Membrane distillation for propanone removal from aqueous streams

The use of air-gap membrane distillation for the selective removal of propa none from aqueous solutions was tested. The effect of the following operati ng conditions upon flux and selectivity was experimentally examined: feed c oncentration, feed flow rate, feed temperature, and coolant temperature. Al though the PVDF membranes tested performed well at the propanone feed conce ntrations encountered in fermentation processes, they demonstrated wetting limitations at higher concentrations. Within the feed temperature range of 40-70 degrees C, and propanone concentration up to 6 wt%, propanone selecti vities of 2-6 were achieved. A mathematical model of the process was develo ped and validated. (C) 2000 Society of Chemical Industry.