Carbon Dioxide (CO2) is a non-toxic, naturally occurring colourless and odourless gas at normal atmospheric temperatures and pressures. At elevated temperatures and pressures, CO2 reaches a “supercritical” state that causes it to behave like both a gas and a liquid. In a supercritical state, CO2 exhibits high diffusivity and is able to permeate plant material very effectively. Once in contact with the plant material, supercritical CO2 acts as a powerful solvent that is extremely effective at dissolving essential oils.
The supercritical CO2, acting like a liquid, is then able to hold the extracts in solution until the mixture undergoes a controlled phase change back to its gaseous state. Since the CO2 gas is no longer able to hold on to the extracted material it can then be collected as it drops out. CO2 is the perfect solvent and is unique because its power can be easily modified by adjusting temperature and pressure settings at key points during the extraction process.