Efficient membrane-based affinity separations for chemical applications: A review

This review examines the recent trends and developments in membrane-based extraction technology, with a focus on supported liquid membrane (SLM) extraction. This paper attempts to review the studies on polymeric membrane extraction, relating to mass transfer, stability, fluxes and performance. Prospects for future research, on the use of membrane extraction for in-situ product removal of chiral amines, are presented as well. The main challenge of the current state-of-the-art membrane extraction technology is limited SLM-stability. Conventionally, polymeric membrane materials are used as an SLM-support. The use of ceramic membranes, either with or without surface modification, should be looked at as a possible means of stability enhancement. The use of ionic liquids as the solvent for membrane impregnation is already studied intensively in literature. However, the performance of a certain IL is strongly dependent on the system at hand. Techniques such as hollow fibre renewal liquid membranes and polymer inclusion membranes, can also increase membrane stability and are discussed further. Lastly, the industrial application potential of membrane extraction is hindered by the lack of scaled-up pilot plants, which is addressed as well.