SYSTEM FOR TREATING NOx-CONTAINING GAS STREAMS

Abstract

In one embodiment, a system for treating a gas stream comprising NOx generated from an acid pickling solution includes a first chamber and a second chamber. The first chamber includes a first inlet communicating with a source of a gas comprising NOx, a second inlet communicating with a source of ozone, and an interior volume adapted to contact the gas comprising NOx introduced through the first inlet with the ozone introduced through the second inlet. The second chamber directly fluidly communicates with the first chamber and receives gaseous effluent comprising nitric acid from the first chamber. The second chamber includes a third inlet communicating with a source of water vapor, an interior volume adapted to contact the gaseous effluent from the first chamber with the water vapor, thereby solubilizing nitric acid in the gaseous effluent with the water vapor to provide a solubilized nitric acid, and an outlet for collecting solubilized nitric acid from the interior volume of the second chamber.

1 . A system for treating a gas stream comprising NOx generated from an acid pickling solution, the system comprising:
 a first chamber including
 a first inlet communicating with a source of a gas comprising NOx generated by an acid pickling solution in an acid pickling tank, acid pickling bath, or acid pickling spray, 
 a second inlet communicating with a source of ozone, and 
 an interior volume adapted to contact the gas comprising NOx introduced through the first inlet with the ozone introduced through the second inlet, thereby producing oxidation products including nitrogen sesquioxide and nitrogen pentoxide, wherein at least a portion of the nitrogen sesquioxide and nitrogen pentoxide react with water in the first chamber to form nitric acid; and 
   a second chamber directly fluidly communicating with the first chamber and receiving gaseous effluent comprising nitric acid from the first chamber, the second chamber including
 a third inlet communicating with a source of water vapor, 
 an interior volume adapted to contact the gaseous effluent from the first chamber with the water vapor introduced through the third inlet, thereby solubilizing nitric acid in the gaseous effluent with the water vapor to provide a solubilized nitric acid, and 
 an outlet for collecting solubilized nitric acid from the interior volume of the second chamber, wherein the outlet fluidly communicates with the acid pickling tank, acid pickling bath, or acid pickling spray, whereby at least a portion of the solubilized nitric acid collected through the outlet is delivered to the acid pickling tank, acid pickling bath, or acid pickling spray. 
   
     
     
         2 . The system of  claim 1 , wherein the acid pickling tank, acid pickling bath, or acid pickling spray includes an acid pickling solution comprising nitric acid. 
     
     
         3 . The system of  claim 1 , wherein the acid pickling tank, acid pickling bath, or acid pickling spray is used to treat surfaces of materials selected from metals and alloys. 
     
     
         4 . The system of  claim 1 , wherein the acid pickling tank, acid pickling bath, or acid pickling spray is adapted to treat surfaces of materials selected from stainless steel, titanium, and titanium alloys. 
     
     
         5 . The system of  claim 1 , wherein the first chamber includes a static mixer adapted to mix the gas stream comprising NOx and the ozone in the interior volume of the first chamber. 
     
     
         6 . The system of  claim 1 , wherein the first chamber further comprises a third inlet that communicates with a source of water vapor. 
     
     
         7 . The system of  claim 1 , wherein the source of ozone is an ozone generator. 
     
     
         8 . The system of  claim 1 , wherein the second inlet is located adjacent the first inlet. 
     
     
         9 . The system of  claim 1 , wherein a diameter of the first chamber is at least 24 inches. 
     
     
         10 . The system of  claim 1 , wherein the second chamber is a mist eliminator. 
     
