Chiral separation with hybrid processes
The life science industry is one of the most important areas of the chemical industry. The total revenue from sales in the pharmaceutical and agricultural chemical industries for the year 2000 is estimated to be in excess of €20 billion, the greatest share of which comes from the pharmaceutical industry. Optically active intermediates, which are used as chemical building blocks, auxiliaries or advanced intermediates, have an estimated fraction of 15% of the market. The demand for optically active intermediates increases annually by 7-8% and will continually increase because of the growing need of pure chiral substances in the pharmaceutical industry.
The amino acids also belong to the group of these substances. They can be produces as pure enantiomers or as racemic mixtures. The mostly used processes are asymmetrical synthesis, chiral crystallization and liquid-liquid extraction with chiral selectors. However they all have some disadvantages, as for instance high costs, complexity, etc. Therefore, more and more alternative methods, which enable the avoidance of these disadvantages, are investigated. Some of them are selective ultrafiltration, extraction with microemulsions, ligand-exchange chromatography, etc. With the right coupling of these processes a very good enantiomeric resolution with less process steps could be achieved.
The aim of the project is the development of a hydrid process, where the reactive extraction and the reactive sorption are coupled together. As test system amino acids are used.
Thereby the following methods are investigated:
- Extraction with microemulsions
- Ligand-exchange chromatography with chiral mobile phase
- Modified ligand-exchange chromatography with chiral mobile phase and surfactants