Using Bipolar Membrane Patents (Class 204/537)
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Publication number: 20020005356Abstract: Bipolar membrane electrodialysis methods for salt splitting polyvalent metal salts, where the metal cation can form substantially insoluble precipitates in the presence of hydroxyl ions can now be used in recovering acid and base values from a salt streams without precipitates fouling cell operation and causing shutdown. The introduction of an acid to the chamber where metal hydroxides would form inhibits their development or neutralizes formed solids, allowing salt splitting to continue. Salt splitting methods of the invention performed with a three compartment bipolar electrodialysis cell are useful in producing concentrated and purified acid forms, such as 2-keto-L-gluconic acid, H(KLG), a key intermediate in the production of ascorbic acid.Type: ApplicationFiled: July 9, 2001Publication date: January 17, 2002Inventors: Duane J. Mazur, J. David Genders, Dan M. Hartsough
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Patent number: 6319382Abstract: A method for fermentation of lactic acid from a sugar-containing fermentation liquid in a fermentor by means of lactic acid-forming bacteria, in which whey protein is present or is added as a nutrient substrate for the lactic acid-forming bacteria, wherein at least one protease is added to the fermentor during the fermentation, so that hydrolysis of protein to amino acids takes place simultaneously with the fermentation of sugar into organic acid, and wherein lactic acid resulting from the fermentation is isolated from the fermentation liquid. Ammonia is preferably added to result in the formation of ammonium lactate, and lactic acid is preferably isolated by a process comprising ultra filtration, ion exchange, conventional electrodialysis and electrodialysis with bipolar membranes.Type: GrantFiled: August 11, 1999Date of Patent: November 20, 2001Assignee: Lactascan ApSInventor: Birgir Norddahl
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Publication number: 20010040093Abstract: An apparatus and process produces salts by an electrodialysis operation. The basic electrodialysis apparatus is a cell having a number of compartments separated by membranes. A DC source is connected to drive a current through a feed stream passing through the cell which splits the salt stream into an acid and a base. The incoming feed may be nanofiltered to remove divalent metal. The base loop may be in communication with an ion exchange column packed with a material that removes multivalent cations. Depending upon the material being processed and the desired end result either or both the nanofiltration and the ion exchanged column may be used in the apparatus.Type: ApplicationFiled: February 14, 2001Publication date: November 15, 2001Applicant: Archer Daniels Midland CompanyInventor: K. N. Mani
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Patent number: 6294066Abstract: An apparatus and the process produces salts by an electrodialysis operation. The basic electrodialysis apparatus is a cell having a number of compartments separated by membranes. A DC source is connected to drive a current through a feed stream passing through the cell which splits the salt stream into an acid and a base. The incoming feed may be nanofiltered to remove divalent metal. The base loop may be in communication with an ion exchange column packed with a material that removes multivalent cations. Depending upon the material being processed and the desired end result either or both the nanofiltration and the ion exchanged column may be used in the apparatus.Type: GrantFiled: January 23, 1997Date of Patent: September 25, 2001Assignee: Archer Daniels Midland CompanyInventor: K. N. Mani
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Patent number: 6217733Abstract: A bipolar membrane, usable for electrodialysis of aqueous electrolytes, comprises two ion exchange membranes, respectively anionic and cationic, juxtaposed along a common surface, wherein, along said common surface, a gel based on hydrated metal sulpate and/or sulphite, including less than 0.01 mol % of indium, cerium, manganese and copper sulphates gel, is formed.Type: GrantFiled: May 5, 1997Date of Patent: April 17, 2001Assignees: Solvay (Societe Anonyme), Electricite de FranceInventors: Heinz Hurwitz, Rachid El Moussaoui
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Patent number: 6217743Abstract: In one embodiment, the present invention relates to a process for recovering an onium compound from waste solutions or synthetic solutions containing the onium compound and impurities including the steps: contacting the waste solution or synthetic solution with a metal ion scavenger to remove metal ion impurities, wherein the metal ion scavenger comprises at least one of a chelating compound, a nanoporous material, and a magnetically assisted (MACS) material; charging the waste solution or synthetic solution to an electrochemical cell containing at least two compartments, a cathode, an anode and a divider and passing a current through the cell whereby the onium compound is regenerated or produced; and recovering the onium compound from the cell.Type: GrantFiled: August 9, 1999Date of Patent: April 17, 2001Assignee: Sachem, Inc.Inventors: Roger D. Moulton, Weilian Lang, Allen Tanner
