Correlation between temperature, O2, NOX and PAH concentrations in heavy oil flames

The combustion of liquid hydrocarbons is widely used for many industrial processes involving energy conversion. In such practical applications, heavy oil appears as an important fuel. The pollutant emissions from the spray combustion of heavy oil fuels must be reduced to satisfy the more and more stringent limits imposed by different governments. Different configurations of the combustion air dynamic have been proposed and the stage combustion is revealed the most widely employed. The fundamental step of this process is the formation of a rich combustion zone to reduce the temperature and to form radicals able to react with NO. In this zone it is easy to believe that also PAHs are produced. The aim of this work is to study the correlation between chemical aspects, as the pyrolysis both in the gaseous and liquid phases, and physical aspects, as the thermal and fluid dynamic behaviour of the spray and its interaction with swirled air flows. Heavy oil spray flames have been investigated in a triflux burner by measurements of light scattering, temperature and gas sampling, in order to obtain information on the effect of the different parameters affecting the pollutant emissions with particular regard to the carbonaceous particles, PAHs and NOx.