A dehumidifying and humidifying apparatus is provided. The dehumidifying and humidifying apparatus includes a first exchange part in which steam is exchanged between a first fluid and external air due to a difference between partial pressures of the first fluid and the external air, and a heat exchange unit configured to supply the first fluid having a first partial pressure to the first exchange part and receive the first fluid having a second partial pressure that is different from the first partial pressure from the first exchange part.

Systems and methods using membrane distillation are provided for desalinating water, for example for the production of potable water, to address freshwater requirements. In an aspect the systems and methods do not require applying an external heat source, or the energy cost of the heating source, to heat the feed stream to the membrane. In an aspect, the sensible heat present in surface seawater is used for the heat energy for the warm stream fed to the membrane, and deep seawater is used as the cold/coolant feed to the membrane to provide the needed temperature gradient or differential across the membrane.

This disclosure provides water processing apparatuses, systems, and methods for recovering purified water and concentrated brine from wastewater. The water processing apparatuses, systems, and methods utilize ionomer membrane technology to separate water vapor from volatiles of a wastewater stream. The wastewater stream is evaporated into a gas stream including water vapor and volatiles of the wastewater stream in an evaporation container. The gas stream is delivered to a water separation module spatially separated from and fluidly coupled to the evaporation container. The water vapor of the gas stream is separated out in the water separation module while the volatiles are rejected. The water vapor can be collected into purified water while concentrated brine from the wastewater stream is left behind in the evaporation container.

A multistage membrane distillation device includes a plurality of membrane distillation cells each having at least one membrane. Each membrane defines a feed space at one surface thereof and a vapor space at an opposite surface thereof, and is configured to allow a part of a feed flowing in the feed space to evaporate and pass through the membrane as a vapor phase into the vapor space where the vapor phase is condensed to a distillate including a volatile and condensable substance, and the non-evaporated feed to exit the feed space as a concentrated fluid. The device further includes a fluid connection for allowing the distillate from an i.sup.th cell to flow as a feed into the feed space of an (i+1).sup.th cell to produce a further distillate with a higher concentration of the volatile and condensable substance. The concentrated fluid from each cell is prevented from entering the feed space of other cells.

A hybrid photovoltaic panel-interfaced distillation with and without a hydrophobic microporous membrane distillation process is provided that is capable of utilizing solar waste heat to perform liquid distillation while co-generating solar electricity. Solar waste heat co-generated at a photovoltaic panel is effectively utilized by in situ distillation liquid as an immediate heat sink in thermo contact with the photovoltaic panel, thus providing beneficial cooling of the photovoltaic panel and co-making of distillation products while generating electricity with significant improvement on total-process solar energy utilization efficiency. Its enabled beneficial utilization of waste heat can provide a series of distillation-related products such as: freshwater, sea salts, distilled water, distilled ethanol, hot water, hot steam, saline/brine products, and brine photobiological cultures for production of advanced biofuels and bioproducts, in addition to solar electricity.

A membrane distillation (MD) system includes a sweep gas MD (SGMD) module and a knockout chamber. The MD module includes a feed inlet, a feed outlet, a condensing media inlet, and a condensing media outlet. The condensing media is sweep gas. The knockout chamber is positioned after the feed outlet. The knockout chamber includes a liquid inlet, a liquid outlet, and a vapor outlet. Direct gas phase stripping within the SGMD module leads to additional water evaporation at the knockout chamber and contributes to enhanced water or VOCs removal of the MD system.

A process for the regeneration of a membrane wall in a distillation apparatus, wherein a distillation apparatus having one or more evaporation and condensation stages is provided, each evaporation and condensation stage having at least one flow channel conducting a liquid, said flow channel being at least partially confined by a vapor-permeable and liquid-impermeable membrane wall, wherein vapor emerging from the liquid passes through the membrane wall. The liquid is removed from the at least one flow channel, wherein, after the removal of the liquid, the membrane wall is surrounded on both sides by a gas atmosphere, but is still wetted with liquid, and this liquid is removed by adjusting the gas atmosphere surrounding the membrane wall such that the partial pressure of the liquid in the gas atmosphere is lower than the vapor pressure of the liquid wetting the membrane wall.

Exemplary embodiments in desalination by direct contact membrane distillation present a cylindrical cross-flow module containing high-flux composite hydrophobic hollow fiber membranes. The present embodiments are directed to a model that has been developed to describe the observed water production rates of such devices in multiple brine feed introduction configurations. The model describes the observed water vapor production rates for different feed brine temperatures at various feed brine flow rates. The model flux predictions have been explored over a range of hollow fiber lengths to compare the present results with those obtained earlier from rectangular modules which had significantly shorter hollow fibers.

The present disclosure relates to a hybrid AD-DCMD desalination system, where two subsystems, such as AD and DCMD, are integrated synergistically to maximize freshwater production. The waste heat released from an AD condenser is used to drive the DCMD subsystem in a first configuration of the hybrid AD-DCMD system, while another configuration relies on the heat released due to an exothermic adsorption process in an adsorption bed. The DCMD subsystem is included to exploit the waste heat of the AD subsystem to enhance performance. In both these configurations, seawater is used to release the heat from the AD subsystem, which is then fed into the DCMD subsystem. The hybrid AD-DCMD system configurations demonstrate improved performance in terms of GOR, specific daily water production (SDWP), and freshwater cost reduction.

A system for treating high temperature produced water includes an electrocoagulation unit, a membrane distillation unit in communication with the outlet of the electrocoagulation unit having a hydrophobic membrane with a feed side for receiving the produced water stream and a product side for receiving a deionized water stream. A heat recovery heat exchanger is in communication with the membrane distillation unit for receiving two streams, one from each side of the hydrophobic membrane, such that heat is exchanged between the two streams. A line leaving the heat exchanger returns a heated stream from the heat exchanger to a location in a line upstream of the membrane distillation unit. A brine tank in communication with the membrane distillation unit receives a portion of a stream from the membrane product side and contains a concentrated brine solution containing the portion of the stream from the membrane product side and sodium chloride.