Methods for making chlorine dioxide

Abstract

Chlorine dioxide is generated in a controlled manner from chlorous acid by catalysis. Chlorine dioxide can be generated either subsequent to the generation of chlorous acid or simultaneously with the generation of chlorous acid. For catalysis of chlorous acid to chlorine dioxide, the chlorous acid may be generated by ion exchange or in a conventional manner.

1 . A process for generating chlorine dioxide from chlorous acid which comprises contacting chlorous acid with an insoluble catalytic material in a moist environment for a time sufficient to form chlorine dioxide.  
     
     
         2 . The process of  claim 1  wherein said catalytic material is deposited on an ion exchange material.  
     
     
         3 . The process of  claim 1  wherein said catalytic material is an ion exchange material.  
     
     
         4 . The process of  claim 1  wherein said catalytic material is deposited on an inorganic or organic substrate.  
     
     
         5 . The process of  claim 4  wherein said catalytic material comprises platinum coated acid-washed carbon particles.  
     
     
         6 . The process of  claim 1  wherein said catalytic material comprises a mixture of a first and second ion exchange material and said second ion exchange material has a catalyst deposited on the surface of the material.  
     
     
         7 . The process of  claim 1  wherein said catalytic material comprises a mixture of a first and second substrate material and said second substrate material has a catalyst deposited on the surface of the material.  
     
     
         8 . The process of  claim 1  wherein said catalytic material is selected from the group consisting of platinum, palladium, manganese dioxide, and carbon.  
     
     
         9 . The process of  claim 6  wherein said catalytic material is selected from the group consisting of platinum, palladium, manganese dioxide, and carbon.  
     
     
         10 . The process of  claim 2  wherein said ion exchange material is selected from the group consisting of inorganic resins, organic resins, membranes, powders and gels.  
     
     
         11 . The process of  claim 3  wherein said ion exchange material is selected from the group consisting of inorganic resins, organic resins, membranes, powders and gels.  
     
     
         12 . The process of  claim 2  wherein said ion exchange material is selected from the group consisting of a weak acid cation exchange resin or powder, a strong acid cation exchange resin or powder, a weak base anion exchange resin or powder, and strong base anion exchange resin or powder.  
     
     
         13 . The process of  claim 3  wherein said ion exchange material is selected from the group consisting of a weak acid cation exchange resin or powder, a strong acid cation exchange resin or powder, a weak base anion exchange resin or powder, and strong base anion exchange resin or powder.  
     
     
         14 . The process of  claim 2  wherein said ion exchange material is disposable.  
     
     
         15 . The process of  claim 3  wherein said ion exchange material is disposable.  
     
     
         16 . The process of  claim 2  wherein said ion exchange material is regenerable.  
     
     
         17 . The process of  claim 3  wherein said ion exchange material is regenerable.  
     
     
         18 . The process of  claim 1  wherein said moist environment is an aqueous solution.  
     
     
         19 . A process for generating chlorine dioxide from chlorous acid which comprises contacting chlorous acid with a inorganic cation exchange material having a catalyst deposited on the surface of said material, in a moist environment for a time sufficient to form chlorine dioxide.  
     
     
         20 . The process for generating chlorine dioxide from chlorous acid of  claim 19 , wherein said catalyst comprises manganese dioxide.  
     
     
         21 . The process for generating chlorine dioxide from chlorous acid of  claim 19 , wherein said catalyst comprises platinum.  
     
     
         22 . A process for generating chlorine dioxide from chlorous acid which comprises contacting chlorous acid with an organic anion exchange material having palladium deposited on the surface of said material, in a moist environment for a time sufficient to form chlorine dioxide.  
     
     
         23 . A process for generating chlorine dioxide which comprises: 
 a) contacting a chlorite salt solution with a cation exchange material in the hydrogen form in a moist environment for a time sufficient to effect an essentially complete substitution of cations in the chlorite salt with hydrogen ions on the cation exchange material to form chlorous acid; and    b) contacting the chlorous acid produced in step a) with a catalytic material in a moist environment for a time sufficient to form chlorine dioxide.    
     
     
         24 . The process of  claim 23  wherein said catalytic material is deposited on an ion exchange material.  
     
     
         25 . The process of  claim 23  wherein said catalytic material is an ion exchange material.  
     
     
         26 . The process of  claim 23  wherein said catalytic material is deposited on an inorganic or organic substrate.  
     
     
         27 . The process of  claim 26  wherein said catalytic material comprises platinum coated acid-washed carbon particles.  
     
