Documents disponibles écrits par cet auteur

Generalized disjunctive programming for synthesis of rice drying processes / Abdunnaser Younes in Industrial & engineering chemistry research, Vol. 49 N° 5 (Mars 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 5 (Mars 2010) . - pp. 2312–2325 Titre : Generalized disjunctive programming for synthesis of rice drying processes Type de document : texte imprimé Auteurs : Abdunnaser Younes, Auteur ; Wongphaka Wongrat, Auteur ; Ali Elkamel, Auteur Année de publication : 2010 Article en page(s) : pp. 2312–2325 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Rice  drying;  Generalized  disjunctive  programming Résumé : Rice drying synthesis is an essential operation that has to be done carefully and cost-effectively. Fast drying can cause fissuring, which lowers the market value of the rice grains. Multipass drying systems are therefore used to bring the moisture content to desired levels gradually. To determine the best configuration of units and their corresponding operating conditions that maximize rice quality and minimize energy consumption, empirical models are used. However, empirical models have limited ranges of validity. Moreover, different mathematical models are possible for the same synthesis problem. This paper proposes a generalized disjunctive programming (GDP) framework for the synthesis problem of rice drying in order to increase the overall range of applicability of the empirical models and establish a consistent solution strategy. The proposed framework is investigated and tested on several case studies. Different drying strategies resulted from solving the synthesis problem with different empirical models, providing us with a broader vision of the mechanism of rice drying processes. The results indicate that the GDP framework can facilitate the modeling of the synthesis problem and increase the efficiency of optimization algorithms. Note de contenu : Bibliogr. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901190v [article] Generalized disjunctive programming for synthesis of rice drying processes [texte imprimé] / Abdunnaser Younes, Auteur ; Wongphaka Wongrat, Auteur ; Ali Elkamel, Auteur . - 2010 . - pp. 2312–2325. Industrial Chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 5 (Mars 2010) . - pp. 2312–2325 Mots-clés : Rice  drying;  Generalized  disjunctive  programming Résumé : Rice drying synthesis is an essential operation that has to be done carefully and cost-effectively. Fast drying can cause fissuring, which lowers the market value of the rice grains. Multipass drying systems are therefore used to bring the moisture content to desired levels gradually. To determine the best configuration of units and their corresponding operating conditions that maximize rice quality and minimize energy consumption, empirical models are used. However, empirical models have limited ranges of validity. Moreover, different mathematical models are possible for the same synthesis problem. This paper proposes a generalized disjunctive programming (GDP) framework for the synthesis problem of rice drying in order to increase the overall range of applicability of the empirical models and establish a consistent solution strategy. The proposed framework is investigated and tested on several case studies. Different drying strategies resulted from solving the synthesis problem with different empirical models, providing us with a broader vision of the mechanism of rice drying processes. The results indicate that the GDP framework can facilitate the modeling of the synthesis problem and increase the efficiency of optimization algorithms. Note de contenu : Bibliogr. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901190v

Integrated energy optimization model for oil sands operations / Alberto Betancourt-Torcat in Industrial & engineering chemistry research, Vol. 50 N° 22 (Novembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 22 (Novembre 2011) . - pp. 12641-12663 Titre : Integrated energy optimization model for oil sands operations Type de document : texte imprimé Auteurs : Alberto Betancourt-Torcat, Auteur ; Gloria Gutierrez, Auteur ; Ali Elkamel, Auteur Année de publication : 2012 Article en page(s) : pp. 12641-12663 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Tar  sand  Modeling  Optimization Résumé : This article presents a new energy model that predicts the energy infrastructure required to maintain oil production in the Canadian Oil Sands operation at minimum cost. Previous studies in this area have focused on the energy infrastructure for fixed energy demands (i.e., the production schemes that produce synthetic crude oil (SCO) and commercial diluted bitumen remained fixed in the calculation of the optimal infrastructure). The key novelty of this work is that the model searches simultaneously for the most suitable set of oil production schemes and the corresponding energy infrastructures that satisfy the total production demands under environmental constraints, namely, CO2 emissions targets. The proposed modeling tool was validated using historical data and previous simulations of the Canadian Oil Sands operation in 2003. Likewise, the proposed model was used to study the 2020 Canadian Oil Sands operations under three different production scenarios. Also, the 2020 case study was used to show the effect of CO2 capture constraints on the oil production schemes and the energy producers. The results show that the proposed model is a practical tool for determining the production costs of the Canadian Oil Sands operations, evaluating future production schemes and energy demand scenarios, and identifying the key parameters that affect Canadian Oil Sands operations. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24745740 [article] Integrated energy optimization model for oil sands operations [texte imprimé] / Alberto Betancourt-Torcat, Auteur ; Gloria Gutierrez, Auteur ; Ali Elkamel, Auteur . - 2012 . - pp. 12641-12663. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 22 (Novembre 2011) . - pp. 12641-12663 Mots-clés : Tar  sand  Modeling  Optimization Résumé : This article presents a new energy model that predicts the energy infrastructure required to maintain oil production in the Canadian Oil Sands operation at minimum cost. Previous studies in this area have focused on the energy infrastructure for fixed energy demands (i.e., the production schemes that produce synthetic crude oil (SCO) and commercial diluted bitumen remained fixed in the calculation of the optimal infrastructure). The key novelty of this work is that the model searches simultaneously for the most suitable set of oil production schemes and the corresponding energy infrastructures that satisfy the total production demands under environmental constraints, namely, CO2 emissions targets. The proposed modeling tool was validated using historical data and previous simulations of the Canadian Oil Sands operation in 2003. Likewise, the proposed model was used to study the 2020 Canadian Oil Sands operations under three different production scenarios. Also, the 2020 case study was used to show the effect of CO2 capture constraints on the oil production schemes and the energy producers. The results show that the proposed model is a practical tool for determining the production costs of the Canadian Oil Sands operations, evaluating future production schemes and energy demand scenarios, and identifying the key parameters that affect Canadian Oil Sands operations. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24745740

