily removed via distillation indeed.

E: with "mucic acid", I spoke to the user Schleimsäure, which is the german word for mucic acid.
It is not in denatured alcohol :D
Sorry for the confusion :P

[Edited on 10-7-2021 by karlos³]
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[*] posted on 10-7-2021 at 03:32


:D



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[*] posted on 10-7-2021 at 07:40


Quote: Originally posted by Tsjerk  
What do you need the IPA seperated for? It should be fine for most purposes.


Sometimes you need pure EtOH. Also isn't it neat to have pure reagents?
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[*] posted on 10-7-2021 at 07:42


Quote: Originally posted by karlos³  
Ah the damn new EU laws... yeah, mucic acid, I stumbled upon this new adulterant too :mad:

They are even in the cheaper spiritus brands now... I loved to use the good old AHK spiritus in the clear bottle with the green cap... besides it getting almost twice as expensive very recently, now they added that crappy IPA to it.
I don't know either.

Just wanted to express my frustration about this new law as well.
PS: I remove MEK usually by refluxing with some NaOH, and then distilling the ethanol off, as the MEK will selfcondense in an aldol to a much higher boiling compound.


Ja, didn't know it was new "EU law". Concerning MEK I used once also some NaOH. But hydroxylamine is the safer choice as far as I know, making the oxime of the MEK.
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[*] posted on 10-7-2021 at 07:47


Found a very old source. They should have some "old stock".

https://www.aurelio-online.com/epages/61694983.sf/de_DE/?Obj...


5l for 19 EUR is also kind of ok in price.

EDIT: Spoke too soon, also with IPA already.

[Edited on 10-7-2021 by Schleimsäure]
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[*] posted on 10-7-2021 at 16:44


Quote: Originally posted by Schleimsäure  

Sometimes you need pure EtOH. Also isn't it neat to have pure reagents?


I have been looking around for ways to selectively oxidize secondary alcohols, but couldn't find much useful.
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[*] posted on 10-7-2021 at 18:14


Most probably not worth the effort. In case you will have to pay the price for absolute ETOH, I guess.
But you are right oc, for many purposes den. EtOH is sufficient.

I think in France MeOH is still used to denature. That would be not suitable for certain fragrances things for example.
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[*] posted on 11-7-2021 at 04:39


It's weird when you think about it that they would use IPA as a denaturant. The purpose of the denaturants is to prevent people from drinking the alcohol and IPA is not much of a deterrent in that regard. It does not add any weird tastes, nor is it overly toxic.



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[*] posted on 11-7-2021 at 06:38


It does make any illicit liquor produced with it easily detectable.
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[*] posted on 11-7-2021 at 13:27


Along the lines of this thread, I feel like I got cheated out of a good organic lab experience because of covid. For my own purposes, I have just over a gallon of 45-55% ethanol denatured alcohol with the other portion being methanol. Is a methanol denatured alcohol solution really that difficult to separate? I've read a source say they azeotrope and many others not make mention of it. Wouldn't a good fractioning setup work well?



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[*] posted on 12-7-2021 at 20:51


What reactions would be such that 1% of IPA would be detrimental to their outcome? Just interested.

My common source for cheap otc EtOH has been contaminated with all other nasties along with MEK, but has been decent for all of my uses so far, so haven't complained. My go-to has been to stir it for few hours with 2-3% NaOH during which it turns tar black and then distill off the ethanol.

50% Methanol ethanol mix would seem somewhat uneconomical to separate, unless you have over 1m active reflux column, and even then most will consider it absolutely unsuitable for consumption of any sort. Reason methanol is verboten in EU is because alcoholics will consume cheap substitute alcohols due to high tax, and may not be too precise what they sip especially under influence. I actually think it's a good thing to keep it off as a denaturant, because it's purpose is to de-nature it to unpotable consistency so that anyone attempting to drink it will desirably puke it up at once, not to poison it by way that tastes exactly like the real thing but will burn off your eyes first and then kill you.

[Edited on 13-7-2021 by Fyndium]
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[*] posted on 12-7-2021 at 22:20


Quote: Originally posted by stamasd  
It's weird when you think about it that they would use IPA as a denaturant. The purpose of the denaturants is to prevent people from drinking the alcohol and IPA is not much of a deterrent in that regard. It does not add any weird tastes, nor is it overly toxic.


