ATOT chemists: chemical separation question

[Mark R]

Is there a practical way to separate a mixture of ethanol and butanone?

Distillation isn't an option with this pair, as the two have near identical boiling points and vapor pressure profiles.

Crystallization would be impractical due to the very low temperatures (below dry ice) required.

Could you reduce out the butanone with a suitable reducing agent, and then separate the ethanol/butanol mixture? Is the yield of this reaction adequate?

 

[Brigandier]

It seems like the only way would be to exploit the more reactive nature of ethanol.

/Made lot of garage booze out of windshield wiper fluid.
What do you want more of, butanone or ethanol?

 

[linuxboy]

Yes, use extractive distillation and a separation solvent. Choose the separation solvent you want depending on whether you want to recover ethanol or butanone at the top. EG, DMSO mixed in to recover butanone on top.

 

[zinfamous]

the body readily metabolizes ethanol, so drink your mixture and separate the butanone from your piss?

:hmm:

 

[Mark R]

Out of a 97% ethanol/3% butanone mixture, I'd like the ethanol.

 

[Howard]

How much do you have?

 

[Howard]

http://www.google.com/patents/US5453166

 

[Gibsons]

Howard looks to have the answer, but let me throw this out: If you put it in a really strong base or maybe sodium, can you deprotonate the ethanol (make sodium ethoxide), and remove the butanol with something like hexane? Take the water fraction and add acid to get ethanol back.

This might be really dumb, too long since I took ochem. 🙁

 

[Mark R]

How much do you have?

About 1000 gallons.

f you put it in a really strong base or maybe sodium, can you deprotonate the ethanol (make sodium ethoxide)

I was thinking of the opposite. Whack in some sodium borohydride, and reduce the butanone to 2-butanol. Then you'll get an excellent separation with simple distillation.

The ethanol will come out on top, so it should be further purified of any other undesirables.

No idea if this would work though.

 

[zinfamous]

About 1000 gallons.

:hmm:


....are you storing this mixture in an unmarked tank buried in a remote spot out in the Sonoran Desert, vicinity of New Mexico, perhaps under some train tracks?

just curious.

 

[uclaLabrat]

About 1000 gallons.



I was thinking of the opposite. Whack in some sodium borohydride, and reduce the butanone to 2-butanol. Then you'll get an excellent separation with simple distillation.

The ethanol will come out on top, so it should be further purified of any other undesirables.

No idea if this would work though.

That would probably work fine. My first thought was add in something else and do an azeotropic distillation to isolate either component (Ethanol and MEK azeotrope with water, but the differences in boiling ranges aren't that great at 68 deg to 74 deg). That was just a quick google search, you might be able to find a better solvent pair.

Edit: Alternatively, you could add some hydroxylamine and make the oxime, that would be one hell of an easy separation 😀