Mass transfer in aqueous two-phases system packed column

The behavior of xylanase extraction in a packed column using polyethylene glycol (PEG) 4000 and dipotassium phosphate was studied. The possibility of using the packed column in continuous operations for enzyme extraction was studied since the previous work had only addressed the semi-continuous extraction of enzyme. The influence of several kinds of packings, Raschig rings, glass spheres and polystyrene rings were studied as well the superficial velocity ratio of the salt and the PEG phases. Packed column showed a good efficiency of overall mass transfer coefficient, around three times higher than sieve plate column, for xylanase extraction. The best selectivity was obtained with the polystyrene ring where 94% of xylanase was recovery to the polymeric whereas just 3% of contaminant was recovery to this phase. The residence time distribution was adjusted by the Model of Reactors in Series. (C) 2004 Published by Elsevier B.V.