A method of producing reformed gas as part of a Fischer-Tropsch (“FT”) hydrocarbon synthesis is disclosed, including the steps of superheating at least a first portion of an FT tail gas produced as a by-product of an FT synthesis process, and forming a mixed gas by injecting at least a portion of an FT water stream, produced as a by-product of an FT synthesis process, into the superheated FT tail gas to form a mixed gas. The mixed gas is used as a feed to a front end of a syngas preparation unit. The amount of at least a portion of the FT water stream is selected to keep the mixed gas at least mostly and preferably entirely in a vapor phase. In some embodiments, a water-gas shift reactor converts the mixed gas to a converted mixed gas upstream of the front end. Other methods, apparatuses and systems are disclosed.