Enabling High-Boiling-Point Green Solvent Recycling Using Organic Solvent Nanofiltration Membranes.

The extensive use of organic solvents in industrial processes contributes to environmental pollution, resource depletion, and human health hazards, incentivizing the development of more sustainable alternatives. In response, bio-based "green" solvents have emerged as environmentally benign substitutes, offering reduced toxicity and lower carbon footprints. However, their industrial implementation is challenged by high viscosity, energy-intensive recovery, and limited life-cycle sustainability when employed in single-use processes. Herein, organic solvent nanofiltration (OSN) as an energy-efficient and selective membrane-based technology for recycling green solvents is explored. OSN membranes enable solvent purification by selectively removing impurities while preserving solvent integrity, reducing waste generation and energy consumption. OSN performance in the recovery of widely used green solvents, including acetone, acetonitrile, ethyl acetate, Cyrene, dimethyl isosorbide (DMI), and γ-valerolactone (GVL), is evaluated. The potential of OSN for in-process solvent recycling is demonstrated, with a case study on the recycling of Cyrene in synthetic leather production, demonstrating the feasibility of OSN membranes in maintaining solvent purity and enabling a more sustainable manufacturing process.