Carbon Dioxide Sorbed Patents (Class 95/139)
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Patent number: 6319303Abstract: In this process for purifying a gas by adsorption of a first impurity and of a second impurity, at least two main adsorbers (5A, 5B) and at least one auxiliary adsorber (6A, 6B) are used, the main adsorbers comprising a packing (8A, 8B, 9A, 9B) for adsorbing the first and second impurities. During at least a first step, the gas is purified by adsorbing the two impurities by passing through at least a first (5A, 5B) of the main adsorbers without passing through a first auxiliary adsorbers (6A, 6B), and simultaneously the second main adsorber (5A, 5B) and the or each auxiliary adsorbers (6A, 6B, 6) is regenerated in parallel, then, during a second step, at least some of the gas flow is purified by adsorption of the two impurities by passing in series through the first main adsorber (5A, 5B) and through the first auxiliary adsorber (6A, 6B). Application, for example, to the purification of air for the purpose of its distillation.Type: GrantFiled: October 24, 2000Date of Patent: November 20, 2001Assignee: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges ClaudeInventors: Alain Guillard, Patrick Le Bot
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Patent number: 6309445Abstract: Carbon dioxide is removed from gas streams comprised predominantly of gases that are less strongly adsorbed than is carbon dioxide by passing the gas stream through a bed of type X zeolite having a silicon to aluminum atomic ratio not greater than about 1.15 and at least 75% of the exchangeable cations of which are potassium ions, thereby adsorbing the carbon dioxide from the gas stream. The process is particularly advantageous when applied to the removal of low levels of carbon dioxide from gas streams at temperatures of about 0 to 80° C.Type: GrantFiled: November 18, 1999Date of Patent: October 30, 2001Assignee: The BOC Group, Inc.Inventors: Craig S. Gittleman, Adeola Florence Ojo, Frank R. Fitch, Martin Bulow, Vijay R. Balse, Philip Connolly
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Patent number: 6291232Abstract: Anaerobic digestion system and process in which the raw digester gas containing methane and other gaseous components is cooled at atmospheric pressure in the presence of a liquid to a temperature at which the other gaseous components have a substantially higher solubility in the liquid than methane and are substantially all absorbed into the liquid, leaving pure, dry methane gas. That methane gas is then used in other parts of the system, including the digester and a refrigeration system for cooling the raw gas.Type: GrantFiled: October 8, 1999Date of Patent: September 18, 2001Inventor: Herman P. Miller, III
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Patent number: 6280503Abstract: Adsorption of carbon dioxide from gas streams at temperatures in the range of 300 to 500° C. is carried out with a solid adsorbent containing magnesium oxide, preferably promoted with an alkali metal carbonate or bicarbonate so that the atomic ratio of alkali metal to magnesium is in the range of 0.006 to 2.60. Preferred adsorbents are made from the precipitate formed on addition of alkali metal and carbonate ions to an aqueous solution of a magnesium salt. Atomic ratios of alkali metal to magnesium can be adjusted by washing the precipitate with water. Low surface area adsorbents can be made by dehydration and CO2 removal of magnesium hydroxycarbonate, with or without alkali metal promotion. The process is especially valuable in pressure swing adsorption operations.Type: GrantFiled: August 6, 1999Date of Patent: August 28, 2001Assignee: Air Products and Chemicals, Inc.Inventors: Steven Gerard Mayorga, Scott Jeffrey Weigel, Thomas Richard Gaffney, Jeffrey Richard Brzozowski
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Patent number: 6273939Abstract: A process, particularly of the TSA type, for separating impurities of the nitrogen protoxide (N2O) and possibly carbon dioxide (CO2) or ethylene (C2H4) type which are contained in a gas stream, such as air. The impurities of nitrogen protoxide type are removed on a faujasite zeolite having a Si/Al ratio of 1 to 1.5 and containing from 0 to 35% of K+ cations, between 1 and 99% of Na+ cations and between 1 and 99% of Ca2+ cations, preferably at least 50% of Ca2+ cations. The separation is preferably carried out at a temperature of approximately −40° C. to +80° C., preferably at room temperature. Advantageously, the process is employed for prepurifying atmospheric air before cryogenic distillation of the air thus prepurified.Type: GrantFiled: October 20, 1999Date of Patent: August 14, 2001Assignee: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges ClaudeInventors: Cyrille Millet, Serge Moreau, Georges Kraus, Jean-Pierre Gabillard
