Poiseuille Flow in a Vertical Tubular and Porous Membrane for Solar Air Gap Membrane Desalination of Brackish Water

摘要

Membrane distillation is an emerging technology for desalination that differs from other membrane technologies and in which the driving force for desalination is the difference in vapor pressure of water across the membrane, rather than total pressure. The membrane is hydrophobic material that allows water vapor only to pass across. The vapor pressure gradient is created by heating the source water, thereby elevating its vapor pressure. The major energy requirement is for low-grade solar energy. The technique used to desalinate water is the Air Gap Membrane Distillation (AGMD), which is more compact, less energy-consuming and required lower temperature (between 40 °C to 80 °C) than conventional distillation processes. In this paper, the work aims to establish a mathematical model of the Navier-Stockes equation applied to a porous membrane of polytetrafluoroethylene. PTFE nanofiber membrane could be used in membrane distillation to produce drinking water from a saline water of NaCl.