Simple numerical scheme for solving the impregnation equations in a porous pellet

This paper proposes a numerical scheme for solving a system of convection-reaction-diffusion equations describing the process of preparing a catalyst on a porous support by the impregnation method. In the case of a considered porous spherical pellet, the equations are defined on an interval, one end of which, associated with the front of the impregnating liquid, moves according to a given law. The law of front motion is used to create a consistent space-time grid for discretizing the system. Examples of numerical solutions of the impregnation problem are given, demonstrating the effectiveness of the proposed scheme.