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Publication number: 20010011500Abstract: 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.Type: ApplicationFiled: February 7, 2001Publication date: August 9, 2001Applicant: L'Air Liquide, Societe Anonyme Pour L'Etude et L'Exploitation des Procedes Georges ClaudeInventors: Frederic Despreaux, Nathalie Derive-Teuscher, Chrisian Monereau
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Patent number: 6270557Abstract: Process for separating at least carbon dioxide (CO2) contained in a gas stream, preferably air, in which at least carbon dioxide is adsorbed on a zeolite-X having a Si/Al ratio of approximately 1 to 1.5 and containing at most 35% of K+ cations, between 1 and 99% of Na+ cations and at most 99% of Ca2+ cations. This process is carried out at a temperature ranging from −40° C. to +80° C. Optionally, impurities chosen from water vapour and hydrocarbons, particularly ethylene, are also removed. The air thus purified is then capable of being cryogenically distilled.Type: GrantFiled: December 29, 1998Date of Patent: August 7, 2001Assignee: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges ClaudeInventors: Cyrille Millet, Philippe Bourgeois, Georges Kraus, Jean-Pierre Gabillard
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Publication number: 20010009125Abstract: The invention relates to a process for the purification of a gas stream containing one or more gaseous impurities from the group formed by carbon dioxide, water vapor, H2S, alcohols, S02 and C1-C8 saturated or unsaturated, linear, branched or cyclic hydrocarbons. The gas stream is brought into contact with several different porous carbon adsorbents, that is to say active carbons having different properties and characteristics. The gas is air, nitrogen, hydrogen produced by the reforming or cracking of ammonia or the cracking of alcohols or hydrocarbons, natural gas, combustion gas or fermentation gas.Type: ApplicationFiled: January 4, 2001Publication date: July 26, 2001Applicant: L' Air Liquide, societe Anonyme,Inventors: Christian Monereau, Serge Moreau
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Publication number: 20010009124Abstract: A decarbonating apparatus has a dehumidifying section for adsorbing humidity contained in waste gas and a decarbonating section for adsorbing CO2 contained in the dehumidified waste gas. The decarbonating section includes a decarbonating drum rotor loaded with a CO2 adsorbent having a honeycomb structure and arranged so as to adsorb CO2 contained in the waste gas, a heated gas supply pipe for supplying a heated gas so as to desorb CO2 adsorbed by the CO2 adsorbent, a purge gas supply pipe for supplying a purge gas so as to purge desorbed CO2, and a cooling gas supply pipe for supplying a cooling gas so as to regenerate the CO2 adsorbent. The decarbonating drum rotor is rotated to successively pass through the adsorption region, the desorption region, the purging region, and the regeneration region.Type: ApplicationFiled: January 19, 2001Publication date: July 26, 2001Inventors: Minoru Suzuki, Mitio Ishibasi, Kuninobu Ootake, Jun Imada, Hiroyuki Takagi, Hidetoshi Ueno
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Patent number: 6245127Abstract: 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).Type: GrantFiled: May 27, 1999Date of Patent: June 12, 2001Assignee: Praxair Technology, Inc.Inventors: Michael Scott Kane, Frederick Wells Leavitt, Mark William Ackley, Frank Notaro
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Patent number: 6241955Abstract: A process and apparatus for the decontamination of gaseous contaminants (especially oxygen, carbon dioxide and water vapor) from hydride gases (including their lower alkyl analogs) down to ≦100 ppb contaminant concentration are described. The critical component is a high surface area metal oxide substrate with reduced metal active sites, which in various physical forms is capable of decontaminating such gases to ≦100 ppb, ≦50 ppb or ≦10 ppb level without being detrimentally affected by the hydride gases. The surface area of the substrate will be ≧100 m2/g, and preferably 200-800 m2/g. Oxides of various metals, especially manganese or molybdenum, can be used, and mixtures of integrated oxides, or one type of oxide coated on another, may be used. The substrate is preferably retained in a hydride-gas-resistant container which is installed in a gas supply line, such as to a gas- or vapor-deposition manufacturing unit.Type: GrantFiled: October 2, 1998Date of Patent: June 5, 2001Assignee: Aeronex, Inc.Inventor: Daniel Alvarez, Jr.
