Abstract: The present invention is directed to a process for separating nitrogen from gas mixtures containing nitrogen and less strongly adsorbed components such as oxygen, hydrogen, argon or helium by use of an at least binary exchanged X-zeolite having lithium and calcium and/or strontium ions in ratio of preferably 5% to 50% calcium and/or strontium and 50% to 95% lithium.
Type:
Grant
Filed:
December 20, 1991
Date of Patent:
October 6, 1992
Assignee:
Air Products and Chemicals, Inc.
Inventors:
Charles G. Coe, John F. Kirner, Ronald Pierantozzi, Thomas R. White
Abstract: Useful as catalysts for the reaction of a polyisocyanate or a partially blocked polyisocyanate with a hydroxy-containing compound are organotins of the formula ##STR1## where R is a C.sub.1 -C.sub.8 alkyl or an aryl group,Y is --CH.sub.2 CH.sub.2 --, --CH.sub.2 CH.sub.2 CH.sub.2 --, --CH.sub.2 CH(CH.sub.3)--, --CH.sub.2 CH(OH)CH.sub.2 --, or ##STR2## and X is a linking group which may be --S-- or --O--.Also disclosed are cationic electrodepositable compositions containing such catalysts.
Abstract: This invention relates to an improved process for preparing dihydroperoxyalkanes and, particularly, dimethyldihydroperoxyhexane. The improvement resides in utilizing a tetrahydrofuran derivative which is a liquid as a feedstock. This feedstock then is reacted with hydrogen peroxide in the presence of sulfuric acid to form the dihydroperoxide.
Abstract: The invention describes a catalytic process for destroying NOx from oxygen-containing combustion products wherein methane serves as a reductant. The process comprises contacting the NOx-containing combustion products with a desired amount of methane and oxygen in the presence of a metal-exchanged crystalline zeolite having a silicon to aluminum ratio of greater than or equal to about 2.5 under conditions sufficient to effect conversion to gaseous nitrogen, water and carbon oxides. The zeolites are exchanged with a cation selection from the group consisting of cobalt, nickel, iron, chromium, rhodium and manganese.
Abstract: The present invention relates to a composition for depositing a temporary, selectively soluble protective coating onto a substrate and a process for using the same. The composition consists essentially of a copolymer consisting of 35 to 85 weight percent vinyl acetate and from 15 to 65 weight percent of a predefined monoalkyl maleate which is dispersed in a solvent/vehicle. The protective coatings deposited therefrom are substantially impervious to aqueous media having acidic or neutral pH and provide an effective barrier against damage to the substrate's surface. At the desired time, the protective coating can be removed from the substrate by dissolution in an aqueous alkaline solution.
Abstract: Useful as catalysts for the reaction of a polyisocyanate or a partially blocked polyisocyanate with a hydroxy-containing compound are organotin compositions obtained by reacting a diorganotin oxide of the formula R.sub.2 SnO of a diorganotin dichloride of the formula R.sub.2 SnCl.sub.2 with a compound of the formula HS--CH.sub.2 CH(OH)CH.sub.2 XH where R is a C.sub.1 -C.sub.8 alkyl or an aryl group and X is --O-- or --S--.Also disclosed are cationic electrodepositable (CED) compositions containing such catalysts.
Abstract: A novel composition of matter is disclosed comprising perfluorinated, ethyldimethyl cyclohexane. The compound has unique utilities in vapor phase heating and soldering, oxygen transport for biological fluids and other requirements for an inert, stable fluid.
Abstract: Volatile liquid organometallic copper complexes are provided which are capable of selectively depositing a copper film onto metallic or other electrically conducting portions of a substrate surface under CVD conditions. There organometallic copper complexes are represented by the structural formula: ##STR1## wherein R.sup.1 and R.sup.3 are each independently C.sub.1 -C.sub.8 perfluoroalkyl, R.sup.2 is H, F or C.sub.1 -C.sub.8 perfluoroalkyl, R.sup.4 is H, C .sub.1 -C.sub.8 alkyl, or Si(R.sup.6).sub.3, each R.sup.5 is independently H or C.sub.1 -C.sub.8 alkyl and each R .sup.6 is independently phenyl or C.sub.1 -C.sub.8 alkyl. A process for depositing copper films using these organometalic copper complexes is also provided.
