Carbon dioxide extraction is the most common commercial method and one of the safest methods to separate CBD and other cannabinoids from hemp biomass. Carbon dioxide is a gas at room temperature. But under high pressures and fluctuating temperatures, carbon dioxide liquefies while still maintaining the fluid mobility of the gas. In this "supercritical" state, carbon dioxide acts like a solvent, flushing out the active ingredients in plants. This method is very effective because each compound can only be extracted with CO2 under certain conditions. In the supercritical state, slight changes in temperature or pressure allow fine adjustments to the extraction of CBD and other plant components. When the pressure drops, a crude, waxy, CBD-rich golden yellow substance separates from the gas and deposits in the collection container. This golden oil then undergoes a process called "overwintering", which purifies and refines the extract to improve its quality and value. Vegetable wax is not suitable for filtering out chlorophyll-free, cbd-rich oil. Supercritical carbon dioxide extraction requires expensive equipment and accurate operation. However, unlike flammable solvents such as ethanol or butane, carbon dioxide has no risk of fire or explosion.
