Optimization of NO oxidation by H2O2 thermal decomposition at moderate temperatures

H 2 O 2 was adopted to oxidize NO in simulated flue gas at 100–500°C. The effects of the H 2 O 2 evaporation conditions, gas temperature, initial NO concentration, H 2 O 2 concentration, and H 2 O 2 :NO molar ratio on the oxidation efficiency of NO were investigated. The reason for the narrow NO oxidation temperature range near 500°C was determined. The NO oxidation products were analyzed. The removal of NO x using NaOH solution at a moderate oxidation ratio was studied. It was proven that rapid evaporation of the H 2 O 2 solution was critical to increase the NO oxidation efficiency and broaden the oxidation temperature range. the NO oxidation efficiency was above 50% at 300–500°C by contacting the outlet of the syringe needle and the stainless-steel gas pipe together to spread H 2 O 2 solution into a thin film on the surface of the stainless-steel gas pipe, which greatly accelerated the evaporation of H 2 O 2 . The NO oxidation efficiency and the NO oxidation rate increased with increasing initial NO concentration. This method was more effective for the oxidation of NO at high concentrations. H 2 O 2 solution with a concentration higher than 15% was more efficient in oxidizing NO. High temperatures decreased the influence of the H 2 O 2 concentration on the NO oxidation efficiency. The oxidation efficiency of NO increased with an increase in the H 2 O 2 :NO molar ratio, but the ratio of H 2 O 2 to oxidized NO decreased. Over 80% of the NO oxidation product was NO 2 , which indicated that the oxidation ratio of NO did not need to be very high. An 86.7% NO removal efficiency was obtained at an oxidation ratio of only 53.8% when combined with alkali absorption.