Nicole Kopriwa

A Critical Review of the Application of Drop-Population Balances for the Design of Solvent Extraction Columns: I. Concept of Solving Drop-Population Balances and Modelling Breakage and Coalescence

Population-balances are a powerful method to predict the population behavior of drops in chemical-engineering equipment such as solvent extraction columns. In such columns a complex interaction of different phenomena, namely drop sedimentation, mass transfer, drop breakage and coalescence as well as axial dispersion occurs. In this article the concept of drop-population balances is discussed in detail as well as possible solution methods. Also, a critical review of existing models accounting for breakage and coalescence taking place in extraction columns is presented. Future parts of this series will be devoted to modelling mass-transfer and sedimentation as well as on application of single-drop based modelling.

Characterization of Coalescence in Extraction Equipment Based on Lab-Scale Experiments

ABSTRACT Design of an extraction apparatus is significantly influenced by the coalescence behavior of a given material system. At the same time, quantifying coalescence of a system in an extraction column is tedious, as pilot-plant experiments have to be performed. These tests have to be carried out for each system individually, as coalescence is strongly influenced by traces of impurities. On the other hand, coalescence behavior for designing mixer–settler processes can be quantified in simple discontinuous lab-scale settling tests.