Correlation of NOx Emissions with Flame Temperature in Biodiesel Combustion

This paper presents an algorithm which correlates nitrogen oxides emitted and the combustion flame temperature during the combustion of biodiesel. An iterative process is used to determine the flame temperature taking into account the phenomenon of dissociation. The results of the algorithm are presented for different blends and air-to-fuel ratios. These predicted results are compared with laboratory tests conducted in the present study on a stationary diesel engine run on different blends of biodiesel. Within the range of tests carried out, the NOx emissions from biodiesel and its blends proved to be higher than those of petro-diesel fuel. Furthermore, in this study a strong orrelation was found relating the NOx emissions and the flame temperature.