Study of the effect of methanol on the fuel-rich premixed laminar flame of n-heptane

An experimental study of the fuel-rich low pressure premixed laminar n-heptane/methanol/oxygen/argon flame was performed with the tunable synchrotron vacuum ultra-violet (VUV) pho-toionization and mass spectrometry. A literature n-heptane flame was adopted in the comparative study of the species include benzene and its precursors. The results show that, the addition of methanol can promote the combustion process, the maximum mole fraction of most of species is decreased, and the mole fraction profiles shift toward the burner surface. However, as the dehy-drogenation and dissociation reactions go further, the species in the down stream of reaction path are less affected by methanol addition. The C ₄ precursors of benzene are more sensitive to the addition of methanol compared with the C ₃ precursors. Finally, the rate of production (ROP) analysis shows that the formation path of benzene is attributed to be C ₄+C ₂ rather than C ₃+C ₃ in these flames.