KINETIC MODELING OF THE THERMAL-CRACKING OF HYDROCARBONS .2. CALCULATION OF ACTIVATION-ENERGIES

The kinetic modeling of the thermal cracking of hydrocarbons is based upon a free-radical reaction scheme containing several hundred reactions. The most important problem to be solved hereby is to assign values to the corresponding reaction rate constants. A group contribution type of method is introduced for the calculation of activation energies. The contributions are based on an analysis of the mechanism of the reactions and on the relative stabilities of the reacting species. A thermodynamic analysis of the reaction network leads to relationships between these contributions and reduces their number. A literature data base provides numerical values for the contributions.