Zeolite-filled regenerated cellulose membranes for pervaporative dehydration of glycerol

Regenerated cellulosic membranes were prepared by dissolving linter pulp in N-methylmorpholine-N-oxide (NMMO) solution with four different cellulose concentrations (3, 5, 8 and 10 wt. % cellulose) at three different coagulation temperatures (5, 25 and 50 degrees C). Zeolite 13 X with an average particle size of 310 nm and Zeolite 4A with an average particle size of 270 nm were added during dissolution. The resulting composite membranes were characterized by Fourier Transform Infrared (FTIR), Thermogravimetric Analyzer (TGA), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). Pervaporation performances of the zeolite filled and unfilled regenerated cellulose membranes were tested for glycerol/water mixture. Chemically and thermally stable regenerated cellulose membranes could be prepared by using submicron sized zeolite loading maximum of 50%. The SEM pictures showed that the zeolite particles in polymer phase were uniformly distributed. It was concluded that the zeolite filled regenerated cellulose membranes have minimum degradation during membrane preparation obtained from NMMO and could be used as pervaporation membranes. At 30 degrees C and with the addition of 20 wt. % Zeolite 13 X to the cellulose membrane, the flux and selectivity was obtained 65 gm(-2)h(-1) and 1681 for 90 wt% glycerol aqueous solution, respectively. (C) 2010 Elsevier Ltd. All rights reserved.