THE THERMAL DECOMPOSITION OF ETHANE: PART III. SECONDARY REACTIONS

Abstract

The kinetics of the secondary reactions producing methane, butane, and butene-1 in the pyrolysis of ethane have been investigated over the temperature range 550–726 °C and at pressures from 600–10 mm. The rate of secondary methane production was second order in ethylene at high pressures but was first order in ethylene at low pressures and high temperatures. In the latter region it is concluded that isomerization of the n-butyl radical to sec-butyl with subsequent decomposition to CH3 + C3H6 was the main source of methane. The rate of butane formation increased with time at low temperatures and decreased with time at high temperatures. It is shown that the decrease in rate was mainly due to the thermal dissociation of butane. The main source of butene-1 was probably decomposition of the n-butyl radical.