Autoignition of surrogate biodiesel fuel (B30) at high pressures: Experimental and modeling kinetic study

Ignition delay times of surrogate biodiesel fuels were measured in a high-pressure shock tube over a wide range of experimental conditions (pressures of 20 and 40 bar, equivalence ratios in the range 0.5–1.5, and temperatures ranging from 700 to 1200 K). A detailed chemical kinetic mechanism developed for the oxidation of a biodiesel fuel and a B30 biodiesel surrogate (49% n-decane, 21% 1-methylnaphthalene, and 30% methyloctanoate in mol%) was used to simulate the present experiments. Cross reactions between radicals from the three fuel components and reactions of methylnaphthalene oxidation recently proposed in the literature were introduced into the model in order to improve ignition delay time predictions at low temperatures. The new scheme (7865 reversible reactions and 1975 species) yields improved model predictions of concentration profiles measured earlier in a jet-stirred reactor, and also represents fairly well the present experimental data over the entire range of conditions of this study. Sensitivity analyses and reaction path analyses were used to rationalize the results.