Super-critical CO2 method of extraction of the natural oils
As similar to the Hexane-based solvent extraction, the CO2 –based Supercritical Fluid extraction (S.F.E.) method is another preferred method for extracting oils from the delicate flowers and plants. This method is usually deployed for extracting oils from the liquid-form matters from which the oil has to be extracted. The Hexane-based extraction, on the contrary,is deployed for extracting oils from the solid-form matrices (oil bundles).
The subject material is exposed to numerous pressurised jets of CO2 gas and thereby eliminating the lipids and other similar ingredients from the liquid hence extracted, now called as 'concretes'. These'concretes' are then mechanically washed in alcohol (Ethyl alcohol). Thereafter, the alcohol is evaporated and the left over liquid is extremely fragrant, also called as "absolute".
This extraction method comes heavy on costs as sustaining the fragrance of the 'absolutes' involves a lot of infrastructure costs.