Molecular distillation is a special liquid separation technology. It is different from the traditional distillation based on the principle of boiling point difference separation. Instead, it achieves separation based on the differences in the average free paths of molecular motion of different substances. Molecular distillation is a distillation method operated under high vacuum. The average free path of vapor molecules is greater than the distance between the evaporation surface and the condensation surface. Therefore, the differences in evaporation rates of each component in the feed liquid can be utilized to separate the mixed liquid.

Traditional distillation relies on the differences in boiling points among various substances for separation, making it difficult to extract certain substances that are prone to oxidation, decomposition or polymerization at their boiling temperatures.

The separation function of molecular distillation is to separate substances by taking advantage of the fact that liquid molecules escape from the liquid surface when heated. Different types of molecules have different average free paths of motion after escape. The mixed liquid flows down the heating plate. After heating, both light molecules and heavy molecules escape into the gas phase. Due to the different free paths of light molecules and heavy molecules, light molecules have a larger free path and can reach the plate condenser. After condensation, they can move down along the plates of the condenser. When flowing, the free path of heavy molecules is small, and they cannot reach the condensation surface, thus becoming saturated in the gas phase and returning to the liquid phase, flowing downward along the heating plate, thereby forming the splitting and separation of light and heavy molecules.

Molecular distillation features high operating vacuum, low heating temperature, short heating time and high separation efficiency. It is particularly suitable for the separation of high-boiling-point, heat-sensitive and easily oxidized substances.

Compared with traditional distillation, molecular distillation has obvious technical and economic advantages:

1. High product quality. Due to the low operating temperature and short heating time of molecular distillation, products with high purity and good original quality can be obtained, which is particularly important for natural substances.

2. Low product cost. Due to the high separation efficiency and high product yield of molecular distillation, it can significantly reduce production costs.