Life Cycle Sustainability Assessment of Fossil- and Bio-Based Membrane Manufacturing
The transition towards sustainable membrane manufacturing is challenged by its reliance on fossil-based polymers, organic solvents, and generation of large volumes of contaminated water. We combined process simulation, life cycle assessment, and Monte Carlo simulation to identify hotspots in the manufacturing of ultrafiltration hollow-fiber membranes for pharmaceutical applications and evaluate strategies to mitigate impact and reduce waste generation. Process models informed by industry input compared fossil- and bio-based membranes on a cradle-to-gate basis per square meter of membrane produced. Key environmental hotspots include polymer and bore solution preparation, driven by the contribution of polymer and solvent, accounting for 30-80% of total impacts across the categories investigated, and wastewater dilution, driven by the environmental burden of solvent-contaminated wastewater management. Under the modeled conditions, although polymer substitution can reduce environmental burdens, cellulose-based membranes show higher impacts than polysulfone membranes in at least 85% of simulations within each impact category, due to chemical-intensive cellulose modification and regeneration. In contrast, solvent recycling can mitigate solvent- and wastewater-related burdens when combined with reduced water demand, yielding climate change benefits at water demands below approximately 36 L per m2 under the modeled recovery configuration and highlighting its potential to reduce the environmental footprint of membrane manufacturing.