Assessment of the Efficiency and Economic Viability of an Upgraded Vacuum Membrane Distillation Setup for Ethanol-Water Separation

Abstract

Membrane distillation is a promising technique for extracting organic molecules from water mixtures. It works by applying pressure and heat differentials across hydrophobic microporous membranes. This work uses pre-prepared Polyvinylidene fluoride membranes to explore vacuum membrane distillation (VMD) at both laboratory and pilot scales. Ethanol-water solutions with different ethanol concentrations (2%, 5%, 7%, and 10%), temperatures (293 K to 333 K), and feed flow rates (0.06 to 0.18 L/s) are used to assess the system's performance. The separation factor ranges from 4 to 9.6, and at 328 K, 10 weight percent ethanol, and a feed flow rate of 0.18 L/min, a maximum total membrane flux of 44 kg/m²hr is attained. To ascertain whether VMD for ethanol-water separation is economically feasible, cost indicators are also evaluated. Based on a preliminary assessment using a 174 L/day pilot unit, it is possible that capital and operational costs will decrease as the technology develops and is scaled up, especially if low-grade energy sources are used.