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 rapid pressure swing adsorption oxygen concentrator is provided having a plurality of at least three sieve beds cycled in sequence such that each is pressurized during one segment of a cycle and depressurized during a plurality of segments of a cycle while the other sieve beds are being sequentially pressurized. Preferably, approximately six sieves are provided and pressurized in sequence, with each being pressurized for approximately 60.degree. of the cycle and depressurized for from about 270.degree. to 300.degree. of the cycle. Each sieve is thereby pressurized for about one to two seconds and depressurized for about five to ten seconds. By utilizing the ability of the sieve material to adsorb faster than it can desorb gas, high output of up to 96% pure oxygen results with a low sieve volume and low power consumption.

Abstract: A precolumn separator provides a method of separating a solvent from a sample for use in a gas chromatograph. The precolumn has an independent carrier gas control mechanism which allows the carrier gas to be passed through the preseparation column at a rate favorable for stripping the solvent from the sample. The solvent-laden carrier gas is then purged through a purge vent which is separate from the gas chromatograph. After a period of time which effectively permits the carrier gas to be significantly removed from the sample, the flow rate of the carrier gas is reduced to the normal operating gas flow rate and the purge vent is closed. The sample is then passed through the column to the gas chromatographic column. A second purge vent can then be directed to the purge vent inlet in the gas chromatograph. Preferably, the preseparation column is a packed column which includes a separate heating element. The heating element, in turn, can be surrounded by an air cooled jacket.

Abstract: An adsorber for purifying flue gases of a furnace includes a housing having a flue gas inlet and a flue gas outlet. The housing has an adsorption medium chamber. A fill socket extends from the top of the housing. A removal device extends from the bottom of the housing. The chamber includes substantially vertical, gas-permeable walls for delimiting the chamber at the inlet side and at the outlet side. The chamber also includes a vertical gas-permeable partition and a slanted non-gas-permeable wall. The wall at the inlet side is a louver wall extending upwardly to the level of the fill socket. The wall at the outlet side is a slotted screen connected with the slanted, non-gas-permeable wall to the fill socket. The flue gas outlet is located opposite the non-gas-permeable wall.

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: A process for producing and oxygen gas stream, an oxygen-enriched gas stream, or a reaction product stream as a permeate stream and an oxygen-depleted retentate gas stream by first separating oxygen from a feed gas stream and thereafter cooling at least the permeate stream. The production and cooling of the permeate stream occurs within a single apparatus having at least one ion transport membrane.

Abstract: An ion transport reactor and process for using same having at least one ion transport membrane with a retentate side and a permeate side, for extracting oxygen from a feed gas stream as it flows along the retentate side. A reactant gas stream is flowed along the permeate side of the ion transport tubes to react with the oxygen transported therethrough. Heat is transferred to a fluid stream flowing through the ion transport reactor while the temperature of the membrane is maintained within its operating range.

Abstract: A fluorine-containing polyimide gas separation membrane which is pinhole-free, uniform over a large area, and has a high permeability and a high separation factor .alpha. is provided. A polyimide resin is dissolved in at least one solvent selected from the group consisting of an organic solvent (A) or (B). The organic solvent (A) has a dielectric constant of 30 or less and a dipole moment of 3.0 D or less. The organic solvent (B) mainly contains an organic solvent having at least one ether bonding in the molecular unit. In the next step, the polyimide resin is dipped in a solvent (C) in order for desolvation. The solvent (C) does not dissolve the fluorine-containing polyimide resin while it is miscible with the organic solvent (A) or (B). As a result, an asymmetric gas separation membrane is formed. The fluorine-containing polyimide resin layer comprises a skin layer the thickness L.sub.1 thereof is about 40 nm and a sponge like layer the thickness L.sub.2 thereof is about 30 .mu.m.

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: 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 process for recovering at least one of CF.sub.4 and C.sub.2 F.sub.6 from a vent gas from an aluminum electrolysis cell. The process includes the steps of:(a) removing inorganic fluorides from a vent gas comprising inorganic fluorides and at least one of CF.sub.4 and C.sub.2 F.sub.6 to obtain a purified vent gas; and(b) contacting the purified vent gas with a membrane at conditions effective to obtain a retentate stream rich in at least one of CF.sub.4 and C.sub.2 F.sub.6, and a permeate stream depleted in at least one of CF.sub.4 and C.sub.2 F.sub.6.

