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A kinetic mechanism for a multicomponent gasoline surrogate consisting of isooctane, n-heptane, toluene, and 1hexene is developed, including types of cross reactions. The mechanism comprises 1392 species and 6019 reactions. Validation results show good agreement with experimental observations for pure components and their various mixtures. Moreover, the multicomponent surrogate and a toluene reference fuel (TRF) surrogate are validated for a research gasoline fuel using the present model. The multicomponent surrogate perfomed better in predicting experimental data compared to the TRF surrogate because of the addition of 1-hexene. Effects of cross reactions on the ignition delays are discussed. It is found that three types of cross reactions, namely, reactions between pure components, reactions between pure components and alkylperoxy radicals, and reactions between pure components and benzylperoxy radicals, take effect for the acceleration of ignition delays in a shock tube and a homogeneous charge compression ignition engine. Accelerate effect is more pronounced at high-pressure, lowtemperature, and fuel-rich conditions. The model with cross reactions between pure components and alkylperoxy radicals ignites the earliest, and the model with reactions between pure components ignites the latest. Cross reactions between decomposition intermediate species (ethylene, propene, isobutene, phenyl, and benzaldehyde) have no influence on ignition delay times.

The recycling of exhaust heat in internal combustion engines to dissociate the methanol, followed by its blending with methanol to produce engine fuel, is promising for improving the efficiency of engines, and reducing emissions. The kinetic model MEOHSYNGAS1.0 for the methanol–syngas fuel is proposed by reducing the detailed chemical kinetic model (Mech15.34). Shock tube experiments are conducted to measure the ignition delay time of methanol blended with dissociated methanol gas at different dissociated methanol ratios (0, 30, 50, and 100%). The model is validated by the experimental data of the present work and with data from the literature. The effects of the equivalence ratio, pressure, and dissociated methanol ratio on the ignition delay time are investigated through reaction path analysis and sensitivity analysis. When the dissociated methanol ratio does not surpass 50%, the ignition delay time increases with the increase in the dissociated methanol ratio, which is more obvious in the low temperature range, and but decreases with the increase in temperature.

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