Microkinetic and sensitivity analysis of oxidative dry reforming of methane on Ni-Co catalyst using a reaction mechanism based on Ni

Microkinetic modelling of dry reforming of methane (DRM) with O-2 co-feed was performed using a previously developed reforming mechanism. The model was validated by comparing simulated results with experimentally determined data over a variety of reaction conditions. Numerically predicted results show that co-feeding O-2 improved CH4 conversion, reduced carbon deposition, and increased H-2/CO ratio. Microkinetic analysis shows that during oxidative dry reforming of methane (ODRM), the surface coverage of empty sites tracks the CH4 conversion. Furthermore, the H-2/CO ratio is directly related to the surface H* and CO* coverages. Sensitivity analysis highlighted that CH4 dissociation is the rate-determining step for ODRM reaction, and the adsorption-desorption steps are equilibrated. We were able to obtain a reduced mechanism (35 steps) for ODRM by applying a previously suggested hierarchical chemistry reduction strategy on the full mechanism (52 steps). The apparent activation energy for CH4 consumption and orders of the reaction were also determined.

Automated summary

The microkinetic modelling of dry reforming of methane (DRM) with O-2 co-feed shows that feeding O-2 improves CH4 conversion, reduces carbon deposition, and increases H-2/CO ratio. Microkinetic analysis reveals that the surface coverage of empty sites tracks CH4 conversion, while the H-2/CO ratio is directly related to surface H* and CO* coverages. Sensitivity analysis highlights that CH4 dissociation is the rate-determining step for the ODRM reaction.