Purifying Acid Or Reactant Patents (Class 423/531)
  • Patent number: 10640376
    Abstract: Sulfur trioxide is produced from a feed stream comprising sulfur-containing compounds and dissolved metals, such as alkali metals, in a plant comprising an incineration furnace, a waste heat boiler, a dilution air heater, a dust removal absorber and an SO2 converter. The plant may further comprise a sulfuric acid condenser for the production of sulfuric acid.
    Type: Grant
    Filed: July 4, 2017
    Date of Patent: May 5, 2020
    Assignee: Haldor Topsoe A/S
    Inventors: Morten Thellefsen, Martin Møllerhøj
  • Patent number: 9156716
    Abstract: A method for the purification of spent sulfuric acid and particularly the purification of spent acid, from titanium dioxide rutile manufacture through a chloride route, is provided. In the chloride route of titanium dioxide manufacture, sulfuric acid is used to clean the un-reacted gaseous flow coming out of the oxidizer, so the spent acid mainly contains un-reacted Ti4+ ions, trace amounts of Fe3+ ions, and NO2 gas. Titanium phosphate can be precipitated using acidic and or alkaline phosphate-containing precipitants in stoichiometric amounts. The method can include the addition of cutting water. NO2 gas evolved during the reaction can be scrubbed in water. The resulting aqueous acid-rich portion, or supernatant, can be separated from the precipitated phosphates and is very clear. Evaporation under vacuum conditions can increase the sulfuric acid concentration. The resultant purified acid can be re-used.
    Type: Grant
    Filed: January 8, 2015
    Date of Patent: October 13, 2015
    Assignee: The National Titaniun Dioxide Co., Ltd. (CRISTAL)
    Inventors: Ahmed Yasir Vakayil, Rene Jongen, Ahmad I. Jomha
  • Patent number: 8906133
    Abstract: A process for cooling an acid that is withdrawn from an absorption apparatus of a sulfuric acid plant includes pumping the acid to be cooled from an acid pump tank and supplying the acid to a shell space of a heat exchanger. Water is supplied as a heat transport medium to heat transfer elements disposed in the shell space so as to at least partially convert, by heat transfer from the acid, the water to steam. The acid which was cooled in the heat exchanger is supplied back to the absorption apparatus. The water is separated from the steam in a steam drum. The separated water is recirculated to the heat exchanger using a pump.
    Type: Grant
    Filed: January 11, 2011
    Date of Patent: December 9, 2014
    Assignee: Outotec Oyj
    Inventors: Karl-Heinz Daum, Wolfram Schalk
  • Patent number: 8815202
    Abstract: A process for producing sulfuric acid with reduced levels of nitrogen oxides (NOx) within a typical sulfuric acid production line. A hydrazine source material can be mixed with a sulfuric acid effluent at a temperature of at least about 90° C. for a period of at least 1 minute to reduce the level of NOx is the sulfuric acid effluent.
    Type: Grant
    Filed: August 19, 2013
    Date of Patent: August 26, 2014
    Assignee: E I du Pont de Nemours and Company
    Inventors: Hasan Dindi, Donald James Loftus
  • Patent number: 8772565
    Abstract: A radioactive waste acid is recycled. The waste acid is a fluoboric waste acid. The waste acid contains a lot of oxides and radioactive nuclei. The waste fluoboric acid is processed to obtain a purified fluoboric acid. The amount of radioactive nuclei is greatly reduced. Thus, the present invention has a simple procedure with low cost and reduced power consumption.
    Type: Grant
    Filed: July 3, 2013
    Date of Patent: July 8, 2014
    Assignee: Institute of Nuclear Energy Research, Atomic Energy Council
    Inventors: Chin-Hsiang Kan, Wen-Cheng Lee, Tsong-Yang Wei
  • Patent number: 8709376
    Abstract: Disclosed is a process for the extractive recovery of an acid catalyst from an aqueous mixture of glycolic acid with an extraction solvent comprising a tertiary amine or an onium carboxylate compound, a modifier, and a diluent. The acid catalyst, which can comprise strong acids such as sulfuric acid, alkyl sulfonic acids, and fluoroalkyl sulfonic acids, can be recovered by back extraction with aqueous formaldehyde and recycled to a process for the preparation of glycolic acid by the acid-catalyzed carbonylation of formaldehyde.
    Type: Grant
    Filed: September 23, 2010
    Date of Patent: April 29, 2014
    Assignee: Eastman Chemical Company
    Inventors: Scott Donald Barnicki, Stephen Neal Falling, Jeffrey Scott Kanel, Robert Sterling Kline, Peter Borden Mackenzie
  • Publication number: 20140056802
    Abstract: A process for producing sulfuric acid with reduced levels of nitrogen oxides (NOx) within a typical sulfuric acid production line. A hydrazine source material can be mixed with a sulfuric acid effluent at a temperature of at least about 90° C. for a period of at least 1 minute to reduce the level of NOx is the sulfuric acid effluent.
