Characterisation of Romakon™-PM pervaporation membranes for the separation of dilute aqueous alcohol mixtures

•Pervaporation was applied for the separation of real mixtures in the process of beer production.•Novel thin-film composite pervaporation membranes are characterised.•The influence of the structural features of the polyimide in the coating layer on transport properties is discussed.•The influence of the main technological parameters on the process performance is discussed. Thin-film composite pervaporation membranes with selective layer from pyromellitic dianhydride -4,4′ oxydianiline polyimide on porous poly(amide-imide) support (Romakon™-PM) for treatment of water/ethanol mixtures with exceeding water content (>50 wt% water) are characterised by the use of scanning electron microscopy, atomic force microscopy and X-ray diffraction. Membranes showed high values of flux, separation factor and PSI (up to 774) in the selected feed mixture composition range. The influence of the support and structural features of the polyimide in the coating layer on the transport properties is discussed. The membranes are successfully tested in terms of pervaporation dehydration of beer. The influence of the permeate temperature on the separation process performance is discussed.