Abstract |
The article gives results of an experimental study of nitric oxide (NO) destruction in the fuel-bed of a coal-fired spreader stoker. NO was injected into the coal bed and freeboard flame zone under varying local stoichiometries to determine the fate of NO in the primary combustion zone. In general, a high capacity for NO reduction was observed, with bed-phase reduction contributing most significantly to the overall mechanism. Fractional survival of injected NO, as well as fuel nitrogen conversion to exhaust NO, decreased with decreasing bed-region stoichiometry. Staged firing also decreased NO survival by increasing residence time in the fuel-rich primary combustion zone. The modest nitrogen oxides (NOx) reductions achievable with Flue Gas Recirculation (FGR), a practical NOx control technique, are due in part to the more than 50% destruction of NO in the recycled flue gases. (Copyright (c) 1987 American Chemical Society.) |