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: 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: A modular, pneumatically parallel arrangement of sieve beds for a pressure swing adsorption gas concentration apparatus is described. A manifold head structure having a plurality of ports, channels and components which are connected together forms the pneumatic circuit for the pressure swing adsorption process. The manifold structures are arranged so as to be simply connected together to modularly form a pressure swing adsorption apparatus of the desired capacity.

Abstract: In a process and installation for removing solvent vapor from exhaust air sucked from a working space, the air is fed to at least two parallel activated carbon adsorbers. Each adsorber can be switched to and fro between a charging mode in which it adsorbs solvent vapors from the exhaust air flowing through the adsorber, and a regeneration mode in which it is separated from the flow of exhaust air and flushed with water vapor and desorbed. To save energy and to reduce environmental pollution, at the end of the regeneration period each adsorber has a drying phase in which exhaust air from the working space flows through the adsorber, the air thereafter being fed to an adsorber which is operating in the charging mode.

Abstract: A vapor extraction apparatus includes a gel sorbent capable of absorbing vapor directly into the liquid state and capable of disgorging the absorbed liquid in a phase-transition. The apparatus includes a housing adapted for movement from a first position, where it is exposed to a vapor-containing gas stream and a first environmental condition, and capable of moving to a second position, where it is exposed to a second environmental condition. A gel sorbent is disposed on at least one surface of the housing. The gel sorbs vapor from the gas stream as liquid when the sorbent is in its first position. The sorbent disgorges the liquid during phase-transition collapse when it is in the second position. A method of extracting vapor from a process gas stream includes contacting a phase transition gel sorbent with vapor under conditions sufficient for the gel sorbent to undergo a phase transition and absorb vapor as liquid inside the gel sorbent.

Abstract: A pressure swing adsorption unit comprises at least two absorbers, each absorber having at least a port connectable to at least one pumping unit. The pumping unit includes a first pumping stage and a second pumping stage. Each of the pumping stages are capable of discharging into an outlet conduit. A circuit is provided for selectively and alternately connecting a port to a source of feed gas and to the pumping unit such that the first and second pumping stages are sequentially fluidly connected in parallel, and then in series to reduce the pressure at the port to an intermediate vacuum level, and then to a low vacuum level.

Abstract: The present invention is an apparatus and process for separating oxygen from air by adsorption of at least nitrogen on multiple layers of air separation adsorbent in an adsorption bed wherein the multiple layers are Na X-zeolite followed by at least another layer of adsorbent selected from the group consisting of Ca X-zeolite, Li X-zeolite, Ca A-zeolite followed by Ca X-zeolite, Ca A-zeolite followed by Li X-zeolite, Ca X-zeolite followed by Li X-zeolite, Li X-zeolite followed by Ca X-zeolite and Mg A-zeolite followed by Ca X-zeolite.

Abstract: A pressure swing adsorption process employs a simultaneous equalization and evacuation step followed by simultaneous feed and product gas repressurization steps, resulting in faster processing, and a reduction in power requirements, in the recovery of oxygen and argon from feed air.

Abstract: An improved petroleum vapor control apparatus for scrubbing petroleum vapors at high flow rates without generating dangerous levels of backpressure. The apparatus comprises a substantially air-tight housing into which petroleum vapors are ducted. The vapors are passed through an activated carbon adsorber bed having a large-diameter outlet, after which the scrubbed vapors pass into a zone of controlled pressure. The scrubbed vapors are then vented to the atmosphere. The housing is preferably able to withstand marine conditions, so that the apparatus can be used on marine barges which carry petroleum products.

Abstract: A method of separating nitrogen-enriched gas is performed by PSA with the use of an apparatus which comprises a plurality of adsorbers (1, 2), a balance tank (3), and a product receiver (4). The method is characterized by comprising the steps of (a) passing, at a predetermined flow rate, high-purity nitrogen gas from the balance tank (3) to an outlet of an adsorber (2) undergoing regeneration; (b) establishing communication between the outlets of both adsorbers (1, 2) through a pressure equalization line while opening the inlets of both adsorbers to atmospheric pressure; (c) after the above step (b), causing a predetermined amount of high-purity nitrogen gas in the balance tank (3) to reversely pass via the outlet of the adsorber (2) which is to be switched from regeneration to adsorption while also supplying the crude gas through its inlet.

