کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1274185 | 1497509 | 2013 | 16 صفحه PDF | دانلود رایگان |
• The effect of non-ideal internal diffusion and external mass transfer is studied.
• The functionality of the pressure exponent with operating parameters is provided.
• Sieverts law is inadequate to model H2 permeation with strong external resistance.
This paper focuses on the suitability of using a Sieverts-type empirical law to describe hydrogen permeation through Pd-based membranes in the presence of both concentration-dependent hydrogen transport through the selective layer – referred to as “non-ideal” behaviour – and external mass transfer resistance. In particular, the functionality of the pressure exponent with temperature, pressure and membrane thickness is provided, showing that the Sieverts-type empirical law can be used to incorporate the external mass transfer influence just up to a moderate external resistance. The explanation for this fact is recognised in the inadequacy of the Sieverts-type empirical law to describe the behaviour of the flux limited by external resistance for a sufficiently large permeation driving force. The methodology described in this paper is effective also when the permeation-determining steps cannot be established, helping researchers to a correct interpretation of permeation tests in the presence of severe mass transfer resistance.
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Journal: International Journal of Hydrogen Energy - Volume 38, Issue 36, 13 December 2013, Pages 16229–16244