Enzyme mass transfer coefficient in aqueous two‐phase systems: Modified spray extraction columns

Abstract

AbstractThe fractional dispersed phase hold‐up and mass transfer coefficients were measured in modified spray columns of 50 mm i.d. using an aqueous two phase system of polyethylene glycol (PEG 4000)‐sodium sulphate‐buffer. The mass transfer coefficients were measured for amyloglucosidase and β‐galactosidase. Both co‐current and countercurrent modes of operation were investigated.The dispersed phase hold‐up (ϵD) and the dispersed phase and the continuous phase mass transfer coefficients (kDa, kCa) increased with increasing dispersed phase velocity. An increase in the phase concentration of sodium sulphate and PEG was found to reduce ϵD, kDa, and kCa. The performance of the modified spray column is compared with the conventional spray column. The modifications resulted into about a ten‐fold enhancement in the throughput and about a five‐fold reduction in the value of the height of a transfer unit (HTU ). It has been shown that the value of HTU of the order of 1 m can be obtained. Empirical correlations for ϵD and kDa, kCa have been proposed.