Abstract: Modeling and numerical solution of catalytic reactions in catalytic monolith I will present mathematical modeling for catalytic reactions in a catalytic monolith. The numerical solution for the mathematical model will be shown. The process is modeled using boundary-layer theory, this forms a system of parabolic partial differential equations. The PDE system is discretized using the method of lines, the discretization leads to a large differential algebraic equation system. The detailed chemistry for gas and surface reactions is also considered in the model.