Optimization of settling behavior for an efficient solvent-extraction process for bio-based components

Extraction is a downstream-process option in bio-based processes. Since the knowledge of phase-separation behavior is essential for designing efficient separation processes, this study investigates the settling and coalescence behavior of bio-based extraction systems using a standard lab-scale settling cell. The influence of different buffer media as well as of E. coli cells on coalescence was determined for the reactive extraction of hexane-1.6-diamine with isostearic acid and D2EHPA using kerosene and oleyl alcohol as diluents. As a result, an increasing pH value of the buffer significantly increases settling time. The presence of E. coli cells hinders the phase separation of the investigated systems, in particular with dispersed organic phases