Evidence for the contribution of methane in the formation of aromatics andsoot in fuel-rich pre-mixed combustion

Experimental results from an isothermal laminar Row reactor at atmospheric pressure are presented on the chemical composition in the post-oxidative re gion of two sooting fuel-rich pre-mixed mixtures diluted in nitrogen. A bas e case composed of n-heptane and O-2 in N, at 1425 K with a C/O of 2.85 was perturbed by substituting 10%, of the carbon in n-heptane with carbon as C H4. While these changes would intuitively reduce aromatics and soot formati on by increasing H-2 and decreasing C2H2 concentrations, we observe the opp osite. The concentrations of individual aromatic species are observed to ac tually increase by up to 50% and the soot yield increases by 80%. (C) 2001 Elsevier Science Ltd. All rights reserved.