17/10/2024
EcoSolventCycle: Membrane based process for water treatment of recyclable solvents
Despite the industry’s shift toward eco-friendly technologies, membrane manufacturing still relies on toxic solvents like DMAC, DMF, and NMP, which harm the environment and are difficult to biodegrade. The European Union’s classification of NMP as a high-concern substance has increased the urgency to find safer alternatives. Green solvents such as DMSO and Cyrene® show promise as replacements, but fully sustainable processes also require recycling these solvents to reduce pollution and costs, as membrane manufacturing generates wastewater filled with contaminants.
The EcoSolventCycle project aims to improve sustainability by exploring the feasibility of recycling process water and separating solvents and polymeric additives from wastewater using membrane technology. This approach is more energy-efficient than traditional thermal separation methods, which consume 80% of industrial energy. Various membrane processes, including ultrafiltration (UF), nanofiltration (NF), organic solvent nanofiltration (OSN), pervaporation (PV), and membrane distillation (MD), will be studied.
Initial results showed that UF membranes could remove over 99% of PVP from wastewater, and PV or MD could recycle over 90% of the process water with high NMP and glycerol rejection. Solvent extraction recovered more than 75% of NMP with a purity of 98.5%. An economic analysis indicated that MD-based processes significantly reduced costs compared to full distillation methods.
