An experimental investigation of ammonia/landfill/air mixtures' pollutant emissions and temperature distribution under non-preheated moderate or intense low-oxygen dilution combustion.

This paper investigates the non-preheated MILD combustion behavior of landfill/ammonia mixtures. The experiments were carried out in a laboratory-scale furnace. The effects of equivalence ratio variation, CO dilution, and ammonia on the furnace temperature distribution and exhaust gas emissions were analyzed attentively. The experiment results indicate that a non-preheated MILD combustion establishment can provide a uniform temperature distribution and lower pollutant emissions while maintaining the same thermal efficiency. According to the results, equivalence ratio changes affect the MILD temperature structure sensibly. Variation of equivalence ratio is also effective on the pollutant emissions. Moreover, the rich burn condition increases the CO emissions by bringing the HCN and H radicals into the related reactions. Whereas in lean-burn states, little amounts of CO are generated, while the NO concentrations are higher due to the NH pathways. The results also indicate that CO dilution reduces the furnace's peak temperature. However, CO dilution may also increase the O and OH radicals, allowing HCN molecules to react and generate NO. Regarding the ammonia addition experiments, it was figured out that ammonia increases NO emissions, while decreasing CO concentrations affect the flame temperature profile.