    Type: Application
    Filed: August 19, 2013
    Publication date: February 27, 2014
    Applicant: E I DU PONT DE NEMOURS AND COMPANY
    Inventors: Hasan Dindi, Donald James Loftus
  • Patent number: 8603420
    Abstract: The invention enables processing waste sludge after galvanic treatment of metals, and particularly recycling spent pickling acids after pickling. Provided is an environmentally friendly process, which yields acids for reuse, and pure nano-sized iron pigments as a side product.
    Type: Grant
    Filed: September 7, 2010
    Date of Patent: December 10, 2013
    Assignee: Green Future Ltd.
    Inventors: Vladimir Boiko, Reuben Schapiro
  • Publication number: 20130302240
    Abstract: A method for the purification of spent sulfuric acid and particularly the purification of spent acid, from titanium dioxide rutile manufacture through a chloride route, is provided. In the chloride route of titanium dioxide manufacture, sulfuric acid is used to clean the un-reacted gaseous flow coming out of the oxidizer, so the spent acid mainly contains un-reacted Ti4+ ions, trace amounts of Fe3+ ions, and NO2 gas. Titanium phosphate can be precipitated using acidic and or alkaline phosphate-containing precipitants in stoichiometric amounts. The method can include the addition of cutting water to commence the precipitation in two or more steps, when an acidic precipitant is used, and in one step with half the volume of water when an alkaline precipitant is used.
    Type: Application
    Filed: May 10, 2012
    Publication date: November 14, 2013
    Applicant: THE NATIONAL TITANIUM DIOXIDE CO. LTD. (CRISTAL)
    Inventors: Ahmed Yasir VAKAYIL, Rene JONGEN, Ahmad I. JOMHA
  • Publication number: 20120301389
    Abstract: The present invention provides an organic phase composition comprising (a) a first solvent (S1) characterized by water solubility of less than 10% and by at least one of (a1) having a polarity related component of Hoy's cohesion parameter (delta-P) between 5 and 10 MPa1/2 and (b1) having a Hydrogen bonding related component of Hoy's cohesion parameter (delta-H) between 5 and 20 MPa1/2; (b) a second solvent (S2) characterized by a water solubility of at least 30% and by at least one of (a2) having delta-P greater than 8 MPa1/2 and (b2) having delta-H greater than 12 MPa1/2; (c) water; (d) a non-volatile strong acid; and (e) a salt thereof.
    Type: Application
    Filed: February 6, 2011
    Publication date: November 29, 2012
    Applicants: ASHER VITNER LTD., EYAL RESEARCH CONSULTANTS LTD.
    Inventors: Aharon Eyal, Asher Vitner, Revital Mali, Carmi Raz
  • Publication number: 20110129410
    Abstract: “METHOD FOR RECYCLING USED LEAD ACID BATTERIES ELECTROLYTIC SOLUTION”, especially the automotive batteries, has the following stages: the sulfuric acid solution derived from the cutting of batteries goes through a drying bed (quick filters) which is composed of a layer of crushed rocks, “bidim” and sand or through a press filter for the retaining of the solid particles, after the solution goes through these filters, it goes through to a reactor where it suffers a forced decantation process for retaining the heavy metals and contaminants; the forced decantation process is carried out by adding 20 liters of aluminum dioxide, 20 kilos of lime (in the form of milk of lime), 2 liters of aluminum polychloride (flocculent) and 200 grams of acrylic acid acrylamide (polymer, used diluted in water) to every 10,000 liters of sulfuric acid under shaking, it is then left at rest for 40 minutes for decantation, soon after decantation the floating part goes through a bag filter with a polyethylene sheet filter and then thro
    Type: Application
    Filed: May 27, 2009
    Publication date: June 2, 2011
    Inventor: Almir Dos Santos Trindade
  • Patent number: 7842272
    Abstract: Sulfuric acid contaminated with byproducts of chloromethane scrubbing is regenerated for reuse in the scrubbing process by diluting with water to not lower than about a 55 weight percent concentration, heating the diluted acid to boiling at not more than about 135° C., concentrating the acid to a concentration of minimally 80 weight percent at a temperature of at least 170° C., and reacting the concentrated acid with an oxidizing agent.
