Abstract: An electronic controller (16) controls the operation of an electrochemical oxygen generating system (14) producing a desired gas. The product gas is fed to a storage unit (12) or a regulator (28) and pulsing valve (28) controlling the gas flow to a user. A two-stage system (180) combines a low pressure 100 and a high pressure (150) gas generating subsystems. The low pressure subsystem (100) uses IMAT's (106) to pump oxygen from ambient air to generate a low-pressure. The high pressure subsystem (150) uses IMAT's (160) to pump oxygen to high-pressure oxygen storage devices (194).

Abstract: A process for selectively separating hydrogen from at least one more strongly adsorbable component in a plurality of adsorption beds to produce a hydrogen-rich product gas from a low hydrogen concentration feed with a high recovery rate. Each of the plurality of adsorption beds subjected to a repetitive cycle. The process comprises an adsorption step for producing the hydrogen-rich product from a feed gas mixture comprising 5% to 50% hydrogen, at least two pressure equalization by void space gas withdrawal steps, a provide purge step resulting in a first pressure decrease, a blowdown step resulting in a second pressure decrease, a purge step, at least two pressure equalization by void space gas introduction steps, and a repressurization step. The second pressure decrease is at least 2 times greater than the first pressure decrease.

Abstract: Process step in a pressure swing adsorption process using multiple parallel adsorbent beds operating in cyclic process steps to recover a less strongly adsorbable component from a feed gas mixture containing at least one less strongly adsorbable component and at least one more strongly adsorbable component, wherein each adsorbent bed has a feed end and a product end, wherein each bed is subjected to at least a feed/product step, one or more depressurization steps, a purge step in which a purge gas enriched in the less strongly adsorbable component is introduced into the product end of the bed and a purge effluent gas is withdrawn from the feed end of the bed, and one or more repressurization steps. The process step comprises introducing at least a portion of the purge effluent gas from a first bed into the feed end of a second adsorbent bed at any time other than during the feed/product step in the second adsorbent bed.

Abstract: The present invention relates generally to processes and systems for recovering helium from low helium-containing feed gases (i.e., containing less than about 10 volume % helium and more typically, less than about 5 % helium by volume). The present invention more particularly relates to processes and systems for recovering helium from low helium-containing feed gases using temperature swing adsorption (TSA) systems and multiple (e.g. two) stage vacuum pressure swing adsorption (VPSA) systems. In preferred embodiments of the invention, the first stage VPSA system is configured to provide regeneration gas for the TSA system, and/or the VPSA second stage tail gas is recycled to the first stage VPSA system.

Abstract: The present invention relates to a process for the separation of gases which comprises putting a mixture of gases in contact with a zeolite of the ESV type to obtain the selective adsorption of at least one of the gases forming the gaseous mixture. The present invention also relates to particular zeolitic compositions suitable as adsorbents.

Abstract: The present invention generally relates to vacuum pressure swing adsorption (VPSA) processes and apparatus to recover carbon dioxide having a purity of approximately ?80 mole percent from streams containing at least carbon dioxide and hydrogen (e.g., syngas). The feed to the CO2 VPSA can be at super ambient pressure. The CO2 VPSA unit produces two streams, a H2-enriched stream and a CO2 product stream. The process cycle steps are selected such that there is minimal or no hydrogen losses from the process. The recovered CO2 can be further upgraded, sequestered or used in applications such as enhanced oil recovery (EOR).

Abstract: A gas separation method for separating a specific component gas from a mixed gas using an adsorbent comprises (1) a contact step of bringing a mixed gas into a vessel to contact at a first pressure the mixed gas with an adsorbent whose adsorption property with respect to a specific component gas exhibits hysteresis, (2) a decompression step of decompressing the mixed gas in the vessel to a second pressure which is lower than the first pressure and which is within the hysteresis range, and (3) a desorption step of causing adsorbed matter to detach by placing the adsorbent at a third pressure which is lower than the second pressure and which is outside of the hysteresis range and/or by heating the adsorbent.

