TY - JOUR
T1 - Low-temperature speciation and chemical kinetic studies of n-heptane
AU - Karwat, Darshan M.A.
AU - Wagnon, Scott W.
AU - Wooldridge, Margaret S.
AU - Westbrook, Charles K.
N1 - Funding Information:
The authors would like to thank the US Department of Energy Basic Energy Sciences, the US Department of Energy via the University of Michigan Consortium on Efficient and Clean High-Pressure, Lean Burn (HPLB) Engines, the Michigan Memorial Phoenix Energy Institute and the Graham Environmental Sustainability Institute for their financial support. The computational portion of this work was supported by the US Department of Energy, Office of Vehicle Technologies and the Office of Basic Energy Sciences and was performed under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. The authors would like to thank Dr. Stephanie Villano and Professor Anthony Dean of the Colorado School of Mines and Dr. William Pitz and Dr. Marco Mehl from LLNL for their insights into low-temperature chemistry. We would also like to thank Dr. Henry Curran, Dr. Darren Healy, Dr. John Griffiths, Dr. Guillaume Vanhove, and Dr. Rodolfo Minetti for sharing their experimental data.
Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2013/12
Y1 - 2013/12
N2 - Although there have been many ignition studies of n-heptane-a primary reference fuel-few studies have provided detailed insights into the low-temperature chemistry of n-heptane through direct measurements of intermediate species formed during ignition. Such measurements provide understanding of reaction pathways that form toxic air pollutants and greenhouse gas emissions while also providing key metrics essential to the development of chemical kinetic mechanisms. This paper presents new ignition and speciation data taken at high pressure (9. atm), low temperatures (660-710. K), and a dilution of inert gases-to-molecular oxygen of 5.64 (mole basis). The detailed time-histories of 17 species, including large alkenes, aldehydes, carbon monoxide, and n-heptane were quantified using gas chromatography. A detailed chemical kinetic mechanism developed previously for oxidation of n-heptane reproduced experimentally observed ignition delay times reasonably well, but predicted levels of some important intermediate chemical species that were significantly different from measured values. Results from recent theoretical studies of low temperature hydrocarbon oxidation reaction rates were used to upgrade the chemical kinetic mechanism for n-heptane, leading to much better agreement between experimental and computed intermediate species concentrations. The implications of these results to many other hydrocarbon fuel oxidation mechanisms in the literature are discussed.
AB - Although there have been many ignition studies of n-heptane-a primary reference fuel-few studies have provided detailed insights into the low-temperature chemistry of n-heptane through direct measurements of intermediate species formed during ignition. Such measurements provide understanding of reaction pathways that form toxic air pollutants and greenhouse gas emissions while also providing key metrics essential to the development of chemical kinetic mechanisms. This paper presents new ignition and speciation data taken at high pressure (9. atm), low temperatures (660-710. K), and a dilution of inert gases-to-molecular oxygen of 5.64 (mole basis). The detailed time-histories of 17 species, including large alkenes, aldehydes, carbon monoxide, and n-heptane were quantified using gas chromatography. A detailed chemical kinetic mechanism developed previously for oxidation of n-heptane reproduced experimentally observed ignition delay times reasonably well, but predicted levels of some important intermediate chemical species that were significantly different from measured values. Results from recent theoretical studies of low temperature hydrocarbon oxidation reaction rates were used to upgrade the chemical kinetic mechanism for n-heptane, leading to much better agreement between experimental and computed intermediate species concentrations. The implications of these results to many other hydrocarbon fuel oxidation mechanisms in the literature are discussed.
KW - Chemical kinetics
KW - Ignition delay
KW - N-Heptane
KW - Rapid compression facility
KW - Speciation
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U2 - 10.1016/j.combustflame.2013.06.029
DO - 10.1016/j.combustflame.2013.06.029
M3 - Article
AN - SCOPUS:84885323362
SN - 0010-2180
VL - 160
SP - 2693
EP - 2706
JO - Combustion and Flame
JF - Combustion and Flame
IS - 12
ER -