Green & Sustainable Membranes for Efficient Bioethanol Purification via Pervaporation

Abstract

Traditional membrane technologies, typically reliant on fossil-based polymers and hazardous solvents, pose significant environmental threats. To address these challenges, this study introduces an innovative approach: the development of hydrophobic mixed matrix membranes utilizing waste polyvinyl chloride (PVC) pipes and deep eutectic solvents (DES) based on thymol: urea as green additives. The research focuses on synthesizing two types of membranes: dense and asymmetrical. Each type is evaluated for its efficiency in terms of flux and selectivity. The asymmetric membranes undergo optimization processes, involving adjustments in polymer concentration, co-solvent use, and evaporation time, to enhance pervaporation performance. This optimization aims to achieve maximum ethanol flux and high separation factor. In contrast, the dense recycled PVC membranes exhibit comparable results to conventional polymeric membranes in terms of flux (1.98 kg/m2) and separation factor (16). Significantly, the incorporation of DES into the membrane matrix results in substantial performance improvements. The separation factor enhanced by approximately 125%, alongside a 36% increase in ethanol sorption capacity. Asymmetric membranes particularly demonstrate a higher potential in flux performance, reaching 5.12 kg/m2.hr, in contrast to dense membranes with a flux of 1.98 kg/m2.hr. These findings highlight the effectiveness of using recycled waste materials and DES in membrane fabrication. This approach not only enhances pervaporation performance but also aligns with the goals of green and sustainable membrane technology, offering a promising solution to environmental concerns in the field of membrane separation.