Cradle-to-Grave Life-Cycle Assessment of Cellulosic Fiberboard

Abstract

According to the United Nations Environment Programme (UNEP), the construction and operation of buildings accounted for nearly 38% of total global energy-related CO₂ emissions in 2019. The construction sector has been striving to use more low-carbon footprint building products to mitigate climate change and enhance environmentally preferable purchasing. Over the last several decades, there has been substantial growth in engineered wood products for the construction industry. To assess these products used in construction for their environmental profile, lifecycle assessments (LCAs) are performed. This study performed an LCA to estimate environmental impacts (cradle-to-gate and gate-to-grave) of cellulosic fiberboard (CFB) per m³ functional unit basis. The lifecycle inventory data developed were representative of CFB production in North America. Overall, the cradle-to-grave LCA results per m3 of CFB were estimated at 305 kg CO₂ e global warming (GW), 19.3 kg O₃ e photochemical smog formation, 1.03 kg SO₂ e acidification, 0.33 kg N e eutrophication, and 415 MJ fossil-fuel depletion. Except for smog formation, most environmental impacts of CFB were from cradle-to-gate. For example, 71% and 29% of total GW impacts were from cradle-to-gate and gate-to-grave lifecycle stages, respectively. The sensitivity analysis showed that reducing transport distance, on-site electricity use, natural gas for drying, and starch additives in the manufacturing phase had the most influence. Around 353 kg CO₂ e/m³ of CFB is stored as long-term carbon during CFB’s life which is higher than the total cradle-to-grave greenhouse gases (CO₂ e) emissions. Thus, the net negative GW impact of CFB (-47 kg CO₂ e/m³ of CFB) asserted its environmental advantages as an engineered wood panel construction material. Overall, the findings of the presented study would prove useful for improving the decision-making in the construction sector.