Abstract: A process and apparatus for separating the components of a gas mixture in a pair of adsorption vessels using a single gas compressor/pump to move gas into and out of the adsorption vessels. The cycle is such that the gas compressor/pump is in continuous operation. The adsorption cycle is non-symmetrical in that the series of steps carried out in one of the adsorbers is not the same as the series of steps carried out in the other adsorber. The apparatus includes an intermediate gas storage container which is used to temporarily store gas removed from the nonadsorbed gas outlet end of the adsorption vessels so that it can be used to partially pressurize the adsorption vessels upon completion of the adsorbent regeneration step of the adsorption cycle.

Abstract: An installation for the treatment of fluid having a receptacle (1) defining a non-vertical portion of a path for fluid through at least two adjacent masses (A; B; C) of particulate materials, typically different from each other, each mass being in direct contact with its neighbor or neighbors, without the interposition of a separating grid. The installation is particularly useful for the separation or drying of air.

Abstract: An air separation system and method for producing a plurality of oxygen product streams at varying pressures and purities. The system combines a VPSA oxygen generator with a multi-stage cascade membrane unit to provide a high pressure, low purity product stream and a low pressure, high purity product stream.

Abstract: A container for carbon molecular-sieve material which is designed to prevent contamination of carbon materials within the container. The container includes a hollow section with a preferably circular internal cross-section and a rectangular or square external cross-section. Attached to each end of the hollow section are screened structures designed to retain the molecular-sieve material within the hollow section. These screened structures are preferably secured in place by clamping rings. The hollow section can be hermetically sealed for transport and can be sealed by cover plates and bolts.

Abstract: A rotary valve system which includes of a pair of valve assemblies each of which has valve parts with flat faces which, when pressed together and rotated, provide valving action between various ports incorporated in one valve part of each assembly. The first valve part of each assembly contains a circular array of through openings, each of which is connected to a conduit. The second valve part of each assembly contains several passages which provide communication between various openings of the first valve part and valve apertures located in the second valve part of each assembly. The second valve part of one assembly also contains one or more passages which provide communication between members of one or the other array of openings. The valve system can be effectively used to automate operation of a gas or liquid adsorption system comprising two or more adsorption vessels, the number of vessels being equivalent to the total number of openings in either array.

Abstract: An installation for the treatment of fluid having a receptacle (1) defining a non-vertical portion of a path for fluid through at least two adjacent masses (A; B; C) of particulate materials, typically different from each other, each mass being in direct contact with its neighbor or neighbors, without the interposition of a separating grid. The installation is particularly useful for the separation or drying of air.

Abstract: A rotary valve assembly which includes a pair of valve parts with flat faces which, when pressed together and rotated, provide valving action between various ports incorporated in one of the valve parts. The first valve part contains two circular arrays of through openings, each of which is connected to a conduit. The second valve part contains several passages which provide communication between various openings of the first valve part and valve ports located in the second valve part. The second valve part also contains one or more passages which provide communication between members of one array of openings and between members of the other array of openings. The valve assembly can be effectively used to automate operation of a gas or liquid adsorption system comprising two or more adsorption vessels, the number of vessels being equivalent to the total number of openings in either array.

Abstract: A rotary valve assembly which includes of a pair of valve parts with flat faces which, when pressed together and rotated, provide valving action between various ports incorporated in one of the valve parts. The first valve part contains two circular arrays of through openings, each of which is connected to a conduit. The second valve part contains several passages which provide communication between various openings of the first valve part and valve ports located in the second valve part. The second valve part also contains one or more passages which provide communication between two openings of one array of openings and one opening of the other array of openings. The valve assembly can be effectively used to automate operation of a gas or liquid adsorption system comprising two or more adsorption vessels, the number of vessels being equivalent to the total number of openings in either array.

Abstract: An adsorption process and system for the selective adsorption of a more readily adsorbable component, such as nitrogen, as from air or other feed gas mixture is carried out using a composite adsorbent bed containing different adsorbent materials positioned in separate zones in which the temperature conditions favor adsorption performance of the particular adsorbent material under applicable processing conditions in each zone. A method for the selection of the adsorbent materials is based on Adsorption Figure of Merit values.