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Patent number: 6187570Abstract: A process for purifying and concentrating a gluconic acid derivative, such as 2-keto-L-gulonic acid, comprising introducing a non-viable and/or acidified fermentation medium or an in-vitro reactor medium comprising at least the gluconic acid derivative and/or salt thereof to electrodialysis thereby purifying and concentrating the gluconic acid derivative.Type: GrantFiled: May 25, 1999Date of Patent: February 13, 2001Assignee: The Electrosynthesis Company, Inc.Inventors: J. David Genders, Ram Gopal, Dan M. Hartsough, Peter M. Kendall, William J. Long, Duane J. Mazur, Guillermo D. Zappi
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Patent number: 6110342Abstract: The invention uses a stack of three compartment electrodialysis cells in a process for the production amino acid hydrochloride and an alkali. The electrodialysis cell contains bipolar, cation and anion membranes which are arranged to form acid, base and salt compartments. The process begins with supplying a salt solution to the salt compartment, water to the base compartment, and a liquid comprising an amino acid to the acid compartment. Preferably, the feed salt is sodium chloride or potassium chloride or lithium chloride. A direct current driving force is applied across the cell to convert the salt solution to an alkali in the base compartments and an amino acid hydrochloride in the acid compartment. The acid and alkali solutions and a depleted salt solution are withdrawn from their respective compartments. A chelating agent may be added to the salt solution before it is fed into the electrodialysis cell.Type: GrantFiled: December 30, 1998Date of Patent: August 29, 2000Assignee: Archer Daniels Midland CompanyInventor: K. N. Mani
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Patent number: 6024855Abstract: In one embodiment, the present invention relates to a method of preparing a hydroxylammonium salt, involving the steps of: providing an electrochemical cell containing an anode, a cathode, and a divider positioned between the anode and the cathode, to define a catholyte compartment between the cathode and the divider and an anolyte compartment between the anode and the divider; charging the catholyte compartment with a first solution comprising a nitrogen containing compound and a mediator and the anolyte compartment with a second solution comprising an ionic compound; passing a current through the electrochemical cell to produce a hydroxylammonium salt in the catholyte compartment; and recovering the hydroxylammonium salt from the catholyte compartment.Type: GrantFiled: August 13, 1998Date of Patent: February 15, 2000Assignee: Sachem, Inc.Inventors: Hossein Sharifian, John H. Wagonknecht
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Patent number: 6004445Abstract: The present invention relates to electrochemical methods for the recovery of ascorbic acid from an ascorbate salt without the co-generation of a waste salt stream and while maintaining high conductivity of the electrochemical cell thereby providing for quantitative conversion of the salts to ascorbic in both batch and continuous mode processes. In one embodiment the feed stream comprising an ascorbate salt is dissociated under the influence of an electric field and subjected to water splitting electrodialysis. The ascorbate ion combines with a proton and the salt cation combines with a hydroxyl ion to form ascorbic acid and base, respectively. The feed stream further comprises an inorganic salt which maintains high conductivity in the cell, facilitates quantitative conversion of ascorbate salts to ascorbic acid in both batch and continuous mode processes, and promotes precipitation and crystallization of ascorbic acid as a fine powder.Type: GrantFiled: June 30, 1998Date of Patent: December 21, 1999Assignee: Electrosynthesis Company, Inc.Inventors: J. David Genders, Dan M. Hartsough
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Patent number: 5993629Abstract: An electrodialysis method using a bipolar membrane (BP) for regenerating acids, wherein a series of base (B), acid (A) and salt (S) compartments are provided between a positive electrode (anode) and a negative electrode (cathode), said compartments being defined by a series of membranes: cationic, bipolar, anionic, cationic, bipolar and so forth, and a solution being circulated through each compartment. An additional anionic membrane (10) is applied to the anionic side (11) of the bipolar membrane (BP) with no discernible gap therebetween so that contamination of the acid compartment by cations is reduced.Type: GrantFiled: July 17, 1997Date of Patent: November 30, 1999Assignee: Elf Atochem S.A.Inventors: Claude Gavach, Christian Gancet, Alfred Mirassou, Frederic Perie
