Abstract
The authors recently proposed a solid oxide fuel cell (SOFC) and closed-cycle MHD combined carbon-dioxide-capturing high-performance power generation system using pure oxygen as the oxidant. This combined system can make the best use of the merit of pure oxygen combustion, while its demerit of efficiency deterioration by large required power for oxygen generation still remains. In the present study, the authors modify this already proposed system and newly propose an improved carbon-dioxide-capturing SOFC/MHD combined power generation system with higher total thermal efficiency. In the system, pure oxygen is only supplied to the afterburner to save the required power for oxygen generation, and pressurized air is selected as the oxidant gas of the SOFC. The saved power amounts to about 5% of the thermal input, resulting in the very high total thermal efficiency of 67.53% (HHV) or 74.94% (LHV), which is considered to be the highest possible value as the total thermal efficiency of carbon-dioxide-capturing systems. The proposed system is worth carrying out further research and development.
