Abstract: The present invention relates to a novel process for the preparation of high-purity chemicals with an extremely low particle count, such as ammonia gas, hydrogen fluoride and hydrogen chloride, which are also used as aqueous solutions in semiconductor technology the corrosive gas is enriched with an absorbent which is miscible with the gas and in which impurities present in the gas are soluble, and the gas is subsequently subjected to membrane filtration.

Abstract: A method of separating or concentrating hydrocarbon-containing gas mixtures such as hydrogen from hydrocarbons, carbon dioxide from hydrocarbons, nitrogen from hydrocarbons, and hydrocarbons from one another using a selectively permeable membrane. The method is well suited to separate hydrocarbon-containing mixtures such as those generated by petroleum refining industries, petrochemical industries, natural gas processing, and the like. The membranes exhibit extremely good resistance to plasticization by hydrocarbon components in the gas mixture under practical industrial process conditions.

Abstract: A cross-linked, supported polybenzimidazole membrane for gas separation is prepared by reacting polybenzimidazole (PBI) with the sulfone-containing crosslinking agent 3,4-dichloro-tetrahydro-thiophene-1,1-dioxide. The cross-linked reaction product exhibits enhanced gas permeability to hydrogen, carbon dioxide, nitrogen, and methane as compared to the unmodified analog, without significant loss of selectivity, at temperatures from about 20 degrees Celsius to about 400 degrees Celsius.

Abstract: A method and apparatus is disclosed for producing fluorine by providing a contained fluorine precursor source located proximate to or remotely from an adsorbent bed, optionally in a replaceable unit that may be a replaceable module comprising both the fluorine source and the adsorbent bed. Fluorine derived preferably from a nitrogen trifluoride source and used to remove deposited silicon-containing impurities in reaction chambers is reclaimed from an adsorbent bed, and made available to the reaction chamber as a supplemental fluorine source to reduce the total required amount of nitrogen trifluoride source gas. The separation column adsorbent is regenerated in cyclical intervals using a reverse flow of inert gas.

Abstract: A halide gas separating and collecting device for separating and collecting halide gas from mixed gas containing the halide gas, wherein at least first and second stage separating membrane modules are stacked in multiple stages. The method comprises: feeding the mixed gas to the inlet of the first stage separating membrane module, feeding the gas passed through the previous separating membrane module to the inlets of the second and subsequent stage separating membrane modules, recycling the gas unpassed through the second and subsequent stage separating membrane modules to the inlet of the first stage separating membrane module, and controlling the flow of gas unpassed through the first stage separating membrane module by a control valve connected to the unpassed gas outlet of the first stage separating membrane module, whereby the halide gas can be separated and collected as unpassed gas at a high density and a high collection rate.

Abstract: A cyclic process for controlling environmental emissions of volatile organic compounds (VOC) from vapor recovery in storage and dispensing operations of liquids maintains a vacuum in the storage tank ullage. In the first part of a two-part cyclic process ullage vapor is discharged through a vapor recovery system in which VOC are stripped from vented gas with a selectively gas permeable membrane. In the second part, the membrane is inoperative while gas pressure rises in the ullage. In one aspect of this invention, a vacuum is drawn in the membrane separation unit thus reducing overall VOC emissions.

Abstract: A storage device for the preservation of oxidizable materials is provided. The storage device includes a storage chamber enclosing a storage space where oxidizable materials may be placed and a differentially permeable membrane. The differentially permeable membrane allows at least one selected gas to pass therethrough while inhibiting at least oxygen from passing therethrough. The differentially permeable membrane is in fluid communication with the storage chamber such that the at least one selected gas is allowed to pass through the differentially permeable membrane flows into the storage chamber. An air mover, preferably a compressor, feeds gases to the differentially permeable membrane. A cooling element is provided for cooling the temperature within the storage chamber below that of the ambient temperature. The level of oxygen within the storage chamber is thus reduced relative to the level of oxygen in the atmosphere.

Abstract: An improved mixed matrix membrane for the separation of gases comprises polyethylene glycol, silicone rubber and activated carbon on a porous support. The membrane preferably also comprises a carbonate such as potassium carbonate. The gases which may be separated by the membrane include mixtures of oxygen and nitrogen and mixtures of carbon dioxide and nitrogen. Membranes of this design may be used in processing natural gas or other gases.

