Patents Examined by Gregory A. Heller
  • Patent number: 5196176
    Abstract: The invention provides a process for the removal of sulfur dioxide from waste gas, comprising the steps of:a) contacting the waste gas with a basic aqueous solution wherein sulfur dioxide is dissolved as sulfite;b) subjecting the aqueous solution containing sulfite to sulfur reducing bacteria in an anaerobic reactor wherein sulfite is reduced to sulfide;c) subjecting the aqueous solution containing sulfide to sulfur oxidizing bacteria in the presence of a limiting amount of oxygen in a reactor wherein sulfide is oxidized to elemental sulfur;d) separating the elemental sulfur form the aqueous solution; ande) recycling the aqueous solution to step a).
    Type: Grant
    Filed: April 12, 1991
    Date of Patent: March 23, 1993
    Assignee: Paques, B.V.
    Inventor: Cees J. N. Buisman
  • Patent number: 5196175
    Abstract: A method of making a three-way catalyst based on platinum group metals, comprising: (a) impregnating an alumina substrate with a platinum group metal ion by contacting such substrate with an aqueous solution containing the platinum group metal in an amount of 0.1-5% by weight of alumina substrate and a water soluble acid that forms RCOOH with R being an alkyl or equivalent, said acid being present in an amount of 10-120% by weight of the alumina substrate, the pH of said solution being less than 4.0; and (b) drying and calcining the wetted substrate without sintering said substrate.The three-way catalyst construction based on platinum group metals has enhanced catalytic activity. It comprises an alumina substrate and a platinum group metal impregnation layer thereover, said impregnation layer being comprised of raft-like particle structures, each having increased metal density resulting from the nesting of both small and large metal particles within a given volume.
    Type: Grant
    Filed: December 9, 1991
    Date of Patent: March 23, 1993
    Assignee: Ford Motor Company
    Inventors: Somasundaram Subramanian, William L. H. Watkins, Mohinder S. Chattha
  • Patent number: 5192517
    Abstract: Gas reacting apparatus and method are described for wet mass transfer of solute gases from a gas stream with a liquid or slurry reacting medium capable of chemisorption of solute gases in the gas stream. The apparatus comprises an elongated conduit means and plurality of dual-fluid spray means coaxially spaced in series within the conduit means and countercurrently or cocurrently directed to the gas stream for spraying the liquid or slurry reacting medium into the conduit means to form a plurality of spray contact zones or uniformly-distributed fine droplets in individual gas-liquid contact zones wherein intimate contact of high interfacial surface area between the sprayed liquid or slurry and the gas stream is effected to remove solute gases from the gas stream. The gas-liquid contact zones are separated by demisters which agglomerater and remove liquid droplets from the gas stream before it passes to the next zone. A demister also is provided at the outlet.
    Type: Grant
    Filed: January 28, 1991
    Date of Patent: March 9, 1993
    Assignee: Turbotak Inc.
    Inventor: Donald R. Spink
  • Patent number: 5192514
    Abstract: A method of removing gaseous selenium from a flue gas is disclosed. The method includes injecting an effective amount of ammonia into the flue gas to produce a solid selenium reaction product. The solid selenium reaction product is removed from the flue gas by undergoing deposition in a filter assembly. The filter assembly may then be cleaned through conventional methods.
    Type: Grant
    Filed: February 24, 1992
    Date of Patent: March 9, 1993
    Assignee: Electric Power Research Institute, Inc.
    Inventor: Edward B. Dismukes
  • Patent number: 5192516
    Abstract: A method for reducing the NO.sub.x produced by the engine of a supersonic aircraft. A reducing agent is injected into the combustor or the exhaust region of the engine. The reducing agent can be either hydrogen azide or hydrazine in an aqeuous form. For injection into the combustor, injection will be perpendicular to the main air flow through the engine and into a downstream portion of the combustor. Injection is carried out whenever NO.sub.x reduction is needed. By injecting the reducing agent into the downstream portion of the combustor or into the exhaust region, the reduction reaction is decoupled from the combustion process so that engine performance is not impaired.
