Experimental and modeling study of the low to high temperature oxidation of the linear pentanone isomers: 2-pentanone and 3-pentanone

Short-carbon-chain ketones are known for their high octane numbers, their knock resistance, and their low soot emission. However, studies on the combustion behavior of ketones, particularly in the low temperature regime, are sparse, and small ketones as acetone and butanone show limited low temperature chemistry (LTC). Therefore, saturated linear five-carbon ketones are good candidates to better understand the LTC of ketones and the effect of the functional carbonyl group. In this study, the ignition delay times of stoichiometric non-diluted 2- and 3-pentanone-oxygen-inert gas mixtures were measured in a rapid compression machine at pressures between 20 and 40 bar and temperatures ranging between 650 and 950 K. Furthermore, the mole fraction profiles of fuel, oxygen, intermediate species, and products were measured in a laminar flow reactor coupled with molecular-beam mass spectrometry at 0.97 bar, an equivalence ratio of 0.8 and temperatures ranging from 800 to 1050 K, to achieve a better understanding of the oxidation process of linear pentanones. A consistent detailed kinetic model was developed and validated against the newly measured experimental data for 2-pentanone and 3-pentanone to provide insight into the oxidation mechanism of pentanones. The model shows also good agreement with available data from the literature, including ignition delay times measured in a shock tube, speciation in a flat flame burner and laminar burning velocities.