Reducing nitrogen oxides to nitrogen - without excessive generation of smoke or carbon monoxide

摘要

Gases contg. N oxides are converted into safely ventable gases by (a) burning a fuel in a first zone in the presence of >=65% but =100% stoichiometric O2 requirement, (b) mixing the combustion prod. with the gases contg. N oxides to produce an excess of oxidisable combustion prods. over O available from the oxides, (c) cooling the combustion mixt. to maintain a temp. of 1200-2000 degrees F., for reducing the N oxides, (d) mixing in a second zone, oxidisable combustion prods. remaining after redn. of the N oxides with enough O2 to convert them to CO2 and H2O without reformation of N oxides and (e) venting the resultant gas prod.