In-flame reduction of NOx in oxy-propane combustion at high inlet oxygen concentrations: the importance of soot-NOx interactions

Other conference contribution, 2014

Previous oxy-fuel combustion of propane performed at Chalmers University of Technology has shown possi-bilities for high NOx reduction during inlet oxygen concentrations above 35%. Such enhanced reduction has not been possible to acknowledge to only homogenous reburning effects. In this work it is investigated to what ex-tent this can be an effect of soot-NOx interactions. Soot formation has been studied by using an existing soot model. By comparing modeling results with recently published experimental data it is shown that the model is capable to predict soot formation during relevant conditions. In addition, a model for homogenous nitrogen chemistry has been used in the evaluation and sensitivity to key combustion parameters. The increased amount of soot found at high oxygen concentrations, together with higher reaction activity for gas phase species, known to be of importance for both NOx formation and soot production, support the theory that the high NOx reduction found at high oxygen concentration is a result of soot-NOx interactions.