Exhaust gas cleaning device with internal generation of ammonia for the reduction of nitrogen oxides and method for operating the same

摘要

The ammonia-producing catalyst is arranged in an exhaust gas pipe branch (3a) connected to a first part (2a) of the combustion source (2a-2d) leading to the nitrogen oxides-reducing catalyst, whilst one or more exhaust gas pipe branches (3b, 3c, 3d) are connected to the remaining combustion sources (2b-2d) which lead to the nitrogen oxides-reducing catalyst. Exhaust gas purification device has an ammonia-producing catalyst (4) for producing ammonia from nitrogen oxides contained in the waste gas to be purified, and a nitrogen oxides-reducing catalyst (5) arranged downstream of the ammonia-producing catalyst for reducing nitrogen oxides contained in the exhaust gas to be purified using the ammonia as the reductant. The ammonia-producing catalyst is arranged in a exhaust gas pipe branch (3a) connected to a first part (2a) of the combustion source (2a-2d) leading to the nitrogen oxides-reducing catalyst, whilst one or more exhaust gas pipe branches (3b, 3c, 3d) are connected to the remaining combustion sources (2b-2d) which lead to the nitrogen oxides-reducing catalyst.