Documents disponibles écrits par cet auteur

Active constraint regions for optimal operation of chemical processes / Magnus G. Jacobsen in Industrial & engineering chemistry research, Vol. 50 N° 19 (Octobre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 19 (Octobre 2011) . - pp. 11226–11236 Titre : Active constraint regions for optimal operation of chemical processes Type de document : texte imprimé Auteurs : Magnus G. Jacobsen, Auteur ; Sigurd Skogestad, Auteur Année de publication : 2011 Article en page(s) : pp. 11226–11236 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Optimal  operation  Chemical  processes Résumé : When designing the control structure of a chemical plant, with optimal operation and control in mind, it is important to know how the active set of constraints changes with disturbances.The generation of optimal active constraints regions using optimization generally is very time-consuming, and this paper discusses how to use process knowledge to minimize the need for numerical calculations—that is, minimize the number of optimization problems that must be solved. We consider the case of two disturbances, as this can be nicely represented graphically. In this paper, we study economically optimal operation of a reactor–separator–recycle process and show how the set of active constraints changes with feed flow rate and energy cost as disturbances. We also identify the economical and physical bottleneck of the process. For this case study process, we find five distinct regions with different active sets. This illustrates that, even for simple cases, the map of active constraint regions can be quite complex. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2012196?mi=uytze9&af=R&pageSize=20&searchT [...] [article] Active constraint regions for optimal operation of chemical processes [texte imprimé] / Magnus G. Jacobsen, Auteur ; Sigurd Skogestad, Auteur . - 2011 . - pp. 11226–11236. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 19 (Octobre 2011) . - pp. 11226–11236 Mots-clés : Optimal  operation  Chemical  processes Résumé : When designing the control structure of a chemical plant, with optimal operation and control in mind, it is important to know how the active set of constraints changes with disturbances.The generation of optimal active constraints regions using optimization generally is very time-consuming, and this paper discusses how to use process knowledge to minimize the need for numerical calculations—that is, minimize the number of optimization problems that must be solved. We consider the case of two disturbances, as this can be nicely represented graphically. In this paper, we study economically optimal operation of a reactor–separator–recycle process and show how the set of active constraints changes with feed flow rate and energy cost as disturbances. We also identify the economical and physical bottleneck of the process. For this case study process, we find five distinct regions with different active sets. This illustrates that, even for simple cases, the map of active constraint regions can be quite complex. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2012196?mi=uytze9&af=R&pageSize=20&searchT [...]

Application of balanced truncation to nonlinear systems / Ivan Dones in Industrial & engineering chemistry research, Vol. 50 N° 17 (Septembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 17 (Septembre 2011) . - pp. 10093-10101 Titre : Application of balanced truncation to nonlinear systems Type de document : texte imprimé Auteurs : Ivan Dones, Auteur ; Sigurd Skogestad, Auteur ; Heinz A. Preisig, Auteur Année de publication : 2011 Article en page(s) : pp. 10093-10101 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Non  linear  system Résumé : The balanced truncation method for reducing the size of a model was originally developed for linear systems. When extended to nonlinear systems, some considerations must be faced. First of all, the calculation of the balancing transformation matrix is not unique. This may results in nonphysical values for the reconstructed states, which may lead to failure, for example, in thermodynamic routines. To reduce this problem, it is recommended to include all the states in the balancing outputs. To further reduce the effect of nonlinearties in the original model, it is recommended to use a linearizing static transformation of the states, if available. In this paper, distillation column models are used as a case study, and, in this case, a logarithmic transformation of the compositions is beneficial. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24483654 [article] Application of balanced truncation to nonlinear systems [texte imprimé] / Ivan Dones, Auteur ; Sigurd Skogestad, Auteur ; Heinz A. Preisig, Auteur . - 2011 . - pp. 10093-10101. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 17 (Septembre 2011) . - pp. 10093-10101 Mots-clés : Non  linear  system Résumé : The balanced truncation method for reducing the size of a model was originally developed for linear systems. When extended to nonlinear systems, some considerations must be faced. First of all, the calculation of the balancing transformation matrix is not unique. This may results in nonphysical values for the reconstructed states, which may lead to failure, for example, in thermodynamic routines. To reduce this problem, it is recommended to include all the states in the balancing outputs. To further reduce the effect of nonlinearties in the original model, it is recommended to use a linearizing static transformation of the states, if available. In this paper, distillation column models are used as a case study, and, in this case, a logarithmic transformation of the compositions is beneficial. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24483654

Consistent inventory control / Elvira Marie B. Aske in Industrial & engineering chemistry research, Vol. 48 N° 24 (Décembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 24 (Décembre 2009) . - pp. 10892–10902 Titre : Consistent inventory control Type de document : texte imprimé Auteurs : Elvira Marie B. Aske, Auteur ; Sigurd Skogestad, Auteur Année de publication : 2010 Article en page(s) : pp. 10892–10902 Note générale : Industrail chemistry Langues : Anglais (eng) Mots-clés : Consistent--Inventory--Control Résumé : Inventory or material balance control is an important part of process control. In the literature, many rules have been proposed to help in designing such systems, but their justification is often unclear. The main contribution of this paper is to propose the more general local-consistency rule for evaluating inventory control systems. Consistency means that the steady-state mass balances (total, component, and phase) for the individual units and the overall plant are satisfied. In addition, local consistency is a desired property, meaning that the local mass balances are satisfied with local inventory loops only. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801603j [article] Consistent inventory control [texte imprimé] / Elvira Marie B. Aske, Auteur ; Sigurd Skogestad, Auteur . - 2010 . - pp. 10892–10902. Industrail chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 24 (Décembre 2009) . - pp. 10892–10902 Mots-clés : Consistent--Inventory--Control Résumé : Inventory or material balance control is an important part of process control. In the literature, many rules have been proposed to help in designing such systems, but their justification is often unclear. The main contribution of this paper is to propose the more general local-consistency rule for evaluating inventory control systems. Consistency means that the steady-state mass balances (total, component, and phase) for the individual units and the overall plant are satisfied. In addition, local consistency is a desired property, meaning that the local mass balances are satisfied with local inventory loops only. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801603j

