Patent ID: 6969562

Claim:
A fuel cell power generation method utilizing methane fermentation of organic matter, said method comprising: a methane fermentation step for subjecting organic matter to methane fermentation to yield a digestion gas; a pretreatment step for pretreating the digestion gas yielded in said methane fermentation step; a hydrogen production step for producing a hydrogen-containing gas from the pretreated gas in said pretreatment step; and a fuel cell power generation step for supplying the hydrogen-containing gas produced in said hydrogen production step to a fuel cell to generate electricity; wherein said pretreatment step comprises an alkaline absorption step for absorbing carbon dioxide or carbon dioxide and hydrogen sulfide contained in the digestion gas yielded in said methane fermentation step into an alkaline absorbent solution to separate carbon dioxide or carbon dioxide and hydrogen sulfide from the digestion gas, wherein, in said alkaline absorption step, the digestion gas is brought into counterflow contact with the alkaline absorbent solution to absorb carbon dioxide or carbon dioxide and hydrogen sulfide into the alkaline absorbent solution to enrich the concentration of methane; and further comprising: a heat exchange step for heating the alkaline absorbent solution which has absorbed carbon dioxide or carbon dioxide and hydrogen sulfide therein in said alkaline absorption step, by waste heat generated in said hydrogen production step and/or said fuel cell power generation step; and a regeneration step for regenerating the alkaline absorbent solution by bringing the alkaline absorbent solution heated in said heat exchange step into counterflow contact with a cathode vent gas discharged from said fuel cell power generation step or a combustion exhaust gas discharged from said hydrogen production step to strip carbon dioxide or carbon dioxide and hydrogen sulfide from the alkaline absorbent solution.