An optimal three fractions yielding simulated moving bed chromatographic separation: Triple switch SMBC

摘要

Among the various degrees of freedom Simulated moving bed chromatography possesses, the current work deals with manipulation of operating conditions comprising internal flow rates and switching period. The conventional mode of operation yields a single fraction of the extract and raffinate with a single set of operating conditions whereas the current work proposes a novel triple switch mode of operation which is characterised by three sets of internal flow rates and switching period and yields three fractions. Under optimal conditions, the higher degrees of freedom have the potential of yielding higher extract purities than conventional as well as dual switch modes of operation with two sets of operating conditions. A multi-objective optimisation problem has been solved which maximizes the purity of one of the three extract fractions, for a certain minimum extract recovery and minimum feed flow rate. It is through a lower purity in two of the three fractions that a superior extract purity is achieved. This finding has been corroborated by a modeling based study on the linear adsorption isotherm based separation of fructose-glucose in deionised water on a cation exchange resin.