Assessing the Environmental Sustainability of Lignin-Based Epoxy Resins for Coating Production

The coating industry's desire to actively participate in green transmission has led to numerous initiatives. One such initiative explores lignin as a potential substitute for fossil hydrocarbons, currently used in the industry. However, before committing substantial resources to its development, it is crucial to determine whether this path is truly more sustainable. In this work, lignin is used as a hydrocarbon source to manufacture epoxy resins for protective-coating production, and Life Cycle Assessment (LCA) is employed to compare its environmental sustainability with the standard fossil-based epoxy resin. The results offer mixed signals, depending on the industry's priority, which currently centers on carbon-emission reduction. In this regard, lignin-based epoxy resin, despite its early development stage, shows promise as a greener alternative. However, there is a risk of problem shifting from climate change to other environmental issues. Impact categories, such as human toxicity and ecotoxicity from the emission of toxic substances, eutrophication, and particle emissions, do not currently favor lignin epoxy resin due to limitations in existing technology. Nevertheless, further development and optimization could position lignin epoxy resin as a sustainable choice across a broader spectrum of environmental concerns in the future. The study also underscores issues with chemical LCA databases, notably their incompleteness and challenges in updating, particularly in assessing toxic effects.