Documents disponibles écrits par cet auteur

Conceptual synthesis of gasification-based biorefineries using thermodynamic equilibrium optimization models / Douglas H. S. Tay in Industrial & engineering chemistry research, Vol. 50 N° 18 (Septembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 18 (Septembre 2011) . - pp. 10681–10695 Titre : Conceptual synthesis of gasification-based biorefineries using thermodynamic equilibrium optimization models Type de document : texte imprimé Auteurs : Douglas H. S. Tay, Auteur ; Houssein Kheireddine, Auteur ; Denny K. S. Ng, Auteur Année de publication : 2011 Article en page(s) : pp. 10681–10695 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Modeling  Optimization  Thermodynamic  equilibrium  Gasification Résumé : An integrated biorefinery is a processing facility that converts biomass into a wide range of biochemical products and also provides a sustainable supply of biofuels and energy. One of its critical features is the ability to handle a wide variety of biomass feedstocks and the capacity to produce a portfolio of products through multiple conversion technologies. The gasification process is recognized as a promising option for initial processing of biomass, as it is a robust thermal conversion process. The composition of syngas, especially the ratio ofH2to CO, is crucial when the syngas is further converted to liquid fuels and chemicals. To optimize the production of syngas for application in an integrated biorefinery, a systematic approach is needed to design the system and predict its performance. In this work, a modular optimization approach to link a stoichiometric equilibrium model of biomass gasification and structural models of synthesis processes is developed. In this approach, all model components are solved simultaneously. The approach is used to evaluate the equilibrium composition of syngas, the optimum operating temperature, and the required types and amounts of oxidants. Two case studies are used to illustrate the approach. A sensitivity analysis is then performed to assess the most significant factors affecting the process economics in these examples. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24523886 [article] Conceptual synthesis of gasification-based biorefineries using thermodynamic equilibrium optimization models [texte imprimé] / Douglas H. S. Tay, Auteur ; Houssein Kheireddine, Auteur ; Denny K. S. Ng, Auteur . - 2011 . - pp. 10681–10695. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 18 (Septembre 2011) . - pp. 10681–10695 Mots-clés : Modeling  Optimization  Thermodynamic  equilibrium  Gasification Résumé : An integrated biorefinery is a processing facility that converts biomass into a wide range of biochemical products and also provides a sustainable supply of biofuels and energy. One of its critical features is the ability to handle a wide variety of biomass feedstocks and the capacity to produce a portfolio of products through multiple conversion technologies. The gasification process is recognized as a promising option for initial processing of biomass, as it is a robust thermal conversion process. The composition of syngas, especially the ratio ofH2to CO, is crucial when the syngas is further converted to liquid fuels and chemicals. To optimize the production of syngas for application in an integrated biorefinery, a systematic approach is needed to design the system and predict its performance. In this work, a modular optimization approach to link a stoichiometric equilibrium model of biomass gasification and structural models of synthesis processes is developed. In this approach, all model components are solved simultaneously. The approach is used to evaluate the equilibrium composition of syngas, the optimum operating temperature, and the required types and amounts of oxidants. Two case studies are used to illustrate the approach. A sensitivity analysis is then performed to assess the most significant factors affecting the process economics in these examples. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24523886

Optimization of direct recycle networks with the simultaneous consideration of property, mass, and thermal effects / Houssein Kheireddine in Industrial & engineering chemistry research, Vol. 50 N° 7 (Avril 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 7 (Avril 2011) . - pp. 3754–3762 Titre : Optimization of direct recycle networks with the simultaneous consideration of property, mass, and thermal effects Type de document : texte imprimé Auteurs : Houssein Kheireddine, Auteur ; Younas Dadmohammadi, Auteur Année de publication : 2011 Article en page(s) : pp. 3754–3762 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Optimization  Recycle  networks Résumé : There is a growing need to develop systematic and cost-effective design strategies for direct recycle strategies that lead to the reduction in the consumption of fresh materials and in the discharge of waste streams. Traditionally, most of the previous research efforts in the area of designing direct-recycle networks have considered the chemical composition as the basis for process constraints. However, there are many design problems that are not component-based; instead, they are property-based (e.g., pH, density, viscosity, chemical oxygen demand (COD), basic oxygen demand (BOD), toxicity). Additionally, thermal constraints (e.g., stream temperature) may be required to identify acceptable recycles. In this work, we introduce a novel approach to the design of recycle networks that allows the simultaneous consideration of mass, thermal, and property constraints. Furthermore, the devised approach also accounts for the heat of mixing and for the interdependence of properties. An optimization formulation is developed to embed all potential configurations of interest and to model the mass, thermal, and property characteristics of the targeted streams and units. Solution strategies are developed to identify stream allocation and targets for minimum fresh usage and waste discharge. A case study is solved to illustrate the concept of the proposed approach and its computational aspects. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1012272 [article] Optimization of direct recycle networks with the simultaneous consideration of property, mass, and thermal effects [texte imprimé] / Houssein Kheireddine, Auteur ; Younas Dadmohammadi, Auteur . - 2011 . - pp. 3754–3762. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 7 (Avril 2011) . - pp. 3754–3762 Mots-clés : Optimization  Recycle  networks Résumé : There is a growing need to develop systematic and cost-effective design strategies for direct recycle strategies that lead to the reduction in the consumption of fresh materials and in the discharge of waste streams. Traditionally, most of the previous research efforts in the area of designing direct-recycle networks have considered the chemical composition as the basis for process constraints. However, there are many design problems that are not component-based; instead, they are property-based (e.g., pH, density, viscosity, chemical oxygen demand (COD), basic oxygen demand (BOD), toxicity). Additionally, thermal constraints (e.g., stream temperature) may be required to identify acceptable recycles. In this work, we introduce a novel approach to the design of recycle networks that allows the simultaneous consideration of mass, thermal, and property constraints. Furthermore, the devised approach also accounts for the heat of mixing and for the interdependence of properties. An optimization formulation is developed to embed all potential configurations of interest and to model the mass, thermal, and property characteristics of the targeted streams and units. Solution strategies are developed to identify stream allocation and targets for minimum fresh usage and waste discharge. A case study is solved to illustrate the concept of the proposed approach and its computational aspects. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1012272