Ignition delay times of n-butane and i-butane under O2/CO2 atmospheres: Shock tube experiments and kinetic model

Pressurized oxy-fuel combustion is deemed an advanced oxy-fuel combustion technique due to the lower cost and little decrease in the generating efficiency compared to conventional PC system without CO 2 capture. Butane is an important composition of petroleum and natural gas. In this work, the ignition delay times (IDTs) for n-butane and i-butane under O 2 /CO 2 atmospheres were measured in a shock tube at different equivalence ratios ( 0) and pressures. Based on our previous C 1 -C 3 model Oxymech2.0 and the C 4 sub-model of Aramco3.0, a chemical kinetic model Oxymech2.0 Plus was updated. Oxymech2.0 Plus was validated by the newly measured IDTs of butane under O 2 /CO 2 atmospheres. The model was also validated by the literature experimental data for IDTs of n-butane and i-butane at O 2 /Ar and O 2 /N 2 atmospheres, laminar flame speeds of n-butane and i-butane in air, and species profiles of n-butane and i-butane pyrolysis. The comparison between Oxymech2.0 Plus and Aramco 3.0 models was also conducted in detailed. The results show that the updated reactions in the study significantly improve the prediction of IDTs, laminar flame speeds and species profiles of butane in O 2 /CO 2 atmospheres. The effects of equivalence ratios and CO 2 on the IDTs of n-butane and i-butane were analyzed. (c) 2021 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

Automated summary

Pressurized oxy-fuel combustion is considered an advanced technique with lower cost and little decrease in efficiency compared to conventional PC systems without CO2 capture. Experimental and modeling work on n-butane ignition delay times under different conditions validates the updated chemical kinetic model Oxymech2.0 Plus, which shows improved prediction accuracy for butane combustion in O2 / CO2 atmospheres. The effects of equivalence ratios and CO2 concentrations on the ignition delay times of n-butane were analyzed.