Shortcut Model for Batch Preferential Crystallization Coupled with Racemization for Conglomerate-Forming Chiral...

Area of Science:

• Chemical Engineering
• Crystallization Science
• Chiral Separations

Background:

• Preferential crystallization (PC) is a method for separating enantiomers in conglomerate systems.
• Current PC methods are limited to a 50% yield, hindering the recovery of valuable counter-enantiomers.
• Shortcut models (SCM) exist but require parameter estimation from limited data.

Purpose of the Study:

• To overcome the 50% yield limitation in preferential crystallization.
• To integrate racemization and recycling steps with PC for enhanced enantiomer recovery.
• To extend the SCM of PC to include kinetic models for racemization reactions.

Main Methods:

• Coupling preferential crystallization with racemization and recycling.
• Extending the shortcut model (SCM) of PC with a kinetic model for enzymatic racemization.
• Utilizing model parameters for asparagine monohydrate resolution and amino acid racemase kinetics.

Main Results:

• Demonstrated various process integration strategies for PC, racemization, and recycling.
• Developed an extended SCM for unified quantification of different process options.
• Highlighted the critical importance of optimal batch stop times for maximizing process productivity.

Conclusions:

• The integration of racemization and recycling effectively overcomes the yield limitations of traditional PC.
• The extended SCM provides a generalized design concept for improved chiral separations.
• Optimizing batch operation parameters, particularly the stop time, is crucial for achieving high productivity in enantiomer resolution.