Short path distillation can be used to
Short path distillation can be used to industries such as food, medicine, fine chemicals and cosmetics. It is especially suitable for the concentration, purification or separation of high molecular weight, high boiling point, high viscosity substances and organic mixtures with extremely poor thermal stability.
Short path distillation is a continuous distillation process in which separation operations are performed under high vacuum. Under high vacuum conditions, since the distance between the heating surface and the condensation surface of the short-path distiller is less than or equal to the mean free path of the separated material molecules, when the molecules evaporate on the surface of the liquid film formed on the heating surface of the short-path distiller, the intermolecular They do not collide with each other, move to the condensation surface without hindrance and are condensed on the condensation surface, so short-path distillation is also called molecular distillation. Since short-path distillation is performed under high vacuum at a temperature far below the boiling point, and the distillation time is very short, this process has become the mildest distillation method for separating the target product.
Application areas of short-path distillation
After more than 60 years of processing and exploration of thousands of substances, short-path stills have been widely used. Its industrial applications include food, cosmetics, pharmaceuticals, aerospace, plastics, petrochemicals, wax, paper, and chemical industries.
1. Food processing industry: refining edible oil, separating fatty acids and antioxidants and other high-value products.
2. Cosmetics industry: extract lanolin, spices and other products.
3. Pharmaceutical industry; natural vitamin A and vitamin E, and natural medicines including tranquilizers, etc.
4. Coatings and paint industry: improve the drying performance and hardness of polymer oils such as sesame oil and linseed oil.
5. Epoxy resin production: make the color of epoxy resin lighter, reduce viscosity, and extend storage life.
6. Silicon production: easy to remove low molecular weight or high molecular weight polymers from polymer mixtures.
7. Wax production industry: purification of natural paraffin wax, beeswax, palm wax and some microcrystalline waxes and high melting point waxes.
8. Surfactant production industry: the extraction of glycolipids, polyoxyalkylene glycols, natural fatty acids and fatty acid wax products.
9. Mineral oil production: used for high-temperature lubricating oil and grease, generally extracted from petroleum residues.
The process of short-path distillation
1. The liquid film formation of the material on the heating surface: a fast-moving film with uniform thickness is produced on the heating surface of the distiller by mechanical means.
2. Free evaporation of molecules on the surface of the liquid film: The molecules evaporate in a high vacuum at a temperature far below the boiling point.
3. The movement of molecules from the heating surface to the condensing surface: As long as the short-path distiller guarantees a sufficiently high vacuum so that the mean free path of the evaporated molecules is greater than or equal to the distance between the heating surface and the condensing surface, the movement of the molecules to the condensing surface and The evaporation process can proceed quickly.
4. The capture of molecules on the condensation surface: As long as there is a sufficient temperature difference between the heating surface and the condensation surface, and the shape of the condensation surface is reasonable and smooth, the light components will condense on the condensation surface. This process can be instantaneous carry out.
5. Collection of distillate and residue: Due to gravity, the distillate is collected at the bottom of the condenser. The heavy components that did not evaporate and the very few residues of light components returning to the heating surface slide down to the bottom of the heater or the outer edge of the turntable due to gravity or centrifugal force.
