Development of asymmetric membranes modified with ionic liquids for the recovery of aromas and fragrances from model agricultural residues to be used in pervaporation processes

This study focuses on the development of asymmetric multilayer membranes modified with ionic liquids for the recovery of aromas and fragrances (AF) from model agricultural waste streams through pervaporation. The membranes were prepared using hydrophobic polymers PEBA and POMS combined with two ionic liquids: [Bmim][Tf2N] and [P1444][Tf2N], stabilized through gelation with 12-hydroxystearic acid. The research evaluated membrane preparation, extraction capacity, transmembrane flux, selectivity, and mass transfer resistance. Results showed that the membrane PEBA/[Bmim][Tf2N]/PEBA exhibited the highest extraction rates and lowest mass transfer resistance for key aroma compounds such as hexanal and linalool. The choice of ionic liquid significantly influenced the membrane's affinity towards different compounds: [Bmim][Tf2N] favored polar compounds, while [P1444][Tf2N] enhanced transport of hydrophobic ones. Membranes containing ionic liquids showed improved selectivity toward aroma compounds over water, outperforming single-layer membranes. These findings confirm that the integration of ionic liquids into polymeric membranes enhances the efficiency of pervaporation for aroma recovery. This approach offers a sustainable and high-value solution for the valorization of agro-industrial residues, with promising applications in the cosmetics industry. The study supports the development of environmentally friendly separation processes aligned with circular economy principles.