Alternativas tecnológicas para aproveitamento de resíduos de poda urbana como produtos de maior valor agregado

Abstract

In urban centers, the generation of solid waste prompts managers to seek innovative usage solutions that reflect society’s demand for environmentally friendly practices. In this context, this thesis aims to propose technological alternatives for the utilization of urban pruning waste (UPW) generated in the urban area of Curitiba, Paraná, for the production of briquettes for energy purposes and reconstituted wood particle boards. The panel manufacturing process was divided into two stages: (i) single-layer panels, with five different treatments, and (ii) multilayer panels, with two treatments, using different percentages of mixture between UPW and Pinus particles, bonded with low emission UF resin. UPW biomass characterization included granulometric and dimensional classifications, as well as genomic analysis in the sample, with a protocol for the identification of DNA from the species composing the particles. Regarding the physical-mechanical properties of the briquettes, tests were conducted for moisture content (MC), higher calorific value (HCV), apparent density (AD), durability (Dur), volumetric expansion, maximum load, and granulometric analysis. The panel quality analysis included density profile, density, determination of thickness swelling, moisture content, water absorption, modulus of elasticity, static bending strength, perpendicular tensile strength, and formaldehyde emission. The results indicated that, in the characterization of UPW, a value of 2.9 was determined for the slenderness ratio and average values for ash content of 3.4%, volatile materials 78.5%, and fixed carbon 18.1%. For the briquettes, an HCV of 4417 Kcal/g, AD of 21.05 MJ/m³, friability of 99.8%, and maximum load of 704.9 kgf were observed, placing the briquettes in Group 1, of better quality. Regarding single-layer panels, treatments T2 (25% UPW) and T3 (50% UPW) showed the best results, and among multilayer panels, there were no statistical differences. Formaldehyde emissions met the limits established in NBR 14810-2:2018, achieving E1 classification for all panels produced. The UPW employed in this study can be used for the production of briquettes for energy purposes as well as particle boards. The technical feasibility of UPW utilization for the manufacture of briquettes and particle boards adds to the valorization of this resource and positive sustainability aspects.