Abstract: A rotary valve assembly which includes of a pair of valve parts with flat faces which, when pressed together and rotated, provide valving action between various ports incorporated in one of the valve parts. The first valve part contains two circular arrays of through openings, each of which is connected to a conduit. The second valve part contains several passages which provide communication between various openings of the first valve part and valve ports located in the second valve part. The second valve part also contains one or more passages which provide communication between members of one array of openings. The valve assembly can be effectively used to automate operation of a gas or liquid adsorption system comprising two or more adsorption vessels, the number of vessels being equivalent to the total number of openings in either array. Use of the valve assembly in an adsorption system eliminates the need for many of the valves required in conventional multivessel adsorption systems.

Abstract: A process and a system for producing helium from a helium-bearing feed gas that is purified in a cryogenic processing unit to produce cryogenic crude helium containing at least 10% helium. The cryogenic crude helium is directly introduced into a thermal swing helium refinery where it is refined. Refrigeration is supplied to the refinery by the cryogenic crude helium from the cryogenic processing unit.

Abstract: A device for separation of gas by adsorption, of the so-called VSA or MPSA type, comprises, between a utilization line (L) and a source (S) of gaseous mixture to be separated, at least one module (M) comprising in series a reversible rotary machine (R), typically a Roots machine, an adsorber (A) and a shut-off valve (V), the rotary machine (R) being alternately actuated, in one direction during a first phase of pressurization and of production and then, in the other direction, during a second phase of depressurization and desorption. Used particularly in the production of small and medium volumes of oxygen in modular installations.

Abstract: Process for treating a gas mixture by pressure swing adsorption wherein for each adsorber (1), the duration (T.sub.R) of the countercurrent recompression step is much less than that (T.sub.D) of the cocurrent decompression step. The process is particularly useful in the production of oxygen from atmospheric air.

Abstract: In a process of recovering oxygen-enriched gas by pressure swing adsorption with use of adsorbers (A, B) each packed with an adsorbent which selectively adsorbs nitrogen from a gas mixture mainly containing nitrogen and oxygen, recovery of remaining oxygen-enrich gas is fully carried out by pressure equalization between both adsorbers (A, B), and a vacuum pump (8) is always connected to either adsorber (A or B) for continuous evacuation of nitrogen. For this purpose, the pressure equalization between both adsorbers (A, B) is conducted at least in two steps wherein one adsorber (A or B) is pressurized, whereas the other adsorber (B or A) is pressurized, so that recovery of oxygen-enriched gas is possible until there is substantially no pressure difference between both adsorbers (A, B).

Abstract: The invention relates to an apparatus and method for controlling the pressure in a fuel tank ullage. The apparatus includes a vapor pump which withdraws vapors from the tank ullage responsive to a signal generated by a pressure sensor in communication with the ullage. The vapors are directed to a canister containing a VOC-adsorbent material where the VOC content of the vapor is removed. Non-polluting VOC-free air is vented from the canister to the atmosphere. The invention also contemplates the provision of a second canister which would accept the tank ullage vapors after the material in a first canister becomes saturated. A portion of the VOC-free air exiting the first canister is used a purge gas to regenerate the saturated material in the first canister. The operation of the multiple canisters would alternate between adsorption and regeneration until the tank ullage pressure is reduced to below a threshold level.

Abstract: Oxygen is recovered from a hot, compressed oxygen-containing gas, preferably air, by an oxygen-selective ion transport membrane system. Hot, pressurized non-permeate gas from the membrane is cooled and useful work is recovered therefrom by expansion at temperatures below the operating temperature of the membrane. The recovered work is used together with the oxygen permeate product in applications such as oxygen-enriched combustion of liquid fuels, wood pulping processes, steel production from scrap in mini-mills, and metal fabrication operations. Oxygen permeate product can be compressed utilizing a gas booster compressor driven by expansion of cooled, pressurized non-permeate gas.

Abstract: An apparatus and method for controlling the output of an oxygen concentrator wherein an oxygen concentrator indicator is comprised of an oxygen sensor monitor and circuit board which receives a gas sample from the concentrator, the oxygen concentrator indicator circuit board converts the concentration of oxygen to a DC voltage range from 0 to 1 volt corresponding to 0% to 100% oxygen. A plurality of set-point amplifiers accept the voltage and feed the voltage to a logic block where the voltage is analyzed to insure that only one of a plurality of solid state relays or switches is energized at a time. A plurality of taps on an AC motor winding are selectively energized by the solid state relays to drive the oxygen concentrator at a pre-determined rate in response to the concentration of oxygen generated by the concentrator.

