Shock Tube Measurement of the CH₃ + C₂H₆ → CH₄ + C₂H₅ Rate Constant

The rate constant for the CH₃ + C₂H₆ → CH₄ + C₂H₅ reaction was studied behind reflected shock waves at temperatures between 1369 and 1626 K and pressures from 8.6 to 47.4 atm in mixtures of methane, ethane, and argon. Ethylene time histories were measured using laser absorption of radiation from a carbon dioxide gas laser near 10.532 μm. The resulting rate constant data can be represented by the Arrhenius equation k (T) = 3.90 × 10¹³ exp(-16670 cal/mol/RT) cm³ mol^-1 s^-1. We believe this is the first study to extend experimental data for this rate constant to temperatures above 1400 K. The overall 2σ uncertainty of the current data is +18%/-21% resulting primarily from uncertainties associated with the influence of secondary reactions and the fitting of rapidly changing species time histories at the higher temperatures.