Shock tube measurements of ignition delay times for n-decane and decenes: the influence of the double bond

Abstract

In order to understand the influence of double bond and its position on decene isomer oxidation, shock tube measurements has been performed to investigate the autoignition of n-decane, 1-decene, and 5-decene within a temperature range of 650-1300 K. Mixtures comprised of these C10 speices in air at equivalence ratios of 0.5, 1 and 1.5 were studied at an initial pressure of 20 atm. A stoichiometric case at an elevated initial pressure of 40 atm was also carried out for comparison. Although no previous study exists for direct comparison, the experimental results agree with the trends of previous studies for various alkenes and alkanes. For 5-decene, with the double bond centrally located, the ignition delay data illustrates slightly increased reactivity at higher temperatures and a significantly lower reactivity for temperatures lower than 950 K when compared to both n-decane and 1-decene. 1-Decene results show similar reactivity to n-decane at high temperatures and slightly slower reactivita at low temperatures. Chemical kinetic model predictions are compared to the shock tube results and possible reaction pathways are discussed. Only the high temperature trends for decene isomer reactivity were captured due to the limitations of models available in the literature. The results of this experimental work should serve as an important reference for understanding alkene oxidation and provide quantitative targets for the future development of kinetic models.