Sciencemadness Discussion Board
Not logged in [Login - Register]
Go To Bottom

Printable Version  
Author: Subject: Methyl acetate and acetone separation
MKSStal
Harmless
*




Posts: 17
Registered: 4-5-2015
Member Is Offline


[*] posted on 26-12-2016 at 02:41
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]
View user's profile View All Posts By User
Metacelsus
International Hazard
*****




Posts: 1900
Registered: 26-12-2012
Location: Minneapolis, Minnesota, USA
Member Is Offline

Mood: Double, double, toil and trouble

[*] posted on 26-12-2016 at 07:33


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.




As below, so above.
View user's profile View All Posts By User
Tsjerk
International Hazard
*****




Posts: 547
Registered: 20-4-2005
Location: Germany
Member Is Offline


[*] posted on 26-12-2016 at 07:38


4A sieves absorp aceton but not methyl acetate.
View user's profile View All Posts By User
Cryolite.
Hazard to Others
***




Posts: 153
Registered: 28-6-2016
Location: CA
Member Is Offline


[*] posted on 26-12-2016 at 13:58


4A sieves also induce aldol-type polymerization of acetone...
View user's profile View All Posts By User
Tsjerk
International Hazard
*****




Posts: 547
Registered: 20-4-2005
Location: Germany
Member Is Offline


[*] posted on 26-12-2016 at 23:29


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.
View user's profile View All Posts By User
JJay
International Hazard
*****




Posts: 2230
Registered: 15-10-2015
Location: the sassafras grove
Member Is Offline

Mood: encrypted

[*] posted on 27-12-2016 at 02:17


I think you could use sodium bisulfite to bind the acetone, distill off the methyl acetate, use alkali to free the acetone, and distill.



Check out my nascent YouTube channel: Extreme Red Cabbage
View user's profile View All Posts By User
MKSStal
Harmless
*




Posts: 17
Registered: 4-5-2015
Member Is Offline


[*] posted on 27-12-2016 at 11:03


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.
View user's profile View All Posts By User
Tsjerk
International Hazard
*****




Posts: 547
Registered: 20-4-2005
Location: Germany
Member Is Offline


[*] posted on 27-12-2016 at 13:07


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]
View user's profile View All Posts By User
JJay
International Hazard
*****




Posts: 2230
Registered: 15-10-2015
Location: the sassafras grove
Member Is Offline

Mood: encrypted

[*] posted on 27-12-2016 at 13:38


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]




Check out my nascent YouTube channel: Extreme Red Cabbage
View user's profile View All Posts By User
Tsjerk
International Hazard
*****




Posts: 547
Registered: 20-4-2005
Location: Germany
Member Is Offline


[*] posted on 27-12-2016 at 22:25


I wonder what the vapour pressure is of acetone above the acetone bisulfite, if any. If there is none vacuum distillation should work.
View user's profile View All Posts By User
JJay
International Hazard
*****




Posts: 2230
Registered: 15-10-2015
Location: the sassafras grove
Member Is Offline

Mood: encrypted

[*] posted on 28-12-2016 at 02:35


One vendor reports acetone-sodium bisulfite adduct's melting point as 300 C. *shrug*



Check out my nascent YouTube channel: Extreme Red Cabbage
View user's profile View All Posts By User
Tsjerk
International Hazard
*****




Posts: 547
Registered: 20-4-2005
Location: Germany
Member Is Offline


[*] posted on 28-12-2016 at 07:20


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.
View user's profile View All Posts By User

  Go To Top