Olin Corporation

Budd L Duncan

David W Cawlfield

Kenneth E Woodard, Jr

Jerry J Kaczur

Sudhir K Mendiratta

Ronald L Dotson

Richard C Ness

Walter J Sakowski

Larry D Carpenter

Leslie R Osborne

Donald R Leonard

Jerry J Kazcur

Robert J Raynor

Richard W Ralston, Jr

Steven A Iacoviello

Ian L Madden

Manohar C Bajaj

William O Flowers

William T Wooden

The novel process of the invention produces chlorine dioxide by feeding an aqueous solution of chloric acid to a chlorine dioxide generator. The aqueous solution of chloric acid is reacted with a reducing agent in the chlorine dioxide generator to produce chlorine dioxide and a spent chloric acid solution containing metallic impurities. A portion of the spent chloric acid solution containing metallic impurities is reacted with a basic compound selected from the group consisting of alkali metal hydroxides, and alkali metal carbonates in a neutralizing zone to form a precipitate of the metallic impurities and an alkali metal chlorate solution. The precipitate of the metallic impurities is separated from the alkali metal chlorate solution and the alkali metal chlorate solution fed to an ion exchange compartment of an electrolytic cell having an anode compartment, a cathode compartment, and at least one ion exchange compartment between the anode compartment and the cathode compartment. Electrolysis of an anolyte in the anode compartment generates hydrogen ions which pass through a cation exchange membrane into the ion exchange compartment to displace alkali metal ions and produce an aqueous solution of chloric acid and alkali metal chlorate. The aqueous solution of chloric acid and alkali metal chlorate is returned to the chlorine dioxide generator. The process of the invention produces chlorine dioxide free of chlorine from mixtures of oxy-chlorine species. A continuous removal of metallic impurities permits avoiding or significantly increasing the time period between generator shutdowns.

Effluent treatment in a process for producing chlorine dioxide from

An aqueous solution of chloric acid and alkali metal chlorate is produced in an electrolytic cell having an anode compartment, a cathode compartment, and at least one ion exchange compartment between the anode compartment and the cathode compartment. The process comprises feeding an aqueous solution of an alkali metal chlorate to the ion exchange compartment, electrolyzing an anolyte in the anode compartment to generate hydrogen ions, passing the hydrogen ions from the anode compartment through a cation exchange membrane into the ion exchange compartment to displace alkali metal ions and produce an aqueous solution of chloric acid and alkali metal chlorate, passing alkali metal ions from the ion exchange compartment into the cathode compartment, removing the aqueous solution of chloric acid and alkali metal chlorate from the ion exchange compartment, and, increasing the chlorate ion concentration to provide the aqueous solution of chloric acid and alkali metal chlorate with a total chlorate ion to water molar ratio of about 0.15 or greater.

Chloric acid - alkali metal chlorate mixtures and chlorine dioxide

A process for removing NO.sub.x oxides and SO.sub.x oxides from gaseous streams contacts the gaseous stream with an aqueous solution of chloric acid. The process of the invention removes sulfur oxides and nitrogen oxides from waste gas streams without producing inorganic salts. In addition, the use of chloric acid provides improved oxidation of NO and SO.sub.2. The process can be operated to treat 'dirty' gas streams containing particulates and compounds which may poison or contaminate NO.sub.x removal systems employing catalysts.

Process for removal of NO.sub.x and SO.sub.x oxides from waste gases

An aqueous solution of chloric acid and alkali metal chlorate is produced in an electrolytic cell having an anode compartment, a cathode compartment, and at least one ion exchange compartment between the anode compartment and the cathode compartment. The process comprises feeding an aqueous solution of an alkali metal chlorate to the ion exchange compartment, electrolyzing an anolyte in the anode compartment to generate hydrogen ions, passing the hydrogen ions from the anode compartment through a cation exchange membrane into the ion exchange compartment to displace alkali metal ions and produce an aqueous solution of chloric acid and alkali metal chlorate, passing alkali metal ions from the ion exchange compartment into the cathode compartment, removing the aqueous solution of chloric acid and alkali metal chlorate from the ion exchange compartment, and reacting the aqueous solution of chloric acid and alkali metal chlorate with a strong acid having a dissociation constant of 1.times.10.sup.-4 or greater and a reducing agent to generate chlorine dioxide gas.

Electrochemical process for generating chlorine dioxide using chloric

An aqueous solution of chloric acid and alkali metal chlorate is produced in an electrolytic cell having an anode compartment, a cathode compartment, and at least one ion exchange compartment between the anode compartment and the cathode compartment. The process comprises feeding an aqueous solution of an alkali metal chlorate to the ion exchange compartment, electrolyzing an anolyte in the anode compartment to generate hydrogen ions, passing the hydrogen ions from the anode compartment through a cation exchange membrane into the ion exchange compartment to displace alkali metal ions and produce an aqueous solution of chloric acid and alkali metal chlorate, passing alkali metal ions from the ion exchange compartment into the cathode compartment, removing the aqueous solution of chloric acid and alkali metal chlorate from the ion exchange compartment, and, increasing the concentration of chloric acid in the aqueous solution of chloric acid which is substantially free of anionic and cationic impurities to to provide a chloric acid concentration of 1.0 normal or greater.

