OXIDATION OF NO TO NO2 BY HYDROGEN-PEROXIDE AND ITS MIXTURES WITH METHANOL IN NATURAL-GAS AND COAL COMBUSTION GASES

The CombiNO(x) process includes a family of NOx control technologies ( reburning, urea injection, methanol injection, and wet scrubbing) capa ble of reducing NOx emissions from stationary combustion sources by ab out 90%. However, methanol forms CO in flue gas as a byproduct Hydroge n peroxide and H2O2/CH3OH mixtures decrease the amount of CO formed fr om CH3OH and can substitute methanol in the CombiNO(x) process. This p aper presents experimental and modeling results on H2O2 and H2O2/CH3OH reactions with NO in a 300 kW combustor firing natural gas and coal. Maximum NO oxidation was achieved at 750-820 K for injection of H2O2 a nd 1:1 H2O2/CH3OH mixture, and at 850-930 K for CH3OH injection. NO-to -NO2 conversion of 90-98% and 64-76% was achieved at an additive NO mo lar ratio of 1.5 during natural gas and coal firing, respectively. Inf luence of initial NO concentrations, the additive/NO ratio, oxygen and SO2 concentrations, and the presence of fly ash on process performanc e is discussed. Experimental results are qualitatively explained by ki netic modeling.