An experimental and modeling study of the addition of acetone to H2/O2/Ar flames at low pressure

The addition of acetone to stoichiometric and rich hydrogen/oxygen/argon flames has been investigated by measuring the intermediate species concentrations. Two premixed acetone/hydrogen/oxygen/argon flames were stabilized at low pressure (27 mbar) on a Spalding-Botha type burner at two equivalence ratios, ϕ = 1.1 and 1.72. Identification and monitoring of signal intensity profiles of species within the flames were carried out using molecular beam mass spectrometry. The detected species throughout the flame thickness are CH3COCH3 (acetone), H2, O2, Ar, H, OH, CO, CO2, H2O, HO2, CH3, CH4, CH2O (formaldehyde), CH3CO (acetyl radical), C2H2 (acetylene) and C2H4 (ethylene). The mechanism from the Université catholique de Louvain (UCL) has been extended to acetone kinetics, and has been assessed for these flames with a particular attention to the effect of the equivalence ratio on the intermediate species concentrations. Using this model, we established the main acetone degradation pathway in both flames at low pressure: CH3COCH3 → CH3COCH2 → CH2CO → CH3 → CH2O → HCO → CO → CO2