Dynamics of non-isobaric diffusion in porous catalysts

✍ Scribed by M. Novák; K. Ehrhardt; K. Klusáček; P. Schneider

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 893 KB
• Volume: 43
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(88)85030-9

✦ Synopsis

A measuring cell was constructed for determining the time development of total pressure changes inside porous pellets, caused by composition step-change of the gas flowing along one flat face of pellets. Using this cell and swopping of gases in binary systems HZ-N,, H,-Ar, He-N,, He-Ar, experimental pressure response curves were obtained for porous a-alumina pellets with mono-and bidisperse pore structures. Utilizing description of the combined gas transport according to the mean transport-pore model and dusty gas model the pressure responses were simulated numerically. Transport parameters of pellets obtained by fitting experimental responses were compared with parameters determined independently by steady-state methods.-INTRODUCIION Mass transport of gases in porous materials (e.g. heterogenous catalysts, adsorbents, solid reactants etc.) can be isobaric only if the fluxes, Ni, of gas mixture components (with molecular weights Mi) satisfy the Graham's relation (see e.g. Jackson, 1977; Cunningham and Williams, 1980) Z;;, N,(M,)"Z = 0 (1)