Influences of reaction conditions on the CH₄-CO₂ reforming and coking properties of a Ni-CaO-ZrO₂ catalyst

CH₄-CO₂ reforming was carried out over a Ni-CaO-ZrO₂ catalyst prepared by co-precipitation. The influence of reaction conditions like temperature, space velocity and feed component on CH₄-CO₂ reforming and coking properties was studied. Thermodynamic calculation as well as experimental measurement indicated that the reaction conditions play an important role in the behaviors of reforming and coke deposition. Higher activity and stability are observed under higher temperature due to the enhancement of both CH₄ decomposition and elimination of carbon species formed at such condition. At higher space velocity, both the conversion of CH₄ and the rate of carbon elimination are decreased, resulting in an increase of carbon deposition. The component of feed gases also has a significant impact on the amount of carbon deposited; a higher CO₂/CH₄ molar ratio is favored in suppressing coking during the reforming reaction.