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Characterization and dynamic optimization of membrane-assisted crystallization of adipic acid / Jelan Kuhn in Industrial & engineering chemistry research, Vol. 48 N° 11 (Juin 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 11 (Juin 2009) . - pp. 5360–5369 Titre : Characterization and dynamic optimization of membrane-assisted crystallization of adipic acid Type de document : texte imprimé Auteurs : Jelan Kuhn, Auteur ; Richard Lakerveld, Auteur ; Herman J. M. Kramer, Auteur Année de publication : 2009 Article en page(s) : pp. 5360–5369 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Membrane-assisted  crystallization  Reverse  osmosis  (MaC-RO)  Aqueous  adipic  acid  solution Résumé : The concept of membrane-assisted crystallization using reverse osmosis (MaC-RO) shows a high potential in decreasing energy conversion as compared to evaporative crystallization. A setup has been constructed for MaC-RO, using two separate loops for membrane separation and crystallization. In this study we focus on the characterization of the membrane performance in solvent removal from an aqueous adipic acid solution under reverse osmosis conditions. A semiempirical model was developed for the flux as a function of temperature, concentration, and pressure difference across the membrane. The presence of adipic acid strongly reduces the flux at the same feed temperature and pressure, as compared to the flux from a pure water feed. This effect could be attributed to competitive adsorption on the membrane surface and, to a lesser extent, concentration polarization. For a batch MaC-RO process a dynamic optimization was conducted by changing the operational policy (membrane feed pressure, flow rate, and temperature). The energy conversion is minimized while maintaining a high, prior optimized product yield, defined as the volume-based mean size. The so-determined optimal operational policy results in a six times lower energy conversion as compared to evaporative crystallization with a final mean size that closely corresponds to the maximum mean size that can be achieved in a crystallizer with ideal control of supersaturation. This study demonstrates the potential of the concept of MaC-RO in terms of control over product quality and reduction of energy conversion. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie802010z [article] Characterization and dynamic optimization of membrane-assisted crystallization of adipic acid [texte imprimé] / Jelan Kuhn, Auteur ; Richard Lakerveld, Auteur ; Herman J. M. Kramer, Auteur . - 2009 . - pp. 5360–5369. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 11 (Juin 2009) . - pp. 5360–5369 Mots-clés : Membrane-assisted  crystallization  Reverse  osmosis  (MaC-RO)  Aqueous  adipic  acid  solution Résumé : The concept of membrane-assisted crystallization using reverse osmosis (MaC-RO) shows a high potential in decreasing energy conversion as compared to evaporative crystallization. A setup has been constructed for MaC-RO, using two separate loops for membrane separation and crystallization. In this study we focus on the characterization of the membrane performance in solvent removal from an aqueous adipic acid solution under reverse osmosis conditions. A semiempirical model was developed for the flux as a function of temperature, concentration, and pressure difference across the membrane. The presence of adipic acid strongly reduces the flux at the same feed temperature and pressure, as compared to the flux from a pure water feed. This effect could be attributed to competitive adsorption on the membrane surface and, to a lesser extent, concentration polarization. For a batch MaC-RO process a dynamic optimization was conducted by changing the operational policy (membrane feed pressure, flow rate, and temperature). The energy conversion is minimized while maintaining a high, prior optimized product yield, defined as the volume-based mean size. The so-determined optimal operational policy results in a six times lower energy conversion as compared to evaporative crystallization with a final mean size that closely corresponds to the maximum mean size that can be achieved in a crystallizer with ideal control of supersaturation. This study demonstrates the potential of the concept of MaC-RO in terms of control over product quality and reduction of energy conversion. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie802010z

Minimization of attrition and breakage in an airlift crystallizer / Anamaria Soare in Industrial & engineering chemistry research, Vol. 51 N° 33 (Août 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 33 (Août 2012) . - pp. 10895-10909 Titre : Minimization of attrition and breakage in an airlift crystallizer Type de document : texte imprimé Auteurs : Anamaria Soare, Auteur ; Richard Lakerveld, Auteur ; Jurjen van Royen, Auteur Année de publication : 2012 Article en page(s) : pp. 10895-10909 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Crystallizer  Attrition Résumé : Minimization of secondary nucleation by attrition in industrial crystallizers is a major challenge. In this work, a novel airlift crystallizer has been designed, constructed, and experimentally tested aiming at the reduction of attrition by using air for mixing instead of a stirrer or a circulation pump. It is experimentally demonstrated that in this crystallizer ideal growth, i.e., growth of crystals without any nucleation, can be approached up to a seeding load of 0.5% and crystal size of up to 600 μm. Attrition is considerably decreased in an airlift crystallizer compared to conventional impeller-mixed crystallizers. This air-mixed crystallizer enables the production of crystals of high quality and offers a large flexibility of the final crystal size by manipulating the air flow rate and the sparger design. Comparison of different designs showed a large effect of a gas disengagement zone on the performance of the crystallizer, especially when large crystals were desired. The disengagement zone allows high circulation velocities and thus good mixing without entrainment of the gas bubbles in the downcomer, approaching a uniform suspension of the crystals. