TY - JOUR
T1 - On the chemical kinetics of n-Butanol
T2 - Ignition and speciation studies
AU - Karwat, Darshan M.A.
AU - Wagnon, Scott W.
AU - Teini, Paul D.
AU - Wooldridge, Margaret S.
PY - 2011/5/19
Y1 - 2011/5/19
N2 - Direct measurements of intermediates of ignition are challenging experimental objectives, yet such measurements are critical for understanding fuel decomposition and oxidation pathways. This work presents experimental results, obtained using the University of Michigan Rapid Compression Facility, of ignition delay times and intermediates formed during the ignition of n-butanol. Ignition delay times for stoichiometric n-butanol/O2 mixtures with an inert/O2 ratio of 5.64 were measured over a temperature range of 920-1040 K and a pressure range of 2.86-3.35 atm and were compared to those predicted by the recent reaction mechanism developed by Black et al. (Combust. Flame2010, 157, 363-373). There is excellent agreement between the experimental results and model predictions for ignition delay time, within 20% over the entire temperature range tested. Further, high-speed gas sampling and gas chromatography techniques were used to acquire and analyze gas samples of intermediate species during the ignition delay of stoichiometric n-butanol/O2 (χ(n-but) = 0.025, χ(O2) = 0.147, χ(N2) = 0.541, χ(Ar) = 0.288) mixtures at P = 3.25 atm and T = 975 K. Quantitative measurements of mole fraction time histories of methane, carbon monoxide, ethene, propene, acetaldehyde, n-butyraldehyde, 1-butene and n-butanol were compared with model predictions using the Black et al. mechanism. In general, the predicted trends for species concentrations are consistent with measurements. Sensitivity analyses and rate of production analyses were used to identify reactions important for predicting ignition delay time and the intermediate species time histories. Modifications to the mechanism by Black et al. were explored based on recent contributions to the literature on the rate constant for the key reaction, n-butanol+OH. The results improve the model agreement with some species; however, the comparison also indicates some reaction pathways, particularly those important to ethene formation and removal, are not well captured.
AB - Direct measurements of intermediates of ignition are challenging experimental objectives, yet such measurements are critical for understanding fuel decomposition and oxidation pathways. This work presents experimental results, obtained using the University of Michigan Rapid Compression Facility, of ignition delay times and intermediates formed during the ignition of n-butanol. Ignition delay times for stoichiometric n-butanol/O2 mixtures with an inert/O2 ratio of 5.64 were measured over a temperature range of 920-1040 K and a pressure range of 2.86-3.35 atm and were compared to those predicted by the recent reaction mechanism developed by Black et al. (Combust. Flame2010, 157, 363-373). There is excellent agreement between the experimental results and model predictions for ignition delay time, within 20% over the entire temperature range tested. Further, high-speed gas sampling and gas chromatography techniques were used to acquire and analyze gas samples of intermediate species during the ignition delay of stoichiometric n-butanol/O2 (χ(n-but) = 0.025, χ(O2) = 0.147, χ(N2) = 0.541, χ(Ar) = 0.288) mixtures at P = 3.25 atm and T = 975 K. Quantitative measurements of mole fraction time histories of methane, carbon monoxide, ethene, propene, acetaldehyde, n-butyraldehyde, 1-butene and n-butanol were compared with model predictions using the Black et al. mechanism. In general, the predicted trends for species concentrations are consistent with measurements. Sensitivity analyses and rate of production analyses were used to identify reactions important for predicting ignition delay time and the intermediate species time histories. Modifications to the mechanism by Black et al. were explored based on recent contributions to the literature on the rate constant for the key reaction, n-butanol+OH. The results improve the model agreement with some species; however, the comparison also indicates some reaction pathways, particularly those important to ethene formation and removal, are not well captured.
UR - http://www.scopus.com/inward/record.url?scp=79956082307&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79956082307&partnerID=8YFLogxK
U2 - 10.1021/jp200905n
DO - 10.1021/jp200905n
M3 - Article
C2 - 21513318
AN - SCOPUS:79956082307
SN - 1089-5639
VL - 115
SP - 4909
EP - 4921
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
IS - 19
ER -