A closed loop oxy-fuel combustion power generation cycle is disclosed. The closed cycle has a gas generator which combusts oxygen with a hydrocarbon fuel to produce a drive gas mixture of steam and carbon dioxide that drives a turbine directly with the drive gas mixture. The drive gas mixture then enters a condenser where carbon dioxide is removed and water is recirculated to a heat exchanger where heat is transferred from the drive gas mixture to the water, to produce high pressure steam. This high pressure steam acts as a separate drive gas for a steam turbine. This steam is only indirectly heated by the gas generator through the heat exchanger, such that the cycle includes both direct and indirect heating of working fluids. Water/steam downstream from the steam turbine is then routed back to the gas generator or downstream of the gas generator to close the cycle.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 This invention was made with Government support under Collaborative Research Agreement No. DE-FC26-05NT42465 awarded by the Department of Energy. The Government has certain rights in this invention.