Development of a Reduced Multi-Component Kinetic Mechanism for Marine Heavy Fuel Oil Substitutes

To mitigate the environmental impact resulting from the combustion of traditional heavy fuel oil (HFO) in marine diesel engines, this work proposes a simplified chemical kinetic mechanism specifically designed for alternative fuel applications. To emulate the properties of heavy fuel oil (HFO), this study formulated a surrogate fuel comprising n-dodecane, propylene, and α-Methylnaphthalene as its primary constituents. Detailed kinetic mechanisms of n-dodecane and propylene were analyzed using reaction path and temperature sensitivity analyses. Mechanism simplification was conducted by adopting the Direct Relation Graph Method with Error Propagation (DRGEP), the combined Direct Relation Graph with Error Propagation and Sensitivity Analysis (DRGEPSA), an augmented DRGEPSA including additional sensitivity evaluation, and the Full Species Sensitivity Analysis (FSSA) method. Consequently, a skeletal n-dodecane scheme comprising 55 species and 585 reactions, along with a simplified propylene scheme containing 116 species and 730 reactions, was established. These were integrated with a condensed α- methylnaphthalene mechanism to yield a comprehensive surrogate HFO scheme comprising 146 species and 843 reactions. The assembled mechanism was validated within the Homogeneous Charge Compression Ignition (HCCI) engine framework in ANSYS Chemkin and benchmarked against a reference toluene fuel (TRF) mechanism. Results show that the proposed mechanism maintains prediction errors within 10% for both temperature and pressure, demonstrating good accuracy and applicability. The skeletal mechanism also exhibits reliable performance in capturing combustion characteristics, indicating its potential for practical engine simulations involving heavy fuel oil substitutes.