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Patent number: 5980724Abstract: Described is a method of electrochemically converting .alpha.-halohydrins, e.g., 1-chloro-2-hydroxypropane and 1,3-dichloro-2-hydroxypropane, to epoxides, e.g., propylene oxide and epichlorohydrin. An electrolytic cell is provided having (1) a catholyte compartment containing a cathode assembly comprising a cathode and a bipolar ion exchange membrane, (2) an anode compartment containing an anode assembly comprising either (a) a hydrogen consuming gas diffusion anode and a current collecting electrode or (b) a hydrogen consuming gas diffusion anode which is fixedly held between a hydraulic barrier and a current collecting electrode, and (3) at least one pair of intermediate compartments separating the catholyte and anode compartments and separated from each other by an anion exchange membrane. The following are introduced into the cell: a first aqueous conductive electrolyte solution into the catholyte compartment; hydrogen gas into the anode compartment; an aqueous solution of .alpha.Type: GrantFiled: July 9, 1998Date of Patent: November 9, 1999Assignee: PPG Industries Ohio, Inc.Inventors: David G. Roberts, Peter C. Foller, Robert H. Tang, Yingchao Zhang
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Patent number: 5968338Abstract: In one embodiment, the present invention relates to a process for recovering an onium hydroxide from a solution containing an onium compound, including contacting the solution with a cation exchange material so that at least a portion of onium cations from the onium compound are adsorbed by the cation exchange material; contacting an acid with the cation exchange material to elute an onium salt; charging the onium salt to an electrochemical cell containing at least three compartments, a cathode, an anode, and in order from the anode to the cathode, a bipolar membrane and a cation selective membrane, and passing a current through the cell whereby the onium hydroxide is regenerated; and recovering the onium hydroxide from the cell.Type: GrantFiled: January 20, 1998Date of Patent: October 19, 1999Assignee: Sachem, Inc.Inventors: David R. Hulme, Roger Moulton, Wilfred W. Wilson, Mark Hellums
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Patent number: 5951845Abstract: In one embodiment, the present invention relates to a process for recovering an organic hydroxide from waste solutions containing the organic hydroxide and impurities including the steps: contacting the waste solution with a metal ion scavenger to remove metal ion impurities; charging the waste solution to an electrochemical cell containing at least two compartments, a cathode, an anode and a divider and passing a current through the cell whereby the organic hydroxide is regenerated; and recovering the organic hydroxide from the cell.Type: GrantFiled: March 4, 1997Date of Patent: September 14, 1999Assignee: Sachem, Inc.Inventor: Roger D. Moulton
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Patent number: 5910237Abstract: In one embodiment, the present invention relates to a process for recovering organic hydroxide from contaminated solutions containing the organic hydroxide and impurities including charging the contaminated solution to a first electrochemical cell containing at least two compartments, a cathode, an anode and a size selective divider and passing a current through the first electrochemical cell whereby impurities migrate through the size selective divider; recovering a second solution containing organic ions from the first electrochemical cell and charging the second solution to a second electrochemical cell containing at least two compartments, a cathode, an anode and a divider and passing a current through the second electrochemical cell whereby the organic hydroxide is purified; and recovering the organic hydroxide from the second electrochemical cell.Type: GrantFiled: March 11, 1997Date of Patent: June 8, 1999Assignee: Sachem, Inc.Inventors: Roger D. Moulton, Mark W. Hellums
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Patent number: 5904829Abstract: Describes a method of electreochemically converting amine hydrohalide, e.g., amine hydrochloride, into free amine, e.g., free ethyleneamine. An electrolytic cell is provided having (1) a catholyte compartment containing a cathode assembly comprising a cathode and a bipolar ion exchange membrane, (2) an anode compartment containing an anode assembly comprising either (a) a hydrogen consuming gas diffusion anode and a current collecting electrode or (b) a hydrogen consuming gas diffusion anode which is fixedly held between a hydraulic barrier and a current collecting electrode, and (3) at least one pair of intermediate compartments separating the catholyte and anode compartments and separated from each other by an anion exchange membrane.Type: GrantFiled: August 18, 1997Date of Patent: May 18, 1999Assignee: PPG Industries, Inc.Inventors: Peter C. Foller, David G. Roberts, Robert H. Tang
