We clarified experimentally that a Ni-Al2O3 catalyst is active for steam reforming of methanol at 450-750 degrees C, and that it results in a different reaction to that obtained when using a CuO-ZnO catalyst, We also analyzed the characteristics of Ni-Al2O3-catalyzed steam reforming in a reformer when snitching fuel from methane to methanol or propane, and vice versa, The flow rates of hydrogen and carbon monoxide in the steam-reformed gas can be kept almost constant by controlling the supply rates of fuel and steam, The methanol decomposition reaction and the propane steam reforming reaction occur mostly near the gas inlet of the catalyst bed, unlike the methane steam reforming reaction, We demonstrated experimentally that by regulating the rates of fuel and steam supplied to a reformer and by using a Ni-Al2O3 reforming catalyst, a phosphoric acid fuel cell power plant generates a continuous constant power of 9.6 kW or 26 kW when the pipeline gas 13A fuel is switched to methanol or propane respectively, and vice versa.