This invention relates to a vacuum air gap membrane distillation system for desalination purposes. More particularly, this invention relates to a membrane distillation system with multiple cells in which the system's flux is increased due to the temperature and pressure differential within the system. The configuration of the vacuum air gap membrane distillation system allows for latent heat within the system to be recycled effectively reducing the energy consumption of the system.

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 vapor-absorption refrigeration (VAR) system. The VAR system includes a VAR section having a condenser, an absorber, an evaporator, a first desorber, a second desorber, a first heat exchanger, a second heat exchanger, at least four throttling valves, and at least two pumps. The VAR section heats a saline water feed stream using heat released from the absorber and the condenser, producing cooling effect. The VAR system includes a direct contact membrane distillation-absorber (DCMD-Abs) section receiving the hot saline water feed stream. The DCMD-Abs section comprises DCMD-Abs modules linked in series. Each DCMD-Abs module includes a saltwater feed compartment and a water compartment, and a membrane. Due to temperature difference between the saline water feed stream and cooling water stream, water vapors are produced by evaporation in the saltwater feed compartment and passes through the membrane to the water compartment to be condensed therein.

Disclosed herein is a method and apparatus that uses a brine from a well that is used to both generate electricity and recover valuable minerals present in the brine. The method and apparatus uses a hydrophobic membrane to separate water vapor from the brine to concentrate the brine that is then used to recover the minerals.

Disclosed herein is a method and apparatus that uses a brine from a well that is used to both generate electricity and recover valuable minerals present in the brine. The method and apparatus uses a hydrophobic membrane to separate water vapor from the brine to concentrate the brine that is then used to recover the minerals.

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.

Composite polyether block amide (PEBA) copolymer tubes incorporate an ultra-thin PEBA extruded layer that enables rapid moisture transfer and exchange through the tube. An extruded composite PEBA film may include a porous scaffold support and may be formed or incorporated into the composite PEBA tube. An extruded PEBA may be melted into pores of a porous scaffold support. Extruded PEBA may be wrapped on a mandrel or over a porous scaffold support to form a composite PEBA tube. A film layer may be applied over a wrapped composite PEBA film to secure the layers together. A support tube may be configured inside or outside of the PEBA tube.

A membrane-based assembly and process for cooling and/or de-vaporizing a gas. The assembly and process can provide sensible cooling and/or dehumidification of air, and can be contained within a single, integrated apparatus.

A membrane distillation arrangement (100) comprising: at least two dividers (120), each divider (120) having a top (122) and a base (124) and at least one side (126) which extends between the top (122) and the base (124); at least one transfer element (132) selected from a membrane, heat transfer component or combination thereof, each transfer element (132) having a top (134) and a base (136), each transfer element (132) being supported between two dividers (120); a plurality of perimeter seals (130), at least one perimeter seal (130) extending around the perimeter of the top (134) or the base (136) of each transfer element (132), each perimeter seal (130) forming a substantially fluid tight seal and a fluid flow space (140, 141) between the respective top (134) or base (136) of each transfer element (132) and a respective adjacent face of a divider (120). Each divider (120) includes at least one side inlet (114) and at least one side outlet (116), each side inlet (114) and side outlet (116) extending into the at least one side of each divider (120), and being in fluid communication with the respective fluid flow space (140, 141) formed between the adjacent transfer element (32) and the respective adjacent face of a divider (120).

The invention relates to a method of converting thermal energy into mechanical energy wherein a working liquid such as is evaporated to generate a stream of a working fluid. According to the invention, the stream of the working fluid is a stream of pressurized distillate produced by evaporation and condensation using a direct contact membrane distillation (DCMD) unit, said stream of pressurized distillate having a pressure of at least one bar, and a converter such as a turbine is used for generating mechanical energy from said stream of said pressurized distillate. The invention also relates to an apparatus for performing the method.