Simultaneous Removal of SO 2 and NO from Flue Gas Using “Oxygen-Enriched” Highly Reactive Absorbent

Fly ash, industry-grade lime, and a additive, MnO₂ (M), were used to prepare an “oxygen-enriched” highly reactive absorbent. Experiments of simultaneous desulfurization and denitrification were carried in a flue gas circulating fluidized bed (CFB). The effects of influencing factors were also investigated on the removal efficiencies of desulfurization and denitrification. Removal efficiencies of 95.5% for SO₂ and 64.8% for NO were obtained respectively under the optimal experimental conditions. The component of the spent absorbent was analyzed with chemical analysis methods. The results indicated that more nitrogen species appeared in the spent absorbent except sulfur species. A scanning electron microscope (SEM) and an accessory X-ray energy spectrometer (EDS) were used to observe microproperties of the samples, including fly ash, oxidizing highly reactive absorbent, and spent absorbent. The simultaneous removal mechanism of SO₂ and NO based on this absorbent was proposed according to the experimental results.