Understanding the environmental impacts of large-scale cellulose nanocrystals production: Case studies in regions dependent on renewable and fossil fuel energy sources

Favorable functional properties of cellulose nanocrystals (CNCs) in several end-use application areas, as well as its ‘green’ credential as a bio-based material stimulate significant interest in scaling up the manufacture of CNCs. As in any other process, there exist several design options for the overall process and decisions on adoption of a specific plant configuration should be based on economic as well as environmental data, preferably from the life cycle assessment perspective. In this study we establish a benchmark LCA study of a conceptual large-scale CNC manufacturing process based on sulfuric acid hydrolysis. We then use the benchmark process model to explore several plant configuration scenarios and sensitivity of optimal plant configurations to energy mix of different regions. Results of LCA study suggest the optimal plant configuration to include partial recycle of sulfuric acid, which allows to attain the minimum cradle-to-gate environmental impacts. This study provides benchmark figures of LCA impacts of CNC manufacture, which could be used for the assessment of carbon footprint and other environmental metrics of final products manufactured from CNCs.