The kaolin hollow bre membranes were fabricated via the phase inversion process. Fluoroalkylsilanes (FAS) agents were used to improve the surface properties of kaolin membranes.The effect of hydrophobicity nature by using various FAS groups at different times has been investigated. The membrane contactor system has proven its effectiveness in CO 2 separation by the pH values.

The membrane contactor system is one of the most important technologies to trap CO2 from natural gas. To apply this technology, hollow fibre membranes with a superhydrophobic surface must be used. Three types of fluoroalkyl silane (FAS) molecules [C6, C8, C10] at different immersion times (6, 24, 48,72 h) were used to modify kaolin hollow fiber membrane into the superhydrophobic property to capture CO2 from natural gas via contacting gas-liquid system. The kaolin was chosen due to its abundantly available at an affordable price as well as a high amount of groups hydroxyl (OH) in the surface which easily reacts with (FAS) during the grafting process. Superhydrophobicity was distinguished by Fourier transforms infrared (FTIR), scanning electron microscope (SEM), liquid entry pressure of water (LEPw) measurement, and contact angle (CA). The chosen superhydrophobic kaolin membrane was tested for carbon dioxide (CO2) capture via the membrane contactor system. With increasing time of immersion, the hydrophobicity phenomena raised gradually until superhydrophobicity property was obtained. It was proved that the 48 hours was sufficient time to obtain the desired superhydrophobicity property to avoid wetting pores of the membranes. Besides, the perfect type of FAS for separation CO2 was C8 based on sufficient LEPw and contact angle. The reduction of pH was observed after testing the performance of using membrane contactor to separate CO2 by water as absorbent where pH value was reduced from 6.6 to 4.3 within one hour, which concludes that the success of the gas-liquid system to remove CO2 from natural gas.