Abstract: The present invention is a method for operating a rapid cycling pressure swing adsorption (RCPSA) having a cycle time, T, to separate a feed gas into a non-adsorbed gas and tail gas. The method includes the steps of passing the feed gas having a purity of F % at high pressure into a first end of a bed which selectively adsorbs the tail gas and passes the product gas out a second end of the bed for a time, F. The product gas has a purity, P %, and a rate of recovery of R %. Then the bed is cocurrently depressurized for a time, tCO, followed by countercurrently depressurizing the bed for a time, tCN. The bed is then purged for a time, tP, wherein desorbate (tail gas) is released at the first end of the bed at a pressure greater than 30 psig, Subsequently the bed is repressurized for a duration, tRP. R>80%, P/F?1.1 or R?90%, 0<P/F <1.1.

Abstract: The present invention generally relates to vacuum pressure swing adsorption (VPSA) processes and apparatus to recover carbon dioxide having a purity of approximately ?90 mole % from streams containing at least carbon dioxide and hydrogen (e.g., syngas). The feed to the CO2 VPSA unit can be at super ambient pressure. The CO2 VPSA unit produces three streams, a H2-enriched stream, a H2-depleted stream and a CO2 product stream. When the CO2 VPSA unit is installed between an SMR/shift reactor and a H2 PSA unit, hydrogen recovery is expected to be increased by extracting CO2, thereby increasing hydrogen partial pressure in the H2 PSA feed. The recovered CO2 can be further upgraded, sequestered or used in applications such as enhanced oil recovery (EOR).

Abstract: Method of operating a pressure swing adsorption system having a plurality of parallel adsorber vessels and a plurality of valves and gas manifolds adapted to introduce gas into each adsorber vessel and withdraw gas from each adsorber vessel in a cyclic series of sequential process steps. A leaking valve may be identified by (1) determining a value of an operating parameter that is a function of the mass of gas provided to a receiving adsorber vessel or withdrawn from an adsorber vessel during a selected process step, portion of a process step, or series of process steps; (2) determining the deviation of the value of the operating parameter from a predetermined reference value; and (3) using the magnitude and direction of the deviation to determine whether any valves are leaking.

Abstract: The invention provides an off-gas feeding method that supplies the off-gas discharged from a plurality of adsorption towers (A, B, C) to an off-gas consumption unit (1), when performing a pressure swing adsorption process of repeating a cycle including a plurality of steps, to enrich and separate the target gas out of a gas mixture in the adsorption towers (A, B, C) loaded with an adsorbent. The method allows at least one of the plurality of adsorption towers (A, B, C) to discharge the off-gas, in all the steps included in the cycle, so as to continue to supply the off-gas to the off-gas consumption unit (1) without interruption.

Abstract: Method for the separation of a gas mixture comprising providing a PSA system with at least one adsorber vessel containing adsorbent material that is selective for the adsorption of carbon monoxide and nitrogen, passing a feed gas mixture containing at least hydrogen and carbon monoxide and optionally containing nitrogen through the adsorbent material in a feed step and withdrawing a purified hydrogen product from the adsorber vessel, wherein the feed step has a duration or feed time period of about 30 seconds or less. The adsorbent material is characterized by any of (1) a Henry's law constant for carbon monoxide between about 2.5 and about 5.5 (mmole/g)/atm; (2) a carbon monoxide heat of adsorption between about 6.0 and about 7.5 kcal/gmole; (3) a Henry's law constant for nitrogen greater than about 1.5 (mmole/g)/atm; and (4) a selectivity of carbon monoxide to nitrogen between about 5.0 and about 8.0.

Abstract: Pressure swing adsorption (PSA) assemblies with purge control systems, and hydrogen-generation assemblies and/or fuel cell systems containing the same. The PSA assemblies are operated according to a PSA cycle to produce a product hydrogen stream and a byproduct stream from a mixed gas stream. The byproduct stream may be delivered as a fuel stream to a heating assembly, which may heat the hydrogen-producing region that produces the mixed gas stream. The PSA assemblies may be adapted to regulate the flow of purge gas utilized therein, such as according to a predetermined, non-constant profile. In some embodiments, the flow- of purge gas is regulated to maintain the flow rate and/or fuel value of the byproduct stream at or within a determined range of a threshold value, and/or to regulate the flow of purge gas to limit the concentration of carbon monoxide in a heated exhaust stream produced from the byproduct stream.

