Life cycle assessment of sawn wood processing in southern Brazil

The present article aimed to evaluate the potential environmental impacts of sawn wood processing in a company located in southern Brazil using the life cycle assessment (LCA) method. The case study was based on a medium-sized sawmill that produces sawn wood in Lages, Santa Catarina state, Brazil. The functional unit of the system was 1 m³ of sawn wood products for the consumer market. Data were collected through visits and contact with specialists at the companies. SimaPro was the simulation tool used with the Ecoinvent database and ReCiPe 2016 was the environmental impact method chosen for the midpoint and endpoint categories. The log yard corresponded to the highest steel use and lowest diesel input in the system. Thermal energy generation – specifically the biomass boiler operation – corresponded to the highest quantity of pollutants emitted into the atmosphere. The categories related to the most significant environmental impacts throughout the production process were human carcinogenic toxicity (2.47 kg 1,4-DCB), ozone formation – human health (5.20 × 10 -2 kg NOx eq ), freshwater ecotoxicity (0.82 kg 1,4-DCB), marine ecotoxicity (1.15 kg 1,4-DCB), and ozone formation - terrestrial ecosystems (5.23 × 10 -2 kg NOx eq ). The environmental hotspots of the system were the log yard, thermal energy generation, and the drying process. The introduction of the steel structure into the analyses demonstrated that, on average, 48% of the environmental impact in the midpoint and endpoint categories can be attributed to the use of this raw material. The use of electrical energy as a power source for loaders and/or forklifts is an environmental alternative to be considered to reduce the environmental impact of sawn wood processing, looking for sustainable production.