Abstract: A continuous pressure driven adsorption process for separating a multi-component gaseous mixture. In accordance with the method, the multi-component gaseous mixture is passed through a first portion of the adsorbent to adsorb one or more preferentially adsorbed components while a second portion of the adsorbent is regenerated. The multi-component mixture is passed through the first portion of the adsorbent in sections and the second portion of the adsorbent is regenerated in sections. The sections forming the first portion of the adsorbent become successively less saturated and the sections forming the second portion of the adsorbent becomes successively more concentrated in the more preferentially adsorbed component. A product stream is expelled from the less saturated section of the first portion of the adsorbent. The product stream is enriched in the less preferentially adsorbed component(s).

Abstract: A nitrogen PSA system uses a back-fill step only on start-up conditions or when a minor fault has caused the plant to temporarily lose purity. The plant utilizes an oxygen analyzer which controls valves allowing the initiation and cancellation of the back-fill step.

Abstract: A vapor recovery unit comprising a vapor inlet for taking up hydrocarbon vapor from a loading facility or the like, and thereafter alternately allowing the vapor to flow to one of at least two adsorber vessels. Each adsorber vessel includes an entry port in the bottom of the adsorber vessel for receiving vapor. Hydrocarbons are retained on activated carbon beds in the adsorber vessels, resulting in purified air or other carrier gas which is removed through a discharge port also in the bottom of each adsorber vessel and released through an elevated vent to the atmosphere. Hydrocarbon vapor is desorbed from the adsorber vessel by a vacuum system and directed to a separator/absorber vessel wherein the desorbed vapor which has passed through the vacuum system is brought into contact with a hydrocarbon absorbent liquid or condenser. In use, when one adsorber vessel is taking in vapor from the vapor inlet, the other adsorber vessel is having its adsorbent bed desorbed or regenerated.

Abstract: A pressure swing adsorption apparatus including a compressor for pumping a flow of a gaseous mixture through an adsorption medium utilizes a capacity control system by which the operating capacity of the compressor can be preselected. The capacity control system is disposed upstream, i.e. on the suction side of, the compressor for limiting, when desired, the feed stream drawn into the compressor. A reduction in the operating capacity of the apparatus by way of the control system results in a corresponding reduction in the power consumption and noise levels of the compressor.

Abstract: The gas stream which emanates from landfills is treated to produce a purified gas which is essentially a hydrocarbon such as methane which can be used as the fuel source in a fuel cell power plant, or can be used in other power plants which use natural gas as a fuel. The landfill gas passes through a system which removes essentially all of the hydrogen sulfide; water; organic sulfur and halogen compounds; and solid contaminants from the gas stream. The resultant purified gas stream can be cleanly flared; used to power an energy plant; or put to other useful purposes.

Abstract: A composite semipermeable membrane comprising microporous adsorbent material supported by a porous substrate is operated in series with a pressure swing adsorption (PSA) system and the PSA reject gas is used as a sweep gas to improve membrane performance. The integrated membrane-PSA system is particularly useful for recovering high-purity hydrogen from a mixture of hydrogen and hydrocarbons, and is well-suited for integration with a steam-methane reformer.

Abstract: Pressure swing adsorption 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: In a continuous adsorption process using dual towers for separation of a multi-component feed with one tower active and the other on regeneration, automatic switching of the tower feed based on loading of a hydrogen fluoride (HF) component in the active tower is achieved by inferring HF loading based on concentration measurement of acid soluble oil (ASO). An optimum switching point, which switches tower feed near full HF capacity of the active tower but before HF breakthrough occurs, is based on calculating a second derivative for a concentration vs. time curve of ASO in the active bed effluent.

Abstract: In a regenerable collective protection system the turbine of an air cycle machine is driven by a potion of the clean air output of a pressure swing adsorber bed pair in the system. The beds in the pair are used alternately to cleanse contaminated air. They are then alternately purged of contaminant products. Valves are used to direct these alternate operations. The valve closures cause overpressures in the clean air output. The overpressures are predictable in relation to the valve actuation sequence and are removed by coordinating operation of a surge air bleed valve in the clean air output with valve actuation in the pressure swing adsorber bed pair.