Abstract: A method for preparing a polyurethane foam which comprises reacting an organic polyisocyanate and a polyol in the presence of a blowing agent, a cell stabilizer and a catalyst composition consisting essentially of at least one compound of the following formula: ##STR1## where R is hydrogen, C.sub.1 -C.sub.8 alkyl, C.sub.6 -C.sub.10 aryl or C.sub.7 -C.sub.10 aralkyl, and n is 0-3. The preferred catalyst consists essentially of of the compound when n is 0, namely 3-quinuclidinol.
Abstract: In a vinyl acetate-ethylene copolymer emulsion prepared by the aqueous emulsion copolymerization of vinyl acetate and ethylene in the presence of a polyvinyl alcohol stabilizing system, the improvement which comprises a vinyl acetate-ethylene copolymer emulsion prepared in the presence of a stabilizing system consisting essentially of:(a) 0.2 top 1.5 wt % low molecular weight, partially hydrolyzed polyvinyl alcohol,(b) 0.5 to 2.5 wt % medium molecular weight, partially hydrolyzed polyvinyl alcohol, and(c) 1 to 4 wt % medium molecular weight and/or high molecular weight, fully hydrolyzed polyvinyl alcohol,the weight percentages based on vinyl acetate monomer.
Abstract: Carboxamides having the structural formula:R.sup.1 CHR.sup.2 CH(OR.sup.3)NHCR.sup.4 Owherein:R.sup.1 is H, C.sub.1 -C.sub.6 alkyl or aryl;R.sup.2 is H, C.sub.1 -C.sub.6 alkyl;R.sup.3 is benzyl, C.sub.1 -C.sub.8 alkyl or hydroxyalkyl; andR.sup.4 is H, C.sub.1 -C.sub.6 alkyl or aryl;are synthesized by reacting an aldehyde having the structural formula: R.sup.1 CHR.sup.2 CHO wherein R.sup.1 and R.sup.2 are as defined above, with an alcohol having the structural formula: R.sup.3 OH, wherein R.sup.3 is as defined above, and an amide having the structural formula: R.sup.4 CONH.sub.2 wherein R.sup.4 is as defined above, in the presence of a strong acid catalyst at a temperature in the range of 0.degree.-200.degree. C.
Type:
Grant
Filed:
February 24, 1988
Date of Patent:
September 1, 1992
Assignee:
Air Products and Chemicals, Inc.
Inventors:
Mark L. Listemann, Ronald Pierantozzi, John N. Armor
Abstract: A process is provided for selectively separating oxygen from an oxygen-containing fluid stream by bringing said fluid stream into contact with a high capacity solid state cyanocobaltate complex in a non-aluminosilicate environment represented by the chemical formula:A.sub.x/z.sup.z+ [Co(CN).sub.n ].sup.x- .multidot.pSwhere:A is an alkali, alkaline earth, transition, or Group 12 metal atom;z is 1, 2 or 3;n is any number from 3 to 5;x is n-2;p is any number from greater than zero to 6; andS is a ligand which is capable of coordinating with A.sup.z+, Co or both.These complexes chemically bind oxygen to form novel oxygen adducts, thereby selectively removing oxygen from the fluid stream. The bound oxygen may be recovered by increasing the temperature or by reducing the partial pressure of O.sub.2 above the adduct.
Type:
Grant
Filed:
March 15, 1991
Date of Patent:
August 25, 1992
Assignee:
Air Products and Chemicals, Inc.
Inventors:
Dorai Ramprasad, Guido P. Pez, Ronald M. Pearlstein, Ingrid K. Meier
Abstract: The present invention relates to a process for the liquefaction of a nitrogen stream produced by separating air components, by using the combination of cryogenic distillation with improved refrigeration. Very cold liquefied natural gas (LNG) is employed as refrigerant, with the LNG currently being revaporized for transportation.Multi-stage component compression is used, with the component feed to each compression stage being precooled using sequential refrigeration from the LNG. Expander means for the coldest air component product stream provides supplemental refrigeration at the cold end beyond that which is available from the refrigerant LNG.
Abstract: A method for controlling the operation of a liquefied natural gas (LNG) process which utilizes gas turbine-driven refrigeration compressors is disclosed. A feedforward control system compensates for the effects of changes in ambient air temperature on the plant operating efficiency by periodically predicting a new temperature and resetting the set points of key feedback controllers in anticipation of this new temperature, thereby optimizing the operation of the plant and minimizing the specific fuel consumption at a given LNG production rate.