It also serves to remove water as a ternary azeotrope to give nice, dry denatured ethanol.

I used to get denatured ethanol that was 5% isopropanol, but fairly anhydrous.
This was in the USA, and the isopropanol was the sole denaturant.

I suppose you could rid it of isopropanol by adding water and boiling off that ternary azeotrope, but then it would need drying if you needed it anhydrous.




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[*] posted on 13-7-2021 at 06:38


I think IPA is a pain to separate from ethanol. I can think of no conventional method that does it easily with typical hobby equipment. (That rules out stuff like rotating columns with hundreds of plates etc) I guess a large column with a huge reflux (perhaps more than once) could do the job very slowly (perhaps multiple very long distillastions). You're probably faster off making acetates, separating them and hydrolizing followed by distillation or whatever other reactions you may like.

Extractive distillation seems one method that can be used industrially but it is not very suitable for a hobby lab and batch jobs. Even with this method you may still need very large number of plates like 50 like estimated here https://scholarworks.montana.edu/xmlui/bitstream/handle/1/62...

Luckily I have available a windshield washing fluid concentrate that has only 1% MEK in it along with some easy to distill off surfactants, parfume and about 20-25% water. Dirt cheap too, something like €15 per 10 liters. Takes a while to distill a canister due to lots of water.

Fortunately slight impurities won't matter often. Even if you use it as a reagent, you still get only 1% of the wrong stuff. You rarely get 99% yield anyway. Isopropanol rarely destroys reactions where ethanol is ok.

If you really need ethanol without isopropanol, you are probably better off starting with something without IPA in it in the first place. IPA free drinkable alcohol is easily available but can cost quite a bit due to taxing.
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[*] posted on 13-7-2021 at 08:09


Quote: Originally posted by Tsjerk  
It does make any illicit liquor produced with it easily detectable.

Yeah, I agree, that might have been their point with this addition.
Up until around ~1,5 years ago, I could distill the denat. ethanol (AHK Spiritus) that was sold for I think around 2,40€ back then, after refluxing with some sodium hydroxide, and after redistillation it smelled as clean as vodka.
A taste test confirmed cleanest ethanol as well :o :P

It was a good source for pure ethanol, and I can imagine some people with the facilities would be tempted to turn the cheap denat ethanol into taxed drinking ethanol(of which the denat. EtOH has merely 5% of its worth, before the recent inflation, making the whole process very worthy if you have huge distillation equipment for some reason).

Now that stuff stinks after IPA after the distillation, but of course it is still good to use it for almost everything.
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[*] posted on 13-7-2021 at 09:07


In the end, the purpose of denaturing alcohol is indeed not to make it undrinkable, the goal is to not lose taxes.
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[*] posted on 13-7-2021 at 09:50


Yes, I would even think that is indeed one of the largest worries the states have.
Considered that the liquor tax is among petrol and tobacco taxes resulting in the highest incomes.

I would want to protect that source too, if it fills my wallet.
its was a bigger problem in the eastern european states, but since this is now enacted EU-wide.... we'll see.

Also, the denatured ethanol got much more expensive, is this the same in other EU countries?
It suddenly increased about 40% for the good denat. EtOH I usually buy(AHK Spiritus, as said), now it costs almost 4€.
And that can definitely not be explained with the recent addition of IPA!
Either its ripoff or inflation.
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[*] posted on 13-7-2021 at 09:50


If you want it really clean, have a time and will to distill it then maybe a sugar and turbo yeast are good option? Needs some time for the process and purification but in the end can be really clean
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[*] posted on 13-7-2021 at 10:26


Yeah if its for the production of drinkable/clean ethanol, I heard good things from a friend who makes, what was it called... "poitin" I think?
True *** local whiskey is a clear liquid, i've been told.
A friend from europe told me that, local declaration... eh... maybe it was another name from another country? :P
But its just sugar, turbo yeast, distillation and no liquor tax.

Do swedes and danes do that too?
They brew to avoid the state liquor shops, thats known, but do they also moonshine?
And if, how do they call it?

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[*] posted on 13-7-2021 at 11:44


I heard moonshining is big in Scandinavian countries, I don't know how they call the process, but the liquor is called snaps. They use to bring their own snaps to parties as buying alcoholic drinks for many guests becomes expensive real fast.
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[*] posted on 13-7-2021 at 11:53


It's a bit of a dying art most places I think, but there are always some that keep the tradition going.



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