Sciencemadness Discussion Board

Separation of acetone and THF

Crypto - 1-12-2013 at 07:33

Any ideas on separating these two solvents? Boiling points for acetone and THF respectively are 56°C and 65°C. They form an azeotrope.

deltaH - 1-12-2013 at 08:33

You can use extractive distillation to 'break' the azeotrope. This system has been studied in this paper:

Shenfeng Yuan, et. al., Separation of acetone–tetrahydrofuran azeotropic mixture by continuous extractive distillation, Journal of Chemical Technology and Biotechnology, 88(8), pp. 1523–1528.

http://onlinelibrary.wiley.com/doi/10.1002/jctb.3997/abstrac...

Apparently dibutyl ether is a suitable extractive solvent for this system.

I don't have access to this paper, so request in the 'references' section if needed.

Hope that helps.

[Edited on 1-12-2013 by deltaH]

DJF90 - 1-12-2013 at 10:26

Do you wish to recover both components in a useable form?

UnintentionalChaos - 1-12-2013 at 10:35

I would suggest looking at ketone bisulfite adducts...

BlackDragon2712 - 1-12-2013 at 11:07

what about reacting the acetone with an hydroxide and then distilling. acetone would enter to aldol condensation to give diacetone alcohol with a bp of 160 C° so separation would be easy.

http://www.orgsyn.org/demo.aspx?prep=cv1p0199

Asepsis - 1-12-2013 at 17:46

I agree with UnintentionalChaos. Making the bisulfite adduct is easy and precipitates out the ketone for simple filtration/separation.
I'd advise against reacting the ketone with base as you'll get a host of sticky gooey compounds, not just diacetone alcohol.

BlackDragon2712 - 1-12-2013 at 18:20

still, the THF would be able to be distilled but I was just giving an idea, I agree with UC, bisulfite adduct would be something worth to try. Also reacting acetone with barium hydroxide would be something more complex so yeah, again your best option is the already mentioned