[slekce]

Hey, I've got a vacuum pump hooked up to a condenser that's running pretty much 24/7. Up until now, I've been putting pure dry ice in it to keep it cool, but the bills are starting to rack up... I'm wondering what you guys think of putting some kind of solution or slurry in it? Maybe an aqueous solution with a depressed freezing point, or some combination of acetone and dry ice? Any and all advice is appreciated!

[Archer]

This is highly dependent on the vacuum, what the cold trap is collecting and how much material it is collecting a day.

Could you elaborate a little?

I used to use liquid N₂ for an industrial short path distillation but this was 10^-3 mbar and had to stop 5-20% heptane and low mw terpenes from the feed material entering the pump.

[curiouscat]

Hey, I've got a vacuum pump hooked up to a condenser that's running pretty much 24/7. Up until now, I've been putting pure dry ice in it to keep it cool, but the bills are starting to rack up... I'm wondering what you guys think of putting some kind of solution or slurry in it? Maybe an aqueous solution with a depressed freezing point, or some combination of acetone and dry ice? Any and all advice is appreciated!

On scale often sequential units help: Cool down to say 15 C using tap cold water, then down to 0 C with iced chilled water or brine and let dry ice etc. do only the heaviest lifting.

You'll save a lot by using multiple staged fluids.