2. Extraction and fractionation

2.1 General architecture of extraction/fractionation processes

The originality of supercritical fluids lies in the fact that it is easy to implement a continuous variation of their solvent power, which makes it possible to carry out very complex fractionation operations: for example, the variation of the solubility of products in the supercritical solvent can be used as a function of temperature at constant pressure within the contactor, and as a function of pressure at constant temperature during decompression.

• When a liquid mixture containing two closely related molecules (or families of molecules) needs to be fractionated, a high-performance contactor is used, featuring a multi-stage counter-current contact. Selectivity of the separation...