Avaliação do Ciclo de Vida da reciclagem de garrafas PET em contexto brasileiro: rotas B2B (bottle-to-bottle) e B2F (bottle-to-fiber)

Abstract

This study aimed to carry out the Life Cycle Assessment (LCA) to deepen and broaden the understanding of the environmental impacts of two different routes for Polyethylene Terephthalate (PET) recycling in the Brazilian context: 1) the production of Post-Consumer Recycled Polyethylene Terephthalate (PET-PCR), for application in food packaging, by the bottle-to-bottle (B2B) process; and 2) the production of Recycled Polyester Fiber, for use in textile artefacts, by the bottle-to-fiber (B2F) process. The scope of the LCA was “cradle to the gate”, ranging from the logistics of post-consumer PET bottles to the final product obtained by the industrial processing steps. Highlight in this work, the primary data are all real obtained from a recycling unit located in Poços de Caldas-MG, with a recovery capacity of 20000 t/year of post-consumer PET bottles. Secondary data were collected from relevant literature and LCA available databases, with an emphasis on data of production system of electricity, natural gas and diesel, which represent the Brazilian energy matrix. The environmental impact categories evaluated were the most cited in the literature, for works related to the theme: Global Warming Potential, Terrestrial Acidification, Abiotic Resources Depletion, Water Scarcity, Ozone Depletion Potential, Freshwater Ecotoxicity and Human Toxicity. Methodologies recommended for the Brazilian context were used for the impact assessment. A comparison between B2B and B2F was done, and it was observed that, of the nine categories evaluated, in seven of them B2F had a greater environmental impact potential. Related to similar products, it was possible to compare the results with those of studies for other regions, in the categories Global Warming Potential and Abiotic Resources Depletion, fossil; and also for some characteristics related to the transport of PET bottles, such as average distance and load. The environmental hotspots identified were related to the diesel consumption by trucks in bottle logistics, and to the consumption of natural gas and electricity in industrial recycling processes. Opportunities were identified and proposals were discussed for environmental gains. The impacts of changes in bottle logistics were assessed, through the resizing of PET bottle bales, the use of the most appropriate vehicle and adopting the transport distance of the collected material compatible with international practices.