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High‐temperature ignition of propane with MTBE as an additive: Shock tube experiments and modeling
Author(s) -
Gray Jeffrey A.,
Westbrook Charles K.
Publication year - 1994
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/kin.550260710
Subject(s) - chemistry , propane , arrhenius equation , shock tube , ignition system , hydrocarbon , thermodynamics , organic chemistry , activation energy , shock wave , physics
Abstract Ignition of propane has been studied in a shock tube and by computational modeling to determine the effect of methyl tert‐butyl ether (MTBE) as a fuel additive. MTBE and isobutene were added in amounts up to 25% of the fuel to propane‐oxygen‐argon mixtures in shock tube experiments covering a range of temperatures between 1450 and 1800 K. Ignition delays were measured from chemiluminescence at 432 nm due to excited CH radicals. The temperature dependence of the ignition rates was analyzed to yield Arrhenius parameters of E a ca. 40 kcal/mol and A ca. 10 9 s −1 for the overall propane reaction and E a ca. 34 kcal/mol and A ca. 10 8.3 s −1 for the overall propane/MTBE reaction. Reactions involving MTBE and its decomposition products were combined with an established propane mechanism in a numerical model to describe the kinetic interaction of this additive with a typical hydrocarbon fuel. The experiments and the kinetic model both show that MTBE and isobutene retard propane ignition with nearly equal efficiency. The kinetic model demonstrates that isobutene kinetics are responsible for inhibition by both MTBE and isobutene, and the specific elementary reactions that produce this behavior are identified. © 1994 John Wiley & Sons, Inc.