Is it necessary to have a bigger AND smaller rotovap?


Are there major benefits to having a smaller rotovap in addition to bigger units? I thought I read this in the EtOH Bucket-tek thread I’m loosely following but I don’t understand why it’s beneficial. Right Now I want to buy 2x 20L units, and I’m wondering if I should purchase an additional 5L or 2L rotovap if there are any significant benefits. any input would really be appreciated.



Personally i would like to have a seperate 5L for my heptane washes, and a bigger or mulriple bigger ones for my ethanol evaporation


Id get 2 20 liters, the evaporation rate on a 5 liter is much slower. 20 liters IMO are the most efficient also. Id rather have too much evaporation then not enough


I use the larger rotovap to get most of ethanol, then swap to smaller rotovap to finish it off on boiling flask so i do not have to try to move thick crude from the large flask. It is already in my final flask


If you want to purchase rotovap, chiller, spd and heating mantle, I am suppliers from china, you could dm me and tell me which equipment you want, then I could supply the quotation


I have the 5l roto, and a 2l flask and adapter. I use the 2l flask to finish and to pour easier


There would be a benefit if you needed to run smaller batches.

We have a roto designated for each solvent used to reduce cross contamination (i.e. ethanol, pentane, heptane).

Redundancy is always nice incase one needs maintenance.


Hey thanks for the input guys. Some thoughts below.

@Thetetraguy - Thanks for the notes, that sounds like a nice setup.

@Kingofthekush420 - Thanks, that’s solid info. My concern is that getting the final reduced extract out of the large 20L evap flask will be challenging, and that finishing in a smaller evap flask would maybe be advantageous for that reason and might give more fine control

@Poizzin - Thanks for the notes, makes sense. When you say boiling flask, you mean you use the smaller rotovap evap flask as same vessel you then decarb in?

@BromaW-Manager - Thank you. I’m actually already in contact with Lanphan, but I’m concerned about the equipment meeting specs/certifications to be used in my licensed lab here in Oklahoma.

@Demontrich - Thats a great idea, thanks. I’ll just have to source an adapter if I go that route.

@_TK - Can’t agree more with the statement about redundancy. I’d like the ability to run small batches, so that is also good thought. Thanks for chiming in

Thanks again for everyone’s replies!



What Poizzin was saying is there is an adapter that makes the heating bath end at a 24/40 male connection so u can connect the boiling flask that will be used for the next step onto the adapter and finish evaporating in the boiling flask and not transfer. Ive been meaning to get me one of these aswell

That would actually be a better plan is just all 20L and just a couple of those adapters


This makes a lot of sense to me as well. Having the redundancy and capacity of running all 20L setups, and just use adapters to downsize evap flask volume as needed. Thanks!



Yes indeed, doing this i don’t have transfer loss


I was just about to say get adapters as needed