Patent ID: 7875459

Claim:
A method for managing one or more denitration catalysts in an exhaust-gas denitration system, the method comprising: measuring [NH 3 ] and [NO x ] at an inlet and an outlet of each denitration catalyst; measuring extent of deterioration of each denitration catalyst in consideration of both [NH 3 ] and [NO x ]; and determining, based on nature of deterioration, which one of the following processes is to be performed (1) regeneration of the denitration catalysts; (2) replacement of the denitration catalysts; or (3) neither of the regeneration nor the replacement is performed, wherein the extent of deterioration is determined by calculating a denitration ratio (η) according to the following equation (2): η ⁢ ( inlet ⁢ ⁢ NH 3 - outlet ⁢ ⁢ NH 3 ) ( inlet ⁢ ⁢ NH 3 - outlet ⁢ ⁢ NH 3 + outlet ⁢ ⁢ NO x ) × 100 × evaluation ⁢ ⁢ mole ⁢ ⁢ ratio inlet ⁢ ⁢ mole ⁢ ⁢ ratio . ⁢ ( 2 )