Simultaneous Removal of SO2 and NO by Highly Reactive Absorbent Containing Calcium Hypochlorite

Fly ash, industrial lime, and an additive [calcium hypochlorite (C)] were used to prepare a highly reactive absorbent. Simultaneous desulfurization and denitrification were carried out in a flue gas circulating fluidized bed (CFB). The effects of influencing factors on the removal efficiencies of SO2 and NO were also investigated. Removal efficiencies of 94.5% for SO2 and 65.5% for NO were obtained under the optimal experimental conditions. The component of the spent absorbent was analyzed with chemical analysis methods. The results indicated that more nitrogen than sulfur species appeared in the spent absorbent. A scanning electron microscope (SEM) and an accessory X-ray energy spectrometer (EDS) were used to observe the microproperties of the samples, including fly ash, highly reactive absorbent, and spent absorbent. The removal products of spent absorbent were analyzed using ion chromatography and chemical analysis. The simultaneous removal mechanism of SO2 and NO based on this absorbent was proposed according to the experimental results. (C) 2008 American Institute of Chemical Engineers Environ Prog, 27: 460-468,2008