Mild combustion in a laboratory-scale apparatus

Mild oxidation is one of the promising techniques proposed to control pollutant emissions from combustion plants. It is characterized by high preheating of combustion air and massive recycle of burned gases before reaction. These requisites lead to high combustion efficiency and good control of thermal peaks and hot spots, lowering NO x thermal emissions. In this work, a laboratory-scale burner for mild combustion, which is an apparatus characterized by high internal recycle ratio, high back-mixing, and thepossibility of also simulating external recycles of burned gases, is described, as well as the main experimental results achieved. These were carried out to demonstrate the possibility of reproducing the main phenomena observed in real-size flameless burners. Operating conditions for obtaining stable "mild" combustion with methane and ethane as fuels were investigated and operating parameters maps were obtained.