Abstract: The closed-loop gas turbine generator is a combustion-based gas reactor for producing usable power to drive external loads. A combustion chamber produces combustion products for driving a first gas turbine, which may be connected to an external load. Exhaust from the first gas turbine is fed to an oxygen transport reactor, which produces carbon dioxide and water as output products. The carbon dioxide and water drive a second gas turbine, which may also be connected to an external load. The first gas turbine drives a compressor, which produces compressed air. Heat exchange between the compressed air and exhaust from the second gas turbine produces a stream of heated air, which is fed back to the combustion chamber in a closed-loop cycle.