Chemical Engineering Communications, Vol.204, No.7, 750-760, 2017
Kinetic and Mass Transfer Model for Separation of Protein Using Ceramic Monoliths as a Stationary Phase
Rigid adsorbents used as matrix skeleton have advantages over soft gel media for downstream processing of proteins. The adsorption of bovine serum albumin (BSA) has been investigated on a rigid ceramic monolith coated with cross-linked microporous agarose (D5). The physical properties of the adsorbent and the adsorption equilibria, adsorption kinetics, and mass transfer behavior have been studied for five different flow rates, with a pH value ranging from pH 4.5 to 7.0. The optimal working flow rate was 14.0cm(3)/min, and using this flow rate, increasing the pH does not generate a significant improvement in the adsorption capacity. The rates of BSA adsorption have been measured and it was possible to describe a theoretical model, in which the mass transfer involves a dispersion coefficient (k(disp)), which describes the mass transfer in the adsorbent surface, from the volume of the protein solution to the agarose surface. This parameter presents an exponential tendency by increasing the flow rate from 2.37x10(-6) to 87.40x10(-6)cm/s for n=1. Values obtained for the adsorption kinetic constant (k(ads)) followed the trend of the mass transfer parameter, increasing with the flow rate from 1.94x10(4) to 117.39x10(4)cm(2)/mols. The theoretical model predicts the protein concentration in equilibrium for successive column reuses and it can be readily used to determine the optimal reuse of column. Likewise, for a maximum flow rate of 14cm(3)/min, pressure drop was 0.04MPa, being an advantage in front of packed columns that have higher pressure drop.