The effects of Na/K additives (NaOH

Na2CO3

NaCl

KOH

K2CO3 and KCl) on NO reduction in the selective non-catalytic reduction (SNCR) process were simulated by using Chemkin software based on the established chemical mechanisms of Na-K-C-H-O-N-Cl. The mechanism and routes of Na/K additives on NO reduction in the SNCR process were discussed based on the sensitivity analysis and rate of production (ROP) analysis. The simulated results indicated that NO removal efficiency was almost zero at temperature of 700-800℃ in the SNCR process without Na/K additives. Na/K additives had a significant promotion on NO reduction at temperature lower than 800℃

and had less promotion on NO reduction at temperature higher than 900℃. At temperature of 700℃

NO removal efficiency was 43.86%-60.76% in the SNCR process with Na/K additives. The promotion order of Na/K additives on NO reduction in the SNCR process was NaOH≈Na2CO3 > KOH≈K2CO3 > KCl > NaCl. However

the concentration of Na/K additives (6.25-25.0 μmol·mol-1) showed little influence on NO reduction. NO reduction in the SNCR process was performed through NH2 radicals

which were promoted by OH radicals via respective reaction routes promoted by Na/K additives. The promotion of Na/K additives on NO reduction in the SNCR process was enhanced by alkali metal hydroxides (MOH) via the route of NaOH→NaO2→Na→NaO→NaOH

but weakened by alkali metal chlorides (MCl) via the route of MCl→M→MCl.