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Patent number: 6238460Abstract: 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 a two layer adsorption system, wherein the first layer contains activated alumina and the second layer is a zeolite or a combination of zeolites having a silicon to aluminum atomic ratio of at least 1.5. 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.Type: GrantFiled: March 26, 1999Date of Patent: May 29, 2001Assignee: The BOC Group, Inc.Inventors: Shuguang Deng, Ravi Kumar, Martin Bülow, Frank R. Fitch, Adeola Florence Ojo, Craig S. Gittleman
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Patent number: 6228150Abstract: The invention concerns a carbon dioxide absorbent for use in anaesthesiology, in which the absorbent comprises at least one pharmaceutically acceptable hydroxide essentially free of sodium and/or potassium hydroxide and a carbon dioxide absorbingly effective amount of a compatible humectant. Calcium hydroxide is the preferred hydroxide. The humectant may be of inorganic or organic origin. The carbon dioxide absorbent of the invention may, additionally, include an effective amount of a setting agent, preferably calcium sulphate hemihydrate and/or a compatible agent for internal generation of hydrogen, preferably aluminium metal powder. The carbon dioxide absorbent of the invention is chemically inert to sevoflurane, as well as to the anaesthetics enflurane, isoflurane and desflurane.Type: GrantFiled: September 3, 1999Date of Patent: May 8, 2001Assignee: Armstrong Medical LimitedInventors: John Raymond Armstrong, James Murray
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Patent number: 6214084Abstract: Iron ore is reduced to molten iron by introducing the ore into a reactor while combusting coal with pure oxygen in the reactor. The molten iron phase, which forms at the bottom of the reactor, is stirred by injecting carbon monoxide into the molten iron. In a preferred embodiment, finely pulverized iron ore is injected with pure oxygen tangentially into a cyclone section of the furnace situated on top of a converter section, thereby causing melting and preliminary reduction of the ore to take place in the cyclone section. Primary reduction of the iron oxide occurs in the converter section of the furnace.Type: GrantFiled: May 4, 1998Date of Patent: April 10, 2001Assignee: The BOC Group, Inc.Inventors: Neeraj Saxena, Paul Alfred Sweeney, Akhilesh Kapoor
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Patent number: 6210466Abstract: 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.Type: GrantFiled: August 10, 1999Date of Patent: April 3, 2001Assignee: UOP LLCInventors: Michael Whysall, Ludovicus Jan Marie Wagemans
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Patent number: 6193785Abstract: The invention relates to a process for providing subjects with an increased oxygen supply. Prior art processes, especially diaphragm or molecular sieve technology, are used to prepare oxygen-enriched pure air (10), which is used to flood premises in a building, an “oxygenarium”. These premises are large enough for the subjects exposed to this atmosphere to have considerable freedom of movement, while at the same time it is possible for them to perform strengthening or rehabilitation exercises. The air consumed by the subjects is reprocessed and fed back into the oxygenarium with fresh outside air.Type: GrantFiled: June 29, 1998Date of Patent: February 27, 2001Inventor: Hans Joachim Huf
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Patent number: 6183539Abstract: A molecular sieve adsorbent for the purification of gas streams containing water vapor and carbon dioxide and a process for its preparation. The adsorbent is a sodium form of a low-silica faujasite having a silica to alumina ratio of about 1.8:1 to about 2.2:1, a residual content of potassium ions less than about 8.0 percent (equiv.), a low content of crystalline and amorphous admixtures and crystal sizes generally within the range of 1-4 &mgr;m, blended with a binder.Type: GrantFiled: July 1, 1998Date of Patent: February 6, 2001Assignee: Zeochem Co.Inventors: Edward J. Rode, Albert M. Tsybulevskiy
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Patent number: 6176897Abstract: 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.Type: GrantFiled: December 30, 1997Date of Patent: January 23, 2001Assignee: Questor Industries Inc.Inventor: Bowie G. Keefer
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Patent number: 6168769Abstract: A process for purifying a fluid stream contaminated with carbon dioxide is provided which comprises contacting, under conditions sufficient to substantially remove the contaminated carbon dioxide from the fluid stream which contains at least one C2-C5 olefin such as ethylene or propylene, with A mixture containing an oxygen-containing metal compound such as, for example, an alkali metal hydroxide, and an inorganic oxide compound such as, for example, silica or alumina.Type: GrantFiled: December 6, 1993Date of Patent: January 2, 2001Assignee: Phillips Petroleum CompanyInventors: Stan A. Zisman, Kerry L. Evans
