Flux Enhancement in Hybrid Pervaporation Membranes Filled with Mixed Magnetic Chromites ZnCr2Se4, CdCr2Se4 and CuCr2Se4.

The integration of bioethanol into transportation fuels requires efficient purification methods to overcome the ethanol-water azeotrope, which cannot be separated by conventional distillation. Pervaporation has become an attractive alternative, offering high selectivity while minimising energy consumption. To further improve membrane performance, this study analyses sodium alginate-based hybrid membranes containing binary mixtures of chromite selenides with varying magnetic properties (ZnCr2Se4, CdCr2Se4, and CuCr2Se4). Pairwise combinations of these fillers were introduced to create complex magnetic structures that can influence polymer-filler interactions and molecular transport. Structural, magnetic, and functional characterisation showed that membrane properties were strongly dependent on the type and proportion of fillers. In particular, the CdCr2Se4 with CuCr2Se4 combination exhibited the most favourable balance between permeation flux and selectivity, achieving the highest parameters, including pervaporation separation index (PSI) reaching 747 kg·m-2·h-1. This superior performance is attributed to the synergistic interaction of these two magnetic fillers, which enhances membrane selectivity while maintaining its integrity. This work presents a novel approach to membrane-based separation, advancing the development of energy-efficient, environmentally sustainable bioethanol purification technologies.