Abstract: Simultaneously considering both high fidelity and low computational cost presents a significant challenge in modeling the pyrolysis and oxidation of fuels. In this work, a comprehensive kinetic model for the pyrolysis of n-alkanes covering n-heptane, n-decane, and n-dodecane has been developed based on the Minimized Reaction Network (MRN) method. The total mechanism consists of 32 species and 58 reactions, which are validated against pyrolysis experimental data and mechanisms of multi-sizes in numerical simulations. In the pressure range of 0.02 ~ 5.00 MPa and the temperature range of 573 ~ 1732 K, the ability of this mechanism to predict the pyrolysis conversion and gas production of n-alkanes with temperature, pressure, and time variations is comparable to that of the detailed mechanism. Especially at high pressures, the sub-mechanisms for n-decane and n-dodecane exhibit higher predictive precision regarding both fuel conversion rates and the profiles of alkenes and acetylene, making them suitable for engineering numerical simulations of fuel pyrolysis and heat transfer. The pyrolysis mechanism can also be coupled with oxidation reactions to construct combustion mechanisms.

Key words: Minimized reaction network method, Pyrolysis, n-Alkanes, Kinetic modeling