Abstract: The flow rate of a nonadsorbed product gas stream from a multiple unit PSA plant can be reduced in response to a reduced product demand by isolating all units in the plant and inserting an idle step into the adsorption cycle immediately following bed equalization steps of the cycle. In a preferred embodiment, the duration of the idle step is inversely proportional to the percentage reduction in the product demand. To maintain the product gas purity at the desired level, minor adjustments of the idle step duration can be made following adjustment to the idle step in response to a change in product demand.

Abstract: A rotary valve at the inlets of a plurality of columns cyclically (1) selects first columns on a cyclic basis to receive compressed air, adsorb nitrogen and other components in the compressed air and pass oxygen and argon to a user (e.g. patient), second columns to desorb the adsorbed components in such columns and (3) third columns to equalize pressures where the first columns change progressively to the second columns and vice versa. A compressor having adjustable characteristics and regulated in an open or closed loop introduces the compressed air through the valve to the first columns to provide an adjustable air flow for obtaining a prescribed oxygen flow to the user. An indication may be provided when the compressor characteristics regulated for obtaining the prescribed oxygen flow rate are outside particular limits. The valve may have a variable speed related to the compressor flow variations to regulate the air pressure in the columns in accordance with the air flow rate into the columns.

Abstract: The process comprises a regeneration phase including a co-current depressurization step, in order to participate in the repressurization of another adsorber, a countercurrent depressurization down to the low pressure of the cycle without gas intake, and then a countercurrent elution step at the low pressure of the cycle with oxygen taken off from production. The cycle time does not exceed 20 seconds. The process is particularly application to the production of oxygen having a purity greater than 90% with flow rates of 2 to 6 liters/minute for oxygenotherapy.

Abstract: A pressure swing process for air separation to produce concentrated gaseous oxygen at an elevated pressure without the requirement of further compression of the gaseous oxygen product. The process comprises the steps of compressing the feed air to a pressure in the range of approximately 45 psig to 105 psig, preheating the feed air to each of the adsorption beds to a temperature in the range of approximately 100.degree. F. to 200.degree. F., then directing flow of the feed air cyclically into and through at least two crystalline zeolite molecular sieve adsorption beds for selectively adsorbing at least nitrogen therein. In this manner, oxygen having a purity of approximately 88% to 93% at a recovery of approximately 30% to 45% and a bed size factor in the range of 2,500 pounds to 4,000 pounds of adsorbent per ton per day of oxygen can be delivered to a receptor tank at an elevated pressure of approximately 40 psig to 100 psig.

Abstract: A pressure swing adsorption process which includes switching a plurality of adsorption columns packed with an adsorbent successively to an adsorption step, a pressure equalization step, an evacuation step, a vacuum purge step, a pressure equalization step and a repressurization step to allow a more strongly adsorbable component gas contained in a gaseous mixture to be adsorbed on the adsorbent and to separate a less strongly adsorbable component gas. The process further includes compressing the thus separated less strongly adsorbable component gas by a product gas compressor to supply it as a product gas.

Abstract: An adsorption-desorption apparatus, for storage and dispensing of a sorbable gas, wherein a carbon physical sorbent medium bearing the adsorbed gas to be selectively dispensed is delivered by pressure differential desorption and/or thermal desorption of the sorbate gas from the sorbent material. The carbon sorbent material preferably comprises a material which is characterized by a Sorbent Working Capacity, measured for arsine at 40 Torr and at 650 Torr, of at least 100 grams arsine per liter of bed of the sorbent material, e.g., a carbon sorbent material having the adsorption isotherm characteristic of curve A in FIG. 1 herein.

Abstract: Vacuum pressure swing adsorption (VPSA) processing is carried out employing a processing sequence of ten steps that serves to enhance the productive capacity thereof for air separation and other desirable applications.