    Type: Grant
    Filed: September 24, 1991
    Date of Patent: March 9, 1993
    Assignee: General Electric Company
    Inventor: Sanjay M. Correa
  • Patent number: 5188812
    Abstract: A method for controlling the phosphoric acid product concentration in a continuous phosphoric acid recovery process comprising supplying a constant feed stream of phosphate ore to an attack tank wherein the phosphate ore is subjected to attack by sulfuric and phosphoric acids to produce a slurry comprising an aqueous phosphoric acid solution and calcium sulfate, filtering the slurry to form aqueous phosphoric acid and calcium sulfate filter cake, rinsing said filter cake with water, and adding said rinse water to the attack tank, calculating a first amount of water required to maintain a desired concentration of phosphoric acid in the slurry, said desired concentration calculated based on the concentration of phosphate ore in the feed stream and the filterability of the filter cake, determining the total actual amount of water added to the attack tank, and adjusting the amount of rinse water so that the amount of water added to the attack tank is sufficient to maintain the desired concentration of phosphoric
    Type: Grant
    Filed: November 13, 1991
    Date of Patent: February 23, 1993
    Assignee: IMC Fertilizer, Inc.
    Inventor: Stephen W. Hilakos
  • Patent number: 5188811
    Abstract: This invention relates to additives to mixed-metal oxides that act simultaneously as sorbents and catalysts in cleanup systems for hot coal gases. Such additives of this type, generally, act as a sorbent to remove sulfur from the coal gases while substantially simultaneously, catalytically decomposing appreciable amounts of ammonia from the coal gases.
    Type: Grant
    Filed: February 26, 1992
    Date of Patent: February 23, 1993
    Assignee: General Electric Company
    Inventor: Raul E. Ayala
  • Patent number: 5186914
    Abstract: An activated carbon has a pencil hardness of B-6B, pore size of 100-400.ANG., specific surface area of 150-500 m.sup.2 /g, pore volume of 1.3-5.0 ml/g, and if desired, CEC of 8-13 and is composed of carbon microcrystals irregularly arranged.The activated carbon can be produced by burning waste tires containing metal wires. The activated carbon can be used for removing SO.sub.2 and/or Nox formed by combuation of heavy oil.
    Type: Grant
    Filed: March 15, 1991
    Date of Patent: February 16, 1993
    Assignee: The Social Welfare Foundation Hokkaido Rehability
    Inventors: Ikenaga Yoshihiro, Kobata Takeji
  • Patent number: 5186917
    Abstract: The present invention concerns a particulate agent for chemical and/or physical treatment of a fluid, such as a gas containing NO.sub.x and SO.sub.x, contains at least two particle types of different activity, the particle weight and/or particle size of each type lying within separate ranges. The agent may also contain catalyst particles for reducing NO.sub.x, and particles for absorbing SO.sub.x.The invention also concerns a method and a plant for treating a fluid with the inventive particulate agent.
    Type: Grant
    Filed: February 7, 1991
    Date of Patent: February 16, 1993
    Assignee: Eka Nobel AB
    Inventors: Sven G. Jaras, Marek T. Tokarz, Borje Persson
  • Patent number: 5185135
    Abstract: A digested slurry from a wet process phosphoric acid production process is dewatered by gravity-assisted vacuum filtration using as a filtration aid an aqueous solution of a polymeric filtraton aid that has been subjected to high shear mixing to enhance the performance of the filtration aid and enhance the filtration.
    Type: Grant
    Filed: August 12, 1991
    Date of Patent: February 9, 1993
    Assignee: Nalco Chemical Company
    Inventors: Krishnan J. Pillai, Lawrence J. Connelly, William K. Gustafson
  • Patent number: 5180565
    Abstract: A method of reducing the NO content of a gas stream comprises contacting the gas stream with an amount of HNCO at a temperature effective for heat-induced decomposition of HNCO, said amount and temperature being effective for resultant lowering of the NO content of the gas stream, said solid agent being particulate and having a particle size of less than 90 .mu.m.
