What is Short Path Distillation?
In industrial and chemical fields, people always need to extract some solvents or purify some substances. There are several ways to achieve those and short path distillation is one of them. Short path distillation is a technique that removes solvents from mixtures through evaporation. Short path distillation is mainly used for liquid-liquid separation.
The short path distillation refers to a kind of evaporation and distillation equipment. As a type of thermodynamic separation technology, the equipment can evaporate components with low boiling points by utilizing that the boiling point of each component in the mixed liquid or liquid-solid mixture is different, and then condense the material to separate the whole components. It is the combination of evaporation and condensation unit operations as well as a kind of liquid-liquid separation technology.
What is Short Path Distillation Used for?
Short-path distillation is widely used in various aspects of the national economy, especially for the separation of high boiling point and heat sensitive and easy oxide materials. The applications can be concluded as follows:
- Distillation and concentration. Short-path distillation techniques are used in natural and synthetic vitamins, wool fatty acids, lanolin, palm oil, rice bran oil, fish oil and cod liver oil, natural plant leaf root extract (such as capsanthin, lycopene, pyrethrin, The application of lecithin, b-carotene, active ingredients of traditional Chinese medicine, etc.
- Removal of solvent. With the development of new domestic and international standards and the continuous improvement of people’s living standards, the restrictions on solvent residues in chemical raw materials and their products closely related to human beings such as food, medicine, cosmetics and building materials are becoming more and more strict. Traditional distillation methods have been unable to meet the needs of the market, and this type of process often follows the extraction method as the last quality assurance system for green products.
- Decolorization and deodorization. Typical examples are: organic intermediates, lactic acid, fatty acids and derivatives thereof, APG, epoxy resins, epoxidised oils, vegetable waxes, silicone oils, brake fluids, vacuum pump oils, lubricating oils, paraffin oils, and so on.
- Preparation/production of high-boiling process materials and determination of boiling range. Short-path distillation technology can achieve distillation separation in a vacuum of 0.001 mbar and a heating time of less than 1 minute, so it is undoubtedly the preferred technology for distillation separation for those heat-sensitive high-boiling substances.
Advantages of Short Path Distillation
- The short path distillation is quite suitable for heat-sensitive compounds. The distilling temperature used for short path distillation can be much lower than the boiling point of the compound due to it is operated under negative pressure.
- The short path distillation has a quick heating process. It only requires a few seconds to complete the distillation process, while other conventional distillation apparatuses take hours to complete a distillation.
- The short path distillation can effectively reduce material waste. The liquid is only need to travel a short distance by adopting short path distillation. Hence less compound is lost during the distillation process.
- The short path distillation is much easier to use. It can achieve high distillate purity levels without large and complex apparatuses compared to conventional distillation techniques. It means that short path distillation doesn’t require large working spaces.
Short-Path Distillation VS. Simple Distillation
Distillation is widely used in the industrial field to extract or purify substances. There are several ways of distillation and the most essential one is simple distillation. Simple distillation is one single-stage distillation technique that directly condenses the boiled solvents into liquid-phase. Short-path distillation is one of the most classic simple distillation. In the short-path distillation, sample can get heated and evaporated in the specialized evaporation flask. Then gas-phase extracted solvents will be transferred along the short distance and be condensed into liquid-phase during this distance. Finally, the liquid-phase extracted solvents will go into receiving flask and be collected there. It is convenient for users to take the extracted solvents away from receiving flask. Short-path distillation is very convenient and high-efficiency for users to extract or purify substances.