Supercritical fluid extraction is a process that separates one component from another using supercritical fluids. A supercritical fluid is a substance that is at a pressure and temperature above its critical state.
A supercritical fluid has properties associated with both gases and liquids. It can effuse through solids and dissolve materials. Carbon dioxide in its supercritical fluid stage is commonly used for extraction in the food, pharmaceutical and chemical industries. In this process, samples of the components to be extracted are placed in a chamber along with carbon dioxide. The chamber is pressurized until the carbon dioxide becomes a supercrtical fluid. The substance extracted is solubilized by the supercritical carbon dioxide. The contents are then depressurized, causing the carbon dioxide to lose its supercritical fluid properties and create the desired components.