Partitioning of nitrogenous species in the fuel-rich state of reburning

The effect of reburning fuel type on the partitioning of fixed-nitrogen species in the fuel-rich stage of reburning was studied in a bench scale flow reactor. Methane, hexane, benzene, bituminous coal, and lignite were used as reburning fuels. A simulated flue gas consisting of CO 2 (16.8%), 0 2 (1.95%), NO (1000ppm), and helium was used for experiments at 1100 o C and ca. 0.2s residence time. The total fixed nitrogen (TFN) speciation was found to depend strongly on fuel type ans stoichiometric ratio (SR). Rich stoichiometries promoted conversion of NO to HCN, whereas conversion of HCN to N 2 was promoted by lean stoichiometries. In this stimulated reburning stage, the optimum stoichiometry of TFN production for gaseous fuels was ca. SR=0.95