SIPS 2018

DETAILLED PROGRAM OVERVIEW

MIEC-type A2BO4 Ceramic Membranes with Enhanced Oxygen Permeation
Konrad Swierczek¹;
¹AGH UNIVERSITY OF SCIENCE AND TECHNOLOGY, FACULTY OF ENERGY AND FUELS, Krakow, Poland;
PAPER: 194/AdvancedMaterials/Regular (Oral)
SCHEDULED: 16:45/Wed./Guaratiba (60/2nd)

ABSTRACT:
Membrane technology is successfully commercialized in various industrial applications, e.g. in treatment of chemicals, food, gas, water or wastewater. Recently it has also emerged in clean and renewable power applications [1]. In particular, dense ceramic membranes having mixed ionic-electronic conductivity (MIEC) can be used for the production of a high purity hydrogen and oxygen via gas separation route, but also for preparation and processing of syngas, e.g. by a partial oxidation of methane. Such membranes can be applied as well in gas separation technology [2]. For instance, oxygen can be preferentially transferred from a gas mixture through the MIEC membrane, allowing to obtain a high-purity O2 for further usage. Many considered MIEC-type oxides, candidate membrane materials which exhibit high mixed ionic-electronic transport properties, and possess either perovskite-type or perovskite-related crystal structure. In such compounds, the electronic component of the electrical conductivity is governed by a double exchange mechanism, while the ionic component in ABO3-δ perovskite-type oxides proceeds by the oxygen vacancy mechanism. However, depending on the chemical composition, temperature, and the oxygen partial pressure, A2BO4±δ compounds may exhibit ionic transport through the oxygen vacancies or the interstitial oxygen. Movement of the interstitial oxygen is unique, due to a low activation energy but also nature of the transport, which is described as the interstitialcy mechanism [3, 4]. Unfortunately, due to the 2D-type conduction in A2BO4±δ, the observed macroscopic conductivity of polycrystalline sinters is relatively low. In this work, various approaches are discussed concerning methods of enhancement of the oxygen permeation through A2BO4±δ ceramic membranes, including preparation of a functional layer having 3D conductivity and introduction of the A-site nonstoichiometry and the B-site doping. It is shown that the A-site deficient A2-xCu1-yNiyMzO4±δ (A - larger lanthanides, M - Sc3+, Ga3+) possess excellent transport properties, and are a suitable basis for the development of a highly-conducting, barium-free, dense ceramic membranes, which can be further enhanced with the functional layer.

References:
[1] A. Gugliuzza, A. Basile (Editors), Membranes For Clean And Renewable Power Applications, Woodhead Publishing Limited, 2014.
[2] K. Li, Ceramic Membranes For Separation And Reaction, John Wiley & Sons Ltd, 2007.
[3] A.C. Tomkiewicz, M. Tamimi, A. Huq, S. McIntosh, J. Mater. Chem. A 3 (2015) 21864.
[4] T. Ishihara (Editor), Perovskite Oxide for Solid Oxide Fuel Cells, Springer, 2009.