Effect of potassium hydroxide on PAH formation during toluene incineration

A laboratory-scale liquid-injection incinerator was used to incinerate toluene at 750°C and PAH emission was analyzed. The results indicate that the emission of solid-phase PAHs considerably increased when potassium hydroxide was added into a fuel-lean toluene flame; more potassium hydroxide resulted in more solid-phase PAHs. But this phenomenon was not observed for the fuel-rich toluene flame. The enhanced PAH formation is proposed as by-product of the partial oxidation or incomplete burning of soot in the secondary flame zone of the fuel-lean flame. It is suggested that reducing soot formation via potassium hydroxide addition may increase PAHs.