Logging wastes from sustainable forest management as alternative fuels for thermochemical conversion systems in Brazilian Amazon

Abstract

Logging wastes of tropical species managed sustainably in the Brazilian Amazon are promising for replacing fossil fuels. However, their use in local energy systems is challenging concerning many mixed-species with unknown properties. This study focuses on the energy characterization of the logging wastes from twenty commercial Amazon species harvested in a sustainable management plan and their energy equivalence to fossil fuels. The wood species were grouped by principal component analysis according to their basic density, moisture content, maximum moisture content, heating value, energy density, and chemical composition. Basic density (0.525–0.895 g cm−3), energy density (9.4–16.8 GJ m−3), ash (0.3–2.5%), and total extractives (1.8–17.9%) showed wide interspecific variations. On the other hand, the carbon content (49.2–52.4%), total lignin (30.2–38.1%), fixed carbon (16.5–22.0%), volatile matter (76.7–82.8%), and higher heating value (19.1–20.9 MJ kg−1) varied less among species. D. excelsa, M. elata, P. altissium, and G. glabra wastes surpassed conventional planted species for bioenergy applications. The logging wastes formed four groups with similar properties aiming at energy systems. The fuelwood value index ranked wastes of D. excelsa wood as the most promising for bioenergy. Finally, D. excelsa wood wastes presented the largest mass of CO2eq fixed in 1 m3 of logging wastes (1,687 kg), meaning that the use of 1 m3 of these wastes would mitigate the emission of 1,687 kg of CO2eq.