Trickle bed reactors are widely used in petroleum refining industry for various hydro-treating purposes to remove sulfur primarily from light and middle distillates. In last few years due to stringent environmental norms on emission, importance of rigorous design of trickle bed reactor has drawn much research attention. Although the technology of trickle bed reactor design is well established, it has been essentially based on heuristics. With availability of more computational power, computational fluid dynamics (CFD) appears to be an essential tool to understand effect of flow on transport...