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Patent number: 6143057Abstract: Adsorbent composites composed of microparticulate zeolites at least 90% of whose particles have a characteristic particle dimension not greater than about 0.6 micron and a macropore inert binder. The composites are useful for separating strongly adsorbed gas components from gas mixtures. Microparticulate type X zeolites composites are particularly useful for separating nitrogen or carbon dioxide from air.Type: GrantFiled: April 23, 1999Date of Patent: November 7, 2000Assignee: The BOC Group, Inc.Inventors: Martin Bulow, Frank R. Fitch, Adeola Florence Ojo
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Patent number: 6139604Abstract: A low energy cost process for the co-production of oxygen and nitrogen employing a fuel tube extending into the first oxygen selective ion transport membrane whereby fuel is introduced adjacent to the closed end and flows cocurrently with oxygen containing gas in the annulus and an oxygen selective ion transport membrane having a separator section and a reactor section. An oxygen-containing feedstock, typically air, is compressed and then contacts the cathode side of the separator section where a portion of the oxygen contained within the feedstock is transported to the anode side of the separator section and recovered as an oxygen product gas. Substantially the remainder of the oxygen contained within the feedstock is transported from the cathode side of the reactor section to the anode side and exothermically reacted with a fuel. Following the exothermic reaction, hot nitrogen rich product gas is expanded in a turbine to generate the power necessary to compress the feedstock.Type: GrantFiled: November 4, 1998Date of Patent: October 31, 2000Assignee: Praxair Technology, Inc.Inventors: Christian Friedrich Gottzmann, Ravi Prasad, Nitin Ramesh Keskar, James Bragdon Wulf
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Patent number: 6129780Abstract: Process and apparatus for the purification of a gaseous flow containing at least one impurity which can be carbon dioxide, water vapor and/or hydrocarbon. The impurity is adsorbed on a bed of adsorbent containing at least one adsorbent material, it being possible to use stacked adsorbent beds. Atop the uppermost bed is a layer of particulate ballast having a density greater than that of the adsorbent. The bed of ballast exerts a mechanical pressure on the subjacent adsorbent and prevents fluidization of the upper portion of the subjacent adsorbent. As a result, the rate of gas flow through the adsorbent can be increased.Type: GrantFiled: February 26, 1999Date of Patent: October 10, 2000Assignee: L'Air LiquideInventors: Cyrille Millet, Philippe Bourgeois, Georges Kraus, Jean-Pierre Gabillard
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Patent number: 6113671Abstract: A process for controlling the atmosphere in a container including the steps of passing a pressurized portion of the atmosphere serially through a plurality of separate but inter-communicating adsorbent beds which selectively adsorb water vapor, ethylene, carbon dioxide and nitrogen from the compressed atmosphere, then isolating the ethylene-selective adsorbent and desorbing ethylene therefrom, then desorbing nitrogen from the nitrogen-selective adsorbent and purging the carbon dioxide-selective bed, the ethylene-selective bed and the water vapor-selective bed with the desorbed nitrogen, and returning the purge and purged gas mixture to the container.Type: GrantFiled: May 19, 1997Date of Patent: September 5, 2000Inventor: Michael E. Garrett
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Patent number: 6113673Abstract: This invention is directed to the synthesis of high bulk density high gas absorption capacity adsorbents for gas storage applications. Specifically, this invention is concerned with novel gas absorbents with high gravimetric and volumetric gas adsorption capacities which are made from fullerene-based materials. By pressing fullerene powder into pellet form using a conventional press, then polymerizing it by subjecting the fullerene to high temperature and high inert gas pressure, the resulting fullerene-based materials have high bulk densities and high gas adsorption capacities. By pre-chemical modification or post-polymerization activation processes, the gas adsorption capacities of the fullerene-based adsorbents can be further enhanced. These materials are suitable for low pressure gas storage applications, such as oxygen storage for home oxygen therapy uses or on-board vehicle natural gas storage.Type: GrantFiled: September 16, 1998Date of Patent: September 5, 2000Assignee: Materials and Electrochemical Research (MER) CorporationInventors: Raouf O. Loutfy, Xiao-Chun Lu, Weijiong Li, Michael G. Mikhael
