Documents disponibles écrits par cet auteur

Analysis of optimal control problems and plant debottlenecking for urea granulation circuits / Ivana M. Cotabarren in Industrial & engineering chemistry research, Vol. 50 N° 21 (Novembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11996-12010 Titre : Analysis of optimal control problems and plant debottlenecking for urea granulation circuits Type de document : texte imprimé Auteurs : Ivana M. Cotabarren, Auteur ; Diego Bertín, Auteur ; Juliana Pina, Auteur Année de publication : 2011 Article en page(s) : pp. 11996-12010 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Granulation  Optimal  control Résumé : The optimal control of a complete urea granulation circuit is studied in this work. The dynamic circuit operation is modeled by means of population, mass, and energy balances for the equipment of an industrial urea granulation flowsheet. The objective for the optimal control of the granulation circuit is to drive the process from a given steady-state (corresponding to the nominal capacity of a large-scale plant) to another one, by maximizing the throughput during the transient To this aim, realistic operating constraints are taken into account and, based on an analysis of the active physical limitations, different optimal control variables are selected (i.e., urea melt flow rate, granulator discharge area, and granulator fluidization air temperature and mass flow rate). The results provide new promising operating points, which can be achieved by tracking the calculated optimal time-trajectories for the selected control variables, and give insights into the main plant bottlenecks. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697520 [article] Analysis of optimal control problems and plant debottlenecking for urea granulation circuits [texte imprimé] / Ivana M. Cotabarren, Auteur ; Diego Bertín, Auteur ; Juliana Pina, Auteur . - 2011 . - pp. 11996-12010. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11996-12010 Mots-clés : Granulation  Optimal  control Résumé : The optimal control of a complete urea granulation circuit is studied in this work. The dynamic circuit operation is modeled by means of population, mass, and energy balances for the equipment of an industrial urea granulation flowsheet. The objective for the optimal control of the granulation circuit is to drive the process from a given steady-state (corresponding to the nominal capacity of a large-scale plant) to another one, by maximizing the throughput during the transient To this aim, realistic operating constraints are taken into account and, based on an analysis of the active physical limitations, different optimal control variables are selected (i.e., urea melt flow rate, granulator discharge area, and granulator fluidization air temperature and mass flow rate). The results provide new promising operating points, which can be achieved by tracking the calculated optimal time-trajectories for the selected control variables, and give insights into the main plant bottlenecks. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697520

Dynamics of an industrial fluidized-Bed granulator for urea production / Diego E. Bertín in Industrial & engineering chemistry research, Vol. 49 N° 1 (Janvier 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 317–326 Titre : Dynamics of an industrial fluidized-Bed granulator for urea production Type de document : texte imprimé Auteurs : Diego E. Bertín, Auteur ; Juliana Pina, Auteur ; Verónica Bucalá, Auteur Année de publication : 2010 Article en page(s) : pp. 317–326 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Dynamics--Industrial--Fluidized-Bed--Granulator--Urea  Production Résumé : Granulation is one of the fundamental operations in particulate processing; however, there is still need to provide insight into the complex dynamic state behavior of these units. The unsteady state of an industrial multichamber fluidized-bed granulator for urea production, with variable mass holdup, is studied under different imposed step changes in key operating variables. For the assayed disturbances, the unit dynamics is considerably slow. In fact, many important state variables (e.g., bed height, pressure drop, solid mass flow, etc.) required more than 1 h to achieve the new steady state. The observed nonsteady behavior indicates the need of an efficient control to return the system rapidly to the desired operational point. The discharge area, fluidization air flow rate, and temperature were determined to be the more appropriate manipulative variables, for granulator stability control purposes. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901155a [article] Dynamics of an industrial fluidized-Bed granulator for urea production [texte imprimé] / Diego E. Bertín, Auteur ; Juliana Pina, Auteur ; Verónica Bucalá, Auteur . - 2010 . - pp. 317–326. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 1 (Janvier 2010) . - pp. 317–326 Mots-clés : Dynamics--Industrial--Fluidized-Bed--Granulator--Urea  Production Résumé : Granulation is one of the fundamental operations in particulate processing; however, there is still need to provide insight into the complex dynamic state behavior of these units. The unsteady state of an industrial multichamber fluidized-bed granulator for urea production, with variable mass holdup, is studied under different imposed step changes in key operating variables. For the assayed disturbances, the unit dynamics is considerably slow. In fact, many important state variables (e.g., bed height, pressure drop, solid mass flow, etc.) required more than 1 h to achieve the new steady state. The observed nonsteady behavior indicates the need of an efficient control to return the system rapidly to the desired operational point. The discharge area, fluidization air flow rate, and temperature were determined to be the more appropriate manipulative variables, for granulator stability control purposes. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901155a

Solids transport modeling in a fluidized drum granulator / Rodrigo Rojas in Industrial & engineering chemistry research, Vol. 49 N° 15 (Août 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 15 (Août 2010) . - pp 6986–6997 Titre : Solids transport modeling in a fluidized drum granulator Type de document : texte imprimé Auteurs : Rodrigo Rojas, Auteur ; Juliana Pina, Auteur ; Verónica Bucalá, Auteur Année de publication : 2010 Article en page(s) : pp 6986–6997 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Solids  transport  Granulator. Résumé : The fluidized-bed granulator (FDG) involves the use of a fluidized bed in a drum granulator, which is a horizontal cylinder fitted with internal flights. Despite its demonstrated success on an industrial scale, there are few published fundamental studies of this granulation process. In this work, a mathematical model to represent the solids flow pattern within the different active and passive zones of the rotating FDGs is developed. The fluidization table geometry as well as the angular velocity, drum inclination angle, and flights number strongly affect the mass holdups. Relatively high rotational speeds, inclination angles, and number of flights allow increasing the active mass holdups, reducing the passive mass, and eliminating the kilning flow. The model presented in this work, which accounts for the solids mass flows and holdups in the different zones of a FDG, provides a firm foundation for integration with energy and population balances. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901691v [article] Solids transport modeling in a fluidized drum granulator [texte imprimé] / Rodrigo Rojas, Auteur ; Juliana Pina, Auteur ; Verónica Bucalá, Auteur . - 2010 . - pp 6986–6997. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 15 (Août 2010) . - pp 6986–6997 Mots-clés : Solids  transport  Granulator. Résumé : The fluidized-bed granulator (FDG) involves the use of a fluidized bed in a drum granulator, which is a horizontal cylinder fitted with internal flights. Despite its demonstrated success on an industrial scale, there are few published fundamental studies of this granulation process. In this work, a mathematical model to represent the solids flow pattern within the different active and passive zones of the rotating FDGs is developed. The fluidization table geometry as well as the angular velocity, drum inclination angle, and flights number strongly affect the mass holdups. Relatively high rotational speeds, inclination angles, and number of flights allow increasing the active mass holdups, reducing the passive mass, and eliminating the kilning flow. The model presented in this work, which accounts for the solids mass flows and holdups in the different zones of a FDG, provides a firm foundation for integration with energy and population balances. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901691v