Abstract: A staged adsorbent membrane system is operated to separate a gas mixture wherein more strongly adsorbed secondary components preferentially adsorb and permeate through the adsorbent membrane in the first stage. Less strongly adsorbed primary components are recovered therefrom in a nonpermeate gas product stream. Preferably two stages are utilized wherein the permeate gas from the first stage is introduced into the second stage and the nonpermeate gas from the second stage is recycled to the first stage as additional feed gas to increase the overall recovery and/or purity of the nonpermeate gas product. The two-stage membrane system is operated such that the ratio of the recovery of the primary component in the first stage to the recovery of the primary component in the second stage is less than about 1.0. The method is particularly useful for the recovery of hydrogen from hydrogen-containing gas mixtures.

Abstract: Oxygen is recovered from a hot, compressed oxygen-containing gas, preferably air, by an oxygen-selective ion transport membrane system. Hot, pressurized non-permeate gas from the membrane is cooled and useful work is recovered therefrom by expansion at temperatures below the operating temperature of the membrane. The recovered work is used together with the oxygen permeate product in applications such as oxygen-enriched combustion of liquid fuels, wood pulping processes, steel production from scrap in mini-mills, and metal fabrication operations. Oxygen permeate product can be compressed utilizing a gas booster compressor driven by expansion of cooled, pressurized non-permeate gas.

Abstract: A method is disclosed for producing large single crystals. According to the initial steps of this method, a plurality of single crystal wafers are crystallographically oriented to form a seed plate which is patterned. The patterned seed plate is selectively etched to expose the bare surface of the seed plate. The exposed, patterned bare surface of the seed plate is etched to form a plurality of nucleation structures. Each of the nucleation structures protrude outwardly from the underlying surface of the seed plate and provide ideal structures for the growth of large, single crystals. The resulting large, single crystals can be separated from the seed crystals by etching, physical or chemical means.

Abstract: A method for increasing product recovery or reducing the size of steam methane reformer and pressure swing adsorption systems utilized for hydrogen production. A significant portion of the hydrogen in the PSA depressurization and purge effluent gas, which is otherwise burned as fuel in the reformer, is recovered and recycled to the PSA system to provide additional high purity hydrogen product. This is accomplished by processing selected portions of the depressurization and purge effluent gas in adsorbent membrane separators to increase hydrogen content for recycle to the PSA system. Remaining portions of the depressurization and purge effluent gas which contain lower concentrations of hydrogen are utilized for fuel value in the reformer.

Abstract: This invention relates to an improved process for producing a vinyl alcohol containing polymer having a narrow particle size without substantial reactor fouling. The process for producing the vinyl alcohol containing polymer involves hydrolyzing a vinyl ester containing polymer, e.g., a polymer containing polymerized vinyl alkanoate units in the presence of an alcoholic medium and a hydrolysis catalyst in the presence of an alcoholic medium having finely divided, inert material such as an alkali metal carbonate dispersed therein. The finely divided inert material acts as nucleating sites for the polyvinyl alcohol as it precipitates from the solution during hydrolysis.

Abstract: Mortar formulations comprising a hydraulic cement and a PVOH stabilized acrylic latex or a spray dried redispersible powder made from the PVOH stabilized acrylic latex are disclosed. These include formulations suitable for use as tile mortars, patching mortars, EIFS base coats and grouts. An acrylic latex that, when formulated with hydraulic cement, has performance advantages over other latex resins in mortar, patch and exterior insulation and finishing systems. The spray dried, redispersible acrylic emulsion polymer that, when formulated with hydraulic cement, has comparable or better performance than a liquid latex in mortars and patches.

Abstract: An electrochemical device is disclosed comprising a plurality of planar electrolytic cells connected in series, each cell having an oxygen ion-conducting electrolyte layer, an anode layer and a cathode layer associated with the electrolyte layer, electrically conductive interconnect layers having gas passages situated therein for transporting gaseous streams, which interconnect layers electrically connect the anode layer of each electrolytic cell to the cathode layer of an adjacent planar cell, and sealing means positioned between the interconnect layers and the electrolytic cells to provide a gas-tight seal therebetween. The configuration of the interconnect layer and the placement of the seal means provides a separation between the seal and the conductive pathway of electrons between the anode layer and cathode layer which prevents corrosion or deterioration of the seal.

