Separating pure extract component(s) from mixture by liquid-liquid or gas-liquid extraction, involves successive stages using extractants with decreasing capacity but increasing selectivity

摘要

Separation of at least one extract component (I) from a mixture by liquid-liquid or gas-liquid extraction is carried out in at least two successive extraction stages, in which the capacity of the extractant (II) for (I) decreases from one stage to the next but the selectivity of (II) for (I) increases from one stage to the next. An independent claim is included for the corresponding extractant (II), with capacity and selectivity for (I) varying as above.