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Patent number: 5904823Abstract: In one embodiment, the present invention provides a method of preparing hydroxylamine from a hydroxylammonium salt solution, including providing an electrochemical cell containing an anode, a cathode, a cation selective membrane and an anion selective membrane, wherein the cation selective membrane is positioned between the cathode and the anion selective membrane, and the anion selective membrane is positioned between the cation selective membrane and the anode, thereby defining a feed compartment between the cation selective membrane and the anion selective membrane, a recovery compartment between the cathode and the cation selective membrane, and an acid compartment between the anion selective membrane and the anode; charging a first solution to the acid compartment and a second solution the recovery compartment; charging the hydroxylammonium salt solution to the feed compartment; passing a current through the cell to produce hydroxylamine in the recovery compartment; and recovering hydroxylamine from theType: GrantFiled: April 10, 1997Date of Patent: May 18, 1999Assignee: Sachem, Inc.Inventors: Hossein Sharifian, Christopher D. Shay
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Patent number: 5888368Abstract: Process for manufacturing sodium hydroxide by the electrodialysis of sodium carbonate in an electrodialysis cell having three compartments, in which an aqueous sodium carbonate solution is introduced into a compartment of the cell which is bounded between two cationic membranes, an acid is introduced into a compartment which is bounded between one of the cationic membranes and a cationic face of a bipolar membrane, and an aqueous sodium hydroxide solution is removed from a compartment which is adjacent to an anionic face of the bipolar membrane.Type: GrantFiled: October 29, 1997Date of Patent: March 30, 1999Assignee: Solvay (Societe Anonyme)Inventor: Francesco Posar
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Patent number: 5876579Abstract: A process for reducing the content of organic and inorganic halogen in an aqueous solution of a nitrogen-containing epihalohydrin-based resin, in which process the aqueous resin solution is subjected to an electrodialysis treatment. The aqueous resin solutions obtained by the process are used as additives in the production of paper, board and paper board, in particular as wet-strength agents.Type: GrantFiled: April 2, 1997Date of Patent: March 2, 1999Assignee: Eka Chemicals ABInventor: Marek Gorzynski
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Patent number: 5853555Abstract: The present invention provides a process for preparing onium hydroxide from a corresponding onium salt and for purifying onium hydroxide including providing an electrochemical cell containing a cathode, an anode, a divider and a bipolar membrane, the bipolar membrane having an anion selective side facing the anode and a cation selective side facing the cathode, wherein the divider is positioned between the cathode and the bipolar membrane, and the bipolar membrane is positioned between the divider and the anode, thereby defining a feed compartment between the divider and the bipolar membrane, a recovery compartment between the divider and the cathode, and a water compartment between the bipolar membrane and the anode; charging a solution containing at least one of the onium salt and the onium hydroxide to be purified to the feed compartment; charging a liquid electrolyte to the other compartments; passing a current through the electrochemical cell to produce the onium hydroxide in the recovery compartment; anType: GrantFiled: April 3, 1997Date of Patent: December 29, 1998Assignee: Sachem, Inc.Inventors: Hossein Sharifian, David R. Hulme
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Patent number: 5849167Abstract: Process for the manufacture of a bipolar membrane, according to which an anionic membrane is joined side by side to a cationic membrane, the membranes having been subjected beforehand to a conditioning pretreatment, the conditioning pretreatment of the anionic membrane comprising bringing the latter into contact with a compound of a polyvalent metal and with an aqueous alkali metal hydroxide solution and the conditioning pretreatment of the cationic membrane essentially comprising bringing the said cationic membrane into contact with water which is essentially free from polyvalent metal and from alkali metal. Use of the bipolar membrane thus obtained for the manufacture of aqueous sodium hydroxide solutions by electrodialysis.Type: GrantFiled: June 10, 1997Date of Patent: December 15, 1998Assignee: SOLVAY (Societe AnonymeInventor: Francesco Posar
