Unraveling the kinetic and thermodynamic behaviours of hybrid biodiesel and its blend with fossil diesel during thermal degradation
Аннотация
Biodiesel is viewed as a possible replacement for fossil diesel, addressing environmental issues and the need for renewable energy sources. This study investigated the kinetic and thermodynamic behaviours of waste cooking oil (U)- Jatropha curcas oil (J) hybrid biodiesel (UJ-B) and UJ-B-diesel blends (UJ-B20 and UJ-B80) during thermal degradation. The physicochemical properties and thermal properties of the UJ-B and the blends were determined through various analytical techniques (ASTM standard procedures, FTIR, 1 H NMR, 13 C NMR and TG/DTG). The TGA data obtained were thereafter evaluated using the Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) isoconversional techniques to examine the kinetic and thermodynamic parameters for UJ-B and UJ-B20, which were subjected to thermally degradation at varied heating rates (5, 10, and 15 °C · min -1 ) with temperatures ranging from 30 °C to 900 °C under N 2 conditions. The UJ-B exhibited double weight loss steps, whereas the UJ-B20 showed a single, well-defined weight loss step. The FWO iso-conversional approach fitted the TGA data best, as demonstrated by the highest R 2 values in the range of 0.9123-0.9856 as compared to KAS iso-conversional approach with R 2 values in the range of 0.8942-0.9823. Average apparent activation energies were 83.08 kJ · mol -1 and 67.73 kJ · mol -1 for UJ-B and UJ-B20, respectively. Endothermic and high energy barrier thermal degradation process was validated by the positive Δ H ‡ and Δ G ‡ values. Conversely, the negative Δ S ‡ value confirmed a more ordered process. Considering both the kinetic and thermodynamic parameters, the reactivity of the UJ-B20 was obviously more intense compared to the UJ-B, which may be beneficial for the application in internal combustion engines. Thus, further research on the combustion of UJ-B and UJ-B-diesel blends in diesel engines is recommended to gain insight into their emission characteristics.
Ҳали таржима қилинмаган