The invention relates to a method for treating and feeding natural gas from a tank for storing liquefied gas storage to an apparatus for generating power, and to a burner of an apparatus for generating power in a ship, said method comprising the following consecutive steps: supplying power to the apparatus for generating power, during which step natural gas is fed through a phase separator that returns a heavy fraction of the natural gas containing the hydrocarbons having the longest carbon chains to the tank as condensate and feeding a light fraction of the natural gas containing the hydrocarbons having the shortest carbon chains to the apparatus for generating power; and then recovering the heavy fraction of the natural gas, during which step natural gas is carried from the tank to the burner, bypassing said phase separator.