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Author: Subject: Freezing ethanol with liquid carbon dioxide?
symboom
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smile.gif posted on 4-4-2017 at 20:59
Freezing ethanol with liquid carbon dioxide?


Temperature needed 182°C is just below boiling point
Cascading done by dry ice and acetone
Drops temperature to -75C if liquid carbon dioxide is released in cooling coils inside a dry ice bath with acetone then poured into a ethanol

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j_sum1
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[*] posted on 5-4-2017 at 00:00


Confused by your post symboom. Not sure what the 182°C is for. Liquid CO2 implies that you have it under pressure.

Ethanol freezes at -114°C.
Dry ice and acetone will get you down to -78°C.
To get lower than that you need liquid nitrogen.

Any reason why you need solid ethanol?
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DrP
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[*] posted on 5-4-2017 at 04:55


We used to use IPA with dry ice - it goes quite viscous and makes a good connection with the glassware. Does acetone thicken as much at that temp?



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XeonTheMGPony
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[*] posted on 5-4-2017 at 05:06


Nope Acetone stays nice and runny.

To freeze solid ethanol LN2 or good sodding luck! Some friends visiting one complained my alcohol was warm, so I dropped it in some LN2 and told them to let it warm up befor touching it! LOL their expression was priceless! (I didn't care if the bottle survived the freezing or defrosting, I was annoyed at their constant mooching of my solvent/fuel! it was more a matter of making a very graphic point! Don't mooch AND COMPLAIN!)
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Praxichys
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[*] posted on 5-4-2017 at 08:21


Quote: Originally posted by j_sum1  

Dry ice and acetone will get you down to -78°C.
To get lower than that you need liquid nitrogen.

Time out. Solid CO2 can get no hotter than -78°C at atmospheric pressure. If you pull a vacuum on dry ice, it most certainly can get colder.

36 degrees doesn't sound like much of a stretch with a good pump. Make a slush of dry ice/ethanol, allow it to come to -78°C or so, then suck the bajeesus out of it. The ethanol will probably freeze.

Probably not practical for freezing, say, a container of ethanol though.




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XeonTheMGPony
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[*] posted on 5-4-2017 at 10:50


yes but not every one has a large vacuum chamber on hand.
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j_sum1
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[*] posted on 5-4-2017 at 15:13


Fair call, Praxichys. But I am still baffled by the wording of the OP.
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symboom
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[*] posted on 5-4-2017 at 17:10


Quote: Originally posted by j_sum1  
Fair call, Praxichys. But I am still baffled by the wording of the OP.


That is exactly what im referring to a method to drop the temperature lower Praxichys got the idea
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nezza
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[*] posted on 6-4-2017 at 02:57


Dry ice and acetone does get viscous and reaches a very low temperature. Dropping warm water into the mixture gives quite a vigorous and entertaining reaction and it can be used to flash freeze small objects.



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