Abstract: A process for the purification of hydrogen based gas mixtures utilizing zeolite X wherein the particle size distribution of the zeolite X powder has a coefficient of variation from about 15% to about 30%.

Abstract: Pressure swing adsorption (PSA) assemblies with temperature-based breakthrough detection systems, as well as to hydrogen-generation assemblies and/or fuel cell systems containing the same, and to methods of operating the same. The detection systems are adapted to detect a measured temperature associated with adsorbent in an adsorbent bed of a PSA assembly and to control the operation of at least the PSA assembly responsive at least in part thereto, such as responsive to the relationship between the measured temperature and at least one reference temperature. The reference temperature may include a stored value, a previously measured temperature and/or a temperature measured elsewhere in the PSA assembly. In some embodiments, the reference temperature is associated with adsorbent downstream from the adsorbent from which the measured temperature is detected.

Abstract: Method for the separation of a gas mixture comprising providing a pressure swing adsorption system having a plurality of adsorber vessels, wherein each vessel has an inlet, an outlet, and a bed of particulate adsorbent material disposed therein. The adsorbent material is selective for the adsorption of one or more components from the gas mixture, and each bed of adsorbent material is characterized by a bed depth and by an average particle diameter less than about 1.3 mm. A feed step is carried out during a feed time period wherein the gas mixture is introduced into the adsorber vessel, one or more components are selectively adsorbed from the gas mixture, and a product gas is withdrawn from the adsorber vessel. The bed depth in feet times the dimensionless ratio of the empty bed residence time to the feed time period is less than about 4.

Abstract: The present invention generally relates to vacuum pressure swing adsorption (VPSA) processes and apparatus to recover carbon dioxide having a purity of approximately ?90 mole % from streams containing at least carbon dioxide and hydrogen (e.g., syngas). The feed to the CO2 VPSA unit can be at super ambient pressure. The CO2 VPSA unit produces three streams, a H2-enriched stream, a H2-depleted stream and a CO2 product stream. When the CO2 VPSA unit is installed between an SMR/shift reactor and a H2 PSA unit, hydrogen recovery is expected to be increased by extracting CO2, thereby increasing hydrogen partial pressure in the H2 PSA feed. The stream from the CO2 VPSA unit, normally used as fuel, is recycled as feed to increase CO2 recovery. The recovered CO2 can be further upgraded, sequestered or used in applications such as enhanced oil recovery (EOR).

Abstract: Pressure swing adsorption system comprising two or more vessels, each having a feed end, a product end, and adsorbent material adapted to adsorb one or more components from a multi-component feed gas mixture; piping adapted to (1) introduce the feed gas mixture into the feed ends, withdraw a product gas from the product ends, and withdraw a waste gas from the feed ends of the vessels, and (2) place the product ends of any pair of vessels in flow communication; a feed pipe adapted to supply the feed gas mixture to the system; a product pipe adapted to withdraw the product gas from the system; and a waste gas pipe adapted to withdraw the waste gas from the system. An indexed rotatable multi-port valve is adapted to place the product end of each vessel in sequential flow communication with the product end of each of the other vessels.

Abstract: A method of treatment of a gas mixture which contains H2, H2S and possibly of other impurities, such as hydrocarbons. The treatment method is aimed at purifying the hydrogen mixture without incurring a overall pressure loss. The method according to the invention uses a device for pressure swing adsorption where the device includes an integrated compressor. In each adsorber of the device a pressure swing cycle is carried out which includes the steps of: adsorption, decompression, purge, and repressurization.

Abstract: A gas separation method is provided in which, when separating a first component and a second component from a mixed gas containing a plurality of components by using a pressure swing adsorption method, these components can be efficiently recovered and cost reduction can be achieved. Between an adsorption step and a regeneration process step, which use a first adsorption column containing a first adsorbent on which the first component is less readily adsorbable and the second component is absorbable, and a second adsorption column containing a second adsorbent on which the first component is readily adsorbable and the second component is less readily adsorbable, an equalization depressurization step and an equalization pressurization process step, in which the pressure of the first and second adsorption columns is equalized, is carried out.