Abstract: Gas mixtures of SF6 and N2 which have been used as an insulating filler gas for underground cables can be separated by use of a membrane separation in order to recover the SF6.

Abstract: A cyclic process for controlling environmental emissions of volatile organic compounds (VOC) from vapor recovery in storage and dispensing operations of liquids maintains a vacuum in the storage tank ullage. In one of a two-part cyclic process ullage vapor is discharged through a vapor recovery system in which VOC are stripped from vented gas with a selectively gas permeable membrane. In the other part, the membrane is inoperative while gas pressure rises in the ullage. Ambient air is charged to the membrane separation unit during the latter part of the cycle.

Abstract: The invention relates to preparation and uses of novel polymeric materials, polyimide amic acid salts (PIAAS). The use of these materials for the fabrication of fluid separation membranes is further disclosed.

Abstract: A fuel storage and dispensing system is provided that is effective in reducing the emission of harmful volatile organic compounds. In accordance with one embodiment of the present invention, a fuel storage and dispensing system is provided comprising at least one storage tank, an air exhaust port, at least one fuel dispenser, a fuel dispensing nozzle, a rigid, fuel dispensing spout, a boot, a pressure relief chamber, a filter system, and at least one pump. The rigid, fuel dispensing spout further defines a non-coaxial fuel tube. The boot is configured to maintain a sufficient level of vacuum within the fuel storage and dispensing system. The boot is further configured to prevent fresh air from entering the fuel dispensing nozzle.

Abstract: An apparatus and method for decontaminating chemical and biological agents using the reactive properties of both the single atomic oxygen and the hydroxyl radical for the decontamination of chemical and biological agents. The apparatus is self contained and portable and allows for the application of gas reactants directly at the required decontamination point. The system provides for the use of ultraviolet light of a specific spectral range to photolytically break down ozone into molecular oxygen and hydroxyl radicals where some of the molecular oxygen is in the first excited state. The excited molecular oxygen will combine with water vapor to produce two hydroxyl radicals.

Abstract: A process for treating natural gas or other methane-rich gas to remove excess nitrogen. The invention relies on two-stage membrane separation, using methane-selective membranes for the first stage and nitrogen-selective membranes for the second stage. The process enables the nitrogen content of the gas to be substantially reduced, without requiring the membranes to be operated at very low temperatures.

Abstract: Processes and systems to recover at least one perfluorocompound gas from a gas mixture are provided. In one embodiment the inventive process comprises the steps of a) providing a gas mixture comprising at least one perfluorocompound gas and at least one carrier gas, the gas mixture being at a predetermined pressure; b) providing at least one glassy polymer membrane having a feed side and a permeate side; c) contacting the feed side of the at least one membrane with the gas mixture; d) withdrawing from the feed side of the membrane as a non-permeate stream at a pressure which is substantially equal to the predetermined pressure a concentrated gas mixture comprising essentially the at least one perfluorocompound gas; and e) withdrawing from the permeate side of the membrane as a permeate stream a depleted gas mixture comprising essentially the at least one carrier gas.

Abstract: A process for separating a gas from a gas mixture containing an organic compound gas or vapor by a hybrid separation combining adsorption with membrane gas separation, using membranes selective for the gas over the organic compound. The membranes use a selective layer made from a polymer having repeating units of a fluorinated cyclic structure of an at least 5-member ring, and demonstrate good resistance to plasticization by the organic components in the gas mixture under treatment.

Abstract: A process for separating nitrogen from a multicomponent gas mixture containing nitrogen and a hydrocarbon, such as natural gas or associated gas, using gas-separation membranes selective for nitrogen over the hydrocarbon. The membranes use a selective layer made from a polymer having repeating units of a fluorinated polymer, and demonstrate good resistance to plasticization by the organic components in the gas mixture under treatment, and good recovery after exposure to liquid aromatic hydrocarbons.

Abstract: A process for treating natural gas or other methane-rich gas to remove excess nitrogen and optionally excess carbon dioxide, water vapor or hydrogen sulfide. The invention relies on gas separation by membranes, using nitrogen/methane selective membranes. The membranes are characterized by having the capability to exhibit a nitrogen/methane selectivity between about 2 and 5 at a temperature higher than about −25° C. The gas may be brought to pipeline specification for nitrogen, and acid gases if present, without requiring the use of amine scrubbing or other acid gas removal technique.

