MKSStal
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Methyl acetate and acetone separation
I have a solvent containing both methyl acetate and acetone. They have very similar boiling points and what is more form an azeotrope with close b.p.
Acetone is miscible with water and AcOMe is about 25g/100g H2O so it want help very much as acetone will dissolve in methyl acetate layer. Any ideas
how to separate those two?
[Edited on 26-12-2016 by MKSStal]
[Edited on 26-12-2016 by MKSStal]
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Metacelsus
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You could try hydrolyzing the methyl acetate, and then separating the acetone from the methanol and acetic acid.
Other than that, I can't think of any good way to separate them.
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Tsjerk
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4A sieves absorp aceton but not methyl acetate.
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Cryolite.
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4A sieves also induce aldol-type polymerization of acetone...
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Tsjerk
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Does it when the acetone itself is absorpted? Can acetone condense when bound to sieves? For that to happen there should be an binding preference for
water over acetone.
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JJay
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I think you could use sodium bisulfite to bind the acetone, distill off the methyl acetate, use alkali to free the acetone, and distill.
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MKSStal
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Do you think that standing over sodium bisulfite even for long time with some shaking might do the work? I don't want to add to the mixture of
solvents: methyl, ethyl and butyl acetates, acetone and methyl ethyl ketone another solvents like water and ethanol.
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Tsjerk
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Bisulfite has to be dissolved to form adducts, if sodium bisulfite is soluble in your system, I'm pretty sure the acetone adduct will also be soluble,
I don't know if these adducts are heat stable enough to survive distillation.
Edit: a bisulfite solution in water just concentrated enough to allow the acetone adduct to fully dissolve in the water could possibly take up the
acetone while salting out the methyl acetate. Or they form one big mixture, also possible.
[Edited on 27-12-2016 by Tsjerk]
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JJay
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You don't have to add any alcohol to form the adducts; just water and sodium bisulfite should be enough.
I don't know how heat stable the acetone-sodium bisulfite adduct is, but you could vacuum distill the acetone if necessary. Right?
[Edited on 28-12-2016 by JJay]
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Tsjerk
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I wonder what the vapour pressure is of acetone above the acetone bisulfite, if any. If there is none vacuum distillation should work.
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JJay
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One vendor reports acetone-sodium bisulfite adduct's melting point as 300 C. *shrug*
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Tsjerk
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OK, then JJay's proposed method should work.
Methyl acetate forms an azeotrope with water at basically its boiling point (56.1 - 57 degrees respectivally) at 95% methyl acetate, but you can dry
the methyl acetate afterwards.
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