Shock tube study and kinetic modeling of ethyl acetate/acetone/ethanol pyrolysis and oxidation: Non-linear blending effects

Ethyl acetate (EA), acetone (AC), and ethanol (ET) are common organic solvents used in industrial production and explosives recovery, and are also used as oxygenated fuels. These volatile substances pose explosion hazards, but kinetic studies of their blends remain limited. In this work, ignition delay times (IDTs) were measured for neat AC, neat ET, and EA/AC/ET binary and ternary blends in a shock tube at atmospheric pressure over 1186–1452 K under stoichiometric conditions. CO and CH 4 time histories were also obtained during pyrolysis over 1435–1827 K using laser absorption diagnostics at 4854 and 3175 nm, respectively. Previously reported neat EA data were used as reference cases for identifying blending effects. The EA/AC blend exhibited IDTs intermediate between those of the two neat fuels, whereas the EA/ET and AC/ET blends showed shorter IDTs than their less reactive neat-fuel components. The ternary blend exhibited IDTs close to those of neat EA. Compared with linear additivity, the ternary blend exhibited the largest decrease in CO and increase in CH 4 , while the binary blends showed smaller deviations. A detailed kinetic model (639 species, 3403 reactions) was developed by refining the ET and AC sub-mechanisms within a validated EA framework. Rate constants for six key elementary reactions were updated based on literature data and direct shock tube measurements of the primary AC decomposition reaction. The model was validated against present measurements and literature data. Reaction pathway and sensitivity analyses indicate that, during pyrolysis, the enhanced CH 3 pool promotes H-abstraction from fuels and intermediates, shifting the reaction flux toward CH 4 formation while suppressing CO formation. During oxidation, the non-linear IDT behavior results from a partial offset between enhanced radical consumption and OH regeneration, which keeps the ternary blend IDTs close to those of neat EA. These results improve the kinetic understanding of complex oxygenated blends, guiding explosion hazard assessment.