Documents disponibles écrits par cet auteur

Continuous-molecular targeting for integrated solvent and process design / Andre Bardow in Industrial & engineering chemistry research, Vol. 49 N° 6 (Mars 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 6 (Mars 2010) . - pp. 2834–2840 Titre : Continuous-molecular targeting for integrated solvent and process design Type de document : texte imprimé Auteurs : Andre Bardow, Auteur ; Klaas Steur, Auteur ; Joachim Gross, Auteur Année de publication : 2010 Article en page(s) : pp. 2834–2840 Note générale : Idustrial Chemistry Langues : Anglais (eng) Mots-clés : Molecular;  Solvent;  topology;  fluid  theory;  study; Résumé : An integrated design of processes and solvents is a prerequisite for achieving truly optimized solvent-based processes. However, solving the full integrated problem in a single optimization is usually not possible even for a predefined process topology due to the required discrete choices between molecular structures. Current approaches therefore mostly decompose the integrated problem into a process design and a molecular-design subproblem. The interaction between these subproblems is usually limited in practice, and a direct link between process performance and molecular characteristics of the solvent is not achieved. In this work, a novel methodology for the integrated process and molecular design problem is suggested where the discrete molecular decisions in the integrated design problem are circumvented by defining a hypothetical molecule. The approach is building upon a molecular-based thermodynamic model, where the parameters representing a molecule are treated as continuous. These parameters are optimized together with other process parameters, leading to an ideal hypothetical target molecule (represented by a set of parameters) and a corresponding optimized process. Only in a subsequent step, the parameters of the thermodynamic model representing the hypothetical molecule are mapped onto an existing optimal solvent. The method is illustrated for the design of solvents for carbon dioxide capture where the benefits of the integrated design approach are demonstrated. The perturbed-chain-polar-statistical-associating-fluid theory (PCP-SAFT) equation of state is used as a thermodynamic model. The framework introduced is generic in nature and thus applicable beyond the study of solvents to the integrated design of materials and processes in general. Note de contenu : Bibiogr. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901281w [article] Continuous-molecular targeting for integrated solvent and process design [texte imprimé] / Andre Bardow, Auteur ; Klaas Steur, Auteur ; Joachim Gross, Auteur . - 2010 . - pp. 2834–2840. Idustrial Chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 6 (Mars 2010) . - pp. 2834–2840 Mots-clés : Molecular;  Solvent;  topology;  fluid  theory;  study; Résumé : An integrated design of processes and solvents is a prerequisite for achieving truly optimized solvent-based processes. However, solving the full integrated problem in a single optimization is usually not possible even for a predefined process topology due to the required discrete choices between molecular structures. Current approaches therefore mostly decompose the integrated problem into a process design and a molecular-design subproblem. The interaction between these subproblems is usually limited in practice, and a direct link between process performance and molecular characteristics of the solvent is not achieved. In this work, a novel methodology for the integrated process and molecular design problem is suggested where the discrete molecular decisions in the integrated design problem are circumvented by defining a hypothetical molecule. The approach is building upon a molecular-based thermodynamic model, where the parameters representing a molecule are treated as continuous. These parameters are optimized together with other process parameters, leading to an ideal hypothetical target molecule (represented by a set of parameters) and a corresponding optimized process. Only in a subsequent step, the parameters of the thermodynamic model representing the hypothetical molecule are mapped onto an existing optimal solvent. The method is illustrated for the design of solvents for carbon dioxide capture where the benefits of the integrated design approach are demonstrated. The perturbed-chain-polar-statistical-associating-fluid theory (PCP-SAFT) equation of state is used as a thermodynamic model. The framework introduced is generic in nature and thus applicable beyond the study of solvents to the integrated design of materials and processes in general. Note de contenu : Bibiogr. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901281w