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Patent number: 5833832Abstract: A process is described for preparing onium hydroxides from the respective onium salts and for purifying onium hydroxides in an electrochemical cell. In one example, the present invention relates to a process for preparing onium hydroxides from the corresponding onium salts which comprises the steps of: (A) providing a cell comprising an anode, a cathode and one or more unit cells assembled for operational positioning between the anode and the cathode, each unit cell comprising: (A-1) four compartments defined by, in sequence beginning at the anode, a bipolar membrane, a first divider and a second divider, said bipolar membrane having an anion selective side facing the anode and a cation selective side facing the cathode.Type: GrantFiled: August 30, 1996Date of Patent: November 10, 1998Assignee: Sachem, Inc.Inventors: Christopher D. Shay, Hossein Sharifian
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Patent number: 5814498Abstract: A process recovers organic acid and ammonia from their salts preferably obtained from microbial fermentation of a saccharide in a nutrient. The fermented materials is passed through a nanofiltration or a chelating resin ion-exchange bed or a combination of both a nanofilter and a chelating resin ion-exchange bed in order to reduce divalent or multivalent metal contaminants. Then, the filtered material is processed in a multi compartment electrodialysis containing bipolar and anion membranes.Type: GrantFiled: April 29, 1996Date of Patent: September 29, 1998Assignee: Archer Daniels Midland CompanyInventors: K. N. Mani, D. Kent Hadden
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Patent number: 5788826Abstract: A electrochemical cell for removing ions from a solution stream comprises a housing having first and second electrodes. At least one water-splitting ion exchange membrane is positioned between the electrodes, the water-splitting membrane comprising (i) a cation exchange surface facing the first electrode, and (ii) an anion exchange surface facing the second electrode. A solution stream pathway is defined by the water-splitting membrane. The solution stream pathway comprises (i) an inlet for influent solution stream, (ii) at least one channel that allows influent solution stream to flow past at least one surface of the water-splitting membrane to form one or more treated solution streams, and (iii) a single outlet that combines the treated solution streams to form a single effluent solution.Type: GrantFiled: January 28, 1997Date of Patent: August 4, 1998Assignee: Pionetics CorporationInventor: Eric D. Nyberg
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Patent number: 5772013Abstract: A method is disclosed for producing di- and more highly oxidized carboxylic acids from a compound selected from a first group consisting of carbohydrates, carbohydrate derivatives and carbohydrate derivatives having more than one primary alcohol group, comprising oxidizing, in an aqueous solution in a concentration between 0.1% and 60%, the compound selected from said first group and a compound selected from a second group consisting of monooxidized carbohydrates, monooxidized carbohydrate derivatives and monooxidized carbohydrate derivatives having more than one primary alcohol group, with one of oxygen and an oxygen-containing gas, on one of a noble metal catalyst and a mixed metal catalyst; electrodialyzing the oxidized compounds in at least one electrodialysis stage; and removing said di- and more highly oxidized carboxylic acids in said at least one electrodialysis stage.Type: GrantFiled: November 14, 1996Date of Patent: June 30, 1998Assignee: Sudzucker Akiengesellschaft Mannheim/OchsenfurtInventors: Markwart Kunz, Andreas Schwarz, Jorg Kowalczyk
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Patent number: 5766439Abstract: A process is described for producing organic acids such as lactic acid. The process includes the steps of producing lactic acid by fermentation, resulting in an aqueous fermentation broth containing lactic acid, and adding a calcium base, such as calcium carbonate, to the fermentation broth, thereby producing calcium lactate in the broth. Biomass is removed from the broth, thereby leaving an aqueous solution or dispersion of calcium lactate. The calcium lactate is reacted with a source of ammonium ions, such as ammonium carbonate, or a mixture of ammonia and carbon dioxide, thereby producing an ammonium lactate. Contaminating cations can be removed by ion exchange. The free lactic acid or a derivative thereof can be separated from the ammonium ions, preferably by salt-splitting electrodialysis.Type: GrantFiled: November 20, 1996Date of Patent: June 16, 1998Assignee: A. E. Staley Manufacturing Co.Inventors: Aharon M. Eyal, William F. Lehnhardt
