Documents disponibles écrits par cet auteur

Conceptual design and simulation tools applied to the evolutionary optimization of a bioethanol purification plant / Patricia M. Hoch in Industrial & engineering chemistry research, Vol. 47 N°19 (Octobre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 N°19 (Octobre 2008) . - p. 7381–7389 Titre : Conceptual design and simulation tools applied to the evolutionary optimization of a bioethanol purification plant Type de document : texte imprimé Auteurs : Patricia M. Hoch, Auteur ; Jose Espinosa, Auteur Année de publication : 2008 Article en page(s) : p. 7381–7389 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Bioethanol  purification  plant  Conceptual  model  Rigorous  models Résumé : We present an evolutionary optimization procedure applied to the design and simulation of the unit operations in a bioethanol purification plant. Conceptual and rigorous models are used; the first are utilized to determine initial values for design and operating variables, and then rigorous simulation is used to refine the results. The use of rigorous models allows for the elimination of simplifying assumptions, the interconnection of equipment, and the calculation of the operating and investment costs. Once an initial design of the purification plant is obtained, opportunities of improvement are easily recognized and then tested by performing the design and simulation steps until a cost-effective bioethanol purification plant is achieved. The methodology is applied to the purification process for a feed leaving the fermentation step of a conventional corn dry-grind processing facility producing 24 million L/year of ethanol and 19 million kg/year of distiller’s dry grains with solubles (DDGS). The feed to the purification plant (22 170 kg/h) is mainly composed by ethanol (10.80% w/w) and water (88.98% w/w) with traces of methanol (0.0226% w/w) and fusel (0.2009% w/w). Following the proposed approach, two initial designs of the whole purification plant using different technologies to break the azeotrope between ethanol and water are compared in terms of operating and investment costs. Savings in overall costs of about 32% are achieved by the alternative distillation/pervaporation in comparison with the option distillation/extractive distillation. Then, the membrane-based technology is adopted as the core of the purification process and a search for further improvements is performed. Four alternative designs were evaluated. In each case, the steam consumption of the evaporation sector is reduced by 1 300 kg/h by condensing the ethanol-rich side stream from the main rectification column in the first effect of the train. Finally, the option characterized by an ethanol composition in the ethanol-rich side stream of 91.24% w/w is selected as the quasi-optimal design because overall costs are reduced by 6.67% with respect to the base case and by 11.48% with respect to the worst case analyzed. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800450a [article] Conceptual design and simulation tools applied to the evolutionary optimization of a bioethanol purification plant [texte imprimé] / Patricia M. Hoch, Auteur ; Jose Espinosa, Auteur . - 2008 . - p. 7381–7389. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N°19 (Octobre 2008) . - p. 7381–7389 Mots-clés : Bioethanol  purification  plant  Conceptual  model  Rigorous  models Résumé : We present an evolutionary optimization procedure applied to the design and simulation of the unit operations in a bioethanol purification plant. Conceptual and rigorous models are used; the first are utilized to determine initial values for design and operating variables, and then rigorous simulation is used to refine the results. The use of rigorous models allows for the elimination of simplifying assumptions, the interconnection of equipment, and the calculation of the operating and investment costs. Once an initial design of the purification plant is obtained, opportunities of improvement are easily recognized and then tested by performing the design and simulation steps until a cost-effective bioethanol purification plant is achieved. The methodology is applied to the purification process for a feed leaving the fermentation step of a conventional corn dry-grind processing facility producing 24 million L/year of ethanol and 19 million kg/year of distiller’s dry grains with solubles (DDGS). The feed to the purification plant (22 170 kg/h) is mainly composed by ethanol (10.80% w/w) and water (88.98% w/w) with traces of methanol (0.0226% w/w) and fusel (0.2009% w/w). Following the proposed approach, two initial designs of the whole purification plant using different technologies to break the azeotrope between ethanol and water are compared in terms of operating and investment costs. Savings in overall costs of about 32% are achieved by the alternative distillation/pervaporation in comparison with the option distillation/extractive distillation. Then, the membrane-based technology is adopted as the core of the purification process and a search for further improvements is performed. Four alternative designs were evaluated. In each case, the steam consumption of the evaporation sector is reduced by 1 300 kg/h by condensing the ethanol-rich side stream from the main rectification column in the first effect of the train. Finally, the option characterized by an ethanol composition in the ethanol-rich side stream of 91.24% w/w is selected as the quasi-optimal design because overall costs are reduced by 6.67% with respect to the base case and by 11.48% with respect to the worst case analyzed. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800450a

