Catalytic redn. of nitrogen oxides in gas - using dehydrated alpha-goethite as catalyst for economy and high activity

摘要

In the treatment of gas contg. N oxide (I) by catalytic redn. with ammonia (II) or CO1 the catalyst used is Fe (III) oxide (III) obtd. by dehydration of alpha-goethite (alpha-FeOOH), pref. at 250-750, esp. 300-700 degrees C. The gas can also contain SOx. Used for the treatment of waste gases from engine exhausts, combustion furnaces, roasters, nitric acid mfr., metal surface treatment units etc. (III) has extremely high catalytic activity and is inexpensive. In an example, 97-99% removal of (I) from a gas was achieved by redn. with (II) over (III) dehydrated at 300-600 degrees C, at a treatment temp. of 300 degrees C.