System and method of operating a power generation system with an alternative working fluid

A gas turbine engine system comprising:

• at least a first gas turbine engine, a second gas turbine engine, and a last gas turbine engine of a plurality of substantially identical gas turbine engines coupled together in serial flow communication wherein each gas turbine engine downstream of said first gas turbine engine receives all of a substantially nitrogen-free exhaust from the gas turbine engine directly upstream and wherein each gas turbine engine upstream of said last gas turbine engine discharges a respective substantially nitrogen-free exhaust to the gas turbine engine directly downstream, each of said gas turbine engines comprises at least one compressor, at least one combustion chamber and at least a low pressure turbine and a high pressure turbine downstream from said combustion chamber, each said combustion chamber is coupled in flow communication to a source of hydrocarbonaceous fuel and to a source of oxygen, a working fluid of each said gas turbine engine being substantially nitrogen-free;
• and
• an exhaust gas conditioning system coupled between a discharge outlet of the last of said gas turbine engines coupled together in said system and an inlet of the first of said gas turbine engines coupled together in said system, said exhaust gas conditioning system configured to remove heat and water vapor from exhaust gases only from said last gas turbine engine to generate a flow of conditioned exhaust gas and to direct the flow of conditioned exhaust gas to said first gas turbine engine as a gas turbine engine working fluid, wherein said exhaust gas conditioning system is the only exhaust gas conditioning system coupled to the plurality of substantially identical gas turbine engines.