Interactions of SO₂ in the no reduction process during methane reburning

Leeds mechanism was adopted to investigate the effect of SO₂ on the NO reduction during the process of methane reburning in a plug flow reactor, based on the comparison with Glarborg's results from methane reburning experiments. Results show that, when there is no SO₂ addition, computational results coincide with the experimental results, and the highest efficiency of NO reduction is obtained at the optional air excess coefficient 0.8. Further analysis with SO₂ addition shows that the optimal air excess coefficient increases from 0.8 to 0.87 with the increase of SO₂ concentration from 0 to 3000 × 10^-6. Under the oxygen-rich condition, the addition of SO₂ always enhances the reduction of NO during methane reburning. Under the fuel-rich condition, SO₂ addition inhibits the reduction of NO when the air excess coefficient is in the scale 0.65~1, however, when the air excess coefficient is less than 0.65, SO₂ addition only affects the reduction of NO trivially. The effecting mechanisms of SO₂ on NO reduction were demonstrated by the main control elementary reaction obtained from the sensitivity analysis.