X-321
Harmless
Posts: 3
Registered: 24-1-2007
Member Is Offline
Mood: No Mood
|
|
DMSO separation
Hi everybody,
How could I separate ethyleneglycol from DMSO?
EG bp = 197.3 ºC
DMSO bp = 189 ºC
Thank you.
[Edited on 24-1-2007 by X-321]
|
|
|
Ozone
International Hazard
Posts: 1269
Registered: 28-7-2005
Location: Good Olde USA
Member Is Offline
Mood: Integrated
|
|
Other relevant physical property:
The melting point for DMSO is 18.5°C and Ethylene glycol melts at -12.9°C.
Give that a shot,
O3
-Anyone who never made a mistake never tried anything new.
--Albert Einstein
|
|
|
X-321
Harmless
Posts: 3
Registered: 24-1-2007
Member Is Offline
Mood: No Mood
|
|
Thank you, O3.
|
|
|
BromicAcid
International Hazard
Posts: 3227
Registered: 13-7-2003
Location: Wisconsin
Member Is Offline
Mood: Rock n' Roll
|
|
The boiling points are fairly close to separation by boiling might be very difficult. However there is an azeotrope between ethylene glycol and
toluene or xylene. This boils lower than ethylene glycol itself, somewhere in the neighborhood of 120ish. This might work to get ride of your
ethylene glycol from the mixture.
|
|
|
Ozone
International Hazard
Posts: 1269
Registered: 28-7-2005
Location: Good Olde USA
Member Is Offline
Mood: Integrated
|
|
o-xylene, I think. You will also chase out whatever water you may have (and you *will* have some in this mixture, unless you have distilled it with a
Dean-Starke trap onto molecular sieves). But--Have you ever smelled boiling DMSO, expecially if a drop gets into your heating mantle. Good stuff.
Some Data:
Toluene chaser: 110.1°C, but 97.7% of the azeotrope is toluene
o-xylene chaser: 135.7°C, but 93.1% will be xylene.
Following this, It looks like tedious removal of solvent.
Best of luck,
O3
-Anyone who never made a mistake never tried anything new.
--Albert Einstein
|
|
|
BromicAcid
International Hazard
Posts: 3227
Registered: 13-7-2003
Location: Wisconsin
Member Is Offline
Mood: Rock n' Roll
|
|
Maybe salt it out? DMSO dissolves a number of ionics fairly well and I don't think ethylene glycol compares. Might result in a phase separation and a
simple distillation might give the product?
|
|
|
Ozone
International Hazard
Posts: 1269
Registered: 28-7-2005
Location: Good Olde USA
Member Is Offline
Mood: Integrated
|
|
@X-321, what proportion of each is present in your mixture, viz. how quantitative does the separation have to be?
O3
-Anyone who never made a mistake never tried anything new.
--Albert Einstein
|
|
|
X-321
Harmless
Posts: 3
Registered: 24-1-2007
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by Ozone
@X-321, what proportion of each is present in your mixture, viz. how quantitative does the separation have to be?
O3 |
1. The molar proportion DMSO/EG = 20/1.
2. Technical grade for EG is ok and the DMSO doesn´t mater since it would be reused many times for the same purpose.
|
|
|
unionised
International Hazard
Posts: 5103
Registered: 1-11-2003
Location: UK
Member Is Offline
Mood: No Mood
|
|
At that ratio freezing the stuff and pouring off the EG (with some loss of DMSO) will work quite nicely. It's also a way to remove water etc from
DMSO, Acetic acid etc
|
|
|
Ozone
International Hazard
Posts: 1269
Registered: 28-7-2005
Location: Good Olde USA
Member Is Offline
Mood: Integrated
|
|
That's where I was going with the Tm's  . I have not used this method with
ethylene glycol, but have used it to remove, as you say, just about everything else (although, to dry, I still prefer to re-distill over mol sieves
afterwards).
Cheers,
O3
Oh, this can easily be done with an ice-salt bath and a thermometer; no worries.
[Edited on 26-1-2007 by Ozone]
-Anyone who never made a mistake never tried anything new.
--Albert Einstein
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
