Kinetic modelling study of cyclo-alkane oxidation for transportation fuels

Abstract

Cyclo-alkanes are the major constituents of hydrocarbons in market fuels such as petrol, diesel, and aviation fuels. Diesel fuels derived from bituminous sands have up to 30 % of cyclo-alkanes. Besides that, cyclo-alkanes play a vital role in soot formation as they yield aromatic compounds through dehydrogenation. Thus, it is crucial to include cyclo-alkanes in the formulation of multi-component diesel surrogate fuel models. As a consequence, better prediction in the combustion and emission simulations can be achieved. In this study, a reduced cyclo-alkane kinetic model, namely methyl-cyclohexane (MCH) is developed for diesel engine applications. Here, the detailed MCH model with 1,540 species is served as the base model. The reduced MCH model is derived by performing mechanism reduction using five-stage reduction scheme. Accordingly, a reduced MCH model with 86 species is obtained after the reduction procedures. A 94% reduction in the mechanism size has been successfully achieved. Next, the reduced MCH model is validated against the detailed model with respect to ignition delay (ID) timings in zero-dimensional (0-D) simulations. Computed results by the reduced MCH model are in close agreement with the detailed model, with maximum deviation recorded at 33%. The reduced MCH model developed is ready to be used to represent cyclo-alkanes in multi-component diesel surrogate fuel models.