Papers by Author: A.F. Ismail

Abstract: Helium is one of the most valuable gases with unique features and properties as well as widely used in various applications. Generally, most of the helium sources was extracted from natural gas and it is very crucial to develop efficient technology for helium recovery from natural gas sources, in order to overcome the deficit of the helium supply. Up to now, there are various available traditional separation methods for helium recovery, however these methods possessed several disadvantages such as expensive in cost and energy intensive. Recently, gas separation by using membranes have been utilized and showed potential in recovering and purifying helium from natural gas. This method directly separating the helium from the methane through natural gas liquefaction process where in this process the helium is recovered from the nitrogen rejection unit (NRU) exit gas. Due to the potential benefits that can be obtained from this membrane-based separation method, this current study is aiming to provide more comprehensive scientific reports on the effects of preparation parameters on the performance of tubular carbon membranes (TCMs) for helium separation. In this study, the carbonization heating rate was varied from 1 to 7°C/min by controlling the final temperature at 800°C under Argon environment for all polymeric tubular membranes. The permeation performance of the resultant TCMs have been determined by using a single permeation apparatus. It is necessary to fine-tuning the carbonization conditions in order to obtain the desired permeation properties. From the results, it can be concluded that the most optimum heating rate was found to be at 3°C/min with 463.86±3.12 selectivity of He/N₂ separation.

Abstract: Alumina hollow fiber membrane with asymmetric structure has been developed using phase inversion technique followed by sintering process. The formation of asymmetric alumina hollow fiber was influenced by a phenomenon known as hydrodynamically unstable viscous fingering. A desired morphology of the ceramic hollow fiber membrane, that consists of 52 % of finger-like and the rest is sponge-like structure, is tailored by controlled parameters during membrane fabrication process. The result shows that the ratio of alumina/PESf should be reduced to 6. At this ratio, the finger-like structure can be easily formed with inner and outer diameters were 1.11 mm and 2.05 mm respectively. From the given thickness, approximately 243 µm of finger-like length can be developed originating from the lumen of hollow fiber.

Abstract: This study was to investigate the properties of the sulfonated poly(ether ether ketone) (SPEEK) nanocomposite membranes filled with Cloisite 15A® clay, in the presence of 2,4,6 triaminopyrimidine (TAP) as a compatibilizer. The membranes were prepared via solution intercalation method, before they were subjected to performance tests in the temperature range of 27 to 80 oC for comparison with Nafion® 117. The SPEEK membranes were then utilized to measure the open circuit voltage (OCV) and power density for direct methanol fuel cell (DMFC) applications in the temperature range of 27 to 60 oC. The best data obtained, among all the tested membranes, were methanol permeability of 0.52 ×10-6 cm2s-1 and proton conductivity of 47 mScm-1 with the methanol selectivity of 9.1 × 104 S.s.cm-3, even at a high temperature of 60oC.