Documents disponibles écrits par cet auteur

Bottom-up modeling of the steam consumption in multipurpose chemical batch plants focusing on identification of the optimization potential / Andrej Szijjarto 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. 7323–7334 Titre : Bottom-up modeling of the steam consumption in multipurpose chemical batch plants focusing on identification of the optimization potential Type de document : texte imprimé Auteurs : Andrej Szijjarto, Auteur ; Stavros Papadokonstantakis, Auteur ; Ulrich Fischer, Auteur Année de publication : 2008 Article en page(s) : p. 7323–7334 Note générale : Chemical engneering Langues : Anglais (eng) Mots-clés : Steam  consumption  Multipurpose  chemical  batch  plant Résumé : A detailed approach for modeling the steam consumption in a multipurpose chemical batch plant was developed, tested, and used for analysis of the energy-efficiency. The main advantage of the approach presented in this paper compared to available modeling approaches is the ability to describe the transient steam consumption. Thus, the new approach can be used for the dynamic optimization of batch operations with respect to the energy efficiency. The bottom-up method was implemented by modeling particular unit operations (UOs) in a case study plant, and validation was accomplished with direct measurements on both UO and building level. The principle of the bottom-up model is a detailed energy balance of each particular UO for which process parameter measurements are necessary as input data. These were extracted from the measurements archive of the case study plant for a period of two months. Process data from almost 1000 sensors installed in ca. 100 UOs were acquired, transformed into a time-series with common time basis, and used as an input data for the model. Special attention was paid to model the losses of the UOs because in earlier studies it was found that these are significant. Loss models were developed in the form of empirical parametric equations considering the losses due to radiation and the internal losses in the heating/cooling system due to inefficient operation. The parameters of the loss models were fitted, based on the developed methodology, to steam measurements of 4 UOs and consequently integrated into the overall bottom-up model for modeling other UOs as well. The energy usage efficiency of the UOs was inferred and the optimization spots were identified. The results in the case study plant have indicated that the energy savings potential for particular UOs with low steam-usage efficiency can be easily identified and serve as a good hint for the overall plant energy auditing and steam consumption optimization. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071291o [article] Bottom-up modeling of the steam consumption in multipurpose chemical batch plants focusing on identification of the optimization potential [texte imprimé] / Andrej Szijjarto, Auteur ; Stavros Papadokonstantakis, Auteur ; Ulrich Fischer, Auteur . - 2008 . - p. 7323–7334. Chemical engneering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N°19 (Octobre 2008) . - p. 7323–7334 Mots-clés : Steam  consumption  Multipurpose  chemical  batch  plant Résumé : A detailed approach for modeling the steam consumption in a multipurpose chemical batch plant was developed, tested, and used for analysis of the energy-efficiency. The main advantage of the approach presented in this paper compared to available modeling approaches is the ability to describe the transient steam consumption. Thus, the new approach can be used for the dynamic optimization of batch operations with respect to the energy efficiency. The bottom-up method was implemented by modeling particular unit operations (UOs) in a case study plant, and validation was accomplished with direct measurements on both UO and building level. The principle of the bottom-up model is a detailed energy balance of each particular UO for which process parameter measurements are necessary as input data. These were extracted from the measurements archive of the case study plant for a period of two months. Process data from almost 1000 sensors installed in ca. 100 UOs were acquired, transformed into a time-series with common time basis, and used as an input data for the model. Special attention was paid to model the losses of the UOs because in earlier studies it was found that these are significant. Loss models were developed in the form of empirical parametric equations considering the losses due to radiation and the internal losses in the heating/cooling system due to inefficient operation. The parameters of the loss models were fitted, based on the developed methodology, to steam measurements of 4 UOs and consequently integrated into the overall bottom-up model for modeling other UOs as well. The energy usage efficiency of the UOs was inferred and the optimization spots were identified. The results in the case study plant have indicated that the energy savings potential for particular UOs with low steam-usage efficiency can be easily identified and serve as a good hint for the overall plant energy auditing and steam consumption optimization. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071291o

