Patents Examined by Gregory A. Heller
  • Patent number: 5219543
    Abstract: The process of removing dust, sulfur compounds and nitrogen oxides from combustion exhaust gases, comprising mixing a combustion exhaust gas with ammonia; feeding Ca(OH).sub.2 and FeSO.sub.4 to a fluidized bed reactor containing mixed solids including fly ash, iron sulfates and calcium compounds, especially Ca(OH).sub.2, CaCO.sub.3, CaO, CaSO.sub.4 and CaSO.sub.3 ; supplying an ammonia-containing exhaust gas mixture to the fluidized bed reactor as a fluidizing gas; operating the fluidized bed reactor at a temperature between and C. to form a reacted exhaust gas; supplying the reacted exhaust gas to a multistage electrostatic precipitator having a first stage and additional stages; recycling solids collected in the first stage to the fluidized bed reactor; and recycling one portion of additional solids collected in the additional stages to the fluidized bed reactor and discharging another portion of the additional solids.
    Type: Grant
    Filed: December 5, 1991
    Date of Patent: June 15, 1993
    Assignee: Metallgesellschaft Aktiengesellschaft
    Inventors: Werner Weisweiler, Erhard Herrmann, Wolfgang Fennemann, Harald Sauer, Bernd Thone
  • Patent number: 5219545
    Abstract: A catalyst and a method for catalytically decomposing nitrogen oxides, wherein the catalyst comprises a zeolite having a mole ratio of SiO.sub.2 /Al.sub.2 O.sub.3 of at least 20, and containing (i) copper ions and (ii) (a) transition metal ions other than copper ions, (b) at least one alkaline earth metal ion selected from calcium, strontium and barium ions, (c) yttrium ions, or (a) silver ions.
    Type: Grant
    Filed: March 8, 1991
    Date of Patent: June 15, 1993
    Assignee: Tosoh Corporation
    Inventors: Shuichi Kagawa, Yasutake Teraoka
  • Patent number: 5219542
    Abstract: A novel composition comprising zinc oxide, zinc phosphate and, optionally, alumina is described which can effectively be used to remove sulfur compounds from a fluid stream by contacting said fluid stream under suitable absorption conditions with the novel composition. A novel method of producing an absorption composition is described where the steps include the formation of a composition comprising zinc oxide, zinc phosphate and, optionally, alumina.
    Type: Grant
    Filed: July 10, 1991
    Date of Patent: June 15, 1993
    Assignee: Phillips Petroleum Company
    Inventors: Richard E. Lowery, Donald R. Engelbert
  • Patent number: 5219544
    Abstract: The invention relates to a method of purifying the exhaust gases from plants for the production of cement clinker, in which the filter zone through which the exhaust gases flow contains at least one adsorption stage in which an adsorbent is provided which is suitable for fixing NH.sub.x compounds, heavy metals and/or trace pollutants, at least a proportion of the adsorbent being removed from the adsorption stage at specific intervals of time and introduced into the final burning zone and/or preheating zone. By such a method the NO.sub.x content of the exhaust gases is significantly reduced, and at the same time heavy metals and trace pollutants are eliminated from the exhaust gases.
    Type: Grant
    Filed: December 20, 1990
    Date of Patent: June 15, 1993
    Assignee: Krupp Polysius AG
    Inventors: Detlev Kupper, Ludger Brentrup, Wolfgang Rother
  • Patent number: 5213778
    Abstract: A method for treating the combustion gases produced by the incineration of industrial waste and the like is disclosed wherein the gases are sprayed with H.sub.2 O to form a saturated aqueous vapor that absorbs the noxious materials in the gases, and wherein the vapor is then sprayed with neutralizing agent as it passes through a succession of neutralizing chambers.
