Reactor beds are generally investigated using simplified methods, the reason being restrictions in resolving the reactor bed geometry. Such methods require empirical data, which essentially restrict the generality and reliability of the predictions. In an attempt to investigate the flow conditions in fixed reactor beds, the geometry was resolved successfully. A digitalization method was used to import the 3-D geometric information into the Computational Fluid Dynamics (CFD) code, generating a computational grid and analyzing the fluid flow regime, heat transfer and chemical reactions taking place. The current simulations are capable of predicting an overall heat transfer coefficient within 10% of the experimental value. The digitalization of a probe, however, is very restrictive. It is hence desired to enable a more generic method to describe the fixed reactor bed. First, tests were conducted to interface PFC3D with our CFD model. The results of these investigations are presented here showing that simulating the particle distribution using PFC3D is a very reliable and accurate method.