화학공학소재연구정보센터
Energy & Fuels, Vol.31, No.3, 3047-3054, 2017
New Experimental Results of NO Removal from Simulated Flue Gas by Wet Scrubbing Using NaClO Solution
Both cyclic and noncyclic scrubbing experiments were conducted to remove NO from simulated flue gas in a lab scale countercurrent spraying reactor. The effects of various operating parameters (initial solution pH, NaClO concentration, absorbent temperature, and inlet NO and SO2 concentrations) on NO removal efficiencies were investigated in the noncyclic scrubbing mode. The results showed that NO removal efficiency increased greatly with the decrease of the initial pH value. However, there was a drop in NO removal efficiency, possibly due to the NO2 absorption in the gas phase. NO removal efficiency increased gradually with the increase of the NaClO concentration. Complete removal of NO was achieved when the NaClO concentration was 24 X 10(-3) mol.L-1. However, the NO removal efficiency obviously decreased with the absorbent temperature increasing from 303 to 343 K. This could be mainly ascribed to the decrease of the water solubility of NO2 and the absorption reaction of NO2 with water vapor. Furthermore, NO removal efficiency increased quickly with the increase of the inlet NO concentration. The coexisting SO2 in the simulated flue gas had little effect on the NO removal efficiency. Both NO and SO2 could be removed simultaneously with a SO2 removal efficiency of 100% and a NO removal efficiency of >93%. More importantly, the results of cyclic scrubbing experiments indicated that an average NO removal efficiency of 74% had been obtained for the whole cyclic scrubbing duration. The utilization of NaClO oxidant was calculated to be approximately 83%. The ion chromatographic analysis showed that there was no ON2- in the spent liquor. The results demonstrate that NaClO is a low-cost high-efficiency oxidant for NO removal from exhaust gas and that it has great potential for industrial applications.