Chloric acid-alkali metal chlorate mixtures for chlorine dioxide

A process for producing chlorine dioxide from an aqueous solution of chloric acid and alkali metal chlorate which is prouced in a electrolytic cell having an anode compartment, a cathode compartment and at least one ion exchange compartment between the anode and cathode compartments. The process includes the steps of feeding an aqueous solution of an alkali metal chlorate to the ion exchange compartment, electrolyzing an anolyte in the anode compartment to generate hydrogen ions, passing the hydrogen ions from the anode compartment through a cation exchange membrane into the ion exchange compartment to displace alkali metal ions and produce an aqueous solution of chloric acid and alkalimetal chlorate, passing the alkali metal ions from the ion exchange compartment into the cathode compartment, and finally passing the aqueous solution of chloric acid and alkali metal chlorate to a chlorate dioxide generator.

Electrochemical process for producing chloric acid-alkali metal chlorate

A process for producing sodium hypochlorite slurries admixes a hypochlorous acid solution having a concentration of 35 percent or greater by weight of HOCl with sodium hydroxide at a temperature below about 25.degree. C. The reaction produces a slurry of sodium hypochlorite pentahydrate in an aqueous solution of sodium hypochlorite where the sodium hypochlorite is present in a concentration of at least 35 percent by weight of NaOCl. The sodium hypochlorite slurries have improved stability and greatly reduced amounts of sodium chloride. The process for produces high strength sodium hypochlorite compositions of high purity having improved yields and reduced product decomposition.

Process for the production of highly pure concentrated slurries of

An electrolytic filter press membrane cell and a method of operating the cell to produce concentrated perchloric acid are disclosed. The cell employs concentrated hypochlorous acid as the anolyte and operates with a two-stage single oxidation process at high current density.

Process for the production of perchloric acid

A process for producing dichlorine monoxide which includes: feeding an aqueous solution of hypochlorous acid containing at least 20% by weight of HOCl to a reaction vessel; maintaining the temperature of the aqueous solution of hypochlorous acid in the range of from about -10.degree. to about +40.degree. C.; passing an inert gas through the aqueous solution of hypochlorous acid to produce a gaseous mixture comprising dichlorine monoxide, chlorine and inert gas; an contacting the gaseous mixture with dry ice to provide a solid phase of dry ice and dichlorine monoxide.

Recovery of dichlorine monoxide from hypochlorous acid solutions

A process for treating wastewater the improvement which comprises admixing with the wastewater at least 0.5 percent by weight of a solution consisting of hypochlorous acid having a pH of less than 3 to prepare disinfected wastewater having substantially no available chlorine residual. The novel process of the present invention provides rapid, intimate mixing of the highly pure, highly acidic hypochlorous acid solution with the wastewater stream to disinfect wastewater bodies while minimizing unwanted side effects. The process eliminates the need for storing and handling pressurized gaseous or liquid chlorine.

Process for purifying wastewater with hypochlorous acid

A process for sanitizing impotable water the improvement which comprises admixing with the impotable water a solution consisting of hypochlorous acid containing at least 0.5 percent by weight of HOCl and having a pH of less than 3 to prepare potable water having an available chlorine residual.

Process for purifying impotable water with hypochlorous acid

A process for producing chloric acid in an electrolytic cell having an anode and a cathode which includes feeding an aqueous solution of hypochlorous acid to the electrolytic cell, and electrolyzing the aqueous solution of hypochlorous solution to produce a chloric acid solution. Using the process of the invention, chloric acid can be produced efficiently at substantially reduced production costs using a process which can be operated commercially. In addition, the chloric acid solutions produced are of high purity and are stable at ambient conditions.

Electrochemical process for production of chloric acid from hypochlorous

A process for producing lithium hypochlorite which admixes an aqueous hypochlorous acid solution, having a concentration of 35 percent or greater by weight of HOCl, with an aqueous slurry of lithium hydroxide at a temperature in the range of from about 0.degree. to about 20.degree. to produce a solution of substantially pure lithium hypochlorite. The lithium hypochlorite solutions produced can be dried directly or concentrated by cooling. The solid lithium hypochlorite produced is a highly pure source of available chlorine.

Process for the production of lithium hypochloride

A process for producing chlorine dioxide by oxidizing a hypochlorous acid solution to produce a chloric acid solution, and, electrolyzing the chloric acid solution to produce chlorine dioxide. The novel process of the present invention provides a commercially viable process for producing the chloric acid and eliminates the formation of an acidic salt solution in the production of chlorine dioxide which requires disposal. Further, the process permits a reduction in the amount of acid required in the generation of chlorine dioxide.

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Athens, TN, United States of America

Budd L Duncan