posted on 2015-12-17, 05:54authored byMatteo Pelucchi, Mattia Bissoli, Carlo Cavallotti, Alberto Cuoci, Tiziano Faravelli, Alessio Frassoldati, Eliseo Ranzi, Alessandro Stagni
The
low- and high-temperature oxidation mechanisms of n-heptane have been extensively studied in recent and past literature
because of its importance as a primary reference fuel. Recent advanced
analytical methods allowed for the identification of several intermediate
oxygenated species at very low-temperature conditions in jet-stirred
reactors. On these bases, new classes of successive reactions involving
hydroperoxide species, already discussed for propane and n-butane oxidation, were included in the low-temperature oxidation
mechanism of n-heptane. These new reactions allowed
for the improvement of the overall mechanism, not only obtaining a
satisfactorily agreement with reaction products, such as organic acids,
diones, and ketones, but also in terms of system reactivity. Moreover,
deeper attention was also paid to the formation of ketohydroperoxides,
rarely experimentally measured. Because of n-heptane
importance as a primary reference fuel, the overall POLIMI kinetic
mechanism is validated in a wide range of conditions, in both the
high- and low-temperature regimes. Moreover, the reliability of the
updated oxidation mechanism is further proven in a couple of more
complex applications, such as the autoignition of n-heptane droplets in microgravity conditions and the oxidation of
lean n-heptane/air mixtures in homogeneous charge
compression ignition (HCCI) engines.