A method for removal of at least a portion of carbon dioxide from an aqueous fluid such as a blood fluid includes placing a first surface of at least one membrane through which carbon dioxide and at least one acid gas other than carbon dioxide can pass in fluid in contact with the fluid. The membrane limits or prevent passage of the fluid therethrough. A carrier or sweep gas including the acid gas other than carbon dioxide is passed over a second surface (which is typically opposite the first surface) of the membrane so that the acid gas other than carbon dioxide can pass through the membrane into the fluid, and carbon dioxide from the fluid can pass from the liquid, through the membrane, and into the sweep gas.

A process for separating carbon dioxide from a fluid containing carbon dioxide, NO.sub.2, and at least one of oxygen, argon, and nitrogen comprises the steps of separating at least part of the fluid into a carbon dioxide enriched stream, a carbon dioxide depleted stream comprising CO.sub.2 and at least one of oxygen, argon, and nitrogen and a NO.sub.2 enriched stream and recycling said NO.sub.2 enriched stream upstream of the separation step.

Single-stage and multi-stage systems and methods for the recovery of critical elements in substantially pure form from lithium ion batteries are provided. The systems and methods include supported membrane solvent extraction using an immobilized organic phase within the pores of permeable hollow fibers. The permeable hollow fibers are contacted by a feed solution on one side, and a strip solution on another side, to provide the simultaneous extraction and stripping of elements from dissolved lithium ion cathode materials, while rejecting other elements from the feed solution. The single- and multi-stage systems and methods can selectively recover cobalt, manganese, nickel, lithium, aluminum and other elements from spent battery cathodes and are not limited by equilibrium constraints as compared to traditional solvent extraction processes.

Separation of a gas mixture comprising first and second gases may be improved using two cascaded stages of gas separation membrane modules that includes the additional techniques of cooling the feed gas stream that is fed to the feed stage and using a portion of the feed stage retentate as a sweep gas on the feed stage.

Electro oxidation membrane evaporator 1 comprises sweep air handler 60; fluid tank 20 defining a fluid container; fluid contactor/separator 30; oxidation cell 40; and scrubber 80. Electro oxidation membrane evaporator 1 may allow higher percent water recovery from wastewater prior to delivering brine to a brine water recovery system and can allow O.sub.2 from air such as cabin air to continuously diffuse into the wastewater as O.sub.2 is consumed to generate oxidants, helping to eliminate the low oxidant environment at the end of the cycle that causes pH to remain high, and low pH prevents precipitates from forming for longer so more water can be evaporated from the wastewater.

The present invention relates to a crossflow membrane module configured to separate a feed fluid into a permeate fluid and a residue fluid across one or more membrane sheet(s). The crossflow module comprises a second end offset from a first end along the first direction where an inlet is provided at the first end and an outlet is provided at the second end. The one or more membrane sheet(s) each have a first portion and a second portion. A conduit is adjacent to the first side of each membrane sheet and is configured to receive and output the permeate fluid separated from the feed fluid. The second portion of the membrane sheet has a greater permeance for a major component than the first portion such that the second part of the permeate fluid, which is generated by separation across the second portion of the membrane sheet, has a higher concentration of the major component than the first part of the permeate fluid, which is generated by separation across the first portion. The second portion is spaced apart from the first side of the membrane sheet along the second direction thereby causing the second part of the permeate gas to flow towards the first side of the membrane sheet such that the second part of the permeate gas mixes with the first part of the permeate gas thereby reducing the concentration of the minor component in the first part of the permeate gas.

A gas separation system for controlling a concentration of a first gas species and a second gas species in an outlet gas comprises a splitter unit. The splitter unit comprises a gas membrane system having a gas inlet port. The gas inlet port is in fluid connection with an air intake. A membrane is a selective barrier and allows some things to pass through but stops others.

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.

Systems, devices, and methods are provided for removing carbon dioxide from a target fluid, such as, for example, blood, to treat hypercarbic respiratory failure or another condition. A device is provided including first and second membrane components for removing dissolved gaseous carbon dioxide and bicarbonate from the fluid, which can be done simultaneously. The device can be in the form of a cartridge configured for use in a dialysis system. A method of treatment is also provided, involving drawing blood from a patient and bringing the patient’s blood in contact with a first membrane component having a sweep gas passing therethrough, and a second membrane component having a dialysate passing therethrough. The dialysate’s composition can be selected such that charge neutrality is maintained.

Membranes, methods of making the membranes, and methods of using the membranes are described herein. The membranes can comprise a support layer, and a selective polymer layer disposed on the support layer. The selective polymer layer can comprise a selective polymer matrix and carbon nanotubes dispersed within the selective polymer matrix. The carbon nanotubes can comprise multi-walled carbon nanotubes wrapped in a hydrophilic polymer, such as polyvinylpyrrolidone or a copolymer thereof, such as poly(1-vinylpyrrolidone-co-vinyl acetate). The membranes can exhibit selective permeability to gases. As such, the membranes can be for the selective removal of carbon dioxide and/or hydrogen sulfide from hydrogen and/or nitrogen.