Abstract: Disclosed is an MCFC power generation system and a method for operating the same enabling significant reduction of CO2 emission or substantially zero CO2 emission by minimizing the equipment added to a general power generation facility to a minimum, enabling both high power generation efficiency and high heat recovery efficiency, enabling adjustment of the voltage and output of the fuel cell in a certain range by adjusting the cathode gas composition, enabling great variation of the ratio between the heat and electricity, and thereby enabling variable thermoelectric operation. The MCFC generation system includes a cathode gas circulation system in which the cathode gas is circulated by a cathode gas recycle blower, and a closed loop is formed. Oxygen consumed by power generation is supplied from an oxygen supply plant, and CO2 is supplied from recycled CO2. Combustible components in anode exhaust are burned with oxygen, the resultant gas is cooled, and water is removed.

Abstract: Provided is a hydrogen-recycling MCFC power-generating system that can improve power generation efficiency by effectively utilizing fuel gas having the hydrogen included in anode exhaust as the main component, and that can reduce the amount of carbon dioxide discharged by separating and recovering the carbon dioxide. The system is provided with a molten carbonate fuel cell (9), a carbon dioxide separating system (20) that separates and recovers a portion of the carbon dioxide from the anode exhaust (AE) from the fuel cell, a gas mixer that mixes recycled fuel gas (RF) after a portion of the carbon dioxide has been separated from the anode exhaust with new fuel gas (F) that is supplied from outside to make a mixed fuel gas (MF), a fuel gas heater (13) that diverts a portion of the mixed fuel gas, preheats it to a constant temperature and adds reforming steam (STM), and a multistage pre-converter (14) that performs a reforming reaction and a methanation reaction of the mixed fuel gas simultaneously.