Designs of simulated moving-bed cascades for quaternary separations

IEC 100

Phillip C. Wankat and Jeung Kun Kim. School of Chemical Engineering, Purdue University, West Lafayette, IN 47907-1283
Although basic architecture is important for all simulated moving bed (SMB) systems, it is particularly important for separation of multicomponent mixtures since there are not yet standard schemes. New designs are proposed for simulated moving bed cascades separating quaternary mixtures. The local equilibrium model is used to determine the minimum desorbent-to-feed ratios D/F and productivities for 21 different SMB systems. An easy-split SMB cascade can theoretically achieve the thermodynamic minimum D/F=3.0. Based on the results, tentative selection rules for SMB systems are proposed for quaternary separations with linear isotherms. Detailed simulations agreed qualitatively with the equilibrium model predictions.