     
         28 . The process of  claim 23  wherein said catalytic material comprises a mixture of a first and second ion exchange material and said second ion exchange material has a catalyst deposited on the surface of the material.  
     
     
         29 . The process of  claim 23  wherein said catalytic material comprises a mixture of a first and second substrate material and said second substrate material has a catalyst deposited on the surface of the material.  
     
     
         30 . The process of  claim 23  wherein said catalytic material is selected from the group consisting of platinum, palladium, manganese dioxide, and carbon.  
     
     
         31 . The process of  claim 28  wherein said catalytic material is selected from the group consisting of platinum, palladium, manganese dioxide, and carbon.  
     
     
         32 . The process of  claim 24  wherein said ion exchange material is selected from the group consisting of inorganic resins, organic resins, membranes, powders and gels.  
     
     
         33 . The process of  claim 25  wherein said ion exchange material is selected from the group consisting of inorganic resins, organic resins, membranes, powders and gels.  
     
     
         34 . The process of  claim 24  wherein said ion exchange material is selected from the group consisting of a weak acid cation exchange material or powder, a strong acid cation exchange material or powder, a weak base anion exchange resin or powder, and strong base anion exchange resin or powder.  
     
     
         35 . The process of  claim 25  wherein said ion exchange material is selected from the group consisting of a weak acid cation exchange resin or powder, a strong acid cation exchange resin or powder, a weak base anion exchange resin or powder, and strong base anion exchange resin or powder.  
     
     
         36 . The process of  claim 24  wherein said ion exchange material is disposable.  
     
     
         37 . The process of  claim 25  wherein said ion exchange material is disposable.  
     
     
         38 . The process of  claim 24  wherein said ion exchange material is regenerable.  
     
     
         39 . The process of  claim 25  wherein said ion exchange material is regenerable.  
     
     
         40 . The process of  claim 23  wherein said moist environment is an aqueous solution.  
     
     
         41 . A process for generating chlorine dioxide from chlorous acid which comprises the following steps: 
 a) contacting a chlorate salt solution with a cation exchange material in the hydrogen form in a moist environment for a time sufficient to to effect an essentially complete substitution of cations in the chlorate salt with hydrogen ions on the cation exchange material to form chlorous acid; and    b) contacting the chlorous acid produced in step a) with an catalytic material in a moist environment for a time sufficient to form chlorine dioxide.    
     
     
         42 . The process of  claim 41  wherein said catalytic material is deposited on an ion exchange material.  
     
     
         43 . The process of  claim 41  wherein said catalytic material is an ion exchange material.  
     
     
         44 . The process of  claim 41  wherein said catalytic material is deposited on an inorganic or organic substrate.  
     
     
         45 . The process of  claim 44  wherein said catalytic material comprises platinum coated acid-washed carbon particles.  
     
     
         46 . The process of  claim 41  wherein said catalytic material comprises a mixture of a first and second ion exchange material and said second ion exchange material has a catalyst deposited on the surface of the material.  
     
     
         47 . The process of  claim 41  wherein said catalytic material comprises a mixture of a first and second substrate material and said second substrate material has a catalyst deposited on the surface of the material.  
     
     
         48 . The process of  claim 46  wherein said catalytic material is selected from the group consisting of platinum, palladium, manganese dioxide, and carbon.  
     
     
         49 . The process of  claim 47  wherein said catalytic material is selected from the group consisting of platinum, palladium, manganese dioxide, and carbon.  
     
     
         50 . The process of  claim 42  wherein said ion exchange material is selected from the group consisting of inorganic resins, organic resins, membranes, powders and gels.  
     
     
         51 . The process of  claim 43  wherein said ion exchange material is selected from the group consisting of inorganic resins, organic resins, membranes, powders and gels  
     
     
         52 . The process of  claim 42  wherein said ion exchange material is selected from the group consisting of a weak acid cation exchange resin or powder, a strong acid cation exchange resin or powder, a weak base anion exchange resin or powder, and strong base anion exchange resin or powder.  
     
     
         53 . The process of  claim 43  wherein said ion exchange material is selected from the group consisting of a weak acid cation exchange resin or powder, a strong acid cation exchange resin or powder, a weak base anion exchange resin or powder, and strong base anion exchange resin or powder.  
     
     
         54 . The process of  claim 42  wherein said ion exchange material is disposable.  
     
     
         55 . The process of  claim 43  wherein said ion exchange material is disposable.  
     
     
         56 . The process of  claim 42  wherein said ion exchange material is regenerable.  
     
     
         57 . The process of  claim 43  wherein said ion exchange material is regenerable.  
     
     
         58 . The process of  claim 41  wherein said moist environment is an aqueous solution.