Jeong F. Kim

Conventional chemical recycling of polyethylene terephthalate (PET) via glycolysis is hindered by the high energy cost of separating water and ethylene glycol (EG) via distillation. In this work, the energy‐intensive EG‐water separation step was excluded by implementing a water‐free, membrane‐based process for the production and purification of bis(2‐hydroxyethyl) terephthalate (BHET) from PET glycolysis. The proposed approach is built upon three key innovations: (1) a micro‐sized MgO/SiO ₂ heterogeneous catalyst that enhances PET depolymerization efficiency, achieving a 95.1% BHET yield, (2) a water‐free glycolysis process that reduces process complexity, and (3) an organic solvent nanofiltration‐based purification and concentration strategy that selectively separates BHET while minimizing energy‐intensive phase‐change operations. A high overall BHET yield of 93.2% was achieved, enabled by a two‐stage cascade concentration with over 99% yield. Compared to conventional distillation, the proposed process reduces energy consumption by 86%. Techno‐economic analysis revealed a return on investment of 2.48 years for a production capacity of 1000 tons of BHET per day, highlighting its economic viability. By minimizing reliance on phase‐change operations, this process presents a scalable and transformative solution for sustainable chemical recycling, serving as an important stepping stone to transform PET glycolysis from a batch to a continuous process.

High-performance and durable anion exchange membranes (AEMs) are critical for realizing economical green hydrogen production through alkaline water electrolysis (AWE) or AEM water electrosysis (AEMWE). However, existing AEMs require sophisticated fabrication protocols and exhibit unsatisfactory electrochemical performance and long-term durability. Here we report an AEM fabricated via a one-pot, in situ interfacial Menshutkin reaction, which assembles a highly cross-linked polymer containing high-density quaternary ammoniums and nanovoids inside a reinforcing porous support. This structure endows the membrane with high anion-conducting ability, water uptake (but low swelling), and mechanical and thermochemical robustness. Consequently, the assembled membrane achieves excellent AWE (0.97 A cm^-2 at 1.8 V) and AEMWE (5.23 A cm^-2 at 1.8 V) performance at 5 wt % KOH and 80 °C, significantly exceeding that of commercial and previously developed membranes, and excellent long-term durability. Our approach provides an effective method for fabricating AEMs for various energy and environmental applications.