Abstract: A process for the recovery of carbon monoxide from a purge gas from acetic acid synthetic containing at least carbon monoxide, nitrogen and hydrogen, wherein the purge gas (6) containing at least carbon monoxide, nitrogen and hydrogen is separated into a gas fraction (11) rich in carbon monoxide and a residual gas fraction (12, 13) rich in nitrogen and hydrogen by an adsorption process (G), preferably by a pressure change absorption process, and the gas fraction (11) rich in carbon monoxide is returned upstream of the acetic acid.

Abstract: A device for the separation of gas by adsorption, of the so-called VSA or MPSA type, comprises, between a utilization line (L) and a source (S) of gaseous mixture to be separated, at least one module (M) comprising in series a reversible rotatable machine (R), typically a Roots, an adsorber (A) and a shut-off valve (V). The rotary machine (R) is alternately actuated, in one direction during a first phase of pressurization and of production and then, in the other direction, during a second phase of depressurization and desorption. Used particularly in the production of small and medium volumes of oxygen in modular installations.

Abstract: An adsorption process and system for the selective adsorption of a more readily adsorbable component, such as nitrogen, as from air or other feed gas mixture is carried out using a composite adsorbent bed containing different adsorbent materials positioned in separate zones in which the temperature conditions favor adsorption performance of the particular adsorbent material under applicable processing conditions in each zone. A method for the selection of the adsorbent materials is based on Adsorption Figure of Merit values.

Abstract: The invention relates to a process for the separation of a mixture of oxygen and nitrogen into each of its constituents, including bringing the mixture to be separated, in an adsorption zone, into contact with a selective adsorbent for nitrogen, the adsorbent being an agglomerated zeolite exhibiting an Si/Al ratio lower than 5, a porosity of between 0.38 and 0.60 and a parameter a.sub.k of at least 0.5 s.sup.-1, the parameter a.sub.k characterizing the kinetics of adsorption of nitrogen on the adsorbent in the adsorption zone in accordance with the Linear Driving Force model, it being understood that when the adsorbent is a zeolite containing lithium its porosity can vary between 0.25 and 0.60.

Abstract: A process for separating a mixture of gases by selective adsorption, in which pressure swing is used to induce both desorption and the flow of gas through at least one simulated moving chromatographic column.

Abstract: Selective separation and recovery of gaseous components of hot waste gas of combustion containing carbon dioxide is attained by causing the hot waste gas to contact an adsorbent containing as a substantial main component thereof an inorganic solid substance exhibiting surface basicity and inducing adsorption of the gaseous components of the hot waste gas on the adsorbent and then selectively separating the adsorbed gaseous components by virtue of differences in retention time among the gaseous components on the adsorbent.

Abstract: A composite gas filtration system for removal of toxic or harmful agents from a breathable gas supply, wherein a compressor fed pressure swing adsorption unit is placed upstream of an adsorbent carbon filter unit in a gas supply line, characterized in that a plenum chamber is positioned in the gas supply line with one or more inlet orifices supplied by gas treated by the pressure swing adsorption unit, one or more exit orifices leading to the carbon filter unit, and one or more further inlet orifices supplied by gas from upstream of the pressure swing adsorption unit, wherein a device for drawing or propelling breathable gas through the plenum chamber and carbon filter from the further inlet orifices in the event of shut down of the pressure swing adsorption unit and/or compressor is provided.

Abstract: A mixed gas consisting of carbon dioxide and nitrogen is separated into the component gases by a method which comprises treating sepiolite with nitric acid, subjecting the treated sepiolite to an ion-exchange treatment thereby exchanging the cationic metal present in the treated sepiolite with Mg ions, heating the sepiolite resulting from the ion-exchange treatment, and exposing the ultimately prepared sepiolite to the mixed gas.

Abstract: A pressure swing adsorption process for the recovery of oxygen from air improves upon a prior art process by depressurizing the adsorbent bed within an adsorbent vessel to an intermediate pressure by releasing void space gas from the product end of the vessel to a low purity oxygen tank while concurrently evacuating the adsorbent vessel from the feed end. This action enables an increased speed of depressurization and a reduction of the cycle time. Further, the adsorbent bed is repressurized to an intermediate pressure from the product outlet end with gas from the low purity oxygen tank, while concurrently pressurizing the adsorbent vessel from the input feed end. This action increases the load time fraction for a feed/vacuum blower. Further, oxygen is introduced to the product end of the adsorbent bed vessel from a high purity oxygen tank (which provides product to downstream applications) while concurrently, air is introduced to the feed end of the adsorbent bed within the vessel.

