Abstract: A method is described for recovering nitrogen from air in a three bed vacuum swing adsorption technique in which the beds are not rinsed with nitrogen gas before recovering a nitrogen recycle stream and a nitrogen product.

Abstract: A vinyl acetate-ethylene copolymer emulsion comprising an aqueous colloidal dispersion of a copolymer containing 65 to 90 wt % vinyl acetate and 10 to 35 wt % ethylene prepared by the emulsion polymerization of the monomers in the presence of a stabilizing system consisting essentially of an 86 to 90 mole % partially hydrolyzed polyvinyl alcohol, a 98 to 99+ mole % fully hydrolyzed polyvinyl alcohol, in a partially hydrolyzed polyvinyl alcohol:fully hydrolyzed polyvinyl alcohol weight ratio from 3:1 to 1:3, and a nonionic polyalkoxylated surfactant.Also disclosed is a carpet backing adhesive composition comprising such a vinyl acetate-ethylene copolymer emulsion, about 0.1 to 3 parts by weight dispersant, about 0.1 to 10 parts by weight thickening agent and between 300 and about 1000 parts by weight filler, all of the components being per 100 parts of the copolymer.

Abstract: An integrated cryogenic air separation unit power cycle system is disclosed wherein the air separation unit (ASU) is operated at elevated pressure to produce moderate pressure nitrogen. The integrated cycle combines a gasification section wherein a carbon source, e.g., coal is converted to fuel and combusted in a combustion zone. The combustion gases are supplemental with nitrogen from the air separation unit and expanded in a turbine. Air to the cryogenic air separation unit is supplied via a compressor independent of the compressor used to supply air to the combustion zone used for combusting the fuel gas generated in the gasifier system.

Abstract: This invention relates to a process for the separation of acrylonitrile used in the cyanoethylation of glycols to produce a bis(cyanoethylated) aliphatic glycol from the resulting glycol which is then reduced with hydrogen to produce the corresponding bis(aminopropoxy) alkane. In this process, acrylonitrile or methacrylonitrile is reacted with an aliphatic glycol in stoichiometric excess and the acrylonitrile removed from the cyanoethylated glycol by reaction with aliphatic primary or secondary alcohol prior to effecting the hydrogenation of the cyanoethylated aliphatic glycol in the presence of the acrylonitrile-amine reaction product. The reaction product then can be separated by conventional techniques such as distillation.

Abstract: A method of incorporating fluorine into the YBa.sub.2 Cu.sub.3 O.sub.7-x system by annealing YBa.sub.2 Cu.sub.3 O.sub.7-x powder in a fluorine-containing gas, especially NF.sub.2 gas. The YBa.sub.2 Cu.sub.3 O.sub.7-x material is annealed in the fluorine-containing gas (either pure NF.sub.3 or NF.sub.3 /O.sub.2 blend of F.sub.2 /N.sub.2 blend) at a temperature which allows sufficient reactivity with the fluorine gas while maintaining the system well below temperatures at which oxygen incorporation is observed to take place in the normal YBa.sub.2 Cu.sub.3 O.sub.7-x system.

Abstract: Corrosion resistance of valves or fittings exposed to corrosive attack by the environment in which they are normally used can be improved by covering those portions of the valve or fitting of thinner cross-section by a thin metal sleeve fabricated from an alloy resistant to corrosive attack by the environment.

Abstract: This invention relates to a cryogenic process for the separation of air utilizing an integrated multi-column distillation system wherein a nitrogen rich, oxygen rich and argon rich product are generated. In the cryogenic distillation separation of air, air is initially compressed, pretreated and cooled for separation into its components. Moderate pressure, e.g., 25-80 psia nitrogen is generated with enhanced nitrogen product purity and greater recovery of both nitrogen and argon by effecting a high boil-up rate in the bottom of the lower pressure column, thereby creating a reduced liquid flow/vapor flow ratio (L/V) and utilizing a higher than customary nitrogen reflux to the top of the lower pressure column, where the concentration of oxygen in nitrogen is less than about 10 ppm by volume or the nitrogen purity is at least about 99.5% by volume. Refrigeration to drive the system is obtained by recovering the energy from the waste nitrogen stream and oxygen vapor from the lower pressure column.

Abstract: This invention relates to an improved process for the cryogenic separation of air and particularly with respect the separation of air in oxygen enriched zones within a distillation column. The improvement resides in utilizing aluminum packing in structured or random form in the oxygen enriched zones wherein the oxygen concentration ranges from about 80 to 96% by volume and optionally a sheet copper packing of structured or random form in the oxygen enriched zones, wherein the oxygen concentration is greater than 97% by volume. The aluminum packing may also be used in an argon column where argon is separated from oxygen by distillation.

Abstract: A method for making a lightweight structure having a high stiffness to weight ratio comprising providing a substrate defining at least a pair of outer surfaces spaced from each other, boring at least one hole through the structure to provide at least one void passage extending through the substrate between the outer surfaces, coating the outer surfaces of the substrate and the surfaces of the passage with a chemical vapor deposited material to a thickness of about one millimeter, plugging the void passage with a plug of a substrate material, and further coating the coated outer surfaces of the substrate and the ends of the plugs with a chemical vapor deposited material to form a continuous monolithic structure thereon.

Abstract: A process for the recovery of methoxyisopropylamine from the reaction of methoxyisopropanol and ammonia under amination conditions. Water is produced as a byproduct and in the distillation separation an azeotrope is formed which includes about 14% water and 86% methoxyisopropylamine. The improvement for enhancing separation of the azeotrope includes initially distilling the mixture of methoxyisopropylamine, methoxyisopropanol and water under sufficient elevated pressure wherein an azeotrope of water and methoxyisopropylamine overhead and an essentially water free bottoms of methoxyisopropylamine and methoxyisopropanol are formed. The overhead from this initial distillation column is charged to a second distillation column operated at reduced pressure wherein an organic free bottoms containing primarily water is obtained.

