Detailed chemical kinetic modeling of butylbenzene pyrolysis

A chemical kinetic model was constructed for the pyrolysis of butylbenzene. The mechanism was based on free radical reactions. All relevant reactions were considered, and a final selection of 60 reactions involving 29 molecules and free radicals was made. The rate constants and thermodynamic parameters were taken from the literature or estimated using accepted literature methods such as group additivity. The results from the model were compared to experimental rates and product selectivity for butylbenzene pyrolysis over a temperature range of 778 K to 868 K and to an experimental rate at 923 K. The rates agreed within a factor of two and were usually much closer. The experimental and theoretical yields of the major products, styrene, ethane, toluene, and propylene, agreed within two percentage points. The agreement for seven minor products was not quite as good, with the worst case being an overprediction of the yield of allylbenzene by a factor of 2.6.