Life Cycle Assessment of Polyol Production from Lignin via Organosolv and Liquefaction Treatments

Abstract

This study aimed to conduct a comprehensive Life Cycle Assessment (LCA) of lignin-based polyol production through organosolv fractionation of cardoon stalks and subsequent lignin liquefaction. The LCA employed a cradle-to-gate approach, encompassing cardoon cultivation and all processing steps leading to polyol production. The research involved laboratory-scale optimization of the organosolv and liquefaction processes, followed by industrial-scale implementation. The analysis revealed that all stages of the production chain, including crop cultivation, organosolv, and liquefaction, significantly influenced overall environmental impacts. Specific materials and processes played pivotal roles, such as harvesting machinery and fertilizers in crop production, γ-Valerolactone (GVL) as the primary contributor (72–100%) to environmental impacts in the organosolv phase, and materials like polyethylene glycol 400 (PEG 400) and glycerin in the liquefaction phase, accounting for the majority (96–100%) of environmental impacts in this stage. When considering endpoint damage categories, it became evident that this production chain had a notable impact on human health, primarily due to emissions in air, water, and soil from agricultural processes. Lignin-based polyols demonstrated a moderate improvement compared to their petroleum-based counterparts, with an approximate reduction of 3–16% in environmental impact.