Comprehensive kinetic modeling and shock tube study of acetone pyrolysis and oxidation

Acetone (CH₃COCH₃) is a key intermediate and a representative oxygenated volatile organic compound (OVOC) relevant to biofuels, atmospheric chemistry, and advanced propulsion systems. In the current study, shock tube pyrolysis experiments for acetone/Ar mixtures were performed over the temperature range of 1300–1952 K at atmospheric pressure, utilizing laser absorption diagnostics at 4854 nm and 3175 nm to monitor the temporal evolution of carbon monoxide (CO) and methane (CH₄), respectively. In addition, ignition delay time (IDT) measurements were conducted in a shock tube for CH₃COCH₃/Ar/O₂ mixtures at three equivalence ratios (φ = 0.5, 1.0, and 2.0) over the temperature range of 1274–1601 K and 1.0 atm. The CO time-history data provided direct constraints on the unimolecular decomposition reaction R1 (CH₃COCH₃ (+M)=>CH₃CO + CH₃ (+M)), yielding a rate constant of k_R1 (1304–1952 K, 1.0 atm) = 9.0 × 10¹³ exp (−66,500 cal/mol/RT) s⁻¹, with an uncertainty of +28.7 %/−28.2 %. Additionally, CH₄ time-histories and IDTs measurements combined with sensitivity analysis were employed to refine the H-abstraction reactions R2 (CH₃COCH₃ + CH₃<=>CH₃COCH₂ + CH₄) and R3 (CH₃COCH₃ + H<=>CH₃COCH₂ + H₂), respectively. A detailed kinetic model of acetone consisting of 41 species and 284 reactions was developed based on the FFCM-1 framework and optimized skeletal sub-model of acetone with updated rate constants of R1, R2 and R3. Validation against a wide range of literature data, including IDTs, laminar flame speeds and speciation data from literature, demonstrates the robustness and accuracy of the optimized kinetic model. This work highlights the critical role of laser-based diagnostics in resolving key elementary reactions and illustrates the advantages of compact, well-calibrated kinetic models for high-temperature acetone combustion research.