A method of separating carbon dioxide (CO2) from nitrogen (N2) and oxygen (O2) within a turbine engine system includes, in an exemplary embodiment, directing an air stream into an air separation unit (ASU), separating N2 from the air stream in the ASU to form an oxygen (O2) rich air stream, and directing the O2 rich air stream to the combustor to mix with a fuel for combustion forming hot combustion gases, containing O2 and CO2, which are used to rotate the turbine. The method also includes directing turbine expander exhaust gases to a heat recovery steam generator (HRSG) to create steam, directing exhaust from the HRSG to a condenser to separate water from a mixture of O2 and CO2 gases, and directing the mixture of O2 and CO2 gases to a separation system where the CO2 is separated from the O2 gases and removed from the separation system.