A preliminary study on effect of additive in the removal of NOx and SO2 by electron beam irradiation

Abstract

In this study, an electron beam (EB) was used to remove target compounds (NOx and SO2), which exist in flue gas that is emitted from fossil fuel combustion. In order to improve the removal efficiency of NOx and SO2, we investigated various influencing factors such as type (H2O, NH4OH, NaCl, NaOH, Ca(OH)2, CaCl2, NaClO2, and HA–Na (C9H8Na2O4)) and injection amount of additive, and absorbed dose (5, 10, and 20 kGy). When NaOH solution was added to EB treatment process, the removal efficiencies of all target gases (NOx and SO2) were the highest. When NaOH was used as additive, the removal efficiencies of NOx and SO2 were additionally increased up to 60 and 18.5%, respectively, compared to electron beam only process. As the amount of injected additive increased, the removal efficiency also increased. The removal efficiencies of SO2, NO, and NO2 at 10 kGy were 100, 79.8, and 83.9%, respectively, when the stoichiometric ratio (reaction ratio) between target compounds and NaOH was 1:2. Also, the removal efficiencies of SO2, NO, and NO2 increased gradually as absorbed dose increased.