(44f) Comparative Analysis of Six Commercially Available Organic Solvent Nanofiltration Membranes for Hydrocarbon Separations

Membrane technology, specifically organic solvent nanofiltration (OSN), presents an alternative to distillation with potential reductions in energy, carbon, and physical footprint. OSN is driven by a pressure differential, which requires less energy than that required for a phase change. This potential has generated substantial interest in the oil refining, chemical, and bioprocessing industries. These applications require solvent-resistant membranes that preserve separation characteristics while processing a large range of solvents. This work investigates the separation performance of six commercial OSN membranes for hydrocarbon mixtures, using a nine-component blend under various operating pressures. Key performance metrics including membrane permeance and selectivity will be presented. Among the membranes evaluated, the Evonik Puramem Performance membrane provides the lowest permeance (0.81 LMHB), whereas the Borsig oNF-3 membrane provides the greatest permeance (4.59 LMHB). For all membranes, components with a molecular weight of <120 g/mol were concentrated in the permeate, while components with a molecular weight of >200 g/mol were concentrated in the retentate, with the Borsig oNF-1 and Evonik Puramem Performance showing better selectivity relative to the other membranes. In addition to membrane performance, scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared (FTIR) spectroscopy, and contact angle measurements were used to characterize the membrane surface morphology and topology, chemical composition, and hydrophilicity/hydrophobicity. Results indicate that these membranes are composed of silicone polymer-based active layers, all of which are hydrophobic (contact angles >90°). Overall, this comparative analysis provides a foundation for comprehensive dataset for OSN process simulation and future OSN development and improvement efforts.