Chiral separation by SMB chromatography

The paper deals with chiral separation by simulated moving bed (SMB) chroma tography. A model for the prediction of the cyclic steady-state performance of the SMB, based on the analogy with the true moving bed (TMB), is develo ped assuming multicomponent adsorption equilibria, axial dispersion flow an d the linear driving force approximation to describe the intraparticle mass transfer rate. The simulation package is used to predict the effect of ope rating variables on the process performance and to define the regions for e nantiomers separation. The influence of mass transfer resistance in the sep aration region is analyzed. A practical tool for choosing the better SMB op erating conditions as a function of the feed flow-rate is proposed. The exp erimental operation of a pilot unit of SMB, Licosep 12-26 (Novasep, France) , is carried out for the separation of enantiomers and illustrated with two systems: the bi-naphthol and the chiral epoxide enantiomers. Experimental results and model predictions are compared in terms of process performance and internal concentration profiles. (C) 2000 Elsevier Science B.V. All rig hts reserved.