Type:
Grant
Filed:
July 31, 1991
Date of Patent:
August 18, 1992
Assignee:
Air Products and Chemicals, Inc.
Inventors:
Yu-Nan Liu, Glenn E. Kinard, David A. Zagnoli
Abstract: The present invention relates to a process for liquefaction of a nitrogen stream produced by a cryogenic air separation unit. Cold liquid natural gas (LNG) is employed as refrigerant.A critical feature step of the invention is that the temperature of the vaporizing LNG should be maintained at a temperature lower than the critical temperature of the nitrogen stream being liquefied.The process involves compressing the nitrogen stream to at least 350 psi in a multistage compressor wherein interstage cooling is provided by heat exchange against vaporizing LNG. Further cooling and flashing of a portion of the liquid nitrogen stream serves to produce a quantity of liquid nitrogen that is free of hydrocarbon contamination and suitable for recycle to the air separation unit.
Abstract: This invention relates to a cryogenic process for the separation of air utilizing an integrated multi-column distillation system wherein an ultra high purity nitrogen rich, oxygen rich and optionally an argon rich product are generated. In the cryogenic distillation separation of air, air is initially compressed, pretreated and cooled for separation into its components. Ultra high purity, e.g., nitrogen having less than 0.1 ppm of volatile impurities is generated with enhanced nitrogen product recovery by withdrawing liquid nitrogen from the higher pressure column at an intermediate point and charging that fraction as reflux to the lower pressure column, withdrawing a nitrogen stream which is rich in volatile contaminants from the top of the high pressure column, partially condensing the nitrogen stream and removing the uncondensed portion as a purge stream, and, withdrawing an ultra high purity nitrogen product at a point below a nitrogen vapor withdrawal point at the top of the lower pressure column.
Abstract: The present invention relates to a process for the liquefaction of a nitrogen stream produced by separating air components using the combination of cryogenic distillation with improved refrigeration. Very cold liquid natural gas (LNG) is employed as refrigerant, with the LNG concurrently being revaporized for transportation. The requisite circulating liquid is produced by compressing the nitrogen feed streams in a multi-stage compressor, wherein the interstage cooling is provided by heat exchange against the part of the recirculating nitrogen stream yielding a high pressure nitrogen stream. The resulting nitrogen, having a pressure greater than that of the LNG refrigerant, is then used as the circulating fluid to transfer refrigeration from the LNG to other low pressure nitrogen feed streams prior to their cold compression. Also, high pressure nitrogen is used as circulating fluid to transfer refrigeration to precool feed air to cryogenic temperatures prior to its compression in an air separation unit.
Abstract: A method for extruding polyvinyl alcohol which comprisesadding sufficient energy to the polyvinyl alcohol to both melt it and essentially eliminate the crystallinity in the melt, andsimultaneously removing energy from the melt at a rate sufficient to avoid decomposition of the polyvinyl alcohol.Rapidly cooling the extruded melt reduces the heat history and improves the resulting color of the extrudable polyvinyl alcohol.
Type:
Grant
Filed:
September 1, 1989
Date of Patent:
August 11, 1992
Assignee:
Air Products and Chemicals, Inc.
Inventors:
F. Lennart Marten, Amir Famili, James F. Nangeroni
Abstract: The present invention relates to improvements to a process and apparatus for the cryogenic distillation of mixtures, which comprise oxygen, nitrogen and argon, e.g. air. The improvement comprises effectuating intimate contact of the liquid and vapor phase streams utilizing a structured packing to effectuate the intimate contact in at least .[.those.]. .Iadd.one of the .Iaddend.regions of the distillation column system where argon concentration is within the range from about 0.6 to about 75 volume percent.[.,.]. and .[.operating the process such that.]. the densimetric superficial gas velocity .[.in those regions.]. is at least 0.06 feet per second. .[.
Type:
Grant
Filed:
May 31, 1991
Date of Patent:
August 25, 1992
Assignee:
Air Products and Chemicals, Inc.
Inventors:
Douglas L. Bennett, Keith A. Ludwig, George S. Witmer, Charles M. Woods