Extraction and re-extraction of phenylalanine by cationic reversed micelles in hollow fibre contactors

This work reports the extraction of phenylalanine with a reversed micellar system consisting of TOMAC/hexanol/n-heptane using hydrophobic hollow fibre modules. Extraction studies were performed under different hydrodynamic co nditions and mass transfer correlations for the shell and tube sides were d eveloped. The correlations were determined using a one-step calculation met hod and the results obtained are in agreement with the literature for the r ange of Reynolds numbers studied. Based on the obtained correlations and on the resistance in series model, a transport model was developed in which the phenylalanine concentration in the feed phase can be predicted during the experimental run. For the extrac tion process the model developed describes satisfactorily the evolution of phenylalanine concentration with time under different hydrodynamic conditio ns. The re-extraction process was found to be kinetically controlled due to the higher dynamic stability of reversed micelles when contacting a stripp ing phase with high ionic strength. The experimental results obtained were described using a kinetic model developed. Simultaneous extraction/stripping of phenylalanine was also accomplished us ing two hollow fibre modules in series, using different volume phase ratios . The mass transfer process was modelled and compared with the experimental results. (C) 1999 Elsevier Science B.V. All rights reserved.