Rotary evaporators are standard laboratory equipment found in nearly all laboratories. Chemical, pharmaceutical, food, and environmental industries are the most common users, but rotary evaporators, or “rotovaps,” may be found wherever processes require sample concentration or solvent distillation.

Rotary evaporator is better to use when you want to get rid from the solvent. Let’s say you have a solution of some chemical in some solvent. If you want to obtain a crystal form of the chemical, you may put solution to rotary evaporator and evaporate the solvent.

If you want to purify a solvent or other chemical which is liquid at normal conditions, you use distillation.

The difference is that with rotary evaporation you don’t really care what happens with vapors of the solvent, but distillation setup is specifically built for collecting vapors, and even separating vapors of different compounds.

The rotovap can be used for two purposes:

1) concentrate non-volatile components in a mixture (e.g, concentrating flavors from a blood orange by removing the water)

2) to extract the volatile aroma and flavor molecules from mixtures gently (e.g., extracting the desired flavors from a blend of alcohol, herbs, and fruit without heating the mixture up). The key to understanding any distillation is to remember that it is a separation. Sugars, acids, colors, and most bitter compounds are separated from aromas, alcohols, water, and small flavor molecules, etc.

Advantages of therotary evaporator

With a vacuum rotary evaporator you can carry out single-stage distilla-tion runs quickly and gently.The evaporation capacity of a rotary evaporator is about 4 timesgreater than that of a conventional, static distillation apparatus. Heattransmission in the heating bath as well as inside the flask is greatlyimproved by rotation of the evaporating flask. Rotation greatly enlargesthe active surface inside the flask, hastening the evaporation. With theliquid remaining at any one point of the flask wall for a short time only, itis subject to minimum stress during the distillation (no overheating, noincrustation). Bumping and foaming are greatly reduced by the rotation.

Why Vacuum control is necessary for Distillation or Evaporation in Rotary Evaporator