Abstract: A pure vacuum swing adsorption/desorption system and method, wherein supplied air feedstock gas is consistently separated to obtain a high-purity oxygen end-product gas mixture, is described. The system and method separate high-purity oxygen product from air by sequenced adsorption and desorption operations occurring exclusively under vacuum pressure conditions. This allows for greatly reduced kilowatt-hours of electric-oxygen power consumption per oxygen ton produced.

Abstract: High product recovery and low BSF are achieved for fast-cycle shallow adsorbers in VPSA gas separation enabled by the coupled effects of high intrinsic adsorption rate and proper particle size selection.

Abstract: A carbon dioxide (CO2) adsorption membrane or bed is operative to separate metabolic CO2 from an exhaust stream from a breathable atmosphere which is discharged from a closed habitable environment. The habitable environment is in a low ambient pressure surrounding. A portion of the scrubbed exhaust gas stream is diverted from the habitable environment and passed through a desorption chamber. The desorption chamber is open to the low ambient pressure surrounding to maintain a pressure which is slightly greater than the pressure in the ambient surrounding so that the desorption chamber gas stream will exit the system into the ambient surroundings. When the diverted exhaust gas enters the low pressure desorption pressure chamber its CO2 partial pressure content is reduced. The reduced CO2 partial pressure content of the gas stream in the desorption chamber enables the desorption chamber gas stream to remove CO2 from the adsorption membrane or bed.

Abstract: A gas transfer segment of a vacuum swing adsorption process cycle utilizing multiple parallel adsorbent beds which undergo cyclic process steps to separate the components of a feed gas mixture, each bed having a feed end and a product end, wherein the gas transfer segment comprises a step of withdrawing a waste gas stream from the feed end of a first bed, withdrawing a transfer gas from the product end of the first bed and introducing the transfer gas into the product end of a second bed, and withdrawing a waste gas stream from the feed end of the second bed.

Abstract: A method for operating a pressure swing adsorption process at turndown conditions by adding selected steps to the normal design operation of the process. The selected steps include the extension of a make product/no feed step and the addition of idle steps at specific points in the process cycle during depressurization and repressurization. The average volumetric flow ratio of the pressurized feed gas to the final product gas during design operation and during turndown operation may be essentially equal. The average oxygen concentration in the final product gas during design operation and during turndown operation also may be essentially equal.

Abstract: The present invention relates to a novel family of inorganic solids with a narrow and calibrated mesopore distribution which are agglomerated with a binder; these solids can advantageously be used as adsorbents for the industrial separation of gas-phase compounds having different boiling points.

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 two stage PSA process for producing high purity oxygen from a feed air stream. Water, carbon dioxide and nitrogen are removed in a first stage. An oxygen selective adsorbent is used to adsorb oxygen in the second stage. High purity oxygen product is recovered during regeneration of the second stage. Importantly, the high purity of the oxygen product is achieved without inclusion of an oxygen rinse step in the process cycle. The high purity oxygen product is obtained by collecting the middle cut of the second stage effluent stream during regeneration.

Abstract: The present invention involves a vacuum-pressure swing adsorption process for the separation of components of a fluid mixture. The process includes (a) transferring a fluid mixture through an adsorbent bed at an elevated pressure Ph so as to produce a purified product fluid; (b) venting the adsorbent bed down to an ambient fluid pressure Pa; (c) applying a vacuum force to the adsorbent bed to bring the adsorbent bed to a reduced pressure Pl; and (d) venting the adsorbent bed up to an ambient fluid pressure Pa.

Abstract: A process for producing an oxygen enriched product includes: (a) providing a gas separation apparatus having at least one bed containing a mixture of at least two different nitrogen selective adsorbents, wherein the at least one bed is free of lithium cations; (b) feeding a feed gas containing oxygen and nitrogen into the gas separation apparatus to contact the at least one bed; and (c) recovering from the gas separation apparatus the oxygen enriched product. The process is preferably performed above ambient temperature and/or in a simplified four-step cycle.

Abstract: A compression machine (compressor 4 and/or pump 5) of the plant (1) for the treatment of a fluid, typically by pressure swing adsorption, comprises at least one detector (7) for detecting clearance between a moving part (6) and a stator and delivering a measurement signal used so as to vary, depending on this measurement, the operation of the plant and especially to automatically shorten the phases during which the machine is running at an excessively high speed.

