Why do rotavaps suck? And what should we do?


#1

Hey,

I’ve got a couple smaller rotavaps, and I can’t help but notice they’re not very efficient for the price, nor are they very good at removing more than 80% of solvent in an oil.

I’m assuming I’m not running it wrong…but Everytime I take my oleo from the roto into the short path, I find at least 30%+ coming back in solvent. It’s annoying in quite a variety of circumstances.

Does anyone have any tips for better & convenient solvent removal? The short path seems like my best option at this point. Anyone else feel me?


#2

What kind of temps are you setting your roto water bath to?

I’ve found I need to kick it up to at least 80c to get most of the ethanol out.


#3

Ew, yeah i only fire it up to 55c usually to try and keep some turps intact.

I had thought about some kind of sloped hot plate and spray nozzle setup in a vacuum chamber


#4

If you are putting it into the short path, why would you be keeping terps? That’s just a bigger fart fraction to deal with.

Definitely give turning up the temp towards the end a whirl.


#5

#6

If your rotovap disappoints and you want to use the short path for recovery of alcohol you won’t be able to live with it . Lol. Option 1 try deeper vac and your collection vessel empty. Option 2 is decarb while in roto and that should remove everything . But then it helps when there’s a bit of alcohol left to transfer into spd or removing from roto flask In general