According to one aspect of the present invention, a pressure swing adsorption (PSA) device includes an adsorption tower configured to introduce hydrogen gas and adsorb impurity components in the hydrogen gas by using a pressure swing adsorption (PSA) method, an adsorbent of one layer made of activated carbon or an adsorbent of two layers in which activated carbon and zeolite are stacked being disposed in the adsorption tower, the hydrogen gas containing carbon monoxide (CO) of 0.5 vol % or more and 6.0 vol % or less and methane (CH.sub.4) of 0.4 vol % or more and 10 vol % or less as the impurity components; and a densitometer configured to detect a concentration of CO in the hydrogen gas discharged from the adsorption tower, wherein the impurity components are adsorbed and removed to cause the CO concentration measured by the densitometer to fall below a threshold.

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.

The present invention relates to a process cycle that allows for the stable production of mid-range purity oxygen from air, using traditional system designs. Typical cycles have a limited production benefit when generating O.sub.2 at lower than 90% purity, however they suffer a production loss at higher purity. The process cycles of the invention are capable of producing significantly more contained O.sub.2 at a lower purity. In addition to enhanced production capacity, lower power consumed per mass of product and more stable product purity and flow are realized by the process of the invention compared to traditional alternatives.

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 reducing process disturbances during pressurization of an adsorber in an air separation unit is provided, in which the air separation unit includes a front end purification unit and an air buffer tank. In one embodiment, the method can include the steps of: pressurizing a first adsorber while a second adsorber operates in an adsorption cycle, wherein the step of pressurizing the first adsorber further includes the steps of withdrawing a pressurized air stream from the air buffer tank and introducing the pressurized air stream to the first adsorber until the first adsorber is at a target pressure, wherein the air buffer tank is in fluid communication with the booster air compressor, wherein the method further includes the step of continually sending a first portion of air flow from the booster air compressor to the air buffer tank and continually sending a second portion of air flow from the booster air compressor to a system of columns within a cold box for rectification therein.

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 separating at least one hydrocarbon from a feed containing a mixture of at least one hydrocarbon and nitrogen, comprising contacting the feed with an adsorbent comprising a porous support wherein the porous support comprises exchangeable cations and at least a portion of the exchangeable cations are organic cations.

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.