Functional LSM–ScSZ/NiO–ScSZ dual-layer hollow fibres for partial oxidation of methane

In this study, a functional La0.80Sr0.20MnO3−δ (LSM)–Scandia-Stabilized-Zirconia (ScSZ)/NiO–ScSZ dual-layer hollow fibre has been developed using a single-step co-extrusion and co-sintering process, and has been employed as a dual-layer hollow fibre membrane reactor for partial oxidation of methane. Oxygen permeation rate between 0.49 and 1.82 ml/min and methane conversion between 53.55% and 98.78% have been achieved when operating temperature is elevated from 920 to 1060 °C, together with a significant reduction in coke-deposition. Oxygen permeation through the outer LSM–ScSZ permeation layer (approximately 109.2 μm in thickness) is found to be the controlling step to methane conversion at the operating temperature below 990 °C, above which the excessive oxygen permeation results in formation of CO2 and H2O as by-products. The experimental results further suggest that the amount of NiO in the inner NiO–ScSZ layer should be optimised based on the factors such as catalytic activity/stability, porosity and mechanical strength in addition to the sintering behaviour which has to be matched to the outer LSM–ScSZ layer.