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-linewi dth laser absorption of methyl radicals at 216.6 nm. The experiments w ere 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. ( C) 1993 John Wiley & Sons, Inc.