    Type: Grant
    Filed: July 24, 1990
    Date of Patent: May 25, 1993
    Assignee: Yuichi Sato
    Inventor: Inomatsu Sato
  • Patent number: 5213782
    Abstract: An improved magnesium-enhanced lime flue gas desulfurization system and process are provided which produce the high sulfur dioxide removal level of previous magnesium-enhanced lime flue gas desulfurization systems and additionally produce waste solids that have significantly better properties and are more easily dewatered than the solids produced by known systems. The magnesium-enhanced lime flue gas desulfurization system of the present invention includes a crystallizer-clarifier reaction tank (CCRT) which receives scrubber effluent and functions as a combined reaction tank and thickener. Clear liquor from the CCRT is sent to a scrubber to scrub the flue gas, and a portion of the CCRT-thickened solids are directed to a high pH premix slurry tank (PMST) where the crystallization environment can be controlled by reagent addition and pH. The PMST contents are circulated to the CCRT and are separated to produce a waste solids fraction that is easily dewatered.
    Type: Grant
    Filed: November 22, 1991
    Date of Patent: May 25, 1993
    Assignee: Electric Power Research Institute
    Inventors: Robert E. Moser, James H. Wilhelm, John Burke, Sterling Gray
  • Patent number: 5213781
    Abstract: An exhaust gas cleaner comprising a heat-resistant, porous filter, a porous ceramic layer formed on the filter, and a catalyst supported by the ceramic layer, the catalyst consisting essentially of:(a) at least one of alkali metal elements;(b) copper and vanadium; and(c) at least one of rare earth elements.By using this exhaust gas cleaner, particulate matter in the exhaust gas is oxidized by the catalyst supported by the filter, and nitrogen oxides are reduced by the particulate matter serving as a reducing agent.
    Type: Grant
    Filed: October 8, 1991
    Date of Patent: May 25, 1993
    Assignee: Kabushiki Kaisha Riken
    Inventors: Akira Abe, Satoshi Sumiya, Yoshikazu Takahashi, Kiyohide Yoshida, Gyo Muramatsu
  • Patent number: 5213779
    Abstract: A process for optimizing the removal of nitrogen oxide (NO.sub.x) and sulfur oxide (SO.sub.X) from flue gases is provided in which the flue gases pass over a lanthanide-oxygen-sulfur catalyst. The catalyst has active sites provided on its surface which promote the dissociation of NO.sub.X and receive and entrap oxygen released during the dissociation of the NO.sub.X. While the flue gases pass over the catalyst, a reducing gas contacts the catalyst to reduce the oxygen on the active sites of the catalyst and permit the catalyst to continue to promote the dissociation of the NO.sub.x in the flue gas. If the flue gases contain SO.sub.X, they are then passed over a solid solution having a solvent of a first lanthanide oxide compound which crystallizes in the fluorite habit and a solute of at least one altervalent oxide of a second lanthanide. The SO.sub.X in the flue gases reacts with the solid solution to form a sulfated lanthanide oxide which is removed from the flue gases.
    Type: Grant
    Filed: August 1, 1991
    Date of Patent: May 25, 1993
    Assignee: Gas Desulfurization Corporation
    Inventors: D. Alan R. Kay, William G. Wilson, Vinod Jalan
  • Patent number: 5213780
    Abstract: The present invention pertains to a method for nitrogen oxide reduction and flue gas reheating wherein a catalyst surface is heated to an operating temperature to facilitate a catalytic reduction reaction in the presence of relatively cool flue gas. To avoid conventional complication the catalytic reduction reaction is performed downstream of both particulate control operations and desulfurization procedures. That is, the catalyst surface itself is placed just before the stack. The method of the present invention reheats the flue gas prior to its exit into the atmosphere.
    Type: Grant
    Filed: June 4, 1991
    Date of Patent: May 25, 1993
    Assignee: Research-Cottrell, Inc.
    Inventor: Dennis J. Helfritch
  • Patent number: 5211925
    Abstract: A method for removing nitrogen oxides NO.sub.x and volatile organic combustibles VOC's from impure air or gases is provided. The method includes the steps of admixing ammonia or other reducing gas to the feed of an incinerator, heating the gas to about F., reacting the NO.sub.x with the reducing gas to form nitrogen gas and water, and further heating the gas to oxidize the VOC's and residual reducing gas with the oxygen present.
    Type: Grant
    Filed: February 11, 1992
    Date of Patent: May 18, 1993
    Inventor: Reagan Houston
  • Patent number: 5211928
    Abstract: A method for improving gypsum slurry filtration in the production of wet process phosphoric acid wherein an effective amount of carboxylic-type polymer having a portion of sulfonic functionality is used as the filtration aid. Preferred polymers are high molecular weight polymers of acrylic acid and acrylamido methylpropyl sulfonic acid.