Abstract: A process for producing an oxygen enriched product includes: (a) providing a gas separation apparatus having at least one bed containing a mixture of at least two different nitrogen selective adsorbents, wherein the at least one bed is free of lithium cations; (b) feeding a feed gas containing oxygen and nitrogen into the gas separation apparatus to contact the at least one bed; and (c) recovering from the gas separation apparatus the oxygen enriched product. The process is preferably performed above ambient temperature and/or in a simplified four-step cycle.

Abstract: A pressure swing adsorption process for the separation of a pressurized feed gas containing at least one more strongly adsorbable component and at least one less strongly adsorbable component.

Abstract: A process is provided for the concentration and recovery of propylene from propane by a pressure swing adsorption (PSA) process using an adsorbent comprising AlPO-14. A PSA process is used to remove propylene from a C3 hydrocarbon stream comprising propylene and propane. The PSA process of the present invention can be employed in petroleum refining and petrochemical processes to purify and separate propylene from mixtures of propylene and propane without fractionation.

Abstract: A gas separation system for separating a feed gas mixture into a first gas component and a second gas component comprises a stator, and a rotor rotatably coupled to the stator. The stator includes a first stator valve face, a second stator valve surface, and a plurality of function compartments opening into the stator valve surfaces. The rotor includes a first rotor valve surface in communication with the first stator valve surface, and a second rotor valve surface in communication with the second stator valve surface. The rotor also includes a plurality of rotor flow paths for receiving gas adsorbent material therein for preferentially adsorbing the first gas component in response to increasing pressure in the rotor flow paths in comparison to the second gas component. Each rotor flow path includes a pair of opposite ends opening into the rotor valve faces for communication with the function compartments.

Abstract: A VPSA apparatus includes a first adsorbent bed and a second adsorbent bed, a feed blower for providing a flow of a gas mixture at about atmospheric pressure to the beds, and a vacuum blower for removing a flow of gas therefrom and venting the gas to a space at atmospheric pressure. The VPSA process causes the first adsorbent bed to be poised for evacuation by the vacuum blower and concurrently, the second adsorbent bed is under vacuum conditions and is poised for pressurization by the feed blower. A single motor is coupled by a common shaft to both the feed blower and the vacuum blower and operates both. A conduit/valve arrangement is operative during at least a portion of a process time when the adsorbent beds are in pressurizing/evacuation states, respectively, to couple the feed blower to the second adsorbent bed when at vacuum and for concurrently coupling the vacuum blower to the first adsorbent bed which is to be evacuated.

Abstract: A vacuum swing adsorption process is provided for the separation of propylene from a feedstream comprising propylene and propane using an adsorbent comprising AlPO-14 to produce a high purity propylene product stream at high recovery. The 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 method and plant to process a fluid comprising one or more compounds G2 having a kinetic diameter less than or equal to that of nitrogen and one or more compounds G1 having a kinetic diameter greater than or equal to that of methane. The method and plant use in combination, several adsorption and desorption stages during which a first stream F1 mainly comprising compounds G1, a second stream F2 enriched in compounds G2, a third stream F3 mainly comprising compounds G2 and a fourth stream F4 mainly comprising compounds G1 are produced. At least a fraction of stream F3 is used to flush adsorption section A1.

Abstract: A low pressure swing adsorption process and apparatus for the recovery of carbon dioxide from multi-component gas mixtures, utilizing the simultaneous purge and evacuation of opposite ends of the adsorber(s) to effect controlled depressurization in the adsorber bed(s) to maintain the constant purity of a carbon dioxide-enriched product stream recovered from the adsorber inlet(s).

Abstract: Upon a reduction of the production flow rate, there is added to the cycle, at an extreme pressure PM and/or Pm of the cycle substantially different from atmospheric pressure, an idle time in the course of which the adsorber (1A, 1B) is isolated. The process is used in trans-atmospheric cycles for the production of oxygen from atmospheric air.

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 flow of gas between two vessels, each of which undergoes cyclic changes in gas pressure, is controlled by two check valves installed in parallel between the vessels. The first check valve allows gas to flow from the first vessel to the second vessel when the differential pressure between the vessels exceeds a first value, and the second check valve allows gas to flow from the second vessel to the first vessel when the differential pressure between the vessels exceeds a second value. The gas flow control method is particularly useful in pressure swing adsorption processes.

