Integrated Simulated Moving Bed Processes for Production of Single Enantiomers

Based on the assumption of true moving bed processes it was demonstrated that integration of a racemization reaction into a continuous chromatographic process can improve the production of single enantiomers. In view of possible practical implementations, the analysis is extended to more realistic simulated moving bed (SMB) processes. Superstructures of SMB‐based systems are defined that reflect the three general concepts of flow sheet, partial, and total process integration. Process candidates are generated by simultaneously optimizing process structure and operating conditions. Optimal process setups are determined under idealized conditions as a function of the purity requirement. The best performance is achieved by fully integrated processes. These are compared under more realistic conditions to units with side reactors. The results indicate that a simple fully integrated SMB system with three zones is a particularly promising new process option. The new concept is investigated in detail to identify relevant practical aspects. New and existing integrated processes using simulated moving bed (SMB) chromatography are investigated for production of single enantiomers. Process superstructures are optimized by an MINLP approach to evaluate the large number of possible setups using either a separator‐reactor‐recycle system, side reactors, or chromatographic reactors. A new integrated three‐zone SMB system is studied in detail.