| 摘要 |
PROBLEM TO BE SOLVED: To provide a waste combustion gas denitrating method suitable for measures on waste gas being at low temperature such as on startup of a combustion plant or for denitration of waste gas in a low temperature part. SOLUTION: In a method of passing waste combustion gas through an ammonia reducing denitration device 2 to denitrate it, a bypass in which a low temperature denitration device 8 is installed is formed on the downstream side of the ammonia reducing denitration device 2 in a waste gas flow passage. When waste gas is at low temperature, it is passed through the bypass to denitrate it by the low temperature denitration device 8, and when the ammonia-reducing denitration device 2 sufficiently functions, denitration is performed by the ammonia reducing denitration device 2, and while a bypass valve is closed, the catalyst in the low temperature denitration device 8 is regenerated. And plural lines of low temperature denitration devices are installed in parallel in a part of the waste gas flow passage in which waste gas is at room temperature to 200 deg.C, and they are switched in order to perform denitration and catalyst regeneration. |
