Modelling of the Oxygen Transport through MIEC Membrane in Transient Stage

Article Preview

Abstract:

The transient stage is critical due to the stress induced by the chemical and thermal strain. In order to predict this strain, the oxygen activity field through the membrane needs to be known. Usually, the membrane is divided into three zones: the bulk where diffusion takes place and the two surfaces where exchanges between atmosphere and membrane take place. Oxygen bulk diffusion is well described by the Wagner theory. A consensus has not yet emerged regarding the surface exchange models proposed in the literature. Moreover, these models describe the permanent state, and cannot be extended to the transient stage. A new macroscopic surface exchange model which allows computing transient stage is proposed. This model assumed that the oxygen flux is governed by the association/dissociation of adsorbed oxygen and by the high energetic cost of oxygen reduction/oxidation. Then, the balance of transient specie only present on the surface is introduced to account for these two phenomena. The oxygen activity fields predicted by the proposed model are in agreement with the measures of chemical potential drop between the membrane and the atmosphere in permanent state. Transient stage measured during isothermal expansion test is partially reproduced.

You might also be interested in these eBooks

Info:

Periodical:

Pages:

72-77

Citation:

Online since:

October 2014

Export:

Price:

Permissions CCC:

Permissions PLS:

Сopyright:

© 2014 Trans Tech Publications Ltd. All Rights Reserved

Share:

Citation:

* - Corresponding Author

[1] S. Pei, M.S. Kleefisch, T.P. Kobylinski, J. Faber, C.A. Udovich., Failure mechanisms of ceramic membrane reactors in partial oxidation of methane to synthesis gas, Catal. Lett., 30 (1995) 201–212.

DOI: 10.1007/bf00813686

Google Scholar

[2] J. Sunarso, S. Baumann, J.M. Serra, W.A. Meulenberg, S. Liu, Y.S. Lin, J.C. Diniz da Costa, Mixed ionic–electronic conducting (MIEC) ceramic-based membranes for oxygen separation, J. Membr. Sci., 320 (2008) 13-41.

DOI: 10.1016/j.memsci.2008.03.074

Google Scholar

[3] H.J.M. Bouwmeester, H. Kruidhof, A.J. Burggraaf, Importance of the surface exchange kinetics as rate limiting step in oxygen permeation through mixed-conducting oxides, Solid States State Ionics, 72 (1994) 185-194.

DOI: 10.1016/0167-2738(94)90145-7

Google Scholar

[4] S. J. Xu, W.J. Thomson, Oxygen permeation rates through ion-conducting perovskite membranes, Chem Eng Sci, 54 (1999) 3839-3850.

DOI: 10.1016/s0009-2509(99)00015-9

Google Scholar

[5] S. Kim, Y.L. Yang, A.J. Jacobson, B. Abeles, Oxygen surface exchange in mixed ionic electronic conductor membranes, Solid State Ionics, 121 (1999) 31-36.

DOI: 10.1016/s0167-2738(98)00389-0

Google Scholar

[6] O. Valentin, E. Blond, A. Julian, N. Richet, Loading path effect on the chemical expansion in substoichiometric LSF based Perovskite, Comp Mater Sci, 46 (2009) 912-920.

DOI: 10.1016/j.commatsci.2009.04.045

Google Scholar

[7] S.B. Adler, X.Y. Chen, JR. Wilson, Mechanisms and rate laws for oxygen exchange on mixed-conducting oxide surfaces, J Catal, 245 (2007) 91-109.

DOI: 10.1016/j.jcat.2006.09.019

Google Scholar

[8] P.M. Geffroy, A. Vivet, J. Fouletier, N. Richet, P. Del Gallo, T. Chartier, Influence of oxygen surface exchanges on oxygen semi-permeation through La(1-x)SrxFe(1-y)GayO3-δ dense membrane, J Electrochem Soc, 158 (2011) 1-9.

DOI: 10.1149/1.3597086

Google Scholar

[9] C. Wagner, Equations for transport in solid oxides and sulfides of transition metals, Prog Solid State Ch, 10 (1975) 3-16.

DOI: 10.1016/0079-6786(75)90002-3

Google Scholar

[10] A.T. DeMartini, A. Unemoto, T. Kawada, S.B. Adler, Nonlinear Analysis of the Oxygen Surface Reaction and Thermodynamic Behavior of La1-xSrxCoO3-δ, ECS Transactions, 16 (2009) 47-67.

DOI: 10.1149/ma2008-02/13/1309

Google Scholar

[11] S.B. Adler, Chemical expansivity of electrochemical ceramics, J. Am. Ceram. Soc., 84 (2001) 2117-2119.

Google Scholar