membrane distillation

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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.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

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

McGraw-Hill Concise Encyclopedia of Engineering. © 2002 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Fell, "Heat and mass transfer in membrane distillation," Journal of Membrane Science, vol.
Alkhudhiri et al., "Membrane distillation: a comprehensive review," Desalination, vol.
As per Memsys, it is the world's first desalination unit utilising the waste heat of the local power generator to produce up to 10 tons of drinking water per day through membrane distillation.
memsys' robust technology is based on vacuum-driven multi-effect membrane distillation (V-MEMD), a highly efficient thermal separation process in a compact, modular concept.
Matsuura, "Preparation and characterization of novel hydrophobic/hydrophilic polyetherimide composite membranes for desalination by direct contact membrane distillation, " Journal of Membrane Science, vol.
Guddad, "Reverse osmosis and membrane distillation for desalination of groundwater: a review," ISRN Materials Science, vol.
The same problem affects membrane distillation based processes [23].
Among the topics are supercritical fluid extraction, ion exchange, membrane distillation, extraction-fermentation hybrid, separating and purifying lignocellulose hydrolyzates, and extracting algae oil from microalgae.
"Any new leading-edge technologies that have emerged in the past five years will be considered for the pilot plants, including electrolysis deionisation and membrane distillation," he explained.
Mohamed Khayet Souhaimi from University Complutense of Madrid for his work in promoting membrane distillation for water recovery using alternative renewable energy sources.

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