Difference between simple and short-path distillation
Rotary evaporator and short path distillation are both used to concentrate or extract substances from mixtures. They are very similar but still have some differences between them. Next, let’s go through the differences between rotary evaporator and short path distillation:
1. Different working principles. Rotary evaporator keeps rotating the evaporation flask by electric, in order to enlarge the evaporation area to accelerate the evaporating speed. Short path distillation decreases the pressure within the distillation equipment, in order to decrease substances’ boiling points. Compared with under normal pressure, many substances’ boiling points could decrease 80C-100C under pressure 1.3-2.0KPa.
2. Different applications. Rotary evaporator is mainly used to continuously distill volatile solvent under reduced pressure in chemical, industrial, biology medicine and so on. Short path distillation is mainly used for the separation and extraction of high boiling point substances and the compounds which have been thermally decomposed, oxidized or polymerized without reaching the boiling point at atmospheric distillation.
3. Different parts. Rotary evaporator consists of rotor, evaporation flask, heating mantle, condensing tubes and so on. Short path distillation equipment consists of evaporation flask, vacuum pump, protection and pressure-measuring part. The glassware in the whole equipment must be made of thick glass. Otherwise, the short path distillation equipment could explode because of the uneven force on the glassware.
Short path distillation applications
Short path distillation is widely used in many fields, for example, petrochemical industry, pharmacy industry, oil production industry, food-processing industry and other fields. Therefore, there are so many applications of short path distillation, and they are as follows:
1. In petrochemical industry, the applications are waste oil regeneration, oil deweighting, ammonia, amine, quinoline derivatives, epoxy resin, resinous acid, isocyanate, isobutyl ketone, peroxide, liquid crystal, polyethylene glycol, silicone oil, softener and so on. Among these applications, waste oil regeneration is very environment-protecting and energy-saving, because regenerating waste oil products more oil that people can use, which means people can make full use of waste oil.
2. In pharmacy industry, the applications are amino acid ester, polymer intermediate products, vitamin E, vitamin life and so on. Among these applications, vitamin E is widely used in skin care field and is very popular nowadays.
3. In oil production industry, the applications are diglycerides, dimer fatty acids, fatty acids, fatty acid derivatives, polyglycerides, acids, wool ester alcohol and so on.
In food-processing industry, the applications are monoglyceride, lauric acid, propylene glycol, l-lactic acid, cod liver oil, rice bran oil, wheat germ oil, cinnamon oil, rose oil and so on. Among these applications, rose oil is used in skin care field a lot. Cinnamon oil is used in skin care and health care a lot, especially dispelling wind and dampness, warming and strengthening spleen and stomach.