Novel high free-volume membranes based on poly(bis-SiMe3-tricyclononene) for the pervaporation of ethanol/water mixtures

ervaporation (PV) demonstrates unique advantages over conventional techniques in separating heat-sensitive, close-boiling azeotropic and isomer mixtures. A typical application of organophilic PV is the treatment of fermentative production of bio-alcohols. Removal of the ethanol from the fermentation broth through selective PV membrane represents an effective solution to overcome product inhibition and to shift the production from a batch to a semi-continuous process. In the present work, membranes based on a novel polymer, i.e. poly(bis-SiMe3-tricyclononene) (Ad-PTCN-2Si) are for the first time used for the ethanol/water PV. The highest ethanol selectivity was observed at the ethanol concentration of 5% (a=4.92) with a permeability of 9.0 mm kg/h m2. These values are interesting if compared with those reported in literature for pure and/or mixed matrix membranes based on PDMS.