     
         11 . A system for treating a gas stream comprising NOx generated from an acid pickling solution, the system comprising:
 a first chamber including
 a first inlet communicating with a source of a gas comprising NOx generated by an acid pickling solution in an acid pickling tank, acid pickling bath, or acid pickling spray, 
 a second inlet communicating with an ozone generator, 
 a third inlet communicating with a source of water vapor, and 
 an interior volume comprising a static mixer adapted to mix the mix the gas comprising NOx introduced through the first inlet with the ozone introduced through the second inlet in the interior volume of the first chamber, thereby producing oxidation products including nitrogen sesquioxide and nitrogen pentoxide, wherein at least a portion of the nitrogen sesquioxide and nitrogen pentoxide react with water in the first chamber to form nitric acid; and 
   a second chamber directly fluidly communicating with the first chamber and receiving gaseous effluent comprising nitric acid from the first chamber, the second chamber including
 a third inlet communicating with a source of water vapor, 
 an interior volume adapted to contact the gaseous effluent from the first chamber with the water vapor introduced through the third inlet, thereby solubilizing nitric acid in the gaseous effluent with the water vapor to provide a solubilized nitric acid, and 
 an outlet for collecting solubilized nitric acid from the interior volume of the second chamber, wherein the outlet fluidly communicates with the acid pickling tank, acid pickling bath, or acid pickling spray, whereby at least a portion of the solubilized nitric acid collected through the outlet is delivered to the acid pickling tank, acid pickling bath, or acid pickling spray. 
   
     
     
         12 . The system of  claim 11 , wherein the acid pickling tank, acid pickling bath, or acid pickling spray includes an acid pickling solution comprising nitric acid. 
     
     
         13 . The system of  claim 11 , wherein the acid pickling tank, acid pickling bath, or acid pickling spray is used to treat surfaces of materials selected from metals and alloys. 
     
     
         14 . The system of  claim 11 , wherein the acid pickling tank, acid pickling bath, or acid pickling spray is adapted to treat surfaces of materials selected from stainless steel, titanium, and titanium alloys. 
     
     
         15 . A system for treating surfaces of materials selected from metals and alloys, the system comprising:
 a pickling apparatus comprising at least one of an acid pickling tank, acid pickling bath, and acid pickling spray;   a first chamber including
 a first inlet communicating with a source of a gas comprising NOx generated by acid pickling solution in the acid pickling tank, acid pickling bath, or acid pickling spray, 
 a second inlet communicating with a source of ozone, and 
 an interior volume adapted to contact the gas comprising NOx introduced through the first inlet with the ozone introduced through the second inlet, thereby producing oxidation products including nitrogen sesquioxide and nitrogen pentoxide, wherein at least a portion of the nitrogen sesquioxide and nitrogen pentoxide react with water in the first chamber to form nitric acid; and 
   a second chamber directly fluidly communicating with the first chamber and receiving gaseous effluent comprising nitric acid from the first chamber, the second chamber including
 a third inlet communicating with a source of water vapor, 
 an interior volume adapted to contact the gaseous effluent from the first chamber with the water vapor introduced through the third inlet, thereby solubilizing nitric acid in the gaseous effluent with the water vapor to provide a solubilized nitric acid, and 
 an outlet for collecting solubilized nitric acid from the interior volume of the second chamber, wherein the outlet fluidly communicates with the acid pickling tank, acid pickling bath, or acid pickling spray, whereby at least a portion of the solubilized nitric acid collected through the outlet is delivered to the acid pickling tank, acid pickling bath, or acid pickling spray. 
   
     
     
         16 . The system of  claim 1 , wherein the pickling apparatus includes an acid pickling solution comprising nitric acid. 
     
     
         17 . The system of  claim 15 , wherein the materials treated in the system are selected from stainless steel, titanium, and titanium alloys. 
     
     
         18 . The system of  claim 15 , wherein the first chamber includes a static mixer adapted to mix the gas stream comprising NOx and the ozone in the interior volume of the first chamber. 
     
     
         19 . The system of  claim 15 , wherein the first chamber further comprises a third inlet that communicates with a source of water vapor. 
     
     
         20 . The system of  claim 15 , wherein the source of ozone is an ozone generator. 
     
     
         21 . The system of  claim 15 , wherein the second inlet is located adjacent the first inlet. 
     
     
         22 . The system of  claim 15 , wherein a diameter of the first chamber is at least 24 inches. 
     
     
         23 . The system of  claim 15 , wherein the second chamber is a mist eliminator.