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Optimal molecular design of ionic liquids for high-purity bioethanol production / Luz María Chávez-Islas in Industrial & engineering chemistry research, Vol. 50 N° 9 (Mai 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 9 (Mai 2011) . - pp. 5153-5168 Titre : Optimal molecular design of ionic liquids for high-purity bioethanol production Type de document : texte imprimé Auteurs : Luz María Chávez-Islas, Auteur ; Ruben Vasquez-Medrano, Auteur ; Antonio Flores-Tlacuahuac, Auteur Année de publication : 2011 Article en page(s) : pp. 5153-5168 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Production  High  purity  Ionic  liquid  Design Résumé : A mixed-integer nonlinear programming (MINLP) formulation for the molecular design optimization of ionic liquids (ILs) to recuperate ethanol with a purity of 99 mol % or greater from a E85 system (a mixture containing 85 and 15 mol% of ethanol and water, respectively) is presented. The reason why the ethanol/water separation is difficult is because of the azeotropic behavior of this system. Therefore, the IL is designed to feature water affinity such that it can break the ethanol/water azeotrope, allowing the high-purity separation to take place. The MINLP formulation is based on the development of a superstructure that contains a set of cations and anions, whose combination forms different kinds of ILs that have the potential to separate azeotropic systems such as the ethanol/water system. Because most of the ILs to be optimally designed are novel solvents, their physical and thermodynamic properties are estimated by group contribution methods. The optimization formulation is composed of a set of constraints featuring vapor―liquid equilibrium conditions as well as constraints dealing with structural and allowed cation-anion combinations. We assume that the separation will take place at atmospheric pressure. For the sake of simplicity, the optimal IL is first synthesized in a single separation stage, although the separation was also addressed using a reboiled absorption column. The results indicate that the optimally designed IL is capable of performing the required separation meeting the high-purity ethanol constraint. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24128639 [article] Optimal molecular design of ionic liquids for high-purity bioethanol production [texte imprimé] / Luz María Chávez-Islas, Auteur ; Ruben Vasquez-Medrano, Auteur ; Antonio Flores-Tlacuahuac, Auteur . - 2011 . - pp. 5153-5168. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 9 (Mai 2011) . - pp. 5153-5168 Mots-clés : Production  High  purity  Ionic  liquid  Design Résumé : A mixed-integer nonlinear programming (MINLP) formulation for the molecular design optimization of ionic liquids (ILs) to recuperate ethanol with a purity of 99 mol % or greater from a E85 system (a mixture containing 85 and 15 mol% of ethanol and water, respectively) is presented. The reason why the ethanol/water separation is difficult is because of the azeotropic behavior of this system. Therefore, the IL is designed to feature water affinity such that it can break the ethanol/water azeotrope, allowing the high-purity separation to take place. The MINLP formulation is based on the development of a superstructure that contains a set of cations and anions, whose combination forms different kinds of ILs that have the potential to separate azeotropic systems such as the ethanol/water system. Because most of the ILs to be optimally designed are novel solvents, their physical and thermodynamic properties are estimated by group contribution methods. The optimization formulation is composed of a set of constraints featuring vapor―liquid equilibrium conditions as well as constraints dealing with structural and allowed cation-anion combinations. We assume that the separation will take place at atmospheric pressure. For the sake of simplicity, the optimal IL is first synthesized in a single separation stage, although the separation was also addressed using a reboiled absorption column. The results indicate that the optimally designed IL is capable of performing the required separation meeting the high-purity ethanol constraint. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24128639

Optimal synthesis of a high purity bioethanol distillation column using ionic liquids / Luz María Chávez-Islas in Industrial & engineering chemistry research, Vol. 50 N° 9 (Mai 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 9 (Mai 2011) . - pp. 5175-5190 Titre : Optimal synthesis of a high purity bioethanol distillation column using ionic liquids Type de document : texte imprimé Auteurs : Luz María Chávez-Islas, Auteur ; Ruben Vasquez-Medrano, Auteur ; Antonio Flores-Tlacuahuac, Auteur Année de publication : 2011 Article en page(s) : pp. 5175-5190 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Ionic  liquid  Distillation  column  High  purity  Optimal  design Résumé : In this work, we address the optimal economical synthesis of an extractive distillation column for bioethanol purification, using ionic liquids as a type of solvent that can be designed to feature sustainable characteristics, such as low toxicity and low volatility, among other desirable properties. For the optimal synthesis of the separation scheme, we propose a mixed-integer nonlinear programming (MINLP) formulation, merged with disjunctive programming tools, to take care of modeling logical decisions [Yeomans and Grossmann, Ind. Eng. Chem. Res. 2000, 39, 1637―1648]. In a previous work [Chavez-Islas et al., submitted to Ind. Eng. Chem. Res.], we have addressed the design of a novel ionic liquid to separate the ethanol/water azeotropic system, up to high purities. The MLNLP synthesis of the distillation column considers the feed tray location, the number of trays, and the operating and design parameters as decision variables. Because the ionic liquid used in this work is a novel solvent, its physical and thermodynamic properties are yet not available. Therefore, the physical properties of the ionic liquid are estimated using group contribution methods. The MINLP formulation is based on the application of the MESH equations for conditional trays, to reduce the size of the nonlinear subproblems and increase the robustness of the optimization formulation. The MINLP problem was solved using the SBB solver embedded in GAMS. Using the proposed MINLP formulation, we attained ethanol purities as good as 99.9 mol %, and 90% of the ethanol presented in the feed stream was recovered. