title: Bi-level optimizing control of a simulated moving bed process with nonlinear adsorption isotherms.
abstract: 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.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Sogang University, 1 Shinsoodong, Mapogu, Seoul 121-742, South Korea.
authors.forename: Kiwoong
authors.initials: K
authors.lastname: Kim
authors.forename: Jin-Il
authors.initials: JI
authors.lastname: Kim
authors.forename: Hyukmin
authors.initials: H
authors.lastname: Park
authors.forename: Yoon-Mo
authors.initials: YM
authors.lastname: Koo
authors.forename: Kwang Soon
authors.initials: KS
authors.lastname: Lee
mesh_terms: D000327:Adsorption; D001089:Arabinose / Q000737:chemistry* / Q000302:isolation & purification; D002853:Chromatography, Liquid / Q000295:instrumentation*; D007700:Kinetics; D008962:Models, Theoretical; D012117:Resins, Synthetic / Q000737:chemistry; D012266:Ribose / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D012117:Resins, Synthetic; D012266:Ribose; D001089:Arabinose