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A kinetic theory of catalysis and mass transfer in a cylinder
Author(s) -
Shendalman L. H.
Publication year - 1968
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.690140411
Subject(s) - mass transfer , thermal diffusivity , sublimation (psychology) , thermodynamics , chemistry , isothermal process , knudsen number , cylinder , mechanics , physics , mathematics , geometry , psychology , psychotherapist
The diffusion and mass transfer of a trace component in a background gas in a cylinder, is treated according to a relaxation transport equation. The system is assumed isothermal and at rest. An expression for an effective axial diffusivity is found which goes to the appropriate high and low density limits. Numerically, this diffusivity is similar to one half of the harmonic mean of the high density diffusivities, which is often used as an empirical extrapolating formula. The radial mass transfer problem results in an integral equation which is solved numerically for all Knudsen numbers. The case of catalytic reaction on the walls is considered in detail. Rarefaction effects become important under conditions of fast reaction. The problem of sublimation or evaporation from a cylinder wall can be treated by the same equations.