Sciencemadness Discussion Board

Diethyl Ether from Denatured alcohol?

DIBALL - 22-4-2017 at 13:02

Since pure ethanol is quite expensive and denatured alcohol is only 1/10th of the price, I wanted to know, if there are any problems with the other added contents?
Where I live, MEK, methanol and/or denatonium are usually added to the ethanol.

I dried the alcohol with magnesium sulfate, but it looks like the product is already really pure since I didn´t need a lot.

Next I wanted to let it react with conc. sulfuric acid and then distill it. So if there are any side products, the distillation should get rid of them, or do I miss anything important?

JJay - 22-4-2017 at 13:05

Removing the methanol is an enormous amount of work, although in my opinion it is legal if you're just making ether. If you can, get a variety that doesn't contain methanol.

DIBALL - 22-4-2017 at 13:41

Is there an easy way to find out, if my product contains methanol? On the bottle is only written, that it is denatured ...

PirateDocBrown - 22-4-2017 at 14:05

If you etherate an ethanol-methanol mixture, and carry off the product by distillation, the side products will escape into the gas phase.

Product BP

Dimethyl ether -24
Methoxyethane 7
Diethyl ether 35

Do an inert gas sparge at RT, if what left might disturb you.

JJay - 22-4-2017 at 14:50

Some denatured alcohol is actually more than 50% methanol and will produce very little diethyl ether if used directly.

JJay - 22-4-2017 at 16:42

Quote: Originally posted by DIBALL  
Is there an easy way to find out, if my product contains methanol? On the bottle is only written, that it is denatured ...


It usually won't contain exact figures, but the SDS can give you some idea of what is in your denatured alcohol.

DIBALL - 22-4-2017 at 17:05

Okay I just found the safety sheet and it says that it contains 3 things: ethanol, MEK and water.

Ethanol is 95%
MEK 1%
and the rest is water

MEK shouldn´t react with the sulfuric acid or ethanol? Or could the sulfuric acid act as a catalyst for a reaction between ethanol and MEK?
Since MEK and Diethyl Ether have such different boiling points, it should be easy to separate them

clearly_not_atara - 22-4-2017 at 17:08

Quote: Originally posted by JJay  
Some denatured alcohol is actually more than 50% methanol and will produce very little diethyl ether if used directly.
I think they stopped doing this most places because it kills people.

JJay - 22-4-2017 at 17:20

Quote: Originally posted by clearly_not_atara  
Quote: Originally posted by JJay  
Some denatured alcohol is actually more than 50% methanol and will produce very little diethyl ether if used directly.
I think they stopped doing this most places because it kills people.


The Klean Strip "fuel" alcohol contains an outrageous amount of methanol: https://www.korellis.com/wordpress/wp-content/uploads/2016/0...

I assume it tastes terrible, but I haven't tried any

anewsoul - 22-4-2017 at 17:30

And I've been using this Klean Strip alcohol thinking it was reasonably pure ethanol.... well forget that. Thanks for that information.

Morgan - 22-4-2017 at 17:43

Klean Strip Denatured Alcohol
Ethyl alcohol 30.0 -50.0 %
Methanol 40.0 -60.0 %
Additional Chemical Specific percentage of composition is being withheld as a trade secret.
If methanol was added at a possible 40%, wouldn't the ethanol content have to be 60% or are there other secret ingredients?
https://www.korellis.com/wordpress/wp-content/uploads/2016/0...

Klean Strip Green Denatured Alcohol
Ethyl alcohol 80.0 -90.0 %
Methanol < 5.0 %
Acetic acid, ethyl ester {Ethyl acetate} 1.5 %
Specific percentage of composition is being withheld as a trade secret.
http://www.kleanstrip.com/uploads/documents/QKGA75003_SDS-16...



[Edited on 23-4-2017 by Morgan]

JJay - 22-4-2017 at 19:06

Though I don't suggest this, I've actually distilled it before. It contains a little water, as well as something that isn't miscible with water. I think someone suggested it might be MIBK. But Klean Strip "fuel" denatured alcohol certainly contains a *lot* of methanol.

PirateDocBrown - 22-4-2017 at 19:53

Yes, if you are gonna make ether, use the "Green" stuff. I clean it up and use it for lab ethanol. Doug's Lab has a very good video doing just that.

Better still, for ether just purify starter fluid.

alking - 23-4-2017 at 10:17

Ketones will tautomerize with strong acids, but that shouldn't really matter as it's no more or less of a contaminant than the ketone. If you cannot fractionally distill out the ketone, or the ether from the ketone, you can react the alcohol with a base which will cause the ketone to polymerize. From there you can distill off the alcohol to recover it, leaving the polyketone behind, or you can neutralize the base and form the ether directly as I don't think there would be any side reactions, however you wouldn't be sure the ketone was fully polymerized that way.

I have tried to use that green stuff before and for me there did not seem to be close to what they claimed, it likely varies per locale even though they share an sds. I refluxed it 3x in NaOH and distilled it and each time some of this foul smelling substance remained, I'm not sure what it could have been. It was supposed to be 95% EtOH with a small amount of ethyl acetate, maybe MiBK, and <1% unlisted denaturents. However it seemed at least 10% of it would polymerize to some almost black product and I gave up as after the third trial it still would keep occurring. After all that work it's cheaper just to distill vodka or something or just buy some lab grade.

DrMethyl - 4-5-2017 at 07:54

Quote: Originally posted by DIBALL  
Okay I just found the safety sheet and it says that it contains 3 things: ethanol, MEK and water.

Ethanol is 95%
MEK 1%
and the rest is water

MEK shouldn´t react with the sulfuric acid or ethanol? Or could the sulfuric acid act as a catalyst for a reaction between ethanol and MEK?
Since MEK and Diethyl Ether have such different boiling points, it should be easy to separate them


Hi, if there is 4% or more water, you can predry with MgSO4 or Na2SO4 anhydrous.

Its a good point there is only 1% MEK, it wont fuck up your reaction.

Booze - 6-5-2017 at 10:38

There is denatonium in the stuff where I live too. Is it possible to boil it down completely to get denatonium benzoate? I wanna use it for pranks