Abstract: A three-bed pressure swing adsorption system providing a constant continuous supply gas, preferably containing a hydrogen component, in a multi-step and preferably in a twelve-step, process cycle that can produce a purified gas product, preferably hydrogen, on a constant flow.

Abstract: The present invention relates a method for concentrating a gas by applying a pressure difference to an adsorbent and an apparatus therefor, and particularly, a method for producing an enriched gas in a large amount by introducing a continuous production into every step of the process focusing on productivity rather than concentration of the product gas and an apparatus therefor. The present invention relates to a method incorporating the vacuum swing adsorption method with the pressure swing adsorption method, particularly the rapid pressure swing adsorption method which can continuously produce a desired material in a depressurization step to improve recovery rate of the desired material and productivity and an apparatus therefor. The apparatus according to the present invention is advantageously applied in a small size machine rather than for industrial uses.

Abstract: Method and system on board an aircraft for the production of an oxygen-enriched gas stream from an oxygen/nitrogen gas mixture, particularly air, comprising at least one adsorber containing at least one adsorbent for adsorbing at least some of the nitrogen molecules contained in the oxygen/nitrogen feed mixture, characterized in that the adsorbent comprises a faujasite-type zeolite, having a Si/Al ratio of 1 to 1.50, exchanged to at least 80% with lithium cations. Aircraft equipped with such a system, in particular an airliner, especially an airliner of the long-range, large-capacity type.

Abstract: A valve assembly for use in a gas purification system having a plurality of vessels each having a first port opening and a second port opening. The gas purification system includes a first valve element having a first aperture to selectively connect a first port opening of a vessel to an outlet of the first valve element. The gas purification system also includes a second valve element having a second aperture to selectively connect a second port opening of a vessel to an input of the second valve element. Also provided are a motor adapted to rotate continuously and a converting mechanism that converts continuous movement of the motor into intermittent movement. The first and second valve elements are intermittently moved by the motor and the converting mechanism such that the intermittent movement changes the vessel connected to the second aperture and the vessel connected to the first aperture.

Abstract: A pressure swing adsorption process for recovering a less readily adsorbable component from a feed gas mixture comprising at least one less readily adsorbable component and at least one more readily adsorbable component. The process utilizes a plurality of adsorbent beds, each bed having a feed end and product end, wherein the process includes the gas transfer steps of (1) transferring gas from the product end of the bed to the product end of another bed; followed by (2) withdrawing waste depressurization gas from the feed end of the bed while continuing to transfer gas from the product end of the bed to the product end of another bed; (3) during either or both of (1) and (2), transferring gas from the feed end of the bed to the feed end or ends of the one or more other beds; and (4) prior to (1), transferring gas from the product end of the bed at a higher pressure to the product end of another bed at a lower pressure.

Abstract: A process is provided for recovering oxygen-rich gas by enriching gaseous oxygen contained in crude gas by a single-tank PSA process which utilizes a single adsorption tower loaded with an adsorbent. A cycle is repeated including introducing crude gas into the adsorption tower, desorbing unnecessary components from the adsorbent, introducing washing gas into the adsorption tower for discharging the remaining gas from the adsorption tower, and raising the internal pressure of the adsorption tower. The desorbing includes recovering semi-enriched oxygen gas existing in the adsorption tower after finishing of the adsorption for retention in a recovery tank. The introduction of washing gas includes introducing part of the semi-enriched oxygen gas existing in the recovery tank into the adsorption tower as the washing gas. Raising the internal pressure includes introducing the rest of the semi-enriched oxygen gas retained in the recovery tank into the adsorption tower.