Abstract: The present invention is a process for very low temperature chemical vapor deposition of silicon dioxide, comprising the steps ofa) heating a substrate upon which silicon dioxide is to be deposited to a temperature in the range of approximately 150 to 500.degree. C. in a vacuum maintained at a pressure in the range of approximately 50 to 750 mTorr;b) introducing into said vacuum an organosilane containing feed and an oxygen containing feed, said organosilane containing feed consisting essentially of one or more compounds having the general formula: ##STR1## wherein R.sup.1 and R.sup.2 are independently alkyl, alkenyl, alkynyl, or aryl, having C.sub.1 to C.sub.6, or R.sup.1 and R.sup.2 are combined to form an alkyl chain C.sub.x (R.sup.3).sub.2, where R.sup.3 is independently H, C.sub.x H.sub.2x+1, and x=1-6, and R.sup.4 is independently H, C.sub.y H.sub.2y+1 where y=1-6; andc) maintaining said temperature and vacuum thereby causing a thin film of silicon dioxide to deposit on the substrate.

Abstract: This invention relates to a process for producing ethylidene diacetate by the reaction of dimethyl ether, acetic acid, hydrogen and carbon monoxide at elevated temperatures and pressures in the presence of an alkyl halide and a heterogeneous, bifunctional catalyst that is stable to hydrogenation and comprises an insoluble polymer having pendant quaternized heteroatoms, some of which heteroatoms are ionically bonded to anionic Group VIII metal complexes, the remainder of the heteroatoms being bonded to iodide. In contrast to prior art processes, no accelerator (promoter) is necessary to achieve the catalytic reaction and the products are easily separated from the catalyst by filtration. The catalyst can be recycled for 3 consecutive runs without loss in activity.

Abstract: Vinyl naphthenate monomer mixtures are prepared by transvinylation of naphthenic acid in the presence of a catalyst of a palladium carboxylate complexed with one or more aryl N-containing ligands and distilling the resulting vinyl naphthenate monomers in the presence of the catalyst at pot temperatures exceeding 80.degree. C. The catalyst is stable and can be re-used over several transvinylation reaction runs.

Abstract: An integrated gas turbine/air separation system is operated at or below full system load by feeding the air separation unit with air from a dedicated air feed compressor and optionally with extracted air from the gas turbine air compressor. When the gas turbine air compressor discharge drops below a selected pressure at part load conditions, the flow of extracted air to the air separation unit is discontinued and the air separation unit operates at constant pressure supplied only by the air feed compressor. This mode of operation is particularly useful in an integrated gasification combined cycle (IGCC) power generation system and allows the design of the oxygen and nitrogen product compressors such that the compressors operate at high efficiency during full load IGCC operation.

Abstract: This invention is an emulsion composition comprised of acrylic ester monomers polymerized in the presence of fully hydrolyzed poly(vinyl alcohol) or a partially hydrolyzed poly(vinyl alcohol) provided the molecular weight of the low molecular weight poly(vinyl alcohol) is from 5,000 to 13,000 as the only stabilizer and a chain transfer agent. The improvement over the known prior art is the ability to incorporate fully hydrolyzed poly(vinyl alcohol) without the need for other surfactants or special processing.

Abstract: Hydrocarbons are recovered from the product purge gas in an alkene polymerization process by absorption of heavier hydrocarbons from the purge gas by an intermediate hydrocarbon stream to yield a vapor rich in inert gas and alkene monomer. Alkene monomer is condensed and rectified by dephlegmation at low temperatures from the inert gas, flashed and vaporized to provide refrigeration for the condensation step, and recycled to the polymerization process. The intermediate hydrocarbon from the absorption step is recycled to the polymerization process. Optionally a portion of the inert gas is reused for purge gas.

