Documents disponibles écrits par cet auteur

Time - optimal control of dividing - wall distillation columns / Alexandru Woinaroschy in Industrial & engineering chemistry research, Vol. 49 N° 19 (Octobre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9195–9208 Titre : Time - optimal control of dividing - wall distillation columns Type de document : texte imprimé Auteurs : Alexandru Woinaroschy, Auteur ; Raluca Isopescu, Auteur Année de publication : 2010 Article en page(s) : pp. 9195–9208 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Optimal  control  Distillation Résumé : Time-optimal control of startup traditional distillation columns by iterative programming proposed by Woinaroschy for ideal [Ind. Eng. Chem. Res. 2008, 47, 4158] and nonideal mixtures [Ind. Eng. Chem. Res. 2009, 48, 3873] is extended to the case of dividing-wall distillation columns. The minimization of distillation startup time is performed by iterative dynamic programming employing randomly chosen candidates for admissible control. The control variables are the reflux ratio, the reboiler heat duty, and the side-draw flow rate. The dynamic distillation model proposed by the author in the previous papers is applied. Two illustrative case studies for the separation in a dividing-wall column with sieve trays and lateral downcomers are presented as follows: the separation of an ideal benzene−toluene−ethylbenzene ternary mixture and the separation of a nonideal methanol−ethanol−1-propanol mixture. In another case study, a conventional two-column system is presented in comparison to the dividing-wall column. As in the cases of traditional distillation columns, the startup time decrease and the corresponding reboiler energy savings are significant for each of the control variables. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100090p [article] Time - optimal control of dividing - wall distillation columns [texte imprimé] / Alexandru Woinaroschy, Auteur ; Raluca Isopescu, Auteur . - 2010 . - pp. 9195–9208. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9195–9208 Mots-clés : Optimal  control  Distillation Résumé : Time-optimal control of startup traditional distillation columns by iterative programming proposed by Woinaroschy for ideal [Ind. Eng. Chem. Res. 2008, 47, 4158] and nonideal mixtures [Ind. Eng. Chem. Res. 2009, 48, 3873] is extended to the case of dividing-wall distillation columns. The minimization of distillation startup time is performed by iterative dynamic programming employing randomly chosen candidates for admissible control. The control variables are the reflux ratio, the reboiler heat duty, and the side-draw flow rate. The dynamic distillation model proposed by the author in the previous papers is applied. Two illustrative case studies for the separation in a dividing-wall column with sieve trays and lateral downcomers are presented as follows: the separation of an ideal benzene−toluene−ethylbenzene ternary mixture and the separation of a nonideal methanol−ethanol−1-propanol mixture. In another case study, a conventional two-column system is presented in comparison to the dividing-wall column. As in the cases of traditional distillation columns, the startup time decrease and the corresponding reboiler energy savings are significant for each of the control variables. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100090p

Time-optimal control of startup distillation columns by iterative dynamic programming / Alexandru Woinaroschy in Industrial & engineering chemistry research, Vol. 47 n°12 (Juin 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°12 (Juin 2008) . - p. 4158–4169 Titre : Time-optimal control of startup distillation columns by iterative dynamic programming Type de document : texte imprimé Auteurs : Alexandru Woinaroschy, Auteur Année de publication : 2008 Article en page(s) : p. 4158–4169 Note générale : Bibliogr. p. 4169 Langues : Anglais (eng) Mots-clés : Distillation  startup  time;  Dynamic  programming;  Iterative  algebraic  equation Résumé : Iterative dynamic programming employing randomly chosen candidates for admissible control is applied to the minimization of distillation startup time. The solution of this high-dimensional problem was facilitated mainly by avoiding iterative algebraic equation solving inside a rigorous dynamic distillation model, thereby reducing the computation time. Several illustrative applications of various complexity degrees are presented. The control variables are the reflux ratio, the reboiler heat duty, or both. Both piecewise constant control and piecewise linear control strategies were employed. The decrease of the startup times and heat consumption is high, having an appreciable economic significance. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0713745 [article] Time-optimal control of startup distillation columns by iterative dynamic programming [texte imprimé] / Alexandru Woinaroschy, Auteur . - 2008 . - p. 4158–4169. Bibliogr. p. 4169 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°12 (Juin 2008) . - p. 4158–4169 Mots-clés : Distillation  startup  time;  Dynamic  programming;  Iterative  algebraic  equation Résumé : Iterative dynamic programming employing randomly chosen candidates for admissible control is applied to the minimization of distillation startup time. The solution of this high-dimensional problem was facilitated mainly by avoiding iterative algebraic equation solving inside a rigorous dynamic distillation model, thereby reducing the computation time. Several illustrative applications of various complexity degrees are presented. The control variables are the reflux ratio, the reboiler heat duty, or both. Both piecewise constant control and piecewise linear control strategies were employed. The decrease of the startup times and heat consumption is high, having an appreciable economic significance. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0713745

Time-optimal control of startup distillation of nonideal mixtures / Alexandru Woinaroschy in Industrial & engineering chemistry research, Vol. 48 N° 8 (Avril 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 8 (Avril 2009) . - pp. 3873–3879 Titre : Time-optimal control of startup distillation of nonideal mixtures Type de document : texte imprimé Auteurs : Alexandru Woinaroschy, Auteur Année de publication : 2009 Article en page(s) : pp. 3873–3879 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Startup  distillation  columns  Time-optimal  control  Nonideal  mixtures  Iterative  dynamic  programming Résumé : In this work, the time-optimal control of startup distillation columns by iterative programming proposed by Woinaroschy [ Ind. Eng. Chem. Res. 2008, 47, 4158.] is extended to the case of nonideal mixtures. The minimization of distillation startup time is performed by iterative dynamic programming employing randomly chosen candidates for admissible control. The control variables are the reflux ratio and/or the reboiler heat duty. The dynamic distillation model proposed by the author in the mentioned work is applied with a preliminary computation of suitable correlation relations for equilibrium constants. An illustrative application for separation of a propene−propane mixture at plant scale is presented. Because of the small relative volatility of this mixture and respective high reflux ratio, the decrease of the reboiler heat consumption corresponding to the minimization of the startup time is significant. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801490r [article] Time-optimal control of startup distillation of nonideal mixtures [texte imprimé] / Alexandru Woinaroschy, Auteur . - 2009 . - pp. 3873–3879. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 8 (Avril 2009) . - pp. 3873–3879 Mots-clés : Startup  distillation  columns  Time-optimal  control  Nonideal  mixtures  Iterative  dynamic  programming Résumé : In this work, the time-optimal control of startup distillation columns by iterative programming proposed by Woinaroschy [ Ind. Eng. Chem. Res. 2008, 47, 4158.] is extended to the case of nonideal mixtures. The minimization of distillation startup time is performed by iterative dynamic programming employing randomly chosen candidates for admissible control. The control variables are the reflux ratio and/or the reboiler heat duty. The dynamic distillation model proposed by the author in the mentioned work is applied with a preliminary computation of suitable correlation relations for equilibrium constants. An illustrative application for separation of a propene−propane mixture at plant scale is presented. Because of the small relative volatility of this mixture and respective high reflux ratio, the decrease of the reboiler heat consumption corresponding to the minimization of the startup time is significant. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801490r