- CO2 extraction is also known as Super Critical Extraction Method. Oils obtained using this method are more purer compared to steam distillation method which produces varying oil qualities dependent upon the temperature, pressure and time used for distillation. The CO2 extraction process, or supercritical extraction process, will in some cases produce a superior oil in that it has not been altered by the high heat associated with steam distillation. They are highly rejuvenating and refreshing, which makes them widely used in perfumery and medicine. Benzoin oil, Cedarwood and Coriander Oil are some variants of CO2 oils.