Documents disponibles écrits par cet auteur

Bilevel optimizing control structure for a simulated moving bed process based on a reduced-order model using the cubic spline collocation method / Kiwoong Kim in Industrial & engineering chemistry research, Vol. 49 N° 8 (Avril 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3689–3699 Titre : Bilevel optimizing control structure for a simulated moving bed process based on a reduced-order model using the cubic spline collocation method Type de document : texte imprimé Auteurs : Kiwoong Kim, Auteur ; Kwang Soon Lee, Auteur ; Jay H. Lee, Auteur Année de publication : 2010 Article en page(s) : pp. 3689–3699 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Bilevel  Moving  Bed Résumé : A bilevel strategy for optimizing control of a simulated moving bed (SMB) process is proposed. In the lower level, repetitive model predictive control (RMPC) is used to regulate product purities; in the upper level, optimal feed/desorbent flow rates and the switching period are determined. Both levels employ a fundamental SMB model reduced to a set of nonlinear discrete-time dynamic equations using the cubic spline collocation method and exact discretization. For RMPC, the SMB model is linearized successively along the operating trajectories seen in the previous switching period. It is assumed that the flow rates can be varied within a switching period and the average product purities over each switching period can be measured albeit with a significant analysis delay. Numerical studies using linear isotherms showed that the proposed strategy is successful at driving the process to the intended optimum and maintaining it there while robustly regulating the product purities despite various uncertainties. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901121y [article] Bilevel optimizing control structure for a simulated moving bed process based on a reduced-order model using the cubic spline collocation method [texte imprimé] / Kiwoong Kim, Auteur ; Kwang Soon Lee, Auteur ; Jay H. Lee, Auteur . - 2010 . - pp. 3689–3699. Industrial Chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3689–3699 Mots-clés : Bilevel  Moving  Bed Résumé : A bilevel strategy for optimizing control of a simulated moving bed (SMB) process is proposed. In the lower level, repetitive model predictive control (RMPC) is used to regulate product purities; in the upper level, optimal feed/desorbent flow rates and the switching period are determined. Both levels employ a fundamental SMB model reduced to a set of nonlinear discrete-time dynamic equations using the cubic spline collocation method and exact discretization. For RMPC, the SMB model is linearized successively along the operating trajectories seen in the previous switching period. It is assumed that the flow rates can be varied within a switching period and the average product purities over each switching period can be measured albeit with a significant analysis delay. Numerical studies using linear isotherms showed that the proposed strategy is successful at driving the process to the intended optimum and maintaining it there while robustly regulating the product purities despite various uncertainties. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901121y

Experimental verification of bilevel optimizing control for SMB technology / Kiwoong Kim in Industrial & engineering chemistry research, Vol. 49 N° 18 (Septembre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 18 (Septembre 2010) . - pp. 8593–8600 Titre : Experimental verification of bilevel optimizing control for SMB technology Type de document : texte imprimé Auteurs : Kiwoong Kim, Auteur ; Jin-Il Kim, Auteur ; Huiyong Kim, Auteur Année de publication : 2010 Article en page(s) : pp. 8593–8600 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Optimizing  control  technique Résumé : An experimental study has been conducted to evaluate the bilevel optimizing control technique for simulated moving beds (SMBs) that was proposed in a previous article (Kim et al. Ind. Eng. Chem. Res. 2010, 49, 3689−3699). Off-line optimization provides optimum time-varying flow rates for feed and desorbent in the upper level, and repetitive model-based predictive control (RMPC) is performed for regulation of the extract and raffinate purities in the lower level. Experiments have been carried out in a four-zone SMB system packed with Dow 50WX4 400-mesh resin to separate l-ribose and l-arabinose at 99.7 vol% from their mixture dissolved in water. The optimizing control technique was implemented just as in the numerical study in the previous work, except for some minor customization. In the experiments, RMPC revealed quite satisfactory tracking and disturbance rejection performance. Optimization resulted in a 45% increase in productivity and a 12% decrease in desorbent consumption from an arbitrary initial point, and the cascaded RMPC law tightly maintained the product purities at their set points by effectively compensating the changes in the feed and desorbent flow rates. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1000218 [article] Experimental verification of bilevel optimizing control for SMB technology [texte imprimé] / Kiwoong Kim, Auteur ; Jin-Il Kim, Auteur ; Huiyong Kim, Auteur . - 2010 . - pp. 8593–8600. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 18 (Septembre 2010) . - pp. 8593–8600 Mots-clés : Optimizing  control  technique Résumé : An experimental study has been conducted to evaluate the bilevel optimizing control technique for simulated moving beds (SMBs) that was proposed in a previous article (Kim et al. Ind. Eng. Chem. Res. 2010, 49, 3689−3699). Off-line optimization provides optimum time-varying flow rates for feed and desorbent in the upper level, and repetitive model-based predictive control (RMPC) is performed for regulation of the extract and raffinate purities in the lower level. Experiments have been carried out in a four-zone SMB system packed with Dow 50WX4 400-mesh resin to separate l-ribose and l-arabinose at 99.7 vol% from their mixture dissolved in water. The optimizing control technique was implemented just as in the numerical study in the previous work, except for some minor customization. In the experiments, RMPC revealed quite satisfactory tracking and disturbance rejection performance. Optimization resulted in a 45% increase in productivity and a 12% decrease in desorbent consumption from an arbitrary initial point, and the cascaded RMPC law tightly maintained the product purities at their set points by effectively compensating the changes in the feed and desorbent flow rates. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1000218