Fabrication of Bi1.5Y0.3Sm0.2O3–δ–Based Dual–layer Ceramic Hollow Fibre Membranes for Catalytic Reactions

Abstract

In this study, a dual–layer ceramic hollow fibre membrane consisting of two functional layers, i.e. an outer oxygen separation layer (Bi_1.5Y_0.3Sm_0.2O_{3–δ} (BYS)– L_0.8Sr_0.2MnO₃ (LSM)) and an inner catalytic substrate layer (BYS–NiO), has been developed using a single–step co–extrusion and co–sintering technique. The key factors in successful fabrication of such membranes and morphology control have been investigated, in which how to match the sintering behaviours of the two layers is critically important. The use of BYS, a great ionic conducting ceramic, is proved to be efficient in promoting oxygen permeation at lower operating temperatures, when compared with previous counterpart, ((ZrO₂)_0.90(Sc₂O₃)_0.10(ScSZ)–LSM. This demonstrates its potentials in developing new functional dual–layer ceramic hollow fibre membranes. Moreover, the membranes of this type can be used as a highly compact membrane reactor for catalytic reactions, such as partial oxidation of methane (POM) to syngas and methane combustion, because such a reactor design combines oxygen separation (from ambient air) and methane conversion into a single unit, which significantly reduces the reactor volume due to the extremely high surface area/volume of the hollow fibre configuration.