COMPARATIVE EVALUATION OF PERVAPORATION MEMBRANES FOR SUSTAINABLE INDUSTRIAL DMC DEHYDRATION: PROCESS PERFORMANCE AND SELECTION CRITERIA

Abstract

Revised: Solvent dehydration remains a critical unit operation in industrial purification, where membrane-based separations can offer an energy-efficient alternative to conventional distillation. This study presents a comparative evaluation of two commercial pervaporation membranes for the dehydration of an industrial dimethyl carbonate (DMC)/water feed obtained from a distillation-based process in Cycle 1. Performance was assessed under varying temperature and feed-composition conditions using total flux, separation factor, water permeability, membrane selectivity, pervaporation separation index, and Arrhenius-based transport parameters in Cycle 2. Among the membranes tested, PERVAP® 4100 showed the highest selectivity, reaching a separation factor of 2852 at 35 °C with 90 wt% DMC, whereas Plasma 2540 showed lower selectivity but higher water permeability under identical conditions. Temperature increased the permeation flux of both membranes, while higher DMC concentrations improved selectivity but reduced water flux. Characterization by FTIR, TGA, contact-angle analysis, and mechanical testing was used to relate membrane structure to separation performance. Intrinsic membrane performance parameters including water permeability (Pw), membrane selectivity (αmem), diffusivity (Dw), and activation energy of permeation (Ep) using the Arrhenius framework using both the commercial membranes are reported in our study. PERVAP 4100 showed much higher selectivity (separation factor of up to 2852 at 35 C 90 wt% DMC) than Plasma 2540 (132.85 under the same conditions), whilst Plasma 2540 was found to be more water permeable (Pw up to 1.64 × 10⁻¹² barrer). The results provide a comparative basis for selecting commercial membranes for industrial DMC dehydration and for designing more efficient solvent-purification workflows.