Abstract: A compressed air system includes an air drying subsystem which can be configured either in an intermittent mode, in which a separate purge volume intermittently purges the desiccant used by the air drying systems when the compressor goes off load, or in a continuous flow mode, in which the purge volume is replaced by a second desiccant cartridge and the two desiccant cartridges are alternatively purged and used to dry the compressed air.

Abstract: Improved apparatus for fractionating fluid mixtures by pressure swing molecular adsorption employing a rotary distributor valve and an array of adsorber columns. The columns are, in one embodiment, contained within a product holding tank or, in another embodiment, attached to a product tank. The valve sequences to provide a quasi steady-state flow, allowing optimization of adsorption/desorption cycles, and eliminating most of the valves, switches and plumbing usually required.

Abstract: A pressure swing adsorber system includes a pneumatically driven booster compressor to increase the pressure of the output product gas. A pair of inlet valves controls feed air flow to the sieve beds and the drive cylinder of the booster compressor and are cycled so that one valve opens to pressurize one sieve bed before the other valve closes to allow the other sieve bed vent to atmosphere. During the time that both valves are open, the pressure in the two sieve beds and on opposite sides of the drive cylinder equalize and a portion of the gas in the pressurized sieve bed and drive cylinder side is captured rather than being vented to ambient. System efficiency is increased by selecting whether captured gas from the last pressurized sieve bed or drive cylinder side reaches the next to be pressurized sieve bed first.

Abstract: A mobile regeneration apparatus is provided for regenerating dryers. The regeneration apparatus may be used to regenerate single tower desiccant dryers located at natural gas vehicle refueling stations. For optimum performance, each dryer may be located upstream of a respective compressor.

Abstract: A desiccant tower receives air at its air inlet and concentrates the oxygen in this air in order to provide a gas at its gas outlet which has a concentration of oxygen exceeding the concentration of oxygen normally found in air. A bypass conduit is coupled to the desiccant tower so as to syphon off gas from the desiccant tower at a point where the gas within the desiccant tower has a concentration of oxygen which is less than the concentration of oxygen in the gas at the gas outlet of the desiccant tower. The gases at the gas outlet of the desiccant tank and in the conduit are mixed so as to produce an output gas mixture having a desired concentration of oxygen. The desired concentration of oxygen is less than a desiccant tower can ordinarily provide but greater than the concentration of oxygen normally found in air.

Abstract: An operating system for dual-sieve oxygen concentrators, as used by invalids, provides a method and apparatus for controlling the purging and release of product gas and the cycling period in response to the pressure build-up in each sieve column. The cycling period is thereby self-adjusting to changes in the capacity of the columns. Restricting flow of product gas and purge gas to the higher-pressure part of the adsorption period provides product gas of higher purity and reduces the loss of oxygen in the purge.

Abstract: A pressure swing and temperature swing adsorption system is disclosed which continuously purges contaminants such as nuclear, biological and chemical warfare agents from intake air and provides cool clean air to the crew compartment of a vehicle by progressively directing contaminated air through a first adsorption bed to clean the air, while simultaneously directing hot exhaust gases at about 600.degree. F. through a second adsorption bed for purging contaminants therefrom, while simultaneously cooling a third adsorption bed for enhancing adsorption of contaminants in the purging bed upon repeating the cycles of operation.

Abstract: A method and an apparatus for concentrating/purifying a chlorine gas are disclosed in which a pressure swing adsorption method for alternately repeating an adsorbing operation and a desorbing operation employing one or more adsorption towers packed with an adsorbent for adsorbing the chlorine gas are used to obtain a high-purity concentrated/purified chlorine gas and an exhaust gas containing virtually no chlorine gas is obtained from the chlorine gas containing impurities by terminating the adsorption operation when the rate of temperature rise near the outlet end of an adsorption tower due to adsorption of chlorine therein rises above a predetermined amount.