Abstract: A process for treating a gas mixture containing at least an organic compound gas or vapor and a second gas, such as natural gas, refinery off-gas or air. The process uses two sequential membrane separation steps, one using membrane selective for the organic compound over the second gas, the other selective for the second gas over the organic vapor. The second-gas-selective membranes use a selective layer made from a polymer having repeating units of a fluorinated polymer, and demonstrate good resistance to plasticization by the organic components in the gas mixture under treatment, and good recovery after exposure to liquid aromatic hydrocarbons. The membrane steps can be combined in either order.

Abstract: A process for treating natural gas or other methane-rich gas to remove excess nitrogen and carbon dioxide simultaneously. The invention relies on membrane separation using nitrogen/methane and carbon dioxide/methane selective membranes. The gas can typically be brought to pipeline specification for both components, without requiring the use of amine scrubbing or other acid gas removal technique. Where water vapor or hydrogen sulfide is present in the raw gas, these contaminants may also be removed to meet pipeline specification in a single operation.

Abstract: A process for separating nitrogen from a multicomponent gas mixture containing nitrogen and a hydrocarbon, such as natural gas or associated gas, using gas-separation membranes selective for nitrogen over the hydrocarbon. The membranes use a selective layer made from a polymer having repeating units of a fluorinated polymer, and demonstrate good resistance to plasticization by the organic components in the gas mixture under treatment, and good recovery after exposure to liquid aromatic hydrocarbons.

Abstract: A PFC separation recovery method to separate and recover PFC by raising the pressure of diluted mixed gas consisting of PFC gas and diluent gas, and subsequently contacting the gas with a membrane which permeates more diluent gas than PFC gas, and to separate it into a permeable gas flow rich in diluent gas and a non-permeable gas flow rich in PFC gas; and a PFC separation recovery system therefor. Moreover, the method repeatedly separates the non-permeable gas flow into another permeable gas flow and another non-permeable gas flow by contacting the gas flow with another membrane having the same functions as those of the membrane; subsequently detecting the pressure or flow rate of the other permeable gas flow; and controlling the flow rate of the other non-permeable gas flow so as to make the pressure or flow rate constant.

Abstract: A gas separation system comprising one or more ceramic membranes is described. The system, particularly, the arrangement of the ceramic membranes and/or other polymeric membranes or PSA systems, results in maximum durability of the ceramic membranes.

Abstract: A downhole preferential hydrocarbon gas recovery system and method employ preferentially selective materials to separate the hydrocarbon gas from contaminants. According to one aspect of the invention, the preferentially selective materials are arranged in tubes with the hydrocarbon gas flowing through the tubes and the contaminants permeating out through the preferentially selective material.

Abstract: Gas mixtures of SF6 and N2, which have been used, for example, as an insulating filler gas for underground cables, for insulating-gas window panes or as a filler gas for car tires and SF6/air mixtures which have been used as a protective gas when casting magnesium can be separated if they are contacted with hydrophobic zeolites of a certain pore size as selective adsorption agent for sulfur hexafluoride. For a relatively high SF6 concentration, the mixture is preferably first subjected to a membrane separation process and the permeate is contacted with the adsorption agent. The invention also relates to an apparatus for carrying out the process. The process may also be used for separating SF6 from exhaust gases.

Abstract: Processes and systems to recover at least one perfluorocompound gas from a gas mixture are provided. In one embodiment the inventive process comprises the steps of a) providing a gas mixture comprising at least one perfluorocompound gas and at least one carrier gas, the gas mixture being at a predetermined pressure; b) providing at least once glassy polymer membrane having a feed side and a permeate side; c) contacting the feed side of the at least one membrane with the gas mixture; d) withdrawing from the feed side of the membrane as a non-permeate stream at a pressure which is substantially equal to the predetermined pressure a concentrated gas mixture comprising essentially the at least one perfluorocompound gas; and e) withdrawing from the permeate side of the membrane as a permeate stream a depleted gas mixture comprising essentially the at least one carrier gas.