Abstract: This invention relates to a process for the separation of acrylonitrile used in the cyanoethylation of glycols to produce a bis(cyanoethylated) aliphatic glycol from the resulting glycol which is then reduced with hydrogen to produce the corresponding bis(aminopropyl) aliphatic glycol. In this process, acrylonitrile is reacted with an aliphatic glycol in stoichiometric excess and the acrylonitrile removed from the cyanoethylated glycol by reaction with aliphatic primary or secondary amine prior to effecting the hydrogenation of the cyanoethylated aliphatic glycol in the presence of the acrylonitrile-amine reaction product. The reaction product then can be separated by conventional techniques such as distillation.

Abstract: The present invention is an integrated process for the adsorptive recovery of a high purity carbon monoxide product from a gas mixture containing hydrogen, carbon monoxide, carbon dioxide, methane, and nitrogen, with the potential additional recovery of a hydrogen-rich stream and the recycle of the resulting gas mixture to a reformation reaction to produce the gas mixture with a more favorable carbon monoxide and hydrogen product slate. Separate carbon dioxide recovery can be performed. Hydrogen recovery can be either by adsorptive or by membrane technology. The process achieves high recoveries at reduced capital cost and at reduced product cost.

Abstract: The present invention provides a surface modified polymeric gas separation membrane having improved selectivity, particularly for oxygen/nitrogen gas mixtures, prepared by forming a membrane of a polymer having the structural formula ##STR1## wherein R and R" can be the same or different linear, branched or cyclic alkyl group having one to twelve carbon atoms, or R can be H, with the proviso that both R and R" cannot be methyl, and n is at least 100, and treating the surface of the membrane with a fluoro-oxidizing agent at conditions sufficient to fluoro-oxidize the membrane surface.

Abstract: A process and equipment for making seamless composite tubes. Composite material is applied on a mandrel which includes an inflatable bladder and inserted in a single piece mold. The bladder is pressurized for pressing the composite material against the mold wall for molding and curing thereof. In order to prevent seizing of the tube by the mold and thus allow easy removal of the cured tube, the mold is composed of a composite of resin impregnated carbon fiber material wherein the carbon fiber material has a negative coefficient of thermal expansion along the length thereof and is oriented at an angle of between about 15 and 40 degrees relative to a radial plane of the mold. In order to eliminate the use of inefficient and inconvenient cure ovens, a heat generating element is disposed internally of the mandrel for curing of the composite material.

Abstract: A rapid adiabatic pressure swing adsorption process with a total cycle time ranging from 6 to 60 seconds with feed being introduced into a single separation vessel having dual adsorption layers operated alternately by a pressurized continuous feed gas involving a continuous feed and two continuous product streams, one being enriched in the less strongly adsorbed component of the feed mixture.

Abstract: This invention relates to a process for producing bis-[aminophenyl ketones] and the resulting compositions which are suitable for the preparation of engineering polymers, e.g., polyimides, polyurethanes and a host of other resinous materials. The bis-[aminophenyl ketones] are formed by reacting 2 moles of a nitrophenyl acid halide with an aromatic bridging composition having at least two hydrogen atoms of sufficient reactivity to undergo acylation reactions whereby nitrophenyl ketone groups are attached to the aromatic bridging group. The resulting bis-[nitrophenyl ketones] then are converted to the amine by hydrogenation or by double nucleophilic displacement with an aminophenol.The invention also relates to polyimides and polyamides prepared from such bis-[aminophenyl ketones].

Abstract: The invention relates to an improved process for producing alkenylated aromatic amines which involves the catalytic reaction of an aromatic amine with a diene. The improvement resides in using a solvent in which the aromatic amine and diene are soluble in the proportions present in the reaction but inert to the reaction.

Abstract: The invention pertains to tertiary amines used as catalysts for the preparation of polyurethane foams prepared via the catalytic reaction of a polyisocyanate with a polyol in the presence of blowing agents, etc. The tertiary amine catalysts are prepared by reacting an olefinic nitrile with aliphatic polyol having at least secondary hydroxyl functionality in a ratio less than stoichiometric for providing cyanoalkylated polyol having residual hydroxyl functionality. The resulting cyanoalkylated polyol then is reacted with a secondary amine under conditions for effective reductive alkylation.The tertiary amine catalysts, because of residual secondary hydroxyl functionality, provide for uniform dispersion within a polyurethane formulation; they provide for additional or extended pot life in polyurethane formulations at temperatures below reaction condition, and they are bound by reaction on cure.

Abstract: A process is provided for making a modified carbon molecular sieve which is suitable for separating gases having different adsorption rates on the sieve. The process involves modifying a starting sieve support having a majority of micropores with an effective pore size of about 4.5 to 20 angstroms, with a two-step process in which the sieve is contacted with two different concentrations of a volatile carbon-containing organic compound, preferably a hydrocarbon. The concentration of the carbon-containing compound used in the first step is larger than that in the second step, so that the pore openings of the micropores of the support are narrowed successively in two distinct steps without filling the micropores themselves. The invention also discloses an improved carbon molecular sieve and the separation of gases, such as oxygen from nitrogen, by the use of this improved adsorbent.

Abstract: A method is disclosed for the kinetic separation of gas mixtures using gas-solid chromatography. More specifically, a method is disclosed for the kinetically driven gas-solid chromatographic separation of NF.sub.3 from CF.sub.4 in significant volumes over a specific class of adsorbents to recover NF.sub.3 at high purities, such as 99.99% NF.sub.3.