    Type: Grant
    Filed: October 6, 2006
    Date of Patent: November 30, 2010
    Assignee: Wacker Chemie AG
    Inventors: Klaus Kaeppler, Reinhold Iretzberger, Gerhard Nagy
  • Publication number: 20100284900
    Abstract: A method for recovering sulfuric acid from concentrated acid hydrolysate of plant cellulose material is disclosed. In some of the examples, the concentrated acid hydrolysate is mixed with a liquid organic precipitant, thereby the sugars in the hydrolysate is precipitated and separated out, and the remained is sulfuric acid and an organic solvent solution. Then the organic solvent is separated by distillation or extraction, thereby obtaining the pure sulfuric acid solution. This precipitation method can recover above 90% sugars and acids with a small amount of organic precipitant, which greatly reduces the recover cost.
    Type: Application
    Filed: July 29, 2008
    Publication date: November 11, 2010
    Inventor: Peihao Chen
  • Publication number: 20100152517
    Abstract: A process for the regeneration of spent sulfuric acid including contacting spent sulfuric acid containing acid soluble oils (ASO) with sulfur dioxide to extract at least a portion of the ASO from the spent sulfuric acid into the sulfur dioxide. The sulfuric acid phase having a reduced ASO content and a sulfur dioxide phase containing at least a portion of the ASO may be recovered. The resulting sulfuric acid and sulfur dioxide phases may be further separated to recover ASO, sulfur dioxide, and sulfuric acid.
    Type: Application
    Filed: December 12, 2008
    Publication date: June 17, 2010
    Applicant: CATALYTIC DISTILLATION TECHNOLOGIES
    Inventor: William M. Cross, JR.
  • Patent number: 7682066
    Abstract: The recycling apparatus of waste sulfuric acid for collecting waste sulfuric acid generated at a source site A, transporting it by a carrier B, and recycling it for reuse at a user site C, the recycling apparatus of waste sulfuric acid including a receiving tank for receiving virgin sulfuric acid (a) and waste sulfuric acid (b) having a concentration different from that of the virgin sulfuric acid, and including (1) a mixer alone, (2) a mixer and a concentration monitor, or a mixer and a cooler in combination, or (3) a mixer, a concentration monitor, and a cooler in combination.
    Type: Grant
    Filed: November 28, 2003
    Date of Patent: March 23, 2010
    Assignee: Sony Corporation
    Inventor: Yasuhito Inagaki
  • Publication number: 20100015035
    Abstract: The invention relates to a method of producing sulfuric acid wherein an SO2-containing raw gas produced in a sulfuric-acid recovery plant is passed through at least one reactor in which a catalytic reaction of SO2 to SO3 takes place, and the SO3 thereby formed is converted into sulfuric acid. According to the invention, at least a partial stream of the gas stream leaving the sulfuric-acid recovery plant is hydrogenated with an H2-rich gas in a post-treatment stage. The H2S-containing gas stream formed by the hydrogenation is fed into the H2S gas scrubber of a coke oven plant or a petrochemical plant. The invention also relates to an installation for carrying out the method.
    Type: Application
    Filed: March 20, 2008
    Publication date: January 21, 2010
    Inventor: Holger Thielert
  • Publication number: 20090317321
    Abstract: Spent sulfuric acid is decomposed by atomizing it with an oxygen-containing stream into a decomposition furnace.
    Type: Application
    Filed: June 18, 2008
    Publication date: December 24, 2009
    Inventors: James Patrick Meagher, William Thoru Kobayashi, Maynard Guotsuen Ding, Lee Jonathan Rosen
  • Patent number: 7595035
    Abstract: Process for the recovery of sulfuric acid comprising: (a) contacting a stream containing sulfuric acid vapor and/or sulfur trioxide in an absorption stage with a ionic liquid absorbent, (b) withdrawing a gas substantially free of sulfuric acid vapor and/or sulfur trioxide from said absorption stage, (c) withdrawing a stream comprising the ionic liquid absorbent from said absorption stage, in which said ionic liquid absorbent contains sulfuric acid, (d) recovering sulfuric acid from said ionic liquid absorbent by passing the stream of step (c) through a separation stage, (e) withdrawing from the separation stage (d) a stream rich in sulfuric acid, (f) withdrawing from the separating step (d) a ionic liquid absorbent stream in which said ionic liquid absorbent contains sulfuric acid and returning said stream to the absorption step (a).
    Type: Grant
    Filed: June 4, 2007
    Date of Patent: September 29, 2009
    Assignee: Haldor Topsoe A/S
    Inventors: Sven Ivar Hommeltoft, Morten Thellefsen
  • Publication number: 20090226351
    Abstract: A supercritical oxidation process, which comprises pressurizing and heating an aqueous system to form a fluid phase under supercritical conditions, feeding an oxidizer into said fluid phase to cause an oxidation reaction therein, directing the resultant fluid reaction phase into a central region of a cooling chamber while providing a coolant in an internal peripheral region of said cooling chamber, said peripheral region being adjacent to the inner surface of the cooling chamber, mixing the fluid reaction phase with said coolant within the cooling chamber, removing the reaction mixture from said cooling chamber and subsequently further reducing the temperature and the pressure of said reaction mixture to obtain a product mixture.
