Experimental Study of Continuous Separation of 1‐1^′‐Bi‐2‐Naphthol Enantiomers by an Eight‐Column Simulated Moving Bed System

Abstract

The separation of 1,1^′‐bi‐2‐naphthol racemic mixtures, using the eight‐column simulated fmoving‐bed (SMB) method with chiral columns of Pirkle D‐phenylglycine and each column length of 10 cm, was investigated experimentally in this study. A quick method was used to determine the optimal operating conditions for the SMB system. This was based on the “triangle theory,” and good separation conditions were found based on the experimental results of a series of SMB experiments conducted around the complete separation region of the “triangle theory.” The optimal operating conditions for each of the solvent composition systems (hexane/IPA = 90/10, 80/20, 70/30) were found, and the effect of solvent compositions on the SMB system performance was studied based on the above quick method. Good system performance (with purity and recovery higher than 97% and productivity higher than 0.44 mg/min of each isomer) was achieved using 80/20 hexane/IPA as eluent, which was found to be a suitable solvent composition for our SMB system.

Keywords:

• Enantiomers
• Chiral columns
• Simulated moving‐bed
• Solvent composition
• System performance
• Optimal operation

Acknowledgment

The authors wish to thank the National Science Council of the Republic of China for financial support under grants NSC 89‐2214‐E‐224‐007 and NSC 90‐2214‐E‐224‐003.