Department of Chemical and Biomolecular Engineering, Sogang University, 1 Shinsoodong, Mapogu, Seoul 121-742, South Korea.
J Chromatogr A. 2011 Sep 23;1218(38):6843-7. doi: 10.1016/j.chroma.2011.07.079. Epub 2011 Jul 30.
A bi-level optimizing control scheme originally proposed for a simulated moving bed (SMB) with linear isotherms has been extended to an SMB with nonlinear isotherms. Cyclic steady state optimization is performed in the upper level to determine the optimum switching period and time-varying feed/desorbent flow rates, and repetitive model predictive control is run in the lower level for purity regulation, taking the decision variables from the upper level as feed-forward information. Experimental as well as numerical study for an SMB process separating a high-concentration mixture of aqueous L-ribose and L-arabinose solutions showed that the proposed scheme performs satisfactorily against various disturbances. In contrast, an alternative scheme based on an SMB model with linear isotherms showed a limitation in the control performance; this scheme was apt to fail in purity regulation.
一个原本针对具有线性等温线的模拟移动床 (SMB) 提出的双层优化控制方案已扩展到具有非线性等温线的 SMB。在上层进行循环稳态优化以确定最佳切换周期和时变进料/解吸剂流速，在下层进行重复模型预测控制以进行纯度调节，将上层的决策变量作为前馈信息。用于分离高浓度水溶液 L-核糖和 L-阿拉伯糖混合物的 SMB 过程的实验和数值研究表明，该方案在各种干扰下表现令人满意。相比之下，基于具有线性等温线的 SMB 模型的替代方案在控制性能方面表现出局限性；该方案在纯度调节方面容易失败。
