Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.
In this study, the synergistic effects of ethylene-propane and
ethylene-dimethyl ester (DME) mixtures on soot formation
were investigated experimentally using a co-flow diffusion
flame burner. The soot volume fraction, soot particle diameter,
and number density were measured and compared to the
homogenous mixture. Addition of DME and propane to the
ethylene fuel increased soot volume fraction in the ethylene
flames. The ethylene-propane has more pronounced synergistic
effect in comparison to the ethylene–DME flames. This is due
to the fact that during the decomposition of propane some
methyl radicals are generated. The reactions related to these
methyl radicals promote the formation of propargyl radicals
consequently the formation of benzene through propargyl selfreaction
and finally to the soot formation. Although DME
decomposition produces methyl, C-O bond in the DME
removes some carbon from the reaction path to form soot.
Hence the soot formation in ethylene-DME mixture is much
lower than that of ethylene-propane mixture.
