Preferential Crystallization of l-Asparagine in Water

Because of its simplicity and cost-effectiveness, preferential crystallization (PC) can be considered as one of the most attractive techniques available for enantioseparation. In this paper,the enantioseparation of the nonessential amino acid dl-asparagine (dl-Asn), which belongs to the group of conglomerate forming systems, is studied experimentally and theoretically. Goals of this work are to investigate the applicability of PC of l-Asn·H2O from an aqueous solution of racemic dl-Asn using simple isothermal batch preferential crystallization (SIB-PC) and to provide a reliable database for model validation based on essential model parameters identified. To further improve the performance of PC, two crystallizers can be connected in order to exchange continuously the mother liquors (CIB-PC, coupled isothermal batch preferential crystallization). This new configuration is tested and assessed.