Kinetic Modeling of the Propyl Radical (beta)-Scission Reaction: An Application of Composite Energy Methods

In this work, propyl radical (beta)-scission reaction kinetics and energetics were investigated using quantum chemical Gaussian-3 (G3) and complete basis set (CBS) composite energy methods. Experimental thermodynamic and kinetic data were used to assess the accuracy of these calculations. The CBS model proved to have good agreement with the experimental data, which indicates that it is a good method for studying other hydrocarbon cracking reactions involving large species. Furthermore, a kinetic model with pressure and temperature effects was proposed. For P =< P0, k = (2.59 × 10^11) × P0.40 × e(-13618.16/T); for P > P0, k = (2.70 × 10^13) × e(15117.33/T), where k is the reaction rate constant (in units of s-1), P is the pressure (in units of kPa), T is the temperature (in units of Kelvin), and the switching pressure P0 can be calculated as P0 = (1.53 × 10^9) × e(-10610.24/T).