Abstract: The present invention is a gas separator for separating a gas mixture into a product gas. The gas separator has an adsorbent bed including a separation chamber with first and second ports and a molecular sieve material contained in the separation chamber. A first pumping chamber is connected to the first port. A first valve regulates a flow of the gas mixture between the first port and the first pumping chamber. A first piston is located in the first pumping chamber. A second pumping chamber is connected to the second port. A second valve regulates a flow of the product gas between the second port and the second pumping chamber. A second piston is located in the second pumping chamber. A drive system coordinates operation of the first and second pistons and the first and second valves in a cycle including a pressurization stage, a gas shift stage, and a depressurization stage.

Abstract: A pressure swing adsorption process which comprises introducing a feed gas mixture into an inlet of an adsorber vessel during a feed period, wherein the feed gas mixture contains a more strongly adsorbable component and a less strongly adsorbable component and the adsorber vessel contains a bed of adsorbent material which selectively adsorbs the more strongly adsorbable component, and withdrawing a product gas enriched in the less strongly adsorbable component from an outlet of the adsorber vessel during at least a portion of the feed period, wherein a dimensionless cycle-compensated mass transfer coefficient defined as K tfeedVads/Vfeed is maintained in the range of about 23 to about 250.

Abstract: A pressure swing adsorption process wherein a constant flow of feed gas and product gas is maintained to and from a pressure swing adsorption installation. A part of repressurization is carried out by a product gas split-off, in three stages, with an additional pressure equilibration step between two adsorbers during the second of the three stages, thereby cyclically fluctuating one of the number of adsorbers receiving feed gas during some period. In addition, either combined herewith or not, in case of the use of a higher purge gas pressure, is the return to a regenerated adsorber of a least impure part of the offgas, driven by its initially higher pressure. The result is an increased product recovery efficiency and an improved flexibility of functioning of the installation.

Abstract: A method for the separation of a gas mixture comprises (a) obtaining a feed gas mixture comprising nitrogen and at least one hydrocarbon having two to six carbon atoms; (b) introducing the feed gas mixture at a temperature of about 60° F. to about 105° F. into an adsorbent bed containing adsorbent material which selectively adsorbs the hydrocarbon, and withdrawing from the adsorbent bed an effluent gas enriched in nitrogen; (c) discontinuing the flow of the feed gas mixture into the adsorbent bed and depressurizing the adsorbent bed by withdrawing depressurization gas therefrom; (d) purging the adsorbent bed by introducing a purge gas into the bed and withdrawing therefrom an effluent gas comprising the hydrocarbon, wherein the purge gas contains nitrogen at a concentration higher than that of the nitrogen in the feed gas mixture; (e) pressurizing the adsorbent bed by introducing pressurization gas into the bed; and (f) repeating (b) through (e) in a cyclic manner.

Abstract: A method to reduce the cycle time in a pressure swing adsorption process by reducing the required pressure equalization time in a cycle, thereby reducing the overall cycle time and increasing product recovery per unit of adsorbent used. This reduces the amount of adsorbent required in the beds for a given feed rate while continuing to provide product at an acceptable product purity, and has the desirable effect of reducing the capital cost of the process equipment required for a given volumetric production rate.

Abstract: A pressure swing process and system for purifying a first gas, preferably argon, from a crude feed gas stream containing the first gas and second gas(es) utilizes two adsorption beds and continuously promotes the crude feed gas to the bed during the process and simultaneous equalization of pressure in the two beds in top-to-top end and bottom-to-bottom end equalizations in each bed following purging of each bed.

Abstract: A two bed vacuum swing adsorption process for the production of oxygen is disclosed. Efficient use of air blowers and vacuum pumps maximizes the machine utilization and product gas purges in low flow and high flow modes to increase productivity while lessening power consumption.

Abstract: Gas separation by pressure swing adsorption (PSA) and vacuum pressure swing adsorption (VPSA), to obtain a purified product gas of the less strongly adsorbed fraction of the feed gas mixture, is performed with an apparatus having a plurality of adsorbers. The adsorbers cooperate with first and second valves in a rotary PSA module, with the PSA cycle characterized by multiple intermediate pressure levels between the higher and lower pressures of the PSA cycle. Gas flows enter or exit the PSA module at the immediate pressure levels as well as the higher and lower pressure levels, under substantially steady conditions of flow and pressure. The PSA module comprises a rotor containing laminated sheet adsorbers and rotating within a stator, with ported valve faces between the rotor and stator to control the timing of the flows entering or exiting the adsorbers in the rotor.

