Preparation, characterization and laboratory-scale application of modified hydrophobic aluminum oxide hollow fiber membrane for CO2 capture using H2O as low-cost absorbent

Abstract

The objective of this work was to apply the modified hydrophobic metal oxide hollow fiber membrane in a laboratory-scale gas–liquid membrane contacting process for CO2 capture applications using H2O as low-cost absorbent at room temperature. With this aim, the porous aluminum oxide (α-Al2O3) hollow fiber membranes were prepared by a phase inversion spinning technique and a sintering method. In order to render the hydrophilic surface of prepared Al2O3 hollow fiber membrane without changing its physical properties, a fluoroalkylsilanes (FAS) film was used. The fluoroalkylsilanized Al2O3 hollow fiber membrane surface was studied by performing thermal gravimetric analysis (TG), scanning electron microscopy (SEM), X-ray diffractometer (XRD). In addition, the hydrophobicity nature of modified Al2O3 hollow fiber membrane surfaces was measured by water drop contact angle test and break through pressure measurement. This work, for what we believe to be the first time, has successfully realized a room-temperature laboratory-scale gas–liquid membrane contactors using a single fluoroalkylsilanized Al2O3 hollow fiber membrane for CO2 capture. According to the experimental results, the correlations between water and gas flow rate, and CO2 mass transfer through the modified hydrophobic Al2O3 hollow fiber membranes are given. In addition, a comparative review was made between our modified hydrophobic aluminum oxide and traditional polymeric hollow fiber membrane for application in the field of CO2 absorption in water. The results indicated that studied fluoroalkylsilanized Al2O3 hollow fiber membrane may be possible candidates for the development of new gas–liquid membrane contactors for CO2 capture.