Detailed chemical kinetic model for oxygenated fuels

Abstract

A detailed chemical kinetic model is developed and tested for the combustion of C2 and C3 oxygenated fuels such as ethanol, DME (dimethyl ether), acetone and n-propanol. It is validated by comparing predictions with experimental data on the structure of low pressure burner stabilised premixed flames and laminar burning velocities over a wide range of equivalence ratios. Data from shock tube and stirred reactor studies has also been considered. The elementary reactions of ethanol and DME oxidation have been studied extensively and were used as a starting point for extension to C3 oxygenated fuels. The chemistry of acetylene which is one of major intermediate species in higher hydrocarbon flames was also updated to improve the reliability of the present mechanism and acetylene laminar burning velocities and low-pressure premixed lean and rich flames were also computed. The detailed mechanism features more than 1500 reaction steps and 269 species. The structure of laminar premixed flames are predicted by using measured temperature profiles and conditions cover fuel-lean and fuel-rich mixtures at low pressure. The profiles of reactants, products and major intermediate species are compared to experimental data from mass spectrometry and the overall agreement between the kinetic model and experimental data is satisfactory. An analytic study of fuel consumption pathways is carried out to understand the detailed consumption pathways. The present mechanism is also tested against laminar flame speeds by calculating freely propagating premixed flames to extend the understanding of the combustion characteristics of oxygenated fuels. A sensitivity analysis is also performed.