Ketene (CH2CO) mechanism is a building block for developing combustion kinetic models of practical fuels. To revisit the combustion chemistry related to ketene, oxidation experiments of butane-2,3-dione (diacetyl, CH3COCOCH3), considered as an effective precursor of CH2CO, are conducted in a jet-stirred reactor (JSR) at 10 bar and temperatures ranging from 650 to 1160 K.

Identification and quantification of intermediates are achieved by Fourier transform infrared spectrometry, gas chromatography, and mass spectrometry. A kinetic model of diacetyl is constructed based on recent theoretical and modeling studies on diacetyl and ketene, which has been validated against the present data and experimental data of diacetyl and CH2CO in literature. Generally, the present model can adequately predict most of them, and better predict the methyl-related intermediates under wide pyrolysis and combustion conditions than previous models. Based on modeling analyses, the unimolecular decomposition reaction of diacetyl is the dominant reaction pathway for fuel consumption under different equivalence ratio conditions, especially at high temperatures. Under lean conditions, both the H-atom abstraction reactions by methyl (i.e. CH3COCOCH3 + CH3 = CH4 +