Reactions via Chemically Activated Methanol and their Meaning for the Modeling of CH₄-Air Flames and CH₃OH-Air Flames

Abstract

The reaction CH₃+OH plays an important role for the modelling of laminar burning velocities of CH₄-air flames. Experimental data on its rate coefficient are scarce and the importance of this reaction is shown by rate coefficients obtained recently from theoretical models. For CH₃OH-air flames the reaction CH₂OH+H→ products is likewise important and to a lesser extent so is the reaction CH₃O+H. At higher temperatures no experimental data exist on these reactions and it has been tried in recent modelling studies to calculate rate coefficients for CH₃O+H from those of CH₃+OH by using equilibrium considerations. This approach if applied to a multiple channel reaction is generally dangerous, and indeed in this particular case by confusing the CH₃O and CH₂OH exit channels a rather misleading rate expression was obtained for the reaction CH₃O+H→.CH₃+OH.