A membrane distillation device, provided with a membrane distillation module including a plurality of hydrophobic porous hollow fiber membranes, and a condenser for condensing water vapor extracted from the module. The average pore diameter of the porous hollow fiber is 0.01-1 μm. The filling ratio of the porous hollow fiber of the membrane distillation module is 10-80%, and the pressure condition for the membrane distillation is equal to or greater than 1 kPa and equal to or less than the saturated vapor pressure of water at the temperature of the water being treated.

Various examples are provided that are related to boundary control in membrane distillation (MD) processes. In one example, a system includes a membrane distillation (MD) process comprising a feed side and a permeate side separated by a membrane boundary layer; and processing circuitry configured to control a water production rate of the MD process based at least in part upon a distributed heat transfer across the membrane boundary layer. In another example, a method includes determining a plurality of estimated temperature states of a membrane boundary layer separating a feed side and a permeate side of a membrane distillation (MD) process; and adjusting inlet flow rate or inlet temperature of at least one of the feed side or the permeate side to maintain a difference temperature along the membrane boundary layer about a defined reference temperature based at least in part upon the plurality of estimated temperature states.

A distillation device and method of manufacturing a distillation device is disclosed. The distillation device includes at least one spiral wound membrane distillation (MD) unit. The spiral wound MD unit includes a perforated center tube concentric to a cylindrical housing and a plurality of effects spirally wound around the center tube. Each of the effects include a vapor permeable membrane, a feed spacer disposed on the vapor permeable membrane, a permeate spacer, and a heat exchange film. The permeate spacer is disposed between the vapor permeable membrane and the heat exchange film. Distillation of a feed fluid by the plurality of effects deposits a condensate fluid into the center tube.

A desalination system, including a membrane distillation portion, a solar power concentration portion, and a thermal vapor compression portion operationally connected to the membrane distillation portion and to the solar power concentration portion. The membrane distillation portion includes a first vessel having a first portion and a second portion separated by a hydrophobic membrane operationally connected therebetween and oriented to pass water from the first portion to the second portion, wherein the hydrophobic membrane further comprises a hydrophilic membrane and an air blocking layer connected to the hydrophilic membrane and disposed in the first portion, a vacuum gap adjacent the hydrophobic membrane and disposed in the second portion, a first fluid inlet and a first fluid outlet operationally connected to the first portion, and a second fluid inlet and a second fluid outlet operationally connected to the second portion. The solar power concentration portion includes a pump having a pump outlet and a pump inlet operationally connected to a water line and to the vacuum gap, a linear Fresnel mirror collector for collecting and focusing sunlight, and an outlet line operationally connected to the pump outlet and positioned to receive focused sunlight from linear Fresnel mirror collector. The thermal vapor compression portion includes an ejector having an ejector inlet portion and an ejector outlet portion, wherein the ejector inlet portion is operationally connected to the outlet line and to the vacuum gap, a second vessel fluidically connected to the outlet portion and further including a heat exchanger operationally connected to the ejector outlet portion and to a water pipe, a feed spray operationally connected to the second outlet and positioned to spray into the heat exchanger, and a collection portion for receiving concentrated feed spray. The heat exchanger receives desalinated water from the ejector and from the feed spray. The water line carries desalinated water from the heat exchanger. The first outlet passes concentrated brine, and the first inlet receives feed water to be desalinated.

A novel method of producing concentrated streams or otherwise useful hypersaline brines from a source of non-potable or otherwise impaired water is provided. The method comprises feeding the source water into the feed side of a membrane distillation unit while simultaneously feeding a distillate stream through the receiving side of the distillation unit. The feed and receiving sides are separated by a hydrophobic, microporous membrane that allows water vapor to flux through the membrane to the receiving side. As the membrane becomes clogged with particulates, the unit can be subjected to stream flow reversal and/or temperature gradient reversal in order to remove those particulates and restore previous vapor flux levels, after which previous operations can be resumed.

In some embodiments, the present disclosure pertains to systems and methods for distilling a fluid by exposing the fluid to a porous membrane that includes a surface capable of generating heat. In some embodiments, the heat generated at the surface propagates the distilling of the fluid by converting the fluid to a vapor that flows through the porous membrane and condenses to a distillate. In some embodiments, the surface capable of generating heat is associated with a photo-thermal composition that generates the heat at the surface by converting light energy from a light source to thermal energy. In some embodiments, the photo-thermal composition includes, without limitation, noble metals, semiconducting materials, dielectric materials, carbon-based materials, composite materials, nanocomposite materials, nanoparticles, hydrophilic materials, polymers, fibers, meshes, fiber meshes, hydrogels, hydrogel meshes, nanomaterials, and combinations thereof. Further embodiments pertain to methods of making the porous membranes of the present disclosure.

A membrane wettability system including a power source configured to generate a current; a measuring device configured to measure the current; a first conducting spacer that is electrically connected to one of the measuring device and the power source; and a second conducting spacer that is electrically connected to another one of the measuring device and the power source. The first conducting spacer is physically separated from the second conducting spacer by a membrane, which is not conducting the current.

A technique to desalinate seawater using melanin-concentrated solar energy wherein the melanin is extracted from a local isolate Aspergillus niger. A device consists of two fixed upper and lower containers with same volume of seawater in both, with or without melanin powder dissolved in the lower container at rate of 0.17 gm of melanin powder per 10 ml of water. The device is put outdoors under direct sunlight during daytime, circular water droplets free of salt starts to appear on the external bottom of upper container. Water droplets are collected by a sterile glass rod, pH of droplets water is about 7.1. Yield of fresh water is approximately 10 ml droplets water from 600 ml seawater per hour; after 24 hours day and night incubation, seawater in the upper container dries out leaving salt crystals. Yield of 1000 m3 seawater is 100 m3 freshwater (1000 L seawater yield 100 L freshwater).

A membrane distillation apparatus includes a housing and an impeller. The housing includes a hot medium compartment, a cold medium compartment, an air gap compartment, a membrane, and a thermally conductive plate. The hot medium compartment includes a hot medium inlet configured to receive a hot medium stream including water. The cold medium compartment includes a cold medium inlet configured to receive a cold medium stream. The membrane defines pores that are sized to allow water vapor originating from the hot medium stream to pass from the hot medium compartment through the membrane to the air gap compartment. The thermally conductive plate and the cold medium stream are cooperatively configured to condense the water vapor from the hot medium stream. The air gap compartment is substantially filled with air and includes a permeate outlet configured to discharge the condensed water vapor. The impeller is disposed within the air gap compartment.

A membrane distillation apparatus includes a housing and an impeller. The housing includes a hot medium compartment, a cold medium compartment, a permeate gap compartment, a membrane, and a thermally conductive plate. The hot medium compartment includes a hot medium inlet configured to receive a hot medium stream including water. The cold medium compartment includes a cold medium inlet configured to receive a cold medium stream. The membrane defines pores that are sized to allow water vapor originating from the hot medium stream to pass from the hot medium compartment through the membrane to the permeate gap compartment. The thermally conductive plate and the cold medium stream are cooperatively configured to condense the water vapor from the hot medium stream. The permeate gap compartment includes a permeate outlet configured to discharge the condensed water vapor. The impeller is disposed within the permeate gap compartment.