Enhancing In Situ Burning With Ferrocene for Improved Combustion and Reduced Smoke Production

In situ burning (ISB) is an efficient response strategy for oil spills; however, incomplete combustion and excessive smoke production hinder its wider application. In this study, the effectiveness of using ferrocene as additives to improve the thermal behaviors and kinetics of combustion of different crude oils (Hibernia, Hebron, Dilbit and Bitumen) and commercial Diesel was investigated using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques under atmospheric air condition. The TGA and DSC results revealed that the addition of 1.0 wt% ferrocene to crude oils and Diesel lowered the combustion oxidation reaction temperature up to 80°C, indicating reduced resistance and thermodynamic demand during ISB experiments. Iso-conversional kinetic modeling using Ozawa–Flynn–Wall (OFW) and Kissinger–Akahira–Sunose (KAS) showed a reduction in apparent activation energy (E_a) up to 35–50 kJ mol⁻¹ in Hibernia and Hebron, 87–182 kJ mol⁻¹ in Bitumen, and 12 kJ mol⁻¹ in Diesel, confirming enhanced ignition and reaction rates, whereas Dilbit exhibited a slight increase (~up to 2.6 kJ mol⁻¹). To better understand oil oxidation behavior and mechanisms during ISB, TG-FTIR (Fourier transform infrared spectroscopy) system was employed to analyze the evolved gases at various temperature stages. It was revealed that ferrocene facilitated oxygen addition, bond scission and decarboxylation reactions, resulting into enhanced breakdown of complex, high-boiling-point oxygenated hydrocarbons during ISB. Hence, ferrocene hindered the aggregation of molecular species into larger compounds, resulting in less smoke production in ISB and these findings will inform future ISB experiments in open water bodies.