A multi-stage process to remove contaminant gases from raw methane streams is provided. The present technology is an innovative solution to recover and purify biogas by use of a process having at least two pressure swing adsorption stages. Taking advantage of the presence of carbon dioxide in the raw biogas streams, nitrogen and oxygen are bulky removed in the first stage, using selective adsorbents, and a nitrogen and oxygen-depleted intermediate stream is yielded to the second stage. The second stage employs an adsorbent or adsorbents to selectively remove carbon dioxide and trace amounts of remaining nitrogen and oxygen, thus producing a purer methane stream that meets pipeline and natural gas specifications.

The present disclosure relates to a solid adsorbent for capturing carbon dioxide (CO.sub.2) from a gas stream comprising CO.sub.2, the solid adsorbent comprising an amine covalently bonded to a polymer resin (e.g., a polystyrene resin), wherein the solid adsorbent has a CO.sub.2 uptake capacity of greater than about 7 wt. % at a temperature of about 40° C., and wherein the solid adsorbent has a CO.sub.2 uptake capacity of less than about 1.5 wt. % at a temperature of about 100° C., as measured when the gas stream further comprises a concentration of the CO.sub.2 of about 4 vol. %, by volume of the gas stream.

A porous carbon material composite formed of a porous carbon material and a functional material and equipped with high functionality. The porous carbon material composite is formed of (A) a porous carbon material obtainable from a plant-derived material having a silicon (Si) content of 5 wt % or higher as a raw material; and (B) a functional material adhered on the porous carbon material, and has a specific surface area of 10 m.sup.2/g or greater as determined by the nitrogen BET method and a pore volume of 0.1 cm.sup.3/g or greater as determined by the BJH method and MP method.

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.

Disclosed is a method of controlling an air supply system for a fuel cell. The air supply system includes a fuel cell stack, an air channel to supply air to an inlet of the fuel cell stack, a gas adsorption unit disposed on the air channel and configured to adsorb oxygen contained in air introduced into the air channel. In particular, the method includes: determining whether a power generation operation of the fuel cell stack is resumed; when the power generation operation of the fuel cell stack is resumed, controlling a voltage source to apply a voltage to the gas adsorption unit; and supplying air to the fuel cell stack through the air channel in a state in which the voltage is applied to the gas adsorption unit.

Sorbent materials comprising a nanofiber composite including a polymeric material defining a continuous phase and at least one metal organic framework (MOF) material defining a discontinuous phase are provided. The at least one MOF material is dispersed throughout the continuous phase of the polymeric material. Fibrous mats comprising the sorbent materials are also provided. Water harvesting devices utilizing the sorbent materials are also provided.

Disclosed herein are processes and systems for removing heavy C5+ hydrocarbon components from a natural gas feed gas by subjecting the natural gas feed gas stream to an adsorber. The adsorber in the processes and systems described herein operating at a pressure that may be associated with improved adsorption capacity and longer breakthrough time.

A SO.sub.2 adsorption material, a preparation method therefor and an application thereof, and a method for removing SO.sub.2 from flue gas containing SO.sub.2 are provided. The SO.sub.2 adsorption material contains a carbonized metal organic framework material and a sulfite loaded on the carbonized metal organic framework material, and the carbonized metal organic framework material is a carbonized material obtained by carbonizing a metal organic framework material. On the basis of the total weight of the SO.sub.2 adsorption material, the loading amount of sulfite is not higher than 10 wt %. The SO.sub.2 adsorption material has a relatively high SO.sub.2 adsorption capacity, and may be desorbed and regenerated by heating, and the adsorption capacity still remains at a relatively high level after multiple cycles of adsorption-desorption.

The invention belongs to the field of eliminating pollutant gases. In particular, the invention belongs to the field of pollutant gas-absorbing material such as CO2, SO2, NOx and VOCs.

The present invention relates to a fresh composite or composite paste and a composite material comprising aggregates of recycled concrete, porous carbon, a binder and optionally water, as well as to the method for manufacturing the composite and the use thereof for sanitizing air (indoor or outdoor). The invention also relates to an article (for example, an anti-noise wall, a tunnel lining, an indoor decoration, an item of street furniture, etc.) comprising the composite according to the invention.

The present disclosure relates to a single-use filter component for removing NO.sub.2 in an air-treatment system, the component comprising a polymeric composition as an air-filtration medium, the polymeric composition comprising a plurality of free vinyl groups, wherein the component permits inspection of the air-filtration medium by an end-user to determine when the filter is spent, based on a white to yellow colour change, or comprises an optical sensor configured to notify the end-user of the colour change. The present disclosure further relates to a single-use filter component for simultaneously removing NO.sub.2 in an air-treatment system, wherein the component comprises a HEPA filter formed from a polymeric composition comprising a plurality of free vinyl groups. The present disclosure further relates to an air treatment system, to a method of treating air and to the use of a polymer or copolymer of divinylbenzene for forming an air-filtration medium.