Modelling geometrical and fluid-dynamic aspects of a continuous fluidized bed crystallizer for separation of enantiomers

- A process for continuous separation of enantiomers is presented.
- A mathematical population balance model of the process is suggested.
- Simulations identify key parameters for optimizing product mass and crystal size.

Continuous selective crystallization using mixed suspension mixed product removal (MSMPR) crystallizers is an attractive method for separating enantiomers. Recent experimental results confirm the feasibility of the approach, but also indicate that the operation conditions for nominal operation lie in a rather small window. A systematic analysis and an optimal design are needed to exploit the full potential of the method. In this contribution, a mathematical process model based on population balance equations is presented. In contrast to other studies in literature, the considered crystallizer is not a stirred tank, but has a conical shape that requires a spatially distributed model formulation. Parameter studies identify the key operation and design parameters for maximizing the mass of the product crystals and for shaping their size distribution. The proposed model focuses on geometrical and fluid-dynamic aspects, but at the current stage does not include purity aspects.