Rate Constants of CH4 + M?CH3 + H + M and CH3OH + M?CH3 + OH + M over 1400-2500 K

Abstract

Rate constant k1 of CH4 + MCH3 + H + M was determined from time profiles of IR emission at 3.4 μm obtained for a CH4/Ar mixture heated by incident shock waves at pressures 0.40–0.82 atm and temperatures 1400–2500 K. The emission decrease due to CH4 decay in a very short period at the shockfront was investigated. Computer modeling for the decrease gave the k1 value as: 3.0 × 1016 exp(−81.0 kcal/RT) cm3 mol−1 s−1. The k1 value was almost the same as those reported by all authors except for the report by Klemm et al. The same technique was used for determining the rate constant k2 of CH3OH + MCH3 + OH + M and a new value was proposed as k2 = 4.2 × 1016 exp(−66.8 kcal/RT) cm3 mol−1 s−1. © 2000 John Wiley & Sons, Inc. Int J Chem Kinet 32: 1–6, 2000