A catalytic distillation model, based on Maxwel-Stefan Equations, is presented. In this model, the effective diffusion in porous catalyst is taken into account. Since this model is developed in a commercial environment (ProSim Plus process simulator), particular attention is paid to the solution strategy: robustness and adaptability are of particular importance for the user. The influence of catalyst characteristic, column design, mixture non - ideality and liquid/vapour interface are discussed. We conclude that an optimum design exists. Reflux ratio and catalyst location are key-parameters.