Estimation and analysis of energy utilities consumption in batch chemical industry through thermal losses modeling / Claude Rérat in Industrial & engineering chemistry research, Vol.51 N° 31 (Août 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol.51 N° 31 (Août 2012) . - pp. 10416-10432 Titre : Estimation and analysis of energy utilities consumption in batch chemical industry through thermal losses modeling Type de document : texte imprimé Auteurs : Claude Rérat, Auteur ; Stavros Papadokonstantakis, Auteur ; Konrad Hungerbuhler, Auteur Année de publication : 2012 Article en page(s) : pp. 10416-10432 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Utilities  Modeling  Chemical  industry  Batchwise Résumé : A systematic approach for the estimation of energy utility consumption in chemical batch plants is presented and validated. This approach is based on bottom-up modeling of energy use and its conversion in usual energy carriers like steam, cooling water and brine, including estimation of thermal losses. The modeling involves a detailed energy balance of each unit operation using dynamic plant data. Thermal losses are determined using an empirical parametric equation for each equipment and utility. The method was applied to one monoproduct and one multiproduct building of a chemical batch plant comprising 20 main equipments (reactor vessels, heat exchangers and dryers) for the production of 5 specialty chemicals and intermediates over a period of 2 months. For fitting the parameters of the empirical thermal losses models it was crucial to determine the real energy consumption for the investigated equipments. In the lack of installed flowmeters it was tested whether this task can be performed through calibration of the valves controlling the utility distribution based on valve opening. A direct and an indirect calibration method were applied both providing satisfactory level of accuracy. Validation of the bottom-up models was performed at different aggregation levels, including equipment specific unit operations, production lines and overall building energy consumption. The results indicated that for all types of energy utility, equipment and unit operation the consumption could be estimated with a relative error between 5% and 35% depending on the aggregation level. These results can motivate plant managers and process engineers to consider model-based estimation and analysis of energy utilities for monitoring and optimization purposes in industrial practice. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26234073 [article] Estimation and analysis of energy utilities consumption in batch chemical industry through thermal losses modeling [texte imprimé] / Claude Rérat, Auteur ; Stavros Papadokonstantakis, Auteur ; Konrad Hungerbuhler, Auteur . - 2012 . - pp. 10416-10432. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol.51 N° 31 (Août 2012) . - pp. 10416-10432 Mots-clés : Utilities  Modeling  Chemical  industry  Batchwise Résumé : A systematic approach for the estimation of energy utility consumption in chemical batch plants is presented and validated. This approach is based on bottom-up modeling of energy use and its conversion in usual energy carriers like steam, cooling water and brine, including estimation of thermal losses. The modeling involves a detailed energy balance of each unit operation using dynamic plant data. Thermal losses are determined using an empirical parametric equation for each equipment and utility. The method was applied to one monoproduct and one multiproduct building of a chemical batch plant comprising 20 main equipments (reactor vessels, heat exchangers and dryers) for the production of 5 specialty chemicals and intermediates over a period of 2 months. For fitting the parameters of the empirical thermal losses models it was crucial to determine the real energy consumption for the investigated equipments. In the lack of installed flowmeters it was tested whether this task can be performed through calibration of the valves controlling the utility distribution based on valve opening. A direct and an indirect calibration method were applied both providing satisfactory level of accuracy. Validation of the bottom-up models was performed at different aggregation levels, including equipment specific unit operations, production lines and overall building energy consumption. The results indicated that for all types of energy utility, equipment and unit operation the consumption could be estimated with a relative error between 5% and 35% depending on the aggregation level. These results can motivate plant managers and process engineers to consider model-based estimation and analysis of energy utilities for monitoring and optimization purposes in industrial practice. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26234073

Model - based identification and analysis of the energy saving potential in batch chemical processes / Andrej Szijjarto in Industrial & engineering chemistry research, Vol. 51 N° 34 (Août 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11170-11182 Titre : Model - based identification and analysis of the energy saving potential in batch chemical processes Type de document : texte imprimé Auteurs : Andrej Szijjarto, Auteur ; Stavros Papadokonstantakis, Auteur ; Konrad Hungerbühler, Auteur Année de publication : 2012 Article en page(s) : pp. 11170-11182 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Batchwise  Energy  conservation  Modeling Résumé : Optimization of energy consumption for reducing the relevant costs and environmental impacts is constantly gaining attention in chemical batch production. Existing methodologies focus on heat integration considering scheduling constraints and typically result in trade-offs between capital investment and operational costs. However, in multipurpose batch plants, even the allocation of energy flows and the consistent operation according to production recipes pose a great challenge due to batch-to-batch variability and lack of energy utility consumption meters. This paper utilizes a bottom-up modeling approach for energy utility consumption and proposes a method for model-based identification of the energy saving potential in chemical batch plants. The bottom-up models can accurately track the energy utility consumption at various production levels and are used as "soft sensors" for energy efficiency analysis studies. In this context, a set of energy key performance indicators (EKPIs) is proposed for quantifying efficiency in energy use, and an energy saving potential index (ESPI) based on historical plant performance serves as a shortcut method in the case of missing or inaccurate production recipes. The methodology is applied to an industrial multipurpose batch plant for specialty chemicals, exemplifying the obtained efficiency results and targeting energy saving potential for steam consumption. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26299443 [article] Model - based identification and analysis of the energy saving potential in batch chemical processes [texte imprimé] / Andrej Szijjarto, Auteur ; Stavros Papadokonstantakis, Auteur ; Konrad Hungerbühler, Auteur . - 2012 . - pp. 11170-11182. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11170-11182 Mots-clés : Batchwise  Energy  conservation  Modeling Résumé : Optimization of energy consumption for reducing the relevant costs and environmental impacts is constantly gaining attention in chemical batch production. Existing methodologies focus on heat integration considering scheduling constraints and typically result in trade-offs between capital investment and operational costs. However, in multipurpose batch plants, even the allocation of energy flows and the consistent operation according to production recipes pose a great challenge due to batch-to-batch variability and lack of energy utility consumption meters. This paper utilizes a bottom-up modeling approach for energy utility consumption and proposes a method for model-based identification of the energy saving potential in chemical batch plants. The bottom-up models can accurately track the energy utility consumption at various production levels and are used as "soft sensors" for energy efficiency analysis studies. In this context, a set of energy key performance indicators (EKPIs) is proposed for quantifying efficiency in energy use, and an energy saving potential index (ESPI) based on historical plant performance serves as a shortcut method in the case of missing or inaccurate production recipes. The methodology is applied to an industrial multipurpose batch plant for specialty chemicals, exemplifying the obtained efficiency results and targeting energy saving potential for steam consumption. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26299443