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Patent number: 5753097Abstract: In one embodiment, the invention relates to a process for purifying solutions containing a hydroxide compound, including the steps of: (A) providing an electrochemical cell containing an anode, a cathode, a cation selective membrane and a bipolar membrane, the bipolar membrane having an anion selective side facing the anode and a cation selective side facing the cathode, wherein the cation selective membrane is positioned between the anode and the bipolar membrane, and the bipolar membrane is positioned between the cation selective membrane and the cathode, thereby defining a feed compartment between the cation selective membrane and the anode, a recovery compartment between the bipolar membrane and the cation selective membrane, and a water compartment between the bipolar membrane and the cathode; (B) charging a solution of an ionic compound at a first concentration to the water compartment, and water to the recovery compartment; (C) charging a solution containing the hydroxide compound at a second concentraType: GrantFiled: October 3, 1996Date of Patent: May 19, 1998Assignee: Sachem, Inc.Inventors: Hossein Sharifian, John E. Mooney
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Patent number: 5746920Abstract: A process and apparatus for purifying lactose-containing wastewater. The process comprises first treating the wastewater with base. The treated wastewater is then introduced into a fermenter where the lactose present in the wastewater is fermented to form a fermentation broth and lactic acid. The broth is advantageously subjected to purification and the purified broth is subjected to bipolar electrodialysis to yield concentrated lactic acid and base solutions from the purified broth. A device is provided for carrying out the process.Type: GrantFiled: February 8, 1996Date of Patent: May 5, 1998Assignee: Fraunhofer-Gesellschaft zur Foerder der Angewandten Forschung e.V.Inventors: Peter Boergardts, Wolfgang Krischke, Walter Troesch
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Patent number: 5725749Abstract: The invention relates to a process for the separation of lactulose from a mixture of lactulose and lactose in the presence of a weak acid capable of reversibly forming a complex with lactulose, by using an electrodialysis equipment including an anode and a cathode compartment separated by a plurality of parallel compartments comprising alternating diluate and concentrate compartments, wherein adjacent compartments are separated from each other by permselective membranes; which process is characterized by:(a) continuously passing an alkaline aqueous solution of lactulose, lactose and said complex forming weak acid through the diluate compartments, each diluate compartment being bound by a bipolar membrane at its lateral side facing the cathode and at its opposite lateral side by an anion exchange membrane, separating said compartment from its adjacent concentrate compartment;(b) continuously passing a carrier fluid through the concentrate compartments, each concentrate compartment being bound at its lateral siType: GrantFiled: October 29, 1996Date of Patent: March 10, 1998Assignee: Duphar International Research B.V.Inventor: Hendrik Pluim
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Patent number: 5720865Abstract: Keto compounds are prepared by a condensation reaction in which an enolate is formed, and then a protonation in which the free keto compound is produced. In accordance with the invention, both condensation and protonation are carried out in one step by electrodialysis. Transesterification can also be carried out in the same step.Type: GrantFiled: November 30, 1995Date of Patent: February 24, 1998Assignee: Huels AktiengesellschaftInventor: Srinivasan Sridhar
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Patent number: 5709789Abstract: The present invention relates to a method of preparing hydroxylamine in an electrochemical cell, comprising the steps of: providing an electrochemical cell comprising an anode, a cathode, a bipolar membrane positioned between the anode and the cathode, the bipolar membrane having an anion selective side facing the anode and a cation selective side facing the cathode, and a divider positioned between the bipolar membrane and the anode, thereby defining a feed compartment on the cation selective side of the bipolar membrane, a recovery compartment on the anion selective side of the bipolar membrane, and an anolyte compartment between the divider and the anode; charging the feed compartment with an acidic electrolyte and the recovery and anolyte compartments with a solution; introducing nitrogen containing gas into the feed compartment; passing a current through the electrochemical cell thereby producing hydroxylammonium salt in the feed compartment; transferring at least a portion of the hydroxylammonium salt fType: GrantFiled: October 23, 1996Date of Patent: January 20, 1998Assignee: Sachem, Inc.Inventors: Christopher D. Shay, Hossein Sharifian
