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.

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.

A hydrocarbon adsorbent, according to one embodiment of the present invention, comprises a copper-containing ZSM-5 zeolite, wherein a Si/Al molar ratio of the ZSM-5 zeolite may be 11.5 to 40, and the amount of the copper included is 1 wt % to 10 wt %.

Crosslinked polymers made up of polymerized units of phenothiazine, pyrrole, and aldehyde. The crosslinked polymers are porous with a BET surface area in the range of 300-600 m.sup.2/g. A method of synthesizing the crosslinked polymers is described. Processes for using the crosslinked polymers as adsorbent materials for adsorbing gases (e.g. CO.sub.2 capturing), and separating fluid mixtures under dry and wet conditions are also introduced.

A hydrocarbon adsorbent, according to one embodiment of the present invention, comprises a copper-containing ZSM-5 zeolite, wherein a Si/Al molar ratio of the ZSM-5 zeolite may be 11.5 to 40, and the amount of the copper included is 1 wt % to 10 wt %.

A system for recovering nitrogen during regeneration of a treater, the system including an adsorbent bed downstream of the treater, wherein the adsorbent bed comprises an adsorbent operable to adsorb at least one impurity from a treater bed regeneration effluent stream comprising nitrogen to provide a nitrogen product having a higher nitrogen purity than a nitrogen purity of the treater bed regeneration effluent stream. A method for recovering nitrogen during regeneration of a treater is also provided.

A closed-loop nitrogen transport system including a first transfer line configured for nitrogen pressure conveyance of a polymer fluff from at least one upstream vessel to at least one downstream vessel, a second transfer line configured to return a nitrogen gas stream comprising primarily nitrogen from the at least one downstream vessel to the at least one upstream vessel, a conveyor blower operable to provide flow throughout the closed loop, and a treatment unit operable to remove hydrocarbons from at least a portion of the nitrogen gas stream comprising primarily nitrogen, to provide a purified nitrogen stream.

A process is provided for removing contaminants from olefin containing C.sub.4 streams. The streams are contacted with an X based zeolite adsorbent comprising greater than 88% X zeolite at a SiO.sub.2/Al.sub.2O.sub.3 ratio of less than 2.5 and an alkali metal salt present in excess of an amount required to achieve full exchange of cation sites on the X based zeolite. The resulting alkali oxide on a volatile free basis is less than 1% (by mass) of the X based adsorbent. The contaminants that are removed include sulfur, oxygenate, and nitrogen based contaminants.

A fuel tank inerting system is disclosed. The system includes a fuel tank and a catalytic reactor with an inlet, an outlet, a reactive flow path between the inlet and the outlet, and a catalyst on the reactive flow path. The catalytic reactor is arranged to receive fuel from a fuel flow path in operative communication with the fuel tank and oxygen from an oxygen source, and to catalytically react a mixture of the fuel and oxygen along the reactive flow path to generate an inert gas. An inert gas flow path provides inert gas from the catalytic reactor to the fuel tank. An adsorbent is disposed along the fuel flow path or along the reactive flow path.

The present invention relates to a device for the reversible adsorption of carbon dioxide from a gas mixture, comprising at least one adsorbent vessel comprising one or a plurality of gas permeable cartridge vessels of an inert and dimensionally stable material, and each cartridge comprising a suitable polymeric particular adsorbent having a primary amino functionality; to an arrangement including the device, and to a method for ad- and desorption of carbon dioxide.