Beneficiamento do resíduo do coco verde da cidade de João Pessoa para produção de péletes

Abstract

The green coconut husk (Coco nucifera L.) is a common municipal solid waste in the coastal areas of Brazil, and its improper disposal poses a sanitary and environmental challenge. In 2023, Paraíba produced approximately 69 million coconut fruits, resulting in an estimated public cost of R$ 11.9 million for the disposal of this waste, which could be valued but instead contributes to environmental pollution. In light of the growing global focus on mitigating climate change and transitioning to alternative energy matrices, biofuels derived from residual biomass are gaining prominence. Compacted biomass, used as solid fuel, offers advantages such as higher calorific power and density. In Brazil, the production of compacted biomass, such as pellets and briquettes, is still not regulated, and ISO 17225 is often adopted to reach the international market. The objective of this study was to investigate the feasibility of producing pellets from the green coconut waste in João Pessoa, aiming for the international market. The literature review conducted from 2007 to the present revealed a lack of data on green coconut consumption in the city, with the most robust data dating back to 2007, which hinders the implementation of sustainability actions and the utilization of this waste. The thermogravimetric curves in a synthetic atmosphere showed the expected behavior for coconut, presenting three phases of degradation. The results for moisture (9.7%), ash (4.0%), and lower heating value (LHV) of 15.68 MJ·kg⁻¹ comply with ISO parameters. However, the pellets obtained through the pelleting press showed unsatisfactory results: length (12.26 mm), diameter (9.97 mm), and bulk density (331.789 kg·m⁻³) did not meet ISO standards, negatively affecting the energy density (5202.45 MJ·m⁻³), which was significantly lower than that of other pellet publications. Future studies are essential to apply methodologies and analyses in accordance with ISO 17225- 6, using an industrial pelletizer to validate the use of green coconut waste from João Pessoa in the production of quality pellets for the international market.