New developments in simulated moving bed chromatography

In the last decade the concept of simulated moving bed (SMB) chromatography has been successfully applied in several fields, e.g. for the separation of enantiomers and the purification of pharmaceutical proteins. Often the separations were realized with the classical implementation of the process using four distinct zones and constant operating conditions (e.g. switching times, liquid phase velocities and solvent strengths). In order to further increase the potential of SMB chromatography, several increasingly sophisticated modes of operation have been developed based on applying gradients and on dynamically varying certain parameters during the separation. Examples include new process variants VariCol [1], PowerFeed [2] and ModiCon [3]. Another alternative capable to enhance the process performance is based on the introduction of an enrichment step between zones I and II [4,5]. Besides treating binary mixtures, research increasingly focuses on continuous processes capable of performing multicomponent separations. To achieve separation of a ternary mixture different approaches have been suggested using increased numbers of zones (ranging from 5-Zone open loop up to 14-Zone closed loop setups[6]). Recently was discussed a 8-Zone closed loop separation unit utilizing an external enrichment step [7] was discussed. In the presentation, we will finally also discuss the potential of different new strategies based on partial product collection and feed-back of fractions which do not fulfill required specifications. References: [1] M. Bailly, P. Adam, O. Ludemann-Hombourger, R.M. Nicoud, WO 2000025885 (2005) [2] Z. Zhang, M. Mazzotti, M. Morbidelli, Journal of Chromatography A 1006 (2003) 87. [3] H. Schramm, A. Kienle, M. Kaspereit, A. Seidel-Morgenstern, WO 2004014511 (2004) [4] M. Bailly, R.M. Nicoud, P. Adam, O. Ludemann-Hombourger, US 2006124549 (2006) [5] G. Paredes, H.K. Rhee, M. Mazzotti, Industrial & Engineering Chemistry Research 45 (2006) 6289. [6] P.C. Wankat, Ind. Eng. Chem. Res. 40 (2001) 6185. [7] L.C. Keßler, A. Seidel-Morgenstern, Journal of Chromatography A 1126 (2006) 323