Chemical effect of hydrogen peroxide addition on characteristics of methane–air combustion

• Effects of H2O2 on reaction pathway of methane flames are numerically investigated.
• Laminar burning velocity and flame temperature are increased with H2O2 addition.
• Reaction rates and concentrations of intermediate species are also increased.
• The reaction pathways are altered due to the enhanced production of OH and HO2.

The effects of hydrogen peroxide addition on the reaction pathway of premixed methane/air flames are numerically investigated using the PREMIX code with the GRI-Mech 3.0 chemical kinetic mechanisms and detailed transport properties. Hydrogen peroxide is used as the oxidizer substituent of air. Results show that the laminar burning velocity and adiabatic flame temperature of premixed methane–air flame are significantly increased with H2O2 addition. The addition of hydrogen peroxide increases not only all the reaction rates of intermediate species, but also the concentrations of intermediate species. The traditional reaction pathways of CH4/air flame are altered by the addition of hydrogen peroxide, due to the enhanced production of OH and HO2. The enhanced OH radicals promote HO2 productions through reaction (R89). The increased HO2 accelerates the progressive reaction of CH3 to form CH3O and then CH2O.