A method of purifying gases containing nitrogen oxides and an apparatus for purifying gases in a steam generation boiler

Abstract From the Canadian patent

A method of reducing the nitrogen oxide level in the flue gases issuing from combustion units by introduction of reducing agents into contact with gases containing nitrogen oxides in first and second reducing stages is provided. , The first reducing stage is a non-catalytic stage (e.g. at temperatures over 800 ~C), while the second stage is a catalytic stage (e.g. at temperatures of about 300-400 ~C). A steam generation boiler with improved nitrogen reduction facilities is also provided. The amount of nitrogen oxides in the hot gases is reduced in the combination of the first and second reducing stages while producing steam in a steam generation boiler system thus resulting in gases …