The Effect of the Flue Gas Recirculation on NOX Formation in a Premixed Methane/Air Flam

The reaction of thermal NOX is highly sensitive to temperature and if the technique can reduce the flame temperature it would be effective to reduce NOX formation. Flue gas recirculation can reduce the flame temperature and as a result decrease the rate of NOX formation. In the present study the effect of FGR on NOX emission in the premixed methane-air mixture is investigated numerically and experimentally. The experiments arecarried out in an axial symmetry cylindrical combustion chamber for a range of equivalence ratio and different percent of FGR. The numerical simulations are conductedsimultaneously, using Premix code of Chemkin package. The GRI-Mech3.0 mechanism is used for the combustion of methane. The results reveal that as the percentage of flue gases is increased, the flame temperature and NOX are decreased. This is because of the presence of species with high thermal capacity in flue gases. The experimental results show that the NOX emission is decreased by 66 percent by addition of 30 percent of the flue gases. The simulation results are in good agreement with the experimental results

Keywords:

Flue Gas Recirculation , NOx , Methane , Air Flam