(Invited) Ionic Conducting Ceramic Membranes – Potential Applications - Materials - Components – Transport in Asymmetric Structures

Abstract

Ceramic mixed ionic-electronic conducting membranes can be used for the separation of single gases (e.g hydrogen or oxygen) from gas mixtures or in membrane reactors. Ceramic membrane reactors (CMR) offer an opportunity to combine separation processes directly with chemical reactions, leading to process intensification and, hence, benefits with regard to efficiency. This integral coupling of both processes, separation and reaction, generates synergies between them. Current research activities focus on membrane reactors due to their high intrinsic efficiency and great potential for the production of a large variety of commodity chemicals, energy carriers, and synthetic fuels. This includes the reduction of CO2 emissions and the utilisation/valorisation of CO2. The development of ceramic membrane materials for such devices is focussed on performance and stability (chemical and thermal) in application relevant environment. The operating temperature is between 400-850°C. The presentation covers a series of potential stable materials for oxygen- and hydrogen ion conducting membranes and their characterisation and performance in application oriented conditions. To reach a high performance of the membrane systems thin film membranes, active surface layers and thermochemical and -mechanical stable supports with designed porosity are required. The production and characterization of membrane structures is explained using the example of sequentially tape cast and laminated supported membranes. Furthermore, the ion and gas transport through such supported thin membranes is described and an example of transport modelling will be given. Finally, the construction of a Proof of Concept membrane reactor for oxygen separation in oxyfuel cement industry or the use in fossil fuelled power plants will be shown. The lecture concludes with an outlook on future development directions.