COMPACTION OF MICROPOROUS MEMBRANES USED IN MEMBRANE DISTILLATION .1.EFFECT ON GAS-PERMEABILITY

Membrane compaction effects are well documented in RO, UF, and gas sep aration, but little attention is paid to compaction effects in micropo rous membrane processes. This paper examines the effects of compaction on the gas permeability of microporous membranes to be used in MD. Co ntrary to what is observed in RO and UF systems where membrane permeab ility is reduced by compaction, limited compaction of microporous memb ranes can result in enhanced permeability. This enhancement is the res ult of decreased membrane thickness, which increases the pressure grad ient across the membrane. An experimental method is devised to determi ne the effects of membrane compaction on permeability, and a theory fo r modifying flux equations to include a parameter for membrane compact ion is introduced.