Decision-Relevant Sustainability Assessment of Lignin-Derived Structured Carbons for Scalable CO ₂ Capture

Bio-based sorbents derived from lignin have the potential to reduce the climate impact of CO 2 capture relative to conventional coal-based activated carbons, yet their large-scale feasibility remains uncertain. Here, we present a decision-oriented sustainability assessment of activated lignin supraparticles, structured carbon sorbents assembled from lignin and fibrillated cellulose, using an integrated framework combining industrial-scale process design, techno-economic analysis (TEA), and life-cycle assessment (LCA). A continuous production process handling 100,000 t year − 1 of kraft lignin was designed and simulated using detailed mass and energy balances, equipment sizing, and heat integration. Under financial assumptions including a 12.1% hurdle rate and a 20-year plant lifetime, the baseline minimum product selling price was estimated at 5.3 USD/kg. Sensitivity analysis indicates that this value could decrease to 3.5 USD/kg under favorable conditions, with product yield, lignin feedstock cost, wet solid concentration prior to drying, and capital intensity identified as the primary economic drivers. From a climate perspective, activated lignin supraparticles exhibit a cradle-to-gate global warming potential of 1.94 kg CO 2 -eq kg − 1 under standard biogenic carbon accounting assumptions, substantially lower than reported values for coal-based activated carbon, while offering comparable CO 2 adsorption capacity. By explicitly linking process design choices with economic performance and life-cycle climate impacts, this study provides a quantitative framework to guide the deployment of lignin-derived structured carbons as sustainable adsorbents in carbon capture value chains.