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Patent number: 5709790Abstract: In one embodiment, the invention relates to a process for purifying solutions containing a hydroxide compound, including the steps of: (A) providing an electrochemical cell containing an anode, a cathode, a cation selective membrane and an anion selective membrane, wherein the cation selective membrane is positioned between the cathode and the anion selective membrane, and the anion selective membrane is positioned between the cation selective membrane and the anode, thereby defining a feed compartment between the cation selective membrane and the anion selective membrane, a recovery compartment between the cathode and the cation selective membrane, and a water compartment between the anion selective membrane and the anode; (B) charging a solution of an ionic compound at a first concentration to the water compartment, and water to the recovery compartment; (C) charging a solution of the hydroxide compound at a second concentration to the feed compartment; (D) passing a current through the cell to produce theType: GrantFiled: October 3, 1996Date of Patent: January 20, 1998Assignee: Sachem, Inc.Inventors: Hossein Sharifian, John E. Mooney
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Patent number: 5702579Abstract: A process for the preparation of ascorbic acid starting from an ascorbate is characterized in that an ascorbate, e.g. sodium ascorbate, dissolved in water is decomposed under the influence of an electric field by means of ion-selective membranes into ascorbate ions and cations and the latter are separated spatially from one another and then, as a result of simultaneous generation of protons and hydroxide ions, the ascorbic acid is prepared from the liberated ascorbate ions and protons and, spatially separated therefrom, the corresponding hydroxide, e.g. sodium hydroxide, is also prepared from the cations and hydroxide ions.Type: GrantFiled: December 13, 1996Date of Patent: December 30, 1997Assignee: Roche Vitamins Inc.Inventor: Joachim Veits
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Patent number: 5681728Abstract: The present invention relates to methods and apparatus for reducing the fouling of ion-selective membranes used in the electrodialytic purification of organic acids. More particularly, the present invention relates to the use of nanofiltration and chelating agents for removal of impurities from an organic acid-containing feed material to reduce the fouling of ion-selective membranes used in electrodialysis.Type: GrantFiled: June 7, 1995Date of Patent: October 28, 1997Assignee: Chronopol, Inc.Inventor: Fudu Miao
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Patent number: 5645703Abstract: A method for recovering salt from a process stream containing organic contaminants is provided, comprising directing the waste stream to a desalting electrodialysis unit so as to create a concentrated and purified salt permeate and an organic contaminants containing stream, and contacting said concentrated salt permeate to a water-splitting electrodialysis unit so as to convert the salt to its corresponding base and acid.Type: GrantFiled: December 20, 1995Date of Patent: July 8, 1997Assignee: University of ChicagoInventor: Shih-Perng Tsai
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Patent number: 5643430Abstract: A process for reducing the content of organic and inorganic halogen in an aqueous solution of a nitrogen-containing epihalohydrin-based resin, in which process the aqueous resin solution is subjected to an electrodialysis treatment. The aqueous resin solutions obtained by the process are used as additives in the production of paper, board and paper board, in particular as wet-strength agents.Type: GrantFiled: February 3, 1995Date of Patent: July 1, 1997Assignee: Eka Nobel ABInventor: Marek Gorzynski
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Patent number: 5626733Abstract: A process for the preparation of keto compounds from the associated alkali metal salts, in which process protonation is carried out by electrodialysis in a nonaqueous medium without the addition of acid which is foreign to the system, and the keto compounds are thereby liberated.Type: GrantFiled: September 22, 1995Date of Patent: May 6, 1997Assignee: Huels AktienegsellschaftInventor: Srinivasan Sridhar
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Patent number: 5567293Abstract: A process for the recovery of alkali metal hydroxide and acid from the alkali metal salts of monovalent anions which are mixed with the alkali metal salts of multivalent anions employs a water-splitting system composed of bipolar membranes in conjunction with ion-selective membranes; a two-compartment cell employs monovalent anion-selective membranes to define salt/base and acid compartments with the bipolar membranes, and a three-compartment cell employs, monovalent anion-selective and cation-selective membranes to define with the bipolar membranes, acid, salt and base compartments; the process has particular applicability to the conversion of the sodium/potassium chloride portion of the Electrostatic Precipitator (ESP) Catch of the recovery boiler of coastal and/or closed-cycle kraft pulp mills, a mixture of mostly sodium/potassium sulphate and chloride, into sodium/potassium hydroxide and hydrochloric acid; the remaining sodium/potassium sulphate solution, depleted in chloride, can thus be used as sodium/sType: GrantFiled: December 22, 1994Date of Patent: October 22, 1996Assignee: Pulp and Paper Research Institute of CanadaInventors: Michael Paleologou, Richard M. Berry, Rokhsareh Thompson, James T. Wearing