What is supercritical carbon dioxide extraction?
One of the newer extraction methods is supercritical carbon dioxide – also used to make decaffeinated coffee. It has the advantage of not leaving petrochemical residues in the product and preserving the very fine top notes which steam distillation usually destroys. While supercritical carbon dioxide does not directly yield an absolute, it will extract both the waxes and the essential oils which make up a concrete. Then this result undergoes further processing with liquid carbon dioxide, to separate the waxes from the essential oils without decomposing (or denaturing) the compounds. When this is done, the pressure is reduced, reverting the carbon dioxide back to a gas. No residue from the process is left in the resulting waxes and essential oils.
