Life Cycle Greenhouse Gas Emissions of Acetylated Cellulose Nanofiber-Reinforced Polylactic Acid Based on Scale-Up from Lab-Scale Experiments

Abstract

This study deals with the possible range of life cycle greenhouse gas emissions (LC-GHG) from acetylated cellulose nanofiber-reinforced polylactic acid (AcCNF/PLA) production processes, considering future scaling-up, process improvement, and variations in their process modeling and simulation. The chemical and mechanical processes required for breaking down aggregated natural cellulose into nanofibers and kneading as cellulose nanofiber-reinforced plastic are under development in lab or pilot scale; to assess future environmental performance, we estimated process inventories in future possible industrial processes for prospective life cycle assessment. It was found that both the pulp acetylation process and the mechanical kneading process makes up a large percentage of LC-GHG from AcCNF/PLA production and can be reduced by process improvement in industrialization. Acetic anhydride consumption is dominant in pulp acetylation LC-GHG and can be significantly reduced by installing and optimizing distillation columns for the recovery of excess acetic anhydride and byproduct acetic acid. Power consumption in the mechanical kneading process can also be reduced by increasing the production rate up to industrial scale.