Catalytic and kinetic analysis of the methane tri-reforming over a Ni–Mg/β-SiC catalyst

•A higher CO2 feed volume flow not always increased the CH4 conversion.•CO2 net production was observed for certain feed compositions and temperatures.•Full oxygen conversion was observed for almost all the experiments.•The kinetic model shows a good accuracy between modelled and experimental data.

In this work, the influence of the temperature and feed composition on the catalytic behaviour of a Ni–Mg/β-SiC catalyst in the methane tri-reforming was analysed and modelized. This catalyst was characterized by Atomic Absorption Spectrophotometry (AAS), Temperature Programmed Reduction (TPR), N2 adsorption, Temperature Programmed Desortion of CO2 (TPD) and X-Ray Diffraction (XRD). 36 catalytic experiments at different temperatures and feed compositions were performed, modifying the quantity of CH4, CO2, H2O and O2 present in the feed. The predominance of each one of the reactions that took place during the tri-reforming process was evaluated as a function of the temperature, finding at low temperatures a higher contribution of both the steam reforming and the water gas shift reactions. On the contrary, at higher temperatures, a higher contribution of the dry reforming was detected. Finally, a kinetic model was raised and experimental data were fitted to it. Steam reforming, dry reforming and water gas shift reactions were considered as the kinetically relevant equations. A good agreement between experimental and predicted data was observed.