CFD simulation of a turbulent oxy-fuel flame

The problem of pollutant emissions from combustion devices is moving the attention towards the development of new combustion technologies. In this context, oxy-fuel combustion, in which the fuel is fed with an oxygen-enriched gas mixture instead of air, represents a promising solution. Two of the most important advantages are represented by the reduction of nitrogen oxide (NOX) formation and the ability to capture CO2 from power plants and, more generally, to control the corresponding emissions. The reduction of N2 content during combustion makes easier the CO2 capture for its successive storage. Additional advantages can be clearly identified in terms of higher temperature, higher flame speed and stability. In this work numerical simulations of a semi-industrial furnace, fed with natural gas and pure oxygen, both containing N2 in traces, are presented and discussed. The combustion chemistry is described through a detailed mechanism and the Eddy Dissipation Concept (EDC) model is adopted for the description of chemistry-turbulence interactions. The attention is devoted to the estimation of NOX formation in the furnace by the application of a newly conceived kinetic post-processor, able to manage very large kinetic schemes.