Study on the Oxidation Characteristics and Kinetics of Ammonia Blended With Synthetic Flue Gas

Ammonia (NH ₃ ), a hydrogen‐rich, zero‐carbon fuel, faces low reactivity and high NO _x emissions in industrial applications. This study investigates co‐oxidation of NH ₃ with synthetic flue gas comprising N ₂ , H ₂ O, and NO through experiments and numerical simulations, focusing on preheating, inert atmosphere regulation, and humidification. A kinetic model is developed and optimized using measured species profiles. NH ₃ oxidation experiments were conducted on mixtures of NH ₃ and synthetic flue gas using the present experimental platform. The operating conditions included equivalence ratios of 0.1–1.5, NH ₃ blending ratios of 10%–30%, residence times of 1–2 s, and temperatures of 800–1400 K. The optimized mechanism reproduces the experimental trends. Blending 30% synthetic flue gas reduces the onset temperature of NH ₃ oxidation by 125 K and the residual NH ₃ concentration by 62.9%; NO _x concentrations decrease with increasing equivalence ratio and residence time. Reaction pathway analysis indicates that synthetic flue gas does not change the dominant NO formation routes but enhances NH ₃  → NH ₂  → NH → HNO → NO, revealing how individual flue‐gas components modulate key intermediates and NO _x formation and consumption.