(734c) Polymer Membrane Separations for Microreactors

Membrane separation processes constitute an established variant in downstream processing of the chemical industry, particularly as gas/vapour separations, pervaporation, nanofiltration and membrane contactors. Operating conditions and separation task permitting, in large-scale membrane processes polymeric membranes are preferred over inorganic ones as the latter tend to be less mechanical stress-resistant, resulting in higher maintenance costs. In micro reactor technology, the opposite trend can hitherto be observed. Of the few works dealing with membrane separations in microreactors, most involve inorganic membranes. This may be motivated predominantly by the type of separation, e.g. hydrogen removal, but also by the fact that dimensions are dramatically reduced in comparison to large scale applications. As a consequence, mechanical stability is less of an issue. Polymer membrane separations can nevertheless be an interesting option for micro reactor separations. With an ample range of chemical and physico-chemical properties available for tailoring these membranes toward a particular application, and with the possibility of a straightforward production of large batches which warrants a reproducible selectivity and permeation flux, it will be discussed in this presentation how polymeric membranes may enhance the separation efficiency in microreactors, for example through removal of gases/vapours or reaction by-products. It will also be shown that the use of polymeric membranes in microreactors is not a mere scaling down and transfer of know-how from large-scale processes. For instance, membrane processes offering a high surface-to-volume ratio for mass transfer, such as membrane contactors, might find limited applications in microreactors which boast precisely the same asset. Existing membrane processes therefore require a careful reassessment before introducing them into a microreactor system.

ACKNOWLEDGEMENTS The author would like to thank the European Research Council for funding this work through an IDEAS starting grant (MATRIX-209842).