Effect of ethanol addition in gasoline on soot formation characteristics in diffusion flames

A novel liquid fuel combustion apparatus that can produce stable laminar diffusion flames was designed and set up. Gasoline-ethanol blends of 0%, 20%, 50% and 85% of ethanol in volume were used as fuel. Soot concentration profiles under atmospheric pressure were measured with an optical diagnostic technique to examine how adding ethanol to gasoline affects soot formation. The test results show that these gasoline-ethanol blends can generate stable diffusion flames with visible heights remaining at(50± 1) mm with increased amount of ethanol in gasoline under the condition of a fixed carbon flow rate of 6.05 g/h, that soot concentrations at different heights are reduced to different degrees, and that the total soot decreases almost linearly. The totals of soot in the flames fuelled by blends of 20%, 50%, and 85% ethanol are reduced by 16.20%, 37.77% and 61.66% respectively against that in the gasoline flame.