A LUMPED PARAMETER APPROXIMATION TO A GENERAL MODEL FOR CATALYTIC REACTORS

Consideration ig given to the solution of the highly exothermic fixed bed catalytic reactor problem taking into account heat and mass transfer resistances inside the catalyst pellets and across the external fluid film, as well as radial temperature and concentration gradients in the fluid phase. Even on large digital computers, the computation time is excessively long if the sets of differential equations are solved simultaneously. By considering the intra‐particle equations in detail, it is shown that they may be reduced to a lumped parameter form which permits rapid evaluation of an effectiveness factor. The functional dependence of this effectiveness factor is determined primarily by the external film resistance. While still retaining the characteristics of the general problem, the lumped parameter approximation may be solved in a substantially shorter time, thus permitting its use in optimization and control studies. Copyright © 1969 Canadian Society for Chemical Engineering