Preparation of ceramic based hollow fiber composite membrane and its CO2/N2 separation performance

Compared to traditional gas separation methods， membrane separation technology has advantages in low cost， easy operation， and high separation efficiency. In this study， the whisker mullite hollow fiber membrane （M0） with excellent high-temperature resistance， high strength， and large flux was used as the supporting layer. The PDMS with controllable viscosity was used as the intermediate transition layer. The PDMS coated on the surface of M0 and covered the defects on the substrate. Subsequently， the UiO-66-NH2 nanoparticles were modified with amino groups via the hydrothermal method. Trimesoyl chloride was used as the oil-phase monomer， and cysteamine was used as the water-phase monomer for interfacial polymerization. Through this interfacial polymerization process， UiO-66-NH2 was loaded on the top layer of the composite membrane to form the M0-PUi composite membrane. The properties of the membrane before and after modification were characterized by FT-IR， XRD， SEM， and water contact angle of the membrane surface. The CO2/N2 separation performance of the membrane was tested using a self-made gas separation device. The results show that the CO2 permeance of the composite membrane reaches 2765.3 GPU at room-temperature and under 0.2 MPa operating pressure， and its separation selectivity for CO2/N2 is 3.2. The stable separation selectivity of the composite membrane for CO2/N2 is 3.2-3.4 after continuous use at 80 ℃ or 120 ℃ for 6 h.