7. Relevance of the model. Conclusion

Deviation from equilibrium

Solutions from a real stage are not in equilibrium. This phenomenon can be characterized by the Murphree efficiency of the stage, relative to either phase. As in the case of distillation, this efficiency can be used to determine the number of real stages using constructions similar to those of MacCabe and Thiele (see §11 of [J 1 072] ). Note that high efficiencies (of the order of 90%) can be achieved in liquid-liquid extraction.

Phase separation

In well-tuned equipment, material carryover is less than 1%. This material carryover is therefore only taken into account when very high purities are required (e.g. in the nuclear industry).