(493g) Design and Optimization of Double-Layer Simulated Moving Bed Chromatography for Continuous Ternary Separations

Chromatography has been widely applied for complex separation problems. Especially batch and recycle chromatography were used for ‘center-cut’ separation from multi-component mixtures, in which the target component migrates in the middle of the elution train. It was well known that continuous separation processes, such as simulated moving bed (SMB) chromatography, are efficient and cost-effective compared to batch or semi-continuous chromatographic separation processes in solving binary or pseudo-binary separation problems. However, even in this case it is still challenging to design a suitable continuous chromatographic process due to its operational and structural complexity.

Recently a new double-layer SMB process concept was introduced for solving the continuous ternary separation problem [1, 2]. Considering an operational similarity between SMB chromatography and fractional distillation, the dividing wall distillation process [3], which is nowadays well established and widely used for multi-component fractional distillation, was adopted for a novel continuous SMB configuration (Fig. 1). Based on a modified short-cut design, this new concept can provide improved performances compared to alternative ternary separation SMBs (SMB cascade [4] and integrated 8-zone SMB [5]) when the intermediate-retained component stands in the middle. The design and optimization of DL-SMB were performed using newly developed simulation tool. This tool uses various hold-up volume models, such as CST, simple lag, pipe, and packed column, and the connectivity can be built up flow-diagram basis. Including on-site monitoring techniques, dynamic optimization of DL-SMB was carried out to accomplish complete ternary separation for the model Langmuir isotherm system.

References:

[1] J. W. Lee, Ind. Eng. Chem. Res. 59, 9619 (2020).
[2] J. W. Lee, Ind. Eng. Chem. Res. 60, 8911 (2021).
[3] R. O. Wright, N. J. Elizabeth, U.S. Patent 2 471 134 A, (1949).
[4] P. C. Wankat, Ind. Eng. Chem. Res. 40, 6185 (2001).
[5] J. Nowak, D. Antos, A. Seidel-Morgenstern, J. Chromatogr. A 1253, 58 (2012).

Fig. 1. Schematic illustration of dividing-wall distillation (DW-Distillation) and double-layer SMB (DL-SMB).