Petroleum Science and Technology, 2025 (SCI-Expanded, Scopus)
In the study, raw and torrefied chicken manure (CM) and rose pulp (RP), blended with low-grade Kale lignite (KL), to enhance the understanding of their co-combustion behavior. While previous studies have independently examined biomass or its blends with coal, the coupled effects of torrefaction and kinetic synergy in triple-component fuel systems remain largely unexplored. Here, this work addresses this gap by analyzing combustion indices, and model-free kinetic parameters via the Flynn–Wall–Ozawa method. CM and RP were torrefied at 275 °C for 1 hr and six fuel blends were prepared containing 20–34 wt% KL with proportional amounts of CM and RP. Thermogravimetric (TG) analyses were performed in the range of 25–1,000 °C under air atmosphere at 5, 10, 15, and 20 °C min−1. Torrefaction significantly improved fuel characteristics by reducing moisture (CM: 7.16%–0.10%) and increasing fixed carbon (RP: 15.63%–19.43%) and calorific value (RP: 4,106–4,284 kcal/kg). Activation energies were reduced post-torrefaction (CM: 127.14–69.61 kJ/mol), indicating enhanced devolatilization and thermal uniformity. Synergistic effects in raw blends (R2 = 0.7435) weakened after torrefaction (R2 = 0.9881), reflecting increased additive behavior. These results reveal that torrefaction not only alters fuel composition but also modulates combustion reactivity and kinetics.