Using a rotary evaporator is a crucial step in many processes as it enables you to gently and efficiently remove solvents from samples. In some cases, the rate of evaporation isn’t an issue, such as when you have very little solvent to evaporate or if time simply doesn’t matter. However, in most cases, you want the process to be as fast as possible, especially if you’re running the application multiple times in succession or dealing with large volumes.
Four main ways to make your rotovap disitllation process faster:
– Increasing the evaporation flask size.
– Increasing the evaporation flask rotating speed.
– Increasing the rotary evaporator’s bath temperature.
– Increasing the vacuum level.
1.Increasing the evaporation flask size
Same as we know, the rotary evaporation flask should never be more than half full, both to prevent spillage and allow enough liquid surface area for efficient evaporation. So when we choose rotary evaporator capacity, this point must be considered.
For laboratory research, choose a small rotary evaporator is more economical and practical. But I also want to say, if you want to creat a more efficient rotovap process, bigger is generally better. As bigger flask have bigger surface, which will make more of the flask be contact with water / oil bath, makes your sample more uniform heating and faster.
In brief, larger flask will make the surface area of the sample exposed to air inside the falsk, finally makes the evaporation process more efficient.
2.Increasing the evaporation flask rotating speed
3.Increasing the rotary evaporator’s bath temperature
CBD extracts itself require lower water bath temperature to minimize thermal decomposition, so it’s important not to increase the rotary evaporator bath temperature too higher & fast.
And the evaporation temperature is also depending on the chiller you’re using, if you set too high temp.
will increase your evaporation rate to a point that the chiller can’t keep up.
So we could heating the rotary evaporator bath slowly, 30-40℃ is recommend, the condenser temperature which controlled by a low temperature circulating bath chiller, could set to -10℃ to 0℃.
4.Increasing the vacuum level
Using vacuum pump could reduced the pressure in the rotary evaporator, lower the boiling point of the solvent /
ethanol, you could finish solvent removing / ethanol recovering process at a lower temperature, protect the cbd
oil material, and could fast your evaporation rate.