Abstract: A method for purifying a minority constituent and concentrating it in a majority constituent of a gas mixture that also contains one or more other minority constituent(s) employs (i) a selective permeation step, (ii) next, a purification step, and (iii) finally a concentration step. In the selective permeation step, an initial gas mixture is passed through a membrane to yield a gas mixture that is enriched in the first minority constituent. In the purifying step, the first minority constituent is absorbed by a solid adsorbent which has a strong affinity for the first minority constituent, then following an elution step, a gas mixture that contains essentially only the majority constituent and the first minority constituent is formed.

Abstract: A process for treating natural gas or other methane-rich gas to remove excess nitrogen. The invention relies on membrane separation using methane-selective membranes, but does not require the membranes to be operated at very low temperatures. We have found that, by using a two-step membrane system design, and controlling the operating pressures for the membrane steps within certain ranges, the capital and operating costs of the process can be kept within economically acceptable limits.

Abstract: Gas mixtures of SF6 and N2 which have been used as an insulating filler gas for underground cables can be separated by use of a membrane separation in order to recover the SF6.

Abstract: Porous titanium silicate molecular sieves are produced in the form of a membrane capable of separating fluid molecular mixtures.

Abstract: A partially carbonized asymmetric hollow fiber separation membrane which is a hollow fiber separation membrane having an asymmetric structure obtained by partial carbonization of an aromatic polyimide hollow fiber separation membrane with an asymmetric structure, wherein the thickness of the aromatic polyimide hollow fiber membrane to be partially carbonized is 8-50 &mgr;m, the thickness of the hollow fiber separation membrane obtained by the carbonization is 8-45 &mgr;m, and the carbon content of the hollow fiber membrane obtained by partial carbonization is at least 1.05 times the carbon content of the aromatic polyimide hollow fiber membrane to be partially carbonized, and no greater than 90 wt %; also, a process for its production and a gas separation method employing it.

Abstract: A process for separating a gas from a gas mixture containing an organic compound gas or vapor, using gas-separation membranes selective for the gas over the organic compound. The membranes use a selective layer made from a polymer having repeating units of a fluorinated cyclic structure of an at least 5-member ring, and demonstrate good resistance to plasticization by the organic components in the gas mixture under treatment.

Abstract: A process for separating a gas from a gas mixture containing the gas and a C3+ hydrocarbon vapor, using gas-separation membranes selective for the gas over the C3+ hydrocarbon vapor. The membranes use a selective layer made from a polymer having repeating units of a fluorinated polymer, and demonstrate good resistance to plasticization by the organic components in the gas mixture under treatment, and good recovery after exposure to liquid aromatic hydrocarbons.

Abstract: An installation and a process for the recovery and/or purification of at least one portion of the nitrous oxide (N2O) contained in a flow of waste gas containing nitrous oxide and at least one other gaseous compound, in which: (a) at least one nitrous oxide portion contained in the flow of waste gas is separated by permeation, and (b) at least a portion of the gaseous nitrous oxide separated in step (a) is recovered. Preferably, the source of the flow of waste gas is an industrial unit using an industrial process giving off the waste gas, preferably a unit for the production of adipic acid, a unit for the production of nitrous oxide, a unit for the production of glycoxylic acid or a unit for the production of nitric acid.

Abstract: Fire prevention and suppression system is provided for computer cabinets and fire-hazardous containers. The equipment of the system provides low-oxygen environments at standard atmospheric pressure. The system employs an oxygen-extraction apparatus that supplies oxygen-depleted air inside an enclosed area communicating with the device. A fire-extinguishing composition is provided for continuous use in computer cabinets and fire-hazardous containers, consisting of oxygen-depleted air having oxygen content below 12%.

Abstract: Processes and systems to recover at least one perfluorocompound gas from a gas mixture are provided. In one embodiment the inventive process comprises the steps of a) providing a gas mixture comprising at least one perfluorocompound gas and at least one carrier gas, the gas mixture being at a predetermined pressure; b) providing at least one glassy polymer membrane having a feed side and a permeate side; c) contacting the feed side of the at least one membrane with the gas mixture; d) withdrawing from the feed side of the membrane as a non-permeate stream at a pressure which is substantially equal to the predetermined pressure a concentrated gas mixture comprising essentially the at least one perfluorocompound gas; and e) withdrawing from the permeate side of the membrane as a permeate stream a depleted gas mixture comprising essentially the at least one carrier gas.

