Kinetics of Natural Gas, Natural Gas/Syngas Mixtures Oxidation and Effect of Burnt Gas Recirculation: Experimental and Detailed Modeling

The oxidation of methane-based fuels was studied experimentally in a fused silica jet-stirred reactor (JSR) operating at 1–10 atm, over the temperature range 900-1400 K, from fuel-lean to fuel-rich conditions. Similar experiments were performed in presence of carbon dioxide or syngas (CO/H₂). A previously proposed kinetic reaction mechanism updated for modeling the oxidation of hydrogen, CO, methane, methanol, formaldehyde, and natural gas over a wide range of conditions including JSR, flame, shock tube, and plug flow reactor was used. A detailed chemical kinetic modeling of the present experiments was performed yielding a good agreement between the data and the modeling. Literature burning velocities and ignition delays were also modeled. Reaction paths analyses were used to delineate the important reactions influencing the kinetic of oxidation of the fuels in presence of variable amounts of CO₂. The kinetic reaction scheme proposed helps determining the effect of the additives on the oxidation of methane.