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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-421-2

International Heat Transfer Conference 15
August, 10-15, 2014, Kyoto, Japan

Role of CO2 in the Soot Formation and Reduction Mechanisms in CH4 Flat Flame Doped with Toluene under O2/CO2 Environments

Get access (open in a dialog) DOI: 10.1615/IHTC15.cmb.009464
pages 1217-1225

Abstract

This study aims to investigate the impact of CO2 reactivity on soot reduction in O2/CO2 combustion. The measurements of unburnt hydrocarbons of CH4 and C2H2 were performed in a fuel-rich flat CH4 flame doped with toluene. CHEMKIN-PRO was used to study the interaction between CO2 reactivity and soot reduction. As a result, both calculation and experiment showed a less amount of CH4 and C2H2 from O2/CO2 combustion than those from the air combustion. Calculated PAH concentration in O2/CO2 combustion was significantly lower than that in air combustion. CO2 was not inert but participates in chemical reactions primarily through the reaction CO2 + H → CO + OH (R1) and C2H2 was a dominant mass source for PAH growth. Calculations showed that an abundant OH radicals formed by R1 inhibited C2H6 formation through CH3 recombination reaction, leading to decreasing C2H2 formation rate. This resulted in inhibiting PAH growth. It was shown that O2/CO2 environments were suited to reduce soot due to the CO2 reactivity.