Supported Liquid Membranes Process Design

In this paper an overview of the developments in liquid membrane extraction of cephalosporin antibiotics has been presented. The principle of reactive extraction via the so-called liquid-liquid ion exchange extraction mechanism can be exploited to develop liquid membrane processes for extraction of cephalosporin antibiotics. The mathematical models that have been used to simulate experimental data have been discussed. Emulsion liquid membrane and supported liquid membrane could provide high extraction flux for cephalosporins, but stability problems need to be fully resolved for process application. Non-dispersive extraction in hollow fib er membrane is likely to offer an attractive alternative in this respect. The applicability of the liquid membrane process has been discussed from process engineering and design considerations. 

Recent developments in LM module design, including rotational, vibrational membrane devices, pulsed-flow fluid management for polarization control, use of low-cost refractory monoliths as membrane supports, and use of electric potentials to minimize macrosolute polarization and fouling, may permit practical and economic application of membrane processes to liquid and gaseous streams which today are untreatable by such methods. 

Development of additional experimental procedures for measuring transport rates. Most of the Instrumental designs available are elaborate and/or expensive. Transport of permeates contained within liquid phases as well as in the gas phase roust be considered. Development of membrane support materials that provide greater stability than ILM s but still allow the systematic incorporation of carriers. Far greater understanding of dlffuslonal processes and chemical reactions within lEM s Is essential. The necessity for In situ experimental techniques was discussed In the previous section. 

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