An experimental and kinetic modeling study on nitric oxide formation in premixed C3 alcohols flames

This study provides new quantitative NO concentrations measurements in n-propanol + air and i-propanol + air flames together with a new combustion kinetic model. The heat flux method was employed to stabilize propyl alcohols flames and the initial gas conditions were set to 323 K, 1 atm, and 0= 0.7-1.4. Saturated laser-induced fluorescence was employed to measure NO concentration in the post-combustion re-gion. The presented and literature models, namely the POLIMI and Bohon et al. (2018) kinetic mechanisms, were assessed against new experimental data. Experimental results showed a higher NO formation in the thermal zone for n-propanol flames, whereas i-propanol flames indicate a higher amount of NO formed at fuel-rich conditions. Overall among the tested models, the present mechanism exhibited the best agreement in emulating NO experimental profiles; conversely, numerical simulations from the POLIMI model showed significant inconsistencies at fuel-rich conditions and the Bohon et al. (2018) model was unable to reproduce the measured data, notably underpredicting experimental values at all investigated conditions. However, the present model manifested some uncertainties in reproducing NO formation in the prompt region; therefore, in connection with this important aspect, the new experimental data obtained in this work will provide a valid support to further develop more reliable kinetic models. (c) 2020 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

Automated summary

This study presents new quantitative measurements of NO concentrations in n-propanol and i-propanol flames, along with a new combustion kinetic model. Experimental results show different NO formation characteristics between the two types of flames. The present mechanism exhibits the best agreement in emulating NO experimental profiles, with some uncertainties in reproducing NO formation in the prompt region.