    Type: Application
    Filed: February 6, 2007
    Publication date: September 10, 2009
    Inventor: Ariel Rosenberg
  • Patent number: 7537749
    Abstract: The invention concerns a method for processing heavy metal-laden spent sulfuric acid. For this, iron-laden spent sulfuric acid or iron-laden sulfuric materials obtained therefrom are reacted with a material that contains iron chloride and optionally other metal chlorides, producing iron (II) sulfate. The spent sulfuric acid preferably derives from titanium dioxide production.
    Type: Grant
    Filed: October 1, 2004
    Date of Patent: May 26, 2009
    Assignee: Tronox Pigments GmbH
    Inventors: Gerhard Auer, Berndt-Ullrich Köhler, Benno Laubach
  • Patent number: 7498007
    Abstract: A process for recovery of vanadium dissolved in acid solutions or liquors by precipitating it out as vanadium pentoxide. Separation is carried out by adding calcium hydroxide, quicklime or calcium carbonate to the acid solution or liquor, producing a precipitate of vanadium pentoxide, which is separated from the liquid by physical methods such as filtration or centrifugation. If the acid is other than sulfuric acid, the calcium which remains dissolved in the solution or liquor by the addition of calcium hydroxide, quicklime or calcium carbonate, is removed by adding sulfuric acid, to produce solid calcium sulfate and water. The calcium sulfate is extracted from the solution or liquor or liquor by filtration or centrifugation. With sulfuric acid solution or liquors, after addition of the neutralizing agent, a solid precipitate of vanadium pentoxide and calcium sulfate is formed, which is then separated from the solution or liquor.
    Type: Grant
    Filed: March 16, 2005
    Date of Patent: March 3, 2009
    Inventors: Benjamin Scharifker, Rossana Arenare
  • Patent number: 7473409
    Abstract: A recycling process is presented to treat spent waste acid solutions whereby useful products are produced. Spent waste acid containing inorganic and organic contaminants is mixed with a magnesium compound containing aluminum and iron compounds that form oxyhydroxide flocs that complex, react, sequester and/or co-precipate the contaminates from the admixture. The magnesium reacts with sulfate ions to form a high quality magnesium sulfate solution.
    Type: Grant
    Filed: August 30, 2006
    Date of Patent: January 6, 2009
    Assignee: Veolia ES Technical Solutions L.L.C.
    Inventor: Danny Mislenkov
  • Publication number: 20080293979
    Abstract: Sulfuric acid contaminated with byproducts of chloromethane scrubbing is regenerated for reuse in the scrubbing process by diluting with water to not lower than about a 55 weight percent concentration, heating the diluted acid to boiling at not more than about 135° C., concentrating the acid to a concentration of minimally 80 weight percent at a temperature of at least 170° C., and reacting the concentrated acid with an oxidizing agent.
    Type: Application
    Filed: October 6, 2006
    Publication date: November 27, 2008
    Applicant: WACKER CHEMIE AG
    Inventors: Klaus Kaeppler, Reinhold Iretzberger, Gerhard Nagy
  • Patent number: 7452521
    Abstract: This invention relates to a method for removing mercury from dilute sulphuric acid. According to the method sulphuric acid solution is scrubbed with an aqueous solution containing thiosulphate, which precipitates the mercury present in the sulphuric acid solution either as mercury sulphide or, in a chlorine-containing environment, as a mercury sulphide-mercury chloride double salt. The quantity of thiosulphate to be fed is adjusted so that it precipitates the mercury in the sulphuric acid solution, but still does not form elemental sulphur.
    Type: Grant
    Filed: July 16, 2004
    Date of Patent: November 18, 2008
    Assignee: Outotec OYJ
    Inventors: Dag Berg, Jens Nyberg, Aija Rytioja, Heljä Peltola, Pekka Taskinen
  • Patent number: 7442359
    Abstract: The invention is directed to a process for the recovery of sulphuric acid from a mixture comprising sulphuric acid and hydrocarbons, in particular carbohydrates. In accordance with the present invention the mixture comprising sulphuric acid and carbohydrates, is contacted with an anion selective membrane, thus producing a sulphuric acid rich filtrate stream and a stream depleted in sulphuric acid.
