摘要 |
PROBLEM TO BE SOLVED: To simplify and miniaturize a device by denitrating nitrogen oxides in exhaust gas having a specified temperature from a final outlet of an exhaust gas recovery device by a low temperature denitration catalyst. SOLUTION: Since an exhaust gas temperature just rear side of an outlet in an internal combustion engine such as a diesel engine used in a co-generation system is set to 500 deg.C or more, taken-out heat of exhaust gas is once recovered by an exhaust heat recovering device, and exhaust heat is recovered until a combustion exhaust gas temperature becomes 200 deg.C and less. Exhaust gas from an outlet of the exhaust heat recovering device is denitrated at 200 deg.C or less using a low temperature denitration catalyst. In the low temperature denitration catalyst, activated carbon fiber is used as a carrier, and oxide of metal such as Mn, Fe, Co, Ni is carried as a catalyst activated main component. The carrier is assembled with the catalyst activated component so as to constitute a denitration device operated at 200 deg.C or less. |