COMPREHENSIVE KINETIC-MODEL FOR THE LOW-TEMPERATURE OXIDATION OF HYDROCARBONS

The low-temperature oxidation chemistry of linear and branched alkanes is discussed with the aim of unifying their complex behavior in vario us experimental systems using a single derailed kinetic model. New exp erimental data obtained in a pressurized flow reactor, as well as in b atch- and jet-stirred reactors, are useful for a better definition of the region of cool flames and negative temperature coefficient (NTC) f or pure hydrocarbons from propane up to isooctane. Thermochemical osci llations and the NTC region of the reaction rate of the low-temperatur e oxidation of n-heptane and isooctane in a jet-stirred flow reactor a re reproduced quite well by the model, nor only in a qualitative way b ur in terms of the experimental frequencies and intensities of cool fl ames. Very good agreement is also observed for fuel conversion and int ermediate-species formation. Irrespective of the experimental system, the same critical reaction steps always control these phenomena. The r esults contribute to the definition of a limited set of fundamental ki netic parameters that should be easily extended to model heavier alkan es.