Assessing performance of methane tri-reforming reactor using a parametric study on the fundamental process variables

This study represents a numerical investigation of the methane tri-reforming with full computational fluid dynamics and reaction mechanisms in an adiabatic fixed-bed reactor. A 2-D axisymmetric model over nickel-based catalysts is stablished to analyze the influence of relevant parameters. The attained results revealed that the feed composition, feed flow rate, inlet temperature, operating pressure and reactor geometry have important effects on the efficiency of the reactor. The observed temperature profile proves that the temperature peak increase with the inlet temperature. Moreover, the H₂/CO ratio increases with decrement of O₂/CH₄ and CO₂/CH₄ and increment of H₂O/CH₄. As the feed flow rate rises, the CH₄ conversion, CO₂ conversion and the syngas ratio reduce. One of the most attractive results is the correlation between the pressure and the reactor performance. When the pressure falls, whereas less O₂ is consumed, the CH₄ and CO₂ conversion rise due to the increase of the initial reaction rates. Finally, it is proved that the variations of the reactor diameter have a greater impact on the reactor performance compering with the reactor length.