Efficient conversion of thermal energy into hydrogen / Leen V. van der Ham in Industrial & engineering chemistry research, Vol. 48 N° 18 (Septembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 18 (Septembre 2009) . - pp. 8500–8507 Titre : Efficient conversion of thermal energy into hydrogen : comparing two methods to reduce exergy losses in a sulfuric acid decomposition reactor Type de document : texte imprimé Auteurs : Leen V. van der Ham, Auteur ; Joachim Gross, Auteur ; Ad Verkooijen, Auteur Année de publication : 2010 Article en page(s) : pp. 8500–8507 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Thermal  energy  Hydrogen  Optimal  control  theory  Reactor  length Résumé : Two methods for increasing the exergy efficiency of thermochemical processes for the production of hydrogen from water and high temperature thermal energy are presented and compared. Increasing the exergy efficiency is equivalent to reducing the entropy production. Starting from a reference reactor for the decomposition of sulfuric acid, two new reactor designs are developed that both reduce the entropy production by 26%. The first design uses optimal control theory to obtain a more uniform distribution of the entropy production. As a result of this functional optimization we obtain optimal temperature profiles over the reactor length. This optimized design is found to perform the best, but it requires significant changes in the heating equipment in order to approximately realize the optimal temperature profiles. A second design is obtained by increasing the reactor length. This leads to a higher pressure drop and requires additional compressor duty. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801585e [article] Efficient conversion of thermal energy into hydrogen : comparing two methods to reduce exergy losses in a sulfuric acid decomposition reactor [texte imprimé] / Leen V. van der Ham, Auteur ; Joachim Gross, Auteur ; Ad Verkooijen, Auteur . - 2010 . - pp. 8500–8507. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 18 (Septembre 2009) . - pp. 8500–8507 Mots-clés : Thermal  energy  Hydrogen  Optimal  control  theory  Reactor  length Résumé : Two methods for increasing the exergy efficiency of thermochemical processes for the production of hydrogen from water and high temperature thermal energy are presented and compared. Increasing the exergy efficiency is equivalent to reducing the entropy production. Starting from a reference reactor for the decomposition of sulfuric acid, two new reactor designs are developed that both reduce the entropy production by 26%. The first design uses optimal control theory to obtain a more uniform distribution of the entropy production. As a result of this functional optimization we obtain optimal temperature profiles over the reactor length. This optimized design is found to perform the best, but it requires significant changes in the heating equipment in order to approximately realize the optimal temperature profiles. A second design is obtained by increasing the reactor length. This leads to a higher pressure drop and requires additional compressor duty. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801585e

Renormalization - group corrections to the perturbed - chain statistical associating fluid theory for binary mixtures / Xiaohua Tang 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. 9436–9444 Titre : Renormalization - group corrections to the perturbed - chain statistical associating fluid theory for binary mixtures Type de document : texte imprimé Auteurs : Xiaohua Tang, Auteur ; Joachim Gross, Auteur Année de publication : 2010 Article en page(s) : pp. 9436–9444 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Statistical  associating  fluid  theory Résumé : Classical fluid theories do not describe the long-range fluctuations that occur in the vicinity of a pure component or mixture’s critical point. The perturbed-chain statistical associating fluid theory (PC-SAFT) equation of state is extended with a renormalization group theory for mixtures. The theory accounts for the long-range density fluctuations and the results reduce to the results of the classical PC-SAFT equation of state away from the critical point. Two approximation methods, the isomorphic approximation and phase-space cell approximation, are used for the renormalization group corrections of mixtures. The two variants are evaluated by comparison to experimental vapor−liquid data for systems of alkanes, carbon dioxide and hydrogen sulfide. Overall, the considered implementation of the phase-space cell approximation is slightly superior to the isomorphic approximation for the mixtures investigated here. The phase-space cell approximation tends to overestimate the renormalization corrections for some cases but generally leads to good agreement with experimental data for binary mixtures. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100890d [article] Renormalization - group corrections to the perturbed - chain statistical associating fluid theory for binary mixtures [texte imprimé] / Xiaohua Tang, Auteur ; Joachim Gross, Auteur . - 2010 . - pp. 9436–9444. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9436–9444 Mots-clés : Statistical  associating  fluid  theory Résumé : Classical fluid theories do not describe the long-range fluctuations that occur in the vicinity of a pure component or mixture’s critical point. The perturbed-chain statistical associating fluid theory (PC-SAFT) equation of state is extended with a renormalization group theory for mixtures. The theory accounts for the long-range density fluctuations and the results reduce to the results of the classical PC-SAFT equation of state away from the critical point. Two approximation methods, the isomorphic approximation and phase-space cell approximation, are used for the renormalization group corrections of mixtures. The two variants are evaluated by comparison to experimental vapor−liquid data for systems of alkanes, carbon dioxide and hydrogen sulfide. Overall, the considered implementation of the phase-space cell approximation is slightly superior to the isomorphic approximation for the mixtures investigated here. The phase-space cell approximation tends to overestimate the renormalization corrections for some cases but generally leads to good agreement with experimental data for binary mixtures. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100890d