Simultaneous absorption of SO2 and NO from flue gas by ammonia solution with a wetted-wall column

Abstract

In a self-designed wetted column, the effects of absorption concentration, initial pH, liquid-gas ratio, SO2 inlet concentration, NO inlet concentration on desulfurization and denitration efficiency were studied with ammonia solution. The results show that the removal efficiency of SO2 and NO can be improved by increasing the concentration of absorption liquid and liquid-gas ratio. The presence of SO2 can promote the removal of NO. Increasing SO2 concentration and NO concentration are not conducive to removing SO2. The liquid-phase and gas-phase mass transfer coefficients of SO2 in the system were determined. The results demonstrate that when inlet concentration of SO2 and NO is about 1100 mg/m3 and 500 mg/m3 respectively, the best technical parameters are 4 to 5 L/m3 for the liquid-gas ratio, 6.0 to 7.0 for the pH of absorption, 3%(wt) for Ammonia concentration. Under the best experimental conditions, the removal efficiency of SO2 can reach above 99%, and that of NO can reach above 50%.