EXHAUST EMISSION CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To purify NOx and the like in lean combustion exhaust gas in an internal combustion engine. SOLUTION: Ammonia is manufactured from exhaust gas at the time of combustion in a stoichiometric air-fuel ratio or a rich condition, the ammonia is mixed with lean combustion exhaust gas, and NOx in the lean combustion exhaust gas is reduced and purified by the ammonia. It is thus possible to effectively purify NOx in the lean combustion condition.