The catalytic hydrogenation of vaporized alpha-methylstyrene (AMS) and 1-octene under external transfer control is tested by different interphase mass transfer approaches. The previously reported experimental data on temperature measurements in the single-pellet reactor and the new experimental data in a fixed-bed reactor are analyzed theoretically. The independent diffusion (Fick) approach absolutely failed to fit the experiments. Three methods that take into account multicomponent diffusion (and are based on the Maxwell-Stefan equations) give close results and agree well with the experimental data. Nevertheless, for hydrogenation (or dehydrogenation) of vaporized hydrocarbons the pseudo-binary approach considered in this study is recommended. It is very simple to use even in a case of complex mixture of hydrocarbons and/or several hydrogenation reactions, when general approaches demanded cumbersome matrix operations. Another more fundamental advantage of the pseudo-binary treatment is that the usage of traditional empirical correlations Sh(Re, Sc), Nu(Re, Pr) for gas-solid transfer (which, as a rule, are based on the Chilton-Colburn analogy) gets the solid theoretical background. (C) 2009 Elsevier B.V. All rights reserved.