Abstract: Processes and systems to recover at least one perfluorocompound gas from a gas mixture are provided. In one embodiment the inventive process comprises the steps of a) providing a gas mixture comprising at least one perfluorocompound gas and at least one carrier gas, the gas mixture being at a predetermined pressure; b) providing at least once glassy polymer membrane having a feed side and a permeate side; c) contacting the feed side of the at least one membrane with the gas mixture; d) withdrawing from the feed side of the membrane as a non-permeate stream at a pressure which is substantially equal to the predetermined pressure a concentrated gas mixture comprising essentially the at least one perfluorocompound gas; and e) withdrawing from the permeate side of the membrane as a permeate stream a depleted gas mixture comprising essentially the at least one carrier gas.

Abstract: Improved polymer blends, and polymer blend membranes having improved mechanical properties are provided by alteration of the critical solution temperature of the polymer blend spinning solution through the incorporation of organic or inorganic completing agents.

Abstract: A fuel storage system is provided including a storage tank, an exhaust port, a filter system, a primary pump, and at least one secondary pump. The storage tank includes a fuel delivery port, a fluid vent port, and a pollutant return port. The filter system includes a filter input port coupled to the fluid vent port, a fuel vapor duct, and primary and secondary filter output ports. The fuel vapor duct defines a flow path extending from the filter input port to the primary filter output port. The primary filter output port is coupled to the pollutant return port. At least a portion of the fuel vapor duct forms a permeable partition designed to pass a non-pollutant component of fluid within the fuel vapor duct through the permeable partition and designed to inhibit passage of a pollutant component of fluid within the fuel vapor duct through the partition. The secondary filter output port is partitioned from the fuel vapor duct by the air-permeable partition and is coupled to the exhaust port.

Abstract: The plant for producing a product stream includes, mounted in series, several modules adapted to perform successive and distinct elementary treatments. At least two elementary treatment modules each include at least two treatment apparatuses mounted in parallel. The plant furthermore includes a device for controlling the various treatment apparatuses as a function of the product stream desired at the outlet of the plant. The control device includes sensors for measuring at least two variables representative of the product stream, and a fuzzy logic regulator adapted for controlling, in at least two distinct treatment modules, at least two treatment apparatuses of the same module, on the basis of the same measured representative variable.

Abstract: Processes and systems to recover at least one perfluorocompound gas from a gas mixture are provided. In one embodiment the inventive process comprises the steps of a) providing a gas mixture comprising at least one perfluorocompound gas and at least one carrier gas, the gas mixture being at a predetermined pressure; b) providing at least one glassy polymer membrane having a feed side and a permeate side; c) contacting the feed side of the at least one membrane with the gas mixture; d) withdrawing from the feed side of the membrane as a non-permeate stream at a pressure which is substantially equal to the predetermined pressure a concentrated gas mixture comprising essentially the at least one perfluorocompound gas; and e) withdrawing from the permeate side of the membrane as a permeate stream a depleted gas mixture comprising essentially the at least one carrier gas.

Abstract: A CVD device A is provided which is equipped with a gas introduction part A3 having an inert gas supply part G1 for supplying a diluting inert gas and a cleaning gas supply path G2 for supplying a cleaning gas, each connected therewith, and equipped with an exhaust gas discharge part A4 for releasing an exhaust gas; an exhaust gas circulation part D1 for circulating an exhaust gas from the CVD device, a cooling part D4 for cooling down and liquefying the cleaning gas in the exhaust gas, and a recovery part 4 for recovering the cleaning gas liquefied in said cooling part D4; the diluting inert gas is composed of a gas having a boiling point lower than that of the cleaning gas; a supply part 6 for supplying a cooling inert gas having the same composition as the diluting inert gas in a liquid state, an inert gas circulation part D3 which is cooled down by heat of evaporation of the cooling inert gas, and an inert gas discharge part 7 for discharging the cooling inert gas evaporated in the inert gas circulation p

Abstract: Processes and systems to recover at least one perfluorocompound gas from a gas mixture are provided. In one embodiment the inventive process comprises the steps of a) providing a gas mixture comprising at least one perfluorocompound gas and at least one carrier gas, the gas mixture being at a predetermined pressure; b) providing at least one glassy polymer membrane having a feed side and a permeate side; c) contacting the feed side of the at least one membrane with the gas mixture; d) withdrawing from the feed side of the membrane as a non-permeate stream at a pressure which is substantially equal to the predetermined pressure a concentrated gas mixture comprising essentially the at least one perfluorocompound gas; and e) withdrawing from the permeate side of the membrane as a permeate stream a depleted gas mixture comprising essentially the at least one carrier gas.

