Integrated techno-economic and environmental assessment of pretreatment strategies for cotton-polyester textile waste valorization in Europe.

This study presents an integrated techno-economic and life cycle assessment (LCA) of a biorefinery for the valorization of cotton-polyester textile waste (50/50 wt%) into LA, TPA, and EG under three pretreatment strategies: alkaline (Na2CO3), organosolv (NMMO), and acidic (H3PO4). The system processes 72,000 t/y of post-consumer textiles and is modelled using Aspen Plus and Aspen PEA for process simulation and economic evaluation, and SimaPro with ReCiPe 2016 for environmental assessment in accordance with ISO 14040/14044 standards. Results indicate that pretreatment selection significantly affects process performance. The alkaline route achieves the lowest total capital investment (133.60 M$), highest internal rate of return (29.1 %), and shortest payback period (3.34 years). The organosolv route produces the highest LA output (18,145 t/y), while the acidic route yields the highest TPA (25,715 t/y) and EG (8,214 t/y), but also the highest capital (202.34 M$) and operating costs (35.28 M$/y). The midpoint LCA results showed that the alkaline pathway generally had the lowest environmental impacts across most categories, although category-specific trade-offs were observed. The endpoint single scores were 50.07, 77.38, and 104.35 mPt/FU for LA; 40.69, 62.87, and 84.76 mPt/FU for TPA; and 29.43, 45.47, and 61.31 mPt/FU for EG for the alkaline, organosolv, and acidic pathways, respectively. Compared with conventional production, the evaluated pathways generally showed lower environmental burdens, although this advantage varied among products and pretreatment routes. Overall, the alkaline pathway demonstrated the most favorable environmental performance among the evaluated strategies.