    Type: Grant
    Filed: August 10, 2007
    Date of Patent: October 28, 2008
    Assignee: Nederlandse Organisatie voor Toegepast-Natuurwetenschappelijk Onderzoek TNO
    Inventors: Johannes Wouterus Van Groenestijn, Jacob Hendrik Obbo Hazewinkel, Raymond Johannes Maria Creusen, Koen Peter Henri Meesters
  • Publication number: 20080175777
    Abstract: The present invention provides for process for inhibiting the levels of nitrogen oxides in process gas streams from sulfuric acid regeneration and production plants. The process gas stream from the waste heat boiler and the candle mist eliminator is contacted with ozone which will react with nitrogen oxides present in the flue gas.
    Type: Application
    Filed: January 10, 2008
    Publication date: July 24, 2008
    Inventors: Naresh Suchak, Steven Joseph Finley, Joseph A. Eschbach, Robert Zeiss
  • Patent number: 7360550
    Abstract: A system for recycling spent sulfuric acid, wherein spent sulfuric acid is effectively utilized at a place other than a discharge source regardless of geographical conditions, and a method for recycling waste sulfuric acid. In the system, when spent sulfuric acid that is discharged or collected at a discharge source is transported by a carrier unit and used at a user office a concentration of the spent sulfuric acid is measured and/or adjusted at least at one of the discharge source, the carrier unit, and the user office. The spent sulfuric acid waste liquid that is discharged or collected at the discharge source is reutilized by being mixed with at least one of a hydrogen peroxide solution and water.
    Type: Grant
    Filed: April 4, 2003
    Date of Patent: April 22, 2008
    Assignee: Sony Corporation
    Inventor: Yasuhito Inagaki
  • Patent number: 7351391
    Abstract: A system and method of economically converting a spent first pickling acid solution that contains hydrochloric acid, water and ferrous chloride into a suitable second pickling solution. Sulfuric acid is added to the first pickling acid solution. This produces a regeneration solution. In the regeneration solution, the sulfuric acid reacts with said ferrous chloride and water to produce ferrous sulfate heptahydrate and hydrochloric acid. The regeneration solution is cooled to promote precipitation of the ferrous sulfate heptahydrate from the regeneration solution, therein creating ferrous sulfate heptahydrate crystals and a second pickling acid solution. The second pickling acid solution contains both hydrochloric acid and sulfuric acid. The ferrous sulfate heptahydrate crystals are separated from second pickling solution. The ferrous sulfate heptahydrate is sold commercially and the second pickling acid solution is used to directly pickle ferrous metal.
    Type: Grant
    Filed: May 16, 2005
    Date of Patent: April 1, 2008
    Inventors: Douglas R. Olsen, Charles D. Blumenschein
  • Patent number: 7344692
    Abstract: A process for the regeneration of sulfuric acid contaminated with hydrocarbons and water to produce pure concentration acid comprising: contacting sulfuric acid contaminated with hydrocarbons and water with oxygen and elemental sulfur in the presence of a vanadium containing catalyst in a reaction zone, maintaining at least a portion of the acid in the liquid phase, converting hydrocarbon to carbon oxides and water, and converting sulfur and sulfurdioxide to sulfurtrioxide, separating the reactor effluent into a vapor stream and a liquid stream and cooling and partially condensing of the vapor stream to concentrate clean acid.
    Type: Grant
    Filed: December 14, 2005
    Date of Patent: March 18, 2008
    Assignee: Catalytic Distillation Technologies
    Inventors: Lawrence A. Smith, Jr., Abraham P. Gelbein
  • Publication number: 20080063593
    Abstract: A process for the regeneration of spent sulfuric acid comprises decomposing the spent sulfuric acid to SO2, a reducing agent, such as hydrocarbon and water, preferably in a thin film on a solid surface in the presence of a hydrocarbon reducing agent. The SO2 generated in the decomposition step is converted to SO3 in the presence of water and concentrated sulfuric acid is condensed out.
    Type: Application
    Filed: September 8, 2006
    Publication date: March 13, 2008
    Inventors: Lawrence A. Smith, Abraham P. Gelbein
  • Publication number: 20070286794
    Abstract: Process for the recovery of sulfuric acid comprising: (a) contacting a stream containing sulfuric acid vapor and/or sulfur trioxide in an absorption stage with a ionic liquid absorbent, (b) withdrawing a gas substantially free of sulfuric acid vapor and/or sulfur trioxide from said absorption stage, (c) withdrawing a stream comprising the ionic liquid absorbent from said absorption stage, in which said ionic liquid absorbent contains sulfuric acid, (d) recovering sulfuric acid from said ionic liquid absorbent by passing the stream of step (c) through a separation stage, (e) withdrawing from the separation stage (d) a stream rich in sulfuric acid, (f) withdrawing from the separating step (d) a ionic liquid absorbent stream in which said ionic liquid absorbent contains sulfuric acid and returning said stream to the absorption step (a).
