CFD Analysis of the Channel Shape Effect in Monolith Catalysts for the CH sub(4) Partial Oxidation on Rh

Catalysts monoliths with circular and square ducts are theoretically analyzed in detail as reactor configurations for the adiabatic CH sub(4) partial oxidation on Rh for short-contact-times hydrogen production. By the means of CFD coupled with a detailed microkinetic description of the surface reactivity, it was found that the different transport properties of the investigated configurations primarily affect the thermal behavior of the reactor. O sub(2) consumption is fully external mass transfer limited, and thus, local variations in mass transport properties are responsible of the differences in surface temperature. First-principles-based multiscale modeling of heterogeneous catalysis is one of the most challenging and emerging topics in catalytic reaction engineering. A rigorous multiscale analysis on how the reactor geometry affects the performances of reactors with honeycomb structure is proposed, coupling CFD simulations with microkinetic modeling.