Abstract: A method for enhancing gas or oil production by delivering a nitrogen rich gas produced from a non-cryogenic source into the well and/or reservoir where the gas and/or oil is located.

Abstract: A process for separating at least one of CF4 and C2F6 from a gas. The process includes the steps of: (a) contacting a gas mixture comprising (i) at least one of CF4 and C2F6, (ii) at least one of NF3, CHF3, and N2, and (iii) SF6 with a membrane at conditions effective to obtain a retentate stream rich in SF6 and at least one of CF4 and C2F6, and a permeate stream rich in at least one of NF3, CHF3, and N2; and (b) contacting the retentate stream with an adsorbent at conditions effective to adsorb SF6 and produce a product stream rich in at least one of CF4 and C2F6.

Abstract: A gas-separation membrane enables the economical separation of noble gases, especially xenon, from oxygen, nitrogen, carbon dioxide or mixtures of the latter gases. The membrane of the present invention includes a thin discriminating layer selected from the group consisting of polycarbonate, polyester, and polyestercarbonate. In the preferred embodiment, the thin discriminating layer includes material selected from the bisphenolic group consisting of 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane, 2,2-bis(3,5-dichloro-4-hydroxyphenyl)propane, and 9,9-bis(3,5-dibromo-4-hydroxyphenyl)fluorene. The invention also includes the method of using the membrane, made as described above, either in a single-stage process or in a multiple-stage process, to provide the desired product gas. Several membrane units, made according to the present invention, may be manifolded together so as to operate in a parallel fashion, to provide an increased volume of product gas at the same desired purity.

Abstract: A method of enriching chlorine gas is described, which method comprises: (a) providing a supported ceramic membrane having a feed side and a permeate side; (b) bringing a feed gas comprising chlorine gas and contaminant gas into contact with the feed side of the ceramic membrane; (c) removing a gaseous permeate depleted in chlorine from the permeate side of the ceramic membrane; and (d) recovering a gas enriched in chlorine from the feed side of the ceramic membrane. The supported ceramic membrane has pore diameters in the range of from 3 angstroms to 12 angstroms. Preferably, the supported ceramic membrane is a substantially cylindrical supported ceramic membrane having a substantially cylindrical internal coaxial passage.

Abstract: A process for reducing pollutants, particularly nitrogen oxides from combustion gases during a combustion process that takes place while oxygen is supplied, includes providing oxygen needed for the combustion process by separating oxygen from a gas mixture containing oxygen and nitrogen in a two-step process including (a) enriching the gas mixture with oxygen in a first step to provide an enriched gas mixture; and (b) separating oxygen out of the enriched gas mixture in a second step, wherein, during at least one step oxygen depleted gas mixture is removed via an outlet provided with permeability means that cause the outlet to have a higher permeability for nitrogen than oxygen.

Abstract: A process for recovering SF.sub.6 from a gas is provided. The process includes the step of contacting a gas stream comprising SF.sub.6 and at least one of N.sub.2, O.sub.2, CO.sub.2, and H.sub.2 O with a membrane in at least one membrane separation unit at conditions effective to obtain a retentate stream rich in SF.sub.6 and a permeate stream rich in at least one of N.sub.2, O.sub.2, CO.sub.2, and H.sub.2 O. A process for forming solidified Mg metal is also provided. The process includes recovering and/or recycling of SF.sub.6 and/or CO.sub.2.

Abstract: The present invention has a resist processing apparatus for supplying a processing solution onto an object to be processed to perform a resist process, including a processing solution supply nozzle for supplying the processing solution onto the object to be processed, a processing solution feeding arrangement for feeding the processing solution to the processing solution supply nozzle, a processing solution flow path arranged to extend between the processing solution feeding arrangement and the processing solution supply nozzle, and a processing solution deaeration mechanism arranged at an intermediate portion of the processing solution flow path to deaerate the processing solution.