membrane distillation

Also found in: Acronyms.

membrane distillation

[′mem‚brān ‚dis·tə′lā·shən]
(chemical engineering)
A separation method that uses a nonwetting, microporous membrane, with a liquid feed phase on one side and a condensing permeate phase on the other. Also known as membrane evaporation; thermopervaporation; transmembrane distillation.

Membrane distillation

A separation method in which a nonwetting, microporous membrane is used with a liquid feed phase on one side of the membrane and a condensing, permeate phase on the other side. Separation by membrane distillation is based on the relative volatility of various components in the feed solution. The driving force for transport is the partial pressure difference across the membrane. Separation occurs when vapor from components of higher volatility passes through the membrane pores by a convective or diffusive mechanism. See Convection (heat)

Membrane distillation shares some characteristics with another membrane-based separation known as pervaporation, but there also are some vital differences. Both methods involve direct contact of the membrane with a liquid feed and evaporation of the permeating components. However, while membrane distillation uses porous membranes, pervaporation uses nonporous membranes.

Membrane distillation systems can be classified broadly into two categories: direct-contact distillation and gas-gap distillation. These terms refer to the permeate or condensing side of the membrane; in both cases the feed is in direct contact with the membrane. In direct-contact membrane distillation, both sides of the membrane contact a liquid phase; the liquid on the permeate side is used as the condensing medium for the vapors leaving the hot feed solution. In gas-gap membrane distillation, the condensed permeate is not in direct contact with the membrane.

Potential advantages of membrane distillation over traditional evaporation processes include operation at ambient pressures and lower temperatures as well as ease of process scale-up. See Membrane separations

References in periodicals archive ?
The schematic process of the vacuum membrane distillation was illustrated in our previous work [37].
A predictive model for the assessment of the temperature polarization effect in direct contact membrane distillation desalination of high salinity feed.
It is part of an agreement signed in October 2011 between Qatar University and the Global Water Sustainability Centre, aimed at helping the university to build capacity in research in membrane distillation.
LANI ROSE R DIZON DOHA THE pilot phase for the Membrane Distillation (MD) project between ConocoPhillips and Qatar University's Chemical Engineering Department was inaugurated on Wednesday.
The company's PTFE hollow fiber membranes find uses for filtration, ozone applications, membrane distillation and desalination and degassing.
Summary: TEHRAN (FNA)- Scientists managed to develop a faster, better and cheaper desalination process enhanced by carbon nanotubes which creates a unique new architecture for the membrane distillation process by immobilizing carbon nanotubes in the membrane pores.
1997) investigated experimentally the permeation flux of water vapor in membrane distillation of an aqueous lithium bromide solution.
This paper describes the investigation on the treatment of oily wastewater by ultrafiltration (UF) followed by membrane distillation (MD) as a final treatment process.
The shortlisted entries were presented under the categories of desalination and renewables, desalination and energy, novel processes, membrane distillation, forward osmosis, novel membranes, and fouling, as well as a special GCC-Korea session.
These include forward osmosis, membrane distillation, tri-hybrid applications using nanofiltration, and low temperature distillation.

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