Environmental Life Cycle Assessment of Bleached Pulp from Eucalyptus: Chilean Case

The forestry and pulp industry in Chile has been a significant contributor to the country’s gross domestic product (GDP), accounting for over 1.2% between 2018 and 2022. This sector is expected to continue growing in the coming years. The purpose of this study was to assess the environmental performance of the production of 1 tonne of short fibre bleached cellulose using the Kraft process in Chile. The assessment focused on quantifying the impact in 10 life-cycle impact categories, utilising the ReCiPe 2016 Midpoint (H) V.1.03 impact method. The evaluation followed a cradle-to-gate approach, considering the various stages including forestry activities involving biocides, fertilisers, and machinery, as well as transportation, and the subsequent industrial stage encompassing chemicals consumption, electricity usage, fuel consumption, and waste disposal. The assessment adhered to the life-cycle assessment guidelines specified in ISO 14040-44:2006 and utilised primary data from 2017, with a base year production of 1,495,000 tonnes of pulp. The results revealed that the industrial stage had the most significant environmental impact in eight out of the ten categories studied. Notably, the Global Warming Potential (GWP) reached 784 kg CO2eq/tonne of cellulose, which is noticeably higher in comparison to other countries but consistent with domestic and Ecoinvent 3.4 results. Additionally, biogenic emissions reached 3140 kg CO2biogenic/tonne of cellulose, primarily due to the combustion of waste wood and black liquor for energy recovery and electricity generation delivered to the national grid. The forestry stage was found to be the primary contributor to marine eutrophication (MAEU) and stratospheric ozone depletion (SOD), accounting for up to 86% of this environmental impact category. These results can be attributed to the usage of chemicals such as nitrogen-based fertilisers and biocides (fungi and herbicides). These findings provide quantified information that can facilitate informed comparisons with similar processes and aid in decision-making to improve the forestry-industrial sector. Emphasis should be placed on those activities that have the most significant impacts on the Chilean pulp sector, thereby promoting sustainable practices and mitigating environmental consequences.