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Combined quadrature method of moments and method of characteristics approach for efficient solution of population balance models for dynamic modeling and crystal size distribution control of crystallization processes / E. Aamir in Industrial & engineering chemistry research, Vol. 48 N° 18 (Septembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 18 (Septembre 2009) . - pp. 8575–8584 Titre : Combined quadrature method of moments and method of characteristics approach for efficient solution of population balance models for dynamic modeling and crystal size distribution control of crystallization processes Type de document : texte imprimé Auteurs : E. Aamir, Auteur ; Z. K. Nagy, Auteur ; C. D. Rielly, Auteur Année de publication : 2010 Article en page(s) : pp. 8575–8584 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Crystal  size  distribution  Quadrature  method  of  moments  Method  of  characteristics  Crystallization  processes Résumé : The paper presents a novel methodology for the estimation of the shape of the crystal size distribution (CSD) during a crystallization process. The approach, based on a combination of the quadrature method of moments (QMOM) and the method of characteristics (MOCH), provides a computationally efficient solution of the population balance equation (PBE) and hence a fast prediction of the dynamic evolution of the CSD for an entire batch. Furthermore, under the assumption that for supersaturation-controlled crystallization the main phenomenon is growth, an analytical CSD estimator is derived for generic size-dependent growth kinetics. These approaches are evaluated for the crystallization of potassium alum in water. The model parameters are identified on the basis of industrial experimental data, obtained using an efficient implementation of supersaturation control. The proposed methods are able to predict and reconstruct the dynamic evolution of the CSD during the batch. The QMOM−MOCH solution approach is evaluated in a model-based dynamic optimization study, which aims to obtain the optimal temperature profiles required to achieve desired target CSDs. The technique can serve as a soft sensor for predicting the CSD, or as a computationally efficient algorithm for off-line design or online adaptation of operating policies based on knowledge of the full CSD data. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900430t [article] Combined quadrature method of moments and method of characteristics approach for efficient solution of population balance models for dynamic modeling and crystal size distribution control of crystallization processes [texte imprimé] / E. Aamir, Auteur ; Z. K. Nagy, Auteur ; C. D. Rielly, Auteur . - 2010 . - pp. 8575–8584. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 18 (Septembre 2009) . - pp. 8575–8584 Mots-clés : Crystal  size  distribution  Quadrature  method  of  moments  Method  of  characteristics  Crystallization  processes Résumé : The paper presents a novel methodology for the estimation of the shape of the crystal size distribution (CSD) during a crystallization process. The approach, based on a combination of the quadrature method of moments (QMOM) and the method of characteristics (MOCH), provides a computationally efficient solution of the population balance equation (PBE) and hence a fast prediction of the dynamic evolution of the CSD for an entire batch. Furthermore, under the assumption that for supersaturation-controlled crystallization the main phenomenon is growth, an analytical CSD estimator is derived for generic size-dependent growth kinetics. These approaches are evaluated for the crystallization of potassium alum in water. The model parameters are identified on the basis of industrial experimental data, obtained using an efficient implementation of supersaturation control. The proposed methods are able to predict and reconstruct the dynamic evolution of the CSD during the batch. The QMOM−MOCH solution approach is evaluated in a model-based dynamic optimization study, which aims to obtain the optimal temperature profiles required to achieve desired target CSDs. The technique can serve as a soft sensor for predicting the CSD, or as a computationally efficient algorithm for off-line design or online adaptation of operating policies based on knowledge of the full CSD data. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900430t

Experimental evaluation of the targeted direct design of temperature trajectories for growth-dominated crystallization processes using an analytical crystal size distribution estimator / E. Aamir in Industrial & engineering chemistry research, Vol. 51 N° 51 (Décembre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 51 (Décembre 2012) . - pp. 16677–16687 Titre : Experimental evaluation of the targeted direct design of temperature trajectories for growth-dominated crystallization processes using an analytical crystal size distribution estimator Type de document : texte imprimé Auteurs : E. Aamir, Auteur ; C. D. Rielly, Auteur ; Z. K. Nagy, Auteur Année de publication : 2012 Article en page(s) : pp. 16677–16687 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Crystallization  processes Résumé : The paper presents an experimental validation of a novel methodology for the systematic design of the set point operating curves for supersaturation-controlled, seeded crystallization processes, which produces a desired target crystal size distribution (CSD). The direct design approach is based on the idea of operating the system within the metastable zone (MSZ) bounded by the nucleation and the solubility curves. The proposed approach is based on an analytical CSD estimator, obtained by the analytical solution of the population balance equation for supersaturation-controlled growth-dominated processes. Based on the analytical estimator a design parameter for supersaturation-controlled processes is defined as a function of the supersaturation, time, and growth kinetics. Using the design parameter and the analytical CSD estimator, the temperature profiles in the time domain are determined to obtain a target distribution with a desired shape, while maintaining the constant supersaturation. The resulting temperature profile in the time domain can then be used as a set point for the temperature controller. This methodology provides a systematic targeted direct design approach for practical applications and scale-up. Experimental evaluations of two temperature trajectories designed with the proposed approach were carried out to achieve the desired target shape of the CSD. The experiments illustrate that the proposed targeted direct design approach can be used to systematically design different temperature trajectories and hence batch times, which lead to similar desired product CSD. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301610z [article] Experimental evaluation of the targeted direct design of temperature trajectories for growth-dominated crystallization processes using an analytical crystal size distribution estimator [texte imprimé] / E. Aamir, Auteur ; C. D. Rielly, Auteur ; Z. K. Nagy, Auteur . - 2012 . - pp. 16677–16687. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 51 (Décembre 2012) . - pp. 16677–16687 Mots-clés : Crystallization  processes Résumé : The paper presents an experimental validation of a novel methodology for the systematic design of the set point operating curves for supersaturation-controlled, seeded crystallization processes, which produces a desired target crystal size distribution (CSD). The direct design approach is based on the idea of operating the system within the metastable zone (MSZ) bounded by the nucleation and the solubility curves. The proposed approach is based on an analytical CSD estimator, obtained by the analytical solution of the population balance equation for supersaturation-controlled growth-dominated processes. Based on the analytical estimator a design parameter for supersaturation-controlled processes is defined as a function of the supersaturation, time, and growth kinetics. Using the design parameter and the analytical CSD estimator, the temperature profiles in the time domain are determined to obtain a target distribution with a desired shape, while maintaining the constant supersaturation. The resulting temperature profile in the time domain can then be used as a set point for the temperature controller. This methodology provides a systematic targeted direct design approach for practical applications and scale-up. Experimental evaluations of two temperature trajectories designed with the proposed approach were carried out to achieve the desired target shape of the CSD. The experiments illustrate that the proposed targeted direct design approach can be used to systematically design different temperature trajectories and hence batch times, which lead to similar desired product CSD. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301610z