I’ve been reading a lot and I want to get other opinions on this but which solvent is best for rotovap? A lot of people talk about 200 proof myself I usually use 190 proof but now there are 200 proof mixed with heptane. Just curious
Ummm i think u need to keep reading…
Rotovapes are compatible with most solvents.
3 Likes
I like pentane in my rotovap it’s like driving Nascar or something haha.
Heptane denatured alcohol is pretty annoying to even think about
4 Likes
Why is heptane/ethanol pretty annoying? wondering because i just bought 55gallons of it…I havent started extracting with it yet but wanted to try it to get around the excise tax… Hope i didnt make a costly mistake.
Takes longer to purge
4 Likes
Thanks for the response. do you have any idea how much longer?
Depends on too many variables. Longer, though I know the ternary azeotrope of heptane/ethanol/water should come off first so a small addition of water to your mix as it hits the roto should help ensure of total purge of the heptane followed by ethanol
3 Likes
Because you should’ve just bought methanol if you’re trying to save costs.
Methanol is better than ethanol…
1 Like
put butane in if your condenser is cold enough.
1 Like
You could just off gas the top of the condenser into a bucket of dry ice. Sounds fun lol
1 Like
Methanol takes soooo much longer to evap for some reason
1 Like
Methanol’s latent heat of evaporation is about 20% greater than ethanol’s
So is it harder to evap or condense? I would think methanol would evap faster and be more difficult to condense. It does go slower than ethanol. That was nyborgs excuse for his ffe lol
Evaporation and condensation require the same energy. So more energy input for both. Just at lower temperatures…
2 Likes
Op, you’re getting these responses because your question is vague… What do you want to achieve with your process and what it your process… Assuming your extracting something and not crystallizing CBD, are you trying to pick a solvent to extract with? Lots of things to consider beyond rotovap compatibility
This is why I love the forum even if I can’t remember why something is the way it is someone is going to
I would love it if a Chem E would drop in and give a more in-depth explanation of why methanol boiling point being lower requires more energy to phase change than ethanol
1 Like
Same!
Huh, I just checked the Wikipedia data pages for etOH and meOH and methanol is lower heat capacity and lower heat of vaporization so that means it’s supposed to take less energy to heat and to boil methanol…
1 Like
Also means it takes less energy (to run a chiller) to condense
2 Likes