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24128641 [article] Optimal synthesis of a high purity bioethanol distillation column using ionic liquids [texte imprimé] / Luz María Chávez-Islas, Auteur ; Ruben Vasquez-Medrano, Auteur ; Antonio Flores-Tlacuahuac, Auteur . - 2011 . - pp. 5175-5190. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 9 (Mai 2011) . - pp. 5175-5190 Mots-clés : Ionic  liquid  Distillation  column  High  purity  Optimal  design Résumé : In this work, we address the optimal economical synthesis of an extractive distillation column for bioethanol purification, using ionic liquids as a type of solvent that can be designed to feature sustainable characteristics, such as low toxicity and low volatility, among other desirable properties. For the optimal synthesis of the separation scheme, we propose a mixed-integer nonlinear programming (MINLP) formulation, merged with disjunctive programming tools, to take care of modeling logical decisions [Yeomans and Grossmann, Ind. Eng. Chem. Res. 2000, 39, 1637―1648]. In a previous work [Chavez-Islas et al., submitted to Ind. Eng. Chem. Res.], we have addressed the design of a novel ionic liquid to separate the ethanol/water azeotropic system, up to high purities. The MLNLP synthesis of the distillation column considers the feed tray location, the number of trays, and the operating and design parameters as decision variables. Because the ionic liquid used in this work is a novel solvent, its physical and thermodynamic properties are yet not available. Therefore, the physical properties of the ionic liquid are estimated using group contribution methods. The MINLP formulation is based on the application of the MESH equations for conditional trays, to reduce the size of the nonlinear subproblems and increase the robustness of the optimization formulation. The MINLP problem was solved using the SBB solver embedded in GAMS. Using the proposed MINLP formulation, we attained ethanol purities as good as 99.9 mol %, and 90% of the ethanol presented in the feed stream was recovered. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24128641

Simultaneous optimal design of an extractive column and ionic liquid for the separation of bioethanol – water mixtures / Darinel Valencia-Marquez in Industrial & engineering chemistry research, Vol. 51 N° 17 (Mai 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 17 (Mai 2012) . - pp. 5866–5880 Titre : Simultaneous optimal design of an extractive column and ionic liquid for the separation of bioethanol – water mixtures Type de document : texte imprimé Auteurs : Darinel Valencia-Marquez, Auteur ; Antonio Flores-Tlacuahuac, Auteur ; Ruben Vasquez-Medrano, Auteur Année de publication : 2012 Article en page(s) : pp. 5866–5880 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Optimal  design  Bioethanol Résumé : Recently renewed interest in the optimal design of sustainable processing systems has emerged as consequence of pollution issues and global climate changes. The replacement of hazardous industrial solvents widely used for azeotropic separations is clearly a challenging research area for new products design. However, as important as product design is, the design of the optimal processing configuration where the azeotropic separation will take place is also a key issue. As a matter of fact, the strong interaction between product and process design indicates that better optimal processing conditions can be attained by solving both problems simultaneously rather than sequentially. In the present work, we take advantage of this natural interaction for the optimal simultaneous design of both ionic liquids and an extractive distillation column for the high purity separation of the ethanol/water azeotropic mixture for deploying ethanol as a biofuel. The problem is formulated as a steady-state disjunctive mixed-integer nonlinear programming (MINLP) problem. The results indicate that new green solvents constitute a good replacement for hazardous solvents. Because ionic liquids are expensive solvents, it is worth it to explore the deployment of advanced optimization tools for profit maximization of sustainable processing systems. Through the use of the proposed MINLP formulation, improved ethanol/water separation configurations deploying ionic liquids were attained. Because ethanol features high purity, it can be used for biofuel applications. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201726r [article] Simultaneous optimal design of an extractive column and ionic liquid for the separation of bioethanol – water mixtures [texte imprimé] / Darinel Valencia-Marquez, Auteur ; Antonio Flores-Tlacuahuac, Auteur ; Ruben Vasquez-Medrano, Auteur . - 2012 . - pp. 5866–5880. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 17 (Mai 2012) . - pp. 5866–5880 Mots-clés : Optimal  design  Bioethanol Résumé : Recently renewed interest in the optimal design of sustainable processing systems has emerged as consequence of pollution issues and global climate changes. The replacement of hazardous industrial solvents widely used for azeotropic separations is clearly a challenging research area for new products design. However, as important as product design is, the design of the optimal processing configuration where the azeotropic separation will take place is also a key issue. As a matter of fact, the strong interaction between product and process design indicates that better optimal processing conditions can be attained by solving both problems simultaneously rather than sequentially. In the present work, we take advantage of this natural interaction for the optimal simultaneous design of both ionic liquids and an extractive distillation column for the high purity separation of the ethanol/water azeotropic mixture for deploying ethanol as a biofuel. The problem is formulated as a steady-state disjunctive mixed-integer nonlinear programming (MINLP) problem. The results indicate that new green solvents constitute a good replacement for hazardous solvents. Because ionic liquids are expensive solvents, it is worth it to explore the deployment of advanced optimization tools for profit maximization of sustainable processing systems. Through the use of the proposed MINLP formulation, improved ethanol/water separation configurations deploying ionic liquids were attained. Because ethanol features high purity, it can be used for biofuel applications. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201726r