Abstract: A carbonate spring bath system includes a supplying device of a CO.sub.2 gas, a dissolving device of the CO.sub.2 gas into a bath water, and a bathtub. The supplying device of the CO.sub.2 gas comprises a combustor for obtaining a combustion gas including the CO.sub.2 gas, a CO.sub.2 adsorption tower connected to the combustor through a gas feed line and connected to the dissolving device through a supply line, a cooler for cooling the combustion gas prior to being fed to the CO.sub.2 adsorption tower and a heater for heating an adsorbent filled in the CO.sub.2 adsorption tower for desorbing the CO.sub.2 gas therefrom. The adsorbent capable of adsorbing the CO.sub.2 gas from the combustion gas at a relatively low adsorption temperature and of desorbing the CO.sub.2 gas therefrom at a relatively high desorption temperature. As the CO.sub.2 gas in the combustion gas is adsorbed in the CO.sub.2 adsorption tower in accordance with a thermal swing adsorption method, the CO.sub.

Abstract: A molecular sieve for an oxygen concentrator free of internal filtering elements and suitable for personal use to provide substantially pure oxygen for a medical patient to breathe, having a container formed of metal with an inlet thereto and an outlet and seamed with welded seams so as to be leak-proof to moisture and able to withstand passage of hot re-activating gas, an oxygen concentrating molecular sieve material contained within the container and having a longitudinal extent concentric with the longitudinal axis of the container, filter screens and springs contained within the container extending the full diametrical extent of the container and positioned on opposite sides of the sieve material, coaxial with the longitudinal axis of the container, the sieve material being a material re-activatable by passage therethrough of a hot gas and being sandwiched between the filter screens and springs and maintained in alignment with the longitudinal axis of the container.

Abstract: Adsorbers used to dry air frequently contain 4A or 13X molecular sieve zeolites, which are intermittently reactivated by thermal regeneration. When the air pressure in a thermally regenerated adsorber is increased, such as during start-up, after adsorbent reloading, after apparatus repair, maintenance or inspection, or after repressurization following thermal regeneration, nitrogen adsorbs preferentially relative to oxygen in activated 4A and 13X molecular sieve zeolites. This produces an oxygen-enriched, high pressure gas within the adsorber vessel which emerges immediately after the adsorber is brought on line. The oxygen-enriched, high pressure gas can cause fires, explosions, and other deleterious effects in and downstream of such adsorber vessels. This invention provides thermally regenerated air driers and air drying processes using adsorbent compositions that do not adsorb nitrogen preferentially to oxygen.

Abstract: Improved apparatus for fractionating fluid mixtures by pressure swing molecular adsorption employing a rotary distributor valve and an array of adsorber columns. The columns are, in one embodiment, contained within a product holding tank or, in another embodiment, attached to a product tank. The valve sequences to provide a quasi steady-state flow, allowing optimization of adsorption/desorption cycles, and eliminating most of the valves, switches and plumbing usually required.

Abstract: An ozone decomposing material comprises an ozone decomposing agent and a support material for supporting thereon the ozone decomposing agent by adsorption, and an ozone decomposing apparatus comprises the above ozone decomposing material and an ozone decomposing agent supply means for supplying the ozone decomposing agent to the support material, by which the ozone decomposing agent is adsorbed.

Abstract: A programmable control and operation system is applied in a swing pressure adsorption process. The system comprises a computer, a driving device, and a plurality of programmable control valve assemblies. The programmable control valve assembly comprises an operating valve with at least one cavity for sealing control, a valve core, a sealing ring, an operation device, a sealing control valve, and a valve position detector. The operation of the sealing control valve is dependent on the open or closed position of the valve and the process of opening and closing the valve. The sealing control valve feeds a sealing control medium at a pressure to the cavity for sealing the operating valve. The sealing control medium acts on the sealing ring to increase the pressure at the valve core to seal the operating valve. The control and operation system provide independent control of the sealing valve and operating valve to increase reliability and durability.

Abstract: An exhaust gas treatment apparatus, which comprises first and second gas adsorbing columns each having inlet and outlet pipes; and switch-over pipes connecting the first and second gas adsorbing columns being alternatively arranged in parallel to or in series with each other, the switch-over pipes having valves arranged therein.

