Pervaporation performance of PDMS-Ni 2+Y zeolite hybrid membranes in the desulfurization of gasoline

Abstract

PDMS-Ni 2+Y zeolite hybrid membranes were fabricated and used for the pervaporation removal of thiophene from model gasoline system. The structural morphology, mechanical stability, crystallinity, and free volume characteristics of the hybrid membranes were systematically investigated. Molecular dynamics simulation was employed to calculate the diffusion coefficients of small penetrants in the polymer matrix and the zeolite. The effect of Ni 2+Y zeolite content on pervaporation performance was evaluated experimentally. With the increase of Ni 2+Y zeolite content, the permeation flux increased continuously, while the enrichment factor first increased and then decreased possibly due to the occurrence of defective voids within organic–inorganic interface region. The PDMS membrane containing 5.0 wt% Ni 2+Y zeolite exhibited the highest enrichment factor (4.84) with a permeation flux of 3.26 kg/(m 2 h) for 500 ppm sulfur in feed at 30 °C. The effects of operating conditions on the pervaporation performance were investigated in detail. It has been found that the interfacial morphology strongly influenced the separation performance of the hybrid membrane, and it was of great significance to rationally modify the interfacial region in order to improve the organic–inorganic compatibility.