Long-Term Stability of PVDF-SiO2-HDTMS Composite Hollow Fiber Membrane For Carbon Dioxide Absorption in Gas–Liquid Contacting Process

To obtain a long-term stable operation of the hollow fiber membrane for using in membrane contact absorption of carbon dioxide (CO2), hybrid polyvinylidene fluoride-silica-hexadecyltrimethoxysilane (PVDF-SiO2-HDTMS) membrane were fabricated via the non-solvent induced phase-inversion method. The surface properties, performance characteristics and long-term stable operation performance of the prepared membranes were compared and analyzed. The results show the outer surface of the prepared membranes exhibited superhydrophobicity because of the formation of rough nano-scale microstructures and the low surface free energy. Due to the addition of inorganic nanoparticles, the mechanical strength of PVDF-SiO2-HDTMS membranes were improved. The long-term stable operation experiments were carried out with the inlet gas (CO2/N2 = 19/81, v/v) at a flow rate of 20 mL/min and the absorbent liquid (1 mol/L DEA) at a flow rate of 50 mL/min. And the result showed that the mass transfer flux of PVDF-SiO2-HDTMS membrane decreased from the initial value of 2.39×10-3 mol/m2s to 2.31×10-3 mol/m2s, which was a decrease of 3% after 20 days. The main benefit is the addition of inorganic nanoparticles, which have strong chemical resistance and high hydrophobicity, thereby preventing structural damage and pore wetting of the membrane. PVDF-SiO2-HDTMS membrane exhibits excellent long-term stable operation performance of CO2.