Autothermal reforming of n-hexadecane over Rh catalyst to produce syngas in microchannel reactor using finite element method

Numerical study on the autothermal reforming of n-hexadecane, which can be used in proton exchange membrane fuel cell for automotive applications, in microchannels is necessary. A 2D computational fluid dynamics (CFD) model, with combustion and reforming channels thermally coupled and separated by a metal medium wall, is developed and studied in terms of hydrogen production and catalyst activity. Rh supported on CeO2 is used as a catalyst and applied to the inner surface of the channels, where the catalytic endothermic and exothermic reactions occur. CFD analysis shows considerable results in terms of reactor performance. Along the reactor channel length, the mole percentage of hydrogen is 86% after over 2 hours of catalyst activity. The corresponding fuel conversion in respective channels is 85% on the catalytic surface of the reactor. The predicted hydrogen production from the CFD model is 59% higher than that as equilibrium conditions. Heat conduction through the medium solid wall depends on the thermal conductivity of a material. In this model, a metal solid wall with thermal conductivity of 40 W/m K, which transfers heat from the combustion channel within milliseconds, is used. The calculated model operating temperature in the reforming channel ranges from 660 to 850 K.