A wide-range experimental and kinetic modeling study of the pyrolysis and oxidation of 2-butyne

To reduce particulate emissions leading to a cleaner environment, it is important to understand how polycyclic-aromatic hydrocarbons (PAHs) and their precursors are formed during combustion. 2-butyne can decompose to propargyl and allyl radicals. These radicals can produce benzene and other PAHs, leading to the formation of soot. In the present study, pyrolysis, oxidation, and laminar flame speed experiments were performed for 2-butyne. The pyrolysis experiments were conducted in a single-pulse shock tube at 2 bar in the temperature range 1000 - 1500 K. Ignition delay times for 2-butyne/'air' mixtures were measured in the pressures range 1 - 50 bar, over the temperature range 660 - 1630 K, at equivalence ratios of 0.5, 1.0, and 2.0 using rapid compression machines and shock tubes. Moreover, laminar flame speed (LFS) experiments were performed at ambient temperature, at p = 1 - 3 atm, over an equivalence ratio range of 0.6 - 1.8. A new, detailed chemical kinetic model for 2-butyne has been developed and widely validated against the datameasured in this study and those available in the literature. The significant reactions for 2-butyne pyrolysis, ignition, and oxidation are identified and discussed using flux and sensitivity analyses.& COPY; 2022 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

Automated summary

In order to reduce particulate emissions and improve air quality, it is crucial to understand the formation of polycyclic-aromatic hydrocarbons (PAHs) and their precursors during combustion, particularly for 2-butyne. This study conducted pyrolysis, oxidation, and laminar flame speed experiments for 2-butyne, and developed a comprehensive chemical kinetic model that was validated against experimental data. The research findings identify the key reactions involved in 2-butyne decomposition, ignition, and oxidation, shedding light on the formation mechanisms of PAHs and offering insights for reducing soot emissions.