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Patent number: 6106593Abstract: Carbon dioxide, water, nitrous oxide and optionally ethylene are removed from a feed air stream by a temperature swing adsorption using a first adsorbent such as alumina to adsorb water, a second adsorbent such as 13X zeolite to adsorb carbon dioxide, and a third adsorbent such as binderless calcium exchanged X zeolite to adsorb nitrous oxide and optionally ethylene, prior to cryogenic separation of the purified air stream.Type: GrantFiled: October 8, 1998Date of Patent: August 22, 2000Assignee: Air Products and Chemicals, Inc.Inventors: Timothy Christopher Golden, Fred William Taylor, Leighta Maureen Johnson, Nasim Hassan Malik, Christopher James Raiswell
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Patent number: 6099621Abstract: The present invention is directed toward a composition comprising a polyamine or its polymer blend and at least one salt of an aminoacid, the salt of the aminoacid being present in an amount ranging from about 10 to 80 wt % based on the total weight of the composition. Another embodiment of the present invention comprises a membrane suitable for use in separating CO.sub.2 from gas streams containing CO.sub.2, especially H.sub.2 rich gas streams containing CO.sub.2 and CO. The membrane of this invention with polyamine shows higher CO.sub.2 selectivity and permeability than the prior membrane without polyamine.Type: GrantFiled: November 25, 1998Date of Patent: August 8, 2000Assignee: Exxon Research and Engineering CompanyInventor: W. S. Winston Ho
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Patent number: 6096934Abstract: A process for converting methane to ethane and ethylene through oxidative coupling of methane and carbon conservation has been developed. The process begins by contacting methane and an oxygen-containing stream with an oxidative coupling catalyst that is capable of reacting with carbon oxides to form a solid carbonate compound in an oxidative coupling reactor to produce an effluent containing methane, ethane, and ethylene. The solid carbonate compounds are thermally decomposed to the oxidative coupling catalyst by reaction with hot hydrogen. The oxidative coupling catalyst is then available for reuse and a stream containing hydrogen and carbon oxide by-products are produced. The stream containing hydrogen and carbon oxide by-products is contacted with a methanation catalyst in a methanation reactor to produce a stream containing methane and water. The methane is separated, dried, and recycled to the oxidative coupling reactor.Type: GrantFiled: December 9, 1998Date of Patent: August 1, 2000Assignee: UOP LLCInventor: James E. Rekoske
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Patent number: 6093379Abstract: Carbon dioxide, water, carbon monoxide and hydrogen are removed from a gas stream such as air or nitrogen by adsorbing water and carbon dioxide on a solid absorbent of alumina, or zeolite and oxiding carbon monoxide over a solid catalyst to carbon dioxide and adsorbing the resulting carbon dioxide and chemisorbing the hydrogen on the catalyst, which may be palladium on alumina.Type: GrantFiled: December 4, 1998Date of Patent: July 25, 2000Assignee: Air Products and Chemicals, Inc.Inventors: Timothy Christopher Golden, Alexander Schwarz, Thomas Hsiao-Ling Hsiung, Fred William Taylor
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Patent number: 6083301Abstract: Process for purifying an inert fluid, in particular argon or helium, with respect to at least one of its impurities nitrogen (N.sub.2), oxygen (O.sub.2), carbon dioxide (CO.sub.2), carbon monoxide (CO) and hydrocarbons, in which at least some of the impurities are removed using a first adsorbent of the X zeolite type having a silica to aluminum ratio less than or equal to 1.15, and a purified inert fluid containing at most 10 ppb, preferably at most 1 ppb of impurities is recovered.Type: GrantFiled: December 3, 1998Date of Patent: July 4, 2000Assignee: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges ClaudeInventors: Daniel Gary, Rene Lardeau
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Patent number: 6083298Abstract: A process for fabricating a gas storage and dispensing system including a dispenser container for holding a physical sorbent material having sorptive affinity for (i) a sorbable dispensing gas to be held in and subsequently selectively discharged from the dispenser container, and (ii) extraneous sorbables, in which the physical sorbent material, having extraneous sorbables sorbed thereon, is treated to desorb from the sorbent material at least part of the extraneous sorbables, prior to loading the sorbent material into a gas storage and dispensing container.Type: GrantFiled: August 31, 1998Date of Patent: July 4, 2000Assignee: Advanced Technology Materials, Inc.Inventors: Luping Wang, James V. McManus
