Experimental and model investigation of the low temperature oxidation and pyrolysis of 2-methyl-2-butene in a jet-stirred reactor

Species concentrations for 2-methyl-2-butene oxidation and pyrolysis were measured in a jet-stirred reactor at atmospheric pressure, in the temperature range of 650 to 1200 K and the residence time of 1.5 s. The model presented in literature was modified based on the high-level quantum calculated rate coefficients published, including 1,2-dimethyl-allyl (AC₅H₉[sbnd]C) + HO₂, 1,2-dimethyl-allyl + O₂, 1,2-dimethyl-allyl + 1,2-dimethyl-allyl, isoprene + H reaction classes. The modified model was validated against the measured species concentrations, ignition delay times and laminar flame speeds. The modified model can accurately predict experimental data under various conditions. Moreover, flux analysis showed that the major pathways were abstraction reactions that consumed more than 40% 2-methyl-2-butene. At lower temperatures, reactions of HO₂ addition, O₂ addition and radical self-combination were the dominant consumption path for allylic pentenyl radicals. Sensitivity analysis showed that HO₂ additions to AC₅H₉[sbnd]C radicals, forming AC₅H₉[sbnd]COOH, BC₅H₉-AOOH, and C₅H₉O oxy-radicals + OH played important roles in promoting the overall reactivity.