    Type: Grant
    Filed: March 12, 1990
    Date of Patent: January 19, 1993
    Inventor: Robert A. Perry
  • Patent number: 5180567
    Abstract: The present invention provides an exhaust gas treating method by which exhaust gas is passed through a catalyst layer at an areal velocity of 100 to 5000 m.sup.3 /m.sup.2 .multidot.hr to selectively produce carbon monoxide from particulates contained in the exhaust gas, so that nitrogen oxides contained in the exhaust gas are removed by the carbon monoxide thus produced. The exhaust gas treating method of the present invention can readily and securely remove particulates and nitrogen oxides contained in exhaust gas, i.e., two primary causes of air pollution, by merely passing the exhaust gas through a catalyst layer at a specific areal velocity.
    Type: Grant
    Filed: March 7, 1991
    Date of Patent: January 19, 1993
    Assignee: Sakai Chemical Industry Co., Ltd.
    Inventors: Masafumi Yoshimoto, Tadao Nakatsuji, Kimihiko Yoshida
  • Patent number: 5180566
    Abstract: In order to remove ammonia from water vapor-containing gases, in particular offgases, the gases are brought into intimate contact with warmed polyphosphoric acid, the polyphosphoric acid advantageously having a P.sub.2 O.sub.5 content of from 70 to 84% by weight and a temperature of from 120.degree. to 170.degree. C.
    Type: Grant
    Filed: July 17, 1991
    Date of Patent: January 19, 1993
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Thomas Staffel, Renate Adrian
  • Patent number: 5176887
    Abstract: A three-way catalyst system for treating the exhaust stream of a compressed natural gas (CNG) fueled engine operating slightly rich of stoichiometry, the said catalyst system providing high conversions and low light-off temperature for the remnoval of HC, CO, and NO.sub.x. A high surface area gamma alumina support is impregnated with an intimate mixture of 0.2-30% Pd and 0.5-20% La.sub.2 O.sub.3, the Pd being in crystalline form with a particle size in the range of 5.500 angstroms.A method of making such catalyst system comprising sequentially impregnating a high surface area gamma alumina support with lanthana and palladium by incipient wetness techniques, such techniques comprising the procedure of contacting alumina first with a lanthanum nitrate solution of desired concentration to obtain 0.5-20% lanthana, contacting the lanthana impregnated alumina with a palladium nitrate solution of desired concentration to obtain a 0.
    Type: Grant
    Filed: October 7, 1991
    Date of Patent: January 5, 1993
    Assignee: Ford Motor Company
    Inventors: Somasundaram Subramanian, William L. H. Watkins, Mohinder S. Chattha
  • Patent number: 5176888
    Abstract: The process of this invention will remove acid rain precursors, sulfur oxides (SOX) and nitrogen oxides (NOX) by catalytically reducing the NOX to water and elemental nitrogen and the SOX to either H.sub.2 S or elemental sulfur as desired. The process employs specific catalysts in the heteropoly acid or salt group and the spinel or inverse spinel group. The process conditions achieve an oxygen-free environment and reduction is effected with stoichiometric to 100% excess above stoichiometric H.sub.2 or H.sub.2 and CO as reducing gas. Temperatures can be 200.degree. to 900.degree. C. with the lower temperature range being favored space velocity can be 2000 to 20,000 and still achieve 95+% abatement. The only product of the reaction which must be disposed of is saleable elemental sulfur.
    Type: Grant
    Filed: May 1, 1991
    Date of Patent: January 5, 1993
    Assignee: University of Delaware
    Inventor: Alvin B. Stiles
  • Patent number: 5173279
    Abstract: A process is shown for treating flue or exhaust gases in order to remove sulfur oxides and hydrochloric acids in which calcium hydroxide having a surface area of at least 25 m.sup.2 /g and a moisture content lower than 50% is injected in the gases to be treated either alone, or in a mixture with magnesium hydroxide. The calcium hydroxide used in the process is prepared by reacting quicklime or dolomitic quicklime with water in the presence of a glycol or an amine companion additive.