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Patent number: 6077488Abstract: A method and apparatus for producing a clean dry air product stream. In accordance with the method and apparatus, a compressed feed air stream is introduced into one adsorption bed to adsorb moisture and carbon dioxide and to produce a first intermediate product stream. Impurities contained within the first intermediate product stream such as hydrocarbons, carbon monoxide and hydrogen are catalytically reacted to produce a second intermediate product stream that contains additional carbon dioxide and moisture produced from the catalytic reaction. The second intermediate product stream is introduced into another adsorption bed that adsorbs the additional moisture and carbon dioxide formed by the catalytic reaction to produce the clean dry air product stream. The present invention can be used alone to serve the need of supplying a clean dry air product stream. Additionally, it can be used as a prepurification unit of an air separation plant designed to produce an ultra-high purity industrial gas product.Type: GrantFiled: March 19, 1998Date of Patent: June 20, 2000Assignee: The BOC Group, Inc.Inventors: Ravi Jain, James K. Tseng
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Patent number: 6071326Abstract: The production of naphtha gas from landfill gas is preferably accomplished through a gas purification step, a catalytic conversion of methane gas to hydrogen gas, and a blending step in which various process streams are blended to produce the naphtha gas stream. The landfill gas stream is first treated through a gas purification/separation procedure to produce a substantially pure methane stream. The purified methane stream is then split into at least two portions. The first portion is fed into a hydrogen reformer and a shift reactor, where the methane gas is converted into a hydrogen-bearing stream which includes hydrogen and carbon dioxide. The second portion of the stream is preferably fed into a mixer. In the mixer, the pure methane stream, the hydrogen-bearing stream and a portion of the purified landfill gas stream are preferably blended together to form a naphtha gas stream.Type: GrantFiled: July 16, 1998Date of Patent: June 6, 2000Assignee: Ecogas CorporationInventor: Thomas Lee Hall
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Patent number: 6059858Abstract: Oxygen is removed from gas streams by subjecting the gas stream to a pressure swing adsorption process carried out at temperature in the range of 300 to 1400.degree. C. using as adsorbent a perovskite material having the structural formula A.sub.1-x M.sub.x BO.sub.3-.delta., where A is a rare earth ion, M is Na, Ca, Sr, Ba or mixtures of these, B is Co, Mn, Cr or Fe, x varies from 0.1 to 1 and .delta. is the deviation from stoichiometric composition resulting from the substitution of Sr, Ca and Ba for rare earth ions.Type: GrantFiled: October 20, 1998Date of Patent: May 9, 2000Assignee: The BOC Group, Inc.Inventors: Yue-Sheng Lin, Donald L. MacLean, Yongxian Zeng
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Patent number: 6048509Abstract: A method is provided for removing water, carbon monoxide and carbon dioxide out of a gas, such as air, by passing the gas through a packed column so that the gas sequentially contacts a catalyst consisting of platinum or palladium and at least one member selected from the group consisting of iron, cobalt, nickel, manganese, copper, chromium, tin, lead and cerium wherein the catalyst is supported on alumina containing substantially no pores having pore diameters of 110 Angstroms or less under conditions which oxidize the carbon monoxide in the gas into carbon dioxide; an adsorbent selected from the group consisting of silica gel, activated alumina, zeolite and combinations thereof under conditions in which water is adsorbed and removed from the gas and an adsorbent selected from the group consisting of calcium ion exchanged A zeolite; calcium ion exchanged X zeolite; sodium ion exchanged X zeolite and mixtures thereof under conditions which carbon dioxide is adsorbed and removed from the gas.Type: GrantFiled: May 26, 1998Date of Patent: April 11, 2000Assignee: Nippon Sanso CorporationInventors: Masato Kawai, Morimitsu Nakamura, Nobuhiro Okamura
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Patent number: 6033460Abstract: A process and composition for removing moisture from a NF.sub.3 or F.sub.2 gas wherein the gas is contacted with alumina particles coated with aluminum trifluoride. The aluminum trifluoride is formed by reacting alumina particles with an aqueous solution of hydrogen fluoride.Type: GrantFiled: April 29, 1998Date of Patent: March 7, 2000Assignee: Millipore CorporationInventor: James T. Snow
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Patent number: 6027549Abstract: The present invention is a process for adsorbing carbon dioxide from a carbon dioxide containing gas mixture comprising contacting the gas mixture with an activated carbon adsorbent having a density in the range of approximately 0.56 to 0.61 g/cc (35 to 38 lbs./ft.sup.3) and adsorbing the carbon dioxide on the activated carbon adsorbent.Type: GrantFiled: April 28, 1998Date of Patent: February 22, 2000Assignee: Air Products and Chemicals, Inc.Inventors: Timothy Christopher Golden, Thomas Stephen Farris, Wilbur Clymer Kratz, William Emil Waldron, Charles Henry Johnson
