What Is Molecularly Distilled?

What Distillation Means

• All forms of distillation separate mixtures of different substances from one another, leading to purified samples of the substances that were previously mixed together. Distilled water, for example, has been purified of dissolved minerals using a simple form of distillation. The vapor consists of the substances with the lowest boiling points, whereas those with the highest boiling points --- such as minerals --- remain in the original sample. The vapor, now free of minerals, can then be condensed in another chamber and used for projects requiring distilled water.

Molecular Distillation

• Molecular distillation involves placing the liquid in need of purification into a vacuum distillation device, which usually consists of at least two chambers connected via a variety of tubes. Rather than boiling the liquid, a vacuum connected to the device reduces the pressure to a level below the sample's vapor pressure, which causes the sample liquid to evaporate into a gas and move through the device. A cooled chamber called a cryotrap condenses the substance in need of purification, and water is trapped in a condensing column along with other dissolved substances not removed in the cryotrap.

Why It's Done

• Molecular distillation is usually the distillation method of choice for purification of substances that have a very high boiling point or mixtures that cannot be boiled for other reasons. For example, some compounds decompose when heated. A substance that falls apart when heated would thus be be destroyed before it ever reached its boiling temperature. Molecular distillation is, therefore, often the distillation method of choice for oils.

Uses of Molecular Distillation

• Environmental cleaning often makes use of molecular distillation, and the procedure is also commonly used in the processing of crude oil. If you are a user of nutritional supplements, you may also notice that some fish oil brands market molecular distillation as a supposed benefit, with the claim being that molecular distillation is the most effective method of removing heavy metal contaminants from the product, although the flip side is that the procedure also removes some of the beneficial vitamins from the fish oil.