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

Abstract 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 conditions and mass transfer correlations for the shell and tube sides were developed. The correlations were determined using a one-step calculation method and the results obtained are in agreement with the literature for the range 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 extraction process the model developed describes satisfactorily the evolution of phenylalanine concentration with time under different hydrodynamic conditions. The re-extraction process was found to be kinetically controlled due to the higher dynamic stability of reversed micelles when contacting a stripping phase with high ionic strength. The experimental results obtained were described using a kinetic model developed. Simultaneous extraction/stripping of phenylalanine was also accomplished using two hollow fibre modules in series, using different volume phase ratios. The mass transfer process was modelled and compared with the experimental results.