Behavior of PAHs and PM in a diffusion flame of paraffin fuels

► PAHs, soot and PM components in diffusion flames of paraffin fuels were measured. ► PAHs in the flames were measured quantitatively using a GC system. ► Position of PAH formation region in a flame depended on the carbon number of fuel. ► PM concentration in the flame increased with an increase of fuel carbon number. ► Aromatic molecules such as benzene and toluene were emitted from the flame tip.