Journal of Zhejiang University SCIENCE A
ISSN 1673-565X(Print), 1862-1775(Online), Monthly

2009   Vol. 10   No. 5   p. 758~766

Simulated moving bed separation of tocopherol homologues: simulation and experiments

Yu-bin LÜ^†1,2, Bao-gen SU^†‡1, Yi-wen YANG¹, Qi-long REN¹, Ping-dong WU¹

(¹National Laboratory of Secondary Resources Chemical Engineering, Zhejiang University, Hangzhou 310027, China)
(²Hangzhou Zhongmei Huadong Pharmaceutical Co., Ltd., Hangzhou 310011, China)
^‡ Corresponding Author
^†E-mail: lvyubin2001@zju.edu.cn; subg@zju.edu.cn
Received June 1, 2008; revision accepted Nov. 11, 2008; Crosschecked Feb. 25, 2009

Abstract: Chromatograms of tocopherol homologues were obtained by a column of analytical size (inner diameter (ID) 0.46 cm cm×10 cm) packed with silica gel. Adsorption isotherms and film mass-transfer coefficient were estimated from the chromatograms by using a general rate model, which considers axial dispersion, external mass-transfer and intraparticle diffusion. Based on the obtained isotherms and mass-transfer coefficient, the separation process of tocopherol homologues on simulated moving bed (SMB) was simulated using the same model. According to the simulated results, a mixture of α-, γ-, δ-tocopherols and other impurities was separated on an SMB equipment. The SMB equipment was composed of 8 columns of ID 2 cm×10 cm, with 2 columns in each section. The solid phase was silica gel, and the mobile phase was n-hexane/2-propanol (99/1 by volume). γ- and δ-tocopherols of purity greater than 98% were obtained with recovery greater than 98%. The effects of operating conditions (flow rates and switching time) on the performance of SMB were studied by both simulation and experiments. It was found that all the simulation results were quite close to the experimental results. We conclude that process development and optimization of operating conditions of SMB by simulation are feasible.

Key words: Simulated moving bed (SMB), Separation, Modeling, Simulation, Tocopherol homologues
doi:10.1631/jzus.A0850108             CLC number: TQ028.3

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