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26286464 [article] Minimization of attrition and breakage in an airlift crystallizer [texte imprimé] / Anamaria Soare, Auteur ; Richard Lakerveld, Auteur ; Jurjen van Royen, Auteur . - 2012 . - pp. 10895-10909. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 33 (Août 2012) . - pp. 10895-10909 Mots-clés : Crystallizer  Attrition Résumé : Minimization of secondary nucleation by attrition in industrial crystallizers is a major challenge. In this work, a novel airlift crystallizer has been designed, constructed, and experimentally tested aiming at the reduction of attrition by using air for mixing instead of a stirrer or a circulation pump. It is experimentally demonstrated that in this crystallizer ideal growth, i.e., growth of crystals without any nucleation, can be approached up to a seeding load of 0.5% and crystal size of up to 600 μm. Attrition is considerably decreased in an airlift crystallizer compared to conventional impeller-mixed crystallizers. This air-mixed crystallizer enables the production of crystals of high quality and offers a large flexibility of the final crystal size by manipulating the air flow rate and the sparger design. Comparison of different designs showed a large effect of a gas disengagement zone on the performance of the crystallizer, especially when large crystals were desired. The disengagement zone allows high circulation velocities and thus good mixing without entrainment of the gas bubbles in the downcomer, approaching a uniform suspension of the crystals. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26286464

A plant-wide dynamic model of a continuous pharmaceutical process / Brahim Benyahia in Industrial & engineering chemistry research, Vol. 51 N° 47 (Novembre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 47 (Novembre 2012) . - pp 15393–15412 Titre : A plant-wide dynamic model of a continuous pharmaceutical process Type de document : texte imprimé Auteurs : Brahim Benyahia, Auteur ; Richard Lakerveld, Auteur ; Paul I. Barton, Auteur Année de publication : 2013 Article en page(s) : pp 15393–15412 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Pharmaceutical  industry Résumé : The pharmaceutical industry has historically benefited from high profit margins for their products, and over the years limited efforts have been made to change the main manufacturing concept from batch into continuous. However, over the past decade, as a result of an increased demand for more efficient and cost-effective processes, interest has grown in the application of continuous manufacturing to address economical and technical issues in the pharmaceutical field. This option is becoming more viable, particularly with the implementation of new process analytical technology (PAT). In this paper, we present a plant-wide mathematical model inspired by a recently developed continuous pharmaceutical pilot plant. This model is first used to simulate a base case that shows typical limitations in achieving simultaneously high productivity and quality. The main critical quality attribute considered is the purity of the final product. To alleviate the base case limitations and improve the pilot plant performance, the effects of several design parameters are investigated and the most critical are identified. In addition, alternative start-up scenarios are considered to improve the transient performance of the pilot plant, particularly time to steady state. The environmental footprint of the pilot plant is evaluated and shown to be low. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3006319 [article] A plant-wide dynamic model of a continuous pharmaceutical process [texte imprimé] / Brahim Benyahia, Auteur ; Richard Lakerveld, Auteur ; Paul I. Barton, Auteur . - 2013 . - pp 15393–15412. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 47 (Novembre 2012) . - pp 15393–15412 Mots-clés : Pharmaceutical  industry Résumé : The pharmaceutical industry has historically benefited from high profit margins for their products, and over the years limited efforts have been made to change the main manufacturing concept from batch into continuous. However, over the past decade, as a result of an increased demand for more efficient and cost-effective processes, interest has grown in the application of continuous manufacturing to address economical and technical issues in the pharmaceutical field. This option is becoming more viable, particularly with the implementation of new process analytical technology (PAT). In this paper, we present a plant-wide mathematical model inspired by a recently developed continuous pharmaceutical pilot plant. This model is first used to simulate a base case that shows typical limitations in achieving simultaneously high productivity and quality. The main critical quality attribute considered is the purity of the final product. To alleviate the base case limitations and improve the pilot plant performance, the effects of several design parameters are investigated and the most critical are identified. In addition, alternative start-up scenarios are considered to improve the transient performance of the pilot plant, particularly time to steady state. The environmental footprint of the pilot plant is evaluated and shown to be low. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3006319