Installation and method for producing liquefied methane

A plant for the production of liquefied methane comprising a circuit comprising, arranged in series, a means for the generation of methane from hydrogen and carbon dioxide, a means for drying the gas mixture produced by the methane generation means, a purification means configured to remove carbon dioxide from the gas mixture dried in the drying means, a liquefier configured to liquefy the methane contained in the gas mixture purified in the purification means, and a liquefied gas storage facility configured to store the methane liquefied by the liquefier, the plant being comprising a hydrogen separation device configured in order to remove at least a part of the hydrogen from the fluid mixture produced by the liquefier before entering the storage facility, and wherein the hydrogen separation device comprises a first phase-separating vessel comprising an inlet connected to an outlet of the liquefier, in order to receive the fluid mixture produced by the liquefier, and two outlets respectively connected to a pipe for transfer of liquid to the storage facility and a pipe for transfer of gas to the methane generation means, wherein the hydrogen separation device is connected to the outlet of the liquefier via an expansion valve, the plant being configured to cool the mixture of fluids at the outlet of the liquefier to a temperature lower than the equilibrium temperature of pure methane.