Abstract: Apparatus and method to improve flow of fluid through an annular bed in a radial flow treatment vessel. An elongated annular baffle is disposed in the reactor adjacent the bed to impart generally U-shaped flow to the fluid either prior to entering or after it exits the bed thus achieving an overall serpentine or reverse U-shaped flow pattern as the fluid proceeds from an entry port to an exit port in the reactor. Means are provided in the baffle to permit minor amounts of fluid to bypass the generally U-shaped flow path in order to correct fluid flow maldistribution through the bed that is attributed to frictional pressure drop in the flow channels adjacent to the bed. A vessel according to the invention can be operated with fluid flow through the vessel in either direction.

Abstract: A VOC (volatile organic compounds) adsorbent material such as an alumino-silicate gel desiccant is treated with a masking agent to reduce its affinity for VOC's to a level that the material can be regenerated at a predetermined low temperature which will not desorb the masking agent. The treated adsorbent material is used to adsorb VOC's and is periodically regenerated with heated air. The treated adsorbent material may be used to adsorb VOC's from recirculated spray booth air while spraying a coating on a workpiece. Subsequent to spraying, the spray booth air is heated to above the VOC regeneration temperature to regenerate the adsorbent material and optionally to cure the applied coating. As the heated spray booth air is circulated through the adsorbent material, the previously adsorbed VOC's are desorbed. The desorbed VOC's may be destroyed by oxidizing, for example, with a catalyst.

Abstract: An improved adsorbent for ozone comprises a crystalline aluminosilicate in which at least 90% of the exchangeable cation content is in the acid form and further which contains between 0.5 and 20 wt % of one or more adsorbed components which are non-reactive with ozone. Preferably the adsorbed component is water, and the total non-framework metal content expressed as metal oxide is less than 0.4 mole %.

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 composite porous ceramic hollow fiber obtained by dipping a porous ceramic hollow fiber into a carbon precursor-forming solution, picking up and drying the dipped porous ceramic hollow fiber, heating the thus deposited carbon precursor-forming film, thereby obtaining a carbon precursor thin film, and heating the carbon precursor thin film at a carbon precursor thermal decomposition temperature, thereby forming a carbon thin film on the porous ceramic hollow fiber has a permeance about 100 to about 1,000 times as high as that of an organic thin film and a separation coefficient as high as that of the organic thin film.

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: The present invention enables the dissipation of thermal energy from a gas chromatography chamber containing a gas chromatography sample by providing the housing in two parts so that ambient air can be bled in during a creation of thermal energy with a heater and additional ambient air can be circulated in a cooling cycle. Additionally, a heat exchanger for receiving liquid nitrogen can also be included to increase the speed in which thermal energy can be dissipated.

Abstract: A pre-compression dehydration system optimizes the gas flow parameters which are essential to the performance of a radial or spherical desiccant dryer. When used in conjunction with a low pressure dryer, the system protects the desiccant bed from channeling, which can cause the gas to flow unevenly through the desiccant bed and fail to make effective contact with the desiccant. The system provides a multiple zone, or divided, desiccant bed adsorption unit to maintain a proper flow distribution as required by the demand of the air compressor and to eliminate the potential for channeling. The system may also include a controller for automatically opening and closing the port access doors of the adsorption unit to control the amount of desiccant utilized to dry the air. A thermostatically controlled precooler may be provided for cooling the ambient air prior to adsorption to insure that the temperature of the effluent air will not exceed 100.degree. F. (37.8.degree. C.

Abstract: An adsorber having an upright longitudinal extent includes two perforated parallel panels extending within the vessel formed therein and spaced apart defining an adsorbent mass chamber. The adsorbent mass is in two longitudinal parts having a first part of fine particles and a second part of larger particles. The gas to be treated is circulated horizontally between the two perforated panels. This device allows the treatment cycle to be less than 60 seconds with the same or better performance. This adsorber and process are preferably used for the separation of oxygen from air.