Abstract: PSA process for the separation of nitrogen from a gaseous mixture containing nitrogen by selective adsorption of nitrogen from the gaseous mixture in an adsorbent mass with cyclic pressure variations. At least one nitrogen adsorption phase is carried out at high pressure and at least one nitrogen desorption phase is carried out at low pressure. The adsorbent mass is arranged in a rotating adsorber and at least 50% of the adsorbent mass is constituted by a zeolite exchanged with lithium by more than 50%.

Abstract: Large vacuum pressure swing adsorption-oxygen plants are employed with four adsorption vessels, two air compressors, two vacuum pumps and an oxygen surge tank, operated on a (two) two-bed processing system basis. One two-bed system is offset from the other by one half of one half processing cycle. Reduced power and capital cost savings are achieved.

Abstract: An improved process for the oxygen enrichment of air by vacuum swing adsorption, pressure swing adsorption or a combination thereof, wherein the improvement comprises providing at least one packing at each of the air inlet to and air outlet from the adsorber, the packing at the air inlet side of the adsorber comprising Na-Ca zeolite X with an SiO.sub.2 /Al.sub.2 O.sub.3 ratio of 2.0 to 2.5 and with a CaO/Al.sub.2 O.sub.3 ratio of 0.4 to 0.75, the ratio being dependent upon the air inlet temperature, at an air inlet temperature of 20.degree. to 30.degree. C., the CaO/Al.sub.2 O.sub.3 ratio of the Na-Ca zeolite X at the inlet zone being 0.4 to 0.6, at an air inlet temperature of 30.degree. to 40.degree. C., the CaO/Al.sub.2 O.sub.3 ratio of the Ca zeolite X at the inlet zone being 0.55 to 0.65 and at an air inlet temperature of 40.degree. to 50.degree. C., the CaO/Al.sub.2 O.sub.3 ratio of the Na-Ca zeolite X at the inlet zone being 0.6 to 0.

Abstract: A vacuum swing adsorption process for separating a feed gas mixture into a more strongly adsorbable component and a less strongly adsorbable component in a process employing two vacuum pumps and three adsorbent beds containing an adsorbent selective for the more strongly adsorbable component using countercurrent depressurization and cocurrent ambient feed repressurization simultaneous with product end to product end pressure equalization and a common-shaft machinery arrangement which allows the expansion energy contained in the countercurrent depressurization and cocurrent ambient feed repressurization streams to be recovered and utilized to reduce overall process power consumption. Addition of three valves and an expander element will also allow expansion energy in the product purge and pressure equalization streams to be recovered. Oxygen product can be recovered from air at low cost using the process.

Abstract: A process for separating components of a gas by adsorption in an enclosure (1) divided into equal tight separated compartments (27) each provided with an adsorbent material (7, 8) chosen in function of the gas to be treated and each provided for temporarily allowing the gas to be treated to be introduced and at least one chosen component of the components of this gas to be evacuated whilst the other component or components of this gas are adsorbed by the material (7, 8), which process consists in introducing the gas to be treated into one of the compartments (27) until a predetermined pressure is reached while in the next compartments (27), gas to be treated is introduced in at least one compartment (27) and the chosen component is allowed to escape, the pressure in the next compartment (27) is allowed to drop so as to obtain a partial desorption of the non chosen component or components of the gas, a purging fluid is injected in the last compartment to achieve the final desorption, and device for carrying ou

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: In a pressure swing adsorption plant for the production of oxygen enriched gas a pressure vessel contains a first bed of molecular sieve adsorbent located adjacent an outlet 4 of the vessel which has an optimum operating efficiency at approximately ambient temperature and a second bed 10 of molecular sieve adsorbent which has an optimum efficiency below that of ambient operating temperature located adjacent the inlet 2.

Abstract: Chabazite, offretite, erionite, levyne, mordenite, gmelinite, zeolite A, zeolite T, EMC-2, ZSM-3, ZSM-18, ZK-5, zeolite L, and beta zeolite whose exchangeable cations are composed of 95 to 50% lithium ions, 4 to 50% of one or more of aluminum, cerium, lanthanum and mixed lanthanides and 0 to 15% of other ions are prepared by ion-exchanging the base zeolite with water-soluble trivalent ion salts and with water soluble lithium salts. The zeolites preferentially adsorb nitrogen from gas mixtures.

