Simultaneous desulfurization and denitrification of sintering flue gas via composite absorbent

Experiments on simultaneous absorption of SO2 and NOX from sintering flue gas via a composite absorbent NaClO2/NaClO were carried out. The effects of various operating parameters such as NaClO2 concentration (m(s)), NaClO concentration (m(p)), molar ratio of NaClO2/NaClO (M), solution temperature (T-R), initial solution pH, gas flow (V-g) and inlet concentration of SO2 (CS) and NO (C-N) on the removal efficiencies of SO2 and NO were discussed. The optimal experimental conditions were determined to be initial solution pH = 6, TR = 55 degrees C and M = 1.3 under which the average efficiencies of desulfurization and denitrification could reach 99.7% and 90.8%, respectively. Moreover, according to the analysis of reaction products, it was found that adding NaClO to NaClO2 aqueous solution is favorable for the generation of ClO2 and Cl-2 which have significant effect on desulfurization and denitrification. Finally, engineering experiments were performed and obtained good results demonstrating that this method is practicable and promising. (C) 2016 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.