Pyrolysis of ethylbenzene

Abstract

The pyrolysis of ethylbenzene has been studied using a static reactor. At low conversion hydrogen and styrene are the major products together with methane, toluene, ethylene, ethane and benzene plus traces of higher molecular-weight hydrocarbons. The pyrolysis is a chain reaction with a chain length of the order of 10 initiated by PhC₂H₅→ PhCH₂+ CH₃ for which k/s^–1= 10^{14.4 ± 1.1} exp (–293 ± 18 kJ mol^–1/RT) based on an average of toluene and methane yields. This agrees well with previous work involving toluene and aniline carriers. The results may be explained by a complex mechanism involving free radicals, CH₃, PhCH₂, PhCHCH₃, PhCH₂CH₂, C₂H₅, Ph and H.

Termination appears to occur mainly by the reaction 2PhCHCH₃→ PhCH:CH₂+ PhC₂H₅. For the reaction PhCHCH₃→ PhCH:CH₂+ H a rate constant k/s^–1= 10^15.9 exp (–217 kJ mol^–1/RT) was deduced.