(612c) A Tubular Membrane-in-a-Shell Microextractor for Continuous Separation of Antibiotic Precursors

Continuous separation and purification of fine chemicals represent a challenging task of chemical and pharmaceutical engineering. Current slug-flow and parallel-flow microfluidic extractors suffer from several disadvantages such as the instability of the liquid-liquid interface or difficult realization of the counter-current arrangement. Hence, we designed and constructed a robust microfluidic extractor with a cylindrical membrane allowing for the integration with other unit operations to provide a continuous steady-state production. The microextractor was tested for the separation of 7-aminodeacetoxycephalosporanic acid (7-ADCA), an important precursor of β-lactam antibiotics. Aqueous two-phase system (ATPS) and a system of identical aqueous phases were used in a series of extraction experiments. We found that the counter-current arrangement is able to provide almost 100 % yield of 7-ADCA. In addition, we observed that the presented tube-in-a-shell microextractor does not require phase separation at the output and guarantees regular and reproducible flow along both sides of the cylindrical membrane. An enhanced enrichment of 7-ADCA expected in ATPS due to favorable partitioning was only reached at longer residence times. Lower mass transport resistances occurring in low-viscous aqueous phases turned out to have a primary effect on the extraction characteristics. A detailed analysis of transport resistances in the microextractor revealed that the contribution of the cylindrical membrane to the overall mass transport resistance is low. This important finding indicates that microcontactors with thin integrated membranes represent a promising option for micro- or milli-plants when fine chemicals would be continuously produced.

References

• Sauer L., Kralik D., Izak P., Slouka Z., Pribyl M.: Effects of aqueous systems and stabilization membranes on the separation of an antibiotic precursor in a microextractor, Separation and Purification Technology 2022, in press

Acknowledgement: The authors thank for the support by the grant of the Czech Science Foundation (grant no. 20-09980S).