High temperature pyrolysis of methane in shock waves. Rates for dissociative recombination reactions of methyl radicals and for propyne formation reaction

Abstract

Abstract The pyrolysis of 2% CH 4 and 5% CH 4 diluted with Ar was studied using both a single–pulse and time–resolved spectroscopic methods over the temperature range 1400–2200 K and pressure range 2.3–3.7 atm. The rate constant expressions for dissociative recombination reactions of methyl radicals, CH 3 + CH 3 → C 2 H 5 + H and CH 3 + CH 3 → C 2 H 4 + H 2 , and for C 3 H 4 formation reaction were investigated. The simulation results required considerably lower value than that reported for CH 3 + CH 3 → C 2 H 4 + H 2 . Propyne formation was interpreted well by reaction C 2 H 2 + CH 3 → P ‐C 3 H 4 + H with 𝓀 = 6.2 × 10 12 exp(−17 kcal/ RT ) cm3 mol −1 s −1 .