• method
  • 3. The method of claim 2 wherein, prior to the reaction of the nitrogen oxides in the gas with sulfurous acid, the gas is contacted by water to remove any components of the gas which inhibit the formation of sulfurous acid from the sulfur dioxide and water. (google.es)
  • 4. The method of claim 1 wherein liquid effluent from the reaction of the gas with sulfurous acid which liquid effluent includes excess sulfur dioxide and nitrogen oxides is added back to the reaction of the sulfurous acid and the gas. (google.es)
  • 5. The method of claim 1 wherein the product of the reaction of the nitrogen oxides in the gas and sulfurous acid, which is converted into a salt by reaction with alkaline solution, is predominantly compounds which are more soluble in and more reactive with said alkaline solution than nitric oxide and nitrogen dioxide. (google.es)
  • 6. The method of claim 1 wherein the reaction of the nitrogen oxides with the sulfurous acid is carried out by countercurrent contacting the sulfurous acid and the gas containing the nitrogen oxides. (google.es)
  • 7. The method of claim 1, wherein the sulfurous acid is produced by reacting water with sulfur dioxide and wherein sulfuric acid is produced in the reaction of the nitrogen oxides and the sulfurous acid and the concentration of the said sulfuric acid is monitored and controlled to prevent the sulfuric acid from reaching a high level at which it inhibits the reaction of the sulfur dioxide and the water. (google.es)
  • 9. The method of claim 7, wherein the solution capacity for sulfur dioxide of the liquid in which the nitrogen oxides are reacted with the sulfurous acid in the wet scrubbing operation is monitored by measuring the oxidation-reduction potential of the liquid and the concentration of sulfuric acid is monitored by measuring the pH of the liquid. (google.es)