抄録
Effective diffusion coefficients in catalyst pellet for nonreacting and reacting systems, C2H4-He and C2H4-H2, respectively, were measured in the same packed bed of catalyst by the use of the frequency response method. For the latter system the diffusion coefficient was also obtained from the effectiveness factor for the hydrogenation of ethylene. No appreciable differences were found between these values.
The effects of pore size distribution on the effective diffusion coefficients for nonreacting and reacting conditions were examined numerically for first-order reactions.For unimodal pore structures, the differences of coefficient for both conditions do not exceed 10% irrespective of size and width of pore distributions. This may also be the case for bimodal pore structure, when the coefficients are evaluated separately for macro and micro pores.
