In this study, 2 types of asymmetric La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) hollow fibre membranes, which consist of conical-shaped microchannels open at the inner surface and an outer dense oxygen separation layer have been developed via a viscous fingering induced phase inversion technique, using different bore fluids such as dimethyl sulphoxide (DMSO) - (M1) and N-methylpyrrolidone (NMP)-ethanol - (M2). The use of these solvent-based bore fluids results in different membrane structures, such as dimensions of the conical-shaped microchannels and thickness ratios between the inner layer with such microchannels and the outer dense separation layer. Apart from the substantially reduced resistance across the membrane, the microchannels act as a structured substrate where catalyst can be deposited for the catalytic reaction to take place. A catalytic hollow fibre membrane microreactor (CHFMMR) can thus be formed after incorporating Bi1.5Y0.3Sm0.2O3-δ (BYS) inside the conical-shaped microchannels of M2 membrane. In contrast to a fixed bed reactor (FBR) and a membrane reactor design where the same catalyst was packed outside the membrane (PBHFMR), the performance of M2-CHFMMR was substantially improved due to the thin oxygen separation layer, great mass transfer inside microchannels where BYS catalyst was coated, efficient delivery of both dissociated and ionized oxygen directly from membrane towards the reaction sites (favourable to forming C2+ and therefore improved C2 yield) etc. Moreover, this study further proves that uniformly dispersing a small amount catalyst inside micro-structured ceramic hollow fibre membranes can be an efficient route to promote the efficiencies of catalytic membrane reactors. Further improvement on C2+ yield and productivity rate can thus be potentially achieved by optimizing reaction conditions.
- Catalytic membrane reactor
- Ceramic hollow fibre membrane
- Viscous fingering induced phase inversion process