A utilização da biomassa lignocelulósica proveniente de resíduos domésticos tem se tornado uma escolha favorável na produção de bioenergia. No estado de Minas Gerais, a cadeia produtiva do pequi (Caryocar brasiliense Camb.) desempenha importante papel econômico e social. No entanto, a comercialização em grande escala desse produto pode gerar resíduos que, se não forem adequadamente gerenciados, representam um desafio ambiental significativo. Neste trabalho, foi avaliado o potencial energético da biomassa da casca de pequi para confecção de briquetes em diferentes proporções de umidade. Foram avaliadas propriedades físicas, mecânicas e térmicas da biomassa in natura em estudo. A caracterização imediata da biomassa revelou um alto teor de material volátil (74,41%), de carbono fixo (22,69%) e cinzas (2,90%), além de um poder calorífico de 14,23 MJ kg-1, mostrando a eficácia do material para produção de energia. A análise química evidenciou 69,38% de extrativos, 10,27% de lignina e 20,35 % de holocelulose. A análise termogravimétrica da casca se mostrou similar com a termo decomposição de biomassas lignocelulósicas. A confecção dos briquetes foi realizada em uma prensa hidráulica em diferentes proporções de umidade (5%, 7,5% e 10%). Os testes de resistência à compressão mostraram que briquetes com menor umidade possuem maior resistência. Os resultados deste estudo sugerem que a densificação da casca de pequi não apenas reduz significativamente o volume dos resíduos, como também resulta em uma diminuição de aproximadamente 90,42% do peso total, facilitando seu manejo e armazenamento, mas também oferece uma solução sustentável para a produção de bioenergia.

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.

The valorization of agroforestry residues, such as Caryocar brasiliense (pequi) shells, through biochar production represents a promising strategy for developing sustainable substrates for forest seedling production. This study aimed to evaluate the effects of incorporating pequi shell biochar, produced at different pyrolysis temperatures (350, 400, and 450 °C), on the physicochemical properties of substrates and the germination performance of Anadenanthera colubrina (angico-vermelho) seeds. A total of 26 substrate formulations were tested, containing different proportions of biochar (2.5, 5, 7.5, and 10% v/v), combined with subsoil and commercial substrate. The results showed that increasing the pyrolysis temperature led to higher pH, cation exchange capacity (CEC), and availability of nutrients (P, K, Ca, Mg), significantly improving germination conditions. Principal Component Analysis (PCA) revealed a positive correlation between germination performance and attributes such as pH, CEC, P, Ca, and Mg, and a negative correlation with aluminum content. The treatment with 5% biochar produced at 450 °C combined with commercial substrate yielded the highest emergence rates. It is concluded that pequi shell biochar, especially when produced at higher pyrolysis temperatures, has high potential as an input for substrate formulation in the production of Anadenanthera colubrina seedlings, with promising applications for other forest species as well.

Caryocar brasiliense Camb., popularly known as pequi, is a tree species native to Brazil with significant cultural, social, and environmental value, especially in the northern region of the state of Minas Gerais. However, during its commercialization process, a significant challenge is the proper utilization of the waste generated from its shell. This study aims to characterize the biomass and charcoal obtained from pequi bark, evaluating different carbonization temperatures (350, 400, and 450°C). The lignocellulosic characterization indicated a high content of extractives (56.82%) and holocellulose and lignin contents of 29.43% and 13.74%, respectively. The proximate analysis showed 71.36% volatile material, 20.63% fixed carbon, and 8.01% ash, while the calorific value found for the biomass was 18.99 MJ kg-1. In the charcoal, increasing the final carbonization temperature was directly proportional, resulting in higher percentages of ash, fixed carbon, pH, electrical conductivity, and calorific value, with the exception of volatile material and charcoal gravimetric yield, which decreased. The results demonstrated the technical feasibility of converting pequi bark into charcoal, with potential applications in the energy sector, effluent treatment, and as a soil conditioner. It also contributes to regional sustainable development and the mitigation of greenhouse gas emissions.