Dynamics and emission of nearly flameless combustion of waste cooking oil biodiesel in an ultra-low emission non-MILD swirl burner

Abstract

The ongoing energy revolution demands a drastic change in energy carriers used, which especially stresses the industry and transportation, where combustion seems to have no generally feasible alternative. Consequently, both advanced combustion systems with ultra-low emission and high fuel flexibility are essential to mitigate the problems. The Mixture Temperature-Controlled (MTC) combustion concept can potentially fill this gap, developed by our research group. It features no exhaust gas recirculation, and the internal recirculation rate is low compared to flameless combustion chambers. It was demonstrated that the MTC burner could utilize even neat waste cooking oil biodiesel at nearly flameless combustion conditions. The resulting < 15 mg/Nm3 NOX and < 5 mg/Nm3 CO emission at 15% O2 complies with the requirements of the strictest current standards with more than a 70% margin. Microphone and photomultiplier tube measurements showed the low susceptibility to thermoacoustic instabilities. The overall sound pressure level of nearly flameless combustion was more than 8 and 10 dB lower than that of V-shaped and straight flames, and the accompanying chemiluminescent intensity level was more than 15 dB lower than that of straight flames. The potential applications of this new concept are gas turbines and boilers.