title: An experimental and kinetic modeling study of the oxidation of the four isomers of butanol.
abstract: Butanol, an alcohol which can be produced from biomass sources, has received recent interest as an alternative to gasoline for use in spark ignition engines and as a possible blending compound with fossil diesel or biodiesel. Therefore, the autoignition of the four isomers of butanol (1-butanol, 2-butanol, iso-butanol, and tert-butanol) has been experimentally studied at high temperatures in a shock tube, and a kinetic mechanism for description of their high-temperature oxidation has been developed. Ignition delay times for butanol/oxygen/argon mixtures have been measured behind reflected shock waves at temperatures and pressures ranging from approximately 1200 to 1800 K and 1 to 4 bar. Electronically excited OH emission and pressure measurements were used to determine ignition-delay times. The influence of temperature, pressure, and mixture composition on ignition delay has been characterized. A detailed kinetic mechanism has been developed to describe the oxidation of the butanol isomers and validated by comparison to the shock-tube measurements. Reaction flux and sensitivity analysis illustrates the relative importance of the three competing classes of consumption reactions during the oxidation of the four butanol isomers: dehydration, unimolecular decomposition, and H-atom abstraction. Kinetic modeling indicates that the consumption of 1-butanol and iso-butanol, the most reactive isomers, takes place primarily by H-atom abstraction resulting in the formation of radicals, the decomposition of which yields highly reactive branching agents, H atoms and OH radicals. Conversely, the consumption of tert-butanol and 2-butanol, the least reactive isomers, takes place primarily via dehydration, resulting in the formation of alkenes, which lead to resonance stabilized radicals with very low reactivity. To our knowledge, the ignition-delay measurements and oxidation mechanism presented here for 2-butanol, iso-butanol, and tert-butanol are the first of their kind.
authors.affiliation: Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, New York, USA.
authors.forename: Jeffrey T
authors.initials: JT
authors.lastname: Moss
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Berkowitz
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Oehlschlaeger
authors.forename: Joffrey
authors.initials: J
authors.lastname: Biet
authors.forename: Valérie
authors.initials: V
authors.lastname: Warth
authors.forename: Pierre-Alexandre
authors.initials: PA
authors.lastname: Glaude
authors.forename: Frédérique
authors.initials: F
authors.lastname: Battin-Leclerc
mesh_terms: D000440:Butanols / Q000737:chemistry*; D003198:Computer Simulation; D007700:Kinetics; D008956:Models, Chemical; D010084:Oxidation-Reduction; D012044:Regression Analysis; D013237:Stereoisomerism; D013696:Temperature; D013997:Time Factors
chemical_list: D000440:Butanols