Combined Cycle of Solid Oxide Fuel Cell and Turbines with the Aim of Separating CO₂ Gas

Abstract

For protection of the global environment, suppression of CO₂ gas emission from power systems is required. In the present paper, separation of CO₂ gas from fossil fuel with a combined SOFC and turbine system is proposed to satisfy this requirement. The results from a model calculation of the system indicate that the total thermal efficiency of the system is higher than 60% (LHV) and increases with increase in fuel utilization and also with decreases in excess air factor, steam carbon ratio, air recirculation ratio and system pressure. Furthermore, CO₂ concentration in the exhaust gas from the present system is 1/10 or less of that from existing heat engines. In addition, CO₂ concentration supply to a CO₂ separator in the system is 10 times as high. This means that the present CO₂ separator can be minimized in volume to about 1/10 of the volume of separators applied to existing systems.