Abstract: Pressure swing adsorption separation of a feed gas mixture, to obtain a purified product gas of the less strongly adsorbed fraction of the feed gas mixture, is performed in a plurality of preferably an even number of adsorbent beds, with each adsorbent bed communicating at its product end directly to a variable volume expansion chamber, and at its feed end by directional valves to a feed compressor and an exhaust vacuum pump. For high frequency operation of the pressure swing adsorption cycle, a high surface area layered support is used for the adsorbent. The compressor and vacuum pump pistons may be integrated with the cycle, reciprocating at twice the cycle frequency. Alternative configurations of the layered adsorbent beds are disclosed.

Abstract: A PSA process and system utilizes a combination of cyclic feed, evacuation, purge, and repressurization steps to provide a final gas product enriched in one of the feed components. The process is carried out in a simple system which utilizes a single two-way four-port valve for controlling gas flow between an adsorber vessel and a blower, and the blower is used for the introduction of feed gas into the adsorber and the evacuation of gas from the adsorber. The control of gas flow in either direction between the adsorber vessel and a product gas storage tank is accomplished by two check valves installed in parallel between the vessel and the tank.

Abstract: Process and single-bed pressure swing adsorption system for separating gas mixtures, especially air. The process includes a simultaneous countercurrent product purge and partial product repressurization step which shortens cycle time and improves overall system operation.

Abstract: The strongly adsorbed component of a gas mixture is produced in enhanced purity and yield by novel PSA cycles. The basic steps of the cycles include an adsorption vessel prepressurization step, a cocurrent nonadsorbed gas production step, a cocurrent purge step with strongly adsorbed gas product and a countercurrent depressurization step which produces the strongly adsorbed gas product that is used in the cocurrent purge step. In addition to the basic steps, a first depressurization equalization step precedes or follows the cocurrent purge step and a corresponding first pressurization equalization step follows the countercurrent depressurization step. The cycle optionally includes one or two depressurization equalization steps before the cocurrent purge step and one or two corresponding pressurization equalization steps after the first pressurization equalization step.

Abstract: Pressure swing adsorption process and system for separating gas mixtures comprising at least one more strongly adsorbable component and at least one less strongly adsorbable component. The process includes storing gas enriched in one of the components in a first storage tank and a second storage tank. Final product gas is provided from the second storage tank while gas for purge, rinse, and/or repressurization is provided from the first storage tank.

Abstract: This process uses a pressure variation cycle, in which, at at least one instant in the cycle, a terminal of a compression machine (1, 3) is switched from a first space (A1) which is at a first pressure P1 to a second space (A2) which is at a pressure P2 significantly different from P1. The switching comprises an intermediate operation in which the terminal is brought simultaneously into communication with the first space and with the second space. The process is useful in the production of oxygen from atmospheric air by adsorption.

Abstract: Pressure swing adsorption process and system for separating gas mixtures comprising at least one more strongly adsorbable component and at least one less strongly adsorbable component. The process includes storing gas enriched in one of the components in a first storage tank and a second storage tank which are arranged in series. Final product gas is provided from the second storage tank while gas for purge, rinse, and/or repressurization is provided from the first storage tank.

Abstract: The device comprises an adsorber (1) and three outlet capacities (2-4), first (8, 9) and second (10, 11) structure to establish bidirectional communication between the adsorber and the elution capacity (2) and the repressurization capacity (3), respectively, and third structure (14A, 15; 16) to establish unidirectional communication from the adsorber to the production capacity (4).

Abstract: A method of treating a gaseous hydrocarbon contained in waste gas by using adsorbent layers of single-tower or multi-tower configuration is characterized in that (1) double-cylinder type or multi-cylinder type adsorption apparatus, in which each adsorbent layer is indirectly cooled by cooling water, are employed as adsorption apparatus; (2) each adsorbent layer is a packed layer of one or more kinds of materials selected from activated carbon, synthetic zeolites and hydrophobic silica gel; (3) swing time required for switching between adsorption and desorption processes is set to 1 to 15 minutes; (4) each adsorbent layer is evacuated under vacuum while being purged by using part of clean gas evacuated from each adsorbent layer and/or air in the desorption process; and (5) the gaseous hydrocarbon is recovered from outflow purge gas. This method makes it possible to prevent abnormal temperature increase within each adsorbent layer and enhance the safety of the apparatus.

