A study of ethane decomposition in a shock tube using laser absorption of CH3

The rate coefficient for the unimolecular reaction, C₂H₆ → CH₃ + CH₃, was measured in reflected shock wave experiments using narrow-linewidth laser absorption of methyl radicals at 216.6 nm. The experiments were conducted in the falloff regime at the conditions 1350 to 2110 K, 0.58 to 4.4 atm, in 50 to 500 ppm C₂H₆/Ar and 190 ppm C₂H₆/N₂ mixtures. At temperatures below 1500 K, the measured rate coefficients are in good agreement with the expression of Wagner and Wardlaw (1989). Above 1500 K, the measurements fall increasingly below their predictions. © 1993 John Wiley & Sons, Inc.