Principle Of Supercritical CO2 Extraction Process
By changing the temperature and pressure as well as flow rate, certain molecules will bond to CO2, allowing them to be separated from the plant.
In the supercritical state, supercritical carbon dioxide is brought into contact with the substance to be separated, so that it selectively extracts the components with different polarity sizes, boiling point heights, and molecular weight sizes in turn. Of course, the extracts obtained in each pressure range cannot be single, but the conditions can be controlled to get the best proportion of mixed components, and then the supercritical fluid is turned into ordinary gas by means of pressure reduction and temperature increase, and the extracted substances are completely or basically precipitated out, so as to achieve the purpose of separation and purification, so the supercritical fluid carbon dioxide extraction process is a combination of extraction and separation. Supercritical carbon dioxide extraction is a commonly used method to separate various components from the plant due to it producing a pure, clean, and safe product.
7 Features Of The Solubility Of Supercritical CO2 Fluids
In the supercritical state, the solubility of CO2 for different solutes varies greatly, which is closely related to the polarity, boiling point, and molecular weight of the solute, and generally has the following features:
- Lipophilic, low boiling point components can be extracted below 104KPa (about 1 atm), such as volatile oils, hydrocarbons, esters, ethers, and epoxides.
- Aroma components from natural plants and fruits, such as eucalyptus brain, muscimol, low boiling point esters from hops, etc.
- The more polar groups ( such as -OH, -COOH, etc.) of a compound, the more difficult it is to extract.
- The extraction pressure of strongly polar substances: sugar and amino acids should be above 4×104KPa.
- The larger the molecular weight of the compound, the more difficult it is to extract.
- Components with molecular weight in the range of 200-400 are easy to extract, and some low molecular weight, volatile components can even be extracted directly with CO2 liquid.
- High molecular weight substances (such as proteins, gums, waxes, etc.) are very difficult to extract with CO2.
4 Steps of Supercritical CO2 Extraction of Lycium Barbarum Seed Oil
- Dried Lycium barbarum seeds were dried or dried to get dried Lycium barbarum seeds.
- Dry Lycium barbarum seed and extractant were injected into the extractor of the supercritical fluid extraction unit 1~20 times, according to the mass volume ratio of 1 to 1~1: 20, according to the mass ratio of material to the solution, 10 times to 150min each time, and the extract was obtained.
- The extraction solution was obtained by separating the extract with the separation pressure of 0.10 ~ 1.95MPa and the separation temperature of 10~90 C by the method of reducing the temperature.
- Extraction solution is removed from the solvent, that is, the Lycium barbarum seed oil is obtained. This method not only reduces production cost, but shortens the extraction time, the amount of energy consumption, and solvent consumption in the process of reduction, and simple process, with strong operability, high extraction efficiency, environmental protection, no pollution, safety, and good repeatability and can realize continuous production of large-scale industrialization.