PERFUSION CHROMATOGRAPHY - THE EFFECTS OF INTRAPARTICLE CONVECTIVE VELOCITY AND MICROSPHERE SIZE ON COLUMN PERFORMANCE

A mathematical model describing the dynamic adsorption in columns with spherical bidisperse perfusive or spherical bidisperse purely diffusi ve adsorbent particles is presented and its solution is obtained numer ically. The adsorption of bovine serum albumin on spherical anion-exch ange porous particles was studied for different values of the intrapar ticle Peclet number, Pe(intra) and of the microsphere diameter, d(m). The results show a departure from spherical symmetry of the isoconcent ration profiles of the adsorbate in the porous adsorbent particle as P e(intra) increases. This spherical asymmetry increases the adsorbate a vailability in the pore fluid of the macroporous region and also incre ases the concentration of the adsorbate in the adsorbed phase in the u pstream half of the spherical adsorbent particle. If, for example, the concentration profiles of the adsorbate in the adsorbed phase of the porous adsorbent particles could be determined experimentally and if t hese profiles show a departure from spherical symmetry, then this resu lt could suggest that the porous adsorbent particles may have exhibite d perfusion behavior under the conditions of operation of the column. The dynamic percentage utilization of the adsorptive capacity of the c olumn increases as Pe(intra) increases and d(m) decreases. The percent age breakthrough to be selected for column switching is influenced by the magnitude of Pe(intra) because of its effect on the dynamic percen tage utilization of the adsorptive capacity of the column.