    Type: Grant
    Filed: November 21, 1990
    Date of Patent: December 22, 1992
    Assignee: Lhoist Recherche et Developpement S.A.
    Inventors: Philippe A. Dumont, Robert Goffin
  • Patent number: 5173280
    Abstract: A method for clarifying phosphoric acid by flocculation or coagulation of solids wherein an effective amount of a polymer having a predominantly sulfonic functionality is used as the clarification aid. Preferred polymers are high molecular weight acrylamide/acrylamido methylpropyl sulfonic acid-type (AM/AMPSA) polymers which are predominantly AMPSA.
    Type: Grant
    Filed: October 15, 1921
    Date of Patent: December 22, 1992
    Assignee: Calgon Corporation
    Inventors: Paul A. Rey, Wood E. Hunter
  • Patent number: 5173278
    Abstract: A flue gas that contains small amounts of both HCN and NO.sub.x, produced, for example, by catalyst regeneration in the fluid catalytic cracking of a petroleum gas oil, is readily denitrified by the catalyzed reaction that proceeds approximately according to:HCN+NO.fwdarw.N.sub.2 (gas)+CO+CO.sub.2 +H.sub.2 OIf the molar ratio of HCN to NO in the flue gas is about 1.0, e.g. in the range of about 0.8 to 1.2, effective denitrification is achieved without first changing the composition of the flue gas by contacting it with catalyst under conversion conditions including elevated temperature. If the molar ratio of HCN to NO exceeds 1.2, the ratio may be adjusted to about 1.0 to 1.1 by thermal or catalytic oxidation in the presence of oxygen gas, followed by catalytic denitrification. If the molar ratio is less than about 0.8, the effective molar ratio is adjusted to about 1.0 to 1.1 by adding NH.sub.3 gas, followed by denitirification.
    Type: Grant
    Filed: March 15, 1991
    Date of Patent: December 22, 1992
    Assignee: Mobil Oil Corporation
    Inventors: David O. Marler, Ajit V. Sapre, David S. Shihabi, Richard F. Socha, Scott A. Stevenson
  • Patent number: 5171558
    Abstract: A method is described for decomposing cyanuric acid at temperatures of less than about 1000.degree. F., and the method comprises heating the cyanuric acid in the presence of a decomposition catalyst which is effective at below about 1000.degree. F. Examples of useful decomposition catalysts are zirconium, phosphorus and mixtures thereof. Preferably at least some of the zirconium or phosphorus is in the plus four oxidation state. A method also is described for reducing the nitrogen oxide content of gas streams which comprises contacting the gas streams containing nitrogen oxide with an amount of the gaseous decomposition product mixture obtained by decomposing cyanuric acid in the presence of a decomposition catalyst at a temperature of less than about 1000.degree. F.
    Type: Grant
    Filed: September 27, 1991
    Date of Patent: December 15, 1992
    Assignee: Molecular Technology Corporation
    Inventors: Ralph A. Gardner-Chavis, Michael P. May
  • Patent number: 5171548
    Abstract: A process for removal of vanadium from wet process phosphoric acid comprising the steps of;(i) adsorbing an anionic pentavalent complex of vanadium, derived from the wet process phosphoric acid, onto an anion exchange resin or into an organic layer; and(ii) reducing the vanadium complex to trivalent and/or tetravalent vanadium so as to selectively strip vanadium from the anion exchange resin or from the organic layer.
    Type: Grant
    Filed: June 6, 1990
    Date of Patent: December 15, 1992
    Assignee: Advanced Separation Technologies Incorporated
    Inventors: Gordon J. Rossiter, Stephen F. Pease, Charles B. Snyder