In this work, we report a novel, simple and convenient method for CO2 methanation and synthesis of hydrogen and methane fuel mixtures at room temperature. CON-free hydrogen and methane fuel mixtures have been successfully generated for the first time in one pot at room temperature through the solid/gas mechanochemical reactions of selected light metal hydrides with CO2. It is noted that methane is the sole hydrocarbon product in the mechanochemical reactions of selected light metal hydrides with CO2, which suggests that the mechanochemical reduction of CO2 by light metal hydrides is highly selective. The yield and mole fraction of methane in the gas product depend mainly on the species of light metal hydride, rate and duration of ball milling, and CO2 pressure.