Abstract: The present invention is a gas separator for separating a gas mixture into a product gas. The gas separator has an adsorbent bed including a separation chamber with first and second ports and a molecular sieve material contained in the separation chamber. A first pumping chamber is connected to the first port. A first valve regulates a flow of the gas mixture between the first port and the first pumping chamber. A first piston is located in the first pumping chamber. A second pumping chamber is connected to the second port. A second valve regulates a flow of the product gas between the second port and the second pumping chamber. A second piston is located in the second pumping chamber. A drive system coordinates operation of the first and second pistons and the first and second valves in a cycle including a pressurization stage, a gas shift stage, and a depressurization stage.

Abstract: This invention provides a two bed pressure swing adsorption process for recovering a primary gaseous component at a purity of over 99% from a feed gas comprising the primary component and one or more impurities.

Abstract: An improved pressure swing adsorption process and system for producing a high recovery of a highly purified product gas, such as argon, from a feed gas stream containing the product gas and impurity gases employs first and second adsorption stages with beds for adsorbing impurity gases. The system and process provides for sequential steps of: feed pressurization; simultaneous feed pressurization and product pressurization; adsorption; adsorption and purge; adsorption in the absence of purge; pressure equalization between beds; evacuation and depressurization of adsorbent bed; evacuation with product purge; evacuation without purge; and pressure equalization between beds.

Abstract: There is provided, in a simple, rapid and efficient manner, a high purity, low silica X-type zeolite binderless shaped product with a high content of low silica X-type zeolite and high crystallinity, very high crush resistance and attrition resistance, and excellent adsorption performance. There is further provided an efficient gas separation method utilizing the high purity, low silica X-type zeolite binderless shaped product. With the high purity, low silica X-type zeolite binderless shaped product, the peak intensity of the faujasite zeolite at the index of 220 is stronger than the peak intensity at the index of 311 according to X-ray diffraction, and from approximately 60% to approximately 90% of the exchangeable cation sites are sodium while all or a portion of the remainder are potassium; the high purity, low silica X-type zeolite binderless shaped product also has all or a portion of the exchangeable cation sites are ion-exchanged with lithium.

Abstract: A raw gas containing a gas component A with low affinity with an adsorbent and a gas component C with high affinity with the adsorbent are sequentially supplied to at least three adsorption columns, while a desorption gas containing a gas component D which differs from the gas components A and C is supplied to each of the adsorption columns other than the one to which the raw gas is being supplied. When the raw gas is supplied to the adsorption columns, the gas component A having lower affinity with the adsorbent exits the adsorption columns earlier than the gas component C having higher affinity. The gas components A and C can thus be separated from each other. When a gas including an enriched gas component A is discharged from the outlet of each adsorption column, the full amount is extracted out of the system. When a gas including an enriched gas component C is discharged from the outlet of each adsorption column, the full amount is extracted out of the system.

Abstract: A process, especially a PSA or TSA process, for purifying a gas containing at least carbon dioxide (CO2) as impurity, in which the carbon dioxide is adsorbed on an adsorbent comprising particles of activated alumina. According to this process, the activated alumina has a specific surface area of between 200 m2/g and 299 m2/g and contains at least 80% aluminum oxide (Al2O3), silicon oxide (SiO2), iron oxide (Fe2O3) and from 0.001% to 7.25% of at least one oxide of at least one alkali or alkaline-earth metal, such as sodium and potassium oxides. According to the invention, the gas stream to be purified is air or a synthesis gas.

Abstract: A pressure swing adsorption process including an adsorption apparatus having a plurality of beds and counter-currently purging at least two of the beds simultaneously throughout the process. The number of beds and number of pressure equalization steps are not particularly limited, but a ten-bed, four pressure equalization step process in advantageous. In addition, other ten-bed, four pressure equalization step processes are disclosed which do not counter-currently purge at least two of the beds simultaneously, but which have an average of at least two of the ten beds being simultaneously regenerated by simultaneously providing off-gas from a feed end of each of the beds to an off-gas line.

