A first process and sorbent for removing ammonia from a gaseous environment, the sorbent comprised of graphene oxide having supported thereon at least one compound selected from metal salts, metal oxides and acids, each of which is capable of adsorbing ammonia. A second process and sorbent system for removing ammonia and a volatile organic compound from a gaseous environment; the sorbent system comprised of two graphene-based materials: (a) the aforementioned graphene oxide, and (b) a nitrogen and oxygen-functionalized graphene. The sorbents are regenerable under a pressure gradient with little or no application of heat. The processes are operable through multiple adsorption-desorption cycles and are applicable to purifying and revitalizing air contaminated with ammonia and organic compounds as may be found in spacesuits, aerospace cabins, underwater vehicles, and other confined-entry environments.

The present invention provides for a method utilizing horizontal and vertical Adsorber bed(s) with multiple different reversible blower(s) and inputs operating in a vacuum pressure swing adsorption separation process to separate gases. The process is designed to provide a safer and more cost-effective adsorption system on a larger scale that captures and utilizes energy typically wasted during equipment transitions thereby achieving overall higher power efficiency.

Disclosed are processes and systems for the removal of water from a feed stream utilizing swing adsorption processes including an adsorbent bed comprising an adsorbent material which is a cationic zeolite RHO. The cationic zeolite RHO comprises at least one, preferably two, metal cations selected from Group 1 and 2 elements (new Group 1-18 IUPAC numbering). The swing adsorption processes and systems utilizing the cationic zeolite RHO have an adsorption selectivity for water and are useful in selective dehydration of commercial feed streams. The cationic zeolite RHO additionally has an exceptionally high water adsorption stability for use in feed streams with wet acid gas environments operating under cyclic swing adsorption conditions.

An aspect of the disclosure is a diagnostic system. The diagnostic system includes a communications interface, an output gas interface, one or more sensors, and a controller that is configured to execute a diagnostic procedure. The diagnostic procedure causes the controller to transmit one or more commands to the oxygen concentrator using the communications interface, to obtain the one or more gas property measurements from the one or more sensors during operation of the oxygen concentrator, and to determine a diagnostic result by comparing the one or more gas property measurements obtained from the one or more sensors during operation of the oxygen concentrator to a testing standard described by the diagnostic procedure. The diagnostic procedure also causes the controller to output information regarding the diagnostic result for display to a user.

Provided herein are metal organic frameworks comprising metal nodes and N-donor organic ligands which have high selectivity and stability in the present of gases and vapors including H.sub.2S, H.sub.2O, and CO.sub.2. Methods include capturing one or more of H.sub.2S, H.sub.2O, and CO.sub.2 from fluid compositions, such as natural gas.

A method for producing oxygen from air using vacuum swing adsorption by means of a unit comprising at least two adsorbers each following, with an offset a pressure cycle, with a decompression step comprising at least a co-current first decompression sub-step for the partial balancing of pressure with the other adsorber which is performing counter-current recompression by means of a balancing valve, and, at least for one cycle out of three, a dead time sub-step which succeeds the first decompression sub-step, the method including a pressure of X bar at the end of the first decompression sub-step for the cycles that do not have a dead time sub-step, and a pressure of X bar at the end of the dead time sub-step, opening the balancing valve identically during the first decompression sub-step and the dead time sub-step, for the cycles that do have a dead time sub-step.

Primary, secondary (1,2) alkylethylenediamine- and alkylpropylenediamine-appended variants of metal-organic framework are provided for CO.sub.2 capture applications. Increasing the size of the alkyl group on the secondary amine enhances the stability to diamine volatilization from the metal sites. Two-step adsorption/desorption profiles are overcome by minimizing steric interactions between adjacent ammonium carbamate chains. For instance, the isoreticularly expanded framework Mg.sub.2(dotpdc) (dotpdc.sup.4=4,4-dioxido-[1,1:4,1-terphenyl]-3,3-dicarboxylate), yields diamine-appended adsorbents displaying a single CO.sub.2 adsorption step. Further, use of the isomeric framework Mg-IRMOF-74-II or Mg.sub.2(pc-dobpdc) (pc-dobpdc.sup.4=3,3-dioxidobiphenyl-4,4-dicarboxylate, pc=para-carboxylate) also leads to a single CO.sub.2 adsorption step with bulky diamines. By relieving steric interactions between adjacent ammonium carbamate chains, these frameworks enable step-shaped CO.sub.2 adsorption, decreased water co-adsorption, and increased stability to diamine loss. Variants of Mg.sub.2(dotpdc) and Mg.sub.2(pc-dobpdc) functionalized with large diamines such as N-(n-heptyl)ethylenediamine have utility as adsorbents for carbon capture applications.

The adsorber vessel is configured for radial flow between a center column and a perimeter manifold. Space between the center column and the perimeter manifold contains adsorption media. End caps close off ends of the vessel. An inlet and an outlet are configured within one of the end caps to feed starting gas into the center column or perimeter manifold, and to draw off product gas from the perimeter manifold or center column. An end cap can be removed to provide access for media loading between the center column and the perimeter manifold. Media is preferably provided within cartridges which can slide into this media space. Cartridges can be concentric with one cartridge inboard of the other, or can be stacked vertically. A spring plate can be provided on an open end to hold the media in position, while sealing the open end of the adsorber vessel.

A pressure swing adsorption (PSA) system and methods for controlling each PSA cycle performed by the PSA system to produce oxygen enriched gas during productive portions of a user breathing cycle, and to cease production of oxygen enriched gas during non-productive portions of the user breathing cycle, is provided. The PSA system synchronizes PSA cycle phases including adsorption and desorption phases with a user's individual inhalation and exhalation phases, on a breath by breath basis, such that each PSA cycle can be dynamically varied from a succeeding PSA cycle, in real time in response to variations in the user's breathing cycle. An oxygen delivery device including a breathing cycle sensor provides breathing cycle inputs to a controller for use with at least one algorithm to detect breathing flow phases during each user breath, and to synchronize each PSA cycle to the user's breathing flow phases, on a breath-by-breath basis.

A ventilator includes an enclosure, a tubing configured to receive an input gas, and a flow outlet airline in fluid communication with the tubing. The flow outlet airline includes an airline outlet. The ventilator further includes a breath detection airline including an airline inlet. The airline inlet is separated from the airline outlet of the flow outline airline. The ventilator further includes a pressure sensor in direct fluid communication with the breath detection airline. The ventilator includes a controller in electronic communication with the pressure sensor and an internal oxygen concentrator in fluid communication with the tubing. The internal oxygen concentrator is entirely disposed inside the enclosure.