Chemical Effect of CH4 on NH3 Combustion in an O2/N2 Environment Via ReaxFF

At a time of striving for CO2-free power, NH3 becomes a potential energy storage carrier fuel from renewable sources. The reaction molecular dynamics (ReaxFF-MD) method was used to study the effect of CH4 reactivity on NH3 oxidation in an O2/N2 environment. The conversion process of combustion intermediates in the combustion process is explored. Under fuel-rich, stoichiometric, and fuel-lean conditions, at a temperature of 2400–3200 K, mixed combustion of NH3 and CH4 with different concentration ratios is simulated. Studies have found that ammonia combustion and methane combustion are not competitive reactions. After adding methane, the consumption rate of ammonia will increase, but the intensity of the reaction will decrease. After adding methane, H2 is the product with the greatest impact on production. The H2O produced by the reaction will also participate in the subsequent reaction. Under different O2 concentrations, the quantitative changes before and after the reaction can be concretely reflected by ReaxFF simulation, which lays the foundation for subsequent research.