Incorporating pinch distillation boundaries into the conceptual modeling of batch distillations / Karina Andrea Torres in Industrial & engineering chemistry research, Vol. 51 N° 47 (Novembre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 47 (Novembre 2012) . - pp. 15448-15455 Titre : Incorporating pinch distillation boundaries into the conceptual modeling of batch distillations : Ternary mixtures Type de document : texte imprimé Auteurs : Karina Andrea Torres, Auteur ; Jose Espinosa, Auteur Année de publication : 2013 Article en page(s) : pp. 15448-15455 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Ternary  mixture  Batchwise  Modeling  Distillation Résumé : This contribution explores the influence of curved unstable distillation boundaries on the performance of batch distillations in ternary mixtures and its incorporation into a conceptual modeling framework under the assumption of a batch rectifier with an infinite number of stages. First, the concept of preferred separation in batch distillation is presented. Calculation of "pitchfork" distillation boundaries is then determined using a robust predictor-corrector algorithm based on improved memory method with the purpose of estimating the maximum feasible distillate composition in the preferred separation line. Four highly nonideal systems are studied. Finally, the model is extended to allow simulation of the operation at different reflux policies. Results of a complete simulation performed with the enhanced conceptual model are shown for the system octane/2-ethoxyethanol/ ethylbenzene. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26679665 [article] Incorporating pinch distillation boundaries into the conceptual modeling of batch distillations : Ternary mixtures [texte imprimé] / Karina Andrea Torres, Auteur ; Jose Espinosa, Auteur . - 2013 . - pp. 15448-15455. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 47 (Novembre 2012) . - pp. 15448-15455 Mots-clés : Ternary  mixture  Batchwise  Modeling  Distillation Résumé : This contribution explores the influence of curved unstable distillation boundaries on the performance of batch distillations in ternary mixtures and its incorporation into a conceptual modeling framework under the assumption of a batch rectifier with an infinite number of stages. First, the concept of preferred separation in batch distillation is presented. Calculation of "pitchfork" distillation boundaries is then determined using a robust predictor-corrector algorithm based on improved memory method with the purpose of estimating the maximum feasible distillate composition in the preferred separation line. Four highly nonideal systems are studied. Finally, the model is extended to allow simulation of the operation at different reflux policies. Results of a complete simulation performed with the enhanced conceptual model are shown for the system octane/2-ethoxyethanol/ ethylbenzene. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26679665

Incorporating tangent pinch points into the conceptual modeling of batch distillations / Karina Andrea Torres in Industrial & engineering chemistry research, Vol. 48 N°2 (Janvier 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N°2 (Janvier 2009) . - p.857–869 Titre : Incorporating tangent pinch points into the conceptual modeling of batch distillations : ternary mixtures Type de document : texte imprimé Auteurs : Karina Andrea Torres, Auteur ; Jose Espinosa, Auteur Année de publication : 2009 Article en page(s) : p.857–869 Note générale : chemical engineering Langues : Anglais (eng) Mots-clés : Tangent  Pinch  Points--incorporating Résumé : This contribution explores the influence of tangent pinch points on the performance of batch distillations of highly nonideal ternary mixtures and its incorporation into a conceptual modeling framework under the assumption of a rectifier with an infinite number of stages. The maximum feasible distillate composition on the line of preferred separation and its corresponding limiting reflux ratio are first determined with the aid of bifurcation analysis of reversible distillation profiles. Then, the dependence of feasible distillate mole fractions on reflux ratios above the limiting one is calculated by solving a nonlinear equation system, which incorporates the tangency condition. Results obtained from the conceptual model for instantaneous column performance are in excellent agreement with those calculated from rigorous simulation. Two highly nonideal ternary mixtures are studied. