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Deviation from the inverse‐thickness relation in gas‐metal permeation
Author(s) -
Phillips J. R.,
Dodge B. F.
Publication year - 1963
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690090121
Subject(s) - permeation , membrane , hydrogen , chemistry , metal , analytical chemistry (journal) , materials science , thermodynamics , chromatography , physics , organic chemistry , biochemistry
The permeation rate of hydrogen through cylindrical membranes of type 321 stainless steel was determined under a wide range of conditions. The pressure was varied from 0.1 to 30.0 atm. and the temperature from 300° to 800°C. Four permeation membranes were used with wall thicknesses of 0.0252, 0.1003, 0.1011, and 0.2475 cm. The permeation rate was found to deviate from the square‐root‐of‐pressure and inverse‐thickness relations predicted by the Richardson equation. Slow surface reactions are considered to be the cause of the observed deviations. The permeation data were correlated by a semiempirical interfacial resistance model. Permeation rates were observed to increase with time of membrane exposure to hydrogen. It is believed this resulted from changing surface activity.