Fabrication and characterization of developed polysulfone hollow fiber membranes for dehydration of gas streams via gas-liquid membrane contactor

In the present study, developed polysulfone (PSF) hollow fiber membranes were fabricated via a phase-inversion process. In order to enhance the membrane porosity, non-solvent additives such as polyvinylpyrrolidone (PVP) and poly ethyleneglycol (PEG) were introduced into the polymer solutions. The prepared membranes were used in the membrane contactor modules for dehydration of nitrogen gas stream by triethylene glycol (TEG). The membranes were characterized in terms of scanning electron microscopy (SEM), nitrogen permeation, overall porosity, collapsing pressure and wetting pressure. From SEM analysis, the membranes prepared by PVP and PEG presented a porous structure with smaller finger-like cavities compared to the plain membrane. Results of gas permeation test showed that the developed PSF-PVP membrane had mean pore size of 112 nm and N2 permeance of 16900 GPU. Due to open structure of the PSF-PVP membrane, a good overall porosity of about 76% was obtained. The prepared membranes by PVP and PEG showed higher collapsing pressure due to the formation of smaller finger-likes and a thicker spongy sublayer. From dehydration test at liquid flow rate of 250 ml/min, the maximum vapor absorption flux of 6.6×10-7 m3/m2 s was achieved for the PSF-PVP membrane which was about 10% and 6.5% higher than the flux of the plain membrane and PSF-PEG membrane, respectively.