What is the Difference Between Molecular Distillation and Short Path Distillation?

Molecular distillation and short path distillation are both analytical techniques used to separate and purify materials, particularly for compounds that are not stable at high temperatures or those that require minimal thermal stress. The main differences between these two techniques are:

Pressure: Molecular distillation typically operates at an even lower pressure than short path distillation, usually less than 1x10^-2 mbar. This reduces the mean free path of any molecule leaving the evaporator, ensuring that the molecule's trajectory is longer than the distance between the evaporator and condenser.
Efficiency: Short path distillation is generally faster and more efficient than molecular distillation, and is especially useful for compounds that are not stable at high temperatures. It can complete a separation in a matter of seconds due to the vacuum pressure it implements, which helps speed up the process.
Application: Short path distillation is often used to separate materials such as fragrances, fatty acids, fuels, polyurethane, and oils like CBD oil. Molecular distillation, also known as high vacuum wiped film, thin film, or short path distillation, is a well-known process to separate thermally sensitive materials.

In summary, molecular distillation is a special form of short path distillation that operates at even lower pressures, ensuring minimal thermal stress for the product. Both techniques are used to separate and purify materials, but short path distillation is generally faster and more efficient.

On this page

What is the Difference Between Molecular Distillation and Short Path Distillation?

Comparative Table: Molecular Distillation vs Short Path Distillation

Here is a table comparing the differences between Molecular Distillation and Short Path Distillation:

Feature	Molecular Distillation	Short Path Distillation
Description	A type of short path vacuum distillation that uses an extremely low vacuum pressure.	A method of separating compounds based on their unique boiling points, used to purify and isolate heat-sensitive compounds.
Distance	Short-term exposure of the distillate liquids to high temperatures, with a short distance (about 2 cm) between the evaporator and the condenser.	The distillate travels a short distance (as short as 2 cm) between the evaporator and the condenser.
Pressure	Extremely low vacuum pressure.	Reduced pressure, but not as low as molecular distillation.
Temperature	Heating temperature can be accurately controlled to avoid damage to thermally sensitive molecules.	Heating crude oil in a boiling flask and agitating it with a magnetic stirrer.
Uses	Suitable for natural products, complex compounds, and thermally sensitive molecules such as vitamins and polyunsaturated fatty acids.	Used to separate compounds with unique boiling points, such as THC and CBD.
Setup	Can be more complex and challenging to set up due to the need for a strong vacuum.	Can be simpler and more straightforward to set up compared to molecular distillation.
Scalability	Limited scalability and production capacity.	Can be more easily scaled up for larger production volumes.

In summary, molecular distillation is a specific type of short path distillation that operates at extremely low vacuum pressures, making it suitable for heat-sensitive compounds. Short path distillation, on the other hand, is a more general method that separates compounds based on their unique boiling points and can be scaled up more easily for larger production volumes.

Guilherme Mazui

Guilherme Mazui is graduated in journalism from the Federal University of Minas Gerais (UFMG) and a master's degree in Communication from the University of São Paulo (USP). In addition, he has experience in advertising writing and has worked as a content editor in several companies.