Effects of different hollow fiber membrane modules on bubbleless aeration of methane and oxygen

To explore the possibility of bubble-free membrane aeration in the biotransfer of methane safely and efficiently, the effects of hollow fiber membrane modules on the mass transfer rates of methane and oxygen were examined in this work. Three membrane modules, dens silicone membrane (A), hydrophobic micro porous polypropylene membrane (B), and hydrophilic micro porous poly(ether sulfide) membrane (C), were investigated. The investigation results show that the gas-liquid mass transfer rates of methane and oxygen can be improved significantly for modules A and B. For the bubble less aeration of methane (for the case that methane is bubble less aerated), the volumetric mass transfer coefficients (K_La) of methane for modules A and B are 3.19 and 3.78 h^-1, respectively, which are 3 times of that for the conventional bubble aeration. For the bubble less aeration of air (for the case that air is bubble less aerated), K_La of oxygen for nodule B is 61.1 h^-1, which is 2.6 times of that for module A and 24.8 times of that for the conventional bubble aeration.