A simulation of the fluid dynamic based on an Euler approach ignores the discreet structure of the liquid current in trickle bed reactors in the so-called poor interaction regime. Therefore, a discreet model for the trickle flow which is based on a detailed knowledge of the complicated pore geometry of the fixed bed should be developed within the scope of this research project. With the knowledge of the liquid distribution and the reaction kinetics a discreet reactor model can be developed from a three-dimensional interconnection of continuously pursued ideal reactors to the reaction-technical design of catalytic trickle bed reactors. The efficiency of the so preserved model is to be proved by comparison with experiments for every single developing step.