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Conceptual evaluation of integrated process configurations for the recovery of i-phenylalanine product crystals during fermentation / Cuellar, Maria C. in Industrial & engineering chemistry research, Vol. 49 N° 2 (Janvier 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 2 (Janvier 2010) . - pp 682–689 Titre : Conceptual evaluation of integrated process configurations for the recovery of i-phenylalanine product crystals during fermentation Type de document : texte imprimé Auteurs : Cuellar, Maria C., Auteur ; Straathof, Adrie J. J., Auteur ; Van de Sandt, Emile J. A. X., Auteur Année de publication : 2010 Article en page(s) : pp 682–689 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Amino  acid  Anhydrate  crystals. Résumé : The production of the amino acid l-phenylalanine (Phe) by fermentation is in many cases limited by the tight regulation of the microbial pathway leading to Phe synthesis. One way of circumventing feedback repression is to remove the product from the vicinity of the micro-organism as soon as it is being formed. In the case of Phe, techniques like adsorption and extraction have been applied with this aim. In these processes, however, additional recovery steps are required in order to obtain the product as anhydrate crystals, which is its commercial form. In this work we evaluated conceptually the recovery of Phe anhydrate crystals during a fermentation process. The product recovery consisted of water removal by reverse osmosis, crystallization, and recycle of the mother liquor either to the fermenter, to the water removal unit or to both. By maintaining the Phe mass fraction in the fermenter at about 17 g kg−1 the fermentation productivity increased according to the calculations from 0.66 g kg−1 h−1, without product removal, to 1.07 g kg−1 h−1, with product removal, where about 70% of the produced Phe was directly recovered as anhydrate crystals. By means of a simplified economic model it was shown that the membranes required for cell retention and water removal have much more impact on the economic performance of the process than the consumption of raw materials, and therefore, the favored recycling option for the mother liquor is to the water removal unit DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901007g [article] Conceptual evaluation of integrated process configurations for the recovery of i-phenylalanine product crystals during fermentation [texte imprimé] / Cuellar, Maria C., Auteur ; Straathof, Adrie J. J., Auteur ; Van de Sandt, Emile J. A. X., Auteur . - 2010 . - pp 682–689. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 2 (Janvier 2010) . - pp 682–689 Mots-clés : Amino  acid  Anhydrate  crystals. Résumé : The production of the amino acid l-phenylalanine (Phe) by fermentation is in many cases limited by the tight regulation of the microbial pathway leading to Phe synthesis. One way of circumventing feedback repression is to remove the product from the vicinity of the micro-organism as soon as it is being formed. In the case of Phe, techniques like adsorption and extraction have been applied with this aim. In these processes, however, additional recovery steps are required in order to obtain the product as anhydrate crystals, which is its commercial form. In this work we evaluated conceptually the recovery of Phe anhydrate crystals during a fermentation process. The product recovery consisted of water removal by reverse osmosis, crystallization, and recycle of the mother liquor either to the fermenter, to the water removal unit or to both. By maintaining the Phe mass fraction in the fermenter at about 17 g kg−1 the fermentation productivity increased according to the calculations from 0.66 g kg−1 h−1, without product removal, to 1.07 g kg−1 h−1, with product removal, where about 70% of the produced Phe was directly recovered as anhydrate crystals. By means of a simplified economic model it was shown that the membranes required for cell retention and water removal have much more impact on the economic performance of the process than the consumption of raw materials, and therefore, the favored recycling option for the mother liquor is to the water removal unit DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901007g

Limits of operation for the integration of water removal by membranes and crystallization of l-phenylalanine / Cuellar, Maria C. in Industrial & engineering chemistry research, Vol. 48 N°3 (Février 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N°3 (Février 2009) . - p. 1566–1573 Titre : Limits of operation for the integration of water removal by membranes and crystallization of l-phenylalanine Type de document : texte imprimé Auteurs : Cuellar, Maria C., Auteur ; Simone N. Herreilers, Auteur ; Straathof, Adrie J. J., Auteur Année de publication : 2009 Article en page(s) : p. 1566–1573 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : water  Crystallization  process  Phenylalanine Résumé : Integration of crystallization and water removal using membrane technology is being used as a means to improve control over supersaturation generation and, consequently, to improve crystal quality. However, it is not clear yet how water removal, which has a limited window of operation, can be combined with crystallization in case of occurrence of several crystal forms (and, therefore, also a limited window of operation). In this work we evaluated the use of nanofiltration and reverse osmosis for water removal to achieve selective crystallization of l-phenylalanine anhydrate from aqueous solution. Water removal and crystallization were first studied separately, and models were used to define the limits of operation for the coupled system so that the target crystal form and production rate could be achieved. A narrow window of operation was obtained, and it was shown that practical implementation can be difficult due to operation near the limits of the window of operation. Possibilities for widening the window of operation are briefly discussed. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8012659 [article] Limits of operation for the integration of water removal by membranes and crystallization of l-phenylalanine [texte imprimé] / Cuellar, Maria C., Auteur ; Simone N. Herreilers, Auteur ; Straathof, Adrie J. J., Auteur . - 2009 . - p. 1566–1573. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N°3 (Février 2009) . - p. 1566–1573 Mots-clés : water  Crystallization  process  Phenylalanine Résumé : Integration of crystallization and water removal using membrane technology is being used as a means to improve control over supersaturation generation and, consequently, to improve crystal quality. However, it is not clear yet how water removal, which has a limited window of operation, can be combined with crystallization in case of occurrence of several crystal forms (and, therefore, also a limited window of operation). In this work we evaluated the use of nanofiltration and reverse osmosis for water removal to achieve selective crystallization of l-phenylalanine anhydrate from aqueous solution. Water removal and crystallization were first studied separately, and models were used to define the limits of operation for the coupled system so that the target crystal form and production rate could be achieved. A narrow window of operation was obtained, and it was shown that practical implementation can be difficult due to operation near the limits of the window of operation. Possibilities for widening the window of operation are briefly discussed. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8012659