Measured peak flame temperatures and flame shape in glycerol spray flames

Glycerol, the largest by-product in the biodiesel transesterification process, is currently being investigated as a potential low-BTU fuel, particularly for biodiesel producers requiring on-site process heating. In earlier works, it was observed that the combustion of pure glycerol resulted in extremely low NO_x emissions, despite having an adiabatic flame temperature that is comparable with more traditional fuels such as diesel. This work attempts to investigate the cause of this low NO_x formation through measurements of the time-averaged, spatially resolved peak flame temperatures via thermocouples. Comparisons are made with diesel fuel in the same swirl burner over a range of operating conditions and flame structures.