    Type: Grant
    Filed: October 15, 1991
    Date of Patent: May 18, 1993
    Assignee: Calgon Corporation
    Inventors: Paul A. Rey, Wood E. Hunter
  • Patent number: 5211926
    Abstract: In order to recover or dispose of ammonia or ammonia compounds from mixtures of dust that occur during combustion processes, during subsequent gas cooling, or during subsequent gas scrubbing, the dust that is created is mixed in batches with water in a closed system at a temperature that is lower or equal to the temperature at which the dust leaves the combustion, cooling or scrubbing process, and the resulting vapors are drawn off in a vacuum.
    Type: Grant
    Filed: December 20, 1991
    Date of Patent: May 18, 1993
    Assignees: Martin GmbH fur Umwelt- und Energietechnik, Techform Engineering AG
    Inventors: Walter J. Martin, Johannes J. E. Martin, Stefan Horler, Thomas Nikolaus
  • Patent number: 5209915
    Abstract: A method of removing sulphur oxides from flue gases comprises atomizing a wet alkali slurry into a slurry spray. A pneumatically conveyed dry reactive recycled flyash is supplied in an annular pattern around the slurry spray to efficiently utilize the flyash without experiencing difficulties which were experienced in the prior art with regard to a wet mixture of the flyash.
    Type: Grant
    Filed: October 10, 1990
    Date of Patent: May 11, 1993
    Assignee: The Babcock & Wilcox Company
    Inventor: John H. Kidwell
  • Patent number: 5209912
    Abstract: A composition for separating out volatile pollutants from gases and exhaust gases consists of calcium hydroxide and water-soluble salts of sulfur-containing compounds, e.g., mercaptans, sulfides, polysulfides, polythionates and thiosulfates, or elementary sulfur which are used in combination with surface-active substances.Possible ways to produce the composition include adding the sulfur-containing compounds to the quicklime during slaking, to the slaking water, or, subsequent to slaking, to calcium hydroxide.The compositions are used for removing the volatile heavy metals, particularly mercury, arsenic, cadmium, thallium, antimony and lead, at temperatures ranging from to C. For this purpose, the composition is blown as powder into the exhaust gas stream, and the resultant products are separated out at fabric filters. Upon addition of surface-active substances, volatile organic pollutants are removed simultaneously with the aforementioned inorganic pollutants.
    Type: Grant
    Filed: May 2, 1990
    Date of Patent: May 11, 1993
    Assignee: FTU GmbH
    Inventor: Hermann Suchenwirth
  • Patent number: 5206002
    Abstract: Exhaust gases containing oxides of nitrogen and sulfur from a fired process heater, a fossil fuel fired boiler, or a chemical process are diverted from a stack prior to admission to the atmosphere through a duct system containing heat exchangers that reduce the exhaust gas from an elevated temperature, if any, to about ambient temperature. Any heat extracted from the exhaust gas may be transferred to the boiler feed water which would serve to reduce the energy cost of operating a boiler. Once the exhaust gas is cooled to about ambient temperature, the gas is then mixed with an oxidant, such as ozone, at a preselected molar ratio to transform the oxides to higher orders of nitrogen and sulfur oxides to increase the absorbability of the nitrogen and sulfur oxides in a reagent solution. The reagent absorbs the oxidized contaminants from the exhaust gas. The oxides are transformed to dilute acids which are then neutralized to form salts that are acceptable for discharge to a municipal waste water treatment plant.
    Type: Grant
    Filed: August 29, 1991
    Date of Patent: April 27, 1993
    Assignee: Cannon Boiler Works, Inc.
