Physicochemical and Energy Properties of Charcoal Briquettes Obtained from Pequi (Caryocar brasiliense Camb.) Shells Without Binders: Influence of Moisture Content and Carbonization Temperature

Bioenergy production from agro-industrial waste has the potential to contribute to climate change mitigation. In Brazil, the pequi (Caryocar brasiliense Camb.) production chain makes an economic, environmental, and social contribution. However, the collection and processing of the fruit produce large amounts of waste, such as the peel, whose improper disposal leads to significant environmental impacts. This study evaluated how moisture and carbonization temperature influence the energy properties of charcoal briquettes made from pequi peel waste. Carbonization was performed at two final temperatures (360 °C/480 °C) with a heating rate of 1.5 °C min−1 and residence times of 4 h and 5 h 20 min, respectively. Carbonization yields were calculated based on dry mass. Briquettes were produced from pequi peel at moisture contents of 5%, 7.5%, and 10% (wet basis). After carbonization, the charcoal briquette samples were characterized by proximate analysis, higher heating value (HHV), bulk density, energy density, and mechanical durability. Carbonization temperature exerted a more pronounced effect on the properties of the carbonized briquettes than the initial moisture content. Carbonization at 480 °C increased the fixed carbon content (76.38%, 74.25%, and 75.10% for treatments 1, 2, and 3) and the HHV (25.10–25.31 MJ kg−1), while reducing the gravimetric yield (32.84–33.25%). The influence of moisture content was more evident in carbonizations carried out at 360 °C, indicating a temperature-dependent interaction. The use of pequi peel for solid biofuel production promotes the valorization of agro-industrial residues and supports strategies aimed at the circular bioeconomy and the decarbonization of the energy matrix.