Study on the influence of ethanol and butanol addition on soot formation in iso-octane flames

The emphasis of the work was to study the influence of ethanol and n-butanol addition on soot formation in the combustion process of iso-octane. Soot particle size distribution functions were measured at different heights above the burner in selected fuel-rich atmospheric pressure laminar premixed iso-octane/ethanol and iso-octane/n-butanol flames. The results showed that the addition of both alkanols to the reference fuel iso-octane reduces the soot formation potential in the flames. The comparison of the particle size distribution functions indicated that both the process of soot particle nucleation in the lower heights of the flame and coagulation in the larger heights of the flame are influenced by the positive effect of the addition of the oxygenated fuels. When comparing the influence of ethanol and n-butanol, it is obvious that n-butanol addition leads to a higher reduction of soot formation in iso-octane flames.