Abstract: Pressure swing adsorption (PSA) separation of a feed gas mixture is performed within an apparatus having typically a single prime mover powering a feed compressor for one or multiple rotary PSA modules in parallel, each module including a rotor with a large number of angularly spaced adsorber elements, with valve surfaces between the rotor and a stator so that individual adsorber elements are opened to compartments for staged pressurization and blowdown, with thermally boosted energy recovery from staged expansion of countercurrent blowdown and light reflux gases, and a plurality of adsorber elements opened at any instant to each compartment so that each compressor and expander stage operates under substantially steady conditions of flow and pressure.

Abstract: The present invention relates to the recovery of low purity oxygen gas from the top of an adsorber vessel into a receiver tank to be used as a purge reflux gas. Recovery of void gas results in improved process efficiency. The invention may also employ a simultaneous evacuation from the top of the adsorber to remove the lower purity void gas while the main waste evacuation step is conducted. This simultaneous co-current top void gas recovery and counter-current waste evacuation from both ends of the adsorber allows for an overall increase in product recovery of between 3-5% over conventional processes.

Abstract: High purity strongly adsorbed gas, e. g., carbon monoxide, is separated from a gas mixture containing one or more other gas components, e. g., hydrogen carbon dioxide, methane, nitrogen and possibly other impurities, by a two-phase pressure swing adsorption process carried out in one or more adsorption vessels arranged in parallel and containing adsorbent which adsorbs the strongly adsorbed gas more readily than the other components of the gas mixture. The process includes two evacuation steps and two or more purge steps.

Abstract: Carbon dioxide is separated from gaseous hydrocarbons by a cyclic adsorption process using at a temperature in the range of about -50 to about 200.degree. C., wherein the adsorption step of the process is conducted by passing the gas mixture through an adsorption zone containing carbon molecular sieve or type A zeolite whose exchangeable cations are made up of about 50 to about 90% sodium ions and about 10 to about 50 percent potassium ions.

Abstract: In a process for separating a gas mixture in a pressure swing adsorption device comprising an adsorber, two outlet vessels and a rotary machine at the inlet, the rotation of the rotary machine is reversed during the first depressurization step (c-d) then during the first repressurization step (g-h), so that these first steps are each broken down into two sub-steps in which the inlet for the adsorber successively experiences two opposite flows, whereas the outlet of the adsorber experiences a flow, respectively leaving or entering, of constant direction. The process is particularly useful in the production of oxygen from air.

Abstract: A vacuum pressure swing adsorbent (VPSA) system and method for separating a component from a fluid mixture and including a fluid source for introducing the mixture into the system and a supply apparatus for collecting the separated component. A pair of adsorbent bed vessels is interposed between the fluid source and the supply apparatus to adsorb and desorb a predetermined component under respective adsorption and desorption pressures characterized by a low pressure ratio and relatively high desorption pressure values. Implementation of a single-stage vacuum device made possible by the use of the high desorption pressure, results in further reduction in both equipment and operating costs.

Abstract: A PSA process involving the storage of products of various purities in segregated storage tanks for subsequent usage is disclosed. Products of increasing purities, admitted at the product end of the bed, are used during purging and repressurization steps. In addition, different composition streams collected at the feed end of the bed during the countercurrent depressurization step are admitted at the feed end of the bed, in the order of increasing product component content, during the rising pressure step(s). This cycle gives higher recovery and lower bed size factor than prior art PSA cycles.

Abstract: In an adsorptive alternating pressure process for the enrichment of air with oxygen using a molecular sieve zeolite in an adsorber, wherein adsorbed components are desorbed under a pressure below the pressure at which air separation and N.sub.2 adsorption is effected and, after desorption, the molecular sieve adsorber is at least partly returned to the air separation pressure with oxygen gas produced in countercurrent to the air separation gas flow, the improvement which comprises cooling product gas and covering the molecular sieve adsorber with the cooled product gas.

Abstract: A process for separating the components of a gas mixture in a single adsorption vessel pressure swing adsorption system including the steps: (a) cocurrently passing the gas mixture through the adsorption vessel at a desired adsorption pressure and collecting the nonadsorbed product gas in a storage vessel, (b) cocurrently depressurizing the adsorption vessel and pumping gas removed from the adsorption vessel during this step to the storage vessel, (c) regenerating the adsorbent in the adsorption vessel by countercurrently depressurizing the adsorption vessel, and (d) repressurizing the adsorption vessel to the desired adsorption pressure. Steps (a) and (b) are carried out using gas pumping or compressing devices, and the same or different gas pumping or compressing devices can be used for steps (a) and (b). Step (c) can also be carried out with the pumping device used in step (a).

