Device for purifying I.C. engine exhaust gas contains a nitrogen monoxide production unit to enrich the exhaust gas fed to the ammonia production catalyst with nitrogen monoxide during ammonia production operating phases

摘要

A nitrogen monoxide production unit enriches the exhaust gas fed to the ammonia production catalyst with nitrogen monoxide during ammonia production operating phases. Exhaust gas purification device comprises an ammonia production catalyst (4) for producing ammonia using the components of at least one part of the exhaust gas emitted from the engine (1) during ammonia-producing operating phases; a nitrogen oxide reduction catalyst (3) connected to the ammonia-producing catalyst to reduce nitrogen oxides produced in the emitted exhaust gas using the ammonia produced as reductant; and a nitrogen monoxide production unit (5) which enriches the exhaust gas fed to the ammonia production catalyst (4) with nitrogen monoxide during ammonia production operating phases. Preferred Features: The nitrogen monoxide production unit contains a plasma generator to oxidize nitrogen contained in the gas stream into nitrogen monoxide.