Abstract: Valuable process gas is dried to a low water content, for example a dew point of less than -20.degree. F., using membrane separation in which compression of the permeate gases and condensation and separation of liquid water from the permeate stream is combined with a total recycle of uncondensable permeate gases so that no process gas is lost as a result of the drying operation. Feed gas is combined with the recycled gas either prior to compressing, cooling and separating the liquid water from the process gas or subsequent to these steps, depending upon the pressure of the available feed stream to be dried. Membrane separation efficiency is improved by sweeping the downstream surfaces of the membrane with dried product gas. All of the sweep gas is recaptured with the permeate gases and returned to the separation unit, thereby enabling 100%, recovery of the fresh feed gas from the drying operation. Only liquid water and dissolved gases are purged from the system.
Type:
Grant
Filed:
May 6, 1992
Date of Patent:
November 9, 1993
Assignee:
Permea, Inc.
Inventors:
Steven R. Auvil, Jung S. Choe, Lyndon J. Kellogg, Jr.
Abstract: The present invention is a liquid nitrogen reflux means improvement capable of allowing the operation of conventional dual and triple reboiler air separation cycles at elevated pressures.
Abstract: The present invention is directed to adsorptive separation of nitrogen with active adsorbent phases with high N.sub.2 capacity and high heats of adsorption when diluted with inert material at levels ranging from 5% to 80%. The presence of diluent reduces the temperature swings in the adsorbent bed, which increases the utilizable effective N.sub.2 working capacity and decreases the relative amount of O.sub.2 left unrecovered on the active adsorbent phase. The net result is equal or better process performance allowing utilization of a lower amount of active adsorbent phase. Use of a diluent having a higher heat capacity than that of the active adsorbent phase increases these benefits, but dilution effects are beneficial even for diluents with heat capacities equal to or lower than that of the active adsorbent phase.
Type:
Grant
Filed:
September 23, 1992
Date of Patent:
November 2, 1993
Assignee:
Air Products and Chemicals, Inc.
Inventors:
Thomas R. Gaffney, John F. Kirner, Ravi Kumar, Robin J. Maliszewskyj
Abstract: The present invention is directed to a process for adsorptive separation of carbon monoxide or olefins from gas mixtures using adsorbents, which comprise cuprous compounds dispersed on amorphous oxide or carbon macroporous supports. The compositions are prepared by impregnating cupric compounds on, preferably pretreated, supports with the aid of an aqueous solution of an ammonium salt of a di- or polycarboxylic acid dispersant, such as ammonium citrate, followed by reduction of the cupric compound to the corresponding cuprous compound. The reduction can be performed either by the use of elevated temperature or by the use of a reducing gas preferably carbon monoxide at relatively low temperatures up to 150.degree. C. Methods of synthesis are also disclosed.
Type:
Grant
Filed:
September 14, 1992
Date of Patent:
November 2, 1993
Assignee:
Air Products and Chemicals, Inc.
Inventors:
Timothy C. Golden, Wilbur C. Kratz, Frederick C. Wilhelm, Ronald Pierantozzi, Andrzej Rokicki
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 a divalent cation selected from the group consisting of barium, cobalt, copper, chromium, iron, magnesium, manganese, nickel, zinc and mixtures thereof in a ratio of preferably 5% to 50% of the divalent cation and 50% to 95% lithium.
Type:
Grant
Filed:
October 5, 1992
Date of Patent:
November 2, 1993
Assignee:
Air Products and Chemicals, Inc.
Inventors:
Charles G. Coe, John F. Kirner, Ronald Pierantozzi, Thomas R. White
Abstract: A packaged towelette composed of a sheet of nonwoven fibers impregnated with a binder which is a polyvinyl alcohol or an aqueous polymer emulsion containing polyvinyl alcohol as the protective colloid, the sheet being maintained in a wet condition within the package by contact with a nonaqueous lotion composition which is a liquid organic compound that is a nonsolvent for polyvinyl alcohol.
Abstract: The present invention relates to an improvement for the production of argon from cyrogenic air separation processes. In particular, the improvement comprises satisfying a portion of the crude argon column condensing duty with refrigeration provided from the vaporization of a portion of the liquid oxygen from the bottom of the low pressure column.
Abstract: Method and apparatus for generating an oxy-fuel flame with lowered NOX products by confining the oxy-fuel flame produced in a concentric orifice burner along a path defined by the rate of flame propagation and the diameter of the burner.
Type:
Grant
Filed:
March 30, 1992
Date of Patent:
October 26, 1993
Assignees:
Combustion Tec, Inc., Air Products and Chemicals, Inc.
Inventors:
Aleksandar G. Slavejkov, Zbigniew Zurecki, Mahendra L. Joshi, James K. Nabors
Abstract: The invention relates to reaction injection molded elastomers derived from high molecular weight polyether polyols, an aromatic diamine chain extender, a polyisocyanate and a hydroxyl-containing organotin catalyst. The reaction injection molded (RIM) elastomers of this invention are useful, for example, as automobile body parts.
