Nafion/TiO2 nanoparticle decorated thin film composite hollow fiber membrane for efficient removal of SO2 gas

Abstract

In this work, thin film nanocomposite (TFN) membranes for SO2 gas removal have been fabricated by incorporation of PEBAX and Nafion/TiO2 (hereafter referred as Nf/TiO2) nanoparticles on a polyethersulfone hollow fiber membrane substrate. Membrane structure, inner coating, and thickness were confirmed by SEM cross-sectional images. In addition, morphological and structural analyses of the membranes were performed using FTIR, SEM, EDX, TEM, and AFM. To investigate the effects of Nf/TiO2 nanoparticles on the gas permeation performance, four membrane modules with different mass concentrations of Nf/TiO2 - 0.025, 0.050, 0.075, and 0.1 g - were fabricated. The gas permeation experiments were performed with pure SO2, N-2, and CO2 gases and a mixed gas (SO2/CO2/N-2) within a pressure range of 1-3 bar and feed gas flow rate of 0.03-0.15 L/min. The obtained experimental results suggest that the addition of Nf/TiO2 nanoparticles improved the membrane performance by introducing sulfonate and hydroxyl functional groups to the membrane, and thus increased SO2 permeation and selectivity. The SO2 permeation was found to be 411-1671 GPU in the range of the studied parameters. The ideal selectivities achieved for SO2/N-2 and SO2/CO2 were 2928 and 72, respectively. Overall, an SO2 removal efficiency of 93% was achieved by using the Nf/TiO2 incorporated TFN membrane.