Effect of extrusion temperature on PP hollow fiber membrane properties and its CO₂ degassing performance

It is challenging to remove low concentration CO₂ from water. Membrane degassing has potential advantages in degassing from water. In this paper, PP hollow fiber membrane (HFM) was prepared via TIPS method using carnauba wax (Cwax) and soybean oil (SO) as binary green diluents. The effects of extrusion temperature on the membrane properties were studied. The results showed that when the extrusion temperature increased from 155 C to 170 C, the membrane pore size first increased and then decreased, and the maximum value was obtained at 165 C. The extrusion temperature had little effect on morphology and liquid entry pressure (LEP) of the membrane. Considering the pore size and LEP synthetically, the optimized PP HFM was prepared at the extrusion temperature of 170 C, and fabricated into the membrane module. The CO₂ degassing performance from the water in RO system was studied. The results showed that the degassing efficiency (η) decreased as the water flow rate increased, which was mainly due to the decreasing water residence time in the membrane module. When the effective membrane length increased to 4.41 m, the η was almost stable at 80%.