Rotary Evaporator Use

The rotary evaporator was first invented by an American biochemist, Lyman C. Craig, in 1950. Since its invention, the rotary evaporator machine has developed significantly, and it is used for several applications in today’s world. In this article, we shall be going through rotary evaporator use in several applications.

What Is A Rotary Evaporator?

rotary evaporator use
RE-501 Rotary Evaporator

A rotary evaporator is a device that aids in removing solvents from samples through evaporation; the device is often used in chemical laboratories. The primary purpose of distillation is separating a particular mixture into components that are based on their respective volatilities via evaporation and condensation. A rotary evaporator is highly essential in pharmaceutical industries, chemical use as well as educational use.

Usually, a rotary evaporator involves reducing the solvent’s volume by distributing it into a thin film within the vessel’s interior at high temperatures as well as reduced pressure. This process enables you to get rid of excess solvent rapidly from less volatile samples.

There are four major components in most rotary evaporators. These components include; rotor condenser, rotor, solvent trap, and a heat bath. Furthermore, a vacuum pump or aspirator will have to be attached along with a bump trap as well as a round bottom flask with samples that needed to be concentrated.

>> Rotary Evaporator Parts and Their Functions

When a liquid is put in the round bottom flask, the rotary evaporator will spin and heat the flask as it reduces the pressure by creating a vacuum. The liquid will start to evaporate at a very low temperature due to the vacuum formed.

As the liquid changes state into gas, it will be collected in a different flask as it cools back into a liquid state. Once this is done, any substance that was present in the liquid will be left-back. For instance, the salt will be left back when water mixed with salt evaporates.

A rotary evaporator is an essential device, and it is often used by scientists to separate solvents from a liquid. The best part is that using a rotary evaporator is much faster when compared to an evaporating basin. Furthermore, they are ideal when it comes to distillation.

The Uses of Rotary Evaporators (What Is the Purpose of Rotary Evaporation?)

As previously mentioned, rotary evaporators are used by scientists in separating solvents from liquids. Here are three main uses of rotary evaporators among others;

1. Pharmacy industry

pharmaceutical rotary evaporator

In the pharmaceutical industry, the rotary evaporator is used in separating chemical solvents.

Furthermore, it is used in creating several high-quality pharmaceutical products. Rotary evaporators are essential in the pharmacy industry due to their low boiling point effect on solvents. This makes it easy to work with various chemicals and chemical solvents in creating valuable pharmaceutical products at an affordable cost.

Industrial rotary evaporators are as well used in separating solvents in various polymeric, organic, and inorganic materials. This makes it for scientists to design pharmaceutical drugs. Since the device separates solvents from liquids without forming azeotrope, it has become more desirable for pharmaceutical use.

2. Educational use

educational rotary evaporator use

With a rotary evaporator, students can learn more about the techniques of evaporation and condensation. Educational rotary evaporator features several applications that are useful and can be put into practice by students; this makes it a relevant device in an educational system.

In addition to separating the solvent from liquids, students will as well learn how to extract volatile aroma and flavor molecules from different mixture incredibly low temperatures. For instance, they will be able to obtain the desired flavor from alcoholic drinks, fruits, and herbs without having to heat the mixture.

Moreover, they will learn how they can concentrate on non-volatile components in a mix. For instance, they will be able to concentrate fresh and pure flavors from blood orange by getting rid of water.

Since educational rotary evaporates features various application, it becomes essential for students to learn more about it and ways in which they can operate. Through that, they will learn that the rotary evaporator is not only ideal for pharmaceutical uses but also a kitchen, chemical engineering, and industries, among others. This will aid them in shaping their skills even better.

3. Chemical use

chemical rotary evaporator use

Laboratory rotary evaporator plays a significant role when it comes to chemical engineering. Crystallization, evaporation, separation, drying, and solvent recovery process is vital when it comes to chemical engineering, and to achieve that, you will require a rotary evaporator. As previously mentioned, rotary evaporation applications spread to the cooking industry, which referred to as molecular cooking.

Molecular cooking, also known as molecular gastronomy, is a scientific chemical principle that applies in the cooking industry. To separate two chemical compounds in liquids and achieve aromatic fragrance, you will require a rotary evaporator.

How to Set Up A Rotary Evaporator

Setting up a rotary evaporator is relatively easy; here are the key steps to follow;

  • Ensure that your round bottom flask is double the volume of your sample.
  • Elevate your vacuum pump. Ensure that it is above the traps; this will aid in keeping your solvent out of your pump.
  • Hook up your tube and label it in and out on your dry ice trap.
  • Add a closing and opening valve in between the vacuum pump and the last trap. This will aid in removing solvent from your trap.
  • For the vacuum to be strong, ensure the inside of your tubing is large enough. Usually, the recommended tubing size is 3/16 inch wall thickness by 5/16 inch interior diameter.
  • Dry ice is essential for maintaining a cold atmosphere and condensing the solvent. You might as well consider using rock salt, ice as well as water slurry; however, it will best for you to test how the system operates.
  • You should use glycerin in wetting your glass when using glass as a part of your connection in the side-arm flask. Moreover, put on gloves to protect your hand and hold your glass next to the pressure point as you put the vacuum tube on.
  • Ensure that your dry ice’s temperature is -78.5 degrees Celsius.


By now, you have understood the function of a rotary evaporator and how essential it is in our daily life. The primary purpose of a rotary evaporator is to separate solvents from liquids. The best part is that it can be used in several useful applications, which make the rotary evaporator one of the most useful machines in today’s world.