An Experimental Study PVDF and PSF Hollow Fiber Membranes for Chemical Absorption Carbon Dioxide

Abstract

Poly(vinylidene fluoride) (PVDF) and Polysulfone (PSF) polymer solutions were made at a concentration of 18% by weight of the polymer as a non-soluble additive in polymer solution in 1-methyl-2-pyrrolidone (NMP) solvent. PVDF and PSF hollow fiber membranes were fabricated via the wet phase-inversion process. Fabricated membranes were characterized in terms of gas permeability, wetting resistance, water contact angle, and overall porosity. In order to study the structure of the membranes made, the scanning electron microscopy images of the model (TM3000, Hitachi, Japan) were used. The morphology study indicates that the PSF membrane shows an open cross-section structure with smaller pore sizes. However, the PVDF membrane illustrates a thick sponge-like structure. The fabricated PVDF membrane shows higher wetting resistance, surface porosity, water contact angle, and N₂ permeability. The performance of the produced membranes was examined for the absorption of carbon dioxide in a gas-liquid contactor membrane through the solution of Monoethanolamine (MEA). The results show that the CO₂ absorption flux of the PVDF hollow fiber membrane is higher than that of the PSF hollow fiber membrane. The maximum CO₂ absorption flux of 8.10 × 10^-3 (mol·m^-2·s^-1) at the liquid phase flow rate of 300 mL·min^-1 for PVDF hollow fiber membrane was achieved, and the maximum CO₂ absorption flux of 6.50 × 10^-3 (mol·m^-2·s^-1) at the liquid phase flow rate of 300 mL·min^-1 for the PSF hollow fiber membrane was obtained. It can be concluded that a porous hydrophobic hollow fiber membrane with high surface porosity and high gas permeability can be a productive alternative for CO₂ absorption through gas-liquid membrane contactors.