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801169x [article] Incorporating tangent pinch points into the conceptual modeling of batch distillations : ternary mixtures [texte imprimé] / Karina Andrea Torres, Auteur ; Jose Espinosa, Auteur . - 2009 . - p.857–869. chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N°2 (Janvier 2009) . - p.857–869 Mots-clés : Tangent  Pinch  Points--incorporating Résumé : This contribution explores the influence of tangent pinch points on the performance of batch distillations of highly nonideal ternary mixtures and its incorporation into a conceptual modeling framework under the assumption of a rectifier with an infinite number of stages. The maximum feasible distillate composition on the line of preferred separation and its corresponding limiting reflux ratio are first determined with the aid of bifurcation analysis of reversible distillation profiles. Then, the dependence of feasible distillate mole fractions on reflux ratios above the limiting one is calculated by solving a nonlinear equation system, which incorporates the tangency condition. Results obtained from the conceptual model for instantaneous column performance are in excellent agreement with those calculated from rigorous simulation. Two highly nonideal ternary mixtures are studied. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801169x

Influence of tangent pinch points on the energy demand of batch distillations / Karina Andrea Torres in Industrial & engineering chemistry research, Vol. 50 N° 10 (Mai 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6260-6275 Titre : Influence of tangent pinch points on the energy demand of batch distillations : development of a conceptual model for binary mixtures Type de document : texte imprimé Auteurs : Karina Andrea Torres, Auteur ; Jose Espinosa, Auteur Année de publication : 2011 Article en page(s) : pp. 6260-6275 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Binary  mixture  Modeling  Distillation  Batchwise Résumé : This contribution explores the influence of tangent pinch points on the performance of batch distillations of highly nonideal binary mixtures and its incorporation into a conceptual modeling framework under the assumption of a rectifier with an infinite number of stages. First of all, the y-x diagram is divided into three regions taking into account both the inflection point (IP) in the phase diagram and the slope of the equilibrium curve at xD = 1. After that, limiting values for the reflux ratio and distillate composition; namely, r* and x*D are calculated for the instantaneous still composition xB with the aid of region-dependent algorithms, which incorporate the tangency condition in different ways. Finally, the instantaneous column performance is estimated taking into account the selected operation mode; i.e., constant reflux ratio or constant distillate composition. Applied to the mixture acetone-water, results for complete simulations are presented in terms of both rectification advance and operation time. A brief comparative study on the minimum energy demand required for a given separation as estimated from models with and without tangent pinches is also carried out. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158922 [article] Influence of tangent pinch points on the energy demand of batch distillations : development of a conceptual model for binary mixtures [texte imprimé] / Karina Andrea Torres, Auteur ; Jose Espinosa, Auteur . - 2011 . - pp. 6260-6275. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6260-6275 Mots-clés : Binary  mixture  Modeling  Distillation  Batchwise Résumé : This contribution explores the influence of tangent pinch points on the performance of batch distillations of highly nonideal binary mixtures and its incorporation into a conceptual modeling framework under the assumption of a rectifier with an infinite number of stages. First of all, the y-x diagram is divided into three regions taking into account both the inflection point (IP) in the phase diagram and the slope of the equilibrium curve at xD = 1. After that, limiting values for the reflux ratio and distillate composition; namely, r* and x*D are calculated for the instantaneous still composition xB with the aid of region-dependent algorithms, which incorporate the tangency condition in different ways. Finally, the instantaneous column performance is estimated taking into account the selected operation mode; i.e., constant reflux ratio or constant distillate composition. Applied to the mixture acetone-water, results for complete simulations are presented in terms of both rectification advance and operation time. A brief comparative study on the minimum energy demand required for a given separation as estimated from models with and without tangent pinches is also carried out. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158922