Advanced oxidation removal of NO and SO2 from flue gas by using ultraviolet/H2O2/NaOH process

Abstract

In this article, the effects of several process parameters (energy density per unit solution, H2O2 concentration, NaOH concentration, gas flow, solution temperature, NO concentration, O2 concentration, SO2 concentration, Fe2+ concentration and t-butanol concentration) on removal of NO from flue gas by UV (Ultraviolet)/H2O2 advanced oxidation combining with NaOH absorption (UV/H2O2/NaOH process) were investigated in a photochemical reactor. The results indicate that under all experimental conditions, SO2 can be removed completely. Increasing H2O2 concentration, NaOH concentration, energy density per unit solution, t-butanol concentration and low concentration of Fe2+ have a significant role in promoting removal of NO. NO removal efficiency sharply reduces with the increase of gas flow, NO concentration and high concentration of Fe2+. NO removal is slightly inhibited by increasing solution temperature and SO2 concentration, but is slightly enhanced by increasing O2 concentration. Oxidation of NO by OH free radicals plays an important role in the removal of NO by UV/H2O2/NaOH process. NO3− is the final reaction product of NO removal by UV/H2O2/NaOH process. The reaction mechanism of NO removal by UV/H2O2/NaOH process has also been proposed.