The effect of nitrogen content in oxy-natural gas combustion on the CO concentration in premixed flame

This paper shows the report results of experimental and numerical studies of the formation of CO in the kinetic natural gas flame in oxy-combustion conditions, when the completely nitrogen-free atmosphere cannot be ensured. The aim of these studies was to determine the effect of nitrogen addition to the furnace chamber on the variations in CO concentration. The addition of nitrogen to oxy-combustion reflects the sources of nitrogen in industrial furnaces, which can be: additives used to accelerate the charge melting in glass production, inadequate oxygen purity and a leaky chamber. It has been demonstrated experimentally that by adding nitrogen to an oxidizing atmosphere composed of 27 v/v % O2 and CO2, the CO concentration in the flame region was reduced. By using the program Chemked II and the detailed combustion mechanism created by Mendiara and Glarborg, an analysis of the rate of reactions having a significant effect on the CO concentration in the flame was made, and predominant reactions responsible for the formation of CO have also been listed. It was stated that both extending the combustion product residence time and increasing the nitrogen content of the combustible mixture lead to a reduction of CO concentrations in the flame.