Abstract: The invention is a pressure swing adsorption system. The pressure swing adsorption system has a plurality of primary adsorbent beds and at least one secondary adsorbent bed. The feed gas stream is flowed to a primary adsorbent bed loaded with an adsorbent that will preferentially adsorb certain components in the feed gas. Non-preferentially adsorbed components flow from the adsorbent bed during this time. Upon saturation of the adsorbent with the adsorbed components, the flow of feed gas is ceased. The adsorbent is fully loaded with the preferentially adsorbed component and there is feed gas in the void space between the adsorbent particles. This primary adsorbent bed undergoes regeneration by partial depressurization through the secondary adsorbent bed followed by a complete depressurization to a final lower pressure. There can be two or more primary adsorbent beds and there will be at least one secondary adsorbent bed.

Abstract: A natural gas feed stream containing significant quantities of nitrogen and/or carbon dioxide can be increased to a content of greater than 95 percent by volume of natural gas, and preferably greater than about 98 percent, by passing the natural gas feed stream sequentially through three adsorbent beds that are cycled through seven phases comprising: an adsorption phase to adsorb a first gas, a first depressurization phase to remove feed gas from the voids in the adsorbent bed, a recycle phase to remove a second gas from the adsorbent by the passage of a second depressurization gas therethrough and to produce a recycle gas, a second depressurization phase to reduce the adsorbent bed pressure to about ambient and to produce the second depressurization gas, an evacuation phase where the pressure in the adsorbent is further reduced and an enriched primary gas product stream recovered, a pressurization phase where the pressure in the adsorbent bed is increased using secondary product gas from a bed in an adsorpti

Abstract: The present process is directed to the efficient recovery of helium gas from gas streams which contain about 25 percent by volume or more helium. The process comprises two stages of pressure swing adsorption, each stage being comprised of a plurality of interconnected adsorbent beds. In the first stage of pressure swing adsorption which is comprised of about five phases, the helium content of the gas stream is increased to 95 percent by volume or more. A secondary product gas stream from the first stage of pressure swing adsorption is fed to the second stage of pressure swing adsorption. The second stage of pressure swing adsorption increases the helium content of this primarily non-helium product gas to more than about 50 percent by volume. This gas now with a helium content of more than about 50 percent by volume is fed along with the gas stream as the input gas to the first stage of pressure swing adsorption.

Abstract: The disclosed hybrid membrane and pressure swing adsorption process can recover helium from source streams of about 0.5 to 5 percent by volume helium and concentrate the helium to a concentration of greater than about 98 percent by volume. The process comprises a membrane separation followed by two stages of pressure swing adsorption which are used in series. The source gas will primarily contain hydrocarbons but will contain some nitrogen. The membrane unit will contain a semipermeable membrane which is permeably selective for helium and will to the extent feasible reject hydrocarbons. The permeate gas will be increased in helium content by 2 to 10 times. Part of the residue gas is used in the regeneration of the adsorbent beds in the first stage of pressure swing adsorption. Each stage of pressure swing adsorption will contain a plurality of adsorbent beds, and will be cycled through multiple phases.

Abstract: The disclosed pressure swing adsorption processes can recover helium from source streams of less than about 10 percent by volume helium and concentrate the helium to a concentration of greater than about 98 percent by volume. Two stages of pressure swing adsorption are used in series. The source of the helium gas will be natural gas wells. The source gas will contain hydrocarbons but in most instances the primary gas other than helium will be nitrogen. Each stage of pressure swing adsorption will contain a plurality of adsorbent beds, and preferably about four. In each stage the adsorbent beds will be cycled through multiple phases. In the first stage the adsorbent beds will sequentially undergo the phases of adsorption, recycle, depressurization, evacuation, helium pressurization and recycle feed pressurization.

Abstract: A natural gas feed stream containing significant quantities of nitrogen can be increased to a content of greater than 95 percent by volume of natural gas, and preferably greater than about 98 percent, by passing the natural gas feed stream sequentially through at least four adsorbent beds which are cycled through six phases comprising an adsorption phase to adsorb natural gas, a recycle phase to remove feed gas from the voids in the adsorbent bed and nitrogen from the adsorbent by the passage of a depressurization gas therethrough to produce a recycle gas, a depressurization phase to reduce the adsorbent bed pressure to about ambient and to produce the depressurization gas, an evacuation phase where the pressure in the adsorbent is further reduced and an enriched natural gas product stream recovered, a pressurization phase where the pressure in the adsorbent bed is increased using nitrogen gas from a bed in an adsorption phase, and further pressurizing the adsorbent bed in a recycle feed pressurization phase

Abstract: A simple, inexpensive method of inerting transport containers, particularly for goods which easily spoil in the air, such as foodstuffs, plants and flowers, by a gas which contains nitrogen and a predetermined concentration of up to about 5 vol.

Abstract: A method of and an arrangement for increasing the enrichment of nitrogen in an effluent gas obtained from a pressure swing adsorption system includes electrostatically negatively charging oxygen molecules in a feed gas such as air, and attracting the negatively charged oxygen molecules to a positively charged molecular sieve coke material employed as adsorbers in the pressure swing adsorption process.