Small Column Experiments for Continuous Radial Flow Chromatography

Continuous radial flow chromatography (CRFC) combines radial flow and rotating annular bed chromatography. Solution flows radially from eight fixed ports around the periphery through a rotating annular packed bed towards the axis. Loading, equilibration, elution and reequilibration solutions can be applied simultaneously at different feed ports. Protein is captured on resin in the loading zone and carried around by the annulus to the elution zone to be eluted, making the CRFC a continuous process. Small axial flow columns experiments were carried out to represent continuous BSA purification in the CRFC for a range of rotation speeds, flow rates, feed concentration, elution buffer concentration, loading sections and elution secions. Quality of the separation was measured based on productivity and height to width ratio. Best operating conditions for BSA purification in the CRFC include 720 deg/hr rotation speed, 1 mL/min flow rate, 1M elution buffer (NaCl) solution, and either 5 or 1.5 mg/mL feed solution. A wide range of loading sections and elution sections can be allocated. Combinations of these best conditions are restricted by total protein load per chromatography cycle. Mathematical models solved by finite difference method in Matlab were used to predict CRFC operation under the best conditions. Model accounts for change in solute concentration by convection, film diffusion and uptake into resin. Protein and salt parameters were adjusted to achieve best mached protein peaks. Model simulations agreed well with experimental results. Loading peak width was similar but experimental data showed broader elution peaks. Elution peak height for all simulations was greater while loading peak height were more variable than in the experiments. Peak tailing was observed in both experimental and model data