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Patent number: 6027548Abstract: The invention comprises a PSA apparatus for the separation of a heavy component from a light component in a feed stream. The apparatus includes an adsorbent bed comprising either a mixture of adsorbents or composite adsorbent particles wherein each particle comprises two or more adsorbents. At least one of the adsorbents is comparatively weak and the other is comparatively strong. Another embodiment of the invention is a PSA prepurifier having a bed of adsorbent material which comprises a mixture of, or composite adsorbent particles wherein each particle comprises at least two adsorbents, at least one of the adsorbents being comparatively strong and at least another of the adsorbents being comparatively weak.Type: GrantFiled: June 12, 1998Date of Patent: February 22, 2000Assignee: Praxair Technology, Inc.Inventors: Mark William Ackley, Alan Barnard Stewart, Gregory William Henzler, Frederick Wells Leavitt, Frank Notaro, Michael Scott Kane
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Patent number: 6024781Abstract: 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.Type: GrantFiled: April 17, 1998Date of Patent: February 15, 2000Assignee: The BOC Group, Inc.Inventors: Martin Bulow, Chang Jie Guo, Dongmin Shen, Frank R. Fitch, Arthur I. Shirley, Alberto I. La Cava, Silvia Beatriz Dougill, Jonathan Paul Brooks
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Patent number: 6015450Abstract: Methanol emissions in the CO.sub.2 vent from a synthesis gas unit in an ammonia or hydrogen plant are reduced by contacting raw synthesis gas from a low temperature shift converter with recycled stripped condensate to absorb methanol. The synthesis gas is treated in a purification unit to form the CO.sub.2 vent of reduced methanol content. The condensate from the contacting step is steam stripped to form a process steam stream suitable for feed to the reformer and a stripped process condensate stream suitable for offsites polishing, a portion of which is recycled for contacting the raw synthesis gas.Type: GrantFiled: August 13, 1998Date of Patent: January 18, 2000Assignee: The M. W. Kellogg CompanyInventors: Girish Chimanlal Joshi, Stephen Allen Noe
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Patent number: 6007606Abstract: 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.Type: GrantFiled: December 9, 1997Date of Patent: December 28, 1999Assignee: Praxair Technology, Inc.Inventors: Mohamed Safdar Allie Baksh, Frank Notaro
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Patent number: 6007603Abstract: A system for controlling the atmosphere in the container comprising a membrane separation apparatus to separate nitrogen and a second separation apparatus, adapted to separate carbon dioxide and water vapor from a gas mixture in the container. The separated nitrogen is returned to the container, as is at least a portion of the carbon dioxide and water vapor, so as to produce and/or maintain a pre-determined atmosphere composition within the container thereby to prevent spoilage of perishable products within the container.Type: GrantFiled: June 26, 1998Date of Patent: December 28, 1999Assignee: The BOC Group plcInventor: Michael E. Garrett
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Patent number: 6004378Abstract: 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.Type: GrantFiled: February 24, 1992Date of Patent: December 21, 1999Assignee: Bayer AktiengesellschaftInventors: Gerhard Reiss, Lothar Puppe
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Patent number: 6004377Abstract: SF.sub.6 gas is collected from the inside of a gas insulated machine during maintenance and inspection and is refined. Compositions of the refined SF.sub.6 gas are analyzed and confirmed to be reusable at the site. In the process of SF.sub.6 gas collecting and refining, acidic gases are neutralized and removed by a dry method using filters and the refined SF.sub.6 gas is collected in a collecting tank. In particular, after the refining, the composition of the collected SF.sub.6 gas is measured and confirmed by analysis equipment to quantitatively confirm whether or not the refined SF.sub.6 gas is reusable.Type: GrantFiled: June 16, 1998Date of Patent: December 21, 1999Assignees: Hitachi Engineering & Services Co., Ltd., Showa Denko K.K.Inventors: Shin Tamata, Toru Tsubaki, Akio Nadamura, Koji Ito, Toshio Ohi, Hiromoto Ohno
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Patent number: 5989314Abstract: A pressure swing adsorption air prepurifier is used to remove water, carbon dioxide and hydrocarbons from a feed gas stream, such as a feed air stream, passing to a cryogenic air separation plant. By the incorporation of a regenerative heat exchange as an integral part of the air prepurifier, the cooling effects of the desorption of water are stored and transferred so as to cool the incoming feed air stream passing to the adsorbent material within the air prepurifier. The productive capacity of the adsorbent material is enhanced thereby.Type: GrantFiled: December 16, 1997Date of Patent: November 23, 1999Assignee: Praxair Technology, Inc.Inventors: Herbert Raymond Schaub, Frederick Wells Leavitt