Multisite refinery and petrochemical network design / K. Al-Qahtani 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. 814–826 Titre : Multisite refinery and petrochemical network design : optimal integration and coordination Type de document : texte imprimé Auteurs : K. Al-Qahtani, Auteur ; Ali Elkamel, Auteur Année de publication : 2009 Article en page(s) : p. 814–826 Note générale : chemical engineering Langues : Anglais (eng) Mots-clés : Petrochemical  Network  Design: Résumé : This paper addresses the design of optimal integration and coordination of a refinery and petrochemical network to satisfy given chemical products demand. The refinery and petrochemical systems were modeled as a mixed-integer problem with the objective of minimizing the annualized cost over a given time horizon among the refineries and maximizing the added value of the petrochemical network. The main feature of the paper is the development of a methodology for simultaneous analysis of process network integration within a multisite refinery and petrochemical system. This approach provides appropriate planning across the petroleum refining and petrochemical industry and achieves an optimal production strategy by allowing appropriate trade-offs between the refinery and the downstream petrochemical markets. The performance of the proposed model was tested on industrial-scale examples of multiple refineries and a poly(vinyl chloride) (PVC) complex to illustrate the economic potential and trade-offs involved in the optimization of the network. The proposed methodology not only devises the integration network in the refineries and synthesizes the petrochemical industry, but also provides refinery expansion requirements, production levels, and blending levels. The use of mathematical programming on an enterprise-wide scale to address strategic decisions considering various process integration alternatives yields substantial benefits. These benefits of process integration materialize in terms of economic considerations and improvements in the understanding of the process interactions and systems limitations. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801001q [article] Multisite refinery and petrochemical network design : optimal integration and coordination [texte imprimé] / K. Al-Qahtani, Auteur ; Ali Elkamel, Auteur . - 2009 . - p. 814–826. chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N°2 (Janvier 2009) . - p. 814–826 Mots-clés : Petrochemical  Network  Design: Résumé : This paper addresses the design of optimal integration and coordination of a refinery and petrochemical network to satisfy given chemical products demand. The refinery and petrochemical systems were modeled as a mixed-integer problem with the objective of minimizing the annualized cost over a given time horizon among the refineries and maximizing the added value of the petrochemical network. The main feature of the paper is the development of a methodology for simultaneous analysis of process network integration within a multisite refinery and petrochemical system. This approach provides appropriate planning across the petroleum refining and petrochemical industry and achieves an optimal production strategy by allowing appropriate trade-offs between the refinery and the downstream petrochemical markets. The performance of the proposed model was tested on industrial-scale examples of multiple refineries and a poly(vinyl chloride) (PVC) complex to illustrate the economic potential and trade-offs involved in the optimization of the network. The proposed methodology not only devises the integration network in the refineries and synthesizes the petrochemical industry, but also provides refinery expansion requirements, production levels, and blending levels. The use of mathematical programming on an enterprise-wide scale to address strategic decisions considering various process integration alternatives yields substantial benefits. These benefits of process integration materialize in terms of economic considerations and improvements in the understanding of the process interactions and systems limitations. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801001q

