Oxygen permeation through thin mixed-conducting solid oxide membranes

Journal Article · Sun May 01 00:00:00 EDT 1994 · AIChE Journal (American Institute of Chemical Engineers); (United States)

DOI:https://doi.org/10.1002/aic.690400506· OSTI ID:7004232

Lin, Y S; Wang, W; Han, J ^[1]

---

1. Univ. of Cincinnati, OH (United States). Dept. of Chemical Engineering

A new approach for developing fundamental equations of oxygen permeation through thin mixed-conducting oxide ceramic is presented considering both surface reactions on membrane-gas interfaces and the diffusion of charged species in the bulk oxide. The essence of this work is the coupling of surface reactions with bulk diffusion using a novel approach which differs from the conventional Wagner theory applicable only to limited cases. With this approach, fundamental equations based on various permeation mechanisms can be derived for oxygen permeation through thin mixed-conducting oxide membranes, which is impossible using conventional approach. In general, the final results are a complex implicit equation correlating the oxygen permeation flux to the driving force, membrane thickness, and rate constants with physical significance in each step. Somewhat simpler theoretical oxygen permeation equations are obtained for some special cases (mixed-conducting membranes with a rate-limiting step, ionic-conducting membranes, ionic-conducting membranes with a reducing agent in permeate side). Theoretical results derived using this new approach agree excellently with the experimental oxygen permeation data. It is theoretically and experimentally shown that for ionic conductors, the surface permeation parameter measured by the dynamic permeation method is directly related to the oxygen isotope exchange rate constant measured under equilibrium conditions.

• OSTI ID: 7004232
• Journal Information: AIChE Journal (American Institute of Chemical Engineers); (United States), Journal Name: AIChE Journal (American Institute of Chemical Engineers); (United States) Vol. 40:5; ISSN 0001-1541; ISSN AICEAC
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400105* -- Separation Procedures
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTROLYTES
ELEMENTS
IONIC CONDUCTIVITY
MATHEMATICAL MODELS
MEMBRANE TRANSPORT
NONMETALS
OXYGEN
PERMEABILITY
PHYSICAL PROPERTIES
SEPARATION PROCESSES
SOLID ELECTROLYTES