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).

A method for concentrating and crystallizing fermentable carboxylic acids, salts, and mixtures thereof may involve the use of carboxylic acids that have a defined temperature dependence of the solubility and of the osmotic pressure. The carboxylic acids may be concentrated by a membrane method and subsequently crystallized out by a cooling crystallization and isolated. In some examples, the membrane method may involve nanofiltration, reverse osmosis, and/or membrane distillation for separation into a concentrate and a permeate. Similarly, an apparatus for implementing such methods may include a nanofiltration, reverse osmosis, and/or membrane distillation unit for concentrating the carboxylic acid, and at least one cooling crystallization unit for crystallizing the carboxylic acid.

Embodiments provide methods and structures for purification or volume reduction of a brine by an advanced vacuum distillation process (AVMD) to achieve higher flux by passage of vapors through an AVMD distillation unit. In one example, brine is circulated in a tank. The tank may include one or more membrane pouches that are submerged in the circulating brine or placed above the water level of the hot circulating brine. In other embodiments the membrane pouches are outside of the tank that includes the hot circulating brine but still in communication with it. The circulating brine is heated, allowing creation of water vapor. Using a vacuum, the water vapor is drawn through the membrane, where it may be condensed and subjected to further beneficial use. This process can concentrate to levels to generate crystals or solids, which can be separated and utilized.

A method of making a polyimide membrane includes mixing dianhydride and phenylenediamine monomers in a first solvent to form a mixture; heating the mixture thereby polymerizing to form a polyimide polymer in a crude mixture; precipitating and separating the polyimide polymer from the crude mixture; mixing and dissolving the polyimide polymer in a second solvent to form a polyimide solution; applying the polyimide solution onto a surface of a substrate to form a polyimide liquid layer on the substrate; immersing the substrate after the applying in at least one liquid medium selected from the group consisting of water and alcohol, thereby precipitating the polyimide polymer from the polyimide solution to form the polyimide membrane disposed on the surface of the substrate. A desalination system containing the polyimide membrane, and a desalination process.

A replaceable membrane distillation module has a membrane distillation plate with an upper portion and a lower portion at two ends respectively. Two upper holes and two lower holes are defined through the upper portion and the lower portion at two ends respectively. A distillation portion is recessed in at least one side of the membrane distillation plate, and a distillation membrane covers on the distillation portion that a distillation space forms between the distillation portions and the distillation membrane. Multiple channels are disposed in the membrane distillation plate to communicate one of the upper holes, the distillation space and one of the lower flow holes. A blocking element is selectively combined with one of the upper holes or one of the lower flow holes.

A process treats high temperature produced water by passing a stream to an electrocoagulation unit and then to a membrane distillation (MD) unit where the stream contacts a hydrophobic membrane on a feed side and deionized water contacts the membrane on a product side. A distilled water stream is recovered and collected with the product side stream to form a volume-depleted exit produced water stream on the feed side of the hydrophobic membrane. The exit product side stream is passed through a heat exchanger to form a stream that is returned to a location upstream of the MD unit for an additional pass through the MD unit, thereby recovering additional water. The stream can be returned multiple times to achieve high recovery and to form a final stream leaving the MD unit having a temperature from 40-60 ? C., a total oil and grease content no greater than 500 mg/L, and a suspended solids content no greater than 200 mg/L. A portion of the distilled water stream from the membrane distillation unit can be used to form a brine solution used to regenerate used ion exchange resin in a water softening system.

A process treats high temperature produced water by passing a stream to an electrocoagulation unit and then to a membrane distillation (MD) unit where the stream contacts a hydrophobic membrane on a feed side and deionized water contacts the membrane on a product side. A distilled water stream is recovered and collected with the product side stream to form a volume-depleted exit produced water stream on the feed side of the hydrophobic membrane. The exit product side stream is passed through a heat exchanger to form a stream that is returned to a location upstream of the MD unit for an additional pass through the MD unit, thereby recovering additional water. The stream can be returned multiple times to achieve high recovery and to form a final stream leaving the MD unit having a temperature from 40-60 C., a total oil and grease content no greater than 500 mg/L, and a suspended solids content no greater than 200 mg/L. A portion of the distilled water stream from the membrane distillation unit can be used to form a brine solution used to regenerate used ion exchange resin in a water softening system.

Device for producing pure water, where the water to be purified is caused to be membrane distilled using one or more units (1), wherein each of the units comprises a space which on its one side comprises a first disc-shaped wall (4,4) and on its other side a membrane (3,3) through which gaseous water can pass but not liquid water, and a second disc-shaped wall (5,10), which walls are disposed on different sides of and at a distance from the membrane, wherein water is led in between the first wall (4,4) and the membrane (3,3), and wherein the second wall (5,10) is caused to be colder than the water. The invention is characterized in that the first disc-shaped wall (4,4) is also a membrane through which gaseous water can pass but not liquid water, in that two adjacent membranes (3, 4; 3 4) are supported by a common frame (6), in that the space between the membranes is provided with an inlet opening (7,7) for water to be purified and an outlet opening (8,8), in that the second wall (5,10) is a part of a chamber (9) formed by two parallel walls, in that the chamber is provided with an inlet opening (11,11) for water which is colder than the water to be purified and provided with an outlet opening (12,12), and in that chambers (9,9) are arranged in parallel with the membranes at both sides of the frame (6).

A multi-stage sweeping gas membrane distillation (MS-SGMD) system and a method of use are provided. The MS-SGMD includes a plurality of modules, wherein each module includes a feed chamber fluidically coupled to a feed line and a carrier gas line, wherein the feed line introduces a liquid feed into the feed chamber from a liquid feed tank, and wherein the carrier gas line introduces a carrier gas into the feed chamber. Each module includes a sweeping gas chamber fluidically coupled to a sweeping gas line and a sweeping gas return line, wherein a sweeping gas is passed through the sweeping gas chamber. Each module further includes a membrane separating the feed chamber from the sweeping gas chamber, wherein the membrane allows transportation of vapor from the feed chamber to the sweeping gas chamber while blocking liquid from moving from the feed chamber to the sweeping gas chamber.

The present invention relates to an olefins-paraffins separation process in feed stream containing hydrocarbons with 2 to 4 carbon atoms by facilitated transport membrane specific to olefins, comprising a step (a) of feeding the feed stream containing hydrocarbons with 2 to 4 carbon atoms into distillation column and at least 1 stage of membrane unit connected to distillation column at the feed of distillation column and at least 1 stage of membrane unit connected to the side draw of distillation column and a step (b) of separating a portion of feed stream that is passed from the membrane unit, at least 1 stream is the product stream that mostly comprising olefins and at least 1 stream that mostly comprising paraffins.