Steve s - 20-2-2019 at 17:35
Hi All
Is it common practice to reuse the acetone used in a dry ice bath ?
I'll be using the ice bath to freeze flowers, a couple of flowers a day for about 10 days as part of dry ice demonstration. I gave it a try today and
noticed that the acetone seems to have been 'carbonated ?' 6 hours after use it is still pressurizing the HDPE bottle it is stored in. It also appears
to have lost a little of its pungency, it still seems to work ok as as a solvent (quickly dissolving a small piece of polystyrene).
I would like to be able to reuse the acetone not only from the point of cost but also this would save having to dispose of what would after 10 days be
a fairly large quantity of acetone.
I can't think of any reason why it can't be reused so will try using the recycled acetone again tomorrow but would appreciate any input/advice on the
long term effects repeated freezing/'carbonating' might have on the acetone.
happyfooddance - 20-2-2019 at 17:55
Because of exposure to the environment and its low temperature, your acetone has accumulated water by condensation.
Just be aware that after it gets a certain amount of water, it will start to freeze. Worse thing I could see happening is it cracking a container
(water expands when frozen).
You can dry acetone with Na, Mg, or Ca sulfates.
fusso - 20-2-2019 at 18:38
And maybe to distill it before reusing to remove any dissolved CO2 and impurities from the dry ice (if it has any)?
XeonTheMGPony - 20-2-2019 at 18:41
non food grade dry ice will have some traces of oil in it.
PirateDocBrown - 20-2-2019 at 19:19
Yep, I'd recycle it just as I recycle my wash acetone.
Vac distil, over anh. MgSO4, using a hot water bath.
Steve s - 21-2-2019 at 05:17
Thanks people
Just to clarify, would adding say 200g of a suitable anhydrous sulphate to the 2.5l container i'm storing the used acetone in absorb the water and
stay settled at the bottom of the container or would i still need to distill it. The venue doesn't have the facilities to set up a distillation set up
so i would need to take the acetone offsite to do a distillation.
I believe the dry ice is in fact food grade so probably doesn't contain any oil but i suspect the acetone might absorb a little oil from the flowers,
should i be concerned about this if i'm only using it for repeatedly freezing flowers ?
fusso - 21-2-2019 at 05:45
What kind of oil is in non food grade dry ice?
Tsjerk - 21-2-2019 at 07:28
Lubricant from the machine used to make it.
Sigmatropic - 21-2-2019 at 09:24
Where does dry ice come from? Considering how cheap it is I would guess it's a byproduct from an industrial process, perhaps water gas shift reactions
featuring in the Fischer-Tropsch, Haber-Bosch or production of methanol? Or is it simply all of the above?
Tsjerk - 21-2-2019 at 09:43
Factories producing ammonia from nitrogen and methane liquefy the produced carbon dioxide, the produced dioxide is in large excess compared to the dry
ice market.