    Inventors: Arthur P. Skelley, James C. McMichael, James T. Cobb, Jr., Wesley M. Rohrer, Jr., Phillip E. Custer, II, Taha M. Elsubki
  • Patent number: 5202101
    Abstract: A process and system for simultaneously removing from a gaseous mixture, sulfur oxides by means of a solid sulfur oxide acceptor on a porous carrier, nitrogen oxides by means of ammonia gas and particulate matter by means of filtration and for the regeneration of loaded solid sulfur oxide acceptor. Finely-divided solid sulfur oxide acceptor is entrained in a gaseous mixture to deplete sulfur oxides from the gaseous mixture, the finely-divided solid sulfur oxide acceptor being dispersed on a porous carrier material having a particle size up to about 200 microns. In the process, the gaseous mixture is optionally pre-filtered to remove particulate matter and thereafter finely-divided solid sulfur oxide acceptor is injected into the gaseousThe government of the United States of America has rights in this invention pursuant to Contract No. DE-AC21-88MC 23174 awarded by the U.S. Department of Energy.
    Type: Grant
    Filed: June 23, 1992
    Date of Patent: April 13, 1993
    Assignee: General Electric Environmental Services
    Inventors: Mitchell R. Cohen, Eli Gal
  • Patent number: 5202103
    Abstract: Processes are provided for the removal of sulfur dioxide from gas streams using aqueous lime or limestone slurries containing an additive comprising an amine. The amines have an available alkalinity of at least 0.5 meq/gram at a pH between 3.0 and 5.5. The amines are highly soluble in the slurry and can have a low volatility, thereby reducing amine losses with the gas product. Furthermore, amines which are absorbed on the calcium sulfate or calcium sulfite by-products can be recovered by water-washing with a water make-up stream.
    Type: Grant
    Filed: December 20, 1991
    Date of Patent: April 13, 1993
    Assignee: Union Carbide Chemicals & Plastics Technology Corporation
    Inventors: John C. Chang, Leo E. Hakka, Veronique Roy
  • Patent number: 5200161
    Abstract: A process is disclosed for the separation of hydrogen cyanide from gases and waste gases by a throughflow or circulation scrubbing, in which formaldehyde is added at a controlled rate to the aqueous scrubbing liquid to form glycol nitrile. This addition is controlled by measuring the HCN tension in a measuring stream which has been branched off and which is first treated with hydrogen peroxide so that free H.sub.2 O.sub.2 is still detectable after 1 to 100 seconds and the pH is adjusted to a constant value before measurement of the HCN tension is carried out. The process prevents overdosing with formaldehyde which could not always be prevented in previously known processes in which the addition of formaldehyde was regulated by measuring the cyanide specific redox potential.
    Type: Grant
    Filed: May 6, 1992
    Date of Patent: April 6, 1993
    Assignee: Degussa Aktiengesellschaft
    Inventors: Joachim Fischer, Hubert Wolf, Manfred Diehl
  • Patent number: 5200162
    Abstract: The exothermicity attending decomposition of N.sub.2 O to nitrogen and oxygen can lead to a multiplicity of process difficulties associated with high process temperatures. An improved process is one where a portion of the exit gases, depleted in N.sub.2 O, is first cooled and then recycle to the N.sub.2 O-decomposition zone. The process is amenable to process control to afford a very stable process largely independent on the particular catalyst used for N.sub.2 O decomposition. Where the N.sub.2 O-containing waste gas stream also contains NO.sub.x, if it often highly desirable to pretreat the stream to remove NO.sub.x prior to the N.sub.2 O-decomposition zone.
    Type: Grant
    Filed: April 1, 1992
    Date of Patent: April 6, 1993
    Assignee: UOP
    Inventors: Brian W. Riley, John R. Richmond
  • Patent number: 5198206
    Abstract: When condensing sulfuric acid from gases containing sulfuric acid vapor and steam in excess, e.g. originating from a power station, a substantial decrease of the amount minute droplets of sulfuric acid (the so-called acid mist) escaping to the surroundings is obtained, even in cases where the sulfuric acid plant is equipped with an aerosol filter, if minute nucleation cores are incorporated into the gas in an amount of 10.sup.9 to 10.sup.12 solid particles per Nm.sup.3 per 0.1 % H.sub.2 SO.sub.4 -vapor in the gas. The nucelation cores may, e.g., be generated by combusting hydrocarbons with>2 carbon atoms or silicones, or added as smoke from an electric arc or welding.
    Type: Grant
    Filed: December 6, 1990
    Date of Patent: March 30, 1993
    Assignee: Haldor Topsoe A/S
    Inventor: Peter Schoubye