    Type: Application
    Filed: June 4, 2007
    Publication date: December 13, 2007
    Inventors: Sven Ivar Hommeltoft, Morten Thellefsen
  • Patent number: 7273599
    Abstract: A method for decoloring sulfuric acid containing organic reatives by which it is possible to obtain a crystalline sulfuric acid having a color index of less that 30 APHA unities, by adding controlled amounts of potassium chlorate and hydrogen peroxide in a controlled environment.
    Type: Grant
    Filed: April 21, 2006
    Date of Patent: September 25, 2007
    Assignee: Servicios Industriales Penoles S.A. de C.V.
    Inventors: José Antonio Macias Horta, Mauro Medina Herrera, Saul Aviña Vielma, Jesús Ariel Gonzalez Ramirez
  • Patent number: 7232554
    Abstract: A process for the recovery of arsenic trioxide from acid solutions, particularly the aqueous acid effluent produced by a gas-washing process in the pyrometallurgy of copper sulfide ores is provided. Generally, the process comprises concentrating the acid solution in one or more evaporators in series; crystallizing arsenic contained in the concentrated solution as arsenic trioxide crystals; filtering the crystallized solution to obtain a solid phase comprising impure arsenic trioxide crystals; and purifying the solid phase to obtain a purified crystal product comprising arsenic trioxide. The process produces a commercially salable arsenic trioxide product without producing any solid or liquid residues subject to special handling or treatment regulations.
    Type: Grant
    Filed: December 14, 2001
    Date of Patent: June 19, 2007
    Assignee: Barrick Gold Corporation
    Inventors: Jose Mendoza Videla, Jorge Balanda Andina, Hector Gallegos Cisternas
  • Patent number: 7033565
    Abstract: A process for the production of sulphuric acid from a sulphur dioxide containing feed gas with concentration of SO2 fluctuating between 0 and 100 mole % SO2 comprising the steps of contacting the feed gas with an aqueous solution comprising 0–50% by weight H2SO4 at a temperature between the freezing point of said aqueous solution and 80° C.; and during the contact of the feed gas with the aqueous solution absorbing at least a part of SO2 in the feed gas in the aqueous solution or desorbing at least a part of SO2 from the aqueous solution, wherein the at least a part of SO2 is desorbed by stripping the aqueous solution with the feed gas and passing at least part of the thus treated feed gas to a sulphuric acid plant.
    Type: Grant
    Filed: August 6, 2004
    Date of Patent: April 25, 2006
    Assignee: Haldor Topsoe A/S
    Inventors: Kurt Agerbæk Christensen, Peter Schoubye
  • Publication number: 20040126311
    Abstract: A process for the removal of organic impurities from sulfuric acid utilizing either liquid or super critical carbon dioxide is provided. The process comprises providing a solution of sulfuric acid contaminated with at least one organic compound and subjecting the solution to countercurrent extraction with one of supercritical carbon dioxide and liquid carbon dioxide. Processes for removing organic contaminants from a waste stream generated in the manufacture of trinitrotoluene are also provided.
    Type: Application
    Filed: December 31, 2002
    Publication date: July 1, 2004
    Inventors: Andrew Sanderson, Sharon Dressen
  • Patent number: 6740302
    Abstract: The invention relates to a novel method for producing high-purity sulfuric acid for use in the semiconductor industry. The method comprises the addition of a hydrogen peroxide solution to an engineered oelum in order to reduce the SO2 concentration, evaporation of the SO3 and separation of acid traces. The high-purity SO3 is then enriched with inert gas and the SO3 is absorbed into sulfuric acid.
    Type: Grant
    Filed: June 26, 2002
    Date of Patent: May 25, 2004
    Assignee: Merck Patent GmbH
    Inventors: Martin Hostalek, Werner Büttner, Rolf Hafner, Chih-Peng Lu, Ching-Jung Kan, Ekkehart Seitz, Ernst Friedel
  • Patent number: 6649070
    Abstract: A technique of utilizing a sulfuric acid/peroxide liquid mixture, for example, its waste liquid material, is to be developed so that the waste liquid can be re-utilized and effectively applied to obviate the problem resulting from disposal. To this end, there is provided a method for utilizing a sulfuric acid/peroxide liquid mixture, for example, its waste liquid, in which peroxide in the sulfuric acid/peroxide liquid mixture is decomposed to render it possible to utilize the liquid mixture as sulfuric acid.
    Type: Grant
    Filed: December 1, 1998
    Date of Patent: November 18, 2003
    Assignee: Sony Corporation
    Inventor: Yasuhito Inagaki
  • Patent number: 6641791
    Abstract: The invention relates to the preparation of BF3 and H2SO4 of commercial grade from boron trifluoride hydrate effluents containing organic impurities. The process consists essentially in reacting the said effluent with oleum, in recovering the gaseous boron trifluoride thereby liberated and in subjecting the sulphuric acid by-product to treatment with hydrogen peroxide and to purging with air.
