A gas turbine includes a compressor, a turbine downstream of the compressor having stators, and a rotor connecting the compressor to the turbine. The rotor includes rotor cavities. A supply plenum containing a process by-product gas and a control valve is connected to at least one of the rotor cavities to supply the process by-product gas to at least one of the rotor cavities. A process for operating a gas turbine having a compressor and a turbine includes connecting the compressor to the turbine by a rotor, creating cavities in the rotor, and injecting a process by-product gas into at least one of the cavities. The process further includes regulating the flow of the process by-product gas into at least one of the cavities according to a pre-programmed parameter.