SEPARATION OF 1,1'-BI-2-NAPHTHOL ENANTIOMERS BY CONTINUOUS CHROMATOGRAPHY IN SIMULATED MOVING-BED

The chromatographic separation of 1,1'-bi-2-naphthol enantiomers with 3,5-dinitrobenzoyl phenylglycine bonded to silica gel stationary phase s is studied. Continuous chromatography in simulated moving bed (SMB) is analyzed by modeling, simulation and operation of a SMB pilot unit Licosep 12-26 from Separex (France). A model for the prediction of the cyclic steady-state performance of the SMB is developed based on the analogy with the true moving bed (TMB). The model assumes axial disper sion flow for the liquid phase, linear driving force (LDF) approximati on for intraparticle mass transfer rate and takes into account multico mponent adsorption equilibria. The SMB package allows the simulation o f the pilot unit. The effect of operating variables (switching time, e xtract and feed how rates, section length) and number of mass transfer units on the SMB performance is analyzed. The SMB performance is char acterized by purity, recovery, solvent consumption and adsorbent produ ctivity. The package also allows the simulation of the dynamic evoluti on of internal profiles for the transient operation of a TMB. The oper ation of the SMB pilot unit was carried out for the separation of race mic mixtures of bi-naphthol enantiomers. Using a 8-column configuratio n purities as high as 94.5% of the more retained species in the extrac t and 98.9% of the less retained species in the raffinate were obtaine d. Copyright (C) 1996 Elsevier Science Ltd.