MASS AND ENERGY TRANSPORT IN POROUS, GRANULAR CATALYSTS IN MULTICOMPONENT AND MULTIREACTION SYSTEMS.

A mathematical model for multicomponent mass and energy transport in a pseudohomogeneous, isotropic, porous medium with multireactions is formulated. From theoretical considerations, necessary and sufficient conditions to guarantee stoichiometry and the conservation of mass and energy are determined for catalyst particles of any shape. A quantitative method is described, on the basis of the dusty-gas model, for examining a process in the form of a system of partial differential equations, and a method of solution is presented. The model is then applied to the processes inside a granular, ammonia-synthesis catalyst, and an expression is given for the effectiveness factor of the catalyst as a function of the Thiele modulus for the entire range of the parameters of flow.