Abstract: A method of spectrally sensitizing a photographic light-sensitive emulsion where a water-soluble solution, prepared by dissolving a methine dye having at least one water-soluble group in water in the presence of a "Red Shift Compound", as hereinafter defined, is added to a photographic light-sensitive emulsion to provide a photographic light-sensitive emulsion spectrally sensitized with increased sensitizing efficiency and with reduced fog. The disadvantages caused by the use of high organic solvent contents are avoided and photographic light-sensitive emulsions suitable for high-speed coating are obtained.

Abstract: New cyanine dyes derived from di-halogen-benzoxazoles and benzothiazoles are desensitizers for silver halide negative emulsions and useful electron acceptor spectral sensitizers for direct positive silver halide emulsions.

Abstract: An improved silver halide photographic light-sensitive material comprising a support having coated thereon at least one photographic emulsion layer containing a dicarbocyanine dye having two heterocyclic nuclei which are 5- or 6-membered nitrogen-containing nuclei and which are connected to each other at the carbon atom in the 2- or 4-position thereof through a pentamethine chain, which can be substituted in the meso-position, a nitrogen atom of one nitrogen-containing heterocyclic nucleus of said carbocyanine dye being substituted by a sulfo- or carboxy-containing alkyl group, and a nitrogen atom of the other nitrogen-containing heterocyclic nucleus being substituted by an aralkyl group or an aryloxyalkyl group, with the proviso that said aralkyl and aryloxyalkyl groups are not substituted by a sulfo group or a carboxyl group.

Abstract: The present invention relates to light-sensitive photographic material with a light-sensitive heavy metal compound, e.g. a silver halide, and a spectral sensitizer. The spectral sensitizer is a compound in which the radicals of a sensitizing dyestuff are covalently bonded to amino, imino, hydroxyl, mercapto, carboxylic acid or carboxylic acid amide groups of a natural hydrophilic colloid, preferably gelatin.The invention also relates to new sensitizing dyes which are dinuclear cyanine dyes or merocyanine dyes which have attached either to a heterocyclic nucleus of the dye or to its methine chain a group which is reactive with a hydrophilic colloid.

Abstract: New cyanine dyes, comprising at least one of the following nuclei (or derivatives thereof):1. 2,3,3-trimethyl-5-phenyl-sulfonyl-indolenine;2. 2,3,3-trimethyl-5-benzoyl-indolenine;3. 1-aryl or alkyl-2-phenyl-5-phenyl-sulfonyl-indole;4. 1-aryl or alkyl-2-phenyl-5-benzoyl-indole,Are desensitizers for silver halide negative emulsions and useful electron acceptor spectral sensitizers for direct positive silver halide emulsions.

Abstract: Surface sensitive photographic low pAg silver halide emulsions and elements are provided which contain (1) a photographic infrared spectral sensitizing dye having a polarographic cathodic halfwave potential more positive than about -1.20 volts, said dye being employed in the emulsion at a concentration which results in at least about 0.3 log E desensitization of a test portion of the emulsion, when the test portion of the emulsion is coated on a support, sensitometrically exposed and developed and (2) a silver complexing azaindene in an amount effective to reduce the desensitization caused by the spectral sensitizing dye. Photographic emulsions in accordance with this invention exhibit higher speeds in the spectrally sensitized region (i.e., higher minus blue speeds) than prior art surface-sensitive emulsions. In addition, use of the emulsions in accordance with this invention permits the use of higher dye concentrations and results in emulsions having excellent keeping qualities and much lower fog levels.

Abstract: A method for spectrally sensitizing a photographic light-sensitive emulsion, which comprises dissolving a photographic spectrally sensitizing dye having an amidinium ion auxochrome in an organic solvent containing a substantially water-free acid having a pKa not exceeding about 5, and adding this dye-containing acid-organic solvent solution to a light-sensitive emulsion.

Abstract: Sensitization of silver halide emulsions by merocyanines and cationic cyanines and the stability of this sensitization is improved by addition of heterocyclically substituted thioureas of the formula ##EQU1## wherein R.sup.1 is alkyl, alkenyl or arylR.sup.2 is alkyl, cycloalkyl or aryln is 0 or 1, andZ completes a 5- or 6-membered heterocyclic group, preferably one which also contains a sulfur atom.