Finite Horizon Optimizing Control of Advanced SMB Chromatographic Processes

Authors:	Toumi A., University of Dortmund, Germany Diehl M., University of Heidelberg, Germany Engell S., University of Dortmund, Germany Bock H.G., University of Heidelberg, Germany Schloeder J.P., University of Heidelberg, Germany
Topic:	6.1 Chemical Process Control
Session:	Process Optimization and Predictive Control
Keywords:	Optimizing control, NMPC, Chromatography, Simulated Moving Bed, \\\\VARICOL, PowerFeed, Direct multiple shooting,Nonlinear optimization

Abstract

Simulated Moving Bed (SMB) chromatography is attracting increasingattention for complex separation tasks. Chromatography is the methodof choice in different fields (e.g. in the production of finechemicals and pharmaceuticals) if the components have physicochemicalproperties which differ little or are thermally unstable. In thesecases, standard separation techniques as, e.g. distillation orextraction, are not applicable.Control of SMB processes is a challenging task, as these processesexhibit a strongly nonlinear behavior and are of hybrid and periodicnature. In this contribution, we investigate the optimizing control ofthe new advanced SMB-like processes VARICOL and PowerFeed. The onlineoptimization is based on a full rigorous process model. An efficientnumerical approach for the solution of the control problem isdescribed and the control performance is demonstrated in simulationsof a benchmark enantiomer separation.