Autocatalytic gas-phase dehydrogenation of ethane

Homogeneous gas-phase pyrolysis of ethane by continuous CO₂ laser irradiation was used in our experiments for bulk heating of the reaction mixture. Laser energy was absorbed by ethylene, the main product of ethane dehydrogenation, and transferred to the reaction medium via collisional relaxation. A mechanism of ethane dehydrogenation is suggested to describe the pyrolysis process. The mechanism is autocatalytic in respect of ethylene and includes ethane?Cethylene interaction with the formation of methyl and propyl radicals. Rate constants of elementary reactions, selectivity, and yields of pyrolysis products were determined. The composition of ethane dehydrogenation products determined in the experiments was substantially different from the calculated thermodynamic equilibrium composition.