A Comprehensive Study of Methanol Kinetics in Freely-Propagating and Burner-Stabilized Flames, Flow and Static Reactors, and Shock Tubes

Abstract

An experimental and numerical study of methanol kinetics has been conducted. A detailed kinetic scheme was compiled which closely predicts properties of mixtures of methanol, oxygen, and inert for a variety of experimental configurations and conditions. The scheme incorporates the most recent kinetic information and was tested against experimental data for the propagation speeds and structure of laminar flames as well as the species concentration evolutions in flow reactors, static reactors, and shock tubes. The laminar flame speeds of atmospheric methanol/air mixtures were determined using the counter-flow flame technique over extensive lean-to-rich fuel concentration ranges and for initial mixture temperatures ranging from 318 to 368 K., while the experimental data on the laminar flame structure and from reactors and shock tubes were obtained from the literature. The scheme compiled herein includes the detailed C₁, C₂, and methanol submechanisms and yields close agreement with all of the experimental methanol/air laminar flame speeds as well as previously determined laminar flame speeds of mixtures of CH₄ and the C₂-hydrocarbons with air. The relative importance and influence of the individual reactions on the flame speed and reaction mechanism were assessed with the aid of sensitivity and species consumption path analyses. The study also demonstrates that accurate prediction of laminar flame speeds is only a necessary but not sufficient condition for the validation of the mechanism, and that results from the flame structure as well as reactors and shock tubes are also needed for further validation. Both flow and static reactor oxidation studies indicate that the reaction CH₃OH = OH → Products may have a slower rate than that reported in recent literature.