A Molecular Modelling Investigation of Selected Gasoline Molecules to Relate Oxidation Pathways to their Autoignition Behaviour 2007-01-0005
An adaptation of the procedure originally developed by Twu and Coon for blend octane prediction is described. The technique is based on a graded index describing an aspect of the negative temperature coefficient (NTC) autoignition behaviour of a fuel. It is further postulated that the fuel's NTC behaviour can be linked to the transition state activation energy barriers involved in the first internal hydrogen abstraction by the alkylperoxy free radical. Density-functional theory (DFT) calculations were employed to assess this hypothesis and the results were able to explain the difference between the ignition behaviour of a number of selected fuel components. The calculated NTC assignments, which were directionally consistent with the DFT results, were used successfully to determine the blend octane rating.
Citation: Viljoen, C., Yates, A., and Coetzer, R., "A Molecular Modelling Investigation of Selected Gasoline Molecules to Relate Oxidation Pathways to their Autoignition Behaviour," SAE Technical Paper 2007-01-0005, 2007, https://doi.org/10.4271/2007-01-0005. Download Citation
Carl L. Viljoen, Andy D. B. Yates, Roelof L. J. Coetzer
University of Cape Town, Republic of South Africa, Sasol Technology Research and Development, Republic of South Africa