Three-column intermittent simulated moving bed chromatography: 2. Experimental implementation for the separation of Tröger's Base.

The three-column intermittent simulated moving bed (3C-ISMB) process has been presented in the first part of this series [1]. A theoretical comparative analysis of the new process to intermittent simulated moving bed (I-SMB) demonstrated successfully the potential of the 3C-ISMB technology. Particularly, 3C-ISMB was shown to substantially outperform I-SMB in terms of productivity whilst maintaining high purity specifications and without significantly sacrificing solvent consumption. Moreover, we demonstrated the applicability of Triangle Theory for 3C-ISMB design, which is an important advantage compared to other modified SMB schemes. In the present work we report on the experimental implementation of the 3C-ISMB technology demonstrating the simplicity of retrofitting an existing SMB or I-SMB plant. Moreover, we perform an experimental comparative analysis studying the well-known separation of Tröger's Base enantiomers in pure ethanol on Chiralpak AD™. In a comprehensive series of experimental runs, each examining three different modes of operation, applying total feed concentrations ranging from 5 g/l to 17.4 g/l, we assess and compare the separation performances of both conventional I-SMB and 3C-ISMB. This series of experiments successfully demonstrates that 3C-ISMB delivers the same high purity levels as conventional I-SMB whilst significantly outperforming the conventional process in terms of productivity; in fact an increase of more than 80% is achieved.