NOVELTY - Electricity-generation system processes livestock excrement process sewage gas using anaerobic fermentation, elimination, modification and hydrogen refinement processes. Fluidized-bed reactor (4) is used as an apparatus for modification process. Between hydrogen purification process and fuel cell, purified hydrogen is re-refined by contacting with noble metal group hydrogen separation membrane.    USE - For generating electricity using the livestock excrement process sewage gas for use in gas working mold internal combustion engine (claimed) such as micro gas turbine and gas engine.    ADVANTAGE - The electricity generation system effectively uses the sewage gas produced by the livestock excrement process. Since a fluidized bed reactor is used as a modification apparatus, equalization of reaction is achieved. The deterioration rate of the catalyst is reduced. The fuel cell has improved durability.    DETAILED DESCRIPTION - An electricity-generation system processes the livestock excrement process sewage gas using an anaerobic fermentation process, an elimination process, a modification process and a hydrogen refinement process. The fermentation process carries out the fermentation of the livestock excrements using a methane microbe as a pretreatment. A crepuscular-rays synthesis bacteria changes the organic substance in the excrement into an organic acid to obtain a sewage gas. The elimination process removes a harmful substance from the sewage gas generated during fermentation. The modification process modifies the eliminated sewage gas in hydrogen. The hydrogen purification process purifies the obtained modified hydrogen gas. A fuel cell (7) carries out an electricity generation using the purified hydrogen gas. A fluidized-bed reactor (4) is used as an apparatus for the modification process. Between the hydrogen purification process and the fuel cell, the purified hydrogen is re-refined by contacting with a noble metal group hydrogen separation membrane.    DESCRIPTION OF DRAWING(S) - The figure shows the flow sheet of the electricity generation system. (Drawing includes non-English language text).    Fluidized bed reactor (4)    Fuel cell (7)