Formation and destruction of nitrogen oxides in coal combustion. [Reburning]

The study of stoichiometric constraints under equilibrium conditions provides us with the following information related to reburning as a NO reduction technology: (1) The stoichiometry of air to fuel is the most important stoichiometry of air to fuel is the most important stoichiometric variable for reburning; (2) based on equivalent energy production, the comparative reduction efficiencies of the reburning fuels follow the trend: methane > ethane, ammonia > butane > aromatics, coal > CO; (3) the nitrogen in burning coals causes increases in equilibrium NO; (4) equilibrium TFN is not very sensitive in inlet NO concentration; (5) the heat carried by the flue gas in reburning could push the NO reduction toward equilibrium. If so, reburning has a strong correlation with air staging with air preheat. Further experimental verification is required.