    Type: Grant
    Filed: December 8, 1998
    Date of Patent: November 4, 2003
    Assignee: Elf Atochem
    Inventors: Jean-Paul Chalieux, Christian Pralus
  • Patent number: 6627172
    Abstract: Process for preparing sulphuric acid from gasses containing SO3 and gaseous nitrosylsulphuric acid (NO+HSO4− or HO3SONO) by contact with 94% to 98% sulphuric acid, wherein the gases flow through at least one cooler and are cooled down to 160° C. to 130° C. to condense out nitrosylsulphuric acid before being brought into contact with the sulphuric acid.
    Type: Grant
    Filed: June 14, 1999
    Date of Patent: September 30, 2003
    Assignee: Metallgesellschaft Aktiengesellschaft
    Inventors: Hartmut Wagner, Roland Fach
  • Publication number: 20030079981
    Abstract: A distilling apparatus and method use a two step distillation and purification process for processing a waste liquid, such as an impure sulfuric acid solution, to form a highly concentrated sulfuric acid solution. First, the waste liquid is stored in a concentrating column, where it is heated. A condenser, which uses the waste liquid as a cooling medium, condenses the vapor generated by the heater. The condensed vapor is passed through a filter, which separates impurities out of the waste liquid, prior to feeding the waste liquid back into the concentrating column. Water is then removed from the waste liquid via a distilling process. The resulting concentrated liquid is then fed to a purifying column, where it is again heated, to remove residue, and condensed, resulting in a highly pure waste liquid.
    Type: Application
    Filed: November 22, 2002
    Publication date: May 1, 2003
    Applicant: FUJITSU LIMITED
    Inventors: Hiroshi Osuda, Toru Matoba, Daisuke Adachi, Masataka Fukuizumi
  • Patent number: 6548038
    Abstract: A process is provided for increasing the concentration of sulfuric acid in a waste solution of sulfuric acid previously used to produce titanium dioxide. The waste solution of sulfuric acid is fed into a first heat exchanger/evaporator stage that operates at a sulfuric acid concentration of less than 30%. A portion of the solution discharged from the first heat exchanger/evaporator is fed into a heat exchanger/evaporator that uses waste heat and operates at a sulfuric acid concentration that is greater than 40%, while the remainder of the solution discharged from the first heat exchanger/evaporator and the solution discharged from the heat exchanger/evaporator using waste heat is fed into a second heat exchanger/evaporator that operates at a sulfuric acid concentration that is greater than 50%.
    Type: Grant
    Filed: January 29, 2001
    Date of Patent: April 15, 2003
    Assignee: Tioxide Group Services Limited
    Inventor: James Henry Bush
  • Patent number: 6495024
    Abstract: The object of this invention is a method by which arsenic is removed from sulfuric acid solution, in which the sulfuric add concentration is at least 300 g/l, at a temperature of 50-105° C. by reducing the arsenic in the solution with the aid of sulfur dioxide. The arsenic trioxide produced is crystallized from the sulfuric acid solution by cooling. The method is particularly suitable for use in connection with the electrolytic refining of metals, as in copper refining.
    Type: Grant
    Filed: November 28, 2000
    Date of Patent: December 17, 2002
    Assignee: Cutokumpo OYJ
    Inventors: Leo Lindroos, Henri Virtanen
  • Publication number: 20020031469
    Abstract: Process and apparatus for regenerating spent acid liquor includes a primary roasting furnace for evaporating a substantial portion of the liquid from the spent acid to produce acid vapors and partially roasted metal salts. The partially roasted metal salts are transferred to a secondary roasting chamber where the acids adhering to the surface of the metal salts is vaporized and the metal salts are oxidized. The acid vapors from the primary roasting furnace are then transferred to an absorption column to regenerate the acid. The primary roasting furnace is operated at a different temperature from the secondary roasting chamber and has different retention times for the metal salts. The secondary roasting chamber includes a raking device to mix and convey the metal salts during the secondary roasting step to produce a uniformly roasted metal oxide.
    Type: Application
    Filed: January 8, 2001
    Publication date: March 14, 2002
    Inventor: Albert Lebl
  • Patent number: 6337061
    Abstract: For the purpose of efficiently and easily regenerating a sulfuric acid solution having a high concentration and a low impurity content from a metal sulfate-containing waste sulfuric acid solution and waste liquor formed during acid cleaning which are discharged from titanium (IV) oxide-production process carried out according to the sulfuric acid method, titanium present in the metal sulfate-containing waste sulfuric acid solution is removed through a solvent-extraction treatment and then the solution obtained after the solvent-extraction is subjected to a diffusive dialysis treatment.
