Effect of Teflon-Coated PVDF Membrane on the Performance of a Solar-Powered Direct Contact Membrane Distillation System

Abstract

The present study dealt with the generation of freshwater through the direct contact membrane distillation (DCMD) technique, powered by an evacuated tube solar collector (ETSC). The major objective of the present work was to determine the optimum conditions of fluid flow rate and temperature for maximum freshwater productivity across both the feed and permeate sides of the membrane module. A flat hydrophobic membrane composed of polyvinylidene fluoride (PVDF) coated with Teflon was utilized for the DCMD process. The rate of freshwater production was examined with the variation in the feed/permeate flow rates (from 3 to 7 LPM) and feed temperature (from 45 °C to 75 °C) for a constant permeate-side temperature of 30 °C. The experimental results indicated that a maximum freshwater productivity of 45.18 kg/m2h was achievable from the proposed system during its operation with a high solar heated inlet feed temperature of 75 °C and mass flow rates of 7 LPM across both sides of the membrane. Further, a detailed assessment of the performance parameters indicated that the present solar-powered DCMD system exhibited a maximum evaporative efficiency of about 80% and temperature polarization coefficient (TPC) of 0.62 respectively.

Modeling and simulation of direct contact membrane distillation system integrated with a photovoltaic thermal for electricity and freshwater production

“…The developed DCMD system produces drinkable water at 45.18 kg per square meter per hour using an evacuated tube solar collector. Solar heating at 75 °C maintained a mass flow rate of 7 L/min on both sides of the membrane and 80% evaporation efficiency (CK et al, 2022). Previously conducted studies did not provide complete simulations of solar energy integrated with DCMD systems that allowed optimization of a small-scale saline solar desalination, which could be useful for DCMD solar installations that produce drinking water.…”