Disclosed herein are rapid cycle pressure swing adsorption (PSA) process for separating O.sub.2 from N.sub.2 and/or Ar. The processes use a carbon molecular sieve (CMS) adsorbent having an O.sub.2/N.sub.2 and/or O.sub.2/Ar kinetic selectivity of at least 5 and an O.sub.2 adsorption rate (1/s) of at least 0.2000 as determined by linear driving force model at 1 atma and 86 F.

Disclosed herein are multi-bed rapid cycle pressure swing adsorption (RCPSA) processes for separating O.sub.2 from N.sub.2 and/or Ar, wherein the process utilizes at least five adsorption beds each comprising a kinetically selective adsorbent for O.sub.2 having an O.sub.2 adsorption rate (1/s) of at least 0.20 as determined by linear driving force model at 1 atma and 86 F.

A method for continuous pressure swing adsorption separation of a pressurized feed gas stream, including separating hydrocarbons heavier than methane from the pressurized feed gas stream by applying an adsorbent porous material to produce at least two product streams, a first product stream being substantially pure methane suitable for transport by natural gas pipeline, and a second product stream being substantially comprised of components with a greater molecular weight than methane.

A method for continuous pressure swing adsorption separation of a pressurized feed gas stream, including separating hydrocarbons heavier than methane from the pressurized feed gas stream by applying an adsorbent porous material to produce at least two product streams, a first product stream being substantially pure methane suitable for transport by natural gas pipeline, and a second product stream being substantially comprised of components with a greater molecular weight than methane.

A method for continuous pressure swing adsorption separation of a pressurized feed gas stream, including separating hydrocarbons heavier than methane from the pressurized feed gas stream by applying an adsorbent porous material to produce at least two product streams, a first product stream being substantially pure methane suitable for transport by natural gas pipeline, and a second product stream being substantially comprised of components with a greater molecular weight than methane.

An adsorbent separates methanol and other alcohols from gas and liquid oxygenates and hydrocarbon streams with a low silica faujasite (LSX) in a mono-, bi, or tri-cation alkali and/or alkaline-earth metal forms. The LSX has silicon to aluminum ratio from about 0.9 to about 1.15 and an ion exchange degree for each alkali or alkaline-earth metal in the range of about 10 to about 99.9% equiv. The gas streams for treatment include natural gas, individual hydrocarbons, or vaporized alkyl esters of carboxylic acids, or methyl tert-alkyl ethers and their mixtures with hydrocarbons. The liquid streams include liquefied natural gas (LNG), liquefied petroleum gas (LPG), natural gas liquid (NGL), individual hydrocarbons C.sub.3-C.sub.5, and monomers, alkyl esters of carboxylic acids including methyl acetate, methyl, ethyl, butyl acrylates and methacrylate, methyl tert-alkyl ethers including methyl tert-butyl ether (MTBE) and methyl tert-amyl ether (TAME). The adsorbent is especially suited for temperature swing or pressure swing adsorption processes.

Disclosed herein are rapid cycle pressure swing adsorption (PSA) process for separating O.sub.2 from N.sub.2 and/or Ar. The processes use a carbon molecular sieve (CMS) adsorbent having an O.sub.2/N.sub.2 and/or O.sub.2/Ar kinetic selectivity of at least 5 and an O.sub.2 adsorption rate (1/s) of at least 0.2000 as determined by linear driving force model at 1 atma and 86 F.

Disclosed herein are multi-bed rapid cycle pressure swing adsorption (RCPSA) processes for separating O.sub.2 from N.sub.2 and/or Ar, wherein the process utilizes at least five adsorption beds each comprising a kinetically selective adsorbent for O.sub.2 having an O.sub.2 adsorption rate (1/s) of at least 0.20 as determined by linear driving force model at 1 atma and 86 F.

A carbon dioxide recovery apparatus has a separator which separates carbon dioxide from a gas by utilizing adsorption and desorption of carbon dioxide to and from an adsorbent caused by pressure fluctuation, the separator including a pressurizer which pressurizes the gas to a pressure that the adsorbent is capable of adsorbing carbon dioxide, and has a dryer having a hygroscopic agent for drying the gas. A regeneration system supplies the residual gas discharged from the separator to the dryer as a regeneration gas for regenerating the hygroscopic agent in the dryer, and the regeneration gas to be supplied to the dryer is heated by an energy converter by utilizing a pressure of a post-regeneration gas discharged by the regeneration of the hygroscopic agent.

Methods and systems for capture of CO.sub.2 from a hydrated gaseous stream are described. Systems can be utilized for direct air capture of CO.sub.2 and incorporate a low energy temperature-vacuum swing adsorption (TVSA) process. A TVSA process can include a multi-step CO.sub.2 capture bed regeneration process that includes depressurization of the bed, heating of the bed, venting and purging of the bed, and cooling of the bed. Multiple beds can be cycled between CO.sub.2 capture and regeneration, during which captured CO.sub.2 is recovered. Off-gas from a CO.sub.2 capture bed can be used in regenerating a parallel bed for increased efficiency.