Patent ID: 8495858

Claim:
A method of implementing an auxiliary power output of a gas turbine power plant to reduce emissions of the power plant, the method comprising: providing a gas turbine and generator assembly; operating the gas turbine with a fuel to produce a hot working medium producing work and creating an expanded working medium; removing heat from the expanded working medium leaving the gas turbine in a heat recovery steam generator (HRSG) to form a reduced temperature exhaust gas; generating steam in the HRSG from the heat removed from the expanded working medium; passing the reduced temperature exhaust gas through a selective catalytic reduction (SCR) system; providing an auxiliary plant power unit comprising a steam turbine and generator assembly; operating the steam turbine with the steam generated in the HRSG to produce an expanded steam exhaust, and producing an auxiliary plant output at the generator connected to the steam turbine; and using the auxiliary plant output to produce a supply of dilution air, and providing the dilution air to the reduced temperature exhaust gas to effect a further reduction of temperature of the exhaust gas prior to passing the reduced temperature exhaust gas through the SCR system.