NOVELTY - The system has synthesis-gas generator (3) that manufactures the synthesis gas which consists of hydrogen and carbon monoxide, and the fuel synthesizer (6) synthesizes a fuel from a synthesis gas. A test cell performs the electrical restoration of water vapor and a carbon dioxide. A supply path supplies a synthesis gas to a fuel synthesizer from a synthesis-gas generator and circulates the entrance of a synthesis-gas generator through a portion of emitted synthesis gas in arbitrary flow volume and a ratio.    USE - Fuel combination system.    ADVANTAGE - The fuel combination system converts the electric power derived from natural energy into the carrier for nearby transport or storage at high efficiency from hydrogen is constructed easily. The fuel combination system suppresses the oxidative degradation of an electrode by circulating the synthesis gas. The electrochemical reduction of the carbon dioxide gas by the solid oxide form electrolyzer is not observed. The energy carrier in storage and conveyance to manufacture methanol and a dimethyl ether is attained with high efficiency.    DETAILED DESCRIPTION - The fuel synthesizer synthesizes alcohol, ether or the fuel of a hydrocarbon using the synthesis gas emitted by the synthesis gas generator. The operating temperature of the solid oxide form electrolyzer, and the molar flow rate of the water vapor supplied to the solid oxide form electrolyzer. The molar flow rate of the carbon dioxide gas supplied to the solid oxide form electrolyzer, while producing the molar flow rate of the hydrogen in the solid oxide form electrolyzer. The carbon dioxide gas of the carbon monoxide is produced in the solid oxide form electrolyzer using a predetermined formula. The dimethyl ether is combined with synthetic methanol in the reactor by the latter stage of the fuel synthesizer. The operating temperature of the solid oxide form electrolyzer, and the molar flow rate of the water vapor supplied to the solid oxide form electrolyzer is determined. The molar flow rate of the carbon dioxide gas is supplied to the solid oxide form electrolyzer. An INDEPENDENT CLAIM is included for fuel combination method.    DESCRIPTION OF DRAWING(S) - The drawing shows the explanatory view of the fuel combination system.    Water tank (1)    Liquid-dioxycarbon gas cylinder (2)    Synthesis-gas generator (3)    External power supply (5)    Fuel synthesizer (6)