Diffusion and Heterogeneous Reaction in Porous Media

In this chapter we consider the process of bulk diffusion in a porous catalyst with heterogeneous, first order, irreversible reaction. Simultaneous diffusion and reaction occurs in such diverse systems as porous catalysts, (Jackson, 1977), soil aggregates (Rappoldt, 1990), and biofilms (Wood and Whitaker, 1998), and our objective in this chapter is to illustrate a general procedure by which governing point equations and boundary conditions for diffusion and reaction can be spatially smoothed to produce continuum models for multiphase systems.