    Type: Grant
    Filed: March 28, 1995
    Date of Patent: January 8, 2002
    Assignee: Nittetsu Mining Co., Ltd.
    Inventors: Nobuyoshi Iyatomi, Yasuie Mikami
  • Patent number: 6332949
    Abstract: A process for concentrating spent sulphuric acids particularly sulphuric acids which arise during the nitration of hydrocarbons with nitric acid in the presence of sulphuric acid, wherein single- or multi-stage concentration is effected under vacuum.
    Type: Grant
    Filed: March 30, 1999
    Date of Patent: December 25, 2001
    Assignee: Bayer Aktiengesellschaft
    Inventors: Heiko Beckhaus, Jürgen Münnig, Wolfgang Lorenz, Karl Schumacher
  • Patent number: 6315975
    Abstract: Fumed silica is used to suspend iron sulfates in concentrated sulfuric acid. The suspension system substantially reduces iron sulfate deposits in steel containment vessels.
    Type: Grant
    Filed: September 10, 1999
    Date of Patent: November 13, 2001
    Assignee: Rhodia Inc.
    Inventor: Donald Edward Lindblad
  • Patent number: 6238639
    Abstract: Nitrosylsulphuric acid is mixed in a mixing reactor with sulphuric acid saturated with SO2. The acid mixture is led into a saturating reactor into the bottom region of which water and an SO2-containing gas are introduced. The gas partially serves as stripping gas inside the saturating reactor. SO2-saturated, Nox-free sulphuric acid with 5 to 60 wt % H2SO4 is removed from the bottom region of the saturating reactor and part thereof is mixed with nitrosylsulphuric acid in the mixing reactor.
    Type: Grant
    Filed: May 14, 1999
    Date of Patent: May 29, 2001
    Assignee: Metallgesellschaft Aktiengesellschaft
    Inventors: Georg Schmidt, Egon Winkler, Hartmut Wagner, Ronald Apel, Roland Fach, Dieter Knoblich, Peter-Bernhard Stougie
  • Patent number: 6214304
    Abstract: A method of removing mercury from a mercury-containing flue gas, especially flue gas from a refuse incinerator, is provided. The mercury-containing flue gas may also contain dust, further heavy metals, and further gaseous noxious gas components. The mercury, using an alkali sulfide solution, especially sodium sulfide solution, and in particular sodium tetrasulfide solution, is converted to mercury sulfide and the mercury sulfide is precipitated out via a dust separator. The alkali sulfide solution is introduced into the flue gas accompanied by the simultaneous addition of heat.
    Type: Grant
    Filed: December 15, 1999
    Date of Patent: April 10, 2001
    Assignee: L & C Steinmüller GmbH
    Inventors: Jürgen Rosenthal, Wolfgang Schüttenheim, Marton Klein, Rüdiger Heidrich, Ulrich Nikolai, Uwe Soldner
  • Patent number: 6159382
    Abstract: A process for purifying a sulfuric acid solution such as by cooling a sulfuric acid solution to at or near its freezing point to form a slurry of a solid phase and a liquid phase. The slurry has an acid-rich region and an acid-poor region. The acid-rich region is separated from the acid-poor region on the basis of density.
    Type: Grant
    Filed: October 7, 1998
    Date of Patent: December 12, 2000
    Assignee: Waterworks International Inc.
    Inventors: Lawrence D. Conant, Arie Keus
  • Patent number: 6156288
    Abstract: A process is provided for the purification of sulfuric acid contaminated with impurities, such as nitric acid, nitrosylsulfuric acid, dinitrotoluenes and mononitrotoluenes, wherein this contaminated sulfuric acid was obtained from the production of nitrated toluene using toluene and nitric acid. The contaminated sulfuric acid is preheated to a temperature in the range of 50 to 180.degree. C. in a heat exchanger. The heated, contaminated sulfuric acid is freed from steam-volatile impurities, such as dinitrotoluenes and mononitrotoluenes, and the nitrogen-containing compounds within the sulfuric acid are decomposed by counter currently contacting the contaminated sulfuric acid with steam and vapors from a downstream concentration step in a steam stripper, which is operated at a pressure ranging from 300 to 1,000 mbars. The steam-stripped sulfuric acid is fed into a first concentration stage, which is operated at the same pressure used in the steam stripper.
    Type: Grant
    Filed: December 4, 1998
    Date of Patent: December 5, 2000
    Assignee: Bayer Aktiengesellschaft
    Inventors: Heiko Beckhaus, Jurgen Munnig, Dieter Grenner