Evaluation of foam fractionation column scale-up for recovering bovine serum albumin

Foam fractionation is an adsorptive-bubble separation method that, according to researchers, is a feasible technique for the separation and/or concentration of proteins. The foam fractionation of bovine serum albumin (BSA) in laboratory-scale foam fractionation columns (750 and 1250 mL) and the relationship between the two laboratory-scale columns and a pilot-scale column (5000 mL) were investigated. Recovery, enrichment, and performance factor values were experimentally determined with three different column volumes with varying pore sizes, gas superficial velocities, and, in the case of the 750 mL column, foam column height. As the pore size decreased, the amount of protein recovered from the dilute protein solution increased and the enrichment decreased. As the flow rate of the gas increased, the effect of the pore size decreased. For the three column volumes, the optimal column conditions were achieved with the largest pore size (145-174 μm) and an intermediate superficial gas velocity (7 mm/s). Increasing the foam column height increased the enrichment without sacrificing the recovery of the target protein. In the case of the largest pore size, the linear relationships between the recovery and the ratio of gas volume to initial liquid volume are parallel, such that the recovery in a pilot-scale column (5000 mL) can be predicted with the recovery found with a laboratory-scale column (750 or 1250 mL).