Abstract
A series of cracking experiments on 2-methylbutane (isopentane), 2-methylpentane, 2-methylhexane, and 2-methylheptane were carried out using a conventional flow type apparatus at 700°C and atmospheric pressure. Branched alkanes were highly diluted with nitrogen by about 10 times and the extent of decomposition ranged from 5.5 to 15 mole %.
The initial product distributions obtained were compared with those simulated on the basis of the free-radical chain mechanism proposed by Rice and Kossiakoff. It was found, from comparison of experiment with calculation, that the radical isomerization through intramolecular 1-4 transfer of H-atom in addition to generally accepted 1-5 transfer should be taken into account. In the present study, the rate of 1-4 transfer isomerization was assumed to be equal to that of β-scission of radicals because there is strain energy in 5-membered ring formation.
