supercritical-fluid extraction

Supercritical-fluid extraction (SFE) is a chemistry technique used for large-scale purification of complex liquid or solid materials. It utilizes a substance in a supercritical state, which exists at temperatures and pressures above its critical point. In this state, the substance is denser than a gas but less dense than a liquid, allowing it to dissolve substances effectively while maintaining low viscosity.1

A key advantage of SFE is the ease of removing the supercritical fluid after extraction. By reducing the temperature or pressure, the fluid returns to a gaseous state, leaving the extracted substances behind as a liquid or solid. This eliminates the problem of residual extracting liquid, as seen in the common example of removing caffeine from coffee.1