Olin Corporation

The Procter Gamble Company

David W Cawlfield

Jerry J Kaczur

Kenneth E Woodard, Jr

Budd L Duncan

Sudhir K Mendiratta

James M Ford

Sanders H Moore

Ronald L Dotson

Roger E Bolick, Ii

Robert T Brooker

Harry J Loftis

Jimmy M French

Leslie R Ward

Julian F Watson

Richard C Ness

Donald B Loftis

Awuri Priye Asuru

Jerry J Kazcur

Randall Taylor Morris

Jay S Stirrat

Leonard L Scott

Paul Thomas Weisman

Trevor Walker

John L Stubbs, Jr

Paul J Craney

Allen Dale Early

Hassan Arabghani

Cortie J Rolison, Iii

Elizabeth K Walter

Elizabeth K Muse

William M Moore

Joan A Mabesoone

Guy Whitfield

The present invention provides compositions comprising comminuted sodium hypochlorite pentahydrate crystals with an average length-to-diameter ratio of less than about 20:1, and a mother liquor saturated in sodium hypochlorite, which has excess alkalinity and/or one or more additional alkali or alkali earth metal salts. Processes for preparing these compositions will be presented.

Sodium hypochlorite compositions

A sodium hypochlorite composition comprising between about 25% and about 40% sodium hypochlorite, in the form of a slurry of sodium hypochlorite pentahydrate crystals in a mother liquor saturated in sodium hypochlorite. The composition can include sodium chloride, and an alkai stabilizer such as sodium hydroxide and sodium carbonate. The slurry is preferably between about &#x2212;15&#xb0; C. and about 10&#xb0; C. A method of transporting or storing sodium hypochlorite is also provided in which the sodium hypochlorite is in the form of a slurry of sodium hypochlorite pentahydrate crystals in a mother liquor saturated in sodium hypochlorite. The composition can include sodium chloride, and an alkali stabilizer such as sodium hydroxide and sodium carbonate. The slurry is preferably between about &#x2212;15&#xb0; C. and about 10&#xb0; C.

Sodium hypochlorite composition and method of storing and transporting sodium hypochlorite

Automatic control systems, and corresponding processes, for controlling either an anode adjuster in a chlor/alkali cell or at least one average middle temperature of a distillation column wherein the combination of feedback control from at least one real unit operation variable and an embedded real-time dynamic simulation of that variable are used.

Automatic control system for unit operation

The present invention relates to a multi-step process for producing HAN that is free of ammonium nitrate. The process comprises the steps of: (a) stripping ammonia from an ammonia-containing, aqueous hydroxylamine solution having a hydroxylamine concentration of at least 10% by weight based upon the weight of the hydroxylamine solution, by contacting the ammonia-containing hydroxylamine solution with a stripping agent selected from the group consisting of inert gases and steam to provide an ammonia-free, aqueous hydroxylamine solution, and (b) reacting the ammonia-free, aqueous hydroxylamine solution with aqueous nitric acid having an acid concentration of at least about 0.1%, preferably at least about 20%, based upon the weight of the aqueous nitric acid, to produce ammonium nitrate-free HAN. In another process embodiment of the invention, the above-described ammonia stripping step is not required, and the hydroxylamine concentration is at least about 0.5%, based upon the weight of the reaction mixture employed. Also disclosed is the ammonium nitrate-free HAN product produced by the process of this invention.

Hydroxylammonium nitrate free of ammonium nitrate

A process and apparatus for producing chlorine dioxide comprising chemically reducing chloric acid with water in the presence of any oxygen-evolving catalyst and in the absence of another acid or an added reducing agent, thereby producing chlorine dioxide and oxygen.

Catalytic process for chlorine dioxide generation from chloric acid

A model predictive control apparatus and method for controlling the operation of a process having a process input signal and a process output signal, which includes determining a predicted process output signal at a future steady state condition according to a process model, determining a steady state error signal according to the difference between the predicted process output signal and a desired set point signal, and determining a set of future process input change signals required to correct for the estimated steady state error by providing at least one step response in the process output at a future time. The next net process input change is then applied according to the sum of the currently determined first element of the set of future process input change signals summed with any future process input change signals that were previously calculated for the next process input change signal that is calculated according to this method. The model is expressed in velocity form. Process tuning parameters are available to dampen the net process input change as well as the currently determined first element of the process input change with respect to a process input change signal that is calculated according to the steady state error divided by the steady state process gain.

Model predictive control apparatus and method

A process for gas phase delignifying wood pulp comprising: contacting wood pulp in the first stage of pulp bleaching with chlorine dioxide-containing gas to delignify said wood pulp; wherein

Process for gas phase delignifying wood pulp using chlorine dioxide at

A bipolar water ionizing electrode and a process employing such an electrode in an electrodialytic cell are disclosed. The cell has a plurality of ion exchange compartments separated by cation permselective membranes and the bipolar water ionizing electrode. The bipolar electrode is permeable to gas and electric current and impervious to liquid.

Water ionizing electrode and electrochemical process for using

A process for producing manganese dioxide and zinc metal comprising the steps of:

Integrated process of using chloric acid to separate zinc oxide and

A process for removing alkaline earth metal impurities (e.g. calcium and magnesium ions) from an aqueous alkali metal chlorate solution which includes adding sufficient alkali metal carbonate or hydroxide or both to the impure solution to raise the pH to above 9 and form alkaline earth metal precipitates which are then removed from the pH-adjusted solution (e.g. by microfiltration). This process can lower the level of these impurities from about 1-20 ppm to less than about 0.3 ppm or less.

Purification of aqueous alkali metal chlorate solutions

A process for producing manganese dioxide comprising the steps of: (1) reacting manganese oxide with a molar excess of an aqueous chloric acid solution in a reaction zone to form a reaction mixture in said zone comprising chlorine gas, a solid phase containing manganese dioxide, and a liquid phase containing chloric acid and water; the concentration of chloric acid in said liquid phase is greater than about 5% by weight of said liquid phase upon leaving the reaction zone; (2) separating said chlorine gas from said solid phase and said liquid phase; (3) separating said solid phase containing manganese dioxide from liquid phase containing chloric acid and water; (4) removing water from said separated liquid phase to concentrate said chloric acid in said separated liquid phase; and (5) returning said separated and concentrated liquid phase back to said reaction zone for further reaction with manganese oxide.

Process for producing solid manganese dioxide

The present invention relates to an electrochemical process for the removal of excess or residual nitric acid from aqueous hydroxylammonium nitrate (HAN) solutions. The process utilizes a multi-compartment electrochemical membrane cell in which the HAN solution flows through a central ion exchanging compartment bounded by anion membranes on either side. Electrochemically generated OH-ions formed at the cathode are used to displace and remove the nitric acid from the HAN solution. In use, the residual nitric acid content in the HAN is suitably reduced to a specified safe level before the HAN is concentrated to a 13.0 molar final composition.

Electrochemical process for the removal of residual nitric acid from

A process for electrochemically treating an aqueous solution containing inorganic oxynitrogen species is disclosed in which the aqueous solution is fed into the catholyte compartment of an electrochemical reduction cell using a high surface area cathode separated from an anolyte compartment to electrochemically reduce substantially all of the oxynitrogen species to nitrogen or ammonia and produce a purified water product.

Process for the removal of oxynitrogen species for aqueous solutions

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.

Growing community of inventors

Cleveland, TN, United States of America

David W Cawlfield