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 invention relates to regenerative, solid sorbents for adsorbing carbon dioxide from a gas mixture, including air, with the sorbent including a modified polyamine and a solid support. The modified polyamine is the reaction product of an amine and an epoxide. The sorbent provides structural integrity, as well as high selectivity and increased capacity for efficiently capturing carbon dioxide from gas mixtures, including the air. The sorbent is regenerative, and can be used through multiple cycles of adsorption-desorption.

The invention relates to a method to produce a particulate activated carbon material for capturing CO.sub.2 from air,

wherein the particulate activated carbon is impregnated with alkali carbonate salt such as K.sub.2CO.sub.3; and wherein the impregnated particulate activated carbon either has, determined using nitrogen adsorption methods, a pore volume of at least 0.10 cm.sup.3/g for pore sizes of at least 5 nm and a pore volume of at most 0.30 cm.sup.3/g for pore sizes of less than 2 nm or is based on a mixture of different alkali carbonate salts, or has a particular pore surface for pore sizes in the range of 2 nm-50 nm.

The hydrogen storage product comprises one or more reduced-graphene oxide layers functionalized with a boron species and decorated with an alkali or alkaline earth metal. Each layer of the structure further comprises boron-oxygen functional groups comprising oxygen atoms bonded to boron atoms. The hydrogen storage product has a composition suitable for physisorption of hydrogen molecule, and operates to reversibly store hydrogen under operating conditions of low pressure and ambient temperature.

Polyamines with lengths carefully tailored to the framework dimensions are appended to metal-organic frameworks such as Mg.sub.2(dobpdc) (dobpdc4-=4,4′-dioxidobiphenyl-3,3′-dicarboxylate) with the desired loading of one polyamine per two metal sites. The polyamine-appended materials show step-shaped adsorption and desorption profiles due to a cooperative CO.sub.2 adsorption/desorption mechanism. Several disclosed polyamine-appended materials exhibit strong ability to capture CO.sub.2 from various compositions. Increased stability of amines in the framework has been achieved using high molecular weight polyamine molecules that coordinate multiple metal sites in the framework. The preparation of these adsorbents as well as their characterization are provided.

Methods of drying streams that include propylene oxide. The methods may include contacting a stream that includes propylene oxide with molecular sieves. The molecular sieves may be in a drying unit, and may be regenerated. The streams that include propylene oxide may include one or more other organic compounds.

An adsorption material is disclosed that comprises a metal-organic framework and a plurality of Hgands. The metal-organic framework comprising a plurality of metal ions. Each respective ligand in the plurality of ligands is amine appended to a respective metal ion in the plurality of metal ions of the metal-organic framework. Each respective ligand in the plurality of ligands comprises a substituted 1,3-propanediamine. The adsorbent has a CO2 adsorption capacity of greater than 2.50 mmol/g at 150 mbar CO2 at 40° C., Moreover, the adsorbent is configured to regenerate at less than 120° C. An example ligand is diamine 2,2-dimethyl-1,3-propane-diamine. An example of the metal-organic framework is Mg2(dobpdc), where dobpdc.sup.4− is 4,4′-dioxidobiphenyl-3,3′-dicarboxylate. Example applications for the adsorption material are removal of carbon dioxide from flue gas and biogasses.

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.

Processes for regenerating sorbents at high temperatures, and associated systems, are generally described.

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.