USE OF LIGNOCELLULOSIC WASTE FROM TREE PRUNING IN THE FEDERAL DISTRICT FOR BIOFUEL PRODUCTION
LIGNOCELLULOSIC; BIOFUEL; TORREFACTION.
In Brazil, the management of solid urban waste (MSW) is a problem that has spread for years. In Brasília city, lignocellulosic residues (tree pruning), present particular difficulties that result in landfill overload and are closely related to environmental problems. As a technological proposal for energy use and environmental remediation, the objective of this work is to characterize the biofuel constituted by lignocellulosic residues of Brasília. For this, a mixture of the six species with the greatest representativeness in the forest ecosystem of the city was established. The proportionally representative mixture was subjected to torrefaction treatment in a thermogravimetric analyzer (TGA) at temperatures of 225, 250 and 275 °C for 60 minutes under inert conditions. In natura samples and torrefied product were chemically analyzed (proximate and elemental analysis and calorific value). A numerical model for was established to determine the kinetics of thermochemical degradation enabling the prediction of blend mass loss at different torrefaction severities. Torrefaction severity was assessed using the Torrefaction Severity Index (TSI) and the Torrefaction Severity Factor (TSF) and models for predicting the properties of torrefied products were statistically evaluated. The gasification of the torrefied product was compared to the raw material, providing information on the use of this biochar for the production of syngas. Finally, the raw product characterization data allowed to establish an optimal mixture through a multicriteria analysis aiming its application as biofuel. Torrefaction treatment showed a significant improvement in the properties of the samples (burning power, homogeneity and hydrophobicity), enhancing it ideal for downstream applications (direct firing and gasification). The indices used to measure the severity of roasting showed effectiveness in terms of accuracy in predicting the chemical properties of the treated products. The results obtained provided quantitative information on the thermal xi and kinetic improvement of biofuel degradation, allowing an analysis of its viability and energy potential.