Autoignition of hydrocarbons in a batch reactor: Analysis of a reduced model

In the late 1960s Gray and Yang developed the first reduced kinetic model for the oxidation of hydrocarbon fuels that qualitatively described many features observed experimentally. Since then a number of reduced kinetic models have been proposed in the literature. In this contribution we analyse the steady-state behaviour of one such scheme. The chemical component of the model contains four chemical species undergoing six reactions. By making a pool chemical approximation this system is reduced to three coupled non-linear differential equations: a temperature equation and equations for two reactive chemical intermediates. It is shown that any steady-state solution of this model having a steady-state temperature greater than 420 K is non-physical as the steady-state concentrations of the chemical species are negative. Hence this particular scheme does not simulate closed-vessel experiments and is defective as an extension of the Gray-Yang model.