Kinetics, experimental and reactor modeling studies of the carbon dioxide reforming of methane (CDRM) over a new Ni/CeO2-ZrO2 catalyst in a packed bed tubular reactor

Kinetic, experimental, modeling and simulation studies of the carbon dioxide reforming of methane (CDRM) were performed in a catalytic packed bed reactor over a new Ni/CeO2-ZrO2 catalyst. Reactor modeling was performed using a comprehensive numerical model consisting of two-dimensional coupled material and energy balance equations. The kinetic model that best predicted the experimental rates was developed based on the Eley-Rideal (ER) formulation, assuming the methane dissociative adsorption as the rate-determining step. The best mechanistic kinetic model developed was incorporated in the reactor model which contained the axial dispersion term, and solved using the finite elements method. The validity of the reactor model was tested against the experimental data and a satisfactory agreement between the model prediction and measured results was obtained. In addition, the predicted concentration and temperature profiles for our process in the radial direction indicate that the assumption of plug flow isothermal behavior is justified within certain kinetic operating conditions. However, even when the well known criteria for neglecting the axial dispersion term have been met, there are differences in the values of conversion obtained with and without axial dispersion term. (c) 2007 Elsevier Ltd. All rights reserved.