Olin Corporation

Diamond Shamrock Corporation

Other

Ronald L Dotson

Kenneth E Woodard, Jr

Sanders H Moore

Richard W Lynch

David W Cawlfield

Han C Kuo

Budd L Duncan

Sudhir K Mendiratta

Byung K Ahn

Harry J Loftis

David D Justice

Garland E Hilliard

Kevin J O'Leary

J Paul Deininger

Robert T Brooker

Ronald C Miles

Richard W Ralston, Jr

Debra Y Hernandez

Jay S Stirrat

Edward P Carr

Jerry J Kaczur

Andrew D Babinsky

Larry D Carpenter

James F Pickering

George W Geren

Carey O Burger

Robert K Steely

Jeffery D Casteel

Ronald A Sasse

Phillip J Reed

Richard E Mellor

George M Shipley

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 for the removal of mercury from industrial waste streams is disclosed wherein the waste stream is a nitrate based solution that has been decomposed by the addition of hypochlorite. The method involves adding a reducing agent to reduce the hypochlorite and/or adjusting the pH by the use of a strong acid to less than about 2.0, converting any residual chlorine to a soluble unreactive salt, adding a soluble precipitating agent, such as sodium sulfide, to the solution in a ratio to the mercury present of greater than 1:1 to about 2:1 to precipitate out the mercury as a mercury compound. The solution is then filtered to remove the precipitated mercury compound.

Process for removal of mercury from hydroxyl-ammonium nitrate solutions

A method and system for treating liquid chlorine to remove inert gases therefrom. Liquid chlorine is treated by passing it through a molecular sieve having a molecular pore diameter greater than the molecular diameter of the inert gases and smaller than the molecular diameter of chlorine so that the inert gases are adsorbed by the sieve while the liquid chlorine passes therethrough. The sieve may be regenerated by heating the sieve and evacuating by vacuum, followed by a purging with a gas and then a further vacuum evacuation.

Process for removal of inert gases from liquid chlorine and system

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

Ammonium perchlorate is produced a process which comprises:

Process for producing perchloric acid and ammonium perchlorate

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 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.

Electrochemical process for producing chlorine dioxide from chloric acid

A process for decomposing a solution of a hydroxylammonium compound includes raising the pH of the solution to about 8 or higher and reacting the alkaline solution with a source of hypohalite ions. The process decomposes solutions of hydroxylammonium salts in a manner which produces benign liquid and gas effluents which can be readily disposed of or discharged.

Process for decomposing solutions of hydroxylammonium salts

A process for reducing excess nitric acid in an aqueous hydroxylamine nitrate solution. The process is conducted by reacting the aqueous hydroxylamine nitrate solution with a basic neutralizing agent such as nitric oxide, hydroxylamine vapor or a mixture thereof or by contacting the aqueous hydroxylamine nitrate solution with an anion exchange resin having a pKa in the range of from about 5 to about 9. The aqueous hydroxylamine nitrate solution may be produced by the electrolysis of nitric acid.

Method of reducing excess nitric acid in aqueous hydroxylamine nitrate

Concentrated solutions of inorganic hydroxylammonium salts can safely be produced in a process for concentrating a dilute solution of an inorganic hydroxylammonium salt by contact with a membrane having a sorption side and a desorption side. The process comprises contacting the dilute solution with the sorption side of a membrane, which is substantially permeable to the solvent and substantially impermeable to the solute of the solution, to sorb the solvent and permit the solvent to flow through the membrane to the desorption side. Desorbing the solvent from the desorption side of the membrane. Highly concentrated aqueous solutions of hydroxylammonium salts which are heat sensitive are produced by the novel process of the invention which does not require directly heating the solution and is substantially free of hazards.

Process for concentrating aqueous solutions of hydroxylammonium salts

A solution of hydroxylamine nitrate is electrolytically produced in an electrochemical cell having a cathode compartment, an anode compartment, and a separator between the cathode compartment and the anode compartment. The process comprises feeding a catholyte consisting essentially of an aqueous nitric acid solution to the cathode compartment. An anolyte solution is fed to the anode compartment. The catholyte is electrolyzed while maintaining the cathodic reaction temperature below about 50.degree. C. and a cathode half-cell potential at from about -0.5 to about -3 volts to produce a hydroxylamine nitrate solution which is recovered from the cathode compartment. The novel process of the present invention directly produces highly concentrated hydroxylamine nitrate solutions of high purity, i.e., suitable for use in a monopropellant.

Direct electrochemical reduction of nitric acid to hydroxylamine nitrate

A process for the electrolysis of an aqueous solution of an alkali metal halide in an electrolytic cell having an anode compartment containing at least one anode, a cathode compartment containing at least one cathode, and a cation exchange membrane separating the anode compartment from the cathode compartment comprises feeding the aqueous solution of an alkali metal halide to the anode compartment; feeding an oxygen-containing gas to the cathode compartment; and electrolyzing the alkali metal halide solution to produce a halogen gas and alkali metal ions in the anode compartment. The alkali metal ions and water are passed through the cation exchange membrane into the cathode compartment to contact a hydrophilic porous cathode. The alkali metal ions, the water and the oxygen-containing gas produce a concentrated alkali metal hydroxide solution which flows through a hydrophilic porous cathode. The concentrated alkali metal hydroxide solution is removed from the cathode compartment to prevent a substantial accumulation of the concentrated alkali metal hydroxide solution in the cathode compartment. The process of the present invention provides operation of the membrane all independently of oxygen gas and liquid diffusion rates to permit high current densities to be employed.

Electrolysis of alkali metal chloride brine in catholyteless membrane

An electrode for use in an electrolytic cell, wherein the electrode comprises a conductor and an element of a second metal, at least a portion of each having contact surfaces being held in intimate contact with the other, said conductor and said element each having a conductive coating applied to the contact surface, said conductive coating comprising between about 20 and about 30 percent indium and between about 80 and about 70 percent gallium, whereby the contact resistance between said conductor and said element is reduced.

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Cleveland, TN, United States of America

Ronald L Dotson