Patent ID: 7874141

Claim:
A method of purging an exhaust stream from an exhaust gas recirculation (EGR) system, wherein the exhaust stream is generated by a gas turbine; the method comprising: providing the gas turbine comprising: an inlet, an external combustion system, and an exhaust section; wherein the gas turbine operatively produces an exhaust stream; providing the EGR system comprising: a first zone, a second zone; an EGR skid, an EGR inlet damper, and an EGR outlet damper; wherein the EGR system reduces the level of constituents within the exhaust stream and facilitates the sequestration and removal of the concentrated CO 2 ; providing an EGR purge system comprising: a first purge flow modulation device located within the first zone, a second purge flow modulation device located within the second zone, a purge vent; wherein the EGR purge system operatively uses a benign fluid to remove remnants of the exhaust stream remaining in the EGR system when the EGR system is not in operation; providing a purge gas supply that provides the benign fluid to the EGR purge system, wherein the purge gas supply comprises a purge line; and a purge line isolation device; establishing a pressure balance within the EGR system between the first purge flow modulation device and the second purge flow modulation device; wherein the operation of the purge gas supply establishes a pressure drop between the first zone and second zone as the EGR purge system operates; and utilizing a benign fluid within the purge gas supply to purge the exhausts stream from the EGR system.