Performance and mechanism of NO reduction by iron combined with propene

NO reduction by propene with iron was experimentally studied. NO reduction efficiency at different conditions was tested in a flow-type ceramic tube reactor at 300-1100℃. The effect of SO₂ was also investigated. XRD, SEM and EDS techniques were used to analyze the composition and surface microstructure of the iron sample after reaction. Results showed that propene was effective to reduce NO with iron. More than 95% of NO was reduced above 800℃ in N₂ atmosphere and more than 90% of NO was reduced above 900℃ at fuel-rich conditions in simulated flue gas atmosphere by propene with iron respectively. SO₂ had minor effect on NO reduction. The analysis on reaction mechanism showed that when propene was used to reduce NO with iron, on one hand, NO was directly reduced by iron while propene reduced the iron oxides to iron; on the other hand, propene reduced NO via reburning reaction while the re-burning intermediates were oxidized by iron.