Abstract: High purity argon is produced by subjecting a two-phase liquid-vapor mixture containing up to 3 volume % of nitrogen and/or up to 5 volume % oxygen to cryogenic temperature swing adsorption in an adsorption bed containing one or more adsorbents selective for nitrogen and/or oxygen at a temperature between the bubble point and the dew point of the two-phase mixture.

Abstract: The present invention is a composition, a synthesis of the composition and a method of using the composition for selectively adsorptively separating nitrogen from oxygen wherein the composition is a crystalline EMT with a Si/Al ratio less than 2.0 and a micropore volume determined in the sodium and/or potassium form of at least 0.20 cm.sup.3 /g and a lithium cation exchange of at least 80%, preferably including an intergrowth with a crystalline FAU structure, wherein the pure or intergrowth compositions have the chemical formula:M.sub.2/n O:X.sub.2 O.sub.3 :(2.0 to <4.0)SiO.sub.2wherein M=one or more metal cations having a valence of n, and X is selected from the group consisting of aluminum, gallium and boron, preferably aluminum.

Abstract: Segregated external gas storage tanks are used to store gases of varying purity for use in the purge and pressure equalization and product repressurization steps of pressure swing adsorption operations, thereby enabling the bed size factor and the power requirements of pressure swing adsorption-gas separation operations to be significantly reduced.

Abstract: The present invention is a composition, a synthesis of the composition and a method of using the composition for selectively adsorptively separating nitrogen from oxygen wherein the composition is a crystalline EMT with a Si/Al ratio less than 2.0 and a lithium cation exchange of at least 80%, preferably including an intergrowth with a crystalline FAU structure, wherein the pure or intergrowth compositions have the chemical formula:(0.2-0.0)M.sub.2/n 0:(0.80-1.0)Li.sub.2 0:X.sub.2 0.sub.3 :(2.0 to <4.0)SiO.sub.2wherein M=a metal cation other than lithium having a valence of n, and X is selected from the group consisting of aluminum, gallium and boron, preferably aluminum.

Abstract: Pressure swing adsorption of air and other gas separation operations are carried out using specific preferred zeolite adsorbent compositions based on the symmetry of the framework atoms and cations therein. Specific SiO.sub.2 /Al.sub.2 O.sub.3 and cation/cation ratios for enhanced performance are identified. LiX adsorbent having a silica to alumina ratio on the order of 2.364 provides enhanced PSA performance.

Abstract: Apparatus and a process for producing nitrogen or air containing not more than 0.5 ppm by volume of carbon monoxide. A nitrogen stream or air stream containing up to about 100 ppm by volume of carbon monoxide is subjected to cryogenic temperature swing adsorption in an adsorption bed containing calcium-exchanged type X zeolite, type 5A zeolite or 13X zeolite, which removes substantially all of the carbon monoxide from the nitrogen stream or air stream.

Abstract: In a "vacuum" type cycle, the depressurization of a first adsorber at the high pressure of the cycle is effected by placing it in communication with the outlet of a second adsorber at the low pressure of the cycle. This communication takes place simultaneously with countercurrent pumping in a first stage for the second adsorber and in a second stage for the first adsorber, the recompression to the high pressure of the cycle being effected by production gas. Used for the production of oxygen from air.

Abstract: A method for recovering argon and hydrogen simultaneously from a feed mixture comprising argon, hydrogen, methane, nitrogen, ammonia, and moisture by passing a two stage adsorption separation (PSA). The feed gas including 4-6% hydrogen is sent to the first stage PSA to obtain a product hydrogen during the first period of adsorption step, and to obtain an intermediate product of argon and hydrogen mixture during the next period of adsorption step. The adsorbed gases are evacuated and sent to fuel gas. The intermediate product argon and hydrogen mixture is sent to the second stage adsorption bed. The effluent of adsorption step is recovered as another product hydrogen. After the adsorption step, the second stage adsorber is undergone concurrent blowdown, pressure equalization, argon recovery, argon purge, desorption production of argon, pressure equalization, pressurization with product hydrogen. Through such cyclic operation of two-stage PSA, high purity argon and hydrogen are recovered simultaneously.

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.