Selective non-catalytic reduction (SNCR) denitration efficiency is lower than the minimum designed requirement when the boiler is operating under low load. To improve the characteristics of such working conditions

the feature of selective non-catalytic reduction denitration with methylamine as reductants is studied and the reaction mechanism is analyzed in the tube furnace reaction system. The effect of oxygen content

NSR

initial concentration of NO

SO2 and water content on the denitrification properties of methylamine SNCR is discussed. The results show that:the relationship between denitration efficiency and temperature is bimodal

the inflection point temperature is 750℃

and the best temperature window for practical industrial application is 450-600℃. The NO reduction efficiency was increased with the increase of NSR

and the concentration of NO2 and N2O was also augmented. The maximum NO removal efficiency was 85.0%. The oxygen content has dual characteristics to SNCR denitrification reaction

the efficiency of NO reduction is the greatest under the condition of 3% oxygen content. The increase of the initial concentration of NO makes the material concentration of the simulated flue gas increase

the NO reduction efficiency and the by-product increase. The higher concentration of SO2

the greater the reduction of NO reduction efficiency. The increase of water content was beneficial to the denitrification reaction. The experimental conclusion of methylamine SNCR denitrification in this paper is helpful to the application of selective non-catalytic reduction process with methylamine as reducing agent to industrial furnace and to optimize the denitrification characteristics of the boiler at low load operation.