A novel high-packing-density plate-and-frame membrane module integrated with ZIF-8/PMPS mixed matrix membranes for efficient butanol recovery from dilute solutions

This study addresses the challenges of bio-butanol recovery by synergizing innovative module design with advanced mixed matrix membranes (MMMs) for enhanced pervaporation (PV) efficiency. ZIF-8 nanoparticles (14–120 nm) were integrated into a polymethylphenylsiloxane (PMPS) matrix to fabricate ZIF-8/PMPS MMMs on flat-sheet Al₂O₃ supports, for efficient n-butanol separation via pervaporation. The optimized 14 nm-ZIF-8/PMPS MMMs (13.0 wt% loading) exhibited optimal performance, achieving a total flux of 925.86 g m⁻² h⁻¹ and a separation factor of 37.65 for 1 wt% n-butanol/water mixtures at 40 °C, enabling stable operation over 600 h. Key factors included the improved hydrophobicity, reduced interfacial voids, and enhanced surface roughness. A novel plate-and-frame module was engineered to address scalability challenges, increasing packing density from 5 to 55 m²/m³ while mitigating concentration polarization and enhancing mass transfer under dynamic flow conditions. The module's compact design, combined with the mechanical robustness of Al₂O₃ supports and the compatibility of ZIF-8/PMPS membranes, demonstrates industrial viability.