Abstract: A method of separating and selectively removing hydrogen contaminant from hydrogen-containing product and by-product process streams is disclosed. Separation and removal occur when certain Cd containing zeolite, silica, alumina, carbon or clay compositions are placed in contact with a hydrogen-containing process stream. A hydrogen-encapsulated composition is formed by practice of the method. Also disclosed is a reversible storage method for hydrogen using the above-described compositions.

Abstract: A process is provided for the concentration and recovery of propylene from propane using an adsorbent comprising AlPO-14 at adsorption temperatures less than 120° C. and an adsorption pressure comprising a propylene partial pressure between about 0.5 bar and about 4 bar. The AlPO-14 adsorbent can be employed as a selective adsorbent for the separation of propylene from mixtures thereof with propane in vacuum swing adsorption processes, thermal swing adsorption processes, and combinations thereof. A simulated moving bed process using vacuum swing adsorption is used to remove propylene from a C3 hydrocarbon stream comprising propylene and propane and recover a high purity propylene product at a high recovery rate. The simulated moving bed vacuum swing adsorption process of the present invention can be employed in a variety of petroleum refining and petrochemical processes to purify and separate propylene from mixtures of propylene and propane alone or in combination with fractionation.

Abstract: A repressurization phase of an adsorber comprises a step of first countercurrent repressurization with at least gas from a first co-current decompression of another adsorber, this phase ending in a step of co-current production. Immediately following the first countercurrent repressurization step, air is introduced co-current into the adsorber.

Abstract: According to the present invention, a process is provided which overcomes historical limitations to the capacity of PSA units for a wide variety of gas separations. Capacities in excess of about 110 thousand normal cubic meters per hour (100 million standard cubic feet per day) can now be achieved in a single integrated process train. The corresponding significant equipment reduction results from a departure from the accepted principle in the PSA arts that the length of the purge step must be equal to or less than the length of the adsorption step.

Abstract: Ethene is separated from a gas mixture containing ethane by a pressure swing adsorption process carried out at a temperature in the range of about 50 to about 200° C., wherein the adsorption step of the process is conducted by passing the gas mixture through an adsorption zone containing type A zeolite whose exchangeable cations are preferably made up of at least about 60 but not more than 75% sodium ions and more than 25 and up to about 40 percent potassium ions.

Abstract: The invention comprises a pressure swing adsorption process for the separation of a less adsorbable component from a mixture comprising the less adsorbable component and a more adsorbable component, the process comprising a cyclic adsorption/desorption process wherein the desorption step is at a selected pressure and occurs for a selected time such that a pressure reducing apparatus utilized to evacuate the gas does not require extraneous cooling.

Abstract: The cycle employed is of the transatmospheric type with the use of a production buffer tank (C1), and with a purge/elution phase close to the low pressure in which gas output by another adsorber in the first cocurrent decompression phase is introduced in countercurrent into the adsorber (A, B) and, simultaneously, the countercurrent pumping is continued. During the production step, the oxygen produced is also sent into an auxiliary tank (C2), and the gas contained in this auxiliary tank is, with regard to the adsorber, used solely during a fraction of the pressurization phase of the adsorber.

Abstract: Pressure swing adsorption (PSA) separation of a gas mixture is performed in an apparatus with a plurality of adsorbent beds. The invention provides rotary multiport distributor valves to control the timing sequence of the PSA cycle steps between the beds, with flow controls cooperating with the rotary distributor valves to control the volume rates of gas flows to and from the adsorbent beds in blowdown, purge, equalization and repressurization steps.

Abstract: Pressure swing adsorption (PSA) separation of a gas mixture is performed in an apparatus with a plurality of adsorbent beds. The invention provides rotary multiport distributor valves to control the timing sequence of the PSA cycle steps between the beds, with flow controls cooperating with the rotary distributor valves to control the volume rates of gas flows to and from the adsorbent beds in blowdown, purge, equalization and repressurization steps.