Abstract: A process and apparatus for separating the components of a gas mixture by PSA in a four-vessel adsorption system operated as two pairs of adsorption vessels. The vessels of each pair are operated 180.degree. out of phase, such that one vessel of a pair is in the adsorption mode while the other vessel of the pair is undergoing adsorbent regeneration. The apparatus includes the two pairs of adsorption vessels, an intermediate gas storage reservoir which is used to temporarily store gas removed from the nonadsorbed gas outlet end of the adsorption vessels for use in various steps of the process, one gas blower and a pair of vacuum pumps. The adsorption cycle is such that the pairs of adsorption vessels are operated out of phase relative to each other and the blower and both vacuum pumps are in continuous operation throughout the process. The process and system are particularly well adapted to the separation of nitrogen from oxygen by vacuum swing adsorption.

Abstract: High purity carbon monoxide is separated from a gas stream containing carbon monoxide, carbon dioxide, methane, hydrogen and possibly other impurities by a two-stage pressure swing adsorption process carried out in a series of adsorption vessels containing adsorbent which adsorbs carbon monoxide more readily than other components of the gas stream. The first adsorption vessel in the series is cocurrently purged with nonadsorbed product stream from the second vessel and the purge effluent from the first stage adsorption vessels is reintroduced into the first adsorption vessels as feed gas.

Abstract: In order to provide a pressure-swing-adsorption oxygen production process which can maintain the product recovery at a high level while enhancing the oxygen productivity and reducing the unit power consumption, a pressure recovery step is carried out in which communication is provided between an outlet end of an adsorption column which has completed an adsorption step and an outlet end of an adsorption column which has completed a regeneration step, and in which gas remaining in the adsorption column which has completed the adsorption step is collected within the adsorption column which has completed the regeneration step; and simultaneously with the pressure recovery step, a gas mixture which has approximately the same composition as feed gas mixture is introduced into at least one of the adsorption column which has completed the adsorption step and the adsorption column which has completed the regeneration step through the inlet end thereof.

Abstract: Substantially all of the carbon dioxide is removed from a gas containing up to about 1% by volume carbon dioxide by subjecting the gas to a pressure swing adsorption process using as the adsorbent a single layer of zeolite having a silicon to aluminum atomic ratio in the range of 1.5 to 70. The process is particularly suitable for removing substantially all carbon dioxide and water vapor contained in air prior to subjecting the air to cryogenic distillation.

Abstract: Each adsorber (1, 2) is dimensioned in such a way that it operates in substantially adiabatic mode and its production dead volume (27), which is the free volume in permanent communication with the outlet side end of the mass of adsorbent (6), is between about 10% and 60% of the volume of the mass of adsorbent. Oxygen may thus be produced from atmospheric air.

Abstract: A process for the treatment of a gaseous mixture by adsorption with variable pressure, in an adsorption installation comprising at least one adsorber. For each adsorber, there is a succession of steps defining an adsorption phase, a regeneration phase for the adsorbent comprising a depressurization step, and a pressure increase phase. The passage from one phase to the following comprises switching of at least one valve between open and closed positions. At least one valve switching is carried out according to a programmed progressive slope to control a first cocurrent decompression stage of the adsorber with transfer of gas toward a lower pressure portion of the installation. The transferred gas is sent, for at least partially balancing pressure, to another adsorber in a pressure increase phase.

Abstract: An alternating pressure apparatus for obtaining oxygen from the air has two adsorbers to which an air blower for adsorption air and a vacuum pump stand for desorption are connected. The vacuum pump stand has two vacuum pumps in tandem. In a partial load operation characterized by low O.sub.2 removal; and during the lower pressure equalization of the adsorbers, the vacuum pump stand is connected to the air blower in that in each case the vacuum valve, connecting one adsorber to the vacuum pump stand, and the air valve, connecting the same adsorber to the air blower, are opened at the same time.

Abstract: An alternating pressure apparatus for obtaining oxygen from the air has two adsorbers to which an air blower for adsorption air and a vacuum pump stand for desorption are connected. The vacuum pump stand has two vacuum pumps in tandem. The second vacuum pump in the direction of flow is configured as a rotary piston pump with preliminary inlet cooling for the defined inflow of outside air at atmospheric pressure. The inlet of the second vacuum pump is connected to the outlet of the first vacuum pump without the use of gas cooling by water injection or by a heat exchanger. The alternating pressure apparatus operates with a desorption pressure between 300 mbar and 500 mbar.