Abstract: The present invention relates to an improvement for the production of argon from cryogenic air separation processes. In particular, the improvement comprises using a first heat pump cycle to transfer refrigeration from the bottom of the low pressure column to the top of the crude argon column and a second heat pump cycle to transfer refrigeration from the bottom of the low pressure column to the top of the low pressure column.
Abstract: Graphite and/or carbon surfaces are coated with a titanium nitride coating by exposing the substrate to electric arc thermal spray process wherein titanium wire as the source of titanium and nitrogen is used as the propelling (atomizing) gas.
Type:
Grant
Filed:
June 14, 1991
Date of Patent:
October 19, 1993
Assignee:
Air Products and Chemicals, Inc.
Inventors:
Zbigniew Zurecki, Edward A. Hayduk, Jr., John G. North, Robert B. Swan, David L. Mitchell, Jr.
Abstract: An improved process for producing high-moisture containing nitrogen-based atmospheres suitable for oxide and decarburize annealing of carbon steels from non-cryogenically generated nitrogen is presented. These nitrogen-based atmospheres are produced by 1) mixing non-cryogenically generated nitrogen containing less than 5.0 vol. % residual oxygen with a specified amount of hydrogen, 2) humidifying the gaseous feed mixture, 3) feeding the gaseous mixture into the heating zone of a furnace through a diffuser, and 4) converting in-situ the residual oxygen present in it to moisture. According to the present invention, the total amount of hydrogen required for producing suitable atmospheres can be minimized by simultaneously humidifying the feed gas and controlling the residual oxygen level in it. The key features of the present invention include a) humidifying the feed gas prior to introducing it into the heating zone of a furnace operated above about 600.degree. C.
Abstract: A process is set forth for the separation of one or more, more permeable components from one or more, less permeable components in a feed stream. The process suggests two membrane separation stages in series wherein the feed is introduced into the high pressure side of the first stage, the non-permeate stream from the first stage is introduced into the high pressure side of the second stage and wherein the permeate stream from the second stage is compressed and recycled to the low pressure side of the first stage.
Abstract: The present invention is an improvement to a process for the cryogenic distillation of air to produce both nitrogen and oxygen products carried out in a single distillation column system wherein a feed air stream is distilled thereby producing a nitrogen overhead and a liquid oxygen bottoms. The improvement is characterized in that: (a) operating the single distillation column at a pressure between 70 and 300 psia [480 and 2,070 kPa.sub.
Abstract: Volatile .beta.-diketonate alkaline earth metal complexes useful in chemical vapor deposition (CVD) operations are formed using a cyclic ligand, such as a macrocyclic crown ether, to increase the degree of coordination and shielding around the individual metal ions in the diketonate structure. The resultant monomeric complexes readily volatize to give a chemically stable vapor.
Abstract: The present invention is a liquid nitrogen reflux means improvement capable of allowing the operation of conventional dual and triple reboiler air separation cycles at elevated pressures.
Abstract: A method for preparing a polymer powder which is redispersible in water by atomizing an aqueous non-polyvinyl alcohol stabilized polymer dispersion containing a dispersing aid consisting of vinyl pyrrolidone homopolymer.
Abstract: An aqueous contact adhesive composition comprising an aqueous adhesive copolymer emulsion, the adhesive composition having a durometer hardness measured on the type A scale by ASTM D2240 of at least 20, and a blowing agent. The aqueous contact adhesive composition is applied as a coating to a surface of each of two substrates, then foamed, and substantially dried to provide a dry cellular adhesive coating. The adhesive-coated surfaces are then joined. The preferred contact adhesive composition comprises a vinyl acetate/ethylene/N-methylolacrylamide copolymer emulsion.
Abstract: A packaged towelette comprising a sheet of nonwoven fibers impregnated with a polyvinyl alcohol containing binder and in contact with an aqueous solution containing borate ions and bicarbonate ions.
Abstract: This invention relates to improved wet oxidation process for the destruction of organic components in a wastewater stream contaminated with inorganic salts. In wet oxidation, the wastewater stream is contacted with an oxygen-containing water stream at elevated temperatures and pressures. The improvement for treating aqueous wastewater streams contaminated with inorganic salts wherein the organic contaminants are present in an amount from about 0.5 to 2% by weight resides in oxidizing the organic components in a tubular reactor at a temperature ranging from 325.degree. C. to not more than 370.degree. C. and a pressure ranging from 220 to 345 bar. The oxidation reaction is carried out in a reaction time of 5 minutes or less.
Type:
Grant
Filed:
July 28, 1992
Date of Patent:
October 5, 1993
Assignee:
Air Products and Chemicals, Inc.
Inventors:
John E. Sawicki, Baldomero Casas, Chiung-Yuan Huang, William R. Killilea, Glenn T. Hong