Novel CO2-Selective Cross-Linked Poly(vinyl alcohol)/Polyvinylpyrrolidone Blend Membrane Containing Amine Carrier for CO2-N2 Separation: Synthesis, Characterization, and Gas Permeation Study

This article reports structural characterizations and gas permeation properties of novel CO2-selective cross-linked thin-film composite poly(vinyl alcohol) (PVA)/polyvinylpyrrolidone (PVP) blend membranes doped with suitable amine carriers. The characterization of the active layer was carried out by thermogravimetric analysis, differential scanning calorimetry, Fourier transform infrared spectroscopy, and X-ray diffraction. Gas streams containing 20% CO2 and 80% N-2 by volume were used to study the transport properties of CO2 (CO2 and N-2 flux, CO2 permeability, and CO2/N-2 selectivity) across the membrane. The effects of active layer thickness (34-87 mum), feed absolute pressure (1.7-6.2 atm), temperature (90-125 degrees C), and sweep side water flow rate (0.02-0.075 cm3/min) on CO2 transport properties across the membrane were analyzed. The maximum CO2/N-2 selectivity of 370 and a CO2 permeability of 1396 barrer were obtained for the composite membrane with 40 mu m active layer thickness at 2.8 atm feed side absolute pressure and 100 degrees C.