Environmental Impacts of Polylactic Acid Synthesis via Diverse Biorefinery Strategies: Progressive Analysis Based on Dynamic Lifecycle Assessment

Polylactic acid (PLA), with its remarkable characteristics and excellent biodegradability, has raised intensive research on production feedstock and synthesis techniques. However, most of this research remains limited to the laboratory scale due to uncertainties regarding feasibility and environmental impacts. In this study, a progressive analysis framework was established to evaluate the environmental impacts of PLA synthesis through a dynamic lifecycle assessment. Three successive traversals were conducted, focusing on feedstock selection, lactic acid extraction, and catalytic polymerization. Based on the lifecycle assessment results, the optimal strategy was identified as using food waste as feedstock to generate PLA through the ethyl acetate extraction of lactic acid and zinc oxide nanoparticle catalytic ring-opening polymerization, which demonstrated more favorable potential environmental impacts. The impacts were reduced by 42-56%, including 42% in global warming potential, 44% in acidification potential, and 56% in water usage. The consumption of steam, sodium hydroxide, and electricity was identified as primary contributors via cumulative contribution analysis. Potential improvement opportunities were discussed accordingly. The study outcomes provide practical recommendations for PLA bioproduction toward sustainable and industrial development. © 2025 American Chemical Society.