Performance characteristics of an integrated power generation system combining gas turbine combined cycle, carbon capture and methanation

This study analyzes the performance of an integrated power generation system that combines a gas turbine combined cycle (GTCC) with a methanation process. The methanation process uses hydrogen provided by a power-to-gas (PtG) process and carbon dioxide captured from the exhaust gas of the GTCC. The research aim was to maximize the GTCC performance through an effective integration between the GTCC and methanation. Two methods were proposed to utilize the steam generated from the methanation process. One was to supply it to the steam turbine bottoming cycle of the GTCC, and the other was to inject it into the GT combustor. Also investigated was the injection of oxygen generated in the PtG process into the gas turbine combustor. The largest improvements in the power and efficiency were predicted to be 19.3 % and 4.9 % through the combination of the steam supply to the bottoming cycle and the oxygen injection to the combustor.