Asymmetric temperature and composition profiles in catalyst particles

[摘要] In the many published discussions of chemical reactions accompanied by heat conduction and diffusion in catalyst particles, it has been tacitly assumed that the temperature and concentration profiles have the symmetry of the particle. It is the main purpose of this work to show that this is not necessarily the case, and hence, that the extensive literature on multiple solutions has uncovered only a fraction of all possible steady states. A slab has been used as a model for the catalyst particle? diffusive resistances to heat and mass flux in its interior and Newtonian resistances to heat and mass transfer at its faces has been considered. For a single first order exothermic reaction with Arrhenius temperature dependence and constant thermal and mass diffusivities, asymmetric profiles for temperature and composition have been obtained, thus verifying the above contention.

[发布机构] Rice University