Consistent inventory control / Elvira Marie B. Aske in Industrial & engineering chemistry research, Vol. 48 N° 24 (Décembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 24 (Décembre 2009) . - pp. 10892–10902 Titre : Consistent inventory control Type de document : texte imprimé Auteurs : Elvira Marie B. Aske, Auteur ; Sigurd Skogestad, Auteur Année de publication : 2010 Article en page(s) : pp. 10892–10902 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Material  balance  control Résumé : Inventory or material balance control is an important part of process control. In the literature, many rules have been proposed to help in designing such systems, but their justification is often unclear. The main contribution of this paper is to propose the more general local-consistency rule for evaluating inventory control systems. Consistency means that the steady-state mass balances (total, component, and phase) for the individual units and the overall plant are satisfied. In addition, local consistency is a desired property, meaning that the local mass balances are satisfied with local inventory loops only. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801603j [article] Consistent inventory control [texte imprimé] / Elvira Marie B. Aske, Auteur ; Sigurd Skogestad, Auteur . - 2010 . - pp. 10892–10902. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 24 (Décembre 2009) . - pp. 10892–10902 Mots-clés : Material  balance  control Résumé : Inventory or material balance control is an important part of process control. In the literature, many rules have been proposed to help in designing such systems, but their justification is often unclear. The main contribution of this paper is to propose the more general local-consistency rule for evaluating inventory control systems. Consistency means that the steady-state mass balances (total, component, and phase) for the individual units and the overall plant are satisfied. In addition, local consistency is a desired property, meaning that the local mass balances are satisfied with local inventory loops only. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801603j

Experimental and theoretical studies on the start-up operation of a multivessel batch distillation column / Sven Gruetzmann in Industrial & engineering chemistry research, Vol. 48 N° 11 (Juin 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 11 (Juin 2009) . - pp. 5336–5343 Titre : Experimental and theoretical studies on the start-up operation of a multivessel batch distillation column Type de document : texte imprimé Auteurs : Sven Gruetzmann, Auteur ; Georg Fieg, Auteur ; Sigurd Skogestad, Auteur Année de publication : 2009 Article en page(s) : pp. 5336–5343 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Multivessel  batch  distillation  Reflux  strategy  Start-up  period Résumé : Multivessel batch distillation is a promising alternative to conventional batch distillation. Earlier studies proved the feasibility of temperature control in a closed operation mode, that is, when no product is removed until the end of the process. In this article, the influence of the reflux strategy during the initial start-up period is investigated in detail. This is a very important task in terms of the development of automation procedures in an industrial realization. The work is divided into three main parts. First, a rigorous dynamic model is introduced to describe the behavior of a multivessel batch distillation during start-up. Then, two experiments carried out on a laboratory scale column were chosen to validate the model. Finally, a sensitivity study is presented observing composition response while changing the reflux strategy. The results show that the process can be improved by applying a high reflux ratio and establishing the hydraulics as soon as possible. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800962b [article] Experimental and theoretical studies on the start-up operation of a multivessel batch distillation column [texte imprimé] / Sven Gruetzmann, Auteur ; Georg Fieg, Auteur ; Sigurd Skogestad, Auteur . - 2009 . - pp. 5336–5343. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 11 (Juin 2009) . - pp. 5336–5343 Mots-clés : Multivessel  batch  distillation  Reflux  strategy  Start-up  period Résumé : Multivessel batch distillation is a promising alternative to conventional batch distillation. Earlier studies proved the feasibility of temperature control in a closed operation mode, that is, when no product is removed until the end of the process. In this article, the influence of the reflux strategy during the initial start-up period is investigated in detail. This is a very important task in terms of the development of automation procedures in an industrial realization. The work is divided into three main parts. First, a rigorous dynamic model is introduced to describe the behavior of a multivessel batch distillation during start-up. Then, two experiments carried out on a laboratory scale column were chosen to validate the model. Finally, a sensitivity study is presented observing composition response while changing the reflux strategy. The results show that the process can be improved by applying a high reflux ratio and establishing the hydraulics as soon as possible. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800962b

Experimental and theoretical studies on the start-up operation of a multivessel batch distillation column / Sven Gruetzmann in Industrial & engineering chemistry research, Vol. 48 N° 11 (Juin 2009) 

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A Natural Gas to Liquids Process Model for Optimal Operation / Mehdi Panahi in Industrial & engineering chemistry research, Vol. 51 N° 1 (Janvier 2012) 

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Selection of controlled variables for a natural gas to liquids process / Mehdi Panahi in Industrial & engineering chemistry research, Vol. 51 N° 30 (Août 2012) 

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Selection of controlled variables / Eduardo Shigueo Hori in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008) 

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Steady-state operational degrees of freedom with application to refrigeration cycles / Jørgen Bauck Jensen in Industrial & engineering chemistry research, Vol. 48 N° 14 (Juillet 2009) 

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