A hydrogen-containing gas suitable for use in a fuel cell, especially in a proton
exchange membrane fuel cell, is produced from a digestion gas (b) yielded in methane
fermentation of organic matter (a), and is then supplied to the fuel cell to generate
electricity. A fuel cell power generation method comprises a methane fermentation
step (A) for subjecting organic matter to methane fermentation, a pretreatment
step (B) for pretreating digestion gas yielded in the methane fermentation step,
a hydrogen production step (C) for producing hydrogen-containing gas (c) from the
gas which has been pretreated in the pretreatment step, and a fuel cell power generation
step (D) for supplying the hydrogen-containing gas produced in the hydrogen production
step to a fuel cell to generate electricity. The pretreatment step comprises an
alkaline absorption step (B1) for absorbing carbon dioxide or carbon dioxide and
hydrogen sulfide contained in the digestion gas yielded in the methane fermentation
step into an alkaline absorbent solution.