Abstract: A process for preparing triethylenediamine by passing an ethanolamine, ethyleneamine, piperazine or morpholine over a pentasil-type zeolite at elevated temperature characterized by employing a ZSM-5 zeolite in the hydrogen or ammonium form which has been pretreated with an aqueous solution of a chelating agent capable of forming a chelate-aluminum complex.

Abstract: A process for pressure swing adsorption of oxygen from a gas mixture containing at least oxygen and nitrogen to recover an unadsorbed nitrogen enriched product from a plurality of parallel piped adsorbent beds undergoing adsorption, depressurization and repressurization wherein the improvement is conducting a pressure transfer from one bed to another from an intermediate point of the bed finishing adsorption to a point closer to the feed end of a bed that is repressurizing to improve productivity and recovery of nitrogen enriched gas in the process.

Abstract: Method and apparatus for removing trace levels of impurities from gases stored cryogenically in a storage vessel in liquid form by passing a vaporized portion of liquified gas from the storage vessel through a bed of adsorbent while using the liquified gas to cool the adsorbent. Vaporized gas resulting from cooling of the adsorbent with the stored liquified gas can be combined with the vapor withdrawn from the storage vessel prior to being passed through the bed of adsorbent. Liquified gas can be withdrawn from the storage vessel, vaporized and the vaporized gas combined with the vaporized gas from the storage vessel prior to being passed through the bed of adsorbent.

Abstract: Use of a shrouding gas to combine with and protect a turbulent gas jet issuing from an orifice enables control of a gas jet stream composition downstream from the orifice. The natural aspiration rate of the gas jet is used to determine the flowrate of shrouding gas which is introduced around the gas jet in a soft gas cushion which does not disrupt the flow pattern of the gas jet but instead is entrained into the jet stream to the exclusion of ambient gases in the atmosphere. Preferably shrouding gas is replaced at least at the rate at which it is entrained. Apparatus for this process uses a porous shroud, preferably of metal foam, through which shrouding gas flows evenly around the gas jet as it issues from a nozzle orifice. Provision for tangential entry of shrouding gas into a manifold which feeds the porous shroud prevents the shrouding gas from impinging upon the porous shroud and causing uneven flow around the gas jet.

Abstract: Reductive alkylation of branched, short chain diamines, such as 2-methyl-1,5-pentanediamine, with certain aldehydes or ketones of moderate molecular weight, such as benzaldehyde or methyl isobutyl ketone, produces novel tri- and difunctional amines which are useful in curing epoxy resins to compositions having improved flexibility and enhanced resistance to moisture and chemicals. Particularly favorable results are achieved when this curative is combined in the epoxy formulation with low molecular weight acrylic copolymers added as flexibilizers. Further improvements are available by including in the recipe monofunctional epoxy or acrylic reactive diluents.

Abstract: Heterogeneous polymer mixtures comprising a polymer in liquid or supercritical CO.sub.2 are stabilized by employing a poly(propylene oxide) or poly(butylene oxide) based surfactant. These surfactants are especially well suited for stabilizing heterogeneous polymer mixtures formed by micronizing techniques as well as by precipitation of a compressed fluid antisolvent applications.

Abstract: A method for the separation and recovery of fluorochemicals from a gas stream containing a diluent gas and fluorochemicals by contact of the gas stream with a membrane, comprising the steps of: compressing a gas stream containing a diluent gas and fluorochemicals to an elevated pressure; heating the gas stream containing a diluent gas and fluorochemicals to an elevated temperature sufficient to increase the flux of the permeate stream and to increase the selectivity of the membrane for the permeation of the diluent gas relative to the permeation of the fluorochemicals; contacting the gas stream with a membrane which is selectively more permeable to the diluent gas than the fluorochemicals to result in a permeate stream rich in the diluent gas and a retentate rich in fluorochemicals; contacting the gas stream with one or more additional membranes which are selectively more permeable to the diluent gas than the fluorochemicals to result in a second permeate stream rich in the diluent gas and a second retentate