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Patent number: 5989313Abstract: A pressure swing adsorber (PSA) air prepurifier includes at least a first adsorber and a second adsorber and a controller for controlling air feed to the first adsorber and the second adsorber. The invention is a "realtime" method for controlling cycle times for each adsorber and includes the following steps. During a determined time period, flow is measured to an adsorber that is coupled to an air inlet. An actual totalized flow to the on-line adsorber is accumulated, based upon the measured flow values. During this time, air feed conditions (e.g., temperature, pressure, relative humidity) are monitored and periodically, a maximum totalized flow to the adsorber is calculated, determined, at least in part, based upon the monitored air feed conditions.Type: GrantFiled: December 19, 1997Date of Patent: November 23, 1999Assignee: Praxair Technology, Inc.Inventor: James Brian Mize
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Patent number: 5985001Abstract: A thermodynamic pressure swing adsorption cycle utilizing "loudspeaker" diaphragms or pistons which are located at the top and bottom of a column containing a bed of adsorbent. The diaphragms are vibrated out of phase with each other so as to provide a displacement wave in the gas mixture within the bed of adsorbent. In addition to this displacement wave the gas is compressed prior to upward displacement and the gas pressure is lowered before the downward displacement by way of a second set of "loudspeakers" which form the side walls of the column. The second set of loudspeakers vibrate in phase with each other and operate at the same frequency as the displacement speakers.Type: GrantFiled: May 19, 1998Date of Patent: November 16, 1999Assignee: The Boc Group PLCInventors: Michael Ernest Garrett, Alberto I. LaCava
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Patent number: 5980611Abstract: 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.Type: GrantFiled: September 25, 1997Date of Patent: November 9, 1999Assignee: The BOC Group, Inc.Inventors: Ravi Kumar, Shuguang Deng, Martin Bulow, Frank Fitch, Adeola Florence Ojo, Craig S. Gittleman
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Patent number: 5980857Abstract: A process for producing hydrogen gas by reacting steam with a gas mixture containing carbon monoxide, carbon dioxide and hydrogen to produce a hydrogen-enriched product gas and subjecting the product gas to pressure swing adsorption to produce a high purity hydrogen product and a hydrogen-depleted waste gas is improved by drying, where necessary, part of the gas mixture and subjecting the dry gas mixture to pressure swing adsorption using a carbon monoxide-selective adsorbent to produce a high purity carbon monoxide product gas and a carbon monoxide-depleted waste gas. Where the gas mixture is produced by endothermic reaction, one or both of the hydrogen-depleted waste gas and the carbon monoxide-depleted waste gas can be used as fuel to supply heat for the endothermic reaction.Type: GrantFiled: March 18, 1998Date of Patent: November 9, 1999Assignee: The Boc Group, Inc.Inventors: Akhilesh Kapoor, Yudong Chen, Simon Paul Davies, Ravi Kumar, Robert Michael Thorogood
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Patent number: 5972077Abstract: A method and apparatus for separating one constituent, especially carbon dioxide, from a fluid mixture, such as natural gas. The fluid mixture flows through an adsorbent member having an affinity for molecules of the one constituent, the molecules being adsorbed on the adsorbent member. A voltage is applied to the adsorbent member, the voltage imparting a current flow which causes the molecules of the one constituent to be desorbed from the adsorbent member.Type: GrantFiled: February 20, 1998Date of Patent: October 26, 1999Assignee: Lockheed Martin Energy Research CorporationInventors: Roddie R. Judkins, Timothy D. Burchell
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Patent number: 5968234Abstract: The present invention relates to a thermally regenerable adsorptive process for the purification of a feed air, wherein the feed air is contacted with a solid adsorbent to remove at least water and carbon dioxide, wherein, periodically, the solid adsorbent is thermally regenerated by contacting the solid adsorbent with a regeneration gas stream which is essentially free of at least water and carbon dioxide, wherein the regeneration gas is a nitrogen-enriched stream removed from an elevated pressure air separation unit fed with the purified feed air, characterized in that the removed nitrogen-enriched stream is compressed in a multiple staged compressor and that the regeneration gas is a portion of the nitrogen-enriched stream which is removed from an interstage of the multiple stage compressor and then contacted with the solid adsorbent.Type: GrantFiled: April 14, 1998Date of Patent: October 19, 1999Assignee: Air Products and Chemicals, Inc.Inventors: Dan Earl Midgett, II, David Miller Espie