Concepts of phase separation in supercritical processing

Processes using supercritical fluids and especially supercritical fluid extraction (SFE) have been thoroughly investigated as a method to obtain high valuable products for more than 20 years. A lot of scientific effort has been dedicated specially in demonstrating the advantages of SFE with respect to the enhanced nutritional value of the natural extracts obtained. Although thermodynamically consistent, up-scaling of such concepts often fails due to a lack of technically and economically feasible solutions. This work focusses on technical aspects of phase separation and product recovery as a decisive process step in laboratory, pilot and industrial scale extraction of solids and liquids. Different methods of liquid level detection are presented as a way of controlling extract separation automatically. The results are discussed in view of guidelines for finding appropriate solutions to the specific separation problem.