Maximizing sorbent life: comparison of columns in parallel, lead-lag series, and with bypass blending.

Various adsorption column configurations can be used to increase fractional utilization and decrease adsorbent usage rate. This study compared the adsorbent usage rate of different column configurations. Mathematical models simulated chromatographic breakthrough front shapes and determined adsorbent usage rates. A configuration selection diagram based on percent mass-transfer zone (MTZ) and target C/Co (effluent concentration/influent concentration) was created to compare the adsorbent usage rate of configurations for single component systems. The target C/Co determined the column configuration with the lowest adsorbent usage rate when the MTZ was a large percentage of the column (> 60%), while all column configurations generally performed similarly at short percent MTZs (< 30%). Bypass blending was found to be most effective with a lead-lag configuration and the maximum amount of bypass. A sensitivity analysis determined that competitive adsorption can significantly change the configuration selection diagram and generally makes lead-lag more competitive compared with parallel column configurations.