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 phases 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 dispersion flow for the liquid phase, linear driving force (LDF) approximation for intraparticle mass transfer rate and takes into account multicomponent adsorption equilibria. The SMB package allows the simulation of the pilot unit. The effect of operating variables (switching time, extract and feed how rates, section length) and number of mass transfer units on the SMB performance is analyzed. The SMB performance is characterized by purity, recovery, solvent consumption and adsorbent productivity. The package also allows the simulation of the dynamic evolution of internal profiles for the transient operation of a TMB. The operation of the SMB pilot unit was carried out for the separation of racemic mixtures of bi-naphthol enantiomers. Using a 8-column configuration purities as high as 94.5% of the more retained species in the extract and 98.9% of the less retained species in the raffinate were obtained. Copyright (C) 1996 Elsevier Science Ltd.