Production of sawdust and chicken fat briquettes as an alternative solid fuel

Abstract

This study focuses on converting underutilized or discarded sawdust from Eucalyptus grandis (EG) and Pinus elliottii (PE), along with roasting chicken oil (RCO) and chicken visceral oil (CVO), into alternative briquettes. Employing heuristic methods and branch-and-bound techniques, 27 experiments were conducted based on a central composite design (CCD), including two central point repetitions. The energy density (ED) of the briquettes was evaluated immediately after production (EDi) and three months later (EDf). The higher heating value (HHV), thermogravimetric analysis (TGA) with its first derivative, and cost of each briquette were also characterized. Increasing chicken oil content improved HHV, initial ED, reduced ash content, and enhanced thermal degradation performance. However, exceeding 15% oil content caused wastage during pressing. Excessive CVO use is cost-prohibitive unless produced by the poultry industry. The optimal briquette was obtained in experiment 9 with 21.25% EG, 63.75% PE, 3.75% CVO, and 11.25% RCO by mass. Structural neighbors were identified based on this composition. Sawdust type and particle size had minimal impact on the results.