Abstract: A system and method of treating an exhaust flow including nitrogen oxides (NOx) in a turbine engine power generation plant is provided. The turbine engine has a selective catalytic reduction system having a catalyst. During steady state operation of the engine, a reducing agent, such as ammonia, is supplied to an injector in an amount based on a measured molar flow of NOx in the exhaust flow. During a disturbance in the operation of the turbine engine, a reducing agent is supplied to the injector in an amount based on a predicted molar flow of NOx in the exhaust flow. In addition, the system can include a biasing feature in which additional reducing agent is supplied to the exhaust flow beyond the predicted molar flow of NOx. The system and method can mitigate NOx during transient engine operation, an operational mode in which emissions are difficult to predict and control.

Abstract: A system and method of treating an exhaust flow including nitrogen oxides (NOx) in a turbine engine power generation plant is provided. The turbine engine has a selective catalytic reduction system having a catalyst. During steady state operation of the engine, a reducing agent, such as ammonia, is supplied to an injector in an amount based on a measured molar flow of NOx in the exhaust flow. During a disturbance in the operation of the turbine engine, a reducing agent is supplied to the injector in an amount based on a predicted molar flow of NOx in the exhaust flow. In addition, the system can include a biasing feature in which additional reducing agent is supplied to the exhaust flow beyond the predicted molar flow of NOx. The system and method can mitigate NOx during transient engine operation, an operational mode in which emissions are difficult to predict and control.

Abstract: A method of operating an electric power generation system (2). In one embodiment, a combustion chamber receives a combination of pressurized air (14) flow output from a compressor (12) and fuel (20) for combustion therein. The system (2) is operated at a relatively high steady state level of power output and then power is turned down by extracting a portion (34) of the pressurized air (14) flow before entry into the combustor (16). The method may further include throttling of air (14) flowing through the compressor (12) with inlet guide vanes (15). Features of the reduction in power include maintaining a characteristic combustor (16) minimum flame temperature with a volumetric percentage of NOx or CO emissions not exceeding those corresponding to the relatively high steady state operation.