Roll-coating of defect-free membranes with thin selective layer for alcohol permselective pervaporation: From laboratory scale to pilot scale

Abstract

Pervaporation offers advantages over traditional separation processes, but there is still lack of scale-up methods and manufacturing systems to easily and controllably obtain the defect-free membranes. In this work, poly(dimethylsiloxane)/polysulfone composite membranes were scaled up using a roll-coating method. The thickness of the poly(dimethylsiloxane) separation layer was successfully controlled on polysulfone substrate by roll-coating different layers. The membranes are used for separating ethanol/water mixtures. The pervaporation experiments were performed (i) in the laboratory using a radial cell with a membrane area of 0.0028m2; (ii) in a large cell using a plate-and-frame module with membrane area of 0.36m2; and (iii) in a pilot plant located at an industrial site, with a plate-and-frame module and total membrane area of 2.16m2. On-site operations showed that the flux of 1000–1200gm−2h−1 with 60–65wt% ethanol in permeate was achieved by the pilot-scale pervaporation facility, which demonstrated technical feasibility for industrial application.