Surface exchange model for ITM membrane in transient stage

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.

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Description and initial simulation of a dynamic bidirectional air-surface exchange model for mercury in Community Multiscale Air Quality (CMAQ) model

Journal of Geophysical Research Atmospheres ◽

10.1029/2009jd012834 ◽

2010 ◽

Vol 115 (D6) ◽

Cited By ~ 45

Author(s):

Jesse O. Bash

Keyword(s):

Air Quality ◽

Exchange Model ◽

Surface Exchange

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Measuring the oxygen profile and permeation flux across an ion transport (La0.9Ca0.1FeO3−δ) membrane and the development and validation of a multistep surface exchange model

Journal of Membrane Science ◽

10.1016/j.memsci.2014.05.043 ◽

2014 ◽

Vol 468 ◽

pp. 62-72 ◽

Cited By ~ 33

Author(s):

Anton Hunt ◽

Georgios Dimitrakopoulos ◽

Patrick Kirchen ◽

Ahmed F. Ghoniem

Keyword(s):

Ion Transport ◽

Exchange Model ◽

Permeation Flux ◽

Surface Exchange ◽

Oxygen Profile ◽

Development And Validation

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Thermo-Chemo-Mechanical Modelling of Mixed Conductors in Transient Stages

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.65.232 ◽

2010 ◽

Vol 65 ◽

pp. 232-237 ◽

Cited By ~ 10

Author(s):

Olivier Valentin ◽

Eric Blond ◽

Nicolas Richet

Keyword(s):

Mechanical Stress ◽

Bulk Diffusion ◽

Oxygen Flux ◽

Surface Exchange ◽

Transient Stage ◽

Chemical Expansion ◽

Permeation Transient ◽

Exchange Kinetics ◽

The Impact ◽

The Relationship

This study deals with the modelling of the mechanical behaviour accounting for the expansion induced by the oxygen diffusion in MIECs membrane during semi-permeation transient stage. A dedicated model of chemical expansion and its numerical implementation is used to study the relationship between the mechanical stress and the oxygen flux. The impact of the ratio between oxygen bulk diffusion and surface exchange kinetics on mechanical stress in transient stage is discussed. At last, the need of a compromise between the oxygen flux performance and the mechanical reliability is underlined.

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