Strategic planning of integrated multirefinery networks / Adriana Leiras in Industrial & engineering chemistry research, Vol. 49 N° 20 (Octobre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 20 (Octobre 2010) . - pp. 9970–9977 Titre : Strategic planning of integrated multirefinery networks : A robust optimization approach based on the degree of conservatism Type de document : texte imprimé Auteurs : Adriana Leiras, Auteur ; Ali Elkamel, Auteur ; Silvio Hamacher, Auteur Année de publication : 2011 Article en page(s) : pp. 9970–9977 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Optimization Résumé : This paper considers the problem of strategic planning under uncertainty for optimal integration and coordination of a multirefinery network. The deterministic model proposed by Al-Qahtani and Elkamel [Comput. Chem. Eng. 2008, 32, 2189−202] was extended to account for uncertainties in raw material costs and final product prices, as well as product demand. The robust optimization methodology of Bertsimas and Sim [Op. Res. 2004, 52, 35−53] was applied, which deals with uncertainty in a tractable manner and does not add complexity to the deterministic problem. An industrial-scale study illustrated the benefits of the integrated planning and demonstrated that the modeling of uncertainty in process parameters provides a more practical perspective of the refining industry. In addition, probability bounds of constraint violation were calculated to help decision makers select appropriate parameters to control solution robustness and evaluate trade-offs between conservatism and total profit. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100919z [article] Strategic planning of integrated multirefinery networks : A robust optimization approach based on the degree of conservatism [texte imprimé] / Adriana Leiras, Auteur ; Ali Elkamel, Auteur ; Silvio Hamacher, Auteur . - 2011 . - pp. 9970–9977. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 20 (Octobre 2010) . - pp. 9970–9977 Mots-clés : Optimization Résumé : This paper considers the problem of strategic planning under uncertainty for optimal integration and coordination of a multirefinery network. The deterministic model proposed by Al-Qahtani and Elkamel [Comput. Chem. Eng. 2008, 32, 2189−202] was extended to account for uncertainties in raw material costs and final product prices, as well as product demand. The robust optimization methodology of Bertsimas and Sim [Op. Res. 2004, 52, 35−53] was applied, which deals with uncertainty in a tractable manner and does not add complexity to the deterministic problem. An industrial-scale study illustrated the benefits of the integrated planning and demonstrated that the modeling of uncertainty in process parameters provides a more practical perspective of the refining industry. In addition, probability bounds of constraint violation were calculated to help decision makers select appropriate parameters to control solution robustness and evaluate trade-offs between conservatism and total profit. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100919z

A systematic computer-aided product design and development procedure / Navid Omidbakhsh in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14925-14934 Titre : A systematic computer-aided product design and development procedure : Case of disinfectant formulations Type de document : texte imprimé Auteurs : Navid Omidbakhsh, Auteur ; Thomas A. Duever, Auteur ; Ali Elkamel, Auteur Année de publication : 2013 Article en page(s) : pp. 14925-14934 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Product  development  Computer  aid Résumé : Product formulation design involves selecting a few ingredients from a large set through screening based on several criteria, and using the optimal proportion in the formulation. The limitation in the traditional strategy for chemical product formulation design is to carry out a large number of trials, which in most practical cases, is either economically infeasible or a very slow process. Furthermore, the presence of constraints, sometimes contradictory to some extent, further complicates the formulation design process. Such traditional trial-and-error and one-factor-at-a-time methodologies can be very cumbersome. They can also lead to a slow and high-cost process. The outcome of following such techniques does not usually lead to optimal designs. In this work, a methodology that deals with the complexity of product formulation design problem with contradictory constraints is presented and illustrated in a real case study. This methodology starts with defining needs for a new product and generating ideas. It then screens the candidate ingredients, using design of experiment techniques, and develops a model for each response. It then inverts the models using a nonlinear optimization technique, and obtains an optimal design for the product based on the desired properties. This methodology is proven to be more effective, faster, and less expensive in the development of new products or improvements on the existing ones. Furthermore, the final product is an optimal formulation, with respect to a preset performance measure and desired properties. The procedure is illustrated and tested on the case of disinfectant formulations. The optimized formulation was prepared, tested, and compared to an existing formulation. The optimized formulation faired significantly better than the existing product, in terms of technical and economic preference. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620405 [article] A systematic computer-aided product design and development procedure : Case of disinfectant formulations [texte imprimé] / Navid Omidbakhsh, Auteur ; Thomas A. Duever, Auteur ; Ali Elkamel, Auteur . - 2013 . - pp. 14925-14934. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14925-14934 Mots-clés : Product  development  Computer  aid Résumé : Product formulation design involves selecting a few ingredients from a large set through screening based on several criteria, and using the optimal proportion in the formulation. The limitation in the traditional strategy for chemical product formulation design is to carry out a large number of trials, which in most practical cases, is either economically infeasible or a very slow process. Furthermore, the presence of constraints, sometimes contradictory to some extent, further complicates the formulation design process. Such traditional trial-and-error and one-factor-at-a-time methodologies can be very cumbersome. They can also lead to a slow and high-cost process. The outcome of following such techniques does not usually lead to optimal designs. In this work, a methodology that deals with the complexity of product formulation design problem with contradictory constraints is presented and illustrated in a real case study. This methodology starts with defining needs for a new product and generating ideas. It then screens the candidate ingredients, using design of experiment techniques, and develops a model for each response. It then inverts the models using a nonlinear optimization technique, and obtains an optimal design for the product based on the desired properties. This methodology is proven to be more effective, faster, and less expensive in the development of new products or improvements on the existing ones. Furthermore, the final product is an optimal formulation, with respect to a preset performance measure and desired properties. The procedure is illustrated and tested on the case of disinfectant formulations. The optimized formulation was prepared, tested, and compared to an existing formulation. The optimized formulation faired significantly better than the existing product, in terms of technical and economic preference. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620405

Systematic statistical-based approach for product design / Navid Omidbakhsh in Industrial & engineering chemistry research, Vol. 49 N° 1 (Janvier 2010) 

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