Shortcut model to evaluate the performance of continuous preferential crystallization for conglomerates forming chiral systems

Abstract

The separation of two enantiomers of a chiral molecule is one of the most difficult tasks for separation technology. Among the available methods, Preferential Crystallization (PC) offers a relatively simple and efficient possibility to separate pairs of enantiomers of conglomerate forming chiral systems. To estimate the potential and to design PC processes, mathematical process models are required. Recently, a short-cut model (SCM) was developed which was found capable to predict the course of batch-wise operated PC until nucleation of the unseeded counter-enantiomer terminates the exploitable production period. In this paper the SCM is reformulated in a dimensionless way and extended to describe also more productive continuous operation of PC. Characteristic dimensionless numbers are demonstrated to be instructive to evaluate effects of system specific kinetic parameters and to identify suitable operating conditions. The sensitivity of the continuous PC process with respect to the most relevant model parameters is investigated based on simulation results. Finally, the role of the SCM in the workflow of designing continuous PC processes is summarized.