Carbon capture and storage processes are being researched to reduce carbon dioxide emissions from power plants. This paper proposes a new system that applies an ion transport membrane (ITM) to a triple combined cycle, which includes the gas turbine combined cycle and a solid oxide fuel cell. Two systems which differ in the method of utilization of the fluid that is separated by the ion transport membrane were compared. Then, the better system was determined, and its performance characteristics were analyzed in detail. The operating temperature of the fuel cell and the pressure ratio of the compressor were varied within the operating conditions of the ITM as the main design variables. The performance of the proposed system was compared with that of a post-combustion system and other oxy-fuel combustion capture systems. The proposed system had 1.70% and 4.0%p higher power and efficiency than the post-combustion capture system, respectively. Furthermore, the purity of the carbon dioxide captured from the proposed system was 97.4%, which is 9.1%p higher than that of the semi-closed cycle oxy-fuel combustion system, while the efficiency was 7.8%p higher. (C) 2019 Elsevier Ltd. All rights reserved.