Description
Carbon dioxide supercritical extraction is one application of the supercritical fluid extraction (SFE) process. SFE is a separation technology that uses supercritical fluid solvent for extraction. Carbon dioxide is the most commonly used supercritical fluid, with other choices including ethanol. Compared with traditional soxhlet extraction, SFE uses supercritical fluid to provide a broad range of useful properties. It eliminates the use of organic solvents, which reduces the problems of their storage, disposal, and environmental concerns.
In the extraction process, diffusion coefficients of lipids and waxes in supercritical fluids are much higher than in liquids, therefore extraction can occur more quickly. In addition, no surface tension is present in supercritical fluids, and viscosities are much lower than in liquids, which help the supercritical fluids be able to penetrate into small pores that are inaccessible to liquid.