Pervaporative desulfurization of n-heptane/thiophene model gasoline for modified polyether-block-amide (Pebax) membrane

Polyether-block-amide (Pebax) is a novel membrane material for pervaporative (PV) desulfurization of gasoline. In order to improve its desulfurization performance, Pebax was doubly modified by blending of perfluorosulfonic acid (PFSA) and hybridization of Si sol in this study, and Pebax-PFSA-Si hybrid membrane was fabricated. The hybrid membrane was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Polyacrylonitrile (PAN) ultrafiltration (UF) membrane as support, Pebax-PFSA-Si/PAN composite membrane was fabricated using coating method for PV desulfurization of n-heptane/thiophene mixtures. The incorporation of Si sol increased the cross-linking degree of Pebax-PFSA membrane, effectively inhibiting the excessive swelling of membrane. The dynamic absorption behavior of Pebax-PFSA-Si hybrid membrane was investigated. The degree of swelling (DS) of membrane increased with an increase of thiophene concentration in the feed. Effects of membrane compositions and operational variables such as feed temperature, feed sulfur concentration on desulfurization performance of Pebax-PFSA-Si/PAN composite membrane were investigated. Compared with Pebax membrane, Pebax-PFSA-Si/PAN membrane had the higher permeation flux because of the blending of PFSA and the higher enrichment factor due to the hybridization by Si sol.