A gas turbine engine system (100) is provided. The gas turbine engine includes a gas turbine engine (10) comprising at least one compressor (14,18,118), at least one combustion chamber (22,120) downstream from the at least one compressor, and at least one turbine (26,30,122) downstream from the at least one combustion chamber, the at least one combustion chamber coupled in flow communication to a source of hydrocarbonaceous fuel (130) and to a source of oxygen (132), the gas turbine engine operable with a working fluid (150) that is substantially nitrogen-free, an exhaust gas (108) conditioning system (112) coupled between a discharge outlet of the gas turbine engine and an inlet of the gas turbine engine, the exhaust gas conditioning system receives all of the exhaust discharged from the gas turbine engine, and a sequestration chamber (142) for storing